Atomistic simulations of the interaction between lipid bilayers and substrates

Abstract

Many modern biological applications involve the interaction of lipid bilayers with a substrate. Although free bilayers in solution have been studied extensively, the influence of a substrate on the complex dynamic behavior of a supported lipid bilayer (SLB) is not fully understood. We present fully atomistic molecular dynamics simulations of a lipid bilayer supported on α-quartz substrates with explicit water molecules. The results show an equilibrium separation distance of 33–35 Å between the lipid and substrate for both bare and hydroxylated quartz substrates, in excellent agreement with experimental measurements. The bilayer adhesion energy is found to be 30 mN/m on a hydroxylated α-quartz surface and 50 mN/m on a bare α-quartz surface, higher than experimental measurements of both free and fixed bilayers.