Coupling nonpolar and polar solvation free energies in implicit solvent models
Coupling nonpolar and polar solvation free energies in implicit solvent models
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DOI：
10.1063/1.2171192
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发表时间：
2006-02-28
影响因子：
4.4
通讯作者：
McCammon, JA
中科院分区：
文献类型：
--
作者：
Dzubiella, J;Swanson, JMJ;McCammon, JA
最近对原子和纳米溶质溶剂化的研究表明，疏水、分散和静电对溶剂化自由能的贡献之间存在着强烈的耦合，这一方面在目前的隐式溶剂模型中是没有考虑的。我们提出了一个理论公式，它通过最小化溶剂相对于溶剂体积排除函数的吉布斯自由能来解释耦合。所得的微分方程式类似于拉普拉斯-杨方程，用于毛细管界面的几何描述，但通过显式考虑曲率修正以及色散和静电贡献，将其扩展到微观尺度。与现有的隐式溶剂方法不同，溶剂可及表面是我们模型的输出。给出了不同长度尺度的中性或带电溶质的球对称或柱对称体系的算例。结果与计算机模拟一致，最重要的是，我们的方法捕捉到了溶剂排出和去湿对特定形式的溶剂-溶质相互作用的强烈敏感性。
Recent studies on the solvation of atomistic and nanoscale solutes indicate that a strong coupling exists between the hydrophobic, dispersion, and electrostatic contributions to the solvation free energy, a facet not considered in current implicit solvent models. We suggest a theoretical formalism which accounts for coupling by minimizing the Gibbs free energy of the solvent with respect to a solvent volume exclusion function. The resulting differential equation is similar to the Laplace-Young equation for the geometrical description of capillary interfaces but is extended to microscopic scales by explicitly considering curvature corrections as well as dispersion and electrostatic contributions. Unlike existing implicit solvent approaches, the solvent accessible surface is an output of our model. The presented formalism is illustrated on spherically or cylindrically symmetrical systems of neutral or charged solutes on different length scales. The results are in agreement with computer simulations and, most importantly, demonstrate that our method captures the strong sensitivity of solvent expulsion and dewetting to the particular form of the solvent-solute interactions.