AR-H067637 is a rapid-binding, reversible and potent (inhibition constant K(i) = 2-4 nM), competitive inhibitor of thrombin, as well as of thrombin bound to fibrin (clot-bound thrombin) or to thrombomodulin. The total amount of free thrombin generated in
Hirudin (54-65; non-sulfated) is a desulfated peptide fragment of hirudin, an anticoagulant produced byH. medicinalis.1It inhibits fibrinclot formation induced by isolated bovine thrombin with an IC50value of 3.7 μM.2 1.Niehrs, C., Huttner, W.B., Carvallo, D., et al.Conversion of recombinant hirudin to the natural form by in vitro tyrosine sulfation. Differential substrate specificities of leech and bovine tyrosylprotein sulfotransferasesJ. Biol. Chem.265(16)9314-9318(1990) 2.Payne, M.H., Krstenansky, J.L., Yates, M.T., et al.Positional effects of sulfation in hirudin and hirudin PA related anticoagulant peptidesJ. Med. Chem.34(3)1184-1187(1991)