Bilyard, Matthew K, Bailey, Henry J, Raich, Lluís et al. (8 more authors) (2018) Palladium-mediated enzyme activation suggests multiphase initiation of glycogenesis. Nature. 235–240. ISSN 0028-0836
Abstract
Biosynthesis of glycogen, the essential glucose (and hence energy) storage molecule in humans, animals and fungi1, is initiated by the glycosyltransferase enzyme, glycogenin (GYG). Deficiencies in glycogen formation cause neurodegenerative and metabolic disease2-4, and mouse knockout5 and inherited human mutations6 of GYG impair glycogen synthesis. GYG acts as a 'seed core' for the formation of the glycogen particle by catalysing its own stepwise autoglucosylation to form a covalently bound gluco-oligosaccharide chain at initiation site Tyr 195. Precise mechanistic studies have so far been prevented by an inability to access homogeneous glycoforms of this protein, which unusually acts as both catalyst and substrate. Here we show that unprecedented direct access to different, homogeneously glucosylated states of GYG can be accomplished through a palladium-mediated enzyme activation 'shunt' process using on-protein C-C bond formation. Careful mimicry of GYG intermediates recapitulates catalytic activity at distinct stages, which in turn allows discovery of triphasic kinetics and substrate plasticity in GYG's use of sugar substrates. This reveals a tolerant but 'proof-read' mechanism that underlies the precision of this metabolic process. The present demonstration of direct, chemically controlled access to intermediate states of active enzymes suggests that such ligation-dependent activation could be a powerful tool in the study of mechanism.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018 Springer Nature Limited. All rights reserved. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Pure (York) |
Date Deposited: | 13 Nov 2018 17:20 |
Last Modified: | 06 Jan 2025 00:12 |
Published Version: | https://doi.org/10.1038/s41586-018-0644-7 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1038/s41586-018-0644-7 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:138632 |
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