Skip to main content
NCBI home page
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1981 Mar;78(3):1471–1475. doi: 10.1073/pnas.78.3.1471

Field desorption mass spectrometry of oligosaccharides

Michael Linscheid *,†, Jay D'Angona *,†, Alma L Burlingame *,†, Anne Dell ‡, Clinton E Ballou §
PMCID: PMC319152  PMID: 6940169

Abstract

Field desorption mass spectrometry has been used to analyze carbohydrate polymers with 5 to 14 hexose units without prior derivatization. In all examples, the molecular weight of the oligosaccharide could be determined by means of the abundant quasimolecular ions of the type MNa+, MH+, MNa22+, and MNa33+. Fragmentation at glycosidic linkages was observed in varying extents. The reduced oligosaccharide Man8GlcNAcH2, obtained from IgM [Cohen, R. E. & Ballou, C. E. (1980) Biochemistry 19, 4345-4358], gave quasimolecular ion signals MNa+ at m/z 1544, MH+ at m/z 1522, MNa22+ at m/z 784, and MNa33+ at m/z 530, all corresponding to its assumed molecular weight of 1519.5. Mycobacterial methylmannose polysaccharides with the general structure ManxMeMany-OCH3 [Yamada, H., Cohen, R. E. & Ballou, C. E. (1979) J. Biol. Chem. 254, 1972-1979] were also successfully analyzed. Man1MeMan13-OCH3, the largest homolog, gave the expected signal of the quasimolecular ion MNa+ at m/z 2506. The larger polysaccharides were analyzed by using a KRATOS MS-50 mass spectrometer with a high-field magnet enabling full sensitivity to be maintained up to 3000 atomic mass units. Polysaccharides up to m/z 1978 were analyzed by using a KRATOS MS-9 mass spectrometer operated at 4 Kv. The signal-to-noise ratio, which becomes a serious problem in field desorption mass spectrometry at low accelerating voltages, and the low instrument sensitivity were improved considerably by our use of a method of adding scans with low total ion currents obtained over a longer desorption time. In this way, we obtained complete sequence information on methylmannose polysaccharides up to Man1MeMan9-OCH3(MNa+ at m/z 1802). Analysis of a presumed Man1MeMan7-OCH3, gave a spectrum consistent only with the structure Man2MeMan6-OCH3, revealing the existence of a methylmannose homolog with 2 unmethylated mannoses at the nonreducing end of the chain.

Keywords: methylmannose polysaccharide, glycoprotein core oligosaccharide, molecular weight, sequence determination

Full text

PDF
1471

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Budzikiewicz H., Linscheid M. Field ionization mass spectrometry. I--Field desorption spectra of nucleotides--experimental problems. Biomed Mass Spectrom. 1977 Apr;4(2):103–106. doi: 10.1002/bms.1200040209. [DOI] [PubMed] [Google Scholar]
  2. Cohen R. E., Ballou C. E. Linkage and sequence analysis of mannose-rich glycoprotein core oligosaccharides by proton nuclear magnetic resonance spectroscopy. Biochemistry. 1980 Sep 2;19(18):4345–4358. doi: 10.1021/bi00559a031. [DOI] [PubMed] [Google Scholar]
  3. Gray G. R., Ballou C. E. Isolation and characterization of a polysaccharide containing 3-O-methyl-D-mannose from Mycobacterium phlei. J Biol Chem. 1971 Nov 25;246(22):6835–6842. [PubMed] [Google Scholar]
  4. Karlsson K. A., Leffler H., Samuelsson B. E. Characterization of the forssman glycolipid hapten of horse kidney by mass spectrometry. J Biol Chem. 1974 Aug 10;249(15):4819–4823. [PubMed] [Google Scholar]
  5. Kornfeld R., Kornfeld S. Comparative aspects of glycoprotein structure. Annu Rev Biochem. 1976;45:217–237. doi: 10.1146/annurev.bi.45.070176.001245. [DOI] [PubMed] [Google Scholar]
  6. Maitra S. K., Ballou C. E. Heterogeneity and refined structtures of 3-O-methyl-D-mannose polysaccharides from Mycobacterium smegmatis. J Biol Chem. 1977 Apr 25;252(8):2459–2469. [PubMed] [Google Scholar]
  7. Siebertz H. P., Heinz E., Linscheid M., Joyard J., Douce R. Characterization of lipids from chloroplast envelopes. Eur J Biochem. 1979 Nov;101(2):429–438. doi: 10.1111/j.1432-1033.1979.tb19736.x. [DOI] [PubMed] [Google Scholar]
  8. Yamada H., Cohen R. E., Ballou C. E. Characterization of 3-O-methyl-D-mannose polysaccharide precursors in Mycobacterium smegmatis. J Biol Chem. 1979 Mar 25;254(6):1972–1979. [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES