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An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase

The protein microenvironment surrounding the flavin cofactor in flavoenzymes is key to the efficiency and diversity of reactions catalysed by this class of enzymes. X-ray diffraction structures of oxidoreductase flavoenzymes have revealed recurrent features which facilitate catalysis, such as a hydr...

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Autores principales: Golden, Emily, Yu, Li-Juan, Meilleur, Flora, Blakeley, Matthew P., Duff, Anthony P., Karton, Amir, Vrielink, Alice
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241826/
https://www.ncbi.nlm.nih.gov/pubmed/28098177
http://dx.doi.org/10.1038/srep40517
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author Golden, Emily
Yu, Li-Juan
Meilleur, Flora
Blakeley, Matthew P.
Duff, Anthony P.
Karton, Amir
Vrielink, Alice
author_facet Golden, Emily
Yu, Li-Juan
Meilleur, Flora
Blakeley, Matthew P.
Duff, Anthony P.
Karton, Amir
Vrielink, Alice
author_sort Golden, Emily
collection PubMed
description The protein microenvironment surrounding the flavin cofactor in flavoenzymes is key to the efficiency and diversity of reactions catalysed by this class of enzymes. X-ray diffraction structures of oxidoreductase flavoenzymes have revealed recurrent features which facilitate catalysis, such as a hydrogen bond between a main chain nitrogen atom and the flavin redox center (N5). A neutron diffraction study of cholesterol oxidase has revealed an unusual elongated main chain nitrogen to hydrogen bond distance positioning the hydrogen atom towards the flavin N5 reactive center. Investigation of the structural features which could cause such an unusual occurrence revealed a positively charged lysine side chain, conserved in other flavin mediated oxidoreductases, in a second shell away from the FAD cofactor acting to polarize the peptide bond through interaction with the carbonyl oxygen atom. Double-hybrid density functional theory calculations confirm that this electrostatic arrangement affects the N-H bond length in the region of the flavin reactive center. We propose a novel second-order partial-charge interaction network which enables the correct orientation of the hydride receiving orbital of N5. The implications of these observations for flavin mediated redox chemistry are discussed.
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spelling pubmed-52418262017-01-23 An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase Golden, Emily Yu, Li-Juan Meilleur, Flora Blakeley, Matthew P. Duff, Anthony P. Karton, Amir Vrielink, Alice Sci Rep Article The protein microenvironment surrounding the flavin cofactor in flavoenzymes is key to the efficiency and diversity of reactions catalysed by this class of enzymes. X-ray diffraction structures of oxidoreductase flavoenzymes have revealed recurrent features which facilitate catalysis, such as a hydrogen bond between a main chain nitrogen atom and the flavin redox center (N5). A neutron diffraction study of cholesterol oxidase has revealed an unusual elongated main chain nitrogen to hydrogen bond distance positioning the hydrogen atom towards the flavin N5 reactive center. Investigation of the structural features which could cause such an unusual occurrence revealed a positively charged lysine side chain, conserved in other flavin mediated oxidoreductases, in a second shell away from the FAD cofactor acting to polarize the peptide bond through interaction with the carbonyl oxygen atom. Double-hybrid density functional theory calculations confirm that this electrostatic arrangement affects the N-H bond length in the region of the flavin reactive center. We propose a novel second-order partial-charge interaction network which enables the correct orientation of the hydride receiving orbital of N5. The implications of these observations for flavin mediated redox chemistry are discussed. Nature Publishing Group 2017-01-18 /pmc/articles/PMC5241826/ /pubmed/28098177 http://dx.doi.org/10.1038/srep40517 Text en Copyright © 2017, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Golden, Emily
Yu, Li-Juan
Meilleur, Flora
Blakeley, Matthew P.
Duff, Anthony P.
Karton, Amir
Vrielink, Alice
An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title_full An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title_fullStr An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title_full_unstemmed An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title_short An extended N-H bond, driven by a conserved second-order interaction, orients the flavin N5 orbital in cholesterol oxidase
title_sort extended n-h bond, driven by a conserved second-order interaction, orients the flavin n5 orbital in cholesterol oxidase
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5241826/
https://www.ncbi.nlm.nih.gov/pubmed/28098177
http://dx.doi.org/10.1038/srep40517
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