Specificity constants of TGase-mediated transamidation.

0.2–0.8 μM mRuby2-Qtag test proteins and 5 mM Gly-OMe were reacted in the presence of 0.1 U TGase. Initial rates were measured over 20 min, using the GDH-coupled assay. Specificity constants were determined by fitting initial rate data to the Michaelis-Menten equation (see Materials and methods).将0.2~0.8 μM的mRuby2-Qtag检测蛋白与5 mM的Gly-OMe在0.1 U的转谷氨酰胺酶（TGase）存在下进行反应。采用谷氨酸脱氢酶（GDH）偶联测定法，在20分钟内测定初始反应速率。通过将初始速率数据拟合至米氏方程（Michaelis-Menten equation）以确定特异性常数（详见材料与方法）。