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bioRxiv · 10.1101/2020.12.13.422539

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

Wang, S.-S.·del Solar, V.·Yu, X.·Antonopoulos, A.·Friedman, A. E.·Agarwal, K.·Garg, M.·Ahmed, S. M.·Addya, A.·Nasirikenari, M.·Lau, J. T.·Dell, A.·Haslam, S. M.·Sampathkumar, S.-G.·Neelamegham, S.
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Abstract

There is a critical need to develop small molecule inhibitors of mucin-type O-linked glycosylation. The best known reagent currently is peracetylated benzyl-GalNAc, but it is only effective at millimolar concentrations. This manuscript demonstrates that Ac5GalNTGc, a peracetylated C-2 sulfhydryl substituted GalNAc, fulfills this unmet need. When added to cultured leukocytes, breast 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 demonstrate that 50-80M Ac5GalNTGc prevented elaboration of 30-60% of the O-glycans beyond the Tn-antigen (GalNAc1-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. 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.

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Wang, S.-S., del Solar, V., Yu, X., Antonopoulos, A., Friedman, A. E., Agarwal, K., Garg, M., Ahmed, S. M., Addya, A., Nasirikenari, M., Lau, J. T., Dell, A., Haslam, S. M., Sampathkumar, S.-G., Neelamegham, S.. 2020-12-13. Efficient Inhibition of O-glycan biosynthesis using the hexosamine analog Ac5GalNTGc. https://doi.org/10.1101/2020.12.13.422539

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