Pluhackova Kristyna, Morhenn Humphrey, Lautner Lisa, Lohstroh Wiebke, Nemkovski Kirill S, Unruh Tobias, Böckmann Rainer A
Computational Biology, Department of Biology, University of Erlangen-Nürnberg , Staudtstrasse 5, 91058 Erlangen, Germany.
Lehrstuhl für Kristallografie und Strukturphysik, Department Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg , Staudtstrasse 3, 91058 Erlangen, Germany.
J Phys Chem B. 2015 Dec 10;119(49):15287-99. doi: 10.1021/acs.jpcb.5b08569. Epub 2015 Nov 30.
The recently presented LOPLS-AA all-atom force field for long hydrocarbon chains, based on the OPLS-AA force field, was extended to alcohols, esters, and glyceryl monooleate (GMO) lipids as a model lipid. Dihedral angles were fitted against high level ab initio calculations, and ester charges were increased to improve their hydration properties. Additionally, the ester Lennard-Jones parameters were readjusted to reproduce experimental liquid bulk properties, densities, and heats of vaporization. This extension enabled the setup of LOPLS-AA parameters for GMO molecules. The properties of the lipid force field were tested for the liquid-crystalline phase of a GMO bilayer. The obtained area per lipid for GMO is in good agreement with experiment. Additionally, the lipid dynamics on the subpicosecond to the nanosecond time scale is in excellent agreement with results from time-of-flight (TOF) quasielastic neutron scattering (QENS) experiments on a multilamellar monoolein system, enabling here for the first time the critical evaluation of the short-time dynamics obtained from a molecular dynamics simulation of a membrane system.
最近提出的基于OPLS-AA力场的用于长烃链的LOPLS-AA全原子力场，已扩展到醇类、酯类以及作为模型脂质的甘油单油酸酯（GMO）脂质。二面角通过高水平的从头算计算进行拟合，酯类电荷增加以改善其水合性质。此外，重新调整了酯类的 Lennard-Jones 参数，以再现实验得到的液体体积性质、密度和汽化热。这种扩展使得能够设置GMO分子的LOPLS-AA参数。对GMO双层的液晶相测试了脂质力场的性质。所获得的GMO每脂质分子面积与实验结果吻合良好。此外，从亚皮秒到纳秒时间尺度的脂质动力学与多层单油酸甘油酯系统的飞行时间（TOF）准弹性中子散射（QENS）实验结果高度吻合，首次在此实现了对从膜系统分子动力学模拟获得的短时间动力学的关键评估。
