Functional expression of a thrombin exosite I inhibitor triabin in Escherichia coli
Biochemistry study published in Biochimie (2023)
Abstract
Triabin, a lipocalin-like thrombin inhibitor from the saliva of the blood-sucking triatomine bug Triatoma pallidipennis, exhibits effective inhibition comparable to hirudin despite binding exclusively at exosite I. Interestingly, it was reported that higher triabin doses would not inhibit thrombin completely, which makes it a promising antithrombotic candidate agent with a larger therapeutic window. However, few structural and functional studies about triabin have been reported in the past three decades, mostly due to the lack of a reliable and practicable recombinant expression technology for this seemingly small protein. In this work, we have adopted the SUMO fusion technology for the expression of triabin in E. coli cells-with facile refolding and purification procedures-and the bioactive triabin was produced in ∼12 mg/L culture medium. Subsequently, the structure-function studies through extensive site-directed mutagenesis reveal that triabin's Phe-106 involved in the hydrophobic contacts plays a surprisingly important role in the thrombin inhibition, in contrast to the negatively charged residues Asp-135 or Glu-128 involved in the salt-bridge interaction. As such, this study complements our understanding of the interaction mechanism of natural thrombin inhibitors, which should facilitate the development of anticoagulant drugs with a novel mode of action against thrombin.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Recombinant expression and characterization of triabin (triatomine-bug thrombin-exosite-I inhibitor) — comparative reference to leech-derived exosite-I-targeting hirudin variants.
Por qué esto importa para la hirudoterapia
Este estudio desarrolló un sistema de expresión recombinante en fusión con SUMO en E. coli para la triabina, un inhibidor del exosito I de la trombina proveniente de la saliva del triatomino Triatoma pallidipennis, produciendo aproximadamente 12 mg/L de proteína bioactiva y utilizando mutagénesis dirigida para demostrar la importancia de la Phe-106 en la inhibición de la trombina. Se señala que la triabina exhibe una inhibición efectiva comparable a la de la hirudina, pese a un modo de unión diferente, lo que ofrece una ventana terapéutica potencialmente mayor. Para el dominio de la ASH, la relevancia es indirecta: el estudio se refiere a un inhibidor salival de un artrópodo hematófago no relacionado con sanguijuelas, no a sanguijuelas ni a la hirudoterapia, aunque la comparación con la hirudina y el enfoque en proteínas salivales antitrombóticas es conceptualmente adyacente. No se estudia ningún material derivado de sanguijuelas.
Citación
Functional expression of a thrombin exosite I inhibitor triabin in Escherichia coli.
Mo Z et al. · Biochimie, 2023
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026