American Society of Hirudotherapy

Purification and characterization of recombinant antistasin: a leech-derived inhibitor of coagulation factor Xa

Research article published in Arch Biochem Biophys (1991)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsSalivary PharmacologyNutt EM et al. · Arch Biochem Biophys, 1991

Abstract

Antistasin (ATS) is a selective, tight-binding inhibitor of blood coagulation Factor Xa originally isolated from the salivary glands of the Mexican leech Haementeria officinalis. In order to provide sufficient quantities of ATS to further investigate the role of Factor Xa in blood coagulation, a recombinant version of ATS has been produced in an insect baculovirus host-vector system. In this study, we describe the purification and in vitro and in vivo characterization of a single recombinant antistasin (rATS) isoform. The purified protein constitutes a minor isoform relative to the more abundant ATS isoforms present in leech salivary gland extracts. In vitro, rATS inhibits purified human Factor Xa stoichiometrically, prolongs plasma-based clotting assays at nanomolar concentrations, and like native ATS, is cleaved at a single position by Factor Xa during the course of inhibition. An initial evaluation of the in vivo efficacy of rATS was addressed utilizing a rhesus monkey model of mild disseminated intravascular coagulation. rATS was shown to fully suppress thromboplastin-induced fibrinopeptide A generation in a dose-dependent fashion. The availability of rATS should provide a valuable tool for the critical evaluation of the specific role played by Factor Xa in coagulation.

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

Publication typeJournal Article
Indexed MeSH termsAmino Acid SequenceAnimalsBaculoviridaeBlood CoagulationChromatography, High Pressure LiquidChromatography, Ion ExchangeElectrophoresis, Polyacrylamide GelFactor Xa InhibitorsFibrinopeptide AInvertebrate HormonesIsomerismLeeches

Summary

Antistasin (ATS) is a selective, tight-binding inhibitor of blood coagulation Factor Xa originally isolated from the salivary glands of the Mexican leech Haementeria officinalis.

Why This Matters for Hirudotherapy

This study describes the purification and in vitro/in vivo characterization of recombinant antistasin (rATS), a selective Factor Xa inhibitor originally isolated from the salivary glands of the Mexican leech Haementeria officinalis, produced in a baculovirus expression system. In vitro, rATS stoichiometrically inhibited purified human Factor Xa, prolonged plasma clotting assays at nanomolar concentrations, and—like native antistasin—was cleaved at a single position by Factor Xa during inhibition. In vivo, rATS fully suppressed thromboplastin-induced fibrinopeptide A generation in a dose-dependent manner in a rhesus monkey model of mild disseminated intravascular coagulation. This work is relevant to ASH's domain as it advances understanding of a distinct leech-derived anticoagulant protein beyond hirudin. However, the data are preclinical, the study evaluated only a single minor isoform, and no human clinical data are provided.

Citation

Purification and characterization of recombinant antistasin: a leech-derived inhibitor of coagulation factor Xa.

Nutt EM et al. · Arch Biochem Biophys, 1991

DOI

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