Dynamic coupling with water contributes to regulating the functional dynamics of a biomolecule. We discuss protein–water dynamics, with emphasis on water that is partially confined, and the role of protein-confined water dynamics in allosteric regulation. These properties are illustrated with two systems, a homodimeric hemoglobin from Scapharca inaequivalvis (HbI) and an A_2A adenosine receptor (A_2AAR). For HbI, water–protein interactions, long known to contribute to the thermodynamics of cooperativity, are seen to influence the dynamics of the protein not only around the protein–water interface but also into the core of each globule, where dynamic and entropic changes upon ligand binding are coupled to protein–water contact dynamics. Similarly, hydration waters trapped deep inside the core region of A_2AAR enable the formation of an allosteric network made of water-mediated inter-residue contacts. Extending from the ligand binding pocket to the G-protein binding site, this allosteric network plays key roles in regulating the activity of the receptor.

中文翻译：

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水介导的生物分子动力学和变构。

与水的动态耦合有助于调节生物分子的功能动力学。我们讨论蛋白质-水动力学，重点是部分受限的水，以及蛋白质受限的水动力学在变构调节中的作用。用两个系统说明了这些性质，一个是来自不等Scapharca inaequivalvis（HbI）的同型二聚体血红蛋白，另一个是A _2A腺苷受体（A _2AAR）。对于HbI，人们长期以来一直认为其与水热相互作用有助于协同作用的热力学，人们认为水与蛋白质之间的相互作用不仅会影响蛋白质-水界面周围的蛋白质动力学，而且还会影响每个小球的核心，在此之后，蛋白质的动态和熵都会发生变化。配体结合与蛋白质-水的接触动力学有关。类似地，困在A _2A AR核心区域内部深处的水化水能够形成由水介导的残基间接触构成的变构网络。该变构网络从配体结合袋延伸到G蛋白结合位点，在调节受体活性中起关键作用。