Biochemical and spectroscopic studies of the electronic structure and reactivity of a methyl-Ni species formed on methyl-coenzyme M reductase

Mishtu Dey, Joshua Telser, Ryan C. Kunz, Nicholas S. Lees, Stephen W. Ragsdale, Brian M. Hoffman*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

49 Scopus citations

Abstract

The enzyme methyl coenzyme M reductase (MCR) catalyzes the final step of methane production by methanogenic organisms. The active site contains a Ni-macrocyclic complex, F430, in which the Ni is in the 1+ oxidation state in the active form, MCRred1. We describe the preparation and spectroscopic characterization of a Ni-methyl species, denoted MCRMe, generated from MCRred1 by reaction with CH3I. EPR and 13C, 1,2H pulsed ENDOR spectra of methyl isotopologues (CH3, CD3, 13CH3) umambiguously establish the presence of CH3-Ni(III) moiety. They explain why both MCRred1 and MCRMe have dx2-y2 odd-electrons although formally having Ni(I) in the former and Ni(III) in the latter. The simple MO description further gives a simple explanation to the small transfer of spin density (-1%) from Ni to methyl. The MCRME species undergoes conversion to methane and to methyl-SCoM, indicating its catalytic competence as an intermediate in methanogenesis.

Original languageEnglish (US)
Pages (from-to)11030-11032
Number of pages3
JournalJournal of the American Chemical Society
Volume129
Issue number36
DOIs
StatePublished - Sep 12 2007

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'Biochemical and spectroscopic studies of the electronic structure and reactivity of a methyl-Ni species formed on methyl-coenzyme M reductase'. Together they form a unique fingerprint.

Cite this