Institut Charles Sadron Event

Oxidation is a common reaction targeting unsaturated phospholipids composing the membrane of a cell. It changes significantly the molecular composition of a lipid chain and correspondingly impacts the structure and properties of the self-assembled lipid membrane. We study the electro-permeability of model lipid membranes composed of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) containing different fractions of POPC-OOH, the hydroperoxidized form of POPC. By measuring ion currents across a 50 ?m diameter black lipid membrane (BLM) with picoampere and millisecond resolution, we detect hydroperoxidation-induced changes to the intrinsic bilayer electropermeability and to the probability of opening angstrom-size or larger pores. Our results provide not only a clear picture of the effects of oxidation on membrane electropermeability, but challenge also the standard model for how applied electric fields induce pore opening in lipid membranes.