Physical Mechanisms for ion-current levelling off in the KcsA channel through combined Monte Carlo/Molecular Dynamics simulations

Conduction and noise properties of potassium ions in the KcsA membrane channel are analysed by means of a combined Molecular Dynamics-Monte Carlo numerical approach. The high-voltage part of the experimental I(V) charac-teristics shows a tendency to level off which is reproduced by computational re-sults using a conduction model quite sensitive to the particular set of transition probabilities among the relevant ion occupancy configurations. Noise power spec-tra confirm the existence of correlation between consecutive ion exits from the channel.