X-ray crystal structure of arsenite-inhibited xanthine oxidase: μ-sulfido,μ-oxo double bridge between molybdenum and arsenic in the active site.

ABSTRACT: Xanthine oxidoreductase is a molybdenum-containing enzyme that catalyzes the hydroxylation reaction of sp(2)-hybridized carbon centers of a variety of substrates, including purines, aldehydes, and other heterocyclic compounds. The complex of arsenite-inhibited xanthine oxidase has been characterized previously by UV-vis, electron paramagnetic resonance, and X-ray absorption spectroscopy (XAS), and the catalytically essential sulfido ligand of the square-pyrimidal molybdenum center has been suggested to be involved in arsenite binding through either a μ-sulfido,μ-oxo double bridge or a single μ-sulfido bridge. However, this is contrary to the crystallographically observed single μ-oxo bridge between molybdenum and arsenic in the desulfo form of aldehyde oxidoreductase from Desulfovibrio gig

SUBMITTER: Cao H 

PROVIDER: S-EPMC3163118 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature