Influence of external chloride concentration on the kinetics of mobile charges in the cell membrane of Valonia utricularis: Evidence for the existence of a chloride carrier

摘要: Charge pulse relaxation studies were performed on cells of the giant marine alga Valonia utricularis. Two exponential voltage relaxations recorded as found previously (Benz, R., and U. Zimmermann. 1983. Biophys. J. 43:13–26.). The parameters two decays studied a function chloride concentration in artificial sea water. Replacement external by 2( N -morpholino)ethanesulfonate (Mes - ) had dramatic influence four parameters. This dependence could not be satisfactorily explained simplified model used earlier. Accordingly, additional reaction steps to included model. Only processes resolved under all experimental conditions. means that heterogeneous complexation reactions, k R (association), D (dissociation) too fast resolved. Therefore carrier with equilibrium surface reactions was fit results. From charge data at different concentrations translocation rate constants free complexed carriers, S AS , through membrane, well total systems, 0 evaluated. results described here indicate cell membrane utricularis contains an electrogenic transport system for chloride.