A study of the tautomeric equilibria of 2-hydroxypyridine/2-oxopyridine and of cytosine in water using the coupled reference interaction site model(RISM)/molecular dynamics (MD) approach
A study of the tautomeric equilibria of 2-hydroxypyridine/2-oxopyridine and of cytosine in water using the coupled reference interaction site model(RISM)/molecular dynamics (MD) approach
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DOI：
10.1021/jp046453y
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发表时间：
2004-12-09
影响因子：
3.3
通讯作者：
Truong, TN
中科院分区：
文献类型：
--
作者：
Freedman, H;Nguyen, HN;Truong, TN
我们介绍了最近提出的耦合参考相互作用位点模型（RISM）/分子动力学（MD）溶剂化自由能方法（Freedman，H.; Truong，T. N.化学物理学报2003，381，362; J.Chem.Phys.2004，121，2187）来研究水合作用对2-羟基吡啶和2-氧代吡啶以及胞嘧啶在水中的互变异构平衡的影响。在这种方法中，溶剂化系统的模拟轨迹计算和平均，以确定径向分布函数，然后插入到RISM表达的溶剂化自由能。计算的两种互变异构的水合自由能的差异与实验数据以及以前的自由能模拟的结果吻合得很好。这是特别令人鼓舞的，因为耦合RISM/MD方法需要一个单一的MD模拟相比，更复杂和计算要求的自由能模拟方法。
We present an application of the recently proposed coupled reference interation site model (RISM)/molecular dynamics (MD) solvation free-energy method (Freedman, H.; Truong, T. N. Chem. Phys. Lett. 2003, 381, 362; J. Chem. Phys. 2004, 121, 2187) to study the hydration effect upon the tautomeric equilibria of 2-hydroxypyridine and 2-oxopyridine and of cytosine in water. In this methodology, simulation trajectories of solvated systems are computed and averaged to determine radial distribution functions, which are then inserted into a RISM expression for the solvation free energy. The computed differences in free energy of hydration for the two tautomerizations agree well with the experimental data as well as results from previous free-energy simulations. This is particularly encouraging since the coupled RISM/MD method requires a single MD simulation as compared to the more complicated and computationally demanding free-energy simulation methods.