Goldsmith G H, Saito H, Ratnoff O S
J Clin Invest. 1978 Jul;62(1):54-60. doi: 10.1172/JCI109113.
Activation of plasminogen through surface-mediated reactions is well recognized. In the presence of kaolin, purified Hageman factor (Factor XII) changed plasminogen to plasmin, as assayed upon a synthetic amide substrate and by fibrinolysis. Kinetic studies suggested an enzymatic action of Hageman factor upon its substrate, plasminogen. Hageman factor fragments, at a protein concentration equivalent to whole Hageman factor, activated plasminogen to a lesser extent. These protein preparations were not contaminated with other agents implicated in surface-mediated fibrinolysis. Diisopropyl fluorophosphate treatment of plasminogen did not inhibit its activation by Hageman factor. These studies indicate that Hageman factor has a hitherto unsuspected function, the direct activation of plasminogen.
通过表面介导反应激活纤溶酶原已得到充分认识。在高岭土存在的情况下，经合成酰胺底物检测及纤维蛋白溶解检测，纯化的哈格曼因子（因子 XII）可将纤溶酶原转变为纤溶酶。动力学研究表明哈格曼因子对其底物纤溶酶原具有酶促作用。哈格曼因子片段在与完整哈格曼因子相当的蛋白质浓度下，对纤溶酶原的激活程度较小。这些蛋白质制剂未被其他与表面介导纤维蛋白溶解有关的因子污染。用二异丙基氟磷酸处理纤溶酶原并不抑制其被哈格曼因子激活。这些研究表明，哈格曼因子具有一种迄今未被怀疑的功能，即直接激活纤溶酶原。
