CHRONOPOTENTIOMETRIC STUDIES OF ELECTROPORATION OF BILAYER-LIPID MEMBRANES

The constant-intensity current chronopotentiometric measurements of eg g yolk phosphatidylcholine bilayer membranes (BLM) are presented. It i s demonstrated that a constant-intensity current flowing through the b ilayer membranes generates the pores in their structures, For the curr ent intensify from 0.1 to 2.0 nA, the generated pores open and close c yclically. The frequency of oscillations depends on the current intens ity: the higher current intensity the higher frequency of pore oscilla tions, It is suggested that the presented method may allow to create o ne pore in BLM and to observe its dynamical behaviour. Based on chrono potentiometric curves, a method of pore conductance calculations is pr esented. It is demonstrated that the value of obtained conductance can be applied for pore diameter estimation, The hypothetical application of constant-current method as a biotechnological tool for selective a nd controlled incorporation of molecules into microorganisms is discus sed. (C) 1998 Elsevier Science B.V.