Hydroxyl ion permeability of lipid bilayer membranes.
The OH- permeability of lipid bilayer (egg phosphatidylcholine-cholesterol) membranes was estimated from ionic transference numbers and membrane conductances at high pH. Membranes are slightly cation (Na+) selective over the pH range of 6--10. However, at pH greater than 11, Na+ and Cl- conductances decrease and OH- conductance increases so that the membrane becomes highly selective to OH-. From the OH- conductance we estimate the OH- permeability coefficient to be 1.8 . 10(-9) cm . s-1. The OH- selectivity of lipid bilayers may contribute to the observed H+/OH- selectivity of some biological membrane at high pH.
D002712:Chlorides / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000378:metabolism*; D008051:Lipid Bilayers / Q000378:metabolism*; D008564:Membrane Potentials; D010713:Phosphatidylcholines / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002712:Chlorides; D006878:Hydroxides; D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D002784:Cholesterol; D012964:Sodium