Role of Electrostatics in Modulating Hydrophobic Interactions and Barriers to Hydrophobic Assembly
Role of Electrostatics in Modulating Hydrophobic Interactions and Barriers to Hydrophobic Assembly
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DOI：
10.1021/jp101995d
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发表时间：
2010-06-24
影响因子：
3.3
通讯作者：
Patel, Sandeep
中科院分区：
文献类型：
--
作者：
Bauer, Brad A.;Patel, Sandeep
由于疏水效应对广泛的物理化学现象的影响，疏水效应仍然是一个活跃的研究领域。分子动力学模拟已被广泛用于使用各种水势模型的这种影响的研究，很少有研究解决模型之间的差异。特别是，考虑明确的水的极化率的治疗研究在文献中代表不足。我们目前的分子动力学模拟的结果，系统地比较大规模的疏水效应的依赖水模型。我们考虑三种常见的不可极化模型（SPC/E，TIP 3 P和TIP 4P）和两种常见的极化模型（TIP 4P-FQ和SWM 4-NDP）。结果突出了两个大的疏水板附近的不同的水模型的相似性和差异。特别是，平均密度，密度波动，取向和氢键的配置文件显示只有微小的差异之间的水模型研究。然而，在可极化的水系统中，疏水物二聚化的平均力的潜力显着降低。与TIP 4P、TEMP、SPC/E和SWM 4-NDP的-40（+/-3）、-40（+/-2）、-42（+/-3）和-45（+/-5）kcal/mol相比，TIP 4P-FQ显示出约-54（+/-3）kcal/mol的最深最小值（均相对于解离状态）。我们讨论了疏水缔合和水-水在液相中的相互作用的强度之间的关系。结果表明，模型处理极化（隐式和显式）影响更强的驱动力向疏水组装。这些结果的影响，以及对未来工作的前景进行了讨论。
Hydrophobic effects continue to be an active area of research due to implications for a wide range of physicochemical phenomena. Molecular dynamics simulations have been used extensively in the study of such effects using various water potential models, with few studies addressing the differences between models. In particular, studies considering the explicit treatment of water polarizability are underrepresented in the literature. We present results from molecular dynamics simulations that systematically compare the dependence of large-scale hydrophobic effects on the water model. We consider three common nonpolarizable models (SPC/E, TIP3P, and TIP4P) and two common polarizable models (TIP4P-FQ and SWM4-NDP). Results highlight the similarities and differences of the different water models in the vicinity of two large hydrophobic plates. In particular, profiles of average density, density fluctuations, orientation, and hydrogen bonding show only minor differences among the water models studied. However, the potential of mean force for the hydrophobe dimerization is significantly reduced in the polarizable water systems. TIP4P-FQ shows the deepest minimum of approximately -54(+/-3) kcal/mol compared to -40(+/-3), -40(+/-2), -42(+/-3), and -45(+/-5) kcal/mol for TIP4P, TEMP, SPC/E, and SWM4-NDP (all relative to the dissociated state). We discuss the relationship between hydrophobic association and the strength of water-water interactions in the liquid phase. Results suggest that models treating polarizability (both implicitly and explicitly) influence a stronger driving force toward hydrophobic assembly. Implications of these results, as well as prospectives on future work, are discussed.