Hementin is an anticoagulant protease from the salivary glands of the giant Amazon leech (Haementeria ghilianii). Hementin dissolves a type of platelet rich blood clot which cannot be dissolved by other well used drugs like streptokinase and urokinase.

Hementin is a calcium-dependent protease with a molecular weight of 80-120 kDa. It is capable of disrupting the function of fibrinogen, a glycoprotein responsible for blood clotting, by cleaving three peptide bonds in its structure. Fibrinogen acts as a substrate for thrombin, which converts the protein into its functional form, fibrin. Cleavage of fibrinogen in its native conformation at Asn102-Asn103, Lys130-Gln131, and Pro76-Asn77 yield three sets of products.[1] Hementin may also cause platelet deaggregation, although such effects are not as emphasized as its proteolytic capabilities.[2] Because of its anticoagulant effects, Hementin can be described as a hemostatic regulator.


  1. ^ Budzynski, A. Z. (February 1991). "Interaction of hementin with fibrinogen and fibrin". Blood Coagulation & Fibrinolysis. 2 (1): 149–152. doi:10.1097/00001721-199102000-00022. ISSN 0957-5235. PMID 1772982.
  2. ^ Zavalova, L. L.; Basanova, A. V.; Baskova, I. P. (2002). "Fibrinogen–Fibrin System Regulators from Bloodsuckers". Biochemistry (Moscow). 67 (1): 135–142. doi:10.1023/A:1013916601281.

External linksEdit

  • Malinconico, SM; Katz, JB; Budzynski, AZ (January 1984). "Hementin: anticoagulant protease from the salivary gland of the leech Haementeria ghilianii". The Journal of Laboratory and Clinical Medicine. 103 (1): 44–58. PMID 6361187.