论文部分内容阅读
运用荧光光谱方法研究了牛肝Ｌ－谷氨酸脱氢酶（ＧＤＨ）在压力下的解离。研究表明，在２ｋｂａｒ时ＧＤＨ由六聚体解离成亚基，标准解离体积变化为－２９３ｍｌ／ｍｏｌ，解离自由能为４８ｋｃａｌ／ｍｏｌ（１０℃）。ＧＤＨ在压力下的解离还显示出异常的浓度依赖性，表明在天然寡聚蛋白的布居中存在着自由能不同的单体聚合。不同温度下的ＧＤＨ解离研究结果表明，由亚基－六聚体的聚合是一熵增驱动过程。ｂｉｓ－ＡＮＳ存在时观察到的现象，暗示谷氨酸脱氢酶的亚基解离过程中发生了构象漂移（ｃｏｎｆｏｒｍａｔｉｏｎａｌｄｒｉｆｔ）。此外还研究了底物结合对解离的影响
Fluorescence spectroscopy was used to study the dissociation of bovine liver L-glutamate dehydrogenase (GDH) under pressure. Studies have shown that at 2kbar, GDH dissociates from hexamers into subunits with a standard dissociation volume of -293 ml / mol and a dissociation free energy of 48 kcal / mol (10 ° C). Dissociation of GDH under pressure also showed an anomalous concentration dependence, suggesting that there are free-energy monomer polymerizations in the native oligomeric protein population. The results of GDH dissociation at different temperatures show that the polymerization by subunit-hexamer is an entropy-driven process. The phenomenon observed when bis-ANS is present suggests that conformational drift occurs during dissociation of the glutamate dehydrogenase subunit. In addition, the effect of substrate binding on dissociation was also studied