factor X -> factor Xa + factor X activation peptide (TF:F7a catalyst)

Factor VIIa, bound to tissue factor at the endothelial cell surface (the "extrinsic tenase complex"), catalyzes the formation of activated factor X with high efficiency. The amino terminal part of the heavy chain of factor X, the factor X activation peptide, is released. (This peptide has no known function.)

因子VIIa与内皮细胞表面结合的组织因子（外源凝血酶复合物）相结合，高效催化活化因子X的形成。因子X重链的氨基端部分，即因子X活化肽，被释放。该肽段目前尚无已知功能。