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>>THANK YOU FOR COMING.

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TODAY EITHER IN PERSON OR

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VIRTUALLY.

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WE HAVE A NICE TURN OUT TODAY.

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I'M KATIE KENT, SENIOR

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INVESTIGATOR AT THE NIDCD AND

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IT'S MY PLEASURE TO INTRODUCE

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TODAY'S NEUROSCIENCE SEMINAR

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SPEAKER RYAN HIBBS, WORLD CLASS

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STRUCTURAL BIOLOGIST.

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IVY KNOWN RYAN SINCE WE WERE

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GRADUATE STUDENTS AT UCSD, AT

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THE UNIVERSITY OF SAN DIEGO

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WHICH DOES SEEM LIKE A LIFETIME

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AGO.

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VERY MEMORABLE, RYAN HELPED ME

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PICK OUT MY FIRST SURF BOARD AND

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WE HAD A LOT OF FUN TRIPS ON THE

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BAJA PENINSULA.

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WHEN HE WASN'T SURFING HE DID

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RESEARCH IN STRUCTURAL BIOLOGY

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AND HE STUDIED LIGAND

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SPECIFICITY AND CONFIRMATIONAL

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CHANGES IN ION CHANNEL BINDING

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DOMAIN.

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I'M NOT A STRUCTURAL BIOLOGIST,

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I FIND IF FASCINATING, I THINK I

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GOT THAT RIGHT AND AFTER A

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SUCCESSFUL Ph.D. WE STARTEDIE

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POST DOC AT OSU AND PORTLAND IS

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A WONDERFUL PLACE TO DO YOUR

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POST DOC AND I DID MINE AS WELL,

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SO I GET TO HANG OUT WITH RYAN

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SOMEWHERE, BUT IN THE LAB, RYAN

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STARTED LEARNING THE NUANCES OF

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CRYSTALLOGRAPHY AND SOLVEDLET

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STRUCTURALLY UPPER OF AN LIGAND

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ION CHAN AND HE WILL THIS

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STRUCTURE ALONG WITH SUBSEQUENT

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STRUCTURES THAT HIS LAB SOLVED

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ARE TRULY LANDMARK

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ACCOMPLISHMENTS BECAUSE THESE

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SYNAPTIC PROTEINS RESIDE IN THE

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MEMBRANE, AND HAD BEEN

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PREVIOUSLY EXTREMELY DIFFICULT

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TO CRYSTALLIZE TO GET THE

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STRUCTURALLY UPPER OF SO IT'S

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VERY AMAZING AND HEARD LOTS OF

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REALLY AMAZING PAPERS THAT WOULD

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MAKE ANY STRUCTURAL BIOLOGIST,A

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MAZING, SO IT'S BEEN FUN TO

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FOLLOW HIS CAREER, NONETHELESS,

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SO HE'S IN HIS LAB, HE'S NOT

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ONLY DO CRYSTALLOGRAPHY BUT ALSO

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CRYOEM APPROACHES TO OBTAIN NICE

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HIGH RESOLUTION 3D STRUCTURES OF

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THESE SYNAPTIC PROTEINS WITH

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AGAIN A FOCUS ON LIGAND

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RECEPTORS SOME OF WHICH WE WILL

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LEARN ABOUT TODAY MULTIPLE

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CONFIGURURATIONS WHICH I'VE

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LEARNED IS IMPORTANT IF YOU WANT

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TO KNOW NOT ONLY HOW THE NATURAL

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LIGAND BINDS BUT HOW THEY MIGHT

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INTERACT WITH THE RECEPTOR OR

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MAKE DIFFERENT THERAPEUTIC DRUG

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TARGETS AS WELL.

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AND AFTER HIS CONTINUED SUCCESS

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ADDED UT SOUTHWESTERN, HE WILL

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MOVE HIS LAB BACK TO UCSD IN THE

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SPRING WHERE HE BEGAN HIS WORK

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IN STRUCTURAL BIOLOGY DOING MORE

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GREAT WORK AND GETTING TO GO DO

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MORE SURFING AS WELL, AGAIN, AND

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SO IT'S REALLY MY PLEASURE TO

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HAVE YOU HERE TODAY, RYAN SO

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THANK YOU FOR COMING.

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BUT BEFORE WE HEAR ABOUT YOUR

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MOST RECENT WORK I WANT TO

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REMIND EVERYBODY TO USE A

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MICROPHONE SO PEOPLE CAN HEAR

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YOU, AND I WILL BE CHECKING MY

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E-MAIL AND WILL BE ABLE TO ASK

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QUESTIONS YOU SEND IN THROUGH

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THE LIVE CHAT.

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SO THANK YOU.

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GO AHEAD, ALL YOURS, RYAN.

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[ APPLAUSE ]

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>>THANK YOU KATIE AND
THANK YOU

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ALL FOR COMING.

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I APPRECIATE YOUR PATIENCE, I'VE

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RESCHEDULED AND CANCELED THIS

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SEMINAR, KENT INVITED ME AND

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THEN THE PANDEMIC HAPPENED AND I

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DIDN'T WANT TO DO IT VIRTUALLY

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AND SO I'M JUST WONDERFUL POETIC

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BE HERE, WONDERFUL FRIENDS AND

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COLLEAGUES, PEOPLE LIKE KATIE.

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SO I'M GLAD TO BE HERE.

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I NL EXCITED TO TELL YOU ABOUT A

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PROJECT WE'VE BEEN LOOKING ON

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FOR A LONG TIME TRYING TO GET A

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STRUCTURE OF THIS PROTOTYPICAL

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ION CHANNEL, THE RECEPTOR, THE

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STAR OF THE SHOW TODAY, IT'S IN

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THE MIDDLE OF THE SCREEN HERE,

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THE CRYOEM RECEPTOR AND A THEME

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00:04:04,840 --> 00:04:07,840
SHALL BE PRESENT THROUGHOUT THE

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TALK IS HOW NATURAL PRODUCTS AND

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TALKS HAVE BEEN USED TO PROBE

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THE STRUCTURE AND FUNCTION AND

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PHYSIOLOGY OF THIS FAMOUS

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CHANNEL, SO ON THE LEFT WE HAVE

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AN INDIAN FROM SOUTH AMERICA WHO

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HAS CODED THE TIPS OF THEIR

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ARROWS WITH THE EXTRACT FROM THE

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PLANT THAT CONTAINS THE MOLECULE

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[INDISCERNIBLE] AND MORE

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SPECIFICALLY, THAT BINDS AS A

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COMPETITIVE ANTAGONIST AT THE

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MUSCLE NICTINNIC, THE JUNCTION

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00:04:42,160 --> 00:04:43,760
CAUSING FLACCID PARALYSIS OF THE

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MUSCLES SO IF PARALYZE IT IS THE

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PREY AND THEY CAN CAPTURE THEIR

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PREY.

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SNAKES HAVE--DOES DIFFERENT

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THINGS IN TERMS OF STRUCTURE

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FUNCTION RELATIONSHIPS AND BOTH

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OF THESE HAVE BEEN USED TO

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CHARACTERIZE THE RECEPTOR AND I

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WILL MAKE AN ARGUMENT TODAY THAT

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THERE'S STILL MORE TO LEARN FROM

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THESE INTERESTING NATURAL

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PRODUCTS.

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ALL RIGHT, SO, GOING FORWARD

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LET'S SEE HERE, NO. 

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CAN I GO?

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OH, I SEE, AKRO BAT, IT'S TRYING

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TO UPDATE, OKAY, GOOD.

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SO ALMOST ALL THE WORK I'M GOING

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TO TALK ABOUT TODAY WAS DONE BOO

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BY A TALENTED POST DOC IN THE

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LAB [INDISCERNIBLE].

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SO NICK O 10IC RECEPTORS THEY

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ARE PART OF A FAMILY OF

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RECEPTORS, THIS CHANNEL FAMILY

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CAN BE DIVIDED INTO 2 BROAD

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CATEGORIES THOSE WHOSE INTRINSIC

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CHANNELS ARE SELECTED FOR CAT

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IONS AND 5 H3 T SEROTONIN

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RECEPTORS.

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THE OTHER SIDE OF THE FAMILY IS

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A SELECTIVE BRANCH INCLUDING

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GABBA A RECEPTORS AND GLUE

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MARIOUS SEEN RECEPTORS, THE CAT

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ION SELECTED BRANCH ARE

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GENERALLY NONSELECTIVE AMONG CAT

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IONS AND SOME LET CALCIUM AND

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SYNAPTIC MISSION, AND THE AN ION

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CHANNELS ARE PERMEABLE TO

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CHLORIDE, AND BECAUSE THE

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MEMBRANE POTENTIAL AT WHICH

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CHLORIDE IS AN EQUILIBRIUM FOR

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THE NEURON WHEN YOU OPEN ANN ION

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CHANNEL LIKE THE GABBA A

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RECEPTOR THEY TYPICALLY, POSE

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EXCITABILITY AND PLAY INHIBITORY

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ROLES IN SYNAPTIC TRANSMISSION.

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NOW REGARDLESS OF THE

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NEUROTRANSMITTER PHARMACOLOGY

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AND THE CHANNEL PROPERTIES THEY

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SHARE A CONSERVED ARCH TEJTURE

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SO THEY'RE ION CHANNELS, THEY

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CAN BE HOMOPENTINE REGIMEN MERS

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OR HETEROGENEOUSERY PENTAMERS,

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PHYSIOLOGICALLY IN HUMANS,

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THEY'RE NEARLY ALL HETEROPENTINE

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REGIMEN MERS AS AN EXAMPLE,

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THERE ARE 16 SUBUNITS, THAT CAN

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ASSEMBLE IN A LARGE BUT DEFINED

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NUMBER OF WAYS TO MAKE

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FUNCTIONAL PHYSIOLOGICALLY

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RELEVANT CHANNELS, ONLY 1 OF

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THOSE 16 SUBUNITS, THE ALPHA 7

185
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ASSEMBLES INTO FUNCTIONAL

186
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PHYSIOLOGICALLY HOMOPENTINE

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REGIMEN MERS, THE OTHER ASSEMBLE

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INTO OBLIGATE HETEROMERS WITH

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THE SUBUNIT COMPOSITIONS, SO

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REGARDLESS OF THE STOIKIOTETRY,

191
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EACH SUBUNIT CHAIRS A COMMON

192
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TOPOLOGY.

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SO FROM'S A LARGE EXTRA CELLULAR

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AMINO TERMINAL DOMAIN SO THIS IS

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WHERE NEUROTRANSMITTERS BIND,

196
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WITH THE SUBUNITS IN THE PENTINE

197
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REGIMEN MER, FOR TRANSMEMBRANE

198
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SPANNING ALPHA HELIXESS FOR THE

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00:07:32,880 --> 00:07:35,520
SECOND 1 CALLED M2, THE SECOND 1

200
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OFF THE HELIX IS THE 1S THAT

201
00:07:37,560 --> 00:07:39,280
LINES THE ION CHANNEL, SO IT

202
00:07:39,280 --> 00:07:40,520
DETERMINES MOST OF THE

203
00:07:40,520 --> 00:07:41,960
PERMEATION PROPERTIES AND CAT

204
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ION AND SELECTIVITY.

205
00:07:42,400 --> 00:07:43,960
SO THIS IS THE ONLY CHANNEL

206
00:07:43,960 --> 00:07:45,920
FAMILY I KNOW OF THAT HAS

207
00:07:45,920 --> 00:07:49,400
EVOLVED, THEY USE A COMMON

208
00:07:49,400 --> 00:07:52,040
SCAFFOLD TO OPPOSING ACTIVITIES

209
00:07:52,040 --> 00:07:53,440
SO THE TETRAMERIC, THE THEY'RE

210
00:07:53,440 --> 00:07:54,840
ALL CAT ION CHANNELS SO IT'S

211
00:07:54,840 --> 00:07:56,160
INTERESTING TO TRY TO LEARN FROM

212
00:07:56,160 --> 00:07:57,760
THESE STUDIES ABOUT HOW THIS

213
00:07:57,760 --> 00:08:02,400
COMMON SCAFFOLD CAN GIVE RISE TO

214
00:08:02,400 --> 00:08:03,080
CHANNELS OPPOSING SELECTIVITYS.

215
00:08:03,080 --> 00:08:04,640
OKAY, SO THESE ARE THE

216
00:08:04,640 --> 00:08:07,160
PENTAMERRIC CHANNELS AND WE WILL

217
00:08:07,160 --> 00:08:09,880
FOCUS NOW IN ON NICOTINIC

218
00:08:09,880 --> 00:08:10,920
RECEPTORS FOR THE REST OF THE

219
00:08:10,920 --> 00:08:12,400
TALK BUT I WANT TO MENTION A

220
00:08:12,400 --> 00:08:14,160
DRUG CLASS WE WILL GET INTO AT

221
00:08:14,160 --> 00:08:16,960
THE VERY END AND THAT IS GENERAL

222
00:08:16,960 --> 00:08:18,400
AN THESAURUSSICS AND THIS WILL

223
00:08:18,400 --> 00:08:20,840
COME UP AT THE END BUT WE'VE

224
00:08:20,840 --> 00:08:24,640
BEEN WORKING ON GABBA A

225
00:08:24,640 --> 00:08:25,560
RECEPTORS AND NICOTINIC RECEPTS

226
00:08:25,560 --> 00:08:28,120
IT IN MY LAB AND THESE ARE THE

227
00:08:28,120 --> 00:08:32,080
FAMOUS TARGET OF MANY

228
00:08:32,080 --> 00:08:34,040
ANESTHETICS AND THE WAY

229
00:08:34,040 --> 00:08:34,760
GENERALLAN ESTIMATE THADTHETICS

230
00:08:34,760 --> 00:08:36,640
WORK BROADLY, THEY DON'T ALL

231
00:08:36,640 --> 00:08:38,840
ACTOT SAME CHANNELS, THEY ACT

232
00:08:38,840 --> 00:08:39,400
THROUGH POLYPHARMACOLOGY

233
00:08:39,400 --> 00:08:40,320
MECHANISMS SO THEY DO DIFFERENT

234
00:08:40,320 --> 00:08:42,560
THINGS TO DIFFERENT KINDS OF

235
00:08:42,560 --> 00:08:44,160
CHANNELS, AND BROADLY THE WAY

236
00:08:44,160 --> 00:08:44,800
GENERALLAN ESTIMATE THADTHETICS

237
00:08:44,800 --> 00:08:47,640
DO AND WHAT THEY DO IS THEY

238
00:08:47,640 --> 00:08:49,360
POTENTIAL INHIBITORY CHANNELS

239
00:08:49,360 --> 00:08:51,400
AND INHIBIT EXCITATORY CHANNELS

240
00:08:51,400 --> 00:08:53,960
SO THEY'LL--THE SAME MOLECULE

241
00:08:53,960 --> 00:08:55,800
LIKE PROPOFOL WILL POTENTIAL

242
00:08:55,800 --> 00:09:00,400
GABBA A RECEPTORS AND INHIBIT

243
00:09:00,400 --> 00:09:01,320
NICOTINIC RECEPTORS SO WE WILL

244
00:09:01,320 --> 00:09:03,400
LOOK AT HOW THEY WORKT ON THE

245
00:09:03,400 --> 00:09:06,440
NICOTINIC RECEPTORS AT THE VERY

246
00:09:06,440 --> 00:09:06,680
END.

247
00:09:06,680 --> 00:09:07,640
THIS DETERMINES WHERE THEY'RE

248
00:09:07,640 --> 00:09:10,680
FOUND IN THE BODY, WHAT THEY

249
00:09:10,680 --> 00:09:11,160
DID, THE PHARMACOLOGY,

250
00:09:11,160 --> 00:09:12,280
BIOPHYSICS, WE WORKED ON A FEW

251
00:09:12,280 --> 00:09:13,920
OF THEM, I WILL TAKE YOU THROUGH

252
00:09:13,920 --> 00:09:16,160
THIS TO GIVE YOU A SENSE IN THE

253
00:09:16,160 --> 00:09:18,600
DIVERSITY IN THE FAMILY.

254
00:09:18,600 --> 00:09:20,760
THESE LITTLE COLORED CIRCLES

255
00:09:20,760 --> 00:09:22,960
HERE ARE WHERE NEUROTRANSMITTERS

256
00:09:22,960 --> 00:09:24,400
AND OTHER AGONIST BIND THE

257
00:09:24,400 --> 00:09:26,760
INTERFACES OF ALPHA AND NONALPHA

258
00:09:26,760 --> 00:09:28,800
SUBUNITS SO THIS IS THE MOST

259
00:09:28,800 --> 00:09:30,080
ABUNDANT ASSEMBLY IN THE BRAIN

260
00:09:30,080 --> 00:09:32,480
AND IF YOU KNOCK OUT EITHER

261
00:09:32,480 --> 00:09:34,280
ALPHA 4 BATTA 2 SUBUNITS THEY

262
00:09:34,280 --> 00:09:35,800
WILL NO LONGER ADMINISTER

263
00:09:35,800 --> 00:09:37,800
NICOTINE SO THIS RECEPTOR FORNLS

264
00:09:37,800 --> 00:09:43,000
THE HIGH AFFINITY BINDING SITE,

265
00:09:43,000 --> 00:09:47,080
AND EFFICACIOUS AND SMOKING

266
00:09:47,080 --> 00:09:47,320
CESSATION.

267
00:09:47,320 --> 00:09:50,240
ALPHA 3 BETA 4 THIS RECEPTOR

268
00:09:50,240 --> 00:09:52,560
SUBTYPE IS FAMOUSLY CALLED THE

269
00:09:52,560 --> 00:09:54,040
GANGLIONIC RECEPTOR BECAUSE IT'S

270
00:09:54,040 --> 00:09:55,920
FOUND IN THE AUTONOAMIC GANGLIA

271
00:09:55,920 --> 00:09:58,360
THIS IS PART OF THE PERIPHERAL

272
00:09:58,360 --> 00:10:00,320
NERVOUS SYSTEM, THEY'RE'S

273
00:10:00,320 --> 00:10:01,400
SYMPATHETIC AND PARASYMPATHETIC

274
00:10:01,400 --> 00:10:02,400
BRANCHES AND, NEURONS COME OUT

275
00:10:02,400 --> 00:10:03,920
OF THE SPINAL CORD, FORM A

276
00:10:03,920 --> 00:10:05,320
SYNAPSE BEFORE THEY GET TO THE

277
00:10:05,320 --> 00:10:07,040
TARGET ORGANS AND AT THAT

278
00:10:07,040 --> 00:10:07,840
SYNAPSE THE NEUROTRANSMITTER IS

279
00:10:07,840 --> 00:10:10,040
THE CHOLINE AND THE POST

280
00:10:10,040 --> 00:10:13,680
SINATTIC RECEPTOR IS ALWAYS THE

281
00:10:13,680 --> 00:10:15,080
ALPHABETTA TINNIC 3 AND 4

282
00:10:15,080 --> 00:10:18,960
RECEPTOR SO WHY AM I SHOWING YOU

283
00:10:18,960 --> 00:10:20,400
A HEROIN NEEDLE HERE?

284
00:10:20,400 --> 00:10:22,720
WELL THEY'RE NOT JUST FOUND ON

285
00:10:22,720 --> 00:10:23,760
THE PERIPHERY, THEY'RE ON THE

286
00:10:23,760 --> 00:10:27,360
BRAIN AND REASON FOR REWARD AND

287
00:10:27,360 --> 00:10:28,160
ADDICTION, SPECIFICALLY

288
00:10:28,160 --> 00:10:30,000
[INDISCERNIBLE] AND SELECTIVE

289
00:10:30,000 --> 00:10:32,080
ANTAGONIST FOR ALPHA 3 BETA 4

290
00:10:32,080 --> 00:10:32,920
ARE REMARKABLY EFFICACIOUS IN

291
00:10:32,920 --> 00:10:36,520
BROAD FORMS OF ADDICTION, SO

292
00:10:36,520 --> 00:10:38,480
OPIOIDS AND AMPHETAMINES, KRO

293
00:10:38,480 --> 00:10:39,560
CAIN, ALCOHOL, NICOTINE, EVEN

294
00:10:39,560 --> 00:10:40,240
SUGAR.

