Effects of epicholesterol on the phosphatidylcholine bilayer: a molecular simulation study.
Epicholesterol (Echol) is an epimeric form of cholesterol (Chol). A molecular dynamics simulation of the fully hydrated dimyristoylphosphatidylcholine-Echol (DMPC-Echol) bilayer membrane containing approximately 22 mol % of Echol was carried out for 5 ns. A 3-ns trajectory generated between 2 and 5 ns of molecular dynamics simulation was used for analyses to determine the effects of Echol on the membrane properties. As reference systems, pure DMPC and mixed DMPC-Chol bilayers were used. The study shows that Echol, like Chol, changes the organization of the bilayer/water interface and increases membrane order and condensation, but to a lesser degree. Effects of both sterols are based on the same atomic level mechanisms; their different strength arises from different vertical localizations of Echol and Chol hydroxyl groups in the membrane/water interface.
Róg
Tomasz
T
Department of Biophysics, Institute of Molecular Biology and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland.
Pasenkiewicz-Gierula
Marta
M
D002784:Cholesterol / Q000737:chemistry*; D003198:Computer Simulation; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008051:Lipid Bilayers / Q000737:chemistry*; D046911:Macromolecular Substances; D008560:Membrane Fluidity; D008958:Models, Molecular; D008968:Molecular Conformation; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
D008051:Lipid Bilayers; D046911:Macromolecular Substances; D014867:Water; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine