title: Fast screening of highly glycosylated plant sphingolipids by tandem mass spectrometry.
abstract: The structural characterization of Glycosyl-Inositol-Phospho-Ceramides (GIPCs), which are the main sphingolipids of plant tissues, is a critical step towards the understanding of their physiological function. After optimization of their extraction, numerous plant GIPCs have been characterized by mass spectrometry. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) full scan analysis of negative ions provides a quick overview of GIPC distribution. Clear differences were observed for the two plant models studied: six GIPC series bearing from two to seven saccharide units were detected in tobacco BY-2 cell extracts, whereas GIPCs extracted from A. thaliana cell cultures and leaves were less diverse, with a dominance of species containing only two saccharide units. The number of GIPC species was around 50 in A. thaliana and 120 in tobacco BY-2 cells. MALDI-MS/MS spectra gave access to detailed structural information relative to the ceramide moiety, the polar head, as well as the number and types of saccharide units. Once released from GIPCs, fatty acid chains and long-chain bases were analyzed by GC/MS to verify that all GIPC series were taken into account by the MALDI-MS/MS approach. ESI-MS/MS provided complementary information for the identification of isobaric species and fatty acid chains. Such a methodology, mostly relying on MALDI-MS/MS, should open new avenues to determine structure-function relationships between glycosphingolipids and membrane organization.
authors.affiliation: Université de Bordeaux, Chimie Biologie des Membranes et Nanoobjets CBMN-UMR 5248, Centre de Génomique Fonctionnelle Université Bordeaux 2, Bordeaux, France. c.bure@cbmn.u-bordeaux.fr
authors.forename: Corinne
authors.initials: C
authors.lastname: Buré
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Cacas
authors.forename: Fen
authors.initials: F
authors.lastname: Wang
authors.forename: Karen
authors.initials: K
authors.lastname: Gaudin
authors.forename: Frédéric
authors.initials: F
authors.lastname: Domergue
authors.forename: Sébastien
authors.initials: S
authors.lastname: Mongrand
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Schmitter
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D002518:Ceramides / Q000032:analysis / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D010944:Plants / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors; D014026:Nicotiana / Q000737:chemistry / Q000166:cytology / Q000378:metabolism
chemical_list: D002518:Ceramides; D009844:Oligosaccharides