Efficient inhibition of O-glycan biosynthesis using the hexosamine analog Ac5GalNTGc

  • Cell Chem Biol. 2021 May 20;28(5):699-710.e5. doi: 10.1016/j.chembiol.2021.01.017.
Shuen-Shiuan Wang  1 ,  Virginia Del Solar  1 ,  Xinheng Yu  1 ,  Aristotelis Antonopoulos  2 ,  Alan E Friedman  3 ,  Kavita Agarwal  4 ,  Monika Garg  4 ,  Syed Meheboob Ahmed  4 ,  Ahana Addhya  4 ,  Mehrab Nasirikenari  5 ,  Joseph T Lau  5 ,  Anne Dell  2 ,  Stuart M Haslam  2 ,  Srinivasa-Gopalan Sampathkumar  6 ,  Sriram Neelamegham  7
Affiliations
  • 1. Department of Chemical and Biological Engineering, State University of New York, 906 Furnas Hall, Buffalo, NY, USA.
  • 2. Department of Life Sciences, Imperial College London, London, UK.
  • 3. Department of Chemistry, State University of New York, Buffalo, NY, USA.
  • 4. Laboratory of Chemical Glycobiology, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India.
  • 5. Department of Cellular and Molecular Biology, Roswell Park Cancer Institute, Buffalo, NY, USA.
  • 6. Laboratory of Chemical Glycobiology, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110067, India. Electronic address: [email protected].
  • 7. Department of Chemical and Biological Engineering, State University of New York, 906 Furnas Hall, Buffalo, NY, USA; Department of Medicine, State University of New York, Buffalo, NY, USA. Electronic address: [email protected].
PMID: 33609441 DOI: 10.1016/j.chembiol.2021.01.017
Abstract

There is a critical need to develop small-molecule inhibitors of mucin-type O-linked glycosylation. The best-known reagent currently is benzyl-GalNAc, but it is effective only at millimolar concentrations. This article demonstrates that Ac5GalNTGc, a peracetylated C-2 sulfhydryl-substituted GalNAc, fulfills this unmet need. When added to cultured leukocytes, breast cells, and prostate cells, Ac5GalNTGc increased cell-surface VVA binding by ∼10-fold, indicating truncation of O-glycan biosynthesis. Cytometry, mass spectrometry, and western blot analysis of HL-60 promyelocytes demonstrated that 50-80 μM Ac5GalNTGc prevented elaboration of 30%-60% of the O-glycans beyond the Tn-antigen (GalNAcα1-Ser/Thr) stage. The effect of the compound on N-glycans and glycosphingolipids was small. Glycan inhibition induced by Ac5GalNTGc resulted in 50%-80% reduction in leukocyte sialyl-Lewis X expression and L-/P-selectin-mediated rolling under flow conditions. Ac5GalNTGc was pharmacologically active in mouse. It reduced neutrophil infiltration to sites of inflammation by ∼60%. Overall, Ac5GalNTGc may find diverse applications as a potent inhibitor of O-glycosylation.

Keywords
O-glycan; cell adhesion; glycosylation; inflammation; inhibitor; mucin; neutrophil; selectin; sialyl-Lewis X; small molecule.
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