title: Isolation and characterization of pleurocidin, an antimicrobial peptide in the skin secretions of winter flounder.
abstract: Antimicrobial peptides are found in both myeloid cells and mucosal tissues of many vertebrates and invertebrates. These peptides are predicted to operate as a first-line host defense mechanism exerting broad-spectrum activity against pathogenic bacteria, fungi, parasites, and enveloped viruses. We report the characterization of a novel 25-residue linear antimicrobial peptide found in the skin mucous secretions of the winter flounder (Pleuronectes americanus). This peptide was purified through multiple chromatographic methods to obtain a single peak by reversed-phase high performance liquid chromatography. This purified peptide, which we named pleurocidin, exhibited antimicrobial activity against Escherichia coli in a bacterial cell lysis plate assay. Mass spectrometry and amino acid sequence analysis indicated that it is 25 amino acids in length. Pleurocidin is predicted to assume an amphipathic alpha-helical conformation similar to many other linear antimicrobial peptides. There is a high degree of homology between pleurocidin and two antimicrobial peptides, ceratotoxin from the Mediterranean fruit fly and dermaseptin from the skin of a hylid frog. The minimal inhibitory concentration and minimal bactericidal concentration of pleurocidin were determined against 11 different Gram-negative and Gram-positive bacteria. Immunohistochemistry locates pleurocidin in the epithelial mucous cells of flounder skin. Pleurocidin represents a novel antimicrobial peptide found in fish and may play a role in innate host defense.
authors.affiliation: Department of Anatomy, Cell Biology and Injury Sciences, UMDNJ-New Jersey Medical School and Graduate School of Biomedical Sciences, Newark, New Jersey 07103, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Cole
authors.forename: P
authors.initials: P
authors.lastname: Weis
authors.forename: G
authors.initials: G
authors.lastname: Diamond
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification; D023181:Antimicrobial Cationic Peptides; D001419:Bacteria / Q000187:drug effects* / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects; D029941:Fish Proteins; D005432:Flounder; D007150:Immunohistochemistry; D019476:Insect Proteins / Q000737:chemistry; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D012867:Skin / Q000166:cytology / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D019476:Insect Proteins; D010455:Peptides; D011506:Proteins; C082689:ceratotoxin A protein, Ceratitis capitata; C105851:pleurocidin; C070905:dermaseptin; C082690:ceratotoxin B protein, Ceratitis capitata