ANALYSIS OF GLYCOSAMINOGLYCANS USING ESI-QQQ-FTMS

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The new ESI-qQq-FTMS has demonstrated the ability to analyze labile post-translational modifications (PTMs) on peptides and proteins using a variety of tandem mass spectrometry methods such as Q2-CAD, SORI-CAD, and ECD. It has also been used for negative ion EDD experiments. The ability to ionize and analyze molecules containing labile PTMs and the ability to use negative ion-electron reactions to do radical-based fragmentation suggests interesting capailities for the analysis of glycosaminoglycans. Due to the lability of he sulfate moieties on glycosaminoglycans, it has generally been difficult to ionize these molecules without loss of sulfates. However, initial experiments with the ESI-qQq-FTMS have shown that ionization of intact glycosaminoglycans is not particularly difficult if one carefully tunes the front end to minimize fragmentation. Further experiments are ongoing to then apply the flexibility of this instrument to the full analysis of these complex molecules using the full array of technigues from selected isolation and accumulation to EDD, ECD, and CAD methods that have been shown to be effective in full analysis of proteins and peptides. EDD is particularly useful and shows strong, clear crossring cleavages for negative glycosaminoglycan ions. Several examples have been generated and the manuscript is being prepared.