RUI: Molecular Dynamics Simulations of Lipid Bilayer Membranes

9728206费勒原子级计算机模拟将用于探索包含各种磷脂以及小溶质、非离子表面活性剂和多肽的双层膜的结构和动力学。由于生理温度下脂类存在的液晶相的固有无序性，原子级结构数据很难通过实验获得。因此，这些模拟将补充现有的实验数据。这些实验数据将在这个项目中以两种方式使用。在可能的情况下，将在模拟中观察到的特性与实验获得的特性进行比较，以测试工作的有效性。其次，这些模拟的许多分析都以提取可用于解释实验的双层性质为目标。这项研究的具体目标是测定脂分子碎片的体积，其精度在实验上是无法获得的。这些数据将用于将填充模型引入到膜衍射实验的解释中。将确定与每个碎片相关联的自由或空隙体积的比例。这将解决脂质的特定部分在小溶质渗透膜中所起的作用。由于双层膜对细胞结构和功能的重要性，该项目具有生物学意义。这项工作将提供原子水平的双层体系的详细图景，并将提供关于脂质特定部分在渗透中的作用的信息。***

9728206 Feller Atomic-level computer simulations will be used to probe the structure and dynamics of bilayer membranes containing a variety of phospholipids, as well as small solutes, nonionic surfactants, and peptides. Because of the inherent disorder in the liquid-crystalline phase in which lipids exist at physiological temperature, atomic level structural data are extremely difficult to obtain experimentally. Thus these simulations will complement the existing body of experimental data. These experimental data will be used in two ways for this project. Where possible, comparison will be made between properties observed in the simulation with those obtained experimentally in order to test the validity of the work. Secondly, many of the analyses of these simulations have as their goal the extraction of bilayer properties which can be utilized in the interpretation of experiments. The specific objectives of this research are the determinations of the volumes of fragments of lipid molecules with a precision not available experimentally. These data will be used to introduce packing models into the interpretation of membrane diffraction experiments. The fraction of free or void volume associated with each fragment will be determined. This will address the role played by specific parts of the lipid in the permeation of the membrane by small solutes. This project has biological relevance because of the importance of bilayer membranes to cell structure and function. This work will provide a detailed picture of bilayer systems at the atomic level, and will provide information on the roles of specific parts of the lipid in permeation. ***