The primary inhibitor of plasmin in human plasma.
The primary inhibitor of plasmin in human plasma.
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人血浆中纤溶酶的主要抑制剂。
DOI：
10.1042/bj1590545
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
I. Clemmensen
中科院分区：
文献类型：
--
作者：
By Sten Mullertz;I. Clemmensen
用亲和层析法从尿激酶激活的人血浆中分离出纤溶酶和抑制剂之间的复合物。该复合物不与血浆中任何已知蛋白酶抑制剂的抗体反应。制备了抗该复合物的兔抗血清。它含有抗纤溶酶原+纤溶酶和α 2蛋白的抗体。通过交叉免疫电泳的α 2蛋白质被证明与纤溶酶形成复合物，当产生的尿激酶在血浆中，并与纯化的纤溶酶。通过Sephadex G-200凝胶过滤以约KD洗脱α 2蛋白。0.35，不同于血浆中的其他纤溶酶抑制剂，并且对应于约75000的表观相对分子质量（Mr）。通过十二烷基硫酸钠/聚丙烯酰胺凝胶电泳，发现该复合物的Mr约为。130000.还原后的复合物的蛋白质的两个主要带，观察到，与先生，约72000和66000，可能代表纤溶酶轻链和乙酰化酶重链的酰基酶复合物，和纤溶酶重链。Mr 9000的弱带可能是一条轻链。该抑制剂被部分纯化并用于滴定已知活性位点浓度的纯化纤溶酶。该抑制剂与纤溶酶结合迅速而强烈。假设等摩尔结合比，正常人血浆中活性抑制剂的浓度估计为1.1 μ mol/l。约0.3的抗原抑制蛋白的分数似乎是功能上无活性的。在血浆中，纤溶酶主要与抑制剂结合。只有在其饱和后，纤维蛋白原和纤维蛋白才发生溶解，并出现纤溶酶和α 2巨球蛋白之间的复合物。
A complex between plasmin and an inhibitor was isolated by affinity chromatography from urokinase-activated human plasma. The complex did not react with antibodies against any of the known proteinase inhibitors in plasma. A rabbit antiserum against the complex was produced. It contained antibodies agianst plasminogen+plasmin and an alpha2 protein. By crossed immunoelectrophoresis the alpha2 protein was shown to form a complex with plasmin, when generated by urokinase in plasma, and with purified plasmin. The alpha2 protein was eluted by Sephadex G-200 gel filtration with KD approx. 0.35, different from the other inhibitors of plasmin in plasma, and corresponding to an apparent relative molecular mass (Mr) of about 75000. By sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the Mr of the complex was found to be approx. 130000. After reduction of the complex two main bands of protein were observed, with Mr, about 72000 and 66000, probably representing an acyl-enzyme complex of plasmin-light chain and inhibitor-heavy chain, and a plasmin-heavy chain. A weak band with Mr 9000 was possibly an inhibitor-light chain. The inhibitor was partially purified and used to titrate purified plasmin of known active-site concentration. The inhibitor bound plasmin rapidly and strongly. Assuming an equimolar combining ratio, the concentration of active inhibitor in normal human plasma was estimated to be 1.1 mumol/1. A fraction about 0.3 of the antigenic inhibitor protein appeared to be functionally inactive. In plasma, plasmin is primarily bound to the inhibitor. Only after its saturation does lysis of fibrinogen and fibrin occur and a complex between plasmin and alpha2 macroglobulin appear.