title: Phylloxin, a novel peptide antibiotic of the dermaseptin family of antimicrobial/opioid peptide precursors.
abstract: A novel family of peptide precursors that have very similar N-terminal preprosequences followed by markedly different C-terminal domains has been identified in the skin of hylid frogs belonging to the genus Phyllomedusinae. Biologically active peptides derived from the variable domains include the dermaseptins, 28-34-residue peptides that have a broad-spectrum microbicidal activity, and dermorphin and the deltorphins, D-amino acid containing heptapeptides that are very potent agonists for the micro-opioid and delta-opioid receptors, respectively. This report describes the isolation, synthesis and cloning of phylloxin, a prototypical member of a novel family of antimicrobial peptides derived from the processing of a dermaseptin/dermorphin-like precursor. The structure of phylloxin (GWMSKIASGIGTFLSGIQQ amide) shows no homology to the dermaseptins, but bears some resemblance to the levitide-precursor fragment and the xenopsin-precursor fragment, two antimicrobial peptides isolated from the skin of an evolutionarily distant frog species, Xenopus laevis. Circular dichroism spectra of phylloxin in low polarity medium, which mimics the lipophilicity of the membrane of target microorganisms, indicated 60-70% alpha-helical conformation, and predictions of secondary structure suggested that the peptide can be configured as an amphipathic helix spanning residues 1-19. Phylloxin is an addition to the structurally and functionally diverse peptide families encoded by the rapidly evolving C-terminal domains of the dermorphin/dermaseptin group of precursors.
authors.affiliation: Laboratoire de Bioactivation des Peptides, Institut Jacques Monod, Paris, France.
authors.forename: T N
authors.initials: TN
authors.lastname: Pierre
authors.forename: A A
authors.initials: AA
authors.lastname: Seon
authors.forename: M
authors.initials: M
authors.lastname: Amiche
authors.forename: P
authors.initials: P
authors.lastname: Nicolas
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001001:Anura; D001483:Base Sequence; D003001:Cloning, Molecular; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D018847:Opioid Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D012867:Skin / Q000737:chemistry; D014020:Tissue Extracts / Q000737:chemistry
chemical_list: D029845:Amphibian Proteins; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D018847:Opioid Peptides; D010455:Peptides; D011498:Protein Precursors; D014020:Tissue Extracts; C404703:phylloxin; C070905:dermaseptin