[The effect of the composition of phospholipid bilayer membranes on the steady state kinetic transfer of protons].

When the hydrogen ion flux was induced by nigericin across the planar bilayer lipid membrane (BLM) with the bulk pHs being equal at the opposite sides of the BLM, the formation of the boundary potential difference (delta phi b) on the BLM was observed using the method of the inner membrane field compensation. The increase in the buffer (citrate, phosphate, MES) concentration caused a decrease in the delta phi b. The latter is generated in the presence of phosphatidylserine in membrane-forming solutions only. It was assumed that the steady state difference of the surface hydrogen ion concentration is created under conditions of equal pHs near the BLM surface. In another experimental series the monensin-mediated formation of the surface protein concentration difference gave rise to the formation of a potassium ion gradient induced by nigericin. Thus, a possibility of performing work due to the surface proton concentration gradient was demonstrated. The relevance of these findings to the processes of energy transduction during membrane phosphorylation in mitochondria and chloroplasts is discussed.