Róg Tomasz, Pasenkiewicz-Gierula Marta
Department of Biophysics, Institute of Molecular Biology and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland.
Biophys J. 2003 Mar;84(3):1818-26. doi: 10.1016/S0006-3495(03)74989-3.
Epicholesterol (Echol) is an epimeric form of cholesterol (Chol). A molecular dynamics simulation of the fully hydrated dimyristoylphosphatidylcholine-Echol (DMPC-Echol) bilayer membrane containing approximately 22 mol % of Echol was carried out for 5 ns. A 3-ns trajectory generated between 2 and 5 ns of molecular dynamics simulation was used for analyses to determine the effects of Echol on the membrane properties. As reference systems, pure DMPC and mixed DMPC-Chol bilayers were used. The study shows that Echol, like Chol, changes the organization of the bilayer/water interface and increases membrane order and condensation, but to a lesser degree. Effects of both sterols are based on the same atomic level mechanisms; their different strength arises from different vertical localizations of Echol and Chol hydroxyl groups in the membrane/water interface.
表胆固醇（Echol）是胆固醇（Chol）的一种差向异构体形式。对含有约22摩尔％Echol的完全水合二肉豆蔻酰磷脂酰胆碱 - Echol（DMPC - Echol）双层膜进行了5纳秒的分子动力学模拟。使用分子动力学模拟2至5纳秒之间生成的3纳秒轨迹进行分析，以确定Echol对膜性质的影响。作为参考系统，使用了纯DMPC和混合DMPC - Chol双层膜。研究表明，Echol与Chol一样，会改变双层/水界面的组织结构，并增加膜的有序性和凝聚性，但程度较小。两种甾醇的作用基于相同的原子水平机制；它们不同的强度源于Echol和Chol羟基在膜/水界面中的不同垂直定位。
