We have located links that may give you full text access.
Molecular Dynamics Investigation of the Ternary Bilayer Formed by Saturated Phosphotidylcholine, Sphingomyelin, and Cholesterol.
Journal of Physical Chemistry. B 2018 December 14
Using the all-atom CHARMM36 force field, we have performed molecular dynamics simulations of the equimolar ternary dimyristoylphosphatidylcholine (DMPC)/ N-palmitoylsphingomyelin (PSM)/cholesterol bilayer. Analysis of its structural and kinetic properties has led us to the following conclusions. First, the DMPC/PSM/cholesterol bilayer features favorable interactions of cholesterol with DMPC and, particularly, PSM lipids, which are supported by hydrogen bonds. In contrast, the interactions between cholesterol molecules are strongly suppressed. Further analysis shows that about 60% of PSM molecules form hydrogen bonds with other PSM or cholesterol molecules and, to a lesser degree, with DMPC lipids. Second, local lipid packing around PSM molecules favors parallel or antiparallel alignments, resulting in the appearance of large anisotropic chain-like clusters formed by PSM lipids. In contrast, the distribution of DMPC lipids is closer to ideal, whereas the cholesterol distribution is sharply shifted toward small clusters or isolated molecules. Third, intermolecular interactions and mismatch in fatty acid tail lengths significantly slow down PSM rotational relaxation compared to that for DMPC, and PSM, but not DMPC lipids, tend to combine axial rotation with wobbling. Fourth, the analysis of cholesterol hydration indicates that lipid headgroups at most block about 30% of water molecules from reaching cholesterol, hinting at limited applicability of the umbrella model. Finally, we show that PSM and DMPC lipids predominantly exist in two equally probable conformational states, with and without a kink in their fatty acid tails. The appearance of these states is linked to the impact of cholesterol. Comparisons with previous studies allow us to delineate contributions of cholesterol, PSM, and DMPC to bilayer properties.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app