title: Identification of iron(III) peroxo species in the active site of the superoxide reductase SOR from Desulfoarculus baarsii.
abstract: The active site of superoxide reductase SOR consists of an Fe2+ center in an unusual [His4 Cys1] square-pyramidal geometry. It specifically reduces superoxide to produce H2O2. Here, we have reacted the SOR from Desulfoarculus baarsii directly with H2O2. We have found that its active site can transiently stabilize an Fe3+-peroxo species that we have spectroscopically characterized by resonance Raman. The mutation of the strictly conserved Glu47 into alanine results in a stabilization of this Fe3+-peroxo species, when compared to the wild-type form. These data support the hypothesis that the reaction of SOR proceeds through such a Fe3+-peroxo intermediate. This also suggests that Glu47 might serve to help H2O2 release during the reaction with superoxide.
authors: Laboratoire de Biophysique du Stress Oxydant, SBE/DBJC CEA/SACLAY, 91191 Gif-sur-Yvette Cedex, France.
authors: Christelle
authors: C
authors: Mathé
authors: Tony A
authors: TA
authors: Mattioli
authors: Olivier
authors: O
authors: Horner
authors: Murielle
authors: M
authors: Lombard
authors: Jean-Marc
authors: JM
authors: Latour
authors: Marc
authors: M
authors: Fontecave
authors: Vincent
authors: V
authors: Nivière
mesh_terms: D001665:Binding Sites; D020564:Deltaproteobacteria / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: D005290:Ferric Compounds; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C121849:superoxide reductase