Christensen U
Biochim Biophys Acta. 1977 Apr 12;481(2):638-47. doi: 10.1016/0005-2744(77)90297-2.
Initial velocities for the urokinase (EC 3.4.99.26)-catalysed conversion of glutamic acid plasminogen to plasmin (EC 3.4.21.7) have been determined at various urokinase and glutamic acid plasminogen concentrations. As has been found for the corresponding reaction with lysine plasminogen this conversion obeys the Michaelis rate equation. The apparent Michaelis constants are of the same order of magnitude for lysine and glutamic acid plasminogens. The difference in conversion rates for the reactions has been shown to be connected with their having different catalytic constants. The data were analysed according to two reaction schemes, in one of which only one peptide bond is split during the glutamic acid plasminogen-plasmin conversion and in the other of which the cleavage of two peptide bonds with the obligatory formation of an intermediate plasminogen is assumed. The results favour the former.
已测定在不同尿激酶和谷氨酸纤溶酶原浓度下，尿激酶（EC 3.4.99.26）催化谷氨酸纤溶酶原转化为纤溶酶（EC 3.4.21.7）的初始速度。正如在赖氨酸纤溶酶原的相应反应中所发现的那样，这种转化遵循米氏速率方程。赖氨酸和谷氨酸纤溶酶原的表观米氏常数处于相同的数量级。已表明反应转化率的差异与其具有不同的催化常数有关。根据两种反应方案对数据进行了分析，其中一种方案是在谷氨酸纤溶酶原 - 纤溶酶转化过程中仅一个肽键被裂解，另一种方案假定裂解两个肽键并必然形成中间纤溶酶原。结果支持前者。
