title: Oxidative stress-induced expression of catalases in Comamonas terrigena.
abstract: When grown under oxidative stress, catalatic as well as peroxidatic activity is increased in the Gram-negative bacterium Comamonas terrigena N3H. Two distinct hydroperoