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蛋白质Z依赖性蛋白酶抑制物(ZPI)是最近从血浆中分离出的一个分子量约为72 kD的糖蛋白,反应中心含有一酪氨酸,属于丝氨酸蛋白酶抑制物超家族成员。ZPI可抑制FⅩa,但速率较慢;在氨基磷脂及Ca~(2+)存在的条件下,ZPI与蛋白质Z(PZ)形成复合物,其抑制作用可提高1000倍以上。PZ的生物学意义长期未明,至目前为止认为它的基本功能是作为ZPI的辅因子而抑制FXa。ZPI在没有PZ、磷脂及Ca~(2+)存在条件下对FⅪa也有一定的抑制作用。在与FⅩa、FⅪa作用过程中,ZPI的活性逐渐消耗。在FV Leiden的小鼠模型中,如同时伴有PZ缺乏则显现明显的高凝状态,目前认为PZ/ZPI或ZPI在体内不但调节凝血过程,而且可能参与纤溶或炎症反应的调控。ZPI和/或PZ缺乏症对人类血栓形成的影响值得重视。
The protein Z-dependent protease inhibitor (ZPI) is a recently isolated glycoprotein of about 72 kD in plasma containing tyrosine, a member of the serine protease inhibitor superfamily. ZPI can inhibit F Xa but its rate is slow. In the presence of aminophospholipids and Ca 2+, ZPI can form a complex with protein Z (PZ), and the inhibition can be increased more than 1000 folds. The biological significance of PZ has long been unknown and so far its basic function is thought to be to inhibit FXa as a cofactor for ZPI. ZPI also inhibited FXIa in the absence of PZ, phospholipid and Ca 2+. In the F Xa, F XIa role in the process, ZPI activity gradually consumed. In the FV Leiden mouse model, PZ / ZPI or ZPI is currently considered to not only regulate the process of coagulation, but also participate in the regulation of fibrinolysis or inflammatory reaction, as it is accompanied by PZ deficiency. The impact of ZPI and / or PZ deficiency on human thrombosis deserves attention.