Tissue factor accelerates the activation of coagulation factor VII: the role of a bifunctional coagulation cofactor.
One way in which coagulation may be initiated is via the tissue factor pathway in which a non-proteolytic enzyme activator, tissue factor, complexes with a plasma protein, factor VII. Factor VII is the zymogen of a serine protease, factor VIIa. While factor VII-tissue factor has coagulant activity, upon conversion to factor VIIa the activity increases about 120-fold. We now show that tissue factor markedly accelerates the conversion of factor VII to factor VIIa. Thus, this essential coagulation cofactor is clearly bifunctional.
D000818:Animals; D002417:Cattle; D004530:Egg Yolk; D004789:Enzyme Activation; D005167:Factor VII / Q000378:metabolism*; D007700:Kinetics; D010713:Phosphatidylcholines / Q000494:pharmacology; D010718:Phosphatidylserines / Q000494:pharmacology; D013925:Thromboplastin / Q000502:physiology*
D010713:Phosphatidylcholines; D010718:Phosphatidylserines; D005167:Factor VII; D013925:Thromboplastin