295
00:10:40,240 --> 00:10:43,440
SO THERE'S EFFORTS UNDER WAY TO

296
00:10:43,440 --> 00:10:44,640
DEVELOP SELECTIVE COMPOUNDS AND

297
00:10:44,640 --> 00:10:46,160
DON'T BROTHER THE RECEPTORS IN

298
00:10:46,160 --> 00:10:49,920
THE PERIPHERY SOMEHOW IN

299
00:10:49,920 --> 00:10:50,480
ADDICTION.

300
00:10:50,480 --> 00:10:53,960
ALPHA 7 IS THE BIZARRE MEMBER OF

301
00:10:53,960 --> 00:10:56,360
THE FAMILY, AND IT'S FOUND NOT

302
00:10:56,360 --> 00:10:57,800
ONLY IN THE BRAIN, VERY

303
00:10:57,800 --> 00:11:00,400
ABUNDANTLY BUT ALSO IN THE

304
00:11:00,400 --> 00:11:02,040
PERIPHERY AND NONNEURONAL CELLS,

305
00:11:02,040 --> 00:11:03,680
NONEXCITABLE CELLS, FOUND IN

306
00:11:03,680 --> 00:11:04,400
MACROPHAGES AND EPITHELIAL CELLS

307
00:11:04,400 --> 00:11:06,720
AND IT'S THOUGHT TO BE VERY

308
00:11:06,720 --> 00:11:07,920
IMPORTANT IN INFLAMMATION, SO

309
00:11:07,920 --> 00:11:10,720
AGONIST IN THE PERIPHERY OF THE

310
00:11:10,720 --> 00:11:12,440
RECEPTOR, CHOLINE RELEASED BY

311
00:11:12,440 --> 00:11:14,840
THE VAGUELE NURVE HAVE POTENT

312
00:11:14,840 --> 00:11:15,360
ANTIINFLAMMATORY EFFECTS.

313
00:11:15,360 --> 00:11:21,720
AND THEN THE FOCUS TODAY, THE

314
00:11:21,720 --> 00:11:31,560
MUSCLENIQUE 

315
00:11:31,560 --> 00:11:35,760
MUSCLE NICOTINIC RECEPTOR, AND

316
00:11:35,760 --> 00:11:38,920
THEN IN  ADULTS THE GAMMA IS

317
00:11:38,920 --> 00:11:39,280
REPLACED.

318
00:11:39,280 --> 00:11:41,760
SO A GOOD PLACE TO START IS WITH

319
00:11:41,760 --> 00:11:45,720
CLAUDE AND COLLEAGUES, HE GOT

320
00:11:45,720 --> 00:11:56,240
AHOLD OF THIS STRICLNOS PLANTS

321
00:12:02,160 --> 00:12:06,240
THAT THE POISON THEY HAD.

322
00:12:06,240 --> 00:12:09,240
AND THEN JOHN NEW PORT LANGLY

323
00:12:09,240 --> 00:12:11,040
FAME USUALLY COINED THE SERM

324
00:12:11,040 --> 00:12:12,480
RECEPTIVE SUBSTANCE, CONCEPT

325
00:12:12,480 --> 00:12:14,160
ULTIMATELYIZING THE NOTION OF A

326
00:12:14,160 --> 00:12:15,920
CELL SURFACE RECEPTOR AND HE WAS

327
00:12:15,920 --> 00:12:17,000
CONTRASTING THE ACTIONS OF

328
00:12:17,000 --> 00:12:18,600
NICKEE TEEN SO THIS WAS TOBACCO

329
00:12:18,600 --> 00:12:20,360
PLANT AND LEAVES AND FLOWERS,

330
00:12:20,360 --> 00:12:22,840
NICKEE TEEN IS AN AGONIST FOR

331
00:12:22,840 --> 00:12:24,480
THESE RECEPTORS CONTRASTING THAT

332
00:12:24,480 --> 00:12:25,840
WITH THE ANTAGONIST AND THE

333
00:12:25,840 --> 00:12:26,920
RECEPTORS AND FIRST KIND OF

334
00:12:26,920 --> 00:12:29,440
MODEL CITIZEN LEAKULAR

335
00:12:29,440 --> 00:12:29,960
PHARMACOLOGY EXPERIMENTS.

336
00:12:29,960 --> 00:12:33,240
SO WHY DO WE KNOW SO MUCH ABOUT

337
00:12:33,240 --> 00:12:34,440
THE MUSCLE NICOTINIC RECEPTOR,

338
00:12:34,440 --> 00:12:41,200
WE HAVE THESE ALSO IMPORTANTLY,

339
00:12:41,200 --> 00:12:42,880
DISCOVERED THAT ELECTRIC FISH

340
00:12:42,880 --> 00:12:46,960
AND EELS HAVE THEIR ELECTRIC

341
00:12:46,960 --> 00:12:49,240
ORGANS ARE PACKED WITH

342
00:12:49,240 --> 00:12:50,880
CRYSTALLINE DENSITY OF ION

343
00:12:50,880 --> 00:12:53,840
CHANNELS THAT HOMOLOGOUS TO THE

344
00:12:53,840 --> 00:12:56,760
CHO LINE RECEPTORS AND THESE

345
00:12:56,760 --> 00:12:59,600
PROVIDE AN ABUNDANT NATURAL

346
00:12:59,600 --> 00:13:01,360
RESOURCE FOR CHEMISTS AND

347
00:13:01,360 --> 00:13:01,800
BIOLOGIST TO STUDY.

348
00:13:01,800 --> 00:13:03,760
SO HOW DO YOU ISOLATE THIS?

349
00:13:03,760 --> 00:13:05,920
YOU NEED AN AFFINITY AGENT AND

350
00:13:05,920 --> 00:13:09,280
THAT CAME IN THE FORM OF SNAKE

351
00:13:09,280 --> 00:13:11,720
VENOM TOXINS, 3 FINGERED VENOM

352
00:13:11,720 --> 00:13:15,280
TOXINS THAT BIND IRREVERSIBLY TO

353
00:13:15,280 --> 00:13:15,800
NICOTINIC RECEPTORS.

354
00:13:15,800 --> 00:13:17,760
AND THEN THEY PUT THESE

355
00:13:17,760 --> 00:13:20,680
TOGETHER, THE ABUNDANT NATURAL

356
00:13:20,680 --> 00:13:22,040
SOURCE, AFFINITY REAGENT, AND

357
00:13:22,040 --> 00:13:23,720
PERFORMED THE FIRST PURIFICATION

358
00:13:23,720 --> 00:13:25,680
OF AN ION CHANNEL AND THESE ARE

359
00:13:25,680 --> 00:13:26,520
THE FIRST ELECTRON MICROGAFFS IN

360
00:13:26,520 --> 00:13:28,040
1 OF THESE AND YOU CAN START TO

361
00:13:28,040 --> 00:13:29,720
SEE IF YOU CAN SEE THAT FAR, I

362
00:13:29,720 --> 00:13:31,320
CAN'T SEE IT FROM HERE BUT THERE

363
00:13:31,320 --> 00:13:32,400
IS LITTLE ROSETTES WITH DOTS IN

364
00:13:32,400 --> 00:13:34,720
THE MIDDLE AND THAT'S LOOKING

365
00:13:34,720 --> 00:13:37,680
DOWN THE LONG AXIS OF THE ION

366
00:13:37,680 --> 00:13:37,920
CHANNEL.

367
00:13:37,920 --> 00:13:38,760
SO REALLY NEAT HISTORY AND THEN

368
00:13:38,760 --> 00:13:41,560
IN TERMS OF STRUCTURAL BIOLOGY,

369
00:13:41,560 --> 00:13:44,480
THE HERO HAS BEEN NIgE L WHO

370
00:13:44,480 --> 00:13:45,320
MERELY SINGLE HANDEDLY FIGURED

371
00:13:45,320 --> 00:13:46,800
OUT HOW TO GET STRUCTURES OF

372
00:13:46,800 --> 00:13:49,400
THIS RECEPTOR SO HE WAS WORKING

373
00:13:49,400 --> 00:13:50,480
WITH THE TORPEDO RAY AND HE

374
00:13:50,480 --> 00:13:52,240
FOUND IF YOU DID A CRUDE

375
00:13:52,240 --> 00:13:53,160
ENRICHMENT OF THESE MEMBRANES

376
00:13:53,160 --> 00:13:55,160
AND YOU LET THEM SIT FOR A

377
00:13:55,160 --> 00:13:56,240
MONTH, SOMETIMES THEY WOULD ROLL

378
00:13:56,240 --> 00:13:58,880
UP INTO THESE BEAUTIFULLY

379
00:13:58,880 --> 00:14:00,400
HELICAL ORDER TUBES, SO THESE

380
00:14:00,400 --> 00:14:01,680
STRAIGHT LINES HERE, THESE ARE

381
00:14:01,680 --> 00:14:04,440
THESE TUBES AND HE CAN THEN USE

382
00:14:04,440 --> 00:14:05,720
THESE APPROACHES TO ROW

383
00:14:05,720 --> 00:14:07,720
CONSTRUCT STRUCTURES OF

384
00:14:07,720 --> 00:14:08,760
INCREASINGLY HIRE RESOLUTION OF

385
00:14:08,760 --> 00:14:11,760
THESE RECEPTORS AND HERE'S 1,

386
00:14:11,760 --> 00:14:13,560
CARVED OUT OF BALSA WOOD AND I'M

387
00:14:13,560 --> 00:14:18,880
GLAD WE DON'T HAVE TO DO BALSA

388
00:14:18,880 --> 00:14:19,600
WOOD RECONSTRUCTIONS IMORP.

389
00:14:19,600 --> 00:14:20,800
THIS IS AMAZING BUT THIS

390
00:14:20,800 --> 00:14:21,920
SPECIFIC EXAMPLE HERE

391
00:14:21,920 --> 00:14:23,400
ILLUSTRATES THE HAZARDS OF

392
00:14:23,400 --> 00:14:25,600
WORKING WITH AT LOW RESOLUTION

393
00:14:25,600 --> 00:14:27,800
WHICH IS THAT 1 CAN MAKE

394
00:14:27,800 --> 00:14:29,880
MISTAKES IN WHERE YOU PUT THINGS

395
00:14:29,880 --> 00:14:31,040
AND THE SUBUNIT DOESN'T BELONG

396
00:14:31,040 --> 00:14:33,560
HERE AND THIS IS GAMMA UNIT

397
00:14:33,560 --> 00:14:34,440
BETWEEN THE 2 ALPHA SUBUNITS

398
00:14:34,440 --> 00:14:38,120
WHICH WAS WORKED OUT BY ANOTHER

399
00:14:38,120 --> 00:14:38,400
BIOCHEMIST.

400
00:14:38,400 --> 00:14:41,200
THIS IS I THINK THE HIGHEST

401
00:14:41,200 --> 00:14:42,000
RESOLUTION STRUCTURE THAT HE'S

402
00:14:42,000 --> 00:14:44,040
BEEN ABLE TO GET TO, 2012, WE

403
00:14:44,040 --> 00:14:48,240
MIGHT CALL DHS SOMETHING LIKE

404
00:14:48,240 --> 00:14:49,200
6-ANGSTROM RESOLUTION, HERE'S

405
00:14:49,200 --> 00:14:50,800
THE EXTRA CELLULAR DOMAIN WHICH

406
00:14:50,800 --> 00:14:52,240
IS MOSTLY BETA STRAPPEDS AND

407
00:14:52,240 --> 00:14:54,000
THESE ARE NOT RESOLVED FROM EACH

408
00:14:54,000 --> 00:14:54,600
OTHER.

409
00:14:54,600 --> 00:14:56,880
THE TRANSMEMBRANE DOMAIN,

410
00:14:56,880 --> 00:14:58,440
TUBEULAR DENSITIES, CLEARLY

411
00:14:58,440 --> 00:15:01,200
ALPHA HELICAL AND YOU CAN SAY, I

412
00:15:01,200 --> 00:15:02,720
LET ABOUT, SOME ABOUT WHERE THE

413
00:15:02,720 --> 00:15:04,640
SUBUNITS ARE, YOU CAN TALK ABOUT

414
00:15:04,640 --> 00:15:06,760
SECONDARY STRUCTURE BUT WHAT'S

415
00:15:06,760 --> 00:15:08,880
MISSING HERE IS RESOLUTION

416
00:15:08,880 --> 00:15:09,760
SUFFICIENT POSITION SIDE CHAINS

417
00:15:09,760 --> 00:15:10,800
WITH CONFIDENCE AND IF YOU WANT

418
00:15:10,800 --> 00:15:12,760
TO TALK ABOUT LIGAND

419
00:15:12,760 --> 00:15:14,240
INTERACTIONS IF YOU WANT TO TALK

420
00:15:14,240 --> 00:15:16,000
ABOUT WHAT'S LINING THE

421
00:15:16,000 --> 00:15:17,560
PERMEATION PATHWAY TO UNDERSTAND

422
00:15:17,560 --> 00:15:18,600
ION SELECTIVITY, YOU NEED TO

423
00:15:18,600 --> 00:15:20,360
KNOW WHERE THE SIDE CHAINS ARE

424
00:15:20,360 --> 00:15:21,760
AND SO THIS IS THE YEAR I

425
00:15:21,760 --> 00:15:23,920
STARTED MY LAB WAS 2012 AND WE

426
00:15:23,920 --> 00:15:25,320
STARTED CHIPPING AWAY AT HOW DO

427
00:15:25,320 --> 00:15:27,800
YOU MAKE THEE RECEPTORS RECOMBIN

428
00:15:27,800 --> 00:15:30,640
ANTLY AND THAT'S WHERE WE WORKED

429
00:15:30,640 --> 00:15:31,640
ON NEURONAL SUBTYPES AND WE

430
00:15:31,640 --> 00:15:33,440
TRIED TO GET RECEPTORS USING

431
00:15:33,440 --> 00:15:34,440
APPROACHES FOR THE MUSCLE

432
00:15:34,440 --> 00:15:36,520
RECEPTOR AND FAILED OVER AND

433
00:15:36,520 --> 00:15:38,160
OVER AGAIN.

434
00:15:38,160 --> 00:15:39,480
WE COULDN'T GET THIS

435
00:15:39,480 --> 00:15:40,960
PENTAMERCOMPRISING 4 DIFFERENT

436
00:15:40,960 --> 00:15:43,520
TYPES OF SUBUNITS TO EXPRESS AT

437
00:15:43,520 --> 00:15:43,960
PRECCABLE LEVELS.

438
00:15:43,960 --> 00:15:45,400
SO WE RECENTLY WENT BACK TO THE

439
00:15:45,400 --> 00:15:46,920
TORPEDE'S RAY AND WORKED WITH A

440
00:15:46,920 --> 00:15:49,600
CHEMIST TO FIGURE OUT HOW TO

441
00:15:49,600 --> 00:15:51,000
ISOLATE THIS IN QUANTITIES AND

442
00:15:51,000 --> 00:15:53,160
QUALITIES SUFFICIENT FOR HIGH

443
00:15:53,160 --> 00:15:54,760
RESOLUTION CRYOEM STUDIES.

444
00:15:54,760 --> 00:15:56,800
SO WE GET SOME OF THE ELECTRIC

445
00:15:56,800 --> 00:15:59,000
ORGAN, WE FRACTIONATE MEMBRANES,

446
00:15:59,000 --> 00:16:01,240
THERE'S, I DON'T KNOW 50 YEARS

447
00:16:01,240 --> 00:16:02,840
OF BEAUTIFUL BIOCHEMISTRY ON

448
00:16:02,840 --> 00:16:04,600
WHAT KIND OF SALT, WHAT Ph,

449
00:16:04,600 --> 00:16:06,720
HOW DO YOU GET RID OF THE SAV

450
00:16:06,720 --> 00:16:08,400
OLDING PROTEINS THAT KEEP IT IN

451
00:16:08,400 --> 00:16:09,760
THE RICE PLACENTA?

452
00:16:09,760 --> 00:16:12,680
DETERMINANTS PRESERVE FUNCTION

453
00:16:12,680 --> 00:16:13,320
AND GOOD BIOCHEMISTRY?

454
00:16:13,320 --> 00:16:17,280
THAT WAS FUN TO READ AND WE

455
00:16:17,280 --> 00:16:17,960
TALKED TO ARTHUR CONLYNN ABOUT

456
00:16:17,960 --> 00:16:19,880
THIS A LOT AND [INDISCERNIBLE]

457
00:16:19,880 --> 00:16:22,080
AND THEN WE EXTRACTED AND HOW DO

458
00:16:22,080 --> 00:16:23,560
WE AFFINITY PURIFY IT SO A

459
00:16:23,560 --> 00:16:27,520
FRIEND AND COLLEAGUE AT UC

460
00:16:27,520 --> 00:16:28,680
BOULDER SIPGHTICIZED A NEW

461
00:16:28,680 --> 00:16:30,640
REAGENT FOR US, SO THIS HAS THIS

462
00:16:30,640 --> 00:16:34,000
AMMONIUM ON THE END OF IT AND WE

463
00:16:34,000 --> 00:16:35,600
TETHER THAT THE PRIMARY MEANS SO

464
00:16:35,600 --> 00:16:37,400
WE CAN ATTACH AND IT WORKS

465
00:16:37,400 --> 00:16:38,040
BEAUTIFULLY.

466
00:16:38,040 --> 00:16:42,240
IN THE ELECTRIC ORGAN 25% OF THE

467
00:16:42,240 --> 00:16:45,720
PROTEIN IS THE NICOTINIC

468
00:16:45,720 --> 00:16:48,080
RECEPTOR SO YOU DON'T HAVE TO DO

469
00:16:48,080 --> 00:16:50,480
MUCH. 

470
00:16:50,480 --> 00:16:52,040
AND NICOTINIC WE ALLUDE OFF THE

471
00:16:52,040 --> 00:16:56,960
COLONY IN 2 WAYS.

472
00:16:56,960 --> 00:16:58,960
ORGANIZATIONSIGEINALLY WE WERE

473
00:16:58,960 --> 00:17:00,480
ALLUDING WITH CARBOCOL, AND THAT

474
00:17:00,480 --> 00:17:03,280
ALLOWED US TO GET STRUCTURES BUT

475
00:17:03,280 --> 00:17:05,160
WE WANTED APO STRUCTURES WITH

476
00:17:05,160 --> 00:17:07,360
ALL KINDS OF MOLECULES BOUND AND

477
00:17:07,360 --> 00:17:08,640
THEN WE SWITCHED TO CHOLINE

478
00:17:08,640 --> 00:17:10,760
WHICH HAS THE SAMEOT END BUT

479
00:17:10,760 --> 00:17:12,040
MUCH LOWER AFFINITY SO WE CAN

480
00:17:12,040 --> 00:17:13,480
ALLUDE OFF THE COLUMN AND RUN

481
00:17:13,480 --> 00:17:15,240
THE FILTRATION AND GET RID OF

482
00:17:15,240 --> 00:17:19,280
CHOLINE AND GET WHATEVER WE WANT

483
00:17:19,280 --> 00:17:19,840
FOUND.

