A BROWNIAN DYNAMICS STUDY OF DIRECT ION PASSAGE THROUGH POTASSIUM CHANNEL

Direct passage of alkali metal cations K, Na, Li, Cs, Rb through a model transmembrane potassium channel is simulated by means of the Brownian dynamic technique. The Langevin version of the Brownian motion in the diffusive limit and with finite difference equation approximation was used. Ion trajectories, single channel unidirectional ionic fluxes and conductivities, as well as average times of direct passage were calculated. The microscopic theory of channel selectivity is presented.