title: Isolation from an ant Myrmecia gulosa of two inducible O-glycosylated proline-rich antibacterial peptides.
abstract: Reported here is the isolation and characterization of two antibacterial peptides synthesized in an ant Myrmecia gulosa in response to bacterial challenge. The peptides were purified by reversed-phase high performance liquid chromatography and characterized by peptide sequencing and mass spectrometry. Both peptides were formed from 16 amino acids, were rich in proline ( approximately 30%), and had N-acetylgalactosamine O-linked to a conserved threonine. The activity of a synthetic non-glycosylated isoform was markedly reduced demonstrating that glycosylation was necessary for maximum activity. The peptides were active only against growing Escherichia coli. They were inactive against stationary cells, Gram-positive bacteria, the yeast Candida albicans, two species of mammalian cells, and bovine pestivirus.
authors.affiliation: School of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia. jmackint@rna.bio.mq.edu.au
authors.forename: J A
authors.initials: JA
authors.lastname: Mackintosh
authors.forename: D A
authors.initials: DA
authors.lastname: Veal
authors.forename: A J
authors.initials: AJ
authors.lastname: Beattie
authors.forename: A A
authors.initials: AA
authors.lastname: Gooley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides; D001000:Ants / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000187:drug effects; D006020:Glycopeptides; D006023:Glycoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D006031:Glycosylation; D006458:Hemolymph / Q000737:chemistry; D019476:Insect Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D011392:Proline / Q000032:analysis*; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D006020:Glycopeptides; D006023:Glycoproteins; D019476:Insect Proteins; C111162:formaecin 1 protein, Myrmecia gulosa; C111163:formaecin 2 protein, Myrmecia gulosa; C082117:drosocin; D011392:Proline