Voltage-gated Nat channels )Many flavors >nerves, glia, heart, skeletal muscle >Primary role is action potential initiation >Multi-subunit channels(300 kDa) Skeletal Na* Channel: a(260 kDa) and B,(36kDa) Nerve nat channel:α1β1,β2(33kDa) gating/permeation machinery in a, subunits Three types of conformational states(close open or activation, inactivation)-each controlled by membrane voltage39 Voltage-gated Na+ Channels ➢ Many flavors ➢nerves, glia, heart, skeletal muscle ➢ Primary role is action potential initiation ➢ Multi-subunit channels (~300 kDa) ➢Skeletal Na+ Channel: a1 (260 kDa) and b1 (36kDa) ➢Nerve Na+ Channel: a1 , b1 , b2 (33 kDa) ➢gating/permeation machinery in a1 subunits ➢ Three types of conformational states (close, open or activation, inactivation) - each controlled by membrane voltage