Matrix-assisted laser desorption/ionization in-source decay combined with tandem time-of-flight mass spectrometry of permethylated oligosaccharides: targeted characterization of specific parts of the glycan structure.
Matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) has been introduced in recent years as a valuable tool for the structural characterization of permethylated oligosaccharides. In this report, we describe the combination of MALDI in-source decay (ISD) with the subsequent TOF/TOF-MS analyses of specific fragments, allowing the detailed characterization of the selected part of the oligosaccharide molecule. Part of the second-generation fragment ions were different from those observed in conventional MALDI-TOF/TOF-MS experiments. Other fragments, which had already been observed in conventional MALDI-TOF/TOF-MS and again showed up in second-generation fragment analysis, could be assigned to specific parts of the molecule. Our approach disclosed different structural features of the oligosaccharides: due to permethylation, the glycosidic linkage fragments allowed the distinction between terminal, monosubstituted and disubstituted monosaccharides and indicated the oligosaccharide sequence. Moreover, substitution positions were deduced based on characteristic cross-ring fragmentation by high-energy collision-induced fragmentation. In conclusion, combination of MALDI-ISD with TOF/TOF-MS allows the detailed characterization of specific moieties of permethylated oligosaccharides and is, therefore, a powerful technique for structural glycomics.
Wuhrer
Manfred
M
Biomolecular Mass Spectrometry Unit, Department of Parasitology, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. m.wuhrer@lumc.nl
Deelder
André M
AM
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D012550:Schistosoma mansoni / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
D009844:Oligosaccharides; D011134:Polysaccharides