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@article{bulet_insect_1995,

title = {Insect immunity. The inducible antibacterial peptide diptericin carries two O-glycans necessary for biological activity},

author = {Philippe Bulet and G Hegy and J Lambert and Alan van Dorsselaer and Jules A Hoffmann and Charles Hetru},

issn = {0006-2960},

year  = {1995},

date = {1995-06-01},

journal = {Biochemistry},

volume = {34},

number = {22},

pages = {7394--7400},

abstract = {A bacterial challenge of larvae of the dipteran insect Phormia terranovae induces the rapid synthesis of diptericin, an antibacterial polypeptide, previously characterized at the amino acid level and indirectly by cDNA cloning studies. This 82-residue polypeptide consists of an N-terminal proline-rich domain and a central and C-terminal glycine-rich domain. Using liquid chromatography coupled to electrospray ionization-mass spectrometry, we demonstrate here that this molecule is more complex than anticipated and carries two O-substitutions on threonine residues, one in the proline-rich domain (residue 10) and one in the glycine-rich domain (residue 54). These substitutions consist of identical trisaccharides: glucose--textgreatergalactose--textgreaterN-acetylgalactosamine--textgreater(threonine). Treatment of diptericin with O-glycosidase, which selectively removes the substitutions without altering the polypeptide proper, abolishes the antibacterial activity, indicating that this posttranslational modification is essential for biological activity of the polypeptide. We also show that diptericin is posttranslationally modified by a C-terminal amidation.},

keywords = {Animals, Anti-Bacterial Agents, Carbohydrate Sequence, Carbohydrates, Diptera, Escherichia coli, Glycopeptides, Hemolymph, hoffmann, Insect Hormones, Insect Proteins, Larva, M3i, Mass Spectrometry, Plants, Trisaccharides},

pubstate = {published},

tppubtype = {article}

}

@article{bulet_novel_1993,

title = {A novel inducible antibacterial peptide of Drosophila carries an O-glycosylated substitution},

author = {Philippe Bulet and Jean-Luc Dimarcq and Charles Hetru and Marie Lagueux and Maurice Charlet and G Hegy and Alan Van Dorsselaer and Jules A Hoffmann},

issn = {0021-9258},

year  = {1993},

date = {1993-07-01},

journal = {J. Biol. Chem.},

volume = {268},

number = {20},

pages = {14893--14897},

abstract = {One of the facets of the host defense of higher insects is the rapid and transient synthesis, following bacterial challenge or trauma, of a battery of potent antibacterial peptides (Steiner, H., Hultmark, D., Engström, A., Bennich, H., and Boman, H. G. (1981) Nature 292, 246-248). The best characterized of these peptides are the cecropins (ibid.), 4-kDa peptides devoid of cysteines, and the insect defensins (Hoffmann, J. A., and Hetru, C. (1992) Immunol. Today 13, 411-415), 4-kDa peptides with three intramolecular disulfide bridges. Several other inducible antibacterial peptides have been characterized only at the level of their amino acid sequences (Hoffmann, J. A., Dimarcq, J. L., and Bulet, P. (1992) Médecine & Sciences 8, 432-439). We report here the isolation of a novel 19-residue proline-rich inducible antibacterial peptide from Drosophila. In contrast to all previous reports on antibacterial peptides, this molecule carries a substitution as evidenced by molecular mass determinations; our data show that this reflects the O-glycosylation of a Thr residue by an N-acetylgalactosamine plus a galactose. A synthetic nonsubstituted peptide of identical amino acid sequence has an activity several times lower (5-10) than the native compound. Our data suggest that this substitution represents a post-translational modification essential for the full biological activity of this novel peptide.},

keywords = {Animals, Anti-Bacterial Agents, Base Sequence, Carbohydrates, Cloning, DNA, Escherichia coli, Gas Chromatography-Mass Spectrometry, Glycopeptides, Glycosylation, hoffmann, M3i, Molecular},

pubstate = {published},

tppubtype = {article}

}