The radical mechanism of biological methane synthesis by methyl-coenzyme M reductase.
Science
; 352(6288): 953-8, 2016 May 20.
Article
de En
| MEDLINE
| ID: mdl-27199421
ABSTRACT
Methyl-coenzyme M reductase, the rate-limiting enzyme in methanogenesis and anaerobic methane oxidation, is responsible for the biological production of more than 1 billion tons of methane per year. The mechanism of methane synthesis is thought to involve either methyl-nickel(III) or methyl radical/Ni(II)-thiolate intermediates. We employed transient kinetic, spectroscopic, and computational approaches to study the reaction between the active Ni(I) enzyme and substrates. Consistent with the methyl radical-based mechanism, there was no evidence for a methyl-Ni(III) species; furthermore, magnetic circular dichroism spectroscopy identified the Ni(II)-thiolate intermediate. Temperature-dependent transient kinetics also closely matched density functional theory predictions of the methyl radical mechanism. Identifying the key intermediate in methanogenesis provides fundamental insights to develop better catalysts for producing and activating an important fuel and potent greenhouse gas.
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Oxidoreductases
/
Methanobacteriaceae
/
Biocatalyse
/
Méthane
Langue:
En
Journal:
Science
Année:
2016
Type de document:
Article
Pays d'affiliation:
États-Unis d'Amérique