484
00:17:19,840 --> 00:17:21,160
BEAUTIFULLY PURE, AFTER THIS

485
00:17:21,160 --> 00:17:23,800
STEP, AND THEN WHEN WE RUN

486
00:17:23,800 --> 00:17:24,520
ANALYTICAL GEL FILTRATION, WE

487
00:17:24,520 --> 00:17:27,400
SEE A MIXED POPULATION, WE HAVE

488
00:17:27,400 --> 00:17:30,160
A MONITOR MER, DIMER POPULATION,

489
00:17:30,160 --> 00:17:33,160
HERE MONITOR MERMEANS 1

490
00:17:33,160 --> 00:17:34,200
PENTAMERAND DIMER MEANS 2

491
00:17:34,200 --> 00:17:35,520
PENTINE REGIMEN A MERS STUCK

492
00:17:35,520 --> 00:17:36,440
TOGETHER BECAUSE THERE'S A CROSS

493
00:17:36,440 --> 00:17:38,600
LINK IN THE RECEPTOR AT THE

494
00:17:38,600 --> 00:17:41,240
C-TERMINAL RESIDUE OF TELTA DUB

495
00:17:41,240 --> 00:17:42,120
UNITS.

496
00:17:42,120 --> 00:17:42,360
WHY?

497
00:17:42,360 --> 00:17:43,640
DON'T KNOW, MAYBE IMPORTANT FOR

498
00:17:43,640 --> 00:17:46,200
PACKING AT HIGH DENSITY IN THAT

499
00:17:46,200 --> 00:17:48,680
MEMBRANE BUT WE KNOW WE CAN

500
00:17:48,680 --> 00:17:49,880
REDUCE THOSE AND FUNCTION ISN'T

501
00:17:49,880 --> 00:17:51,400
AFFECTED SO WHAT DO WE DO NEXT,

502
00:17:51,400 --> 00:17:53,080
WE HAVE A PURIFICATION APPROACH

503
00:17:53,080 --> 00:17:56,000
BUT WE WANT TO BE SMART ABOUT

504
00:17:56,000 --> 00:17:58,440
HOW WE'RE GOING TO MAKE OUR EM

505
00:17:58,440 --> 00:17:59,640
SAMPLE TO HOPEFULLY PRESERVE

506
00:17:59,640 --> 00:18:02,080
FUNCTIONAL PROTEINS WHEN WE LOOK

507
00:18:02,080 --> 00:18:03,560
AT CONFIRMATIONAL CHANGES, WE

508
00:18:03,560 --> 00:18:05,360
CAN HAVE CONFIDENCE THAT THEY'RE

509
00:18:05,360 --> 00:18:05,600
RELEVANT.

510
00:18:05,600 --> 00:18:08,160
SO WE WANT TO TEST LIPIDS IN

511
00:18:08,160 --> 00:18:09,480
CONSTITUTION TO SEE WHICH

512
00:18:09,480 --> 00:18:12,720
SUPPORT FUNCTION, SO WE TAKEAUR

513
00:18:12,720 --> 00:18:15,400
RECEPTOR, WE ADD LIPIDS AND WE

514
00:18:15,400 --> 00:18:17,800
TRY DIFFERENT COMPOSITIONS OF

515
00:18:17,800 --> 00:18:18,440
LIPIDS.

516
00:18:18,440 --> 00:18:20,160
WE REMOVE DETERGENT WITH THE

517
00:18:20,160 --> 00:18:26,440
BIOBEADS THAT ABSORB THE

518
00:18:26,440 --> 00:18:26,880
DETERGENT.

519
00:18:26,880 --> 00:18:29,360
AND WE DO THIS WITH DIFFERENT

520
00:18:29,360 --> 00:18:31,160
KINDS OF LIPIDS.

521
00:18:31,160 --> 00:18:33,960
WE FOUND SOY [INDISCERNIBLE]

522
00:18:33,960 --> 00:18:35,280
EXTRACT WORKS BEAUTIFULLY AND WE

523
00:18:35,280 --> 00:18:38,120
CAN SEE CHARACTERISTIC OPENING

524
00:18:38,120 --> 00:18:39,040
AT BOTH POSITIVE AND NEGATIVE

525
00:18:39,040 --> 00:18:40,960
VOLTAGES AND WE CAN BLOCK THIS

526
00:18:40,960 --> 00:18:41,160
TOXIN.

527
00:18:41,160 --> 00:18:41,920
SO WE'RE HAPPY TO ABOUT THAT SO

528
00:18:41,920 --> 00:18:44,600
THEN WE TAKE OUR PURIFIED

529
00:18:44,600 --> 00:18:45,480
RECEPTOR AND DETERNLG AND THEN

530
00:18:45,480 --> 00:18:46,640
THE SIEWTION THE SAME

531
00:18:46,640 --> 00:18:48,480
COMPENSATION AND WE ADD A NANO

532
00:18:48,480 --> 00:18:54,040
DISK AND IN THIS FIRST CASE, WE

533
00:18:54,040 --> 00:18:56,080
ADDED THE SNAKE VENOM TOXIN I

534
00:18:56,080 --> 00:18:56,480
MENTIONED.

535
00:18:56,480 --> 00:18:57,640
WE THOUGHT AT THE BEGINNING WE

536
00:18:57,640 --> 00:19:01,920
WERE GOING TO NEED SOME KIND OF

537
00:19:01,920 --> 00:19:02,920
BIG ASYMMETRIC MOLECULE STICKING

538
00:19:02,920 --> 00:19:04,240
OUT OF THE SIDE OF THE RECEPTOR

539
00:19:04,240 --> 00:19:05,800
THAT WOULD ALLOW US TO ALIGN

540
00:19:05,800 --> 00:19:10,520
PARTICLES IN 3 DIMENSIONS, SO IN

541
00:19:10,520 --> 00:19:11,720
CRYOEM WE'RE AVERAGING HUNDREDS

542
00:19:11,720 --> 00:19:13,360
OF THOUSANDS OF MILLIONS OF

543
00:19:13,360 --> 00:19:14,640
PARTICLES FROM DIFFERENT

544
00:19:14,640 --> 00:19:18,080
ORIENTATIONS TO GENERATE A 3D

545
00:19:18,080 --> 00:19:19,680
RECONSTRUCTION, THESE RECEPTORS

546
00:19:19,680 --> 00:19:21,120
CEMET RICK OR PSEUDOSYMMETRIC

547
00:19:21,120 --> 00:19:22,840
AROUND THE 5 FOLD ACCESS AND,A

548
00:19:22,840 --> 00:19:24,720
LIENING PARTICLES STARTS USING

549
00:19:24,720 --> 00:19:26,240
ONLY LOW RESOLUTION INFORMATION

550
00:19:26,240 --> 00:19:28,320
SO YOU'RE LOOKING FOR BIG

551
00:19:28,320 --> 00:19:30,240
FEATURES AND AT LOW RESOLUTION,

552
00:19:30,240 --> 00:19:31,480
YOU CAN'T TELL, WE WOULD BT

553
00:19:31,480 --> 00:19:33,160
THINK AN ALPHA FROM A BETA FROM

554
00:19:33,160 --> 00:19:34,720
A GATE KEEPER AMIA FROM A DELTA

555
00:19:34,720 --> 00:19:36,360
SUBUNIT AND IF YOU SUPER IMPOSE

556
00:19:36,360 --> 00:19:37,680
THOSE ON TOP OF EACH OTHER AND

557
00:19:37,680 --> 00:19:39,080
FIND A HIGH RESOLUTION, YOU WILL

558
00:19:39,080 --> 00:19:41,520
BLUR OUT BECAUSE YOU WILL SUPER

559
00:19:41,520 --> 00:19:46,560
IMPOSE ALPHAS AND SO WE ADD BUNG

560
00:19:46,560 --> 00:19:47,760
AROTOXIN SO WE THOUSAND DOLLAR

561
00:19:47,760 --> 00:19:49,440
IT WOULD GIVE IT WINGS TO,A

562
00:19:49,440 --> 00:19:50,200
LIEN.

563
00:19:50,200 --> 00:19:51,680
THEN WE COLLECTED CRYOEM DATA

564
00:19:51,680 --> 00:19:54,000
AND WE SEE THESE DIMERS AND

565
00:19:54,000 --> 00:19:55,600
PENTAMERS AND HERE'S A SIDE

566
00:19:55,600 --> 00:19:56,720
VIEW, WHERE THEY'RE PARALLEL TO

567
00:19:56,720 --> 00:19:58,440
EACH OTHER MAYBE IN 1 LARGE NANO

568
00:19:58,440 --> 00:19:59,640
DISK AND MAYBE YOU CAN SEE

569
00:19:59,640 --> 00:20:01,400
BETWEEN THESE EXTRA CELLULAR

570
00:20:01,400 --> 00:20:03,040
DOMAINS, THERE ARE THESE WINGS

571
00:20:03,040 --> 00:20:04,400
STICKING OUT, THAT'S THE

572
00:20:04,400 --> 00:20:05,520
NEUROTOXIN, THIS IS THE FIRST

573
00:20:05,520 --> 00:20:07,480
DATA SET WE COLLECTED ON THESE

574
00:20:07,480 --> 00:20:09,760
AND WE COULD SEE THESE FEATURES,

575
00:20:09,760 --> 00:20:11,320
VERY EXCITING BUT WE HAVE THESE

576
00:20:11,320 --> 00:20:12,640
DIMERS AND PENTINE REGIMEN MERS

577
00:20:12,640 --> 00:20:14,120
AND THEY ADOPT DIFFERENT

578
00:20:14,120 --> 00:20:14,760
ORIENTATIONS RELATIVE TO EACH

579
00:20:14,760 --> 00:20:16,680
OTHER AND WHICH WOULD BE A

580
00:20:16,680 --> 00:20:18,920
PROBLEM ARE FOR RECONSTRUCTING A

581
00:20:18,920 --> 00:20:20,080
3D STRUCTURE.

582
00:20:20,080 --> 00:20:21,960
SO WE TRIED SOME REDUCING

583
00:20:21,960 --> 00:20:23,920
REAGENTS AND PEOPLE SHOWED 30

584
00:20:23,920 --> 00:20:25,400
YEARS AGO, YOU COULD ADD THE

585
00:20:25,400 --> 00:20:26,520
ETHAN OLDER PEOPLE AND REDUCE

586
00:20:26,520 --> 00:20:28,600
THESE AND FUNCTION WAS

587
00:20:28,600 --> 00:20:29,240
IDENTICAL, YOU COULD RECONSITUTE

588
00:20:29,240 --> 00:20:30,480
THEM AND WE FOUND THE SAME

589
00:20:30,480 --> 00:20:31,080
THING.

590
00:20:31,080 --> 00:20:33,120
SO WE ADD BME AND WE RUN THE

591
00:20:33,120 --> 00:20:35,160
FILTRATION, TO CLEAN IT UP AND

592
00:20:35,160 --> 00:20:37,080
WE SHIP THE DIMER OVER TO THE

593
00:20:37,080 --> 00:20:38,720
MONITOR MERAND THAT'S WHAT WE US

594
00:20:38,720 --> 00:20:40,680
THEN FOR STRUCTURAL BIOLOGY.

595
00:20:40,680 --> 00:20:42,280
>>ALL RIGHT, SO HERE'S AN

596
00:20:42,280 --> 00:20:43,680
EXAMPLE OF THE PATHWAY FOR

597
00:20:43,680 --> 00:20:45,280
PROCESSING 1 OF THESE DATA SETS

598
00:20:45,280 --> 00:20:47,920
SO WE COLLECT THOUSANDS OF

599
00:20:47,920 --> 00:20:49,000
ELECTRON MICROGAFFS, I SECOND

600
00:20:49,000 --> 00:20:50,360
QUARTERLED A COUPLE OF THE

601
00:20:50,360 --> 00:20:51,960
RECEPTORS UP HERE THAT ARE

602
00:20:51,960 --> 00:20:53,960
SINGLE PENTINE REGIMEN MERS, NOT

603
00:20:53,960 --> 00:20:55,680
DIMERS OR PENTINE REGIMEN MERS,

604
00:20:55,680 --> 00:20:57,080
2 D CLASSIFICATION TO GET A DATA

605
00:20:57,080 --> 00:20:58,400
SET AND GET A SENSE OF DATA

606
00:20:58,400 --> 00:20:59,120
QUALITY.

607
00:20:59,120 --> 00:21:00,280
IN THE UPPER LEFT HAND KARNER WE

608
00:21:00,280 --> 00:21:02,680
HAVE THE EXTRA CELLULAR DOMAIN,

609
00:21:02,680 --> 00:21:03,920
TRANSMEMBRANE DOMAIN, WRAPPED IN

610
00:21:03,920 --> 00:21:04,880
THE SCAFFOLD AND NOTHING

611
00:21:04,880 --> 00:21:07,520
STICKING OUT OF THE BOTTOM.

612
00:21:07,520 --> 00:21:08,360
CONTRAST THAT WITH THIS 1 HERE

613
00:21:08,360 --> 00:21:12,160
AND YOU CAN SEE NICE DENSITY FOR

614
00:21:12,160 --> 00:21:13,080
THE INTRACELLULAR DOMAIN AND

615
00:21:13,080 --> 00:21:14,960
WHEN WE MOVE ON TO 3D

616
00:21:14,960 --> 00:21:16,040
CLASSIFICATION, WE SEE SOMETHING

617
00:21:16,040 --> 00:21:17,240
SIMILAR WHERE HALF THE PARTICLES

618
00:21:17,240 --> 00:21:19,080
ARE LACKING THE IMPOSSIBLE TO

619
00:21:19,080 --> 00:21:20,040
BUILD RACELLULAR DOMAIN,

620
00:21:20,040 --> 00:21:20,720
PROBABLY DAMAGED FROM

621
00:21:20,720 --> 00:21:21,760
INTERACTING WITH THE AIR WATER

622
00:21:21,760 --> 00:21:22,840
INTERFACE, SOMETHING LIKE THAT,

623
00:21:22,840 --> 00:21:24,400
THAT'S A GUESS, SO WE THROW OUT

624
00:21:24,400 --> 00:21:27,000
THOSE PARTICLES THAT ARE IN THAT

625
00:21:27,000 --> 00:21:29,920
CLASS BECAUSE WE ONLY WANT

626
00:21:29,920 --> 00:21:32,120
INTACT RECEPTORS AND THEN WE

627
00:21:32,120 --> 00:21:33,040
REFINED HIGH RUZ LIEWGZ AND WE

628
00:21:33,040 --> 00:21:35,200
SEE THAT THE RESOLUTION'S FAIRLY

629
00:21:35,200 --> 00:21:39,240
ISOTROPIC THROUGH THE WHOLE

630
00:21:39,240 --> 00:21:39,480
RECEPTOR.

631
00:21:39,480 --> 00:21:40,480
REALLY IMPRESSIVELY BEAUTIFUL

632
00:21:40,480 --> 00:21:41,360
STRUCTURES COMPARED TO OTHER

633
00:21:41,360 --> 00:21:45,760
PROTEINS WE'RE WORKING WITH.

634
00:21:45,760 --> 00:21:46,240
ALL RIGHT.

635
00:21:46,240 --> 00:21:48,560
SO THIS IS THE APO STRUCTURE IN

636
00:21:48,560 --> 00:21:51,080
THE ABSENCE AND PRESENCE OF

637
00:21:51,080 --> 00:21:55,240
DOPED IN CHOLESTEROL.

638
00:21:55,240 --> 00:21:58,560
SO THERE'S A LOT OF INFORMATION

639
00:21:58,560 --> 00:22:00,640
IN THIS AREA, ON LIPID FUNCTION

640
00:22:00,640 --> 00:22:02,400
AND ESPECIALLY CHOLESTEROL AND

641
00:22:02,400 --> 00:22:05,400
IN THE TORPEDO ELECTRIC RAY,

642
00:22:05,400 --> 00:22:07,600
IT'S LIKE 40% CHOLESTEROL, IT'S

643
00:22:07,600 --> 00:22:08,560
SUPER ABUNDANT IN OUR BRAINS,

644
00:22:08,560 --> 00:22:10,440
AND WE WANT TO LOOK AT

645
00:22:10,440 --> 00:22:12,360
CHOLESTEROL BINDING SEAT SITES

646
00:22:12,360 --> 00:22:13,520
SO WE COLLECTED AND WE CAN SEE

647
00:22:13,520 --> 00:22:16,480
THAT SOME OF THESE RED PEEKS

648
00:22:16,480 --> 00:22:18,080
GET--APPEAR WHEN YOU ADD

649
00:22:18,080 --> 00:22:19,480
CHOLESTEROL AND SOME SIMPLY GET

650
00:22:19,480 --> 00:22:20,480
STRONGER SOPHISTICATEDY WE'RE

651
00:22:20,480 --> 00:22:22,920
ABLE TO IDENTIFY OR ASSIGN LOWER

652
00:22:22,920 --> 00:22:25,520
AND HIGHER AFFINITY CHOLESTEROL

653
00:22:25,520 --> 00:22:25,720
SITES.

654
00:22:25,720 --> 00:22:27,360
SO THIS IS THE EXTRA CELLULAR

655
00:22:27,360 --> 00:22:28,280
DOMAIN, THESE THERAPIST IS

656
00:22:28,280 --> 00:22:30,360
GLYCANS THAT COME OFF AND IN THE

657
00:22:30,360 --> 00:22:31,640
INTRACELLULAR DOMAIN AND THEN

658
00:22:31,640 --> 00:22:33,720
THIS IS THE TRANSMEMBRANE DOMAIN

659
00:22:33,720 --> 00:22:36,120
IN THE SCAFFOLD,ER SO HERE'S THE

660
00:22:36,120 --> 00:22:40,000
ARK RANGEMENT OF SUBUNITS

661
00:22:40,000 --> 00:22:41,440
ALREADY WELL DELINEATED BY OTHER

662
00:22:41,440 --> 00:22:42,640
PEOPLE AND THEY HAVE THE

663
00:22:42,640 --> 00:22:44,720
LEFT-HAND SIDE OF THE

664
00:22:44,720 --> 00:22:45,360
NEUROTRANSMITTER BINDING POCKET

665
00:22:45,360 --> 00:22:47,440
AND THEN GAMMA AND DELTA

666
00:22:47,440 --> 00:22:49,680
SUBUNITS MAKE WHAT WE CALL THE

667
00:22:49,680 --> 00:22:51,480
COMPLIMENTARY SIDES OF THESE

668
00:22:51,480 --> 00:22:53,120
NEUROTRANSMITTER BINDING POCKETS

669
00:22:53,120 --> 00:22:54,200
SO THAT'S WHERE

670
00:22:54,200 --> 00:22:54,720
NEUROTRANSPOLITTERS BIND.

671
00:22:54,720 --> 00:22:56,800
I WILL SHOW YOU WHAT AN ALPHA

672
00:22:56,800 --> 00:22:57,960
AND NONALPHA SUBUNIT LOOK LIKE

673
00:22:57,960 --> 00:23:00,920
BECAUSE IT TURNS OUT WE DIDN'T

674
00:23:00,920 --> 00:23:03,960
NEED ALPHA BUNKINGAR O TOXIN TO

675
00:23:03,960 --> 00:23:04,920
PROPERLY REGISTER THE ALIGNMENT

676
00:23:04,920 --> 00:23:05,760
OF THESE PARTICLES.

677
00:23:05,760 --> 00:23:07,480
SO HERE'S AN ALPHA SUBUNIT, 1 OF

678
00:23:07,480 --> 00:23:09,360
THE 2, SO EXTRA CELLULAR

679
00:23:09,360 --> 00:23:11,200
DOMAININNA, LOOP CALLED LOOP C

680
00:23:11,200 --> 00:23:12,640
WHICH IS SHOWN HERE IN THIS SIDE

681
00:23:12,640 --> 00:23:14,880
VIEW, SO IT CAPS THE

682
00:23:14,880 --> 00:23:15,600
NEUROTRANSMITTER BINDING POCKET,

683
00:23:15,600 --> 00:23:19,840
AND FORMS A LOT OF INTERACTIONS

684
00:23:19,840 --> 00:23:21,480
WITH AGONISTS, LIKE CHOLINE, THE

685
00:23:21,480 --> 00:23:24,200
LOOP THAT GIVES THE FAMILY ITS

686
00:23:24,200 --> 00:23:25,280
NAME CONNECTS THE

687
00:23:25,280 --> 00:23:26,000
NEUROTRANSBINDING SITE, IT SITS

688
00:23:26,000 --> 00:23:28,120
LIKE A BALL IN A SOCKET SO WHEN

689
00:23:28,120 --> 00:23:29,760
DMIEWR O TRANSMITTERS BIND, THEY

690
00:23:29,760 --> 00:23:31,160
CAN PULLOT CONFIRMATION OF THE

691
00:23:31,160 --> 00:23:33,680
TMD OPEN GATES AND ALLOW IONS TO

692
00:23:33,680 --> 00:23:35,240
GO THROUGH.

