Strand 1 Flashcards
How is ion channel FUNCTION measured?
Patch clamp electrophysiology
How is ion channel STRUCTURE measured?
cryo electron microscopy or x ray crystallography
What toxin comes from the pufferfish and what does it do?
Tetratodoxin (TTX) - blocks sodium channel pores.
What toxin comes from death stalker scorpion and what does it do?
Charybdotoxin (CTX)
Blocks potassium channel pores (Shaker ion channel)
What toxin comes from Funnel-web spider and what does it do?
w-agatoxin
Blocks voltage sensor in calcium channel.
What is the other name for the Shaker channel?
KCNQ1 potassium channel
How can looking at amino acid structure help investigate ion channel structure?
Hydrophobic amino acids will form the transmembrane part of the channel, whilst hydrophilic/polar/charged amino acids will be the extra membrane part where ligands bind
In voltage gated ion channels, which domain is voltage sensing and which amino acids are found in this domain?
Domain 4. Has lysine and arginine residues which are positively charged.
How can ion channels be inactivated?
N type inactivation. The amino acids at the N terminal block the intracellular channel pore. This is rapid inactivation.
C type inactivation involves a conformational change at the extracellular part of the channel. This is slow inactivation.
What is the closest human homologue to the Sh gene in drosophila?
KCNA3
The RMP in neurones is -70mV. What is the maintained by?
Maintained by K+ flux through potassium leak channels and NA/K pump.
Which genes for VGSC are involved in pain?
SCN9A - subtype Na1.7
SCN11A - subtype Na1.9
Which genes for VGSC are involved in epilepsy and migraines?
SCN1A subtype Na1.1
