Constant pressure and temperature molecular dynamics simulation of a fully hydrated liquid crystal phase dipalmitoylphosphatidylcholine bilayer.
Constant pressure and temperature molecular dynamics simulation of a fully hydrated liquid crystal phase dipalmitoylphosphatidylcholine bilayer.
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全水合液晶相二棕榈酰磷脂酰胆碱双层的恒压和恒温分子动力学模拟。
DOI：
10.1016/s0006-3495(95)80126-8
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Klein,ML
中科院分区：
文献类型：
--
作者：
Tu,K;Tobias,DJ;Klein,ML
我们报告了一个恒定的压力和温度的分子动力学模拟的完全水合的液晶（L α）相双层的二棕榈酰磷脂酰胆碱在50摄氏度和28水分子/脂质。我们已经表明，在整个1550 ps的模拟双层是稳定的，并已证明收敛的系统尺寸。双层结构的几个重要方面进行了研究，并与实验结果进行了比较。例如，特定碳原子沿着双层法线的平均位置与中子衍射数据吻合良好，电子密度分布与X射线衍射结果雅阁。烃链氘有序参数与链中部的核磁共振结果相当一致，但模拟预测链末端的有序度过高。尽管在顺序参数的偏差，烃链堆积密度似乎基本上是正确的，因为面积/脂质和双层厚度与最精确的实验估计是一致的。甘油和胆碱基团的氘序参数，以及磷化学位移各向异性，与从NMR测量中提取的定性一致。
We report a constant pressure and temperature molecular dynamics simulation of a fully hydrated liquid crystal (L alpha) phase bilayer of dipalmitoylphosphatidylcholine at 50 degrees C and 28 water molecules/lipid. We have shown that the bilayer is stable throughout the 1550-ps simulation and have demonstrated convergence of the system dimensions. Several important aspects of the bilayer structure have been investigated and compared favorably with experimental results. For example, the average positions of specific carbon atoms along the bilayer normal agree well with neutron diffraction data, and the electron density profile is in accord with x-ray diffraction results. The hydrocarbon chain deuterium order parameters agree reasonably well with NMR results for the middles of the chains, but the simulation predicts too much order at the chain ends. In spite of the deviations in the order parameters, the hydrocarbon chain packing density appears to be essentially correct, inasmuch as the area/lipid and bilayer thickness are in agreement with the most refined experimental estimates. The deuterium order parameters for the glycerol and choline groups, as well as the phosphorus chemical shift anisotropy, are in qualitative agreement with those extracted from NMR measurements.