Rectification of the current in alpha-hemolysin pore depends on the cation type: the alkali series probed by MD simulations and experiments.

ABSTRACT: A striking feature of the alpha-hemolysin channel-a prime candidate for biotechnological applications-is the dependence of its ionic conductance on the magnitude and direction of the applied bias. Through a combination of lipid bilayer single-channel recording and molecular dynamics (MD) simulations, we characterized the current-voltage relationship of alpha-hemolysin for all alkali chloride salts at neutral pH. The rectification of the ionic current was found to depend on the type of cations and increase from Li(+) to Cs(+). Analysis of the MD trajectories yielded a simple quantitative model that related the ionic current to the electrostatic potential, the concentration and effective mobility of ions in the channel. MD simulations reveal that the major contribution to the current asymmet

SUBMITTER: Bhattacharya S 

PROVIDER: S-EPMC3158494 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature