Lesson 16: Gated Channels

voltage gated membrane channel structure

multiple subunits, each with 6 transmembrane helices

S5 & S6 helices of voltage gated channel

line pore and confer selectivity

S4 helix of voltage gated channel

voltage sensor; contains many charged residues

intracellular N-terminus of voltage gated channel

inactivation domain (ball and chain)

Cys-loop channels

2 Cys on extracellular N-terminus form disulfide bond (Cys loop)

Glutamate / P pore loop channels

gated by glutamate

P2X channels

gated by ATP

Cys-loop channel structure

"pentamers (2𝛼, β, γ and δ) w/ 4 transmembrane segments each

"

nAChR is a (channel type)

Cys-loop channel

glutamate channel structure

tetramers w/ 3 transmembrane segments each

P2X channel structure

trimers w/ 2 transmembrane segments each

AChE

acetylcholine esterase; breaks down ACh in synaptic cleft

ChAT

choline acetyltransferase; synthesizes ACh from choline and acetyl CoA

NMBAs

neuromuscular blocking agents; competitive ACh antagonists