A theoretical analysis on hydration thermodynamics of proteins
A theoretical analysis on hydration thermodynamics of proteins
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DOI：
10.1063/1.2213980
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发表时间：
2006-07-14
影响因子：
4.4
通讯作者：
Hirata, Fumio
中科院分区：
文献类型：
--
作者：
Imai, Takashi;Harano, Yuichi;Hirata, Fumio
利用三维参考相互作用位点模型理论（一种最近发展的分子溶剂化积分方程理论）计算使用全原子力场建模的几种蛋白质的水合自由能（HFE）。在等容条件下，HFE 分解为能量和熵分量。前者包括蛋白质-水相互作用能和由水引起的结构变化产生的水重组能。每个组件进一步分解为非静电和静电贡献。研究发现，HFE 受非静电水合熵和静电水合能的控制。非静电水合熵几乎完全归因于蛋白质插入时水的平移熵损失。随着蛋白质大小的增加，它逐渐与水分子的排除体积 (EV) 成正比。水合能由蛋白质-水相互作用能决定，该相互作用能由水重组能补偿一半。这些能量项大约与可接触水的表面积（ASA）成正比。能量和熵的贡献相互平衡，并且 HFE 与 EV 和 ASA 没有明显的线性关系。 (c) 2006 年美国物理研究所。
The hydration free energy (HFE) of several proteins modeled using the all-atom force field is calculated by employing the three-dimensional reference interaction site model theory, a recently developed integral equation theory of molecular solvation. The HFE is decomposed into the energetic and entropic components under the isochoric condition. The former comprises the protein-water interaction energy and the water reorganization energy arising from the structural changes induced in water. Each component is further decomposed into the nonelectrostatic and electrostatic contributions. It is found that the HFE is governed by the nonelectrostatic hydration entropy and the electrostatic hydration energy. The nonelectrostatic hydration entropy is almost exclusively ascribed to the translational entropy loss of water upon the protein insertion. It asymptotically becomes proportional to the excluded volume (EV) for water molecules as the protein size increases. The hydration energy is determined by the protein-water interaction energy which is half compensated by the water reorganization energy. These energy terms are approximately proportional to the water-accessible surface area (ASA). The energetic and entropic contributions are balanced with each other and the HFE has no apparent linear relation with the EV and ASA. (c) 2006 American Institute of Physics.