The complete amino acid sequence of a hirudin variant from the leech Hirudinaria manillensis
Comparative study published in J Protein Chem (1993)
Abstract
Unlike the European leech Hirudo medicinalis, the Asian jawed leech Hirudinaria manillensis is specialized for feeding on mammalian blood. In the salivary glands of both these leeches, there is a potent inhibitor of thrombin, called hirudin, which acts as an anticoagulant. We have reported previously the isolation and purification of a variant of hirudin, called bufrudin, from the head portions of Hirudinaria. In the present study, the complete amino acid sequence of bufrudin was determined by automated Edman degradation of peptide fragments generated after cleavage of protein with trypsin or thermolysin. Comparison of the primary structure of bufrudin, with hirudin HV1, show about 70% sequence identity with deletion of two amino acids, but the key amino acids at the C-terminus, involved in the inhibition of thrombin, are conserved. However, similar sequence comparison of bufrudin with hirullin P18, a hirudin variant isolated from the same leech species but from whole leech, instead of heads, reveals even less sequence identity of about 60%. From the amino acid sequence, it is suggested that the conformation of the C-terminal portion of bufrudin may be significantly different from hirullin P18, but similar to hirudin HV1, upon its interaction with thrombin. These results indicate that, as with Hirudo leech, various isoforms of hirudin also exist in Hirudinaria leech, with a significant change occurring in the structure of the molecule during the evolution of leeches.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Complete amino acid sequence of bufrudin, a hirudin variant from Hirudinaria manillensis, shows 70% sequence identity with hirudin HV1 with conserved C-terminal thrombin-inhibitory residues.
Por qué esto importa para la hirudoterapia
Este estudio determinó la secuencia aminoacídica completa de la bufrudina, una variante de hirudina aislada de las porciones cefálicas de la sanguijuela asiática Hirudinaria manillensis, mediante degradación de Edman de fragmentos peptídicos. La bufrudina muestra ~70 % de identidad de secuencia con la hirudina HV1 (de Hirudo medicinalis) con dos residuos delecionados, pero conserva aminoácidos clave conservados del extremo C-terminal involucrados en la inhibición de la trombina; la comparación con la hirulina P18 (de Hirudinaria entera) mostró solo ~60 % de identidad y una conformación del extremo C-terminal potencialmente diferente. Estos hallazgos sugieren que existen múltiples isoformas de hirudina dentro de Hirudinaria, lo que refleja una diversificación estructural evolutiva. El estudio es relevante para el dominio de la ASH como caracterización molecular de un componente del secretoma de sanguijuela con actividad antitrombínica. La advertencia honesta es que se trata de un estudio a nivel de química proteica/taxonomía sin datos funcionales, in vivo, animales ni clínicos presentados; el resumen no reporta ensayos de actividad inhibitoria ni afirmaciones terapéuticas para la bufrudina.
Citación
The complete amino acid sequence of a hirudin variant from the leech Hirudinaria manillensis.
Electricwala A et al. · J Protein Chem, 1993
Contexto clínico relacionado
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Añadido a la biblioteca ASH: May 27, 2026 · Última actualización del sitio: 18 de junio de 2026