Generation of potential in lipid bilayer membranes as a result of proton-transfer reactions in the unstirred layers.

The addition of an uncoupler in the presence of a concentration gradient of weak acids or bases (sodium acetate and ammonium chloride) leads to the generation of a potential on lipid bilayer membranes (LBM) which is positive in sign on the side of the membrane with a high concentration of sodium acetate and negative on the side with a high concentration of ammonium chloride. It is shown that the potential was caused by the pH gradient in the unstirred layers. These effects can be understood in terms of the previously described [Science, 182, 1258 (1973)] model for the transfer of weak acids and bases through LBM. This system described may be useful for quantitation of permeabilities for weak acids and bases through bilayer membranes.