Primary structure and in vitro antibacterial properties of the Drosophila melanogaster attacin C Pro-domain.
In Drosophila melanogaster, seven distinct families of antimicrobial peptides with different structures and specificities are synthesized by the fat body and released into the hemolymph during the immune response. Using microscale high performance liquid chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and Edman degradation, we have isolated and characterized from immune-challenged Drosophila two novel induced molecules, under the control of the Imd pathway, that correspond to post-translationally modified antimicrobial peptides or peptide fragments. The first molecule is a doubly glycosylated form of drosocin, an O-glycosylated peptide that kills Gram-negative organisms. The second molecule represents a truncated form of the pro-domain of the Drosophila attacin C carrying two post-translational modifications and has significant structural similarities to proline-rich antibacterial peptides including drosocin. We have synthesized this peptide and found that it is active against Gram-negative bacteria. Furthermore, this activity is potentiated when the peptide is used in combination with the Drosophila antimicrobial peptide cecropin A. The synergistic action observed between these two molecules suggests that the truncated post-translationally modified pro-domain of attacin C by itself may play an important role in the antimicrobial defense of Drosophila.
Rabel
David
D
Institut de Biologie Moléculaire et Cellulaire, UPR9022, CNRS, 15 Rue René Descartes, 67084 Strasbourg Cedex, France.
Charlet
Maurice
M
Ehret-Sabatier
Laurence
L
Cavicchioli
Lionel
L
Cudic
Mare
M
Otvos
Laszlo
L
Bulet
Philippe
P
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000378:metabolism*; D016972:Enterobacter cloacae / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D006020:Glycopeptides / Q000737:chemistry; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006458:Hemolymph / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; C488990:AttA protein, Drosophila; C488991:AttB protein, Drosophila; C488989:AttC protein, Drosophila; D029721:Drosophila Proteins; D006020:Glycopeptides; D019476:Insect Proteins; D010455:Peptides; C039711:attacin antibacterial protein, insect; C082117:drosocin; C031161:cecropin A