Characterization of a soluble oxidoreductase from the thermophilic bacterium Carboxydothermus ferrireducens.
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.
Onyenwoke
Rob Uche
RU
Department of Microbiology, The University of Georgia, Athens, 30602, USA. onyenwok@email.unc.edu
Geyer
R
R
Wiegel
Juergen
J
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
D005420:Flavoproteins; D011809:Quinones; D009243:NAD; D009249:NADP; D007501:Iron; D010088:Oxidoreductases; D010100:Oxygen