title: Asymmetric charge distributions in planar bilayer systems.
abstract: Using the simple argument based on irreversible thermodynamics and the Gouy-Chapman theory of the double layer, we show that the equilibrium distribution of charged lipid molecules between the two surfaces of a bilayer is asymmetric if the two solutions bathing the surfaces have the same ionic strength but contain ions of different valencies. For example, if one bathing solution contains 0.10 M NaCl and the other contains 0.70 M NaCl and 0.10 M CaCl2, the ratio of charged lipid molecules of the two surfaces in a membrane that contains 50% total negative lipids is 1.46, leading to a transbilayer potential of 18 mV. A complete set of such numerical results is presented in four figures.
mesh_terms: D001692:Biological Transport; D007700:Kinetics; D008055:Lipids; D008433:Mathematics; D008564:Membrane Potentials; D008567:Membranes, Artificial; D008954:Models, Biological; D009994:Osmolar Concentration; D013816:Thermodynamics
chemical_list: D008055:Lipids; D008567:Membranes, Artificial