Molecular Dynamics Analysis of High Electric Pulse Effects on Bilayer Membranes Containing DPPC and DPPS

A molecular dynamics simulator is used to analyze the electrically driven membrane effects in cells due to ultrashort pulses. Time dependence of nanopore formation at membranes in response to a high-intensity (~ 100 kV/cm), nanosecond electric pulse is probed. The results show that the nanosized pores could typically be formed in ~ 5-6 ns. Phosphatidylserine externalization is shown to occur as a pore-mediated event, rather than a translocation across an energy barrier. The predictions are in a very good agreement with the recent experimental data, including the preference for "anode-side" initiation. Finally, it is shown that the molecular system could potentially evolve from an initial multiple nanopore state to a system dominated by larger sized pores