Noise properties of single open ion channels: an atomistic computational approach

This paper presents the first results of a computational analysis of the noise associated with ion current in single open ion channels. This analysis is performed by means of a coupled Molecular Dynamics-Monte Carlo approach able to simulate the conduction process on the basis of all microscopic information today available from protein structural data and atomistic simulations. The case of potassium ions permeating the KcsA channel is considered in the numerical calculations. The obtained results evidence a noise spectrum different from what is theoretically predicted for uncorrelated ion-exit events (Poisson noise), confirming the existence of correlation in ion motion within the channel.