Rogovskiĭ S P, Mel'nichuk D A
Ukr Biokhim Zh (1978). 1982 Jul-Aug;54(4):418-23.
The initial rate of direct and reverse reactions catalyzed by crystalline NAD(P)+-dependent glutamate dehydrogenase from bovine liver as well as Km, V and some other kinetic parameters were studied as affected by carbonic acid in different concentrations (0, 10, 20, 40, 60 mM) at p Hof the incubation media 6.4-9.1. It is shown that the dependence of the initial rate on pH both of the direct and reverse reactions varies with the carbonic acid concentration. In the pH alkaline range the glutamate dehydrogenase activity is inhibited in the presence of a mixture of HCO3 and pCO2 (soluble carbonic acid) and in the acid range pH it has a tendency to increase. The pKb value lowers by an order and the pKa value remains practically unchanged. The interaction of pCO2 with E-amino group of the lysin residue in the enzyme molecule accompanied by formation of carbamate is supposed to be possible. The bicarbonate ion may also affect the enzyme.
研究了牛肝中结晶态NAD(P)+依赖型谷氨酸脱氢酶催化的正向和逆向反应的初始速率以及Km、V和其他一些动力学参数，这些参数受不同浓度（0、10、20、40、60 mM）碳酸的影响，孵育介质的pH为6.4 - 9.1。结果表明，正向和逆向反应的初始速率对pH的依赖性随碳酸浓度而变化。在pH碱性范围内，HCO3和pCO2（可溶性碳酸）混合物存在时，谷氨酸脱氢酶活性受到抑制，而在酸性pH范围内有增加的趋势。pKb值降低了一个数量级，pKa值基本保持不变。推测pCO2与酶分子中赖氨酸残基的E - 氨基相互作用并伴随氨基甲酸盐的形成是可能的。碳酸氢根离子也可能影响该酶。
