title: Identification of new immune induced molecules in the haemolymph of Drosophila melanogaster by 2D-nanoLC MS/MS.
abstract: Antimicrobial peptides (AMPs) play an important role in the innate immunity of insects. In Drosophila 17 additional immune induced molecules (DIMs) were found in the haemolymph of adult flies upon septic injury. Previous studies using MALDI mass spectrometry combined with Edman degradation, detected AMPs and DIMs of a predominantly large size. By means of 2D-nanoLC ESI MS/MS, 43 DIMs were identified in this study from the haemolymph of Drosophila third instar larvae 12h after challenge with a mixture of Micrococcus luteus and Escherichia coli. Most peptides were derived from known AMP or DIM precursors, but only four peptides were purified and identified before. The majority of the peptides that we detected were smaller in size. Interestingly, two previously unknown peptide precursors were found and hereby related to immune defense. These include CG7738 and CG32185. Many of the identified peptides are post-translationally modified by an N-terminal pyroglutamic acid and/or a C-terminal amide. Haemolymph of control larvae was treated in the same way and revealed only one peptide.
authors.affiliation: Laboratory of Developmental Physiology, Genomics and Proteomics, K.U.Leuven, Naamsestraat 59, B-3000 Leuven, Belgium. peter.verleyen@bio.kuleuven.ac.be
authors.forename: Peter
authors.initials: P
authors.lastname: Verleyen
authors.forename: Geert
authors.initials: G
authors.lastname: Baggerman
authors.forename: Wannes
authors.initials: W
authors.lastname: D'Hertog
authors.forename: Evy
authors.initials: E
authors.lastname: Vierstraete
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Husson
authors.forename: Liliane
authors.initials: L
authors.lastname: Schoofs
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000276:immunology*; D004926:Escherichia coli; D006458:Hemolymph / Q000276:immunology*; D007814:Larva / Q000276:immunology; D016982:Micrococcus luteus; D008969:Molecular Sequence Data; D010455:Peptides / Q000097:blood; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D029721:Drosophila Proteins; D010455:Peptides