693
00:23:35,240 --> 00:23:37,880
THE 4 TRANSMEMBRANE SPANNING

694
00:23:37,880 --> 00:23:39,080
ALPHA HELIXES AND INTRACELLULAR

695
00:23:39,080 --> 00:23:41,560
DOMAIN, SO I WILL SUPER IMPOSE A

696
00:23:41,560 --> 00:23:42,480
NONALPHA SUBHIEWNT ON HERE AND

697
00:23:42,480 --> 00:23:43,760
WE CAN SEE WHAT THE DIFFERENCES

698
00:23:43,760 --> 00:23:46,600
ARE AS WELL AS SIMILARITIES SO

699
00:23:46,600 --> 00:23:47,320
HERE'S ALPHA VERSUS DELTA

700
00:23:47,320 --> 00:23:48,000
SUBUNIT.

701
00:23:48,000 --> 00:23:49,640
SO I HOPE YOU CAN APPRECIATE

702
00:23:49,640 --> 00:23:52,560
THAT THE CORE OF ALL 3 OF THESE

703
00:23:52,560 --> 00:23:54,280
DOMAINS ALIGNS VERY WELL.

704
00:23:54,280 --> 00:23:55,760
WHERE ARE THEY DIFFERENT?

705
00:23:55,760 --> 00:23:57,280
THEY'RE DIFFERENT IN THE C-TERM

706
00:23:57,280 --> 00:23:59,480
NIGH AND IN THE LOOP F AND ALSO

707
00:23:59,480 --> 00:24:01,280
LOOP C IS DIFFERENT BUT IT'S NOT

708
00:24:01,280 --> 00:24:05,320
SHOWN VERY WELL HERE.

709
00:24:05,320 --> 00:24:08,480
SO APPARENTLY THE C-TERM INI AND

710
00:24:08,480 --> 00:24:10,520
THE F, WHICH ARE FOUND IN THE

711
00:24:10,520 --> 00:24:13,040
DAM ADELTA AND BETA SUBUNITS,

712
00:24:13,040 --> 00:24:14,560
ARE ENOUGH IN SYMMETRY, CAN YOU

713
00:24:14,560 --> 00:24:16,440
SEE THEM STICKING OUT TO

714
00:24:16,440 --> 00:24:18,200
PROPERLY,A LIEN PARTICLES SO

715
00:24:18,200 --> 00:24:20,160
THIS FORMS THE BACK SIDE OF THE

716
00:24:20,160 --> 00:24:24,480
BINDING POCKET ON THESE SUBUNITS

717
00:24:24,480 --> 00:24:25,520
AND THE C-TERNIMI EXPEND UP

718
00:24:25,520 --> 00:24:28,040
WHICH IS NOTTINE IN THE SUBUNITS

719
00:24:28,040 --> 00:24:31,480
AND HUNDRED BEEN SEEN IN THE

720
00:24:31,480 --> 00:24:31,880
STRUCTURES BEFORE.

721
00:24:31,880 --> 00:24:33,520
ALL RIGHT SO 1 OF THE BIG

722
00:24:33,520 --> 00:24:35,880
QUESTIONS FROM THE FIELD IS

723
00:24:35,880 --> 00:24:37,440
GAINING MECHANISM, HOW DOES THIS

724
00:24:37,440 --> 00:24:38,640
TRANSMITTER OPEN AND CLOSE HE'S

725
00:24:38,640 --> 00:24:40,280
CHANNELS AND WHAT IS THE GATING

726
00:24:40,280 --> 00:24:42,400
CYCLE, SO WE HAVE CHANNELS IN

727
00:24:42,400 --> 00:24:44,800
ARRESTING ESTATE, YOU APPLY

728
00:24:44,800 --> 00:24:46,560
AGONIST LIKE ASTEOCHOLLINE, THEY

729
00:24:46,560 --> 00:24:48,480
BRIEFLY ACTIVATE AND IN THE

730
00:24:48,480 --> 00:24:50,000
SUSTAINED PRESENCE OF AGONIST,

731
00:24:50,000 --> 00:24:52,240
THEY DESENSITIZE AND NEARLYY ALL

732
00:24:52,240 --> 00:24:55,800
ION CHANNELS DO THIS.

733
00:24:55,800 --> 00:24:56,840
WHEN NEUROTRANSMITTER

734
00:24:56,840 --> 00:24:58,240
CONCENTRATION DROPS THEY CAN DO

735
00:24:58,240 --> 00:24:59,400
THIS AND CONVERT BACK TO A

736
00:24:59,400 --> 00:25:00,440
RESTING STATE.

737
00:25:00,440 --> 00:25:03,680
SO WE HAVE AN APO RESTING ESTATE

738
00:25:03,680 --> 00:25:04,560
STRUCTURE AND AGONIST BOUND

739
00:25:04,560 --> 00:25:06,480
TRUCTURE, WE DO NOT HAVE AN

740
00:25:06,480 --> 00:25:07,480
ACTIVATED STATE STRUCTURE, I

741
00:25:07,480 --> 00:25:09,400
WOULD HAVE LOVED TO SHOW YOU AN

742
00:25:09,400 --> 00:25:10,040
ACTIVATED STRUCTURE TODAY,

743
00:25:10,040 --> 00:25:11,520
THERE'S A LOT OF DEBATE ABOUT,

744
00:25:11,520 --> 00:25:14,120
YOU KNOW WE HAVE SOME ACTIVATED

745
00:25:14,120 --> 00:25:15,320
STATE STRUCTURES OF HOMOPENTINE

746
00:25:15,320 --> 00:25:16,760
REGIMEN MERS OF GLUE MARIOUS

747
00:25:16,760 --> 00:25:18,960
SEEN RECEPTORS OF THE SUBTYPE

748
00:25:18,960 --> 00:25:21,640
FROM OUR LABS, SERIES POINTSA

749
00:25:21,640 --> 00:25:23,120
TONIC RECEPTORS, AND

750
00:25:23,120 --> 00:25:25,200
[INDISCERNIBLE], BUT WE LACK ANY

751
00:25:25,200 --> 00:25:25,800
HETEROPENTINE REGIMEN

752
00:25:25,800 --> 00:25:27,280
MERSTRUCTURES AND WHETHER

753
00:25:27,280 --> 00:25:28,720
THEY'RE FAIRLY SYMMETRIC OR

754
00:25:28,720 --> 00:25:30,000
ASYMMETRIC, PEOPLE ARE ARGUING

755
00:25:30,000 --> 00:25:31,080
ABOUT, SO WE WOULD LIKE TO SEE

756
00:25:31,080 --> 00:25:33,360
THAT BUT WE DON'T HAVE IT, I AND

757
00:25:33,360 --> 00:25:34,520
I HAVED WHYS ABOUT HOW TO GETD

758
00:25:34,520 --> 00:25:36,520
IT AND I WILL TALK ABOUT IT THEA

759
00:25:36,520 --> 00:25:38,640
THE VERY END BUT I CAN COMPARE

760
00:25:38,640 --> 00:25:41,720
AN RESTING STRAIGHT STRUCTURE

761
00:25:41,720 --> 00:25:49,640
ORAL AGONIST BOUND DESENSITIZED

762
00:25:49,640 --> 00:25:49,920
STRUCTURE.

763
00:25:49,920 --> 00:25:51,760
SO THIS IS THE LARGE VESTIBULE,

764
00:25:51,760 --> 00:26:01,000
THESE SPHERES ARE JUST TO GIVE

765
00:26:01,000 --> 00:26:11,480
YOUR EYES A SHAPE--SO WE CAN

766
00:26:12,080 --> 00:26:13,400
ZOOM ON THE CONSTRIBLGHTED PART

767
00:26:13,400 --> 00:26:14,800
HERE THROUGH THE TRANSMEMBRANE

768
00:26:14,800 --> 00:26:17,680
SPANNING PORG OF THE RECEPTOR,OT

769
00:26:17,680 --> 00:26:20,240
LEFT SIDE ARE DIAMETERS FOR SOME

770
00:26:20,240 --> 00:26:22,480
OF THESE KEY POINTS ALONG THE

771
00:26:22,480 --> 00:26:23,600
PERMEATION PATHWAY OR AMINO

772
00:26:23,600 --> 00:26:25,280
ACIDS THAT LINE THE CHANNEL,

773
00:26:25,280 --> 00:26:35,160
SHOWING THE ALPHA SUBUNITS ON

774
00:26:35,160 --> 00:26:37,160
OPPOSITE SIDE HERE 22 TYPE FOR

775
00:26:37,160 --> 00:26:38,440
HYDRATED IONS TO GO THROUGH AND

776
00:26:38,440 --> 00:26:40,680
WE LOOK AT DESENSITIZED STATE IN

777
00:26:40,680 --> 00:26:43,160
COMPARISON WHAT WE SEE IS A

778
00:26:43,160 --> 00:26:46,880
WIDENING OF THE TOP HALF THE

779
00:26:46,880 --> 00:26:48,480
COURSE, THE TIGHT HALF IS NEAR

780
00:26:48,480 --> 00:26:50,920
THE TOP AND IT'S 2 AND HALF

781
00:26:50,920 --> 00:26:52,480
ANGSTROMS IN DIAMETER AND THAT

782
00:26:52,480 --> 00:26:54,920
OPENS UP TO 8-ANGSTROMS IN

783
00:26:54,920 --> 00:26:55,200
DIAMETER.

784
00:26:55,200 --> 00:26:57,240
SO CHANGES IN THE EXTRA CELLULAR

785
00:26:57,240 --> 00:27:00,000
DOMAIN PULL OPEN THE TOPS OF THE

786
00:27:00,000 --> 00:27:00,760
HELIXES DURING ACTIVATION AND WE

787
00:27:00,760 --> 00:27:02,360
THINK THAT THE BOTTOM CLOSES

788
00:27:02,360 --> 00:27:03,880
BECAUSE THE BOTTOM IS ABOUT AS

789
00:27:03,880 --> 00:27:06,240
TIGHTLY CLOSED IN THE

790
00:27:06,240 --> 00:27:08,000
DESENSITIZED AND RESTING STATES.

791
00:27:08,000 --> 00:27:10,240
SO HOW DO WE,A SIGN

792
00:27:10,240 --> 00:27:11,360
CONFIRMATIONAL STATES OR

793
00:27:11,360 --> 00:27:12,440
PHYSIOLOGICAL STATES TO THESE

794
00:27:12,440 --> 00:27:13,360
STATIC STRUCTURES WE'RE LOOKING

795
00:27:13,360 --> 00:27:13,720
AT.

796
00:27:13,720 --> 00:27:15,120
THIS IS AN UNANSWERED QUESTION

797
00:27:15,120 --> 00:27:19,600
IN THE FIELD, HOW TO DO THIS

798
00:27:19,600 --> 00:27:20,320
KIND OF RIGOROUSLY.

799
00:27:20,320 --> 00:27:21,280
WE CAN DO THAT WITH THE

800
00:27:21,280 --> 00:27:22,520
STRUCTURE WE SEE THAT WHILE WE

801
00:27:22,520 --> 00:27:24,440
THINK IT SHOULD BE DESENSITIZED

802
00:27:24,440 --> 00:27:26,560
BECAUSE AGONIST IS BOUND AND

803
00:27:26,560 --> 00:27:27,240
IT'S EQUILIBRIUM, THERE WILL BE

804
00:27:27,240 --> 00:27:30,240
A BIT OF LEAK OF IONS IN MD

805
00:27:30,240 --> 00:27:30,560
SIMULATIONS.

806
00:27:30,560 --> 00:27:32,120
DOES THAT MATCH THE PREDICTED

807
00:27:32,120 --> 00:27:33,520
SINGLE CHANNEL CONDUCT ABTS,

808
00:27:33,520 --> 00:27:35,520
WELL MD IS NOT VERY GOOD AT

809
00:27:35,520 --> 00:27:37,800
MATCHING SINGLES CHANNEL CONDUCT

810
00:27:37,800 --> 00:27:38,960
ANTS FROM ELECTROPHYSIOLOGY

811
00:27:38,960 --> 00:27:41,080
EXPERIMENTS SO WHAT DO YOU SAY,

812
00:27:41,080 --> 00:27:43,440
IS THIS CONDUCTING,

813
00:27:43,440 --> 00:27:44,040
NONCONDUCTING INTERMEDIATE SO

814
00:27:44,040 --> 00:27:45,560
IT'S HELPFUL TO GO BACK TO THE

815
00:27:45,560 --> 00:27:46,840
CLASSIC STUDIES ON HOW BIG ARE

816
00:27:46,840 --> 00:27:48,520
THE IONS THAT CAN GET THROUGH

817
00:27:48,520 --> 00:27:50,360
THE ACTIVATED STATES OF THESE

818
00:27:50,360 --> 00:27:50,720
CHANNELS.

819
00:27:50,720 --> 00:27:52,960
THIS IS MY FAVORITE FOR THE NICK

820
00:27:52,960 --> 00:27:55,400
O THENNIC RECEPTOR, SO THIS IS

821
00:27:55,400 --> 00:27:56,280
BRITTLE'S GROUP IN 1980 WHERE

822
00:27:56,280 --> 00:27:58,920
MAY PUT THROUGH A SERIES OF CAT

823
00:27:58,920 --> 00:28:00,480
IONS MANY ORGANIC CAT IONS

824
00:28:00,480 --> 00:28:01,680
THROUGH THESE TYPES OF ION

825
00:28:01,680 --> 00:28:03,080
CHANNELS TO SAY HOW BIG SHOULD

826
00:28:03,080 --> 00:28:08,040
THE CHANNEL BE AND MAN, THIS IS

827
00:28:08,040 --> 00:28:10,200
SUCH SUCH BEAUTIFUL WORK, SO

828
00:28:10,200 --> 00:28:11,880
WHATEVER, ALMOST 20 YEARS BEFORE

829
00:28:11,880 --> 00:28:15,120
ROD Mc KINON GO THE STRUCTURE

830
00:28:15,120 --> 00:28:16,280
OF KCSA, POTASSIUM WAS SHOWING

831
00:28:16,280 --> 00:28:22,840
IT WOULD GO THROUGH AS A

832
00:28:22,840 --> 00:28:23,480
DECARBONATED CAT ION.

833
00:28:23,480 --> 00:28:33,960
SO IT CAN BE SELECTIVE THIS IS

834
00:28:38,240 --> 00:28:39,680
TOTALLY DIFFERENT ANIMAL, YOU

835
00:28:39,680 --> 00:28:41,400
COULD DRIVE A TRAIN THROUGH THIS

836
00:28:41,400 --> 00:28:41,920
ION CHANNEL.

837
00:28:41,920 --> 00:28:43,760
IT'S NOT TRYING TO SELECT AMONG

838
00:28:43,760 --> 00:28:45,440
DIFFERENT CAT IONS IT'S TRYING

839
00:28:45,440 --> 00:28:52,440
TO LET THROUGH ANY CAT IONS

840
00:28:52,440 --> 00:28:53,520
MUSCLE CONSTRUCTION AND HAVE IT

841
00:28:53,520 --> 00:28:54,400
WORK EVERY TIME.

842
00:28:54,400 --> 00:28:55,440
IT'S VERY DIFFERENT SO BASED ON

843
00:28:55,440 --> 00:28:57,920
THIS KIND OF STUDY, WE WOULD

844
00:28:57,920 --> 00:29:00,280
CONCLUDE THAT IONS, SODIUM,

845
00:29:00,280 --> 00:29:01,080
POTASSIUM, CALCJUM WHATEVER,

846
00:29:01,080 --> 00:29:04,480
WOULD BE DOING THAT AS A

847
00:29:04,480 --> 00:29:04,880
HYDRATED SPECIES.

848
00:29:04,880 --> 00:29:07,160
SEVEN AND A HALF ANGSTROMS ON

849
00:29:07,160 --> 00:29:08,720
THE DIAGONAL, IN DIAMETER SO

850
00:29:08,720 --> 00:29:10,320
WHAT DID WE SEE, WE SAW

851
00:29:10,320 --> 00:29:12,200
CONSTRUCTION OF 4 AND HALF

852
00:29:12,200 --> 00:29:13,400
ANGSTROMS IN THIS DESENSITIZED

853
00:29:13,400 --> 00:29:14,720
STATE SO BASED ON THAT I WOULD

854
00:29:14,720 --> 00:29:18,280
SAY THIS IS A REASONABLE

855
00:29:18,280 --> 00:29:19,440
ESTIMATION FOR A DESENSITIZED

856
00:29:19,440 --> 00:29:20,080
STATE STRUCTURE BECAUSE IT'S

857
00:29:20,080 --> 00:29:21,920
WEIRD THAT THE CONSTRUCTION IS 4

858
00:29:21,920 --> 00:29:24,120
AND HALF RESTRICTIONS IN

859
00:29:24,120 --> 00:29:24,400
DIAMETER.

860
00:29:24,400 --> 00:29:25,120
SODIUM'S SMALLER THAT THAN AND

861
00:29:25,120 --> 00:29:31,200
THIS IS A POLAR CONSTRUCTION,

862
00:29:31,200 --> 00:29:32,800
THE AN ION HAVE PHOTO RECEPTORS

863
00:29:32,800 --> 00:29:36,640
AT THE BOTTOM AND IT'S EASIER TO

864
00:29:36,640 --> 00:29:37,600
THINK ABOUT HYDROPHOBIC WHERE

865
00:29:37,600 --> 00:29:39,440
THEY CAN STICK TOGETHER, WATER

866
00:29:39,440 --> 00:29:41,480
PONENT BE HAPPY THERE, THESE ARE

867
00:29:41,480 --> 00:29:43,000
POLAR RESIDUES MAKING IT POLAR

868
00:29:43,000 --> 00:29:43,200
GATE.

869
00:29:43,200 --> 00:29:44,280
SO THERE'S STILL ARGUMENT ABOUT

870
00:29:44,280 --> 00:29:45,520
WHAT ARE THESE GOING TO BE

871
00:29:45,520 --> 00:29:47,440
LEAKY, WHAT IS A REAL OPEN STATE

872
00:29:47,440 --> 00:29:48,920
LOOK LIKE ON THE CAT ION

873
00:29:48,920 --> 00:29:52,200
SELECTIVE SIDE OF THE FAMILY.

874
00:29:52,200 --> 00:29:52,800
SO, UNSOLVED PROBLEM.

875
00:29:52,800 --> 00:29:56,440
WE WILL SWITCH FROM CHANNEL

876
00:29:56,440 --> 00:29:57,640
BIOPHYSICS TO PHARMACOLOGY AND

877
00:29:57,640 --> 00:30:02,200
WE WILL CONTRAST THESE 2 NATURAL

878
00:30:02,200 --> 00:30:02,440
PRODUCTS.

879
00:30:02,440 --> 00:30:05,800
SO ALPHA BUNG AROTOXIN, COMPETES

880
00:30:05,800 --> 00:30:08,320
WITH AFTIO ALCOHOLIN AND BINDS

881
00:30:08,320 --> 00:30:16,000
IRREVERSIBLY, THE OFF RATE'S

882
00:30:16,000 --> 00:30:16,440
VERY SLOW.

