A comparison of straight- and branch-chained lipid bilayers for the static and dynamic properties: A molecular dynamics study.
W. Shinoda, M. Mikami, T. Baba, and M. Hato
National Institute of Advanced Industrial Science & Technology, JP
Keywords: molecular dynamics, lipid bilayers, phytanyl chain, branched chain, stability
A bilayer composed of branched chain lipid molecules is generally believed to have high bilayer stability and low ion leakage. To understand how the chain branching affects the bilayer properties on the molecular level, two molecular dynamics simulations of lipid bilayers have been undertaken in the isothermal-isobaric ensemble. The first simulation was carried out on the straight-chained DPPC bilayer, the second on the branch-chained DPhPC. The detailed analyses on the chain conformation revealed that the branched chain had less-ordered local structure. As for the intermolecular packing order in the bilayer plane, however, a relatively neat lipid arrangement was observed for the branch-chained DPhPC bilayer by a Voronoi analysis for the center of mass of the lipid. On the other hand, a significant lowering in the chain mobility was observed as a result of chain branching. The high bilayer stability of the branch-chained DPhPC bilayer would arise from the low chain mobility and the neat lateral arrangement of the lipid in the bilayer.
NSTI Nanotech 2003 Conference Technical Program Abstract