L04 Flashcards
what happens when Sh gene is mutated in drosophila
it results in shaking legs
what is disrupted in Sh mutation
repolarization
what are the methods of studying ion channels
patch clamp Electrophysiology
- investigates the function of an ion channel
(Cryo) Electron Microscopy OR X-ray crystallography
- investigates the structure of an ion channel
what are gated ion channels
Ion channels open/close in response to stimuli
what are the types of gated ion channels
voltage gated
ligand gated (extracellular ligand) (neurotransmitter-gated)
ligand gated (intracellular ligand) (ion-gated nucleotide-gated)
mechanically gated
what is tetrodotoxin (TTX) produced by Pufferfish
sodium channel blocker that blocks the pore
what is Charybdotoxin (CTX) produced by Deathstalker Scorpion
potassium channel blocker that blocks the pore
what is ω-agatoxin produced by Funnel-web spider
Calcium channel blocker (blocks voltage sensor)
what does the use of ion channel toxins help us test
Substrate selectivity
- the separate pathways for the flux of different ions
gating
- Control ion channel opening/closing
- Dynamic control
- Voltage/ signal/ ligand/stretch gated
what is shaker also known as
KCNQ1 Potassium Channel
what subunits does KCNQ1 Potassium Channel have
Alpha & beta subunits
how do you look at a protein structure
determine the structure experimentally e.g. X-ray crystallography
computational predictions
- accelerated by AI
what is the first thing to do when investigating the structure of an ion channel
1-Look at the amino acid sequence
2-using experimental methods
how does the amino acid sequence help predict the protein structure
Looking at the biochemical properties of specific amino acid side-chains
looking for conserved sequences
which part of the structure would have hydrophobic residues
transmembrane region
which part of the structure would have Polar/charged/hydrophilic residues
extramembrane, ligand binding etc.