New anticoagulant protein from medicinal leech
Discovery study published in Biochem Biophys Res Commun (2024)
Abstract
The saliva of the medicinal leech contains various anticoagulants. Some of them, such as hirudin, are well known. However, it is reasonable to believe that not all anticoagulant proteins from medicinal leech saliva have been identified. We previously performed a comprehensive study of the transcriptome, genome, and proteome of leech salivary gland cells, which led to the discovery of several previously unknown hypothetical proteins that may have anticoagulant properties. Subsequently, we obtained a series of recombinant proteins and investigated their impact on coagulation in in vitro assays. We identified a previously undescribed protein that exhibited a high ability to suppress coagulation. The His-tagged recombinant protein was expressed in Escherichia coli and purified using metal chelate chromatography. To determine its activity, commonly used coagulation methods were used: activated partial thromboplastin time, prothrombin time, and thrombin inhibition clotting assay. Clotting and chromogenic assays for factor Xa inhibition were performed to evaluate anti-Xa activity. We used recombinant hirudin as a control anticoagulant protein in all experiments. The new protein showed significantly greater inhibition of coagulation than hirudin at the same molar concentrations in the activated partial thrombin time assay. However, hirudin demonstrated better results in the direct thrombin inhibition test, although the tested protein also exhibited the ability to inhibit thrombin. The chromogenic analysis of factor Xa inhibition revealed no activity, whereas the clotting test for factor Xa showed the opposite result. Thus, a new powerful anticoagulant protein has been discovered in the medicinal leech. This protein is homologous to antistatin, with 28 % identical amino acid residues. The recombinant protein was expressed in E. coli. This protein is capable of directly inhibiting thrombin, and based on indirect evidence, other proteases of the blood coagulation cascade have been identified.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Newly discovered medicinal leech anticoagulant protein homologous to antistasin (28% identity) with stronger aPTT inhibition than hirudin at equimolar concentrations; expressed in E. coli for evaluation.
Por qué esto importa para la hirudoterapia
Este estudio reporta el descubrimiento y la caracterización in vitro de una proteína anticoagulante previamente no descrita de la saliva de la sanguijuela medicinal, identificada mediante análisis previos de transcriptoma, genoma y proteoma de células de las glándulas salivales de la sanguijuela. La proteína recombinante, expresada en E. coli y homóloga a la antistatina (28% de identidad aminoacídica), mostró una inhibición de la coagulación significativamente mayor que la hirudina recombinante a concentraciones equimolares en el ensayo de tiempo de tromboplastina parcial activada, exhibió cierta inhibición directa de la trombina (aunque menos potente que la hirudina), y arrojó resultados mixtos en los ensayos del factor Xa. Para el ámbito de ASH, esto es altamente relevante, ya que amplía el repertorio conocido de anticoagulantes secretados por la sanguijuela más allá de la hirudina, lo que sugiere un potencial farmacológico adicional dentro del secretoma de la sanguijuela. Sin embargo, todos los hallazgos provienen únicamente de ensayos de coagulación in vitro; no se presentan datos in vivo, en animales ni clínicos, y la relevancia terapéutica de la proteína sigue siendo completamente no establecida.
Citación
New anticoagulant protein from medicinal leech.
Manuvera VA et al. · Biochemical and biophysical research communications, 2024
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026