Molecular characterization of two novel antibacterial peptides inducible upon bacterial challenge in an annelid, the leech Theromyzon tessulatum
Biochemistry article published in Journal of Biological Chemistry (2004)
Abstract
Two novel antimicrobial peptides named theromacin and theromyzin were isolated and characterized from the coelomic liquid of the leech Theromyzon tessulatum. Theromacin is a 75-amino acid cationic peptide containing 10 cysteine residues arranged in a disulfide array showing no similarities with other known antimicrobial peptides. Theromyzin is an 86-amino acid linear peptide and constitutes the first anionic antimicrobial peptide observed in invertebrates. Both peptides exhibit activity directed against Gram-positive bacteria. Theromacin and theromyzin cDNAs code precursor molecules containing a putative signal sequence directly followed by the mature peptide. The enhancement of theromacin and theromyzin mRNA levels has been observed after blood meal ingestion and upon bacterial challenge. In situ hybridization revealed that both genes are expressed in large fat cells in contact with coelomic cavities. Gene products were immunodetected in large fat cells, in intestinal epithelia, and at the epidermis level. In addition, a rapid release of the peptides into the coelomic liquid was observed after bacterial challenge. The presence of antimicrobial peptide genes in leeches and their expression in a specific tissue functionally resembling the insect fat body provide evidence for the first time of an antibacterial response in a lophotrochozoan comparable to that of holometabola insects.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Resumen
Isolation and characterization of theromacin (75-aa cationic cysteine-rich peptide) and theromyzin (86-aa anionic peptide; first anionic AMP in invertebrates) from leech Theromyzon tessulatum coelomic fluid, with bacterial-challenge induction.
Por qué esto importa para la hirudoterapia
Este estudio reporta el aislamiento y caracterización molecular de dos nuevos péptidos antimicrobianos —theromacin (un péptido catiónico de 75 aminoácidos con 10 residuos de cisteína) y theromyzin (un péptido aniónico lineal de 86 aminoácidos)— del líquido celómico de la sanguijuela Theromyzon tessulatum. Ambos péptidos mostraron actividad contra bacterias grampositivas, y sus niveles de ARNm aumentaron tras la ingesta sanguínea y el desafío bacteriano, con expresión localizada en grandes células adiposas y liberación del péptido al fluido celómico tras el desafío. Para el ámbito de la ASH, esto es relevante, ya que caracteriza el sistema de defensa inmune innata de las sanguijuelas, lo que puede contribuir a la comprensión de cómo las sanguijuelas gestionan la colonización microbiana. No obstante, se trata de un estudio de ciencia básica sin datos sobre aplicaciones terapéuticas, patógenos humanos relevantes para la terapia con sanguijuelas, o implicaciones clínicas.
Citación
Molecular characterization of two novel antibacterial peptides inducible upon bacterial challenge in an annelid, the leech Theromyzon tessulatum.
Tasiemski A, Vandenbulcke F, Mitta G, Lemoine J, Lefebvre C, Sautière PE, Salzet M · The Journal of biological chemistry, 2004
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Añadido a la biblioteca ASH: May 26, 2026 · Última actualización del sitio: 18 de junio de 2026