472571 The Influence of Lipid Tail Length and Cholesterol Content on the Structure of Model Stratum Corneum Bilayers
Here, we investigate the structural dependence of SC model lipid bilayers on CER tail length and CHOL content using a modified version of simulated tempering . Simulated tempering, whereby a simulation undergoes a random walk through temperature space, provides a means for systems to escape energetic traps and explore phase space, allowing the system to efficiently decorrelate from the initial, assumed configuration. To investigate the role of the CER tail length on bilayer structure, a series of systems are studied in which the relative amount of short and long-chain CER is varied. Similarly, systems with varying amounts of CHOL are studied to probe the role of CHOL content on bilayer structure. We find that several key structural properties are dependent on both CER tail length and CHOL content, including a strong dependence of tilt angle and interdigitation behavior on the relative lipid concentration, both of which may have significant implications for the barrier function. These results provide new insights into the connections between lipid composition, structure, and barrier properties of the SC.
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