Discussion Starter · #1 ·
Heparin binds to Antithrombin III (ATIII) and dramatically accelerates its enzymatic activity. As a serine protease inhibitor, ATIII-heparin can inactivate the serine proteases of the intrinsic pathway, XIIIa, XIa, IXa, and Xa - but what is its primary anti-coagulative activity?
- ATIII stimulates the release of plasminogen activators from tissues
- Activated ATIII dissolves the cross-linking of fibrin by proteolysis
- ATIII catalyses the binding of thrombin to thrombomodulin, allowing Protein C to be activated
- One molecule of ATIII inactivates one molecule of thrombin; heparin is catalytic
- Plasmin is cleaved from plasminogen by ATIII