Evaluation and reparametrization of the OPLS-AA force field for proteins via comparison with accurate quantum chemical calculations on peptides
Evaluation and reparametrization of the OPLS-AA force field for proteins via comparison with accurate quantum chemical calculations on peptides
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DOI：
10.1021/jp003919d
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发表时间：
2001-07-19
影响因子：
3.3
通讯作者：
Jorgensen, WL
中科院分区：
文献类型：
--
作者：
Kaminski, GA;Friesner, RA;Jorgensen, WL
我们提出了通过重新拟合关键傅立叶扭转系数来改善肽的 OPLS-AA 力场的结果。该拟合技术结合了使用准确的从头开始数据作为目标、选择整个势能表面的有效拟合子空间以及基于势能梯度的大小确定每个拟合点的权重。与 LMP2/cc-pVTZ(-f)//HF/6-31G** 数据的平均能量 RMS 偏差减少了约 10%。由于不带静电的二肽的拟合结果，从 0.81 到 0.47 kcal/mol 40%，通过对所有其他二肽（具有适当的侧链重新拟合）和丙氨酸四肽使用相同的丙氨酸二肽拟合主链扭转参数来证明参数的可转移性。含硫二肽（半胱氨酸和蛋氨酸）的非键相互作用参数也进行了修改，并且通过重现纯模型液体的复杂地层汽化热和密度的气相能量，证明了新库仑电荷以及范德华西格玛和ε的有效性。此外，还提出了一种拟合带静电分子系统扭转参数的新方法，并在五种带有带电侧链的二肽上成功进行了测试。
We present results of improving the OPLS-AA force field for peptides by means of refitting the key Fourier torsional coefficients. The fitting technique combines using accurate ab initio data as the target, choosing an efficient fitting subspace of the whole potential-energy surface, and determining weights for each of the fitting points based on magnitudes of the potential-energy gradient. The average energy RMS deviation from the LMP2/cc-pVTZ(-f)//HF/6-31G** data is reduced by ca. 40% from 0.81 to 0.47 kcal/mol as a result of the fitting for the electrostatically uncharged dipeptides, Transferability of the parameters is demonstrated by using the same alanine dipeptide-fitted backbone torsional parameters for all of the other dipeptides (with the appropriate side-chain refitting) and the alanine tetrapeptide. Parameters of nonbonded interactions have also been refitted for the sulfur-containing dipeptides (cysteine and methionine), and the validity of the new Coulombic charges and the van der Waals sigma 's and epsilon 's is proved through reproducing gas-phase energies of complex formation heats of vaporization and densities of pure model liquids. Moreover, a novel approach to fitting torsional parameters for electrostatically charged molecular systems has been presented and successfully tested on five dipeptides with charged side chains.