GlcNAcstatin

GlcNAcstatin is a highly potent and competitive inhibitor of O-GlcNAcase (OGA) with Ki value of 4.4 nM for human OGA [1].

GlcNAcstatin is a synthetic GlcNAc-configured nagstatin derivative with a larger isobutanamido group on N8 and a phenethyl group on C2. It inhibited bacterial OGA with Ki value of 4.6 pM. For human OGA, GlcNAcstatin also showed a potent inhibition with Ki value of 4.4 nM. Besides that, GlcNAcstatin exerted inhibitory activity against human lysosomal Hex A/B with Ki value of 550 nM, suggesting that it is a selective inhibitor of OGA. In HEK293 cells, treatment of GlcNAcstatin at concentration of 20 nM resulted in increased cellular O-GlcNAc levels of many proteins. GlcNAcstatin also significantly prevented O-GlcNAc from binding to proteins in SH-SY5Y human neuroblastoma cell lysates [1, 2].

References:
[1] Dorfmueller H, Borodkin V, Schimpl M, et al. GlcNAcstatins are nanomolar inhibitors of human O-GlcNAcase inducing cellular hyper-O-GlcNAcylation. Biochem. J, 2009, 420: 221-227.
[2] Dorfmueller H C, Borodkin V S, Schimpl M, et al. GlcNAcstatin: a picomolar, selective O-GlcNAcase inhibitor that modulates intracellular O-glcNAcylation levels. Journal of the American Chemical Society, 2006, 128(51): 16484-16485.

Protein-ligand interaction study of CpOGA in complex with GlcNAcstatin.[Pubmed:23066949]

Chem Biol Drug Des. 2013 Feb;81(2):284-90.

The GlcNAcstatin is a potent inhibitor of O-glycoprotein 2-acetamino-2-deoxy-beta-D-glucopyranosidase, which has been related with type II diabetes and neurodegenerative disorders. Herein, hybrid quantum mechanics/molecular mechanics, molecular dynamics simulations, and potential of mean force were employed to study the interactions established between GlcNAcstatin and a bacterial O-GlcNAcase enzyme from Clostridium perfringens. The results reveal that the imidazole nitrogen atom of GlcNAcstatin has shown a better interaction with the active site of Clostridium perfringens in its protonated form, which is compatible with a substrate-assisted reaction mechanism involving two conserved aspartate residues (297 and 298). Furthermore, the quantum mechanics/molecular mechanics-molecular dynamics simulations appointed a strong interaction between Asp401, Asp298, and Asp297 residues and the GlcNAcstatin inhibitor, which is in accordance with experimental data. Lastly, these results may contribute to understand the molecular mechanism of inhibition of Clostridium perfringens by GlcNAcstatin inhibitor and, consequently, this study might be useful to design new molecules with more interesting inhibitory activity.

GlcNAcstatin: a picomolar, selective O-GlcNAcase inhibitor that modulates intracellular O-glcNAcylation levels.[Pubmed:17177381]

J Am Chem Soc. 2006 Dec 27;128(51):16484-5.

Many phosphorylation signal transduction pathways in the eukaryotic cell are modulated by posttranslational modification of specific serines/threonines with N-acetylglucosamine (O-GlcNAc). Levels of O-GlcNAc on key proteins regulate biological processes as diverse as the cell cycle, insulin signaling, and protein degradation. The two enzymes involved in this dynamic and abundant modification are the O-GlcNAc transferase and O-GlcNAcase. Structural data have recently revealed that the O-GlcNAcase possesses an active site with significant structural similarity to that of the human lysosomal hexosaminidases HexA/HexB. PUGNAc, an O-GlcNAcase inhibitor widely used to raise levels of O-GlcNAc in human cell lines, also inhibits these hexosaminidases. Here, we have exploited recent structural information of an O-GlcNAcase-PUGNAc complex to design and synthesize a glucoimidazole-based inhibitor, GlcNAcstatin, which is a 5 pM competitive inhibitor of enzymes of the O-GlcNAcase family, shows 100000-fold selectivity over HexA/B, and binds to the O-GlcNAcase active site by mimicking the transition state as revealed by X-ray crystallography. This compound is able to raise O-GlcNAc levels in human HEK 293 and SH-SY5Y neuroblastoma cell lines and thus provides a novel, potent tool for the study of the role of O-GlcNAc in intracellular signal transduction pathways.