American Society of Hirudotherapy

Biochemical characterization of a thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus

In vitro biochemical characterization study published in Haemostasis (1999)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Salivary PharmacologyDrug DevelopmentLange U et al. · Haemostasis, 1999

Abstract

From the bloodsucking bug Dipetalogaster maximus, a protein with anticoagulant activity was isolated and biochemically characterized. The isolated protein, named dipetalogastin, possesses an average molecular mass of 11.8 kD. Its N-terminal sequence shows homology to rhodniin, a thrombin inhibitor isolated from the bug Rhodnius prolixus. The in vitro anticoagulant activity of dipetalogastin occurs via the inhibition of thrombin. The anticoagulant and thrombin inhibitory potency of dipetalogastin is comparable to that of recombinant hirudin. Its specific thrombin inhibitory activity is 9,300 antithrombin units/mg protein. Dipetalogastin forms only 1:1 molar complexes with thrombin. It is a tight-binding inhibitor of thrombin possessing a dissociation constant of 125 fM. It does not inhibit factor Xa or alpha-chymotrypsin and only weakly inhibits trypsin.

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

Publication typeComparative StudyJournal Article
Indexed MeSH termsAmino Acid SequenceAnimalsAnticoagulantsBlood Coagulation TestsChromatography, AffinityChromatography, GelChromatography, High Pressure LiquidEndopeptidasesEnzyme InhibitorsFactor XFibrinogenHirudinsInsect ProteinsMaleMolecular Sequence DataMolecular WeightPartial Thromboplastin TimeProtein BindingStomachThrombinThrombin TimeTriatominaeTrypsinTrypsin Inhibitors

Summary

Dipetalogastin, an anticoagulant protein isolated from the bloodsucking bug Dipetalogaster maximus, inhibits thrombin with potency comparable to recombinant hirudin, forms 1:1 complexes with thrombin, and is a tight-binding inhibitor with a dissociation constant of 125 fM.

Context

This study describes the isolation and biochemical characterization of dipetalogastin, an 11.8 kDa thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus. Dipetalogastin forms a 1:1 complex with thrombin, exhibits a dissociation constant of 125 fM, and has specific thrombin inhibitory activity of 9,300 antithrombin units/mg, which the authors describe as comparable to recombinant hirudin. Its N-terminal sequence shows homology to rhodniin, another insect-derived thrombin inhibitor. Dipetalogastin is biochemically analogous to leech-derived hirudin as a potent, tight-binding thrombin inhibitor from a blood-feeding invertebrate, but it originates from a heteropteran insect, not a leech. No leeches or leech-derived molecules were studied; the hirudin comparison serves solely as a benchmark for inhibitor potency.

Citation

Reference (Vancouver style)

Lange U, Keilholz W, Schaub GA, Landmann H, Markwardt F, Nowak G. Biochemical characterization of a thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus. Haemostasis. 1999;29(4):204-211. doi:10.1159/000022503. PMID: 10702701

Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.

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