Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, 77845-2128, USA.
Sci Rep. 2020 Oct 16;10(1):17587. doi: 10.1038/s41598-020-74382-5.
Conformational entropy can be an important element of the thermodynamics of protein functions such as the binding of ligands. The observed role for conformational entropy in modulating molecular recognition by proteins is in opposition to an often-invoked theory for the interaction of protein molecules with solvent water. The "solvent slaving" model predicts that protein motion is strongly coupled to various aspects of water such as bulk solvent viscosity and local hydration shell dynamics. Changes in conformational entropy are manifested in alterations of fast internal side chain motion that is detectable by NMR relaxation. We show here that the fast-internal side chain dynamics of several proteins are unaffected by changes to the hydration layer and bulk water. These observations indicate that the participation of conformational entropy in protein function is not dictated by the interaction of protein molecules and solvent water under the range of conditions normally encountered.
构象熵可以是蛋白质功能热力学的一个重要因素，例如配体结合。构象熵在调节蛋白质的分子识别中的作用与经常提到的蛋白质分子与溶剂水相互作用的理论相反。“溶剂奴役”模型预测，蛋白质运动与溶剂水的各个方面（如溶剂的整体粘度和局部水合壳动力学）强烈耦合。构象熵的变化表现为通过 NMR 弛豫可检测到的快速内部侧链运动的改变。我们在这里表明，几个蛋白质的快速内部侧链动力学不受水合层和整体水的变化的影响。这些观察结果表明，在通常遇到的条件范围内，构象熵参与蛋白质功能的程度不受蛋白质分子和溶剂水相互作用的影响。
