Frewein Moritz P K, Rumetshofer Michael, Pabst Georg
University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, 8010 Graz, Austria.
BioTechMed Graz, 8010 Graz, Austria.
J Appl Crystallogr. 2019 Mar 28;52(Pt 2):403-414. doi: 10.1107/S1600576719002760. eCollection 2019 Apr 1.
A global analysis model has been developed for randomly oriented, fully hydrated, inverted hexagonal (H) phases formed by many amphiphiles in aqueous solution, including membrane lipids. The model is based on a structure factor for hexagonally packed rods and a compositional model for the scattering length density, enabling also the analysis of positionally weakly correlated H phases. Bayesian probability theory was used for optimization of the adjustable parameters, which allows parameter correlations to be retrieved in much more detail than standard analysis techniques and thereby enables a realistic error analysis. The model was applied to different phosphatidylethanolamines, including previously unreported H data for diC14:0 and diC16:1 phosphatid-yl-ethanolamine. The extracted structural features include intrinsic lipid curvature, hydrocarbon chain length and area per lipid at the position of the neutral plane.
已开发出一种全局分析模型，用于分析许多两亲分子（包括膜脂）在水溶液中形成的随机取向、完全水合的反相六角（H）相。该模型基于六方堆积棒状结构因子和散射长度密度组成模型，还能分析位置相关性较弱的H相。采用贝叶斯概率理论对可调参数进行优化，与标准分析技术相比，它能更详细地获取参数相关性，从而实现实际的误差分析。该模型应用于不同的磷脂酰乙醇胺，包括二C14:0和二C16:1磷脂酰乙醇胺此前未报道的H数据。提取的结构特征包括固有脂质曲率、烃链长度和中性面位置处每个脂质的面积。
