Conferring thermostability to mesophilic proteins through optimized electrostatic surfaces.
Conferring thermostability to mesophilic proteins through optimized electrostatic surfaces.
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DOI：
10.1016/s0006-3495(03)74707-9
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发表时间：
2003-11
影响因子：
3.4
通讯作者：
M. Torrez;Michael Schultehenrich;D. Livesay
中科院分区：
文献类型：
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作者：
M. Torrez;Michael Schultehenrich;D. Livesay
最近，有一些实验报告表明，通过一两个氨基酸残基的突变，蛋白质显示出明显的稳定性增益。在这里，我们采用一个简单的理论模型来快速筛选突变结构，通过优化蛋白质的静电表面来提高热稳定性。我们的结果能够重现实验观察结果，即消除蛋白质表面上的同电荷排斥和产生相反电荷吸引力是赋予嗜温蛋白质热稳定性的有效方法。利用泊松-玻尔兹曼静电学，我们计算了冷激、RNase T1 和 CheY 蛋白的详尽表面诱变的相对蛋白质稳定性。与 25 个实验表征的冷休克蛋白突变体的比较显示，平均相关性为 0.86。该模型在重现 RNase T1 的实验 D49A 和 D49H 突变体稳定性时也具有定量准确性。这项工作代表了首次对可能通过优化表面静电赋予嗜温蛋白质热稳定性的突变体候选物进行全面的计算机筛选。系统的单突变体，然后是双突变体，筛选产生了有限数量的突变体结构，显示出适合后续实验表征的显着稳定性增益。
Recently, there have been several experimental reports of proteins displaying appreciable stability gains through mutation of one or two amino acid residues. Here, we employ a simple theoretical model to quickly screen mutant structures for increased thermostability through optimization of the protein's electrostatic surface. Our results are able to reproduce the experimental observation that elimination of like-charge repulsions and creation of opposite-charge attractions on the protein surface is an efficient method to confer thermostability to a mesophilic protein. Using Poisson-Boltzmann electrostatics, we calculate relative protein stabilities for the exhaustive surface mutagenesis of the cold shock, RNase T1, and CheY proteins. Comparison with 25 experimentally characterized cold shock protein mutants reveals an average correlation of 0.86. The model is also quantitatively accurate when reproducing the experimental D49A and D49H mutant stabilities of RNase T1. This work represents the first comprehensive in silico screening of mutant candidates likely to confer thermostability to mesophilic proteins through optimization of surface electrostatics. Systematic single mutant, followed by double mutant, screening yields a limited number of mutant structures displaying significant stability gains suitable for subsequent experimental characterization.