Effects of two double bonds on the hydrocarbon interior of a phospholipid bilayer

A phospholipid bilayer was modelled by duplicating a monolayer system of 36 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphatidylcholine (PLPC) molecules (16:018:2) plus 1368 water molecules and simulated using molecular dynamics. The analyses revealed distinct characteristics in the membrane structure due to polyunsaturation. The orientational behaviour of the fatty acid chains in the PLPC bilayer was found to be seemingly different from that in monounsaturated or in saturated phospholipid bilayers. The specific attributes responsible for the observed behaviour of the saturated and polyunsaturated chains are discussed and their relative importance assessed.