Identification and characterization of the factor Va binding site on prothrombin.

当血管损伤时，凝血系统被激活，以停止失血，开始伤口愈合和损伤修复的过程。凝血系统由酶复合体组成，这些酶复合体依次激活下游酶复合体。一个共同的特征是，这些复合体都含有1)酶、2)辅因子、3)钙和4)带负电荷的细胞表面。在所有情况下，即使酶能够单独作用于底物，其辅因子的存在也会使反应增强10%

Upon vascular injury, the coagulation system is activated in order to stop the blood loss and begin the process of wound healing and damage repair. The clotting system consists of enzyme complexes that sequentially activate downstream enzyme complexes. One characteristic in common is that these complexes all contain 1) enzyme, 2) cofactor, 3) calcium, and 4) negatively charged cell surface. In all instances, even though the enzyme is able to act on the substrate alone, the presence of its cofactor enhances the reaction by 10