883
00:30:16,440 --> 00:30:19,200
IT COMES FROM A BLAPT, IT ALSO

884
00:30:19,200 --> 00:30:20,280
COMPETES WITH AFTIO ALCOHOLIN

885
00:30:20,280 --> 00:30:23,160
BUT IT HAS COMPLEX ACTIVITY SO

886
00:30:23,160 --> 00:30:24,600
IN EMBRYONIC NICOTINIC

887
00:30:24,600 --> 00:30:33,440
RECEPTORS, THE 1S THAT HAVE THE

888
00:30:33,440 --> 00:30:34,040
DELTA SUBUNIT,

889
00:30:34,040 --> 00:30:35,440
THEY--[INDISCERNIBLE] IS A

890
00:30:35,440 --> 00:30:38,000
CHANNEL OPENING BEFORE YOU GET

891
00:30:38,000 --> 00:30:38,280
PARALYSIS.

892
00:30:38,280 --> 00:30:39,680
SO, LOOK AT THE STRUCTURE WITH

893
00:30:39,680 --> 00:30:41,160
THE BUNG AROTOXINAR O TOXIN,

894
00:30:41,160 --> 00:30:42,000
THIS IS THE FIRST STRUCTURE WE

895
00:30:42,000 --> 00:30:43,640
GOT ACCIDENT I MENTIONED WE TRY

896
00:30:43,640 --> 00:30:45,720
TO USE IT TO,A LIEN PARTICLES

897
00:30:45,720 --> 00:30:47,040
WHICH DID WORK AND RATHER THAN

898
00:30:47,040 --> 00:30:48,520
SHOWING YOU ALL THESE

899
00:30:48,520 --> 00:30:50,160
CONFIRMATIONS OF THE PERMEATION

900
00:30:50,160 --> 00:30:51,240
PATHWAY, I WILL SUMMARIZE THE

901
00:30:51,240 --> 00:30:53,000
DATA IN GRAPHS LIKE THIS SO WE

902
00:30:53,000 --> 00:30:56,160
HAVE ON THE Y-AXIS, PORE, THE

903
00:30:56,160 --> 00:30:58,080
LONG AX INCREASE IN BODY TO THE

904
00:30:58,080 --> 00:30:59,480
CHANNEL VERSUS PORE DIAMETER SO

905
00:30:59,480 --> 00:31:03,160
IN RESTING STATE WE CAN SEE THAT

906
00:31:03,160 --> 00:31:05,000
APO STRUCTURE I SHOWED YOU

907
00:31:05,000 --> 00:31:07,320
BEFORE, THE TOP OF THE POUR IS

908
00:31:07,320 --> 00:31:08,640
TIGHTLY CLOSED, VERSUS THE

909
00:31:08,640 --> 00:31:09,440
DESENSITIZED STATE THAT OPENING

910
00:31:09,440 --> 00:31:11,880
UP AT THE TOP OF THE PORE,

911
00:31:11,880 --> 00:31:13,440
THAT'S WHAT I'M SHOWING IN THIS

912
00:31:13,440 --> 00:31:22,840
GRAPH, WHAT DOES THIS LOOK LIKE

913
00:31:22,840 --> 00:31:26,240
IN BUNG AROTOXIN BIND OR DO?

914
00:31:26,240 --> 00:31:27,840
I WILL NOT SHOW YOU ALL THE

915
00:31:27,840 --> 00:31:29,160
DETAILS FOR ALL THEE LIGANDS.

916
00:31:29,160 --> 00:31:30,680
I KNOW MOST OF YOU DON'T CARE

917
00:31:30,680 --> 00:31:32,360
ABOUT THIS UNLESS IT'S YOUR

918
00:31:32,360 --> 00:31:33,040
PROTEIN OF INTEREST.

919
00:31:33,040 --> 00:31:35,240
I FEEL THE SAME BUT I THINK THIS

920
00:31:35,240 --> 00:31:40,640
IS AN INTERESTING EXAMPLE.

921
00:31:40,640 --> 00:31:42,240
[LAUGHTER]

922
00:31:42,240 --> 00:31:42,640
IT'S TRUE, RIGHT?

923
00:31:42,640 --> 00:31:45,680
IT'S GOT 3 FINGERS, 1, 2, 3, THE

924
00:31:45,680 --> 00:31:47,320
SECOND FINGER INSERTS DEEPLY

925
00:31:47,320 --> 00:31:48,480
INTO THE SUBUNIT INTERFACE AND

926
00:31:48,480 --> 00:31:51,920
IT BRINGS ALONG HAPPENING THIS

927
00:31:51,920 --> 00:31:54,280
R-GENNINE RESIDUE AND IT THE

928
00:31:54,280 --> 00:31:57,240
AGONIST INCLUDES BASIC NITROGEN,

929
00:31:57,240 --> 00:31:57,960
FORMAL POSITIVE CHARGE,

930
00:31:57,960 --> 00:31:58,760
R-GENERATEDDINE IS A THE SAME

931
00:31:58,760 --> 00:32:01,600
THING IN A SENSE AND IT SITS IN

932
00:32:01,600 --> 00:32:03,360
THE ARROWMATIC RESIDUES HERE

933
00:32:03,360 --> 00:32:05,400
THAT ALSO STABLEALIZE THE

934
00:32:05,400 --> 00:32:08,280
AMMONIUM OF ALCOHOLIN OR

935
00:32:08,280 --> 00:32:10,520
CARBOCOL, IT'S REPLACING THOSE

936
00:32:10,520 --> 00:32:11,240
INTERACTIONS, HIJACKING THAT

937
00:32:11,240 --> 00:32:13,080
SAME SET OF INTERACTIONS AND IT

938
00:32:13,080 --> 00:32:16,640
FORMS A PIE SANDWICH ON THIS AND

939
00:32:16,640 --> 00:32:19,600
IT BRINGS ALONG HALF OF THIS CAT

940
00:32:19,600 --> 00:32:21,920
ION PIE SANDWICH.

941
00:32:21,920 --> 00:32:25,080
YOU KNOW SO IT COMPIETS WITH THE

942
00:32:25,080 --> 00:32:26,440
NEUROTRANSMITTER AND KEEPS LOOP

943
00:32:26,440 --> 00:32:28,000
C FROM CLOSING WHICH IT LIKES TO

944
00:32:28,000 --> 00:32:29,960
DO AND - IT KEEPS THIS WHOLE

945
00:32:29,960 --> 00:32:31,280
INTERFACE FROM BECOMING MORE

946
00:32:31,280 --> 00:32:33,080
COMPACT WHICH IS WHAT HAPPENS

947
00:32:33,080 --> 00:32:35,160
WHEN AGONIST BIND, SO IT

948
00:32:35,160 --> 00:32:35,960
PREVENTS THE CONFIRMATIONAL

949
00:32:35,960 --> 00:32:37,840
CHANGES THAT LEAD TO CHANNEL

950
00:32:37,840 --> 00:32:39,240
OPENING AND MAKES SENSE WE WILL

951
00:32:39,240 --> 00:32:40,680
STABILIZE A RESTING STATE.

952
00:32:40,680 --> 00:32:41,840
SO WHAT ELSE IS INTERESTING

953
00:32:41,840 --> 00:32:42,400
ABOUT THIS.

954
00:32:42,400 --> 00:32:44,560
WELL, THERE ARE CRITTERS THAT

955
00:32:44,560 --> 00:32:46,480
HAVE EVOLVED SENSITIVITY TO THE

956
00:32:46,480 --> 00:32:48,240
SNAKE TOXINS AND THEY'RE REALLY

957
00:32:48,240 --> 00:32:50,680
NEAT SO THEY INCLUDE THINGS LIKE

958
00:32:50,680 --> 00:32:52,520
THE MONGOOSE AND COBRA.

959
00:32:52,520 --> 00:32:53,680
SO HOW DO THEY DO THAT?

960
00:32:53,680 --> 00:32:55,640
IN THE CASE OF THEE 2 ANIMALS

961
00:32:55,640 --> 00:32:58,120
THIS TRANSCRIPT O FAN RIGHT HERE

962
00:32:58,120 --> 00:33:00,680
ON LOOP C THAT STICKS OUT FROM

963
00:33:00,680 --> 00:33:05,760
THE CORE OF THE RECEPTOR CREATES

964
00:33:05,760 --> 00:33:06,280
A GLYCOSYLATION SITE.

965
00:33:06,280 --> 00:33:09,960
SO CAN YOU IMAGINE A BIG SUGAR

966
00:33:09,960 --> 00:33:12,280
BRANCH THING COMING OFF LOOP C

967
00:33:12,280 --> 00:33:14,800
WOULD INTERFERE WITH TOXIN

968
00:33:14,800 --> 00:33:16,080
BINDING.

969
00:33:16,080 --> 00:33:16,680
THAT'S PRETTY COOL.

970
00:33:16,680 --> 00:33:19,840
HONEY BADGERS AND PIGS, THE SAME

971
00:33:19,840 --> 00:33:22,840
TRANSCRIPT O FAN RESIDUE AND

972
00:33:22,840 --> 00:33:24,280
REPLACED WITH R-GENINE, IT

973
00:33:24,280 --> 00:33:26,520
DECREASES AFFINITY ENOUGH SO IT

974
00:33:26,520 --> 00:33:28,360
DOESN'T POINCH THE NEUROMSKULAR

975
00:33:28,360 --> 00:33:32,920
JUNCTION IN ANIMALS AND THEN

976
00:33:32,920 --> 00:33:37,400
THERE ARE NEURONAL NICOTINIC

977
00:33:37,400 --> 00:33:39,280
SUBSTITUTIONS, AND IT'S A LARGE

978
00:33:39,280 --> 00:33:43,440
PEPTIDE BUT NONE THE LESS,

979
00:33:43,440 --> 00:33:45,000
TYROSEEN RESIDUES, THIS IS

980
00:33:45,000 --> 00:33:46,400
TYROSEEN RESIDUE RIGHT HERE, PUT

981
00:33:46,400 --> 00:33:47,840
A POSITIVE CHARGEOT END OF IT,

982
00:33:47,840 --> 00:33:49,880
YOU NO LONGER GET HIGH,A FINNITY

983
00:33:49,880 --> 00:33:52,200
BINDING AND INHIBITION BY A

984
00:33:52,200 --> 00:33:52,480
NEUROTOXIN.

985
00:33:52,480 --> 00:33:57,120
ALL RIGHT, SO THAT'S BUNG

986
00:33:57,120 --> 00:33:57,400
AROTOXIN.

987
00:33:57,400 --> 00:34:00,800
SO WHAT ABOUT Q-ARY, AND I

988
00:34:00,800 --> 00:34:03,440
TALKED TO [INDISCERNIBLE] IS

989
00:34:03,440 --> 00:34:09,520
QARY IS THOUGHT TO BE A HIGH

990
00:34:09,520 --> 00:34:12,400
OPPOSED ANTAGONIST RECEPTOR.

991
00:34:12,400 --> 00:34:16,640
SO HE ALLUDED WITH CARBOCOLOFF

992
00:34:16,640 --> 00:34:17,720
THE PROTEIN AND HE GOT THE

993
00:34:17,720 --> 00:34:20,400
STRUCTURE THAT HAD TO OUR

994
00:34:20,400 --> 00:34:21,680
SURPRISE, D2 BOUND IN 1 AGONIST

995
00:34:21,680 --> 00:34:23,120
SITE AND 1 FOUND IN THE OTHER.

996
00:34:23,120 --> 00:34:24,480
SO THEN WE WENT AND DID WHAT WE

997
00:34:24,480 --> 00:34:26,440
SHOULD HAVE DONE WHICH WAS READ

998
00:34:26,440 --> 00:34:27,520
THE LITERATURE, YOU SHOULD

999
00:34:27,520 --> 00:34:28,600
ALWAYS READ THE LITERATURE AND

1000
00:34:28,600 --> 00:34:31,080
FOUND THAT OF COURSE, THIS SITE

1001
00:34:31,080 --> 00:34:33,480
HAS A 500 FOLD HIGHER AFFINITY

1002
00:34:33,480 --> 00:34:35,920
FOR D2 AND THIS SITE AS HAS A 2

1003
00:34:35,920 --> 00:34:37,280
FOLD FOR HIGHER, SO IT MAKES

1004
00:34:37,280 --> 00:34:38,880
SENSE, AND I'M NOT GOING TO TRAG

1005
00:34:38,880 --> 00:34:39,960
IT THROUGH THE DETAILS BUT I DO

1006
00:34:39,960 --> 00:34:41,520
HAVE A SLIDE IF YOU WANT TO ASK

1007
00:34:41,520 --> 00:34:44,280
ON WHY DOES IT PREFER THESE

1008
00:34:44,280 --> 00:34:46,840
SITES AND IT DOES BUT IT MAKES

1009
00:34:46,840 --> 00:34:47,040
SENSE.

1010
00:34:47,040 --> 00:34:48,560
>>I SAID ALL RIGHT, I
WANT TO

1011
00:34:48,560 --> 00:34:50,520
GET A STRUCTURE, DON'T YOU OF

1012
00:34:50,520 --> 00:34:52,680
THE RECEPTOR BOUND TO SEE WHAT

1013
00:34:52,680 --> 00:34:54,080
THE CONFIRMATION OF THE POUR

1014
00:34:54,080 --> 00:34:58,080
LOOKS LIKE, I SAID AND WE SAID

1015
00:34:58,080 --> 00:35:00,520
YES, LET'S DO THAT, 200

1016
00:35:00,520 --> 00:35:02,240
MICROMOLAR FOR THIS ANTAGONIST

1017
00:35:02,240 --> 00:35:04,680
AND HE THEN FOUND IT BINDS BOTH

1018
00:35:04,680 --> 00:35:07,120
THE ALPHA GAMMAA AND ALPHA DELTA

1019
00:35:07,120 --> 00:35:08,280
INTERFACES AND IT BYPASSEDS IN

1020
00:35:08,280 --> 00:35:10,360
THE CHANNEL BLOCK SITE AND THIS

1021
00:35:10,360 --> 00:35:12,040
WAS THE BIG SURPRISE, IS THAT IT

1022
00:35:12,040 --> 00:35:15,000
BINDS IN THIS KIND OF DOWN IN

1023
00:35:15,000 --> 00:35:16,200
THE TRANSMEMBRANE DOMAIN BUT ON

1024
00:35:16,200 --> 00:35:17,440
THE EXTRA CELLULAR SIDE, JUST

1025
00:35:17,440 --> 00:35:19,160
POKING OUT OF THE EXTRA CELLULAR

1026
00:35:19,160 --> 00:35:21,160
SIDE OF THE INTERFACE.

1027
00:35:21,160 --> 00:35:24,200
AND THE WAY IT FITS IN THERE, IS

1028
00:35:24,200 --> 00:35:26,080
THIS M4, THE LAST HELIX FROM

1029
00:35:26,080 --> 00:35:28,600
THIS ALPHA SUBUNIT BECOMES

1030
00:35:28,600 --> 00:35:30,280
DETACHED, SO THIS INTERACTION

1031
00:35:30,280 --> 00:35:31,440
HERE WITH THIS LITTLE SHORT

1032
00:35:31,440 --> 00:35:33,560
HELIX HERE THAT MAKES US

1033
00:35:33,560 --> 00:35:36,440
INTERACTION WITH WHAT WE CALL

1034
00:35:36,440 --> 00:35:38,200
THE COUPLING REGION, THAT

1035
00:35:38,200 --> 00:35:38,840
INTERACTION IS SEVERED, THIS

1036
00:35:38,840 --> 00:35:44,160
TINNING OPENS UP AND ALLOWS

1037
00:35:44,160 --> 00:35:46,120
D-TUBO TO BIND IN THERE.

1038
00:35:46,120 --> 00:35:49,760
SO WE THEN SPENT TIME AND I WILL

1039
00:35:49,760 --> 00:35:52,560
WALK YOU THROUGH IT OF USING TOO

1040
00:35:52,560 --> 00:35:54,360
MUCH PURINE OR IS THIS SHOWING

1041
00:35:54,360 --> 00:35:56,040
US SOMETHING INTERESTING ABOUT A

1042
00:35:56,040 --> 00:35:57,640
MODULATORS SITE, A NEW DRUGGABLE

1043
00:35:57,640 --> 00:35:59,080
SITE OR INSIGHT INTOS HOW

1044
00:35:59,080 --> 00:36:00,200
CHANNELS WORK AND I WILL TAKE

1045
00:36:00,200 --> 00:36:00,640
YOU THROUGH THAT.

1046
00:36:00,640 --> 00:36:02,520
I THINK THERE IS SOMETHING

1047
00:36:02,520 --> 00:36:03,040
INTERESTING THERE.

1048
00:36:03,040 --> 00:36:08,200
SO BUT A BASIC QUESTION WAS WHAT

1049
00:36:08,200 --> 00:36:09,240
CONFIRMATIONAL STATE DOES T-DUBO

1050
00:36:09,240 --> 00:36:11,040
STABILIZE, SO I'M SHOWING 3

1051
00:36:11,040 --> 00:36:12,800
TRACES I SHOWED YOU BEFORE, THE

1052
00:36:12,800 --> 00:36:15,160
RESTING STATE ON THE LEFT WHICH

1053
00:36:15,160 --> 00:36:16,880
IS CLOSED TIGHTLY AT THE TOP AND

1054
00:36:16,880 --> 00:36:21,240
MIDDLE AND WE SEE THAT BOTH

1055
00:36:21,240 --> 00:36:22,880
STRUCTURES WITH D-DUBO BOUND

1056
00:36:22,880 --> 00:36:24,480
LOOK LIKE DESENSITIZED CONFIRM

1057
00:36:24,480 --> 00:36:25,520
AS OF THE FORE.

1058
00:36:25,520 --> 00:36:27,680
WHICH MAKES SENSE GIVEN THAT AS

1059
00:36:27,680 --> 00:36:31,200
I TOLD YOU T-TUBO CAN ACT AS A

1060
00:36:31,200 --> 00:36:32,120
PARTIAL AGONIST SO WE CAN THINK

1061
00:36:32,120 --> 00:36:36,600
OF IT AS A LOW EFFICACY AGONIST

1062
00:36:36,600 --> 00:36:37,520
THAT STABILIZES DESENSITIZED

1063
00:36:37,520 --> 00:36:38,960
STATE WITHOUT MUCH CHANNEL

1064
00:36:38,960 --> 00:36:39,400
OPENING.

1065
00:36:39,400 --> 00:36:39,920
OKAY.

1066
00:36:39,920 --> 00:36:41,920
SO WHAT ABOUT THIS SITE, THIS

1067
00:36:41,920 --> 00:36:43,680
SITE WILL BE THE FOCUS OF THE

1068
00:36:43,680 --> 00:36:46,200
REST OF THE TALK.

1069
00:36:46,200 --> 00:36:46,800
GREAT.

1070
00:36:46,800 --> 00:36:49,640
SO HERE IS--I WILL SHOW YOU 2

1071
00:36:49,640 --> 00:36:50,440
STRUCTURAL OVERLIES, HERA 1 ON

1072
00:36:50,440 --> 00:36:52,440
THE LEFT WHERE WE'RE SUPER

1073
00:36:52,440 --> 00:36:53,760
IMPOSSESSING THE ALPHA SUBUNITS

1074
00:36:53,760 --> 00:36:56,120
AND THE RESTING STATE IN GRAY

1075
00:36:56,120 --> 00:36:56,920
AND THE DESENSITIZED STATE IN

1076
00:36:56,920 --> 00:36:58,720
GREEN AND MOST OF THE CORE OF

1077
00:36:58,720 --> 00:37:00,440
THE STRUCTURES OVERLAY QUITE

1078
00:37:00,440 --> 00:37:01,840
WELL, THE CONFIRMATION OF THE

1079
00:37:01,840 --> 00:37:02,400
PORE IS DIFFERENT.

