THE ROLE OF PROTEIN SURFACE-CHARGES IN ION BINDING
THE ROLE OF PROTEIN SURFACE-CHARGES IN ION BINDING
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DOI：
10.1038/335651a0
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发表时间：
1988-10-13
期刊：
影响因子：
64.8
通讯作者：
FORSEN, S
中科院分区：
文献类型：
--
作者：
LINSE, S;BRODIN, P;FORSEN, S
蛋白质工程是一种探测静电相互作用在蛋白质功能中的作用的手段;这种优雅的技术已被应用于阐明酶催化中的静电效应1。在这里，我们展示了如何使用突变蛋白质允许确定的贡献，个别电荷的离子结合蛋白质的自由能。我们已经研究了三个带负电荷的侧链在钙离子与牛钙结合蛋白D9 K结合中的重要性（参考文献2）：这些侧链聚集在钙离子位点周围，但不直接作为配体参与。发现这些电荷中的每一个都对两个Ca ~（2+）离子的结合自由能贡献了1.7kJ·mol ~（-1），并影响Ca ~（2+）结合的协同性。表面电荷对离子与蛋白质结合的影响可能比通常认为的更常见，并且可能对蛋白质功能产生重要影响。
Protein engineering is a means of probing the role of electrostatic interactions in protein functions; this elegant technique has been applied to the elucidation of electrostatic effects in enzyme catalysis1. Here we show how the use of mutant proteins allows the determination of the contributions of individual charges to the free energy of ion binding to proteins. We have investigated the importance of three negatively charged side chains in the binding of Ca2+to bovine calbindin D9K(ref. 2): these are clustered around the calcium sites but are not directly involved as ligands. Each of these charges is found to contribute ˜7 kJ mol–1to the free energy of binding of two Ca2+ions and to affect the cooperativity of Ca2+binding. The influence of surface charges on ion binding to proteins may be more common than generally supposed and could have important consequences for protein function.