Effects of phospholipid unsaturation on the bilayer nonpolar region

Tomasz Róg, Krzysztof Murzyn, Ryszard Gurbiel, Yuji Takaoka, Akihiro Kusumi, Marta Pasenkiewicz-Gierula
2003 Journal of Lipid Research  
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 ␤ -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,
more » ... s 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 ␤ 10 and ␤ 12 of the single bonds next to the double bond in the oleoyl (O) and elaidoyl (E) chains. Broader distributions of ␤ 10 and ␤ 12 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 ( ␤ 4 and ␤ 5) is similar to that of cholesterol on these torsions in a myristoyl chain. -Róg, T., K. Murzyn, R. Gurbiel, Y. Takaoka, A. Kusumi, and M. Pasenkiewicz-Gierula. Effects of phospholipid unsaturation on the bilayer nonpolar region: a molecular simulation study.
doi:10.1194/jlr.m300187-jlr200 pmid:14594994 fatcat:o3jews4ygjef7g3ab6vcv4yav4