Fibrino(geno)lytic properties of purified hementerin, a metalloproteinase from the leech Haementeria depressa
Biochemistry published in Thromb Haemost (1998)
Abstract
The fibrino(geno)lytic protein designated hementerin contained in crude extracts of the salivary complex of Haementeria depressa leeches was purified to apparent homogeneity by gel filtration, ion exchange chromatography and preparative SDS-PAGE. It is a single-chain 80 kDa, PhMeSO2F-resistant, calcium-dependent, metalloproteinase, which specifically degrades fibrin(ogen) through a plasminogen-independent pathway. The amino terminal sequence of 8 residues shows 80% similarity with hementin, another fibrino(geno)lytic protein purified from Haementeria ghilianii leeches. However, their activities differ somewhat in terms of kinetics and with regard to the structure of the fibrin(ogen) fragments they may produce. Cleavage by hementerin of fibrinogen Aalpha, gamma and Bbeta chains, in that order, produces 270 kDa to 67 kDa fragments which differ from those produced by plasmin. Hementerin was also able to degrade cross-linked fibrin although at a lower rate as compared to fibrinogen. In conclusion, hementerin is a plasminogen-independent fibrino(geno)lytic metalloproteinase that degrades fibrinogen faster than fibrin, prevents blood coagulation and destroys fibrin clots in vitro.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Hementerin (80 kDa, calcium-dependent metalloproteinase from Haementeria depressa) shares 80% N-terminal sequence similarity with hementin but exhibits distinct fibrinogen-cleavage kinetics. Degrades fibrinogen faster than fibrin, plasminogen-independent.
Por qué esto importa para la hirudoterapia
This study purified and characterized hementerin, a fibrino(geno)lytic metalloproteinase from the salivary complex of the leech Haementeria depressa, determining it to be an 80 kDa single-chain, calcium-dependent enzyme that degrades fibrin(ogen) via a plasminogen-independent pathway. It is relevant to ASH's domain as a characterization of another leech-secretome anticoagulant enzyme, showing 80% amino-terminal sequence similarity to hementin from Haementeria ghilianii while differing in kinetics and fragment profiles. The abstract demonstrates that hementerin degrades fibrinogen Aalpha, gamma, and Bbeta chains (producing 270–67 kDa fragments), prevents coagulation, and destroys fibrin clots in vitro. However, this is an in-vitro biochemical purification and characterization study with no in-vivo, clinical, or therapeutic data; its relevance to hirudotherapy is limited to expanding knowledge of leech secretome enzymatic diversity.
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Añadido a la biblioteca ASH: May 26, 2026 · Última actualización del sitio: June 18, 2026