Stief T W, Martin E, Digon J, Martin-Noya A, Parody R, Rodriguez J M
Department of Hematology, University Hospital Virgen del Rocío, University of Seville, Spain.
Thromb Res. 1990 Jul 15;59(2):351-61. doi: 10.1016/0049-3848(90)90137-2.
Single chain- urokinase (scu-PA), in contrast to two chain urokinase, is a physiological plasminogen activator of fibrin selectivity. The mechanism of selective fibrinolysis of scu- PA has not been clarified up to now. This study has shown that fibrin selectivity might involve oxidative processes. Binding studies with immobilized oxidized fibrinogen degradation products (FDP) demonstrated higher affinity of scu-PA to oxidized than to unmodified FDP. The fibrin(ogen) domain responsible for this oxidant mediated increase of scu-PA affinity is localized in the D-subunit of fibrin(ogen). Thus, experimental data upon the interaction of scu-PA with fibrin(ogen) using oxidized and I- labelled fibrin(ogen) might be interpreted with caution: the oxidized product may behave in a distinct manner than the unoxidized, native, one. Activated leukocytes release large amounts of scu-PA and of oxidants of the chloramine type. The oxidants could contribute significantly to fibrinolysis and proteolysis in areas of inflammation, preparing fibrin for its specific degradation. The present data support the concept of an involvement of oxidative processes in the fibrinolytic pathway.
与双链尿激酶相比，单链尿激酶（scu-PA）是一种具有纤维蛋白选择性的生理性纤溶酶原激活剂。迄今为止，scu-PA选择性纤维蛋白溶解的机制尚未阐明。本研究表明，纤维蛋白选择性可能涉及氧化过程。与固定化氧化纤维蛋白原降解产物（FDP）的结合研究表明，scu-PA对氧化型FDP的亲和力高于未修饰的FDP。负责这种氧化剂介导的scu-PA亲和力增加的纤维蛋白（原）结构域位于纤维蛋白（原）的D亚基中。因此，使用氧化型和I标记的纤维蛋白（原）对scu-PA与纤维蛋白（原）相互作用的实验数据可能需要谨慎解释：氧化产物的行为可能与未氧化的天然产物不同。活化的白细胞释放大量的scu-PA和氯胺类氧化剂。这些氧化剂可能在炎症区域的纤维蛋白溶解和蛋白水解中起重要作用，为纤维蛋白的特异性降解做好准备。目前的数据支持氧化过程参与纤维蛋白溶解途径的概念。
