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
This study reports the isolation and molecular characterization of two novel antimicrobial peptides — theromacin (a 75-amino acid cationic peptide with 10 cysteine residues) and theromyzin (an 86-amino acid linear anionic peptide) — from the coelomic liquid of the leech Theromyzon tessulatum. Both peptides showed activity against Gram-positive bacteria, and their mRNA levels increased after blood meal ingestion and bacterial challenge, with expression localized to large fat cells and peptide release into coelomic fluid after challenge. For ASH's domain, this is relevant as it characterizes the innate immune defense system of leeches, which may inform understanding of how leeches manage microbial colonization. However, this is a basic science study with no data on therapeutic applications, human pathogens relevant to leech therapy, or clinical implications.
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
Contexto clínico relacionado
Explore cómo esta investigación se conecta con la práctica clínica
Añadido a la biblioteca ASH: May 26, 2026 · Última actualización del sitio: June 18, 2026