American Society of Hirudotherapy

Bdellastasin, a serine protease inhibitor of the antistasin family from the medical leech

Biochemistry study published in European Journal of Biochemistry (1998)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportGenomics & ProteomicsSalivary PharmacologyMoser M et al. · European journal of biochemistry, 1998

Abstract

We have reported earlier the isolation and amino acid composition of bdellin A from medical leech, and characterised it as an inhibitor of trypsin, plasmin and acrosin [Fritz, H., Gebhardt, M., Meister, R. & Fink, E. (1971) in Proceedings of the international research conference on proteinase inhibitors (Fritz, H. & Tschesche, H., eds) pp. 271-280, Walter de Gruyter, Berlin]. In the present study, one of several chromatographic forms of this inhibitor was isolated from a semi-pure preparation. Elucidation of its amino acid sequence revealed that bdellin A is a member of the antistasin family. Therefore, it was renamed bdellastasin to avoid confusion with bdellin B, which is another trypsin-plasmin inhibitor from the medical leech, but of the Kazal type. Furthermore, a synthetic gene of bdellastasin was constructed, and the protein expressed in Saccharomyces cerevisiae with yields of 29 mg/l. The recombinant bdellastasin was purified by hydrophobic interaction and anion-exchange chromatography. Comparison by mass spectroscopy, far-ultraviolet circular dichroism studies, sequence determination, and inhibition characteristics demonstrated the identity of recombinant and native bdellastasin. The Ki values of bdellastasin for inhibition of bovine trypsin and human plasmin are in the nanomolar range; no inhibition was detected for factor Xa, thrombin, tissue kallikrein, plasma kallikrein and chymotrypsin. Circular dichroism analyses indicated that bdellastasin is devoid of secondary-structural elements.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAnimalsBase SequenceCattleCircular DichroismCloning, MolecularDNA PrimersGene ExpressionGenetic VectorsHumansInvertebrate HormonesLeechesOrganic Chemicals

Summary

First isolation and characterization of bdellastasin from Hirudo medicinalis — antistasin-family inhibitor expressed in yeast for structural and functional studies.

Why This Matters for Hirudotherapy

This study isolated a chromatographic form of bdellin A from the medical leech, determined its amino acid sequence, and renamed it bdellastasin upon confirming membership in the antistasin family. A synthetic bdellastasin gene was expressed in Saccharomyces cerevisiae at 29 mg/L, and the recombinant protein was shown to be identical to native bdellastasin by mass spectrometry, circular dichroism, sequencing, and inhibition profiling. Bdellastasin inhibits bovine trypsin and human plasmin with nanomolar Ki values but shows no inhibition of factor Xa, thrombin, tissue or plasma kallikrein, or chymotrypsin, and circular dichroism indicates an absence of regular secondary structure. This is relevant to ASH as a molecular characterization of a medicinal-leech secretome component with established recombinant expression. The study is limited to biochemical characterization; no in-vivo or clinical data are reported.

Citation

Bdellastasin, a serine protease inhibitor of the antistasin family from the medical leech.

Moser M et al. · European journal of biochemistry, 1998

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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