The H+/OH- flux localizes around the channel mouth in buffered solution

The effects of buffering agents present in the solution on the fluxes of H+/OH- through a single channel were theoretically examined under physiological biochemical conditions, i.e. where the concentration of the buffer is in the millimolar range and the pH is around neutral. The solution of the diffusion equation for particles of finite lifetime showed that the convergence permeability can be defined as well as in the case of infinite lifetime, i.e. under non-buffered conditions. The presence of buffers resulted in localization of the H+/OH- fluxes around the channel mouth and enhanced leveling of the ionic concentrations. These results present the basis for arguments on vesicle kinetics and on local chemiosmotic models.