ION PORES IN BIOLOGICAL-MEMBRANES AS SELF-ORGANIZED BISTABLE SYSTEMS

It is shown that an ionic channel in biological membranes is a self-organized nonequilibrium dynamic system functioning in a multistable regime. The different components of such a regime can be compared with discrete conductivity levels of the ionic channel. For the case of a channel with two binding sites we have shown that such an effect is a consequence of organization of the conformational channel structure at the expense of the energy of an ion flux itself The possibility of the control of the channel functioning due to the external electric field is also considered. Calculations show that one may effectively modulate channel lifetimes in their open and closed states using the applied field. It is also shown that the ensemble of channels which mutually interact in a cooperative manner via the bulk solution under the sufficiently strong dependence of the rate constants upon the conformational variable may possess various types of dynamic behavior such as monostability, bistability, and relaxation oscillations.