Thermodynamic coupling between activation and inactivation gating in potassium channels revealed by free energy molecular dynamics simulations.

ABSTRACT: The amount of ionic current flowing through K(+) channels is determined by the interplay between two separate time-dependent processes: activation and inactivation gating. Activation is concerned with the stimulus-dependent opening of the main intracellular gate, whereas inactivation is a spontaneous conformational transition of the selectivity filter toward a nonconductive state occurring on a variety of timescales. A recent analysis of multiple x-ray structures of open and partially open KcsA channels revealed the mechanism by which movements of the inner activation gate, formed by the inner helices from the four subunits of the pore domain, bias the conformational changes at the selectivity filter toward a nonconductive inactivated state. This analysis highlighted the important role of

SUBMITTER: Pan AC 

PROVIDER: S-EPMC3226968 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature