Molecular Dynamics Simulations of Ceramide and Ceramide-Phosphatidylcholine Bilayers

• DOI: 10.1021/acs.jpcb.7b08967
• Publication Date: 2017-10-11T02:29:15Z
• Authors: Eric Wang; Jeffery B. Klauda
• Keywords: POPC; Lipid bilayer mechanics

Recent studies in lipid raft formation and stratum corneum permeability have focused on the role of ceramides (CER). In this study, we use all-atom CHARMM36 (C36) force field to simulate bilayers using N-palmitoylsphingosine (CER16) or α-hydroxy-N-stearoyl phytosphingosine (CER[AP]) 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), which serve as general membrane models. Conditions are replicated from experimental for comparison purposes, concentration (XCER) is varied probe effect CER these systems. Comparisons with experiment based deuterium order parameters bilayer thickness demonstrate good agreement, thus supporting further C36 field. shown a profound nearly all properties including surface area per lipid, chain tilt, compressibility moduli, thickness, hydrogen bonding, clustering. Hydrogen bonding particular can significantly affect other even encourage transition gel phase. Despite CER's tendency condense membrane, an expansion lipids increasing XCER possible depending how balance between various hydrogen-bond pairs clustering perturbed. Based phase transitions, support given phytosphingosine's bridge sphingosine ordered domains corneum.