title: Comparison of fragmentation modes for the structural determination of complex oligosaccharides ionized by matrix-assisted laser desorption/ionization mass spectrometry.
abstract: Fragment ions from underivatized N-linked oligosaccharides ionized by matrix-assisted laser desorption/ionization mass spectrometry were obtained by spontaneous fragmentation on a magnetic sector mass spectrometer, by post-source decay (PSD) on a reflectron time-of-flight (TOF) instrument and by collision-induced dissociation on a magnetic sector instrument fitted with an orthagonal-TOF analyser. Spontaneous fragmentation on the magnetic sector instrument produced ions mainly by glycosidic cleavage together with two abundant ions formed by cross-ring cleavage of the reducing-terminal residue. The PSD spectra were similar, the majority of ions being formed by glycosidic cleavage. Internal fragment ions were abundant. High-energy collision-induced dissociation spectra recorded with the orthagonal-TOF analyser, differed considerably from the other types of spectra, particularly in the appearance of major fragment ions produced by cross-ring cleavages of most of the constituent monosaccharide residues. These ions allowed much sequence and branching information to be obtained from the oligosaccharide.
authors.affiliation: Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Harvey
authors.forename: T J
authors.initials: TJ
authors.lastname: Naven
authors.forename: B
authors.initials: B
authors.lastname: Küster
authors.forename: R H
authors.initials: RH
authors.lastname: Bateman
authors.forename: M R
authors.initials: MR
authors.lastname: Green
authors.forename: G
authors.initials: G
authors.lastname: Critchley
mesh_terms: D002240:Carbohydrate Sequence; D005697:Galactosides / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis*
chemical_list: D005697:Galactosides; D009844:Oligosaccharides