Charge immobilization in two different fast-inactivation-removed Nav1.4 sodium channel mutants

Abstract

Fast inactivation is a key feature of voltage-gated sodium channels and is essential for action potential kinetics and recovery. One consequence of fast inactivation is the immobilization of gating charges of domains III and IV. It has been proposed that the closure of the fast inactivation gate would impede the movement of voltage sensors. As a result, a fraction of gating charges can only return to the resting state once fast inactivation is recovered, giving rise to the charge immobilization.