title: Biochemical and spectroscopic characterization of an aldehyde oxidoreductase isolated from Desulfovibrio aminophilus.
abstract: Aldehyde oxidoreductase (AOR) activity has been found in a number of sulfate-reducing bacteria. The enzyme that is responsible for the conversion of aldehydes to carboxylic acids is a mononuclear molybdenum enzyme belonging to the xanthine oxidase family. We report here the purification and characterization of AOR isolated from the sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254, an aminolytic strain performing thiosulfate dismutation. The enzyme is a homodimer (ca. 200 kDa), containing a molybdenum centre and two [2Fe-2S] clusters per monomer. UV/Visible and electron paramagnetic resonance (EPR) spectra of D. aminophilus AOR recorded in as-prepared and reduced states are similar to those obtained in AORs from Desulfovibrio gigas, Desulfovibrio desulfuricans and Desulfovibrio alaskensis. Despite AOR from D. aminophilus is closely related to other AORs, it presents lower activity towards aldehydes and no activity towards N-heterocyclic compounds, which suggests another possible role for this enzyme in vivo. A comparison of the molecular and EPR properties of AORs from different Desulfovibrio species is also included.
authors.affiliation: REQUIMTE, Departamento de Química, Centro de Química Fina e Biotecnologia, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Monte de Caparica, Portugal.
authors.forename: Anders
authors.initials: A
authors.lastname: Thapper
authors.forename: Maria G
authors.initials: MG
authors.lastname: Rivas
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Brondino
authors.forename: Bernard
authors.initials: B
authors.lastname: Ollivier
authors.forename: Guy
authors.initials: G
authors.lastname: Fauque
authors.forename: Isabel
authors.initials: I
authors.lastname: Moura
authors.forename: José J G
authors.initials: JJ
authors.lastname: Moura
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000737:chemistry*; D003067:Coenzymes / Q000737:chemistry; D003901:Desulfovibrio / Q000737:chemistry / Q000201:enzymology*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D007506:Iron-Sulfur Proteins / Q000737:chemistry; D007700:Kinetics; D008667:Metalloproteins / Q000737:chemistry; D008970:Molecular Weight; D000090006:Molybdenum Cofactors; D010084:Oxidation-Reduction; D011621:Pteridines / Q000737:chemistry; D013045:Species Specificity; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000445:Aldehyde Oxidoreductases; D003067:Coenzymes; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D000090006:Molybdenum Cofactors; D011621:Pteridines; C022261:molybdopterin