Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180, USA.
Nat Commun. 2017 Feb 7;8:14561. doi: 10.1038/ncomms14561.
Hydrostatic pressure is an important environmental variable that plays an essential role in biological adaptation for many extremophilic organisms (for example, piezophiles). Increase in hydrostatic pressure, much like increase in temperature, perturbs the thermodynamic equilibrium between native and unfolded states of proteins. Experimentally, it has been observed that increase in hydrostatic pressure can both increase and decrease protein stability. These observations suggest that volume changes upon protein unfolding can be both positive and negative. The molecular details of this difference in sign of volume changes have been puzzling the field for the past 50 years. Here we present a comprehensive thermodynamic model that provides in-depth analysis of the contribution of various molecular determinants to the volume changes upon protein unfolding. Comparison with experimental data shows that the model allows quantitative predictions of volume changes upon protein unfolding, thus paving the way to proteome-wide computational comparison of proteins from different extremophilic organisms.
静水压力是一种重要的环境变量，对许多极端微生物（例如嗜压生物）的生物适应性起着至关重要的作用。静水压力的增加，就像温度的升高一样，会破坏蛋白质天然状态和展开状态之间的热力学平衡。实验观察到，静水压力的增加既可以增加也可以降低蛋白质的稳定性。这些观察结果表明，蛋白质展开时的体积变化可能是正的也可能是负的。过去 50 年来，这种体积变化符号差异的分子细节一直困扰着该领域。在这里，我们提出了一个全面的热力学模型，对蛋白质展开时体积变化的各种分子决定因素的贡献进行了深入分析。与实验数据的比较表明，该模型允许对蛋白质展开时的体积变化进行定量预测，从而为来自不同极端微生物的蛋白质的全蛋白质组计算比较铺平了道路。
