Isolation and characterization of urokinase from human plasma.
Isolation and characterization of urokinase from human plasma.
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从人血浆中分离和表征尿激酶。
DOI：
10.1016/s0021-9258(19)81106-7
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
E. Reich
中科院分区：
文献类型：
--
作者：
T. Wun;W. Schleuning;E. Reich
长期以来人们一直认为血浆中存在纤溶系统激活剂，但从未通过分离特征性且生理上合理的酶来令人信服地证明这一点。先前鉴定的血浆纤溶酶原激活剂的催化效率较低，这使得它们的生理意义不确定，促使我们寻找其他血浆酶，尤其类似于有效的尿激活剂尿激酶。我们在这里报告了人血浆中类似尿激酶活性的检测，以及从全血浆蛋白组分中分离出该酶。纯化的酶在以下方面与人尿尿激酶的 53,000 道尔顿成分没有区别：十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、双重免疫扩散、氨基酸分析、二维胰蛋白酶肽图、合成肽底物的催化效率和抑制剂谱的表观 Mr。结果表明（a）该酶以潜在形式存在于血浆中，其性质仍有待确定；（b）循环浓度至少为 5 至 10 微克/升，足以产生大量的纤溶酶，特别是如果激活在某种程度上受到特定位点定位的限制。
The presence of activators of the fibrinolytic system in blood plasma has been assumed for a long time but never convincingly documented by the isolation of characterized and physiologically plausible enzymes. The low catalytic efficiency of previously identified plasma plasminogen activators, which has made their physiological significance uncertain, prompted us to search for other plasma enzymes, resembling especially the potent urinary activator, urokinase. We report here the detection of a urokinase-like activity in human plasma, and the isolation of the enzyme from whole plasma protein fractions. The purified enzyme is indistinguishable from the 53,000-dalton components of human urinary urokinase in the following respects: apparent Mr on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, double immunodiffusion, amino acid analysis, two-dimensional tryptic peptide maps, catalytic efficiency with synthetic peptide substrates, and inhibitor spectrum. The results suggest (a) that the enzyme is present in plasma in a latent form whose nature remains to be defined, and (b) that the circulating concentration is at least 5 to 10 microgram/liter, and sufficient to generate substantial levels of plasmin, particularly if activation were somehow confined by localization at specific sites.