Cascante M, Cortés A
Departament de Bioquimica i Fisiologia, Facultat de Química, Universitat de Barcelona, Spain.
Biochem J. 1988 Mar 15;250(3):805-12. doi: 10.1042/bj2500805.
The kinetic behaviour of chicken liver and turkey liver aspartate aminotransferases (L-aspartate:2-oxoglutarate aminotransferase, EC 2.6.1.1) was studied. Steady-state data were obtained from a wide range of concentrations of substrates and product L-glutamate. The data were fitted by rational functions of degree 1:1, 1:2 and 2:2 with respect to substrates and 0:1, 1:1, 0:2 and 1:2 with regard to product (L-glutamate), by using a non-linear regression program that guarantees the fit. The goodness of fit was improved by the use of a computer program that combines model discrimination parameter refinement and sequential experimental design. It was concluded that aspartate aminotransferase requires a minimum velocity equation of degree 2:2 for L-aspartate, 2:2 for 2-oxoglutarate and 1:2 for L-glutamate. Finally, a plausible kinetic mechanism that justifies these experimental results is proposed.
研究了鸡肝和火鸡肝天冬氨酸转氨酶（L-天冬氨酸：2-氧代戊二酸转氨酶，EC 2.6.1.1）的动力学行为。从广泛的底物和产物L-谷氨酸浓度中获得稳态数据。通过使用保证拟合的非线性回归程序，将数据拟合为底物方面的1:1、1:2和2:2次有理函数，以及产物（L-谷氨酸）方面的0:1、1:1、0:2和1:2次有理函数。通过使用结合模型判别参数细化和顺序实验设计的计算机程序，拟合优度得到了提高。得出的结论是，天冬氨酸转氨酶对L-天冬氨酸需要2:2次的最小速度方程，对2-氧代戊二酸需要2:2次，对L-谷氨酸需要1:2次。最后，提出了一个合理的动力学机制来解释这些实验结果。
