What is the major anticoagulant action of heparin?
The major anticoagulant action of heparin is mediated by the heparin/AT interaction. The mechanism of this interaction was demonstrated in the 1970s. It binds to positively charged residues on AT, producing a conformational change at the AT arginine reactive center that converts AT from a slow to a rapid inhibitor of serine proteases. The arginine reactive center on AT binds covalently to the active center serine of thrombin and other coagulation enzymes, thereby irreversibly inhibiting their procoagulant activity.