Non-equilibrium dynamics contribute to ion selectivity in the KcsA channel.

ABSTRACT: The ability of biological ion channels to conduct selected ions across cell membranes is critical for the survival of both animal and bacterial cells. Numerous investigations of ion selectivity have been conducted over more than 50 years, yet the mechanisms whereby the channels select certain ions and reject others are not well understood. Here we report a new application of Jarzynski's Equality to investigate the mechanism of ion selectivity using non-equilibrium molecular dynamics simulations of Na(+) and K(+) ions moving through the KcsA channel. The simulations show that the selectivity filter of KcsA adapts and responds to the presence of the ions with structural rearrangements that are different for Na(+) and K(+). These structural rearrangements facilitate entry of K(+) ions into th

SUBMITTER: Ngo V 

PROVIDER: S-EPMC3895005 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature