Linkage position and nonreducing end residues (glucose, galactose, and mannose) determination of disaccharides by graphite assisted laser desorption/ionization and tandem mass spectrometry

CARB 82

Hui Zhang, huizh@iastate.edu1, Ning Fang, nfang@iastate.edu1, Steve M. Brokman, sbrokman@iastate.edu2, Nicola L. Pohl, npohl@iastate.edu2, and Edward S. Yeung, yeung@ameslab.gov1. (1) Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, 035A Carver Co-lab, Iowa State University, Ames, IA 50011-3650, (2) Department of Chemistry and the Plant Sciences Institute, Iowa State University, Gilman Hall, Ames, IA 50011
Conventional MALDI MS has strong interference peaks from matrix ions in low mass region (<500 Da). This greatly limits the application of MALDI MS for analysis of small oligosaccharides. Graphite assisted laser desorption/ionization (GALDI) MS has proven suitable for small molecules analysis as they give very clean background in the low mass region. In this study GALDI MS in combination with tandem MS is used to differentiate the linkage position of isomeric disaccharides. Disaccharides with different linkage type give different tandem mass profiles from various cross-ring fragmentation pathways. The profiles are very similar to the results from electrospray tandem mass spectrometry. Disaccharides with the same linkage type but different non-reducing end residues (such as glucose, galactose, and mannose) bear the same fragmentation profiles. However, the relative abundance of fragments was distinctively different among these three and this enables the differentiation of those disaccharides with different non-reducing end residues.
 

General Posters
6:00 PM-8:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Carbohydrate Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007