Referenced in: none

Automatically associated channels: Kv11.1

Title: Ion conduction through the hERG potassium channel.

Authors: Luisa Ceccarini, Matteo Masetti, Andrea Cavalli, Maurizio Recanatini

Journal, date & volume: PLoS ONE, 2012 , 7, e49017

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23133669

Abstract
The inward rectifier voltage-gated potassium channel hERG is of primary importance for the regulation of the membrane potential of cardiomyocytes. Unlike most voltage-gated K(+)-channels, hERG shows a low elementary conductance at physiological voltage and potassium concentration. To investigate the molecular features underlying this unusual behavior, we simulated the ion conduction through the selectivity filter at a fully atomistic level by means of molecular dynamics-based methods, using a homology-derived model. According to our calculations, permeation of potassium ions can occur along two pathways, one involving site vacancies inside the filter (showing an energy barrier of about 6 kcal mol(-1)), and the other characterized by the presence of a knock-on intermediate (about 8 kcal mol(-1)). These barriers are indeed in accordance with a low conductance behavior, and can be explained in terms of a series of distinctive structural features displayed by the hERG ion permeation pathway.