Biochemical characterization of a thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus
Comparative study published in 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.
Resumen
Dipetalogastin, a thrombin inhibitor from Dipetalogaster maximus, is a tight-binding inhibitor with dissociation constant of 125 fM and specific thrombin inhibitory activity comparable to recombinant hirudin.
Por qué esto importa para la hirudoterapia
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. The relevance to ASH's domain is indirect: although dipetalogastin is biochemically analogous to leech-derived hirudin as a potent, tight-binding thrombin inhibitor from a blood-feeding invertebrate, 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.
Citación
Biochemical characterization of a thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus.
Lange U et al. · Haemostasis, 1999
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: June 18, 2026