title: Novel antimicrobial peptides derived from flatfish genes.
abstract: We report on the identification of active novel antimicrobials determined by screening both the genomic information and the mRNA transcripts from a number of different flatfish for sequences encoding antimicrobial peptides, predicting the sequences of active peptides from the genetic information, producing the predicted peptides chemically, and testing them for their activities. We amplified 35 sequences from various species of flatfish using primers whose sequences are based on conserved flanking regions of a known antimicrobial peptide from winter flounder, pleurocidin. We analyzed the sequences of the amplified products and predicted which sequences were likely to encode functional antimicrobial peptides on the basis of charge, hydrophobicity, relation to flanking sequences, and similarity to known active peptides. Twenty peptides were then produced synthetically and tested for their activities against gram-positive and gram-negative bacteria and the yeast Candida albicans. The most active peptide (with the carboxy-terminus amidated sequence GWRTLLKKAEVKTVGKLALKHYL, derived from American plaice) showed inhibitory activity over a concentration range of 1 to 8 micro g/ml against a test panel of pathogens, including the intrinsically antibiotic-resistant organism Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and C. albicans. The methods described here will be useful for the identification of novel peptides with good antimicrobial activities.
authors.affiliation: Institute for Marine Biosciences, National Research Council of Canada, Halifax NS B3H 3Z1, Canada.
authors.forename: Aleksander
authors.initials: A
authors.lastname: Patrzykat
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Gallant
authors.forename: Jung-Kil
authors.initials: JK
authors.lastname: Seo
authors.forename: Jennifer
authors.initials: J
authors.lastname: Pytyck
authors.forename: Susan E
authors.initials: SE
authors.lastname: Douglas
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D002412:Cations / Q000737:chemistry; D005412:Flatfishes / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D002412:Cations; D010455:Peptides