Electropore Formation in Mechanically Constrained Phospholipid Bilayers

FERNÁNDEZ, M. LAURA; RISK, MARCELO RAÚL; VERNIER, P. THOMAS

JOURNAL OF MEMBRANE BIOLOGY

SPRINGER

Lugar: Berlin; Año: 2017

0022-2631

Molecular dynamics simulations of lipid bilayers in aqueous systems reveal how an applied electric field stabilizes thereorganization of the water?membrane interface into water-filled, membrane-spanning, conductive pores with a symmetric,toroidal geometry. The pore formation process and the resulting symmetric structures are consistent with other mathematicalapproaches such as continuum models formulated to describe the electroporation process. Some experimental data suggest,however, that the shape of lipid electropores in living cell membranes may be asymmetric. We describe here the axially asym-metric pores that form when mechanical constraints are applied to selected phospholipid atoms. Electropore formation pro-ceeds even with severe constraints in place, but pore shape and pore formation time are affected. Since lateral and transversemovement of phospholipids may be restricted in cell membranes by covalent attachments to or non-covalent associationswith other components of the membrane or to membrane-proximate intracellular or extracellular biomolecular assemblies,these lipid-constrained molecular models point the way to more realistic representations of cell membranes in electric fields.