Discrimination of Isomeric Fragment Ions Observed in Tandem Mass Spectra of Biantennary Oligosaccharides by Use of Selective Isotope Labeling

Dissociation Profile of Protonated Fucosyl Glycopeptides and Quantitation of Fucosylation Levels of Glycoproteins by Mass Spectrometry

“…The major dissociation pathway in CID was found to be the cleavage of a GlcNAcβ1→2Man linkage in either of the isoforms. A preferential cleavage of this linkage in the Manα1→6 antenna as compared with the Manα1→3 antenna has been reported for the [M + Na] + ions of the reductively aminated biantennary oligosaccharides by means of isotopic labeling of either antenna. , This rule cannot be applied directly to glycopeptides, because the dissociation of protonated and alkali-cationized ions occurs through different mechanisms each other.…”

Stable-isotope-assisted NMR approaches to glycoproteins using immunoglobulin G as a model system

“…Applicability of the stable-isotope-labeling methods of glycans is not limited to the field of NMR studies. For example, the branchspecific in vitro 13 C-labeling of multi-antennary oligosaccharides have offered a novel mass spectrometric approach to provide the basis for the mechanisms of formation of glycosidic linkage fragment ions [95].…”

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“…However, we might discriminate each antenna if branch-selective 13 C labeling of sugar residue is applied to oligosaccharides. We have succeeded in mass spectrometric analyses of biantennary oligosaccharides, in which one of two non-reducing terminal galactose residue is selectively enriched with 13 C by enzymatic reactions (74). Interestingly, a preferential cleavage of the GlcNAcb1-2Man glycosidic linkage in the Mana1-6 antenna was observed compared with the cleavage in Mana1-3 antenna.…”