Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Mechanism of the Dinuclear Iron Enzyme p-Aminobenzoate N-oxygenase from Density Functional Calculations
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Number of Authors: 32019 (English)In: ChemCatChem, ISSN 1867-3880, E-ISSN 1867-3899, Vol. 11, no 1, p. 601-613Article in journal (Refereed) Published
Abstract [en]

AurF is a diiron enzyme that utilizes two dioxygen molecules as the oxidant to catalyze the oxidation of p-aminobenzoate to p-nitrobenzoate. Density functional calculations were performed to elucidate the reaction mechanism of this enzyme. Two different models were considered, with the oxygenated intermediate being a diferric peroxo species or a diferric hydroperoxo species. The calculations strongly favor the model with a diferric peroxo species and support the mechanism proposed by Bollinger and co-workers. The reaction starts with the binding of a dioxygen molecule to the diferrous center to generate a diferric peroxide complex. This is followed by the cleavage of the O-O bond, concertedly with the formation of the first N-O bond, which has a barrier of only 9.2kcal/mol. Subsequently, the first-shell ligand Glu227 abstracts a proton from the substrate. After the delivery of two electrons from the external reductant and two protons from solution, a water molecule and the experimentally suggested intermediate p-hydroxylaminobenzoate are produced and the diferrous center is regenerated. The oxidation of the p-hydroxylaminobenzoate intermediate requires the binding of a second dioxygen molecule to the diferrous center to generate the diferric peroxide complex. Similarly to the oxidation of p-aminobenzoate, the O-O bond cleavage and the formation of the second N-O bond take place in a concerted step. The p-nitrobenzoate product is formed after the release of two protons and two electrons from the substrate. The model with a hydroperoxo species gave a much high barrier of 28.7kcal/mol for the substrate oxidation due to the large energy penalty for the generation of the active hydroperoxo species.

Place, publisher, year, edition, pages
2019. Vol. 11, no 1, p. 601-613
Keywords [en]
density functional calculations, enzyme catalysis, reaction mechanism, dinuclear iron enzyme
National Category
Organic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-166595DOI: 10.1002/cctc.201801072ISI: 000457144200053OAI: oai:DiVA.org:su-166595DiVA, id: diva2:1300713
Available from: 2019-03-29 Created: 2019-03-29 Last updated: 2019-03-29Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Siegbahn, Per E. M.
By organisation
Department of Organic Chemistry
In the same journal
ChemCatChem
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf