Vocadlo, D J, Davies, G J orcid.org/0000-0002-7343-776X, Laine, R et al. (1 more author) (2001) Catalysis by hen egg-white lysozyme proceeds via a covalent intermediate. Nature. pp. 835-838. ISSN 0028-0836
Abstract
Hen egg-white lysozyme (HEWL) was the first enzyme to have its three-dimensional structure determined by X-ray diffraction techniques(1). A catalytic mechanism, featuring a long-lived oxo-carbenium-ion intermediate, was proposed on the basis of model-building studies(2). The `Phillips' mechanism is widely held as the paradigm for the catalytic mechanism of beta -glycosidases that cleave glycosidic linkages with net retention of configuration of the anomeric centre. Studies with other retaining beta -glycosidases, however, provide strong evidence pointing to a common mechanism for these enzymes that involves a covalent glycosyl-enzyme intermediate, as previously postulated(3). Here we show, in three different cases using electrospray ionization mass spectrometry, a catalytically competent covalent glycosyl-enzyme intermediate during the catalytic cycle of HEWL. We also show the three-dimensional structure of this intermediate as determined by Xray diffraction. We formulate a general catalytic mechanism for all retaining beta -glycosidases that includes substrate distortion, formation of a covalent intermediate, and the electrophilic migration of C1 along the reaction coordinate.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2001 Nature Publishing Group |
Keywords: | ACTIVE-SITE,BETA-GLUCOSIDASE,LEAVING GROUP,HYDROLYSIS,DISTORTION,MECHANISM,INSIGHTS,MUTANTS,ACID |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Depositing User: | Repository Officer |
Date Deposited: | 13 Oct 2004 |
Last Modified: | 22 Jan 2025 00:03 |
Published Version: | https://doi.org/10.1038/35090602 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1038/35090602 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:131 |