Energy-resolved collision-induced dissociation pathways of model N-linked glycopeptides: implications for capturing glycan connectivity and peptide sequence in a single experiment

Abstract

"Energy-resolved collision-induced dissociation pathways of model N-linked glycopeptides: implications for capturing glycan connectivity and peptide sequence in a single experiment" (2014). Faculty Publications --Chemistry Department. 68. http://digitalcommons.unl.edu/chemfacpub/68Energy-resolved collision-induced dissociation pathways of model N-linked glycopeptides: implications for capturing glycan connectivity and peptide sequence in a single experiment † Venkata Kolli and Eric D. Dodds * Tandem mass spectrometry (MS/MS) of glycopeptides stands among the principal analytical approaches for assessing protein glycosylation in a site-specific manner. The aims of such experiments are often to determine the monosaccharide connectivity of the glycan, the amino acid sequence of the peptide, and the site of glycan attachment. This level of detail is often difficult to achieve using any single ion dissociation method; however, precedent does exist for use of collision-induced dissociation (CID) to establish either the connectivity of the oligosaccharide or the sequence of the polypeptide depending upon the applied collision energy. Unfortunately, the relative energy requirements for glycan and peptide cleavage have not been thoroughly characterized with respect to specific physicochemical characteristics of the precursor ions. This report describes case studies on the energy-resolved CID pathways of model tryptic glycopeptides derived from Erythrina cristagalli lectin and bovine ribonuclease B. While glycopeptide ions having disparate physical and chemical characteristics shared strikingly similar qualitative responses to increasing vibrational energy deposition, the absolute collision energies at which either glycan or peptide fragmentations were accessed varied substantially among the precursor ions examined. Nevertheless, these data suggest that the energy requirements for peptide and glycan cleavage may be somewhat predictable based on characteristics of the precursor ion. The practical usefulness of these observations was demonstrated through implementation of online collision energy modulation such that both glycan and peptide fragmentation were captured in the same spectrum, providing near-exhaustive glycopeptide characterization in a single experiment. Overall, these results highlight the potential to further extend the capabilities of CID in the context of glycoproteomics.

A Comparison of Energy-Resolved Vibrational Activation/Dissociation Characteristics of Protonated and Sodiated High Mannose N-Glycopeptides

“…The Y 1 glycan fragment (i.e., the peptide group with one remaining GlcNAc residue attached) was also observed, and by a significant margin constituted the most abundant fragment ion in this spectrum. This is consistent with previous observations that cleavage between the two GlcNAc residues of the N-linked glycan core is a favored process [14][15][16][17][18]. Under these conditions, the CID spectrum of the hybrid protonated sodium adduct (Figure 4b) was highly distinct from that of the doubly protonated precursor.…”

“…Substantial effort has been directed towards exploiting the specific advantages afforded by different ion dissociation methods for glycopeptide analysis, including those based on ion-neutral interactions, as in collision-induced dissociation (CID) [14][15][16][17][18]; ion-electron and ion-ion reactions, as in electron capture dissociation (ECD) and electron transfer dissociation (ETD) [19][20][21][22]; and irradiation with photons, as in infrared multiphoton dissociation (IRMPD) and ultraviolet photodissociation (UVPD) [23][24][25][26]. By comparison, less attention has been paid to the effects of charge carrier upon glycopeptide dissociation patterns and energetics.…”

A case for protein-level and site-level specificity in glycoproteomic studies of disease

“…Second, multiple MS/MS ion dissociation techniques are often needed to allow for characterization of both the glycan and peptide moieties of glycopeptides [44,45]. There have been many advances in this area, where either the combination of two dissociation techniques or the use of a single technique such as energy-resolved collision-induced dissociation (CID) or ultraviolet photon dissociation (UVPD) allows for complete characterization of glycopeptide structure [46][47][48][49]. For these reasons, site-specific glycoproteomic analysis of disease is only recently gaining the level of momentum that other, less specific approaches have gathered to date.…”

Addressing the glycan complexity by using mass spectrometry: In the pursuit of decoding glycologic

“…Based on the observation of individual product ions, it was reported that structural discrimination was possible in the LC-TQ MS system [76]. Further increase in the CID energy results in the breaking down of the backbone peptide linkage and enables the peptide sequence analysis in an ERMS experiment cycle [77]. Therefore, ERMS is a quite useful technique in the glycoproteomics research as well.…”