A Novel model for saturation of ion conductivity in transmembrane channels

An important experimental finding in measuring ion currents through ion channels like the nicotinic acetylcholine receptor channel is the saturation of the current with increasing ionic strength. Practically all measurements are done at saturating ionic strength. Thus any theory which is supposed to describe the physical behavior of these channels, must predict this saturation, which appears to result from the finite volume of the site to be filled with ions. An Eyring rate theory that takes into account several ions entering the site is presented here. This new model possesses unexpected properties