Examination of Mixtures Containing Sphingomyelin and Cholesterol by Molecular Dynamics Simulations

• DOI: 10.1021/acs.jpcb.7b01832
• Publication Date: 2017-04-12T00:21:00Z
• Authors: Eric Wang; Jeffery B. Klauda
• Keywords: Dynamics

The all-atom CHARMM36 (C36) force field is used to simulate bilayers of pure palmitoylsphingomyelin (PSM) as well binary mixtures PSM and stearoylsphingomyelin (SSM) at various cholesterol concentrations (XC) temperatures. C36 simulation data in good agreement with experimental deuterium order parameters previous computational results, providing evidence the utility for potentially studying more complex membranes. area compressibility modulus shown achieve a large value 2.82 ± 0.08 N/m cholesterol-rich membranes (XC = 0.50). Surface per lipid (SA/lip), tilt angle, membrane thicknesses, acyl chain ordering are have strong dependencies on concentration. Relaxation times also indicate dependence show preference rotational axial motion over wobbling motion. Radial distribution functions clustering relationships between lateral hydrogen bonding, which long lived SM These interactions lead self-association high concentrations, causing shielding from further SM-cholesterol interactions. importance ternary component SM-SM bonds revealed light results consequential modeling rafts.