SNase R在胍变性过程中构象与活力变化的比较  

COMPARISON OF THE ACTIVITY AND CONFORMATION CHANGES OF SNase R DURING GUANIDINE DENATURATION

作　　者：张广发[1] 静国忠[1] 

机构地区：[1]中国科学院生物物理研究所,北京100101

出　　处：《生物物理学报》1993年第2期186-190,共5页Acta Biophysica Sinica

摘　　要：以紫外差光谱、荧光光谱为监测手段对金黄色葡萄球菌核酸酶类似物(SNase R)在胍溶液中构象与活力变化进行了比较.SNase R在Llmol L0.8mol L和0.5mol L胍溶液变性时变性过程均为两个一级反应,但是酶在上述胍浓度下失活的速度远快于构象变化的速度:酶在同一胍浓度下活力丧失的程度也远快于构象变化的程度.上述结果表明:SNase R的活性部位可能位于柔性较大的区域.The correlation of the activity and conformation changes of SNase R during denaturation by different concentrations of guanidine hydrochloride has been studied by fluorescence and ultraviolet difference sppectrosoopic methods. The denaturation processes of SNase R consist of two first-order reactions in 1.1mol/L. 0.8mol/L. and 0.5mol/L guanidium. but the inactivation process of SNase R were too fast to follow at the same conditions. Moreover, when the denaturation reached equilibrium state, the extent of inactivation of SNase R was much greater than that of either UV difference absorbance or fluorescence intensity changes at the same concentration of guanidium. It seems to suggest that the active site of the enzyme is in a flexible region.

关 键 词：胍变性 金黄葡萄球菌 核酸酶 

分 类 号：Q71[生物学—分子生物学]