heparin cofactor II precursor fragment [Homo sapiens], (C65H99N17O18), a peptide with the sequence H2N-Tyr-Glu-Ile-Thr-Thr-Ile-His-Asn-Leu-Phe-Arg-OH, MW=1406.58. Heparin cofactor II(HCII), a protein encoded by the SERPIND1 gene, is a coagulation factor that inhibits IIa, and is a cofactor for heparin and dermatan sulfate1. The product encoded by this gene is a serine proteinase inhibitor which rapidly inhibits thrombin in the presence of dermatan sulfate or heparin. The gene contains five exons and four introns. This protein shares homology with antithrombin III and other members of the alpha 1-antitrypsin superfamily. Mutations in this gene are associated with heparin cofactor II deficiency2. Heparin Cofactor II deficiency can lead to increased thrombin generation and a hypercoagulable state.
References:
1. Pizzo SV (1989). "Serpin receptor 1: a hepatic receptor that mediates the clearance of antithrombin III-proteinase complexes.". Am. J. Med. 87 (3B): 10S-14S.
2. Sutherland JS, Bhakta V, Filion ML, SheffieldWP (2006). "The transferable tail: fusion of the N-terminal acidic extension of heparin cofactor II to alpha1-proteinase inhibitor M358R specifically increases the rate of thrombin inhibition.". Biochemistry 45 (38): 11444-52.