title: Catalytic properties of Na+-translocating NADH:quinone oxidoreductases from Vibrio harveyi, Klebsiella pneumoniae, and Azotobacter vinelandii.
abstract: The catalytic properties of sodium-translocating NADH:quinone oxidoreductases (Na+-NQRs) from the marine bacterium Vibrio harveyi, the enterobacterium Klebsiella pneumoniae, and the soil microorganism Azotobacter vinelandii have been comparatively analyzed. It is shown that these enzymes drastically differ in their affinity to sodium ions. The enzymes also possess different sensitivity to inhibitors. Na+-NQR from A. vinelandii is not sensitive to low 2-n-heptyl-4-hydroxyquinoline N-oxide (HQNO) concentrations, while Na+-NQR from K. pneumoniae is fully resistant to either Ag+ or N-ethylmaleimide. All the Na+-NQR-type enzymes are sensitive to diphenyliodonium, which is shown to modify the noncovalently bound FAD of the enzyme.
authors.affiliation: Department of Molecular Energetics of Microorganisms, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia.
authors.forename: Maria S
authors.initials: MS
authors.lastname: Fadeeva
authors.forename: Cinthia
authors.initials: C
authors.lastname: Núñez
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Bertsova
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Espín
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Bogachev
mesh_terms: D016948:Azotobacter vinelandii / Q000201:enzymology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001713:Biphenyl Compounds / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006912:Hydroxyquinolines / Q000494:pharmacology; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D009861:Onium Compounds / Q000494:pharmacology; D011808:Quinone Reductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012834:Silver / Q000494:pharmacology; D014733:Vibrio / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D006912:Hydroxyquinolines; D009861:Onium Compounds; C031291:diphenyliodonium; C001333:2-(n-heptyl)-4-hydroxyquinoline N-oxide; D012834:Silver; C084142:sodium-translocating NADH-quinone reductase; D011808:Quinone Reductases; D005033:Ethylmaleimide