Multiple intermediate states precede pore block during N-type inactivation of a voltage-gated potassium channel.

ABSTRACT: N-type inactivation of voltage-gated potassium channels is an autoinhibitory process that occurs when the N terminus binds within the channel pore and blocks conduction. N-type inactivation and recovery occur with single-exponential kinetics, consistent with a single-step reaction where binding and block occur simultaneously. However, recent structure-function studies have suggested the presence of a preinactivated state whose formation and loss regulate inactivation and recovery kinetics. Our studies on N-type inactivation of the Shaker-type AKv1 channel support a multiple-step inactivation process involving a series of conformational changes in distinct regions of the N terminus that we have named the polar, flex, and latch regions. The highly charged polar region forms interactions with

SUBMITTER: Prince-Carter A 

PROVIDER: S-EPMC2712980 | biostudies-literature | 2009 Jul

REPOSITORIES: biostudies-literature