Hassanali Ali, Egan Colin K
The "Abdus Salam" International Centre for Theoretical Physics, I-34151 Trieste, Italy.
Entropy (Basel). 2024 Sep 1;26(9):749. doi: 10.3390/e26090749.
The solvent-induced interactions (SIIs) between flexible solutes can be separated into two distinct components: the solvation-induced conformational effect and the joint solvation interaction (JSI). The JSI quantifies the thermodynamic effect of the solvent simultaneously accommodating the solutes, generalizing the typical notion of the hydrophobic interaction. We present a formal definition of the JSI within the framework of the mixture expansion, demonstrate that this definition is equivalent to the SII between rigid solutes, and propose a method, partially connected molecular dynamics, which allows one to compute the interaction with existing free energy algorithms. We also compare the JSI to the more natural generalization of the hydrophobic interaction, the indirect solvent-mediated interaction, and argue that JSI is a more useful quantity for studying solute binding thermodynamics. Direct calculation of the JSI may prove useful in developing our understanding of solvent effects in self-assembly, protein aggregation, and protein folding, for which the isolation of the JSI from the conformational component of the SII becomes important due to the intra-species flexibility.
柔性溶质之间的溶剂诱导相互作用（SIIs）可分为两个不同的组分：溶剂化诱导的构象效应和联合溶剂化相互作用（JSI）。JSI量化了溶剂同时容纳溶质的热力学效应，推广了疏水相互作用的典型概念。我们在混合物展开的框架内给出了JSI的形式定义，证明了该定义等同于刚性溶质之间的SII，并提出了一种方法——部分连接分子动力学，它允许人们使用现有的自由能算法来计算相互作用。我们还将JSI与疏水相互作用更自然的推广——间接溶剂介导相互作用进行了比较，并认为JSI对于研究溶质结合热力学是一个更有用的量。JSI的直接计算可能有助于加深我们对自组装、蛋白质聚集和蛋白质折叠中溶剂效应的理解，对于这些过程，由于物种内部的柔性，将JSI与SII的构象组分分离变得很重要。
