Determination of the charge profile in the KcsA selectivity filter using ab initio calculations and molecular dynamics simulations

The charge pro. le of K(+) and Na(+) ions moving in a single. le across the filter of the KcsA channel is determined using both molecular dynamics simulations and ab initio calculations. We show a strong correlation between the charge variation and the ion location resulting in a saw-tooth pro. le, which provides additional information on the influence of charge transfer on the permeation and selectivity of the channel.