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DFT study of the mechanism for methane hydroxylation by soluble methane monooxygenase (sMMO): effects of oxidation state, spin state, and coordination number

DFT study of the mechanism for methane hydroxylation by soluble methane monooxygenase (sMMO): effects of oxidation state, spin state, and coordination number

Authors :
Shuping Huang
Kazunari Yoshizawa
Yoshihito Shiota
Source :
Dalton Trans.. 42:1011-1023
Publication Year :
2013
Publisher :
Royal Society of Chemistry (RSC), 2013.

Abstract

The exact structure of the active site of intermediate Q, the methane-oxidizing species of soluble methane monooxygenase (sMMO), and the reaction mechanism of Q with methane molecule are still not fully clear. To gain further insights into the structure and reaction mechanism, five diiron models of Q that differ in shape, oxidation state, spin state, and coordination number of the two iron centers are studied. Different mechanisms in different spin states were explored. Density functional theory (DFT) calculations show that Fe(III)Fe(IV)(μ-O)(μ-OH) is more reactive than Fe(IV)(2)(μ-O)(2) in the oxygen-rich environment and that the reactivity of the active core of sMMO-Q is not enhanced by converting its oxo bridge into a terminal ligand. A four-coordinated diiron model is the most effective for methane hydroxylation. Both radical and non-radical intermediates are involved in the reactions for the four-coordinated diiron model.

Details

ISSN :
14779234 and 14779226
Volume :
42
Database :
OpenAIRE
Journal :
Dalton Trans.
Accession number :
edsair.doi.dedup.....ccf7a712dbddd40ef35a805d4d2d7a5d
Full Text :
https://doi.org/10.1039/c2dt31304a