Membrane Electroconformational Changes: Progress in Theoretical Modelling of Electroporation and of Protein Protrusion Alteration

摘要: Unambiguous, non-thermal effects of electric fields on biological cells have been reported by many investigators for moderate and strong (10 to 10 4 volt/cm; shorter exposure times larger fields). This includes electroporation, which is believed due transient long lived pores in cell membranes. In order develop theoretical models such phenomena, we note that electrical interactions with are generally expected because the heterogeneity respect two basic parameters, conductivity permittivity. particularly striking membrane/aqueous electrolyte interfaces, leads general possibility membrane forces. Possible responses forces include overall deformation, indentations perforations (pores). Differential proteins also possible, altering protein protrusion from membrane. To alter living cells, changes must biochemical processes, e.g. transmembrane chemical fluxes. Here describe progress developing a quantitative theory electroporation new possibility: proteins. case emphasize predictions measurable quantities, viz. voltage, U(t), molecular transport, Ns, total number molecules given size charge cross particular pulse. Modelling both artificial planar bilayer membranes possible. The much simpler, therefore focus initial theories. macromolecule protrusion, could lead alteration binding site accessibility, thereby provide “signaling” possibility. Finally, using “signal-to-(background + noise) ratio” (S/B+N) criteria, thresholds field can be estimated. Electroporation has large (S/B+N), while other electroconformational change phenomena may involve smaller values. By approximate criterion (S/B N) ≈ 1, smallest an effect