S蛋白(PS)是一种维生素K依赖性糖蛋白,是激活C蛋白的一种辅助因子。先天性PS缺乏可引起家族性静脉血栓性疾病:获得性PS缺乏(如妊娠、狼疮或应用口服避孕药)可增加血栓栓塞性疾病的危险。上述情况表明,PS的生理作用与凝血过程有关。故PS是存在于血浆中的一种天然抗凝剂。 PS在血浆中有两种存在形式,一种是游离的PS,另一种是与C_4b结合蛋白(C_4bBP)形成的复合物。游离形式的PS有抗凝活性,而结合形式的 S protein (PS) is a vitamin K-dependent glycoprotein that is a cofactor for activating protein C Congenital PS deficiency can cause familial venous thrombosis: Acquired PS deficiency (such as pregnancy, lupus, or the use of oral contraceptives) increases the risk of thromboembolic disease. The above situation shows that the physiological role of PS and the coagulation process. So PS is a natural anticoagulant present in the plasma. PS exists in plasma in two forms, one is free PS and the other is a complex with C_4b binding protein (C_4bBP). The free form of PS has anticoagulant activity in combination with the form