title: Ixodidin, a novel antimicrobial peptide from the hemocytes of the cattle tick Boophilus microplus with inhibitory activity against serine proteinases.
abstract: The presence of an effective immune response in the hemocoel of arthropods is essential for survival as it prevents the invasion of pathogens throughout the animal body. Antimicrobial peptides (AMPs) play an important role in this response by rapidly killing invading microorganisms. In this study, a novel cysteine-rich AMP has been isolated and characterized from the hemocytes of the cattle tick, Boophilus microplus. In addition to growth inhibition of Escherichia coli and Micrococcus luteus, the newly described AMP, designated ixodidin (derived from the Family Ixodidae), was found to exert proteolytic inhibitory activity against two exogenous serine proteinases, elastase and chymotrypsin. This is the first report of a molecule of an arachnid that has been shown to inhibit bacterial growth and proteinase activity.
authors.affiliation: Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, Zip Code 05508-900 São Paulo, SP, Brazil.
authors.forename: Andréa C
authors.initials: AC
authors.lastname: Fogaça
authors.forename: Igor C
authors.initials: IC
authors.lastname: Almeida
authors.forename: Marcos N
authors.initials: MN
authors.lastname: Eberlin
authors.forename: Aparecida S
authors.initials: AS
authors.lastname: Tanaka
authors.forename: Philippe
authors.initials: P
authors.lastname: Bulet
authors.forename: Sirlei
authors.initials: S
authors.lastname: Daffre
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002417:Cattle; D006434:Hemocytes / Q000737:chemistry*; D026863:Ixodidae / Q000737:chemistry* / Q000166:cytology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; C512324:Ixodidin, Boophilus microplus; D010455:Peptides; D015842:Serine Proteinase Inhibitors