Structure-based design of UDP-GlcNAc analogs as candidate GnT-V inhibitors.

Vibhute, Amol M, Hide-Nori Tanaka, Sushil K Mishra, Reina F Osuka, Masamichi Nagae, Chizuko Yonekawa, Hiroaki Korekane, Robert J Doerksen, Hiromune Ando, and Yasuhiko Kizuka. 2022. “Structure-Based Design of UDP-GlcNAc Analogs As Candidate GnT-V Inhibitors.”. Biochimica et Biophysica Acta. General Subjects 1866 (6): 130118.

Abstract

BACKGROUND: N-Glycan branching regulates various functions of glycoproteins. N-Acetylglucosaminyltransferase V (GnT-V) is a GlcNAc transferase that acts on N-glycans and the GnT-V-producing branch is highly related to cancer progression. This indicates that specific GnT-V inhibitors may be drug candidates for cancer treatment. To design novel GnT-V inhibitors, we focused on the unique and weak recognition of the donor substrate UDP-GlcNAc by GnT-V. On the basis of the catalytic pocket structure, we hypothesized that UDP-GlcNAc analogs with increasing hydrophobicity may be GnT-V inhibitors.

METHODS: We chemically synthesized 10 UDP-GlcNAc analogs in which one or two phosphate groups were replaced with hydrophobic groups. To test these compounds, we set up an HPLC-based enzyme assay system for all N-glycan-branching GlcNAc transferases in which GnT-I-V activity was measured using purified truncated enzymes. Using this system, we assessed the inhibitory effects of the synthesized compounds on GnT-V and their specificity.

RESULTS: Several UDP-GlcNAc analogs inhibited GnT-V activity, although the inhibition potency was modest. Compared with other GnTs, these compounds showed a preference for GnT-V, which suggested that GnT-V was relatively tolerant of hydrophobicity in the donor substrate. Docking models of the inhibitory compounds with GnT-V suggested the mechanisms of how these compounds interacted with GnT-V and inhibited its action.

CONCLUSIONS: Chemical modification of the donor substrate may be a promising strategy to develop selective inhibitors of GnT-V.

GENERAL SIGNIFICANCE: Our findings provide new insights into the design of GnT inhibitors and how GnTs recognize the donor substrate.

Last updated on 06/16/2025
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