We studied effects of lipid chain branching on structural and dynamical properties of the lipid bilayers by a comparative molecular dynamics simulation of dipalmitoyl phosphatidylcholine (DPPC) and diphytanoyl phosphatidylcholine (DPhPC) bilayers. Trans-gauche isomerization rate at the dihedrals along the hydrophobic main chain was significantly reduced by chain branching. The slower conformational motion of branched chains lead to slower wobbling of the chain and slower rotational and translational motions of the lipid molecules, compared with straight-chained counterpart. In contrast, headgroup motion was slightly enhanced by the chain branching. The slower dynamics of the branched hydrophobic chains accounts for the high structural bilayer stability and low solute permeability of the branched DPhPC bilayer.
展开▼
