Energetics of ribonuclease T1 structure.
Energetics of ribonuclease T1 structure.
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核糖核酸酶 T1 结构的能量学。
DOI：
10.1021/bi00177a023
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发表时间：
1994
期刊：
影响因子：
2.9
通讯作者：
Privalov,PL
中科院分区：
文献类型：
--
作者：
Yu,Y;Makhatadze,GI;Pace,CN;Privalov,PL
摘要：用差示扫描量热法研究了核糖核酸酶T1的两种异构体（Gln 25和Lys 25）在不同溶剂中的热变性的能量学。已经表明，两种形式的RNA酶T1的热转变强烈地受缓慢动力学的影响，这导致转变与简单的两态模型的明显偏差。通过降低加热速率或提高转变温度，RNase的变性接近平衡的两态转变。这允许确定表征天然结构展开的热力学参数。这些热力学参数与蛋白质的结构特征相关。对RNase T1稳定性的不同贡献的分析表明，货车范德华力和氢键是蛋白质构象稳定性的主要贡献者，不同力对蛋白质分子稳定性的贡献仍然是有争议的主题（Creighton，1991）。解决这个问题的方法之一是分析各种蛋白质，并将指定天然结构稳定性的热力学参数（即其展开）与蛋白质的结构特征相关联（Makhatadze & Privalov，1993; Privalov & Makhatadze，1993）。这种分析的成功在很大程度上取决于蛋白质的选择，其大小，三维结构的可用性，
Revised Manuscript Received January 10, 1994® abstract: The energetics of thermal denaturation of two isoforms of ribonuclease Tl (Gln25 and Lys25) in various solvents have been studied by differential scanning calorimetry. It has been shown that the thermal transition of both forms of RNase Tl is strongly affected by slow kinetics, which cause an apparent deviation of the transition from a simple two-state model. By decreasing the heating rate or increasing the transition temperature, the denaturation of RNase approaches an equilibrium two-state transition. This permits determination of the thermodynamic parameters characterizingunfolding of the native structure. These thermodynamic parameters were correlated with the structural features of protein. Analysis of different contributions to the stability of RNase Tl shows that van der Waals interactions and hydrogen bonding are the major contributors to the conformational stability of the protein.The contribution of different forces to the stability of protein molecules is still the subject of controversy (Creighton, 1991). One of the ways to resolve this problem is to analyze a variety of proteins and to correlate the thermodynamic parameters specifying the stability of the native structure, ie, its unfolding, and thestructural features of proteins (Makhatadze & Privalov, 1993; Privalov & Makhatadze, 1993). Success in this analysis largely depends on the choice of protein, its size, the availabilityof a three-dimensional structure, the com-