1080
00:37:02,400 --> 00:37:05,080
I'VE SHOWED YOU THE THESE GRAFS,

1081
00:37:05,080 --> 00:37:06,400
THE DESENSITIZED STATE IS MORE

1082
00:37:06,400 --> 00:37:08,480
OPEN, AND THEN WHAT WE STARTED

1083
00:37:08,480 --> 00:37:10,760
NOTICING IS AFTER ONLY REALLY

1084
00:37:10,760 --> 00:37:13,040
LOOKING AT THESE D-TUBO SITE,

1085
00:37:13,040 --> 00:37:14,240
THERE'S SOMETHING FUNNY GOING ON

1086
00:37:14,240 --> 00:37:15,960
WITH THE CONFIRMATION OF THE

1087
00:37:15,960 --> 00:37:18,240
C-TERM NIGH OF THE M4 HELIX, SO

1088
00:37:18,240 --> 00:37:19,600
THE VERY END OF THE RECEPTOR

1089
00:37:19,600 --> 00:37:20,960
POKING OUT INTO THE EXTRA

1090
00:37:20,960 --> 00:37:22,960
CELLULAR SPACE FROM JUST THE

1091
00:37:22,960 --> 00:37:24,280
ALPHA SUBUNITS, THERE ARE

1092
00:37:24,280 --> 00:37:24,920
DIFFERENT CONFIRMATION SAYS AND

1093
00:37:24,920 --> 00:37:26,320
THE REST OF THE STATE, THIS HAS

1094
00:37:26,320 --> 00:37:27,760
NOT BEEN SEEN BEFORE AND OTHER

1095
00:37:27,760 --> 00:37:30,360
NICK O 10IC RECEPTORS OR OTHER

1096
00:37:30,360 --> 00:37:31,160
RECEPTORS, SOMETHING FUNNY

1097
00:37:31,160 --> 00:37:33,960
PECULIAR TO THE MUSCLE RECEPTOR.

1098
00:37:33,960 --> 00:37:35,920
SO THIS SUBUNIT HERE BECOMES

1099
00:37:35,920 --> 00:37:36,880
VERY DETEACHED AND DENSITY FOR

1100
00:37:36,880 --> 00:37:38,880
THE END OF THIS HELIX

1101
00:37:38,880 --> 00:37:41,200
DISAPPEARS, CAN'T MODEL IS,

1102
00:37:41,200 --> 00:37:41,560
RIGHT?

1103
00:37:41,560 --> 00:37:43,200
OKAY, SO THEN WE CAN EUROPE

1104
00:37:43,200 --> 00:37:44,120
IMPOSE RESTING WHICH WE HAVE

1105
00:37:44,120 --> 00:37:45,640
OVER HERE IN GRAY, AND OVER HERE

1106
00:37:45,640 --> 00:37:48,880
IN GRAY AND THEN DID,-TUBO IN

1107
00:37:48,880 --> 00:37:50,200
THIS CASE WILL BE IN GREEN.

1108
00:37:50,200 --> 00:37:51,880
WE CAN SEE BINDS IN 1 OF THESE

1109
00:37:51,880 --> 00:37:54,200
SITES WHERE THE M-4 HELIX

1110
00:37:54,200 --> 00:37:56,080
BECOMES DETACHED AND AGAIN WE'RE

1111
00:37:56,080 --> 00:37:57,200
STILL WONDERING IS THIS

1112
00:37:57,200 --> 00:37:57,680
MEANINGFUL OR NOT.

1113
00:37:57,680 --> 00:37:59,760
SO I CAN SUMMARIZE WHAT I'M

1114
00:37:59,760 --> 00:38:00,360
SHOWING YOU HERE.

1115
00:38:00,360 --> 00:38:03,360
IN THE RESTING STATE, THESE ARE

1116
00:38:03,360 --> 00:38:05,400
THE 2 M4 HELIXES AND THEY'RE

1117
00:38:05,400 --> 00:38:07,360
ATTACHED TO THE RECEPTOR, AND

1118
00:38:07,360 --> 00:38:08,760
DESENSITIZED STATE 1 OF THEM

1119
00:38:08,760 --> 00:38:11,040
OPENS UP A BIT AND THIS

1120
00:38:11,040 --> 00:38:14,480
RECALLING 1 OPENS UP A LOT;

1121
00:38:14,480 --> 00:38:17,400
OKAY, SO WHY CAN'T D-TUBO BIND

1122
00:38:17,400 --> 00:38:18,000
OVER HERE?

1123
00:38:18,000 --> 00:38:19,960
WE THINK BECAUSE THEY'RE NOT

1124
00:38:19,960 --> 00:38:21,720
RECEPTORS, THE WHO UNITS WHILE

1125
00:38:21,720 --> 00:38:23,160
THEY'RE ADENTICAL IN SEQUENCE,

1126
00:38:23,160 --> 00:38:25,120
THEY'RE NOT IDENTICAL IN THEIR

1127
00:38:25,120 --> 00:38:26,160
NEIGHBORING SUBUNITS IN THE

1128
00:38:26,160 --> 00:38:28,360
STRUCTURE SO WE'RE GUESSING THAT

1129
00:38:28,360 --> 00:38:30,040
THE FACT THIS 1'S NEXT TO A

1130
00:38:30,040 --> 00:38:32,880
DELTA SUBAUTOPSY SERIES CAN

1131
00:38:32,880 --> 00:38:37,040
RESTRAIN MOTION, D-TUBE O IS

1132
00:38:37,040 --> 00:38:39,120
BIG, THAT'S A GUESS.

1133
00:38:39,120 --> 00:38:41,560
SO SO WE WILL LOOK AT IN DETAIL

1134
00:38:41,560 --> 00:38:44,600
WHAT'S HAPPENING TO AMINO ACIDS

1135
00:38:44,600 --> 00:38:46,240
IN IN CONFIRMATIONAL CHANGE FROM

1136
00:38:46,240 --> 00:38:47,200
RESTING TO DESENSITIZED STATE.

1137
00:38:47,200 --> 00:38:57,680
SO THE FEENLE AN LEANS, THIS

1138
00:38:58,960 --> 00:39:00,280
NEST OF THEM, 3 OF THEM THAT

1139
00:39:00,280 --> 00:39:01,800
PACK TIGHTLY DIGNITARY THEY

1140
00:39:01,800 --> 00:39:05,240
CHANGE IN CONFIRMATION AND

1141
00:39:05,240 --> 00:39:06,520
DURING DESENSITIZATION M4 RIGHT

1142
00:39:06,520 --> 00:39:08,520
HERE ADOPTS A ROTE MERCHANGE AND

1143
00:39:08,520 --> 00:39:10,040
FOR IT TO RECOVER, THIS IS OUR

1144
00:39:10,040 --> 00:39:12,040
IDEA, FOR IT TO RECOVER FROM

1145
00:39:12,040 --> 00:39:16,280
DENSE SENSITIZATION TO GO BACK

1146
00:39:16,280 --> 00:39:17,120
TO THE RESTING STATE THIS CHANGE

1147
00:39:17,120 --> 00:39:19,080
WOULD HAVE TO GOOD LUCK BACK TO

1148
00:39:19,080 --> 00:39:20,000
THE RESTING SECTION AND MAYBE

1149
00:39:20,000 --> 00:39:22,120
THAT WOULD BREAK ON

1150
00:39:22,120 --> 00:39:22,800
DESENSITIZATION, MAYBE, MAYBE,

1151
00:39:22,800 --> 00:39:24,840
DON'T KNOW HOW CAN WE TEST THIS,

1152
00:39:24,840 --> 00:39:26,360
LET'S MAKE MUTANTS IN THE SIDE

1153
00:39:26,360 --> 00:39:28,640
CHAINS SO WE DO THAT, ME MAKE

1154
00:39:28,640 --> 00:39:29,760
SINGLE, DOUBLE, TRIPLE MUTANTS

1155
00:39:29,760 --> 00:39:32,440
WE DO THE VOLTAGE CLAMP, AND WE

1156
00:39:32,440 --> 00:39:34,720
SEE SO ON THE FAR RIGHT SIDE

1157
00:39:34,720 --> 00:39:37,080
HERE, THE SOLID CIRCLES, ARE

1158
00:39:37,080 --> 00:39:44,800
WILD-TYPE, AND THEN AS WE MAKE

1159
00:39:44,800 --> 00:39:48,760
INCREASING NUMBER OF FEIGNLE

1160
00:39:48,760 --> 00:39:51,080
ALA19, WE SEE THE EC 50 TO THE

1161
00:39:51,080 --> 00:39:53,080
LEFT SO WHEN YOU GET RID OF

1162
00:39:53,080 --> 00:39:54,600
THESE BULKY RESIDUES HERE AND

1163
00:39:54,600 --> 00:39:58,240
YOU REPLACE THEM WITH

1164
00:39:58,240 --> 00:40:03,120
ALANINEs, IT'S EASIER TO

1165
00:40:03,120 --> 00:40:04,040
AGGRAVATE THE CHANNEL.

1166
00:40:04,040 --> 00:40:04,280
WHY?

1167
00:40:04,280 --> 00:40:05,320
CAN WE GO DEEPER?

1168
00:40:05,320 --> 00:40:08,760
WE WANT TO LOOK AT, SIMPLE

1169
00:40:08,760 --> 00:40:11,960
KINETICS AND THE REAL

1170
00:40:11,960 --> 00:40:12,760
ELECTROPHYSIOLOGIST HERE, TRY

1171
00:40:12,760 --> 00:40:14,880
NOT TO JUDGE ME--[LAUGHTER]

1172
00:40:14,880 --> 00:40:16,160
--I HOPE THIS DOESN'T IRRITATE

1173
00:40:16,160 --> 00:40:21,320
YOU TOO MUCH BUT WE WILL SEE, WE

1174
00:40:21,320 --> 00:40:22,680
WANTED FASTER EXCHANGE, SO WE

1175
00:40:22,680 --> 00:40:24,360
SWITCHED AND TO DO THAT WE HAD

1176
00:40:24,360 --> 00:40:26,080
TO SWITCH IN TORPEDO WHICH

1177
00:40:26,080 --> 00:40:27,240
DOESN'T EXPRESS AT WARM

1178
00:40:27,240 --> 00:40:28,600
TEMPERATURES, TO THE MOUSE

1179
00:40:28,600 --> 00:40:30,600
MUSCLE NICK O 10IC RECEPTOR SO

1180
00:40:30,600 --> 00:40:32,560
WE MAY SUBSIDIARY TUITIONS THERE

1181
00:40:32,560 --> 00:40:33,280
AND LOOKED AT OUR

1182
00:40:33,280 --> 00:40:34,040
CERTAINLY--CERTAINLY LECT ROUGH

1183
00:40:34,040 --> 00:40:35,760
ATOM PHYSIOLOGIST AND WE'RE

1184
00:40:35,760 --> 00:40:37,080
LOOKING AT WILD-TYPE, LONG

1185
00:40:37,080 --> 00:40:40,680
APPLICATIONS OF AGONIST AND THEN

1186
00:40:40,680 --> 00:40:43,880
SECOND PULSES OF AGONIST TO LOOK

1187
00:40:43,880 --> 00:40:44,840
AT RECOVERY FROM

1188
00:40:44,840 --> 00:40:46,800
DESENSITIZATION, WE DO THAT WITH

1189
00:40:46,800 --> 00:40:48,680
GAIN OF FUNCTION DOUBLE MUTANTS,

1190
00:40:48,680 --> 00:40:55,120
SO WE CAN CHANGE THE DURATION OF

1191
00:40:55,120 --> 00:40:56,280
RECOVERY FROM--SO WE ACTIVATE

1192
00:40:56,280 --> 00:40:58,240
AND WE APPLY FOR AGONIST LONG

1193
00:40:58,240 --> 00:40:59,440
ENOUGH TO GET STEADY STATE

1194
00:40:59,440 --> 00:41:01,400
CURRENT AND MOST ARE

1195
00:41:01,400 --> 00:41:02,800
DESENSITIZED AT THIS POINT SO AS

1196
00:41:02,800 --> 00:41:04,600
WE INCREASE THE AMOUNT OF TIME

1197
00:41:04,600 --> 00:41:05,640
BEFORE THE SECOND PULSE, WE CAN

1198
00:41:05,640 --> 00:41:07,960
GET A ROUGH ESTIMATE OF AN

1199
00:41:07,960 --> 00:41:09,840
APPARENT RECOVERY RATE FROM

1200
00:41:09,840 --> 00:41:11,600
DESENSITIZATION, WE CAN FIT A

1201
00:41:11,600 --> 00:41:13,840
SUM OF 2 EXPONENTIALS FROM THE

1202
00:41:13,840 --> 00:41:14,280
RECOVERY RATE.

1203
00:41:14,280 --> 00:41:14,880
3.8 SECONDS.

1204
00:41:14,880 --> 00:41:16,120
HOW DOES THAT COMPARE TO THE

1205
00:41:16,120 --> 00:41:16,400
MUTANT.

1206
00:41:16,400 --> 00:41:18,080
SO WE DO THE SAME MUTANT THAT

1207
00:41:18,080 --> 00:41:20,360
HAD THE GAIN OF FUNCTION AND WE

1208
00:41:20,360 --> 00:41:22,000
SEE THAT MAYBE YOU CAN ALREADY

1209
00:41:22,000 --> 00:41:23,640
TELL, THIS THING IS RECOVERY

1210
00:41:23,640 --> 00:41:26,160
MUCH FASTER FROM BEING

1211
00:41:26,160 --> 00:41:26,480
DESENSITIZED.

1212
00:41:26,480 --> 00:41:28,920
SO 5 FOLD FASTER, SOMETHING LIKE

1213
00:41:28,920 --> 00:41:29,280
THAT.

1214
00:41:29,280 --> 00:41:32,240
SO WE CAN CONNECT THIS GAIN OF

1215
00:41:32,240 --> 00:41:34,080
FUNCTION, THESE FEIGN

1216
00:41:34,080 --> 00:41:36,200
ALEXANDERRA 9 SIDE CHAINS WE

1217
00:41:36,200 --> 00:41:39,560
PRUNED BACK TO ALA19S AND

1218
00:41:39,560 --> 00:41:40,400
APPARENT RECOVERY FROM

1219
00:41:40,400 --> 00:41:43,760
DESENSITIZATION, SO THAT'S THE

1220
00:41:43,760 --> 00:41:46,000
IDEA THAT WHEN THIS M4 HELIX

1221
00:41:46,000 --> 00:41:46,960
BECOMES DETACHED THAT'S EITHER

1222
00:41:46,960 --> 00:41:49,400
PART OF ACTIVATION OR ACTIVATION

1223
00:41:49,400 --> 00:41:50,000
OF DESENSITIZATION, WE DON'T

1224
00:41:50,000 --> 00:41:51,440
KNOW WE DON'T HAVE AN ACTIVATED

1225
00:41:51,440 --> 00:41:54,120
STATE BUT FOR IT TO RECOVER FROM

1226
00:41:54,120 --> 00:41:54,720
BEING DESENSITIZED THAT HELIX

1227
00:41:54,720 --> 00:42:00,240
HAS TO COME BACK INTO POSITION

1228
00:42:00,240 --> 00:42:03,800
AND THAT IT BE LIMITED BY THE

1229
00:42:03,800 --> 00:42:11,240
ROTOMERRIC SHIFTS AND THESE

1230
00:42:11,240 --> 00:42:11,560
FENALANINES.

1231
00:42:11,560 --> 00:42:13,360
WE HAVE NO IDEA HOW IT REGULATES

1232
00:42:13,360 --> 00:42:15,040
BECAUSE IT'S A LOW AFFINITY SITE

1233
00:42:15,040 --> 00:42:16,320
COMPARED TO EXTRA CELLULAR

1234
00:42:16,320 --> 00:42:18,200
DOMAININNA SITES WHERE IT'S

1235
00:42:18,200 --> 00:42:19,600
REALLY DOING ITSAN TAGANIST JOB.

1236
00:42:19,600 --> 00:42:22,080
SO HOW DO YOU MEASURE THE

1237
00:42:22,080 --> 00:42:23,720
ACTIVITY OF A SECONDAN TAGANIST

1238
00:42:23,720 --> 00:42:25,120
SITE, DON'T KNOW SO WE STARTED

1239
00:42:25,120 --> 00:42:26,880
LOOKING AT OTHER LIGANDS AND 1

1240
00:42:26,880 --> 00:42:31,120
OF THEM WAS ATOM OIDATE WHICH IS

1241
00:42:31,120 --> 00:42:32,400
AN INTRAVENOUS ANESTHETIC WITH

1242
00:42:32,400 --> 00:42:36,840
THE GABBA A RECEPTOR AND THEY

1243
00:42:36,840 --> 00:42:38,800
BIND AT SUBUNIT INTERFACES WHERE

1244
00:42:38,800 --> 00:42:48,520
THEY ARE POSITIVE MODULATORS. 

1245
00:42:48,520 --> 00:42:50,040
ETOMIDATE BINDS TO THE M4, SO

1246
00:42:50,040 --> 00:42:53,280
IT'S WHY YOU GET MUSCLE

1247
00:42:53,280 --> 00:42:55,840
RELAXATION DURAN CANNING GENERAL

1248
00:42:55,840 --> 00:42:56,120
ANESTHESIA.

1249
00:42:56,120 --> 00:42:58,360
SO ETOMIDATE BINDS IN THE SAME

1250
00:42:58,360 --> 00:43:00,320
SIGHT THAT IT BINDS IN AND IT

1251
00:43:00,320 --> 00:43:01,400
ONLY BINDS THERE, AND DOESN'T

1252
00:43:01,400 --> 00:43:04,080
BIND IN OTHER PLACES AND WE HAVE

1253
00:43:04,080 --> 00:43:06,360
STRUCTURES NOW WITH BOTH

1254
00:43:06,360 --> 00:43:07,160
CARBOCOLAND CHOLINE BOUND HERE

1255
00:43:07,160 --> 00:43:09,640
AND THESE 2 WORK TOGETHER TO

1256
00:43:09,640 --> 00:43:10,600
STABILIZE DESENSITIZED STATES OF

1257
00:43:10,600 --> 00:43:18,640
THE CHANNEL, SO WE CAN LOOK AT

1258
00:43:18,640 --> 00:43:20,840
THE ETOMIDATE SITE HERE AND WHEN

1259
00:43:20,840 --> 00:43:24,560
WE LOOK AT AFTIO CHOLINE AND

1260
00:43:24,560 --> 00:43:26,120
INCREASING CONCENTRATIONS OF

1261
00:43:26,120 --> 00:43:28,160
D-TUBO WE SEE WHAT LOOKS LIKE A

1262
00:43:28,160 --> 00:43:31,880
RATE IN THE FAST

1263
00:43:31,880 --> 00:43:33,040
DESENSITIZATION, SO ETOMIDATE IS

1264
00:43:33,040 --> 00:43:34,720
SITTING IN THERE THROUGH

1265
00:43:34,720 --> 00:43:35,320
ENHANCING DESENSITIZATION.

1266
00:43:35,320 --> 00:43:37,120
SO THIS WAS A RELIEF BECAUSE WE

1267
00:43:37,120 --> 00:43:41,120
WEREN'T SURE WHAT TO MAKE OUT OF

1268
00:43:41,120 --> 00:43:43,200
THIS D-TUBO SITE, WAS IT AN

1269
00:43:43,200 --> 00:43:46,200
ARTIFACT OF USING TOO MUCH

1270
00:43:46,200 --> 00:43:47,760
D-TUBO, WE THINK IT WAS CLUEING

1271
00:43:47,760 --> 00:43:49,040
US INTO SOMETHING

1272
00:43:49,040 --> 00:43:49,840
MECHANISTICALLY AND NOW WE HAVE

1273
00:43:49,840 --> 00:43:51,640
A DRUG THAT'S USED ALL THE TIME

1274
00:43:51,640 --> 00:43:53,520
IN THE CLINIC THAT BINDS THERE

1275
00:43:53,520 --> 00:43:54,320
AND ONLY THERE.

