蛋白质活性和稳定性的 pH 最佳值。
On the pH-optimum of activity and stability of proteins.
机构信息
Computational Biophysics and Bioinformatics, Physics Department, Clemson University, Clemson, South Carolina 29634, USA.
出版信息
Proteins. 2010 Sep;78(12):2699-706. doi: 10.1002/prot.22786.
Biological macromolecules evolved to perform their function in specific cellular environment (subcellular compartments or tissues); therefore, they should be adapted to the biophysical characteristics of the corresponding environment, one of them being the characteristic pH. Many macromolecular properties are pH dependent, such as activity and stability. However, only activity is biologically important, while stability may not be crucial for the corresponding reaction. Here, we show that the pH-optimum of activity (the pH of maximal activity) is correlated with the pH-optimum of stability (the pH of maximal stability) on a set of 310 proteins with available experimental data. We speculate that such a correlation is needed to allow the corresponding macromolecules to tolerate small pH fluctuations that are inevitable with cellular function. Our findings rationalize the efforts of correlating the pH of maximal stability and the characteristic pH of subcellular compartments, as only pH of activity is subject of evolutionary pressure. In addition, our analysis confirmed the previous observation that pH-optimum of activity and stability are not correlated with the isoelectric point, pI, or with the optimal temperature.
生物大分子是为了在特定的细胞环境（亚细胞区室或组织）中执行其功能而进化的；因此，它们应该适应相应环境的生物物理特性，其中之一就是特征 pH 值。许多大分子特性都依赖于 pH 值，例如活性和稳定性。然而，只有活性在生物学上是重要的，而稳定性对于相应的反应可能并不关键。在这里，我们展示了在一组具有可用实验数据的 310 种蛋白质中，活性的 pH 最佳值（最大活性的 pH 值）与稳定性的 pH 最佳值（最大稳定性的 pH 值）之间存在相关性。我们推测，这种相关性是必需的，以允许相应的大分子能够耐受细胞功能不可避免的微小 pH 波动。我们的研究结果合理化了将最大稳定性 pH 值和亚细胞区室的特征 pH 值相关联的努力，因为只有活性 pH 值受到进化压力的影响。此外，我们的分析证实了先前的观察结果，即活性和稳定性的 pH 最佳值与等电点（pI）或最佳温度不相关。
Zotero 插件