Ionic conductivity of electroporated lipid bilayer membranes.

The ionic conductivity of lipid membrane pores has been theoretically analysed in terms of electrostatic interactions of the transported ions with the low-dielectric pore wall for a commonly encountered case of unequal concentrations of electrolyte on the two sides of curved lipid membranes. Theoretical analysis of the data on the conductivity of the electroporated membrane of lipid vesicles (Lecithin 20%) of radius a=90 nm yields the molar energy of interaction of a small monovalent ion with a pore wall w(0)=9+/-1 RT (or w(0)=22+/-kJ mol(-1)), corresponding to a mean pore radius of (-)r(p)=0.56+/-0.05 nm. The proposed theoretical approach provides a tool for the analysis and description of the nonlinear current-voltage dependencies in membrane pores and channels.