2011
Volume 11, Number 1, p.p. 6–10
Memory effects in the fast substates system of alamethicin channels
P.A. Grigoriev
Institute of Cell Biophysics, Russian Academy of Science, Pushchino, 142290 Moscow Region, Russia
Conducting substates of the ion channel formed by the polypeptide antibiotic alamethicin in lipid bilayers were studied. It is shown that all distributions of the substate dwell times contain in addition to a slow exponent a high amplitude fast one. After entering a state with a new conductance the channel “remembers” during about 50 ms the previous state and there is a high probability of the channel returning back to this previous conductance state. The effect is explained with the proposal that each conductance state is an assembly of one state with a long lifetime and at least two short dwell time substates. It is shown that any change of the channel conductance is a result of a transition in the system of substates with short dwell time.