Wong N S, Lau H K
Thromb Res. 1984 Feb 15;33(4):389-99. doi: 10.1016/0049-3848(84)90078-1.
A cytosolic fraction of human small intestine was prepared. It contained esterase activity toward N-alpha-acetyl-lysine-methyl ester and amidolytic activities toward substrates S-2238, S-2288 and S-2251. In addition there was present a plasminogen activator activity which could cleave plasminogen to produce plasmin and the plasmin hydrolysed the same chromogenic substrates. Plasmin generation was also followed by a time-dependent hydrolysis of 125-I labeled plasminogen or monitored by fibrin-agar plate. The plasminogen activator was related to urinary urokinase immunologically. Anti-urokinase IgG cross-reacted with cytosolic fraction in double immunodiffusion. When the cytosolic fraction was electrophoresed in discontinuous polyacrylamide gel, two regions of hydrolytic activity toward the urokinase-specific substrate S-2444 were found. The activity of one of these regions could be completely inhibited by anti-urokinase while the other was not. The plasminogen activator was partially purified by ammonium sulfate precipitation and Concanavalin A-bound Sepharose chromatography.
制备了人小肠的胞质部分。它含有对N-α-乙酰赖氨酸甲酯的酯酶活性以及对底物S-2238、S-2288和S-2251的酰胺分解活性。此外，还存在一种纤溶酶原激活剂活性，它可以裂解纤溶酶原产生纤溶酶，并且纤溶酶可水解相同的显色底物。纤溶酶的产生还伴随着125-I标记的纤溶酶原的时间依赖性水解，或通过纤维蛋白-琼脂平板进行监测。纤溶酶原激活剂在免疫学上与尿激酶相关。抗尿激酶IgG在双向免疫扩散中与胞质部分发生交叉反应。当胞质部分在不连续聚丙烯酰胺凝胶中进行电泳时，发现了对尿激酶特异性底物S-2444的两个水解活性区域。其中一个区域的活性可被抗尿激酶完全抑制，而另一个区域则不能。通过硫酸铵沉淀和伴刀豆球蛋白A结合的琼脂糖凝胶色谱法对纤溶酶原激活剂进行了部分纯化。
