title: pH Effect of the sphingomyelin membrane interfacial tension.
abstract: The effect of pH on the interfacial tension of a sphingomyelin membrane in aqueous solution has been studied. Three models describing H(+) and OH(-) ion adsorption on the bilayer lipid surface are presented. In models I and II, the membrane surface is continuous, with uniformly distributed functional groups as centers of H(+) and OH(-) ion adsorption. In model III, the membrane surface is composed of lipid molecules, with and without adsorbed H(+) and OH(-) ions. The contribution of each individual lipid molecule to the overall interfacial tension of the bilayer was assumed to be additive in models I and II. In model III, the Gibbs isotherm was used to describe adsorption of H(+) and OH(-) ions at the bilayer surface. Theoretical equations are derived to describe the interfacial tension as a function of pH for all three models. Maximum interfacial tension was observed experimentally at the isoelectric point.
authors: Institute of Chemistry, University of Bialystok, Bialystok, Poland.
authors: Aneta Dorota
authors: AD
authors: Petelska
authors: Zbigniew Artur
authors: ZA
authors: Figaszewski
mesh_terms: D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008051:Lipid Bilayers / Q000737:chemistry*; D008560:Membrane Fluidity; D008956:Models, Chemical; D013109:Sphingomyelins / Q000737:chemistry*; D013500:Surface Tension
chemical_list: D008051:Lipid Bilayers; D013109:Sphingomyelins