[Transmembrane redox reactions, coupled with proton transfer in lipid bilayer membranes].

The transmembrane reaction of ferricyanide reduction by exogenous ascorbate in the liposomes in the presence of N,N,N',N'-tetramethylparaphenylenediamine (TMPD) or 2,3,5,6-tetramethylphenylenediamine (DAD) was investigated. The reaction equilibrium was shown to depend on the intraliposomal pH. At alkaline pH values under the experimental conditions used TMPD functions mainly as an electron carrier, while at acidic pH values TMPD effectuates a coupled transmembrane electron and proton transfer. This reaction is paralleled with local changes in the pH values in the unstirred layer near the membrane.