Referenced in: none

Automatically associated channels: Kir2.3

Title: Modelling the activation, opening, inactivation and reopening of the voltage-gated sodium channel.

Authors: R D Keynes, F Elinder

Journal, date & volume: Proc. Biol. Sci., 1998 Feb 22 , 265, 263-70

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/9523428

Abstract
A model of the voltage-gated sodium channel is put forward suggesting that the four S4 voltage-sensors behave as screw-helices making a series of discrete transitions that carry one elementary charge for each notch of the screw helix. After the channel has been activated by the first two steps R in equilibrium with P in equilibrium with A in all four domains, followed by a voltage-independent rearrangement, it is opened by a third cooperative step A in equilibrium with B in domains I, II and III in conjunction with hydration. Inactivation is a voltage-dependent process controlled by the third step A in equilibrium with I in sensor IVS4, and the closing of the channel is brought about its dehydration. From the inactivated steady state the channel may be reopened by a fourth step, I in equilibrium with C in sensor IVS4 and rehydration. The computed kinetics of the model are shown to conform closely with those observed experimentally.