Expression analysis and biological activity of moronecidin from rock bream, Oplegnathus fasciatus

• Published in: Fish & shellfish immunology Vol. 40; no. 2; pp. 345 - 353
• Main Authors: Bae, Jin-Sol, Shim, Sang Hee, Hwang, Seong Don, Park, Myoung-Ae, Jee, Bo-Young, An, Cheul-Min, Kim, Young-Ok, Kim, Ju-Won, Park, Chan-Il
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.10.2014
• Subjects: Amino Acid Sequence; Animals; Antimicrobial activity; Antimicrobial Cationic Peptides - chemistry; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - metabolism; Antimicrobial peptides; Base Sequence; Cytotoxic activity; DNA Virus Infections - immunology; DNA Virus Infections - veterinary; DNA Virus Infections - virology; Edwardsiella tarda; Edwardsiella tarda - physiology; Enterobacteriaceae Infections - immunology; Enterobacteriaceae Infections - microbiology; Enterobacteriaceae Infections - veterinary; Fish Diseases - immunology; Fish Diseases - microbiology; Fish Diseases - virology; Fish Proteins - chemistry; Fish Proteins - genetics; Fish Proteins - metabolism; Gene Expression Regulation; Immunity, Innate; Iridoviridae - physiology; Iridovirus; Molecular Sequence Data; Moronecidin; Oplegnathus fasciatus; Perciformes - genetics; Phylogeny; Real-Time Polymerase Chain Reaction - veterinary; Rock bream; Sequence Alignment - veterinary; Streptococcal Infections - immunology; Streptococcal Infections - microbiology; Streptococcal Infections - veterinary; Streptococcus - physiology; Streptococcus iniae; Rock bream; Antimicrobial activity; Moronecidin; Antimicrobial peptides; Cytotoxic activity
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2014.07.023

The piscidin-family, one of antimicrobial peptides (AMPs) mainly distributed in fish, is crucial effectors of fish innate immune response. Piscidin-family typically has broad-spectrum antimicrobial activity and the ability to modulate the immune response. In this study, we identified moronecidin (Rbmoro) included in piscidin-family from rock bream and investigated its gene expression using quantitative real-time PCR and biological activity (including antimicrobial and cytotoxic activity). The coding region of Rbmoro was 204 bp encoding 67 amino acid residues. Tertiary structure prediction of Rbmoro showed an amphipathic α-helical structure. Rbmoro gene was widely expressed in different tissues of healthy fish. Additionally, Rbmoro gene expression was induced in all tested tissues after infection with Edwardsiella tarda, Streptococcus iniae and red seabream iridovirus. We synthesized mature peptide of Rbmoro based on amino acid sequence of its AMP 12 domain, and the synthetic peptide appeared broad-spectrum antimicrobial activity to various bacteria. However, the synthetic peptide has weak haemolytic activity against fish erythrocytes. These results suggest that Rbmoro might play an important role in innate immune response of rock bream. •The mature peptide of Rbmoro has an amphipathic α-helix conformation.•Rbmoro gene was widely expressed in different tissues of healthy fish.•Gene expression of Rbmoro was increased after pathogens infection.•Rbmoro has antimicrobial activity against various bacteria.•Rbmoro has weak haemolytic activity against fish erythrocytes.