Electrostatic Influence on Ion Transport through the alpha HL Channel

Published

October 1, 2003

Author(s)

M Misakian, John J. Kasianowicz

Abstract

The current-voltage relationship of a single Staphylococcus aureus α-hemolysin(αHL) channel is nonlinear, rectifying, and depends on the bulk pH and the ionic strength. The data are described qualitatively by a simple one-dimensional Nernst-Planck analysis in which the fixed charges inside and near the pore's entrances control the transport of ions through the channel. The distances of these fixed charges from one of the channel's entrances are obtained from the channel's crystal structure. The model demonstrates that rectification fo monovalent ion flow through the αHL channel can be related to the asymmetry in the location of the ionizable amino acid side chains. This result is in good agreement with the previously observed asymmetric partitioning of polynucleotides into the channel.

Citation

Journal of Membrane Biology

Volume

195

Issue

3

Pub Type

Journals

Keywords

alpha hemolysin, alpha toxin, electrostatics, ion channel, Nernst-Planck analysis

Citation

Misakian, M. and Kasianowicz, J. (2003), Electrostatic Influence on Ion Transport through the alpha HL Channel, Journal of Membrane Biology (Accessed October 8, 2025)