1276
00:43:54,320 --> 00:43:56,560
OKAY, SO TO SUMMARIZE I'VE SHOWN

1277
00:43:56,560 --> 00:43:58,480
YOU THE RESTING STATE OF THE

1278
00:43:58,480 --> 00:44:01,040
REPRESENTOR WHERE THE PORE IS

1279
00:44:01,040 --> 00:44:02,800
CLOSED, VERTICALLY, AND THE

1280
00:44:02,800 --> 00:44:04,680
DESENSITIZED STATE, THE TOP,

1281
00:44:04,680 --> 00:44:05,720
IT'S--THE PORE IS FUNNEL SHAPED

1282
00:44:05,720 --> 00:44:08,080
SO THE TOP OF IT OPENS UP, BUT

1283
00:44:08,080 --> 00:44:09,960
THE BOTTOM STAYS CLOSED, 1 OF

1284
00:44:09,960 --> 00:44:13,440
THE M4S POPS OPEN, WHEN D-TUBO'S

1285
00:44:13,440 --> 00:44:15,080
BOUND IT FITS IN THE SITE IN

1286
00:44:15,080 --> 00:44:19,960
ADDITION TO THESE OTHER SITES

1287
00:44:19,960 --> 00:44:22,120
AND THEN ETOMIDATE TAKES THE

1288
00:44:22,120 --> 00:44:23,520
CONFIRMATION IN THE DESENSITIZED

1289
00:44:23,520 --> 00:44:25,480
STATE AND SIT THERE IS TO

1290
00:44:25,480 --> 00:44:27,800
PREVENT SLOW RECOVER FREE

1291
00:44:27,800 --> 00:44:28,320
RADICALS DESENSITIZATION.

1292
00:44:28,320 --> 00:44:29,840
OKAY, SO I'VE SHOWN YOU THE

1293
00:44:29,840 --> 00:44:33,640
ARCHITECTURE OF APO RECEPTOR AND

1294
00:44:33,640 --> 00:44:34,040
LIPID INTERACTIONS

1295
00:44:34,040 --> 00:44:34,680
CONFIRMATIONAL CHANGES

1296
00:44:34,680 --> 00:44:36,680
UNDERLYING THE STATE TRANSITIONS

1297
00:44:36,680 --> 00:44:41,160
BUT NOT ALL, DISTINCT MECHANISMS

1298
00:44:41,160 --> 00:44:43,480
UNDERLYING RESUPPORT

1299
00:44:43,480 --> 00:44:44,360
ORANTAGONISM, AND D-TUBO

1300
00:44:44,360 --> 00:44:45,480
DESTABILIZED THE END STATE.

1301
00:44:45,480 --> 00:44:47,680
THE SAME RESULT IS THE SAME.

1302
00:44:47,680 --> 00:44:50,800
YOU GET MUSCLE PARALYSIS, THE M4

1303
00:44:50,800 --> 00:44:52,000
HELIX DETACHES DURING

1304
00:44:52,000 --> 00:44:53,320
DESENSITIZATION AND SOME LIGANDS

1305
00:44:53,320 --> 00:44:56,200
CAN TAKE ADVANTAGE OF THIS TO

1306
00:44:56,200 --> 00:44:56,720
ALOESTERICALLY INHIBIT THE

1307
00:44:56,720 --> 00:44:57,000
RESOPTOR.

1308
00:44:57,000 --> 00:44:58,240
THERE'S STILL A LOT TO DO WE

1309
00:44:58,240 --> 00:44:59,360
DON'T HAVE AN ACTIVATED STATE

1310
00:44:59,360 --> 00:45:01,800
AND WIRE TRYING TO GET THIS IS

1311
00:45:01,800 --> 00:45:03,960
WE HAVE CAGED AGONIST THAT

1312
00:45:03,960 --> 00:45:05,280
MICHAEL STOLE HAS SYNTHITIZED

1313
00:45:05,280 --> 00:45:06,920
AND WE HAVE A LIGHT PIPE COMING

1314
00:45:06,920 --> 00:45:08,840
INTO THE SAMPLE LOADING WIND

1315
00:45:08,840 --> 00:45:10,480
UPON OS IN THE [INDISCERNIBLE].

1316
00:45:10,480 --> 00:45:12,720
SO AS THE SAMPLE DROPS THROUGH

1317
00:45:12,720 --> 00:45:13,920
THAT AND UNCAGES THE AGONIST AND

1318
00:45:13,920 --> 00:45:16,880
MAYBE WE WILL GET AN ACTIVATED

1319
00:45:16,880 --> 00:45:17,360
STATE.

1320
00:45:17,360 --> 00:45:20,800
SO FAR WHAT WE'VE GOTTEN IS THE

1321
00:45:20,800 --> 00:45:22,160
CAGED AGONIST BOUND WHICH IS NOT

1322
00:45:22,160 --> 00:45:25,240
INFORMED TO ANYTHING BUT WE'RE

1323
00:45:25,240 --> 00:45:26,840
MAKING PROGRESS SLOWLY.

1324
00:45:26,840 --> 00:45:28,600
STRUCTURAL PHARMACOLOGY OF

1325
00:45:28,600 --> 00:45:29,600
MODERN NEUROMUSCULAR JUNCTION

1326
00:45:29,600 --> 00:45:31,560
BLOCKERS, SO IF YOU NEED TO HAVE

1327
00:45:31,560 --> 00:45:32,240
GENERAL ANESTHESIA, THEY ARE

1328
00:45:32,240 --> 00:45:34,240
GOING TO GIVE YOU A COMBINATION

1329
00:45:34,240 --> 00:45:39,160
OF A GENERAL ANESTHETIC WHETHER

1330
00:45:39,160 --> 00:45:41,680
IT'S PROFOFOL OR KETAMINE THAT

1331
00:45:41,680 --> 00:45:46,280
ACTS ON NMDA RECEPTORS AND A

1332
00:45:46,280 --> 00:45:47,000
NEUROMUSCULAR BLOCKER, SOMETHING

1333
00:45:47,000 --> 00:45:48,640
LIKE THOSE TO PARALYZE SKELETAL

1334
00:45:48,640 --> 00:45:49,760
MUSCLE OPEN SOURCE SOFTWAREY

1335
00:45:49,760 --> 00:45:51,760
THEY CAN INTUBATE YOU AND USE A

1336
00:45:51,760 --> 00:45:53,240
LOWER DOSE OF GENERALLANCE

1337
00:45:53,240 --> 00:45:54,080
ESTIMATE THADTHETIC THESE 2

1338
00:45:54,080 --> 00:45:56,600
THINGS ARE USED TOGETHER.

1339
00:45:56,600 --> 00:45:58,160
SO NEUROMUSCULAR BLOCKERS AND

1340
00:45:58,160 --> 00:45:59,080
GENERAL ANESTHETICS AND IT'S

1341
00:45:59,080 --> 00:46:00,600
INTERESTING THEY CAN ACT SINNER

1342
00:46:00,600 --> 00:46:01,800
GESTICLY OR TOGETHER AT THE SAME

1343
00:46:01,800 --> 00:46:04,640
TIME ON THE SAME CHANNEL.

1344
00:46:04,640 --> 00:46:06,200
AND THEN THE BIG NEW AREA IN THE

1345
00:46:06,200 --> 00:46:07,720
LAB IS LOOKING AT NATIVE

1346
00:46:07,720 --> 00:46:09,480
RECEPTOR STRUCTURES WHETHER IT'S

1347
00:46:09,480 --> 00:46:11,040
BY TOMOGRAPHY OR PURIFYING

1348
00:46:11,040 --> 00:46:15,280
RECEPTORS AND COMPLEXES FROM

1349
00:46:15,280 --> 00:46:15,520
TISSUE.

1350
00:46:15,520 --> 00:46:17,120
LRLT, SO THANK YOU VERY MUCH

1351
00:46:17,120 --> 00:46:18,960
THIS IS MY GROUP.

1352
00:46:18,960 --> 00:46:21,080
MICHAEL HAS BEEN GREAT IN

1353
00:46:21,080 --> 00:46:22,920
CHEMISTRY, STEVE PROVIDING GENES

1354
00:46:22,920 --> 00:46:23,880
AND DISCUSSIONS, ARTHUR

1355
00:46:23,880 --> 00:46:26,120
PREGNANTED OUT HOW TO PURIFY

1356
00:46:26,120 --> 00:46:27,160
THIS THING AND FUNDING AND BE

1357
00:46:27,160 --> 00:46:37,600
HAPPY TO TAKE QUESTIONS.

1358
00:46:39,440 --> 00:46:39,680
[ APPLAUSE ]

1359
00:46:39,680 --> 00:46:42,160
>>YES BUT YOU'RE SUPPOSED
TO

1360
00:46:42,160 --> 00:46:43,720
USE THE MICROPHONE.

1361
00:46:43,720 --> 00:46:45,720
>>SO LOVELY STUFF, RYAN,
I

1362
00:46:45,720 --> 00:46:46,920
GUESS, I HAVE A LOT OF QUESTIONS

1363
00:46:46,920 --> 00:46:49,800
ABOUT YOU THE 1 THAT SORT OF

1364
00:46:49,800 --> 00:46:51,800
KEEPS COMING BACK IS THE IDEA OF

1365
00:46:51,800 --> 00:46:53,040
THE POLYPHARMACOLOGY, THE WHYED

1366
00:46:53,040 --> 00:46:56,320
THAT THE SAME DRUG ACTS AS AN

1367
00:46:56,320 --> 00:46:57,560
INHIBITOR IN 1 SITE IN THE GATE

1368
00:46:57,560 --> 00:47:00,480
KEEPER BA RECEPTORS AND

1369
00:47:00,480 --> 00:47:01,040
ACTIVATOR IN THESE.

1370
00:47:01,040 --> 00:47:03,480
AND I MEAN, IS THERE AN

1371
00:47:03,480 --> 00:47:04,640
EVOLUTIONARY BASIS OF THIS OR

1372
00:47:04,640 --> 00:47:07,000
DOES IT FIT IN SPACES THAT ARE

1373
00:47:07,000 --> 00:47:09,880
IN EVERY PROTEIN?

1374
00:47:09,880 --> 00:47:12,400
I MEAN, HOW DOES THAT COME ABOUT

1375
00:47:12,400 --> 00:47:19,560
AND WHERE DO THESE MOLECULES

1376
00:47:19,560 --> 00:47:20,080
COME FROM?

1377
00:47:20,080 --> 00:47:21,000
>>SURE.

1378
00:47:21,000 --> 00:47:31,240
I DON'T KNOW.

1379
00:47:33,040 --> 00:47:34,200
[LAUGHTER]

1380
00:47:34,200 --> 00:47:38,400
GABBA RECEPTORS AND NICOTINIC

1381
00:47:38,400 --> 00:47:40,000
RECEPTORS HAVEN'T BEEN

1382
00:47:40,000 --> 00:47:41,520
MAINTAINED FOR THOSE SITES THAT

1383
00:47:41,520 --> 00:47:42,680
WE SINGICIZED BUT THOSE SITE

1384
00:47:42,680 --> 00:47:44,840
WHEN IS THEY'RE NOT ACPYING THEM

1385
00:47:44,840 --> 00:47:48,720
ARE CERTAINLY OCCUPIED BY LIPIDS

1386
00:47:48,720 --> 00:47:51,160
AND NEUROSTEROIDS ARE THINGS FOR

1387
00:47:51,160 --> 00:47:54,200
EXAMPLE, GABBA A RECEPTORS THAT

1388
00:47:54,200 --> 00:47:55,240
POTENT, IMPORTANT, ENDOGENOUS

1389
00:47:55,240 --> 00:47:56,640
MODULATORS AND OTHER

1390
00:47:56,640 --> 00:47:57,520
CHOLESTEROL, PROBABLY DOING THE

1391
00:47:57,520 --> 00:48:02,920
SAME THING IN BOTH THE GABBAA

1392
00:48:02,920 --> 00:48:04,480
RECEPTOR, NICOTINIC RECEPTOR AND

1393
00:48:04,480 --> 00:48:05,400
ANYONE'S FAVORITE CHANNEL SO

1394
00:48:05,400 --> 00:48:07,240
THESE, YOU KNOW MAYBE THE ANSWER

1395
00:48:07,240 --> 00:48:10,360
IS PARTLY THAT THESE COMPOUNDS

1396
00:48:10,360 --> 00:48:12,200
ARE--WELL THEY'RE CERTAINLY

1397
00:48:12,200 --> 00:48:13,240
REPLACING LIPIDS, WHAT LIPIDS

1398
00:48:13,240 --> 00:48:14,400
ARE DOING, YOU KNOW MORE WITH

1399
00:48:14,400 --> 00:48:16,400
THE DIFFERENT KIND OF ACTIVITY,

1400
00:48:16,400 --> 00:48:21,160
BUT I'M NOT ANSWERING YOUR

1401
00:48:21,160 --> 00:48:21,520
QUESTION.

1402
00:48:21,520 --> 00:48:22,800
>>TO SOME EXTENT YOU ARE

1403
00:48:22,800 --> 00:48:24,760
BECAUSE IT MAKES YOU THINK ABOUT

1404
00:48:24,760 --> 00:48:26,560
IT, AND THE AGONIST BUT ARE

1405
00:48:26,560 --> 00:48:30,000
THERE--IF YOU LOOK AT THE

1406
00:48:30,000 --> 00:48:31,600
NONSYSTEM RECEPTORS, DO THE

1407
00:48:31,600 --> 00:48:33,520
DRUGS AFFECT THEM TOO OR JUST

1408
00:48:33,520 --> 00:48:34,240
THE RECEPTORS?

1409
00:48:34,240 --> 00:48:39,080
>>YEAH, SOME OF THEM DO.

1410
00:48:39,080 --> 00:48:40,960
SO, THERE ARE POTASSIUM CHANNELS

1411
00:48:40,960 --> 00:48:44,320
THAT ARE AFFECTED BY THESE

1412
00:48:44,320 --> 00:48:45,520
DRUGS, NMDA RECEPTORS ARE A

1413
00:48:45,520 --> 00:48:47,120
MAJOR TARGET OF SOME OF THESE

1414
00:48:47,120 --> 00:48:47,320
DRUGS.

1415
00:48:47,320 --> 00:48:50,480
AND THEN IT'S A QUESTION OF IS

1416
00:48:50,480 --> 00:48:52,240
THE CONCENTRATION ARRANGED

1417
00:48:52,240 --> 00:48:53,640
THAT'S HITTING THE KINASEIS ARE

1418
00:48:53,640 --> 00:48:54,920
ACTIVATED OR MODULATES BY SOME

1419
00:48:54,920 --> 00:48:58,920
OF THE GENERAL ANESTHETICS

1420
00:48:58,920 --> 00:49:00,080
ESPECIALLY THE VOLATILE

1421
00:49:00,080 --> 00:49:01,280
ANESTHETICS ARE LIKE HOW THOSE

1422
00:49:01,280 --> 00:49:02,600
WORK, THEY DO ALL KINDS OF

1423
00:49:02,600 --> 00:49:04,400
THINGS TO ALL KINDS OF PROTEINS.

1424
00:49:04,400 --> 00:49:06,880
SO IT'S NOT A--OH IT'S

1425
00:49:06,880 --> 00:49:07,920
INHIBITING THIS CHANNEL AND

1426
00:49:07,920 --> 00:49:09,120
THAT'S DOING WHAT IT DOES IS NOT

1427
00:49:09,120 --> 00:49:12,240
THE WAY TO LOOK AT IT.

1428
00:49:12,240 --> 00:49:14,360
YEAH.

1429
00:49:14,360 --> 00:49:17,400
>>THANKS.

1430
00:49:17,400 --> 00:49:18,080
THANK YOU.

1431
00:49:18,080 --> 00:49:19,640
>>BEAUTIFUL TALK.

1432
00:49:19,640 --> 00:49:21,760
TWO QUESTIONS.

1433
00:49:21,760 --> 00:49:26,840
SO THE D-TUBO, THE NEW SITE, YOU

1434
00:49:26,840 --> 00:49:29,840
DIDN'T SHOW THE D-TUBO MODEL IN

1435
00:49:29,840 --> 00:49:32,160
THERE SO I'M GUESSING YOU DON'T

1436
00:49:32,160 --> 00:49:34,200
HAVE THE MODEL DENSITY TO MODEL

1437
00:49:34,200 --> 00:49:35,320
IT CANNED WHAT?

1438
00:49:35,320 --> 00:49:36,360
IS THAT RIGHT?

1439
00:49:36,360 --> 00:49:37,680
>>IT'S ACTUALLY QUITE
GOOD, THE

1440
00:49:37,680 --> 00:49:39,080
DENSITY IS QUITE GOOD.

1441
00:49:39,080 --> 00:49:42,360
WE DID MODEL IS IT.

1442
00:49:42,360 --> 00:49:44,560
IT'S BETTER THAT THE LOWER

1443
00:49:44,560 --> 00:49:48,080
AFFINITY EXTRA CELLULAR DOMAIN

1444
00:49:48,080 --> 00:49:48,320
SITE.

1445
00:49:48,320 --> 00:49:50,440
>>SO IS IT DEMONSTRATING
A

1446
00:49:50,440 --> 00:49:53,200
HYDROPHOBIC INTO THE BILAYER AND

1447
00:49:53,200 --> 00:49:54,360
THAT'S--

1448
00:49:54,360 --> 00:49:55,320
>>YES, YES, YES.

1449
00:49:55,320 --> 00:49:56,240
>>DOING IT?

1450
00:49:56,240 --> 00:49:56,520
>>YES.

1451
00:49:56,520 --> 00:49:58,360
>>SO THE SECOND QUESTION
WAS

1452
00:49:58,360 --> 00:50:00,120
THE TOXIN STRUCTURE, I COULD BT

1453
00:50:00,120 --> 00:50:02,280
HAPPEN THINKING, LOOKINGA THE

1454
00:50:02,280 --> 00:50:03,640
STRUCTURE AND HOW EXTRACTING

1455
00:50:03,640 --> 00:50:05,040
SENTIA WILY THE TOXIN IS

1456
00:50:05,040 --> 00:50:06,280
ESSENTIALLY WHAT IT'S ENGAGING

1457
00:50:06,280 --> 00:50:09,640
TO THE RECEPTOR, CAN YOU USE

1458
00:50:09,640 --> 00:50:11,520
THAT TO NOW, FOR A MINIMAL

1459
00:50:11,520 --> 00:50:13,720
VERSION OF THE TOXIN THAT THE IT

1460
00:50:13,720 --> 00:50:16,120
WILL ESSENTIALLY TRIM IT DOWN TO

1461
00:50:16,120 --> 00:50:16,840
WHAT YOU NEED?

1462
00:50:16,840 --> 00:50:18,440
HAVE YOU EVER THOUGHT ABOUT

1463
00:50:18,440 --> 00:50:18,680
THAT?

1464
00:50:18,680 --> 00:50:21,120
>>PEOPLE HAVE DONE THAT.

1465
00:50:21,120 --> 00:50:21,360
YEAH.

1466
00:50:21,360 --> 00:50:23,440
THERE ARE--YOU CAN TAKE THAT--I

1467
00:50:23,440 --> 00:50:24,760
DON'T KNOW, I FORGET HOW MANY

1468
00:50:24,760 --> 00:50:26,080
RESIDUES BUT IT'S NOT VERY MUCH,

1469
00:50:26,080 --> 00:50:28,040
SOMETHING LIKE, I DON'T KNOW 10

1470
00:50:28,040 --> 00:50:29,440
OR 12 RESIDUES OF THE TIP OF THE

1471
00:50:29,440 --> 00:50:31,920
LOOP AND TELL BIND AND INHIBIT.

1472
00:50:31,920 --> 00:50:32,640
YEAH.

1473
00:50:32,640 --> 00:50:33,040
>>THANK YOU.

1474
00:50:33,040 --> 00:50:37,840
>>YEAH, YEAH.

