A novel insect defensin from the ant Formica rufa.
By combination of size exclusion and reversed-phase chromatography, we have isolated a novel member of insect defensin-type antimicrobial peptides from the entire bodies of bacteria-challenged Formica rufa (hymenoptera, formicidae). The molecular mass of the purified peptide was estimated to be 4120.42 by matrix-assisted laser desorption/ionization-time of flight/mass spectrometry. Sequence analysis revealed that this peptide consisted of 40 amino acid residues with six cysteines engaged in the formation of three intramolecular disulfide bridges. This peptide is unique among the arthropod defensins in terms of the presence of asparatic acid and alanine at position 33 and as C-terminal residue, respectively. In addition, this novel defensin from Formica rufa has the particularity to have no C-terminal extension in contrast to those reported for other hymenoptera defensins.
Department of Biological Science and Technology, Science University of Tokyo, Chiba, Japan.
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Taguchi
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Bulet
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Hoffmann
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000302:isolation & purification; D001000:Ants / Q000382:microbiology* / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D019476:Insect Proteins / Q000737:chemistry* / Q000302:isolation & purification; D007313:Insecta; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
D000900:Anti-Bacterial Agents; D019476:Insect Proteins; C114458:defensin protein, Formica rufa