出版社：American Society for Biochemistry and Molecular Biology
摘要：Molecular dynamics simulations of two monounsaturated phosphatidylcholine (PC) bilayers made of 1-palmitoyl-2-oleoyl-PC (POPC; cis -unsaturated) and 1-palmitoyl-2-elaidoyl-PC (PEPC; trans -unsaturated) were carried out to investigate the effect of a double bond in the PC β-chain and its conformation on the bilayer core. Four nanosecond trajectories were used for analyses. A fully saturated 1,2-dimyristoyl-PC (DMPC) bilayer was used as a reference system. In agreement with experimental data, this study shows that properties of the PEPC bilayer are more similar to those of the DMPC than to the POPC bilayer. The differences between POPC and PEPC bilayers may be attributed to the different ranges of angles covered by the torsion angles β10 and β12 of the single bonds next to the double bond in the oleoyl (O) and elaidoyl (E) chains. Broader distributions of β10 and β12 in the E chain than in the O chain make the E chain more flexible. In effect, the packing of chains in the PEPC bilayer is similar to that in the DMPC bilayer, whereas that in the POPC bilayer is looser than that in the DMPC bilayer. The effect of the cis -double bond on torsions at the beginning of the O chain (β4 and β5) is similar to that of cholesterol on these torsions in a myristoyl chain.
