McCarthy A D, Johnson P, Tipton K F
Biochem J. 1981 Oct 1;199(1):235-8. doi: 10.1042/bj1990235.
The concentration-dependent aggregation behaviour of purified ox liver and brain glutamate dehydrogenase preparations was compared with that of commercially-obtained preparations of the liver enzyme, which have recently been shown to have suffered proteolytic cleavage. Although there were no significant differences in these effects, the presence of 3 mM-GTP and 3 mM-NADH had markedly different effects on the two types of preparation. In this situation, at higher protein concentrations the commercially obtained preparations existed in a higher degree of aggregation than those which had not suffered proteolysis. Studies of the effects of GTP and NADH concentrations on the sedimentation coefficients at a fixed enzyme concentration suggested these effects to be largely due to differences in the affinities of the two preparations for nucleotides.
将纯化的牛肝和牛脑谷氨酸脱氢酶制剂的浓度依赖性聚集行为与市售的肝酶制剂进行了比较，最近发现市售的肝酶制剂受到了蛋白水解切割。尽管这些作用没有显著差异，但3 mM - GTP和3 mM - NADH的存在对这两种制剂有明显不同的影响。在这种情况下，在较高蛋白质浓度下，市售制剂的聚集程度高于未发生蛋白水解的制剂。在固定酶浓度下研究GTP和NADH浓度对沉降系数的影响表明，这些影响主要是由于两种制剂对核苷酸亲和力的差异。
