THERMODYNAMIC AND KINETIC EXAMINATION OF PROTEIN STABILIZATION BY GLYCEROL
THERMODYNAMIC AND KINETIC EXAMINATION OF PROTEIN STABILIZATION BY GLYCEROL
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DOI：
10.1021/bi00519a024
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发表时间：
1981-01-01
期刊：
影响因子：
2.9
通讯作者：
TIMASHEFF, SN
中科院分区：
文献类型：
--
作者：
GEKKO, K;TIMASHEFF, SN
用差示分光光度法分别在293和287 nm处测定了浓甘油对胰凝乳蛋白酶原和核糖核酸酶热转变的影响。对于这两种蛋白质，甘油的加入提高了转变温度[Tm]，RNA酶的Tm增加大于胰凝乳蛋白酶原。这种变性自由能的增加似乎主要反映了熵变的减少。根据Wyman连接方程的分析表明，对于两种蛋白质，甘油从蛋白质结构域的排除在变性时增加，即，当蛋白质相对于天然结构展开时，甘油的化学势甚至变得更正。这提供了热力学稳定自由能。的缓慢展开反应的动力学检查的结果是一致的概念，即优先排除甘油有关，至少部分地，以增强溶剂排序。
The effect of concentrated glycerol on the thermal transitions of chymotrypsinogen and RNase was examined by differential spectrophotometry at 293 and 287 nm, respectively. For both proteins addition of glycerol raises the transition temperature, [Tm], the increase in Tm being greater for RNase than for chymotrypsinogen. This increase in the free energy of denaturation appears to reflect primarily a decrease in the entropy change. Analysis in terms of the Wyman linkage equation shows that, for both proteins, the exclusion of glycerol from the protein domain increases on denaturation, i.e., the chemical potential of glycerol becomes even more positive when the protein unfolds relative to the native structure. This provides the thermodynamic stabilization free energy. Results of the kinetic examination of the slow unfolding reaction are consistent with the concept that the preferential exclusion of glycerol is related, at least in part, to enhanced solvent ordering.