Thrombin inhibitor activated by the glycosaminoglycans, heparin or dermatan sulfate. In the presence of the latter, HC-II becomes the predominant thrombin inhibitor in place of antithrombin III (AT-III). Also inhibits chymotrypsin, but in a glycosaminoglycan-independent manner. Peptides at the N-terminal of HC-II have chemotactic activity for both monocytes and neutrophils.
Expressed predominantly in liver. Also present in plasma.
Involvement in disease
Thrombophilia due to heparin cofactor 2 deficiency
Belongs to the serpin family.
The N-terminal acidic repeat region mediates, in part, the glycosaminoglycan-accelerated thrombin inhibition.
Phosphorylation sites are present in the extracellular medium.