Activation of heparin cofactor II by heparin and dermatan sulfate.
Heparin cofactor II is a glycoprotein present in human plasma at a concentration of approximately 1.2 microM. It inhibits thrombin by forming a stable, 1:1 complex with the protease. The rate of complex formation is increased approximately 1,000-fold by heparin or dermatan sulfate. Heparin cofactor II appears to be the only thrombin inhibitor in plasma that can be activated by dermatan sulfate. Platelet factor 4 abolishes the activation of heparin cofactor II by dermatan sulfate, but plasma histidine-rich glycoprotein does not. Heparin cofactor II is activated by dermatan sulfate oligosaccharides that are at least 12-14 sugar residues in length and contain a high-affinity binding site for the inhibitor protein.
D002807:Chondroitin / Q000031:analogs & derivatives*; D003871:Dermatan Sulfate / Q000378:metabolism / Q000494:pharmacology*; D006023:Glycoproteins / Q000378:metabolism* / Q000494:pharmacology; D006493:Heparin / Q000494:pharmacology*; D006494:Heparin Antagonists / Q000494:pharmacology; D015844:Heparin Cofactor II; D006639:Histidine / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008970:Molecular Weight; D010978:Platelet Factor 4 / Q000494:pharmacology
D006023:Glycoproteins; D006494:Heparin Antagonists; D003871:Dermatan Sulfate; D010978:Platelet Factor 4; D006639:Histidine; D015844:Heparin Cofactor II; D006493:Heparin; D002807:Chondroitin