Interfacial water structure controls protein conformation
Interfacial water structure controls protein conformation
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DOI：
10.1021/jp066206p
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发表时间：
2007-05-17
影响因子：
3.3
通讯作者：
Ramsden, J. J.
中科院分区：
文献类型：
--
作者：
Der, A.;Kelemen, L.;Ramsden, J. J.
基于蛋白质在盐溶液中的溶解度与蛋白质-水界面张力之间的关系，提出了盐诱导Hofmeister现象的唯象理论。作为以前的治疗的概括，这意味着，这两个kosmotropic盐析和离液盐的表现通过盐诱导的蛋白质-水界面的疏水/亲水特性的变化。该理论适用于描述盐依赖的蛋白质作为其暴露于水的表面积的函数的自由能配置文件。在此基础上，三类蛋白质构象已被区分，并通过实验证明它们的存在，例如细菌视紫红质和肌红蛋白。实验结果支持的能力，新的形式主义，占盐对蛋白质构象，动力学和稳定性的影响的各种表现，并解决了离液剂稳定某些蛋白质（和其他异常）的难题。它还表明，界面张力和蛋白质结构稳定性之间的关系是直接链接到蛋白质的构象波动，Hofmeister效应的微观解释提供了一个基石。关于使用霍夫迈斯特效应的蛋白质功能的实验研究的结果的影响进行了讨论。
A phenomenological theory of salt-induced Hofmeister phenomena is presented, based on a relation between protein solubility in salt solutions and protein-water interfacial tension. As a generalization of previous treatments, it implies that both kosmotropic salting out and chaotropic salting in are manifested via salt-induced changes of the hydrophobic/hydrophilic properties of protein-water interfaces. The theory is applied to describe the salt-dependent free energy profiles of proteins as a function of their water-exposed surface area. On this basis, three classes of protein conformations have been distinguished, and their existence experimentally demonstrated using the examples of bacteriorhodopsin and myoglobin. The experimental results support the ability of the new formalism to account for the diverse manifestations of salt effects on protein conformation, dynamics, and stability, and to resolve the puzzle of chaotropes stabilizing certain proteins (and other anomalies). It is also shown that the relation between interfacial tension and protein structural stability is straightforwardly linked to protein conformational fluctuations, providing a keystone for the microscopic interpretation of Hofmeister effects. Implications of the results concerning the use of Hofmeister effects in the experimental study of protein function are discussed.