Abstract:

A new model of enzymatic synthesis of γ-D-Glu-L-Trp（SCV-07）from D-glutamine and L-tryptophan was developed.The Km and Kcat of transpeptidation and enzymatic hydrolysis of product (presented as K′_m and K′_cat) were determined as Km=5.11 mmol·L^-1, K_cat =3.92 mmol·min^-1, K′_m=2.31 mmol·L^-1 and K′_cat=1.46 mmol·min^-1.The sequential mechanism was used to describe the rate of transpeptidation，and the model parameters were optimized.The enzymatic synthesis of γ-D-glutamyl-L-tryptophan was investigated to verify the model.Good agreement between experimental data and calculations was obtained.The total relative errors of experimental data and calculations were less than 5%.

Key words:

γ-谷氨酰转肽酶, 反应机理, γ-D-Glu-L-Trp, 动力学模型

摘要：

以酶法合成γ-D-glutamyl-L-tryptophan (γ-D-Glu-L-Trp)为研究体系，采用D-谷氨酰胺为γ-谷氨酰基供体，L-色氨酸为受体，测定得到了转肽反应的米氏常数（K _m）为5.11 mmol·L^-1，催化常数（K_cat）为3.92 mmol·min^-1，γ-D-Glu-L-Trp的水解反应米氏常数（K′_m）为2.31 mmol·L^-1，催化常数（K′_cat）为1.46 mmol·min^-1。采用顺序反应机制建立了酶法制备γ-D-Glu-L-Trp的过程动力学模型，并进行了参数优化。经验证，所建模型可准确预测该体系中的反应进程，模型数值解与实验值的平均相对误差小于5%。

关键词:

γ-谷氨酰转肽酶, 反应机理, γ-D-Glu-L-Trp, 动力学模型