title: Characterization of a soluble oxidoreductase from the thermophilic bacterium Carboxydothermus ferrireducens.
abstract: An NAD(P)H-dependent oxidoreductase has been purified approximately 40-fold from the soluble protein fraction of the dissimilatory iron-reducing, anaerobic, thermophilic bacterium Carboxydothermus ferrireducens. The enzyme, a flavoprotein, has broad-substrate specificity-reducing Fe(3+), Cr(6+), and AQDS with rates of 0.31, 0.33, and 3.3 U mg(-1) protein and calculated NADH oxidation turnover numbers of 0.25, 0.25, and 2.5 s(-1), respectively. Numerous quinones are reduced via a two-electron transfer from NAD(P)H to quinone, thus participating in managing oxidative stress by avoiding the formation of semiquinone radicals.
authors.affiliation: Department of Microbiology, The University of Georgia, Athens, 30602, USA. onyenwok@email.unc.edu
authors.forename: Rob Uche
authors.initials: RU
authors.lastname: Onyenwoke
authors.forename: R
authors.initials: R
authors.lastname: Geyer
authors.forename: Juergen
authors.initials: J
authors.lastname: Wiegel
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology*; D005420:Flavoproteins / Q000737:chemistry; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D009243:NAD / Q000737:chemistry; D009249:NADP / Q000378:metabolism; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics*; D010100:Oxygen / Q000737:chemistry; D011809:Quinones / Q000737:chemistry; D012995:Solubility; D013379:Substrate Specificity
chemical_list: D005420:Flavoproteins; D011809:Quinones; D009243:NAD; D009249:NADP; D007501:Iron; D010088:Oxidoreductases; D010100:Oxygen