Gas-phase fragmentation studies of biotinylated, hexaethylene glycol-spacered oligosaccharides — molecular probes — using electrospray mass spectrometry on hybrid high-resolution mass spectrometer
T13N3
A.O. Chizhov, D.A. Argunov, M.L. Gening, E.V. Sukhova, E.A. Khatuntseva, A.A. Karelin,
B.S. Komarova, M.V. Orekhova, V.B. Krylov, D.V. Yasunskii, Yu.E. Tsvetkov, N.E. Nifantiev
Electrospray ionization high-resolution mass spectra of biotinylated, hexaethylene glycol spacered molecular probes bearing biologically relevant carbohydrate moieties in positive and negative modes were recorded and interpret. Collisionally-induced decay mass spectra (positive mode) reveal different patterns depending on the charge of the parent ion, attached cations (or ions), the composition, and the sequence of carbohydrate fragment. The most intense peaks (two series) originate from the sequential cleavage of glycoside bonds resulting in charge location on the “reducing” end (Y series, observed for all compounds studied) or “non-reducing” end (B series). Fragmentation of the hexaethylene glycol chain giving rise to the cleavage of the C—O bond remoted from the biotin moiety is observed. Other fragment ions lighter than the mentioned above on the difference of (C2H4O)n were absent or much smaller. Similar fragmentation was found for all of the non-sulfated, biotinylated glycosides with the hexaethylene glycol spacer thus demonstrating that this type of fragmentation was characteristic for such molecular probes. Similar cleavages along with decay of biotin moiety via elimination of H2S and H2CS were observed for negative ions in collisionally-induced decay mass spectra of sulfated and neutral molecular probes.
