LiMuti C, Bell J E
Biochem J. 1983 Apr 1;211(1):99-107. doi: 10.1042/bj2110099.
The kinetic mechanism of glutamate dehydrogenase with the monocarboxylic substrate norvaline was examined by using initial-rate steady-state kinetics and inhibition kinetics. To a first approximation the reaction mechanism can be described as a rapid-equilibrium random-order one. Binding synergism between the monocarboxylic substrate and coenzyme is not observed. Dissociation constants for NAD+ and 2-oxoglutarate calculated from the kinetic data assuming a rapid-equilibrium random-order model are in good agreement with independently obtained estimates. Lineweaver-Burk plots with varied norvaline concentration are not strictly linear, and it is concluded that a steady-state random-order model more accurately reflects the observed kinetics with norvaline as substrate.
通过使用初速率稳态动力学和抑制动力学,研究了谷氨酸脱氢酶与单羧酸底物正缬氨酸的动力学机制。初步估算,该反应机制可描述为快速平衡随机顺序机制。未观察到单羧酸底物与辅酶之间的结合协同作用。根据动力学数据,假设为快速平衡随机顺序模型计算得到的NAD⁺和2-氧代戊二酸的解离常数,与独立获得的估计值高度吻合。以不同正缬氨酸浓度绘制的林-贝氏图并非严格呈线性,由此得出结论,稳态随机顺序模型能更准确地反映以正缬氨酸为底物时所观察到的动力学。