Computer simulations of lipid bilayer dynamics

The dynamical properties of membranes, i.e., lipid bilayers, in aqueous solvent have been investigated by means of coarse-grained molecular dynamics simulations. Because of their amphiphilic nature, lipids dissolved in water can form a wide range of clusters, from spherical globules and worm-like micelles to bilayers and vesicles, where the hydrophobic tails of the lipids are shielded from the surrounding solvent by their hydrophilic heads. The particular lipids simulated here self-assemble into a bilayer-structure, which is mirror symmetric with respect to its mid-plane. Because bilayers are held together by relative weak non-bonded interaction forces, they behave in many respects as two-dimensional liquids suspended in a three-dimensional solvent matrix. This makes bilayers very susceptible to external forces, which give rise to deformations of the overall shape of the bilayer and to ow within the bilayer.