Atomistic simulations of biologically realistic transmembrane potential gradients.
We present all-atom molecular dynamics simulations of biologically realistic transmembrane potential gradients across a DMPC bilayer. These simulations are the first to model this gradient in all-atom detail, with the field generated solely by explicit ion dynamics. Unlike traditional bilayer simulations that have one bilayer per unit cell, we simulate a 170 mV potential gradient by using a unit cell consisting of three salt-water baths separated by two bilayers, with full three-dimensional periodicity. The study shows that current computational resources are powerful enough to generate a truly electrified interface, as we show the predicted effect of the field on the overall charge distribution. Additionally, starting from Poisson's equation, we show a new derivation of the double integral equation for calculating the potential profile in systems with this type of periodicity.
Sachs
Jonathan N
JN
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
Crozier
Paul S
PS
Woolf
Thomas B
TB
D001703:Biophysics / Q000379:methods*; D003198:Computer Simulation; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008564:Membrane Potentials; D008958:Models, Molecular; D015233:Models, Statistical; D008968:Molecular Conformation; D012984:Software; D055672:Static Electricity
D008051:Lipid Bilayers; D004134:Dimyristoylphosphatidylcholine