NMR detection and characterization of sialylated glycoproteins and cell surface polysaccharides

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NMR detection and characterization of sialylated glycoproteins and cell surface polysaccharides


Abstract Few solution NMR pulse sequences exist that are explicitly designed to characterize carbohydrates (glycans). This is despite the essential role carbohydrate motifs play in cellâ??cell communication, microbial pathogenesis, autoimmune disease progression and cancer metastasis, and despite that fact that glycans, often shed to extra-cellular fluids, can be diagnostic of disease. Here we present a suite of two dimensional coherence experiments to measure three different correlations (H3â??C2, H3â??C1, and C1â??C2) on sialic acids, a group of nine-carbon carbohydrates found on eukaryotic cell surfaces that often play a key role in disease processes. The chemical shifts of the H3, C2, and C1 nuclei of sialic acids are sensitive to carbohydrate linkage, linkage conformation, and ionization state of the C1 carboxylate. The experiments reported include rigorous filter elements to enable detection and characterization of isotopically labeled sialic acids with high sensitivity in living cells and crude isolates with minimal interference from unwanted signals arising from the ~1% 13C-natural abundance of cellular metabolites. Application is illustrated with detection of sialic acids on living cells, in unpurified mixtures, and at the terminus of the N-glycan on the 55 kDa immunoglobulin G Fc.

• Content Type Journal Article
• Category Article
• Pages 163-171
• DOI 10.1007/s10858-011-9550-0
• Authors
  • Adam W. Barb, Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA
  • Darón I. Freedberg, Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29, Room 115, 1401 Rockville Pike, HFM-428, Rockville, MD 20852, USA
  • Marcos D. Battistel, Laboratory of Bacterial Polysaccharides, Center for Biologics Evaluation and Research, Food and Drug Administration, Building 29, Room 115, 1401 Rockville Pike, HFM-428, Rockville, MD 20852, USA
  • James H. Prestegard, Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602, USA

• • Journal Journal of Biomolecular NMR
  • Online ISSN 1573-5001
  • Print ISSN 0925-2738
  • Journal Volume Volume 51
  • Journal Issue Volume 51, Numbers 1-2

Source: Journal of Biomolecular NMR