title: Helicobacter pylori disulphide reductases: role in metronidazole reduction.
abstract: Disulphide reductases play an important role in maintaining intracellular redox potential. Three disulphide reductase activities were identified in Helicobacter pylori, which used dithiobis-2-nitrobenzoic acid, glutathione or l-cystine and ferredoxin as substrates. The kinetic parameters of these activities were determined and it was demonstrated that the reductase activities were inhibited by the presence of metronidazole. Substrate competition experiments served to show inhibition of metronidazole reduction by dithiobis-2-nitrobenzoic acid, glutathione and ferredoxin in lysates from metronidazole susceptible and resistant matched pairs of strains. The study demonstrated that the activities of three disulphide reductases were modulated by the presence of metronidazole, and that metronidazole reduction was inhibited by the presence of disulphide reductase substrates.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Biological Science Builiding, Sydney, NSW 2052, Australia.
authors.forename: Nadeem O
authors.initials: NO
authors.lastname: Kaakoush
authors.forename: George L
authors.initials: GL
authors.lastname: Mendz
mesh_terms: D000890:Anti-Infective Agents / Q000378:metabolism* / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D016480:Helicobacter pylori / Q000187:drug effects / Q000201:enzymology*; D006801:Humans; D007700:Kinetics; D008795:Metronidazole / Q000378:metabolism* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D010084:Oxidation-Reduction
chemical_list: D000890:Anti-Infective Agents; D008795:Metronidazole; D009247:NADH, NADPH Oxidoreductases; C014703:disulfide reductase (NADH)