REGENERATION OF BOVINE PANCREATIC RIBONUCLEASE-A .3. DEPENDENCE ON THE NATURE OF THE REDOX REAGENT
REGENERATION OF BOVINE PANCREATIC RIBONUCLEASE-A .3. DEPENDENCE ON THE NATURE OF THE REDOX REAGENT
复制标题
DOI：
10.1021/bi00061a029
复制
发表时间：
1993-03-16
期刊：
影响因子：
2.9
通讯作者：
SCHERAGA, HA
中科院分区：
文献类型：
--
作者：
ROTHWARF, DM;SCHERAGA, HA
单硫醇试剂如氧化型和还原型谷胱甘肽（分别为GSSG和GSH）与蛋白质硫醇形成稳定的混合二硫化物，而二硫醇试剂如氧化型和还原型二硫苏糖醇（分别为DTT（ox）和DTT（red））则不会。混合二硫键稳定性的巨大差异反映在GSSG/GSH的蛋白质二硫键形成和还原速率远高于DTT（ox）/DTT（red）。对于二硫苏糖醇，稳态中中间物质的浓度取决于氧化还原电位，即，[DTT（ox）]/[DTT（red）]比值，而不是这些试剂的绝对浓度。对于谷胱甘肽，氧化还原电位以及稳态中中间物质的浓度取决于[GSSG]/[GSH]2比值;因此，与二硫苏糖醇相反，对于谷胱甘肽，浓度的绝对值确实影响稳态浓度。因此，牛胰腺核糖核酸酶A的再生途径取决于氧化还原试剂的性质以及使用它们时的氧化还原电位。GSSG/GSH的使用有利于多个再生途径，而DTT（ox）/DTT（red）的使用有利于通过较少的途径再生。这些概念也说明了牛胰蛋白酶抑制剂的再生途径的文献数据的分析。
Monothiol reagents such as oxidized and reduced glutathione (GSSG and GSH, respectively) form stable mixed disulfides with protein thiols while dithiol reagents such as oxidized and reduced dithiothreitol (DTT(ox) and DTT(red), respectively) do not. This large difference in the stabilities of the mixed disulfides is reflected in much greater rates of formation and reduction of protein disulfide bonds with GSSG/GSH than with DTT(ox)/DTT(red). With dithiothreitol, the concentrations of intermediate species in the steady state depend on the redox potential, i.e., on the [DTT(ox)]/[DTT(red)] ratio, and not on the absolute concentrations of these reagents. With glutathione, the redox potential and hence the concentrations of intermediate species in the steady state depend on the [GSSG]/[GSH]2 ratio; hence, with glutathione, in contrast to dithiothreitol, the absolute values of the concentrations do affect the steady-state concentrations. Consequently, the regeneration pathways of bovine pancreatic ribonuclease A depend on the nature of the redox reagent as well as the redox potential at which they are used. The use of GSSG/GSH favors multiple regeneration pathways, while the use of DTT(ox)/DTT(red) favors regeneration through fewer pathways. These concepts are also illustrated by an analysis of literature data for the regeneration pathways of bovine pancreatic trypsin inhibitor.