Electrophoretic measurements about the relation between transition voltage and zeta-potential of biological membranes

The effects of inorganic cations, n-hexanol, saccharose and 2H2O on the electrophoretic mobility and zeta-potential of membrane vesicles from nerve myelin were measured and the results compared with the corresponding effects of the same reagents on the transition voltage, VTr, of the nerve axon membrane. Different cation concentrations and 2H2O affect both potentials, the zeta-potential and VTr, in a parallel way. Saccharose and n-hexanol, however, shift VTr but leave the electrophoretic mobility of the myelin vesicles unchanged. These results suggest that VTr shifts are not necessarily linked to changes in the membrane surface charge density but may also be caused by an interaction between the reagent and non-polar groups of the membrane interior.