Molecular Dynamics Simulations of Mixed Acidic/Zwitterionic Phospholipid Bilayers
Molecular Dynamics Simulations of Mixed Acidic/Zwitterionic Phospholipid Bilayers
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DOI：
10.1016/j.bpj.2010.04.064
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发表时间：
2010-08-04
影响因子：
3.4
通讯作者：
Reuter, Nathalie
中科院分区：
文献类型：
--
作者：
Broemstrup, Torben;Reuter, Nathalie
阴离子脂质是细胞膜的关键成分。许多细胞调节和信号传导机制依赖于它们与膜结合蛋白之间复杂的相互作用。磷脂双层通常用作实验或理论研究中的模型系统，以深入了解生物膜的结构和动力学。我们在这里报告200 ns长的纯（DMPC和DMPG）和混合等摩尔（DMPC/DMPG，DMPC/DMPS和DMPC/DMPA）双层，每个包含256个脂质的MD模拟。分析和比较了纯双层膜和混合双层膜中分子内和分子间的相互作用模式。研究了一价离子（Na+）对盐桥形成的影响。特别地，在DMPS存在下Na+介导的簇的数目高于DMPG和DMPA。我们观察到的DMPS（和在一定程度上DMPA）脂质在一起，而不是与DMPC分子，这可以解释实验观察到的相分离DMPC/DMPS和DMPC/DMPA双层的优先集群。
Anionic lipids are key components in the cell membranes. Many cell-regulatory and signaling mechanisms depend upon a complicated interplay between them and membrane-bound proteins. Phospholipid bilayers are commonly used as model systems in experimental or theoretical studies to gain insight into the structure and dynamics of biological membranes. We report here 200-ns-long MD simulations of pure (DMPC and DMPG) and mixed equimolar (DMPC/DMPG, DMPC/DMPS, and DMPC/DMPA) bilayers that each contain 256 lipids. The intra- and intermolecular interaction patterns in pure and mixed bilayers are analyzed and compared. The effect of monovalent ions (Na+) on the formation of salt-bridges is investigated. In particular, the number of Na+-mediated clusters in the presence of DMPS is higher than with DMPG and DMPA. We observe a preferential clustering of DMPS (and to some extent DMPA) lipids together rather than with DMPC molecules, which can explain the phase separation observed experimentally for DMPC/DMPS and DMPC/DMPA bilayers.