1475
00:50:37,840 --> 00:50:40,040
>>RYAN 1 OF THE THINGS
THAT'S

1476
00:50:40,040 --> 00:50:41,680
PUZZLED ME ABOUT YOUR ALPHA 7

1477
00:50:41,680 --> 00:50:42,920
STRUCTURE AND I DIDN'T REALIZE

1478
00:50:42,920 --> 00:50:48,920
THAT THIS IS THE SAME THERE IN

1479
00:50:48,920 --> 00:50:50,120
THE NICKEE TEENIC RECEPTORS AS

1480
00:50:50,120 --> 00:50:53,000
WELL, HAVE YOU THE GLUTAMATE,

1481
00:50:53,000 --> 00:50:54,680
DID YOU SEE EVIDENCE OF CAN THE

1482
00:50:54,680 --> 00:50:55,920
WHAT ON THAT?

1483
00:50:55,920 --> 00:50:57,480
>>YEAH, RIGHT.

1484
00:50:57,480 --> 00:51:01,600
SO IN THE MUSCLE NICOTINIC, SO

1485
00:51:01,600 --> 00:51:04,280
THE VERY BOTTOM OF THE ION

1486
00:51:04,280 --> 00:51:06,040
CHANNEL CONTAINS DEPENDING ON

1487
00:51:06,040 --> 00:51:09,240
THE RECEPTOR TYPE MOSTLY OR

1488
00:51:09,240 --> 00:51:10,000
EXCLIEWKSIVELY GLUTAMATE SIDE

1489
00:51:10,000 --> 00:51:11,480
CHAINS SO THEY FORM A RING AT

1490
00:51:11,480 --> 00:51:13,680
THE BOTTOM, AND THEY ARE THE

1491
00:51:13,680 --> 00:51:15,520
MAJOR DETERMINE NABT OF CAT ION

1492
00:51:15,520 --> 00:51:16,200
SELECTIVITY.

1493
00:51:16,200 --> 00:51:17,000
IF YOU NEUTRALIZE THOSE OR

1494
00:51:17,000 --> 00:51:18,080
SELECT THE CHARGE, CAN YOU

1495
00:51:18,080 --> 00:51:20,040
SELECT THE CHANNEL TO AN ION

1496
00:51:20,040 --> 00:51:22,160
SELECTIVITY IN SOME CASES IT'S

1497
00:51:22,160 --> 00:51:23,520
THAT SIMPLE SOPHISTICATEDY

1498
00:51:23,520 --> 00:51:24,600
WHAT'S HAPPENING TO THOSE SIDE

1499
00:51:24,600 --> 00:51:26,040
CHAINS IN THE DESENSITIZED STATE

1500
00:51:26,040 --> 00:51:27,280
OR THE RESTING STATE OR

1501
00:51:27,280 --> 00:51:27,560
WHATEVER.

1502
00:51:27,560 --> 00:51:30,920
AND WHAT WE SEE IN THE TORPEDO

1503
00:51:30,920 --> 00:51:32,280
RECEPTOR IS THAT, THEY ACTUALLY

1504
00:51:32,280 --> 00:51:34,640
ROTATE AWAY FROM THE CENTRAL

1505
00:51:34,640 --> 00:51:35,960
AXIS AND THESE NONCONDUCTING

1506
00:51:35,960 --> 00:51:37,600
STATES AND THEY CAP THE END TERM

1507
00:51:37,600 --> 00:51:42,240
NIGH OF THE HELIXES OF THE

1508
00:51:42,240 --> 00:51:43,400
ADJACENT SUBUNITS.

1509
00:51:43,400 --> 00:51:46,920
SO THESE BUILD UP IN-CHARGESOT

1510
00:51:46,920 --> 00:51:49,120
THEY'RE POSITIVE PARTIAL CHARGES

1511
00:51:49,120 --> 00:51:50,960
AND PARTIAL NEGATIVE CHARGES AND

1512
00:51:50,960 --> 00:51:52,960
THESE HELIXES LIKE TO BE

1513
00:51:52,960 --> 00:51:54,560
STABILIZED BY CAPPING

1514
00:51:54,560 --> 00:51:56,520
INTERACTIONS AND LOGICAL THAT

1515
00:51:56,520 --> 00:51:58,000
NEGATIVELY CHARGED SED CHAIN

1516
00:51:58,000 --> 00:52:00,080
WOULD CAP THE END TERMINUS,

1517
00:52:00,080 --> 00:52:01,920
THAT'S WHAT WE SEE.

1518
00:52:01,920 --> 00:52:03,680
VERY STABLE, VERY CLEAR DENSITY.

1519
00:52:03,680 --> 00:52:05,400
SO IN ALPHA 7, THE DENSITY IN

1520
00:52:05,400 --> 00:52:07,120
THE EARLIER STRUCTURES WE

1521
00:52:07,120 --> 00:52:08,840
PUBLISHED, THE DENSITY FOR THOSE

1522
00:52:08,840 --> 00:52:10,200
SED CHAINS YOU COULDN'T SEE THEM

1523
00:52:10,200 --> 00:52:12,240
REALLY MAYBE YOU COULD SEE

1524
00:52:12,240 --> 00:52:15,040
DENSITY FOR 1, AND IN THAT CASE,

1525
00:52:15,040 --> 00:52:17,440
EITHER THAT WAS JUST LOCALLY BAD

1526
00:52:17,440 --> 00:52:18,280
OR POOR RESOLUTION, OR WHAT

1527
00:52:18,280 --> 00:52:20,000
THEY'RE DOING IS THIS, AND

1528
00:52:20,000 --> 00:52:22,480
THEY'RE ADOPTING MULTIPLE

1529
00:52:22,480 --> 00:52:23,200
CONFIRMATIONS, AND IT DOESN'T

1530
00:52:23,200 --> 00:52:26,720
MAKE SENSE TO ME THAT THEY WOULD

1531
00:52:26,720 --> 00:52:28,600
BE FORMING A DESENSITIZATION

1532
00:52:28,600 --> 00:52:30,680
GATED UNLESS, WHAT YOU'RE DOING

1533
00:52:30,680 --> 00:52:32,200
IS KEYALATING SOME SOMETHING

1534
00:52:32,200 --> 00:52:32,800
LIKE CALCIUM, RIGHT?

1535
00:52:32,800 --> 00:52:40,600
DOWN IN THE RING AND WE DO SEE

1536
00:52:40,600 --> 00:52:43,960
IN ALPHA 3 FOR 4, AND WHEN WE

1537
00:52:43,960 --> 00:52:51,160
ADD DDTA, WE CAN DEPLETE 1 OF

1538
00:52:51,160 --> 00:52:53,120
THOSE SITES AND SO AS WE KNOW,

1539
00:52:53,120 --> 00:52:55,120
CALCIUM DOES ALL KINDS OF

1540
00:52:55,120 --> 00:52:57,760
THINGS, THERE'S USUALLY A

1541
00:52:57,760 --> 00:52:59,080
POSITIVE MODLATTORY EFFECT AND

1542
00:52:59,080 --> 00:53:02,280
THE OTHER SUBTYPES CALCIUM, CAN

1543
00:53:02,280 --> 00:53:03,280
INCREASE THE--INCREASE IN

1544
00:53:03,280 --> 00:53:04,440
CALCIUM CONCENTRATION CAN

1545
00:53:04,440 --> 00:53:05,080
INCREASE THE DESENSITIZATION

1546
00:53:05,080 --> 00:53:05,520
RATE AS WELL.

1547
00:53:05,520 --> 00:53:08,880
SO IT COULD BE DOING THAT BY

1548
00:53:08,880 --> 00:53:09,480
STABILIZING THESE GLUTAMATES

1549
00:53:09,480 --> 00:53:12,520
ORIENTED INTO THE CENTRALAXIS,

1550
00:53:12,520 --> 00:53:13,480
THERE'S PIECES THAEVER ARE

1551
00:53:13,480 --> 00:53:22,880
COMING TOGETHER, IT'S A LOGICAL

1552
00:53:22,880 --> 00:53:23,120
IDEA.

1553
00:53:23,120 --> 00:53:24,080
>>O A RELATED FOLLOW UP
AND

1554
00:53:24,080 --> 00:53:26,080
IT'S GOOD TO BE THE CONTROVERSY

1555
00:53:26,080 --> 00:53:27,560
OF THE POLAR GATE AND WHETHER OR

1556
00:53:27,560 --> 00:53:30,440
NOT IT'S LEAKING IS STILL VERY

1557
00:53:30,440 --> 00:53:37,440
MUCH RAGING THAT'S EXCITING I

1558
00:53:37,440 --> 00:53:38,760
WAS WONDERING WHY, IF YOU THINK

1559
00:53:38,760 --> 00:53:40,240
YOU COULD GIVE MORE INFORMATION

1560
00:53:40,240 --> 00:53:42,040
ABOUT THE PROXIMITY IN THE

1561
00:53:42,040 --> 00:53:43,160
BOTTOM PART WHICH DOESN'T SEEM

1562
00:53:43,160 --> 00:53:48,560
TO BE CHANGING IN ANY OF YOUR

1563
00:53:48,560 --> 00:53:48,880
MODELS.

1564
00:53:48,880 --> 00:53:51,720
DOES 1 GET INFORMATION ON

1565
00:53:51,720 --> 00:53:54,000
WHATEVER PERMEABILITY THERE IS

1566
00:53:54,000 --> 00:54:03,200
BY LOOKING AT THESE DIFFERENT

1567
00:54:03,200 --> 00:54:04,280
REAGENTS [INDISCERNIBLE]?

1568
00:54:04,280 --> 00:54:05,360
>>YEAH, SORT OF A HOW CAN
WE

1569
00:54:05,360 --> 00:54:11,680
HAVE A RULER FOR WHAT THOSE ARE

1570
00:54:11,680 --> 00:54:13,320
USING SOME ORTHOGONAL APPROACH

1571
00:54:13,320 --> 00:54:14,440
THAT'S NOT STRUCTURAL BIOLOGY.

1572
00:54:14,440 --> 00:54:14,840
I DON'T KNOW.

1573
00:54:14,840 --> 00:54:16,640
IF YOU DON'T HAVE A CONDUCTING

1574
00:54:16,640 --> 00:54:18,080
CHANNEL, YOU CAN'T MEASURE THE

1575
00:54:18,080 --> 00:54:20,800
SIZE OF WHAT'S GOING THROUGH

1576
00:54:20,800 --> 00:54:21,880
BECAUSE NOTHING'S GOING THROUGH,

1577
00:54:21,880 --> 00:54:25,840
I DON'T KNOW, I MEAN.

1578
00:54:25,840 --> 00:54:27,200
>>IT'S NOT NOTHING,
THAT'S

1579
00:54:27,200 --> 00:54:28,840
RIGHT, IT'S GOOD TOO BUT THE

1580
00:54:28,840 --> 00:54:33,400
STUDIES WITH THESE PERMEATION

1581
00:54:33,400 --> 00:54:34,200
SERIES S&POOSE NOT LIKE ONCE
YOU

1582
00:54:34,200 --> 00:54:36,320
GOET TO 7 AND HALF ANGSTROMS IT

1583
00:54:36,320 --> 00:54:38,560
GOES TO FULLY CONDUCTING 0, IT

1584
00:54:38,560 --> 00:54:39,760
TAPERS OFF AND THEY HAVE SOME

1585
00:54:39,760 --> 00:54:41,640
WAY OF SAYING OKAY, THIS IS THEN

1586
00:54:41,640 --> 00:54:52,080
THE DIAMETER THAT I DIDN'T

1587
00:54:53,080 --> 00:54:54,680
UNDERSTAND, YEAH ALL WE'VE BEEN

1588
00:54:54,680 --> 00:54:58,240
DOING IS LOOKING AT SIMULATIONS

1589
00:54:58,240 --> 00:54:59,800
GROUPS WITH ERIC MENDALL'S

1590
00:54:59,800 --> 00:55:01,800
GROUPS AND CAN WE CORRELATE IT?

1591
00:55:01,800 --> 00:55:03,800
IT MAKES SENSE BUT STILL MESSY.

1592
00:55:03,800 --> 00:55:09,600
>>JUST A FOLLOW UP ON
THAT

1593
00:55:09,600 --> 00:55:10,480
ISSUES THE POTASSIUM CHANNELS

1594
00:55:10,480 --> 00:55:12,920
WHERE THERE'S MULTILE FORMS OF

1595
00:55:12,920 --> 00:55:14,880
ACTIVATION, THERE IS' 1 OF THE

1596
00:55:14,880 --> 00:55:20,200
CORE, DILATES THE FILTER AND

1597
00:55:20,200 --> 00:55:20,720
DIMINISHES POTASSIUM BUT

1598
00:55:20,720 --> 00:55:23,480
INCREASES TOADIUM SO THERE ARE

1599
00:55:23,480 --> 00:55:25,640
PARALLELS, SO FURTHER IN THAT

1600
00:55:25,640 --> 00:55:27,400
THE OTHER QUESTION I HAVE IF YOU

1601
00:55:27,400 --> 00:55:37,720
GOES IT KIND OFIOURE

1602
00:55:44,280 --> 00:55:45,160
INTERPRETATIONS ABOUT IT SEEPS

1603
00:55:45,160 --> 00:55:47,680
LIKE ALL YOUR LIGANDS HAVE SOME

1604
00:55:47,680 --> 00:55:49,520
PROBABILITY OF COURSE AND YOU'RE

1605
00:55:49,520 --> 00:55:55,960
NO LONGER, YOU KNOW DEALING WITH

1606
00:55:55,960 --> 00:55:57,640
THE MEMBRANE BUT I WAS CURIOUS

1607
00:55:57,640 --> 00:55:59,040
ABOUT THAT?

1608
00:55:59,040 --> 00:56:01,240
>>YEAH, DIFFERENT PEOPLE
IN THE

1609
00:56:01,240 --> 00:56:03,400
FIELD HAVE INTERPRETED THIS IN

1610
00:56:03,400 --> 00:56:05,120
DIFFERENT WAYS.

1611
00:56:05,120 --> 00:56:08,040
HIEWBENER READ, AND THEY HAD AN

1612
00:56:08,040 --> 00:56:10,280
AGONIST BOUND STATE THAT BASED

1613
00:56:10,280 --> 00:56:11,680
ON ELECTROPHYSIOLOGY WE WOULD

1614
00:56:11,680 --> 00:56:13,720
SAY THEY WOULD ALSO SAY THIS

1615
00:56:13,720 --> 00:56:15,120
SHOULD BE DESENSITIZED BUT THEY

1616
00:56:15,120 --> 00:56:16,560
DO MD AND THEY SEE IT'S LEAKY

1617
00:56:16,560 --> 00:56:19,560
AND THEY SAY MAYBE IT'S A

1618
00:56:19,560 --> 00:56:20,320
PREOPEN STATE.

1619
00:56:20,320 --> 00:56:22,720
THE PREOPEN STATE SHOULD NOT

1620
00:56:22,720 --> 00:56:24,520
REALLY BE POPULATED IN A REAL

1621
00:56:24,520 --> 00:56:25,800
MEMBRANE, BUT WE HAVE RIPPED

1622
00:56:25,800 --> 00:56:27,760
THIS THRING OUT OF THE MEMBRANE

1623
00:56:27,760 --> 00:56:29,760
WITH DETERGENT AND THEN

1624
00:56:29,760 --> 00:56:31,600
RECONSITUTE IT INTO NANO DISKS

1625
00:56:31,600 --> 00:56:32,840
AND EVERY SCAFFOLD YOU USE WILL

1626
00:56:32,840 --> 00:56:37,360
HAVE SOME EFFECT ON

1627
00:56:37,360 --> 00:56:46,760
CONFIRMATIONALLY EQUILIBRIUM 2. 

1628
00:56:46,760 --> 00:56:48,760
>>SO--

1629
00:56:48,760 --> 00:56:49,240
>>WHAT?

1630
00:56:49,240 --> 00:56:52,360
>>[INDISCERNIBLE] REOPEN
STATE

1631
00:56:52,360 --> 00:56:53,880
DOES EXIST NORMALLY?

1632
00:56:53,880 --> 00:56:56,400
>>THE REOPEN STATE EXISTS
WHAT?

1633
00:56:56,400 --> 00:56:57,800
>>DOES EXIST.

1634
00:56:57,800 --> 00:56:58,760
>>DOES EXIST.

1635
00:56:58,760 --> 00:56:59,360
YEAH.

1636
00:56:59,360 --> 00:57:00,840
I THINK THE PREOPEN STATE EXISTS

1637
00:57:00,840 --> 00:57:02,960
BUT WHETHER YOU WOULD EXPECT IT

1638
00:57:02,960 --> 00:57:05,000
TO BE ABUNDANT YOU SHOULD

1639
00:57:05,000 --> 00:57:05,480
SATURATING AGONIST

1640
00:57:05,480 --> 00:57:08,600
CONCENTRATION, I DON'T KNOW,

1641
00:57:08,600 --> 00:57:08,920
YEAH; YEAH.

1642
00:57:08,920 --> 00:57:10,800
>>THAT WAS REALLY
BEAUTIFUL, I

1643
00:57:10,800 --> 00:57:11,920
AM INTERESTED IN THE PARTICLES

1644
00:57:11,920 --> 00:57:14,640
THAT YOU THROW AWAY, BECAUSE THE

1645
00:57:14,640 --> 00:57:18,440
HELIXES ON THE INSIDE ARE NOT

1646
00:57:18,440 --> 00:57:20,640
VISIBLE, ARE THEY VISIBLE, IS IT

1647
00:57:20,640 --> 00:57:21,800
POSSIBLE IF YOU ACTUALLY

1648
00:57:21,800 --> 00:57:23,320
CLASSIFY THEM IN LOOK INTO THE

1649
00:57:23,320 --> 00:57:24,960
THEM IN MORE DETAILS THAT THE

1650
00:57:24,960 --> 00:57:26,680
HELIXES ARE RUNNING PARALLEL TO

1651
00:57:26,680 --> 00:57:29,600
THE SURFACE OF THE NANO DISK AND

1652
00:57:29,600 --> 00:57:32,720
ON THE MEMBRANE LIKE LITERALLY

1653
00:57:32,720 --> 00:57:34,040
CHANGING CONFIRMATION RATHER

1654
00:57:34,040 --> 00:57:34,520
THAN DISAPPEARING?

1655
00:57:34,520 --> 00:57:35,880
HAVE YOU CONSIDERED THAT.

1656
00:57:35,880 --> 00:57:38,280
>>OH, I EXPECT THAT IN
REALITY

1657
00:57:38,280 --> 00:57:39,480
THEY ARE THAT THEY DO SOMETHING

1658
00:57:39,480 --> 00:57:43,600
LIKE THAT BUT IN A WAY THAT

1659
00:57:43,600 --> 00:57:44,720
VARIES FROM PARTICLE TO

1660
00:57:44,720 --> 00:57:45,000
PARTICLE.

1661
00:57:45,000 --> 00:57:45,880
SO THEY AVERAGE OUT.

1662
00:57:45,880 --> 00:57:47,800
WE HAVE TRIED TO INCLUDING THOSE

1663
00:57:47,800 --> 00:57:49,520
PARTICLES IN OVERALL REFINEMENT

1664
00:57:49,520 --> 00:57:51,360
AND REFINING THAT SUBSET AND WE

1665
00:57:51,360 --> 00:57:53,560
GET THE EXACT SAME CONFIRMATION

1666
00:57:53,560 --> 00:57:55,080
THAT'S PRESENT WHEN THE

1667
00:57:55,080 --> 00:57:57,160
INTRACELLULAR DOMAIN IS THERE,

1668
00:57:57,160 --> 00:57:59,880
JUST MISSING THE INTRACELLULAR

1669
00:57:59,880 --> 00:58:02,880
DOMAIN; YEAH.

1670
00:58:02,880 --> 00:58:03,120
>>YEAH.

1671
00:58:03,120 --> 00:58:06,320
>>ALL RIGHT, THANK YOU
ALL SO

1672
00:58:06,320 --> 00:00:00,000
MUCH.