Wiman B, Chmielewska J, Rånby M
J Biol Chem. 1984 Mar 25;259(6):3644-7.
A new specific and sensitive method for determination of tissue plasminogen activator (t-PA) in plasma samples has been used to demonstrate the presence of a fast inhibitor to t-PA in plasma. By adding [35S]Met internally labeled t-PA (Mr approximately 70,000) to plasma, we were able to demonstrate the rapid formation of a stable complex with an apparent molecular weight of about 115,000 as estimated by gel filtration. The complex was partially purified by immunoadsorbtion chromatography on insolubilized antibodies against porcine t-PA, and a molecular weight of about 120,000 was found by dodecyl sulfate-polyacrylamide gel electrophoresis. From the apparent molecular weight of the complex (120,000) and the molecular weight of t-PA (70,000), a molecular weight of about 50,000 would be expected for the inhibitor. However, gel filtration of inhibitor-rich plasma resulted in the appearance of a symmetrical peak of t-PA inhibitory activity with an apparent molecular weight of about 205,000. The reason for this discrepancy is not known, but several different models are possible.
一种用于测定血浆样本中组织型纤溶酶原激活物（t-PA）的新的特异性和灵敏性方法已被用于证明血浆中存在一种对t-PA的快速抑制剂。通过向血浆中加入内部标记有[35S]甲硫氨酸的t-PA（分子量约70,000），我们能够证明形成了一种稳定的复合物，通过凝胶过滤估计其表观分子量约为115,000。该复合物通过在针对猪t-PA的固定化抗体上进行免疫吸附色谱法进行部分纯化，并且通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳发现其分子量约为120,000。根据复合物的表观分子量（120,000）和t-PA的分子量（70,000），预计抑制剂的分子量约为50,000。然而，对富含抑制剂的血浆进行凝胶过滤时，出现了一个表观分子量约为205,000的t-PA抑制活性的对称峰。这种差异的原因尚不清楚，但有几种不同的模型是可能的。
