Collision-induced dissociation of alkali metal cationized and permethylated oligosaccharides: Influence of the collision energy and of the collision gas for the assignment of linkage position

Abstract

Tandem mass spectrometry has been used to study the collision-induced decomposition of [M+Na](+) ions of permethylated oligosaccharides. It is shown that many linkage positions in one compound may be determined by the presence or absence, in a single spectrum, of specific fragment ions that arise from the cleavage of two ring bonds and that the yield of such ions depends strongly on the collision energy and nature of the collision gas. In contrast to the behavior of monolithiated native oligosaccharides, the collision-induced decomposition of the sodiated and permethylated oligosaccharide samples at low energy leads to preferential cleavage of glycosidic linkages. At high collision energies, the fragment ions formed by cleavage of more than one bond are greatly enhanced, especially when helium is replaced by argon as the collision gas. Furthermore, argon is the more efficient collision gas in inducing fragmentation of the precursor ions. As an example of the application of this method, the discrimination between the 1 → 3 and 1 → 6-linked mannose residues in the common core of N-glycans is described.

Distinguishing Monosaccharide Stereo- and Structural Isomers with TOF-SIMS and Multivariate Statistical Analysis

“…DeJongh's 10 assignment of m/z = 57 to HO and Biemann's 7 assignment of m/z = 43 to CH 3 CO + are similarly confirmed. Alkali metal cationization of monosaccharides is well known, 19,21,24 suggesting that the relatively small peak at m/z = 203 is due to the [M+Na] + adduct and the similar m/z = 219 peak most evident in the psicose spectrum is due to the…”

Gas-phase oligosaccharide nonreducing end (GONE) sequencing and structural analysis by reversed phase hplc/mass spectrometry with polarity switching

“…In the positive ion mode, metal cationized oligosaccharide ions were found to produce cross-ring cleavages at higher abundance than protonated ions [11,14]. However, extensive cross-ring cleavages were observed for sodiated ions only under high-energy collision conditions (ϳ1 keV or higher) [15][16][17][18][19][20][21][22][23][24][25]. In the negative ion mode, cross-ring cleavage was found to be abundant for either deprotonated or anion adduct ions under both high [24] and low [26 -36] energy CID conditions.…”

Collisional Activation Dissociation Mass Spectrometry Studies of Oligosaccharides Conjugated with Na+-Encapsulated Dibenzo-18-Crown-6 Ether

“…This difference suggests that Na + immobilization activated different oligosaccharide fragmentation pathways, more likely enhancing the charge-remote fragmentation pathways compared with the charge-directed pathways. 13,[17][18][19] However, as mentioned earlier, the observation of (sodiated) B and C series fragments implies that Na + migration to the sugar unit from the dibenzo-18-crown-6 ether occurs albeit to a limited extent. Nevertheless, from these observations, it can be deduced that a cationization agent, either H + or Na + , and the immobilization of Na + strongly affect the oligosaccharide fragmentation pathways.…”

“…These spectra clearly indicate that the fragmentation patterns are quite different, consistent with previous literature reports. 16,18,19 For the protonated maltose ions, a peak originating from OH loss is dominant, followed by glycosidic bond cleavage products such as B 1 and Y 1 . It is also notable that cross-ring cleavage products, such as 3,5 X 2 and 2,5 X 2 , are observed in significant amounts (Here, the glycan fragments are annotated according to the nomenclature of Domon and Costello).…”

“…On the other hand, crossring cleavage occurs through the charge-remote fragmentation pathways. 13,[17][18][19] However, the effect of an alkali metal ion, e.g., Na + , which is localized and immobilized at a certain position of the oligosaccharide species, has not been investigated. The immobilization of Na + can be achieved by covalently incorporating a dibenzo-18-crown-6 ether that is known to form stable complexes with Na + (see Scheme 1).…”