Isolation from an ant Myrmecia gulosa of two inducible O-glycosylated proline-rich antibacterial peptides.
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.
Mackintosh
J A
JA
School of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia. jmackint@rna.bio.mq.edu.au
Veal
D A
DA
Beattie
A J
AJ
Gooley
A A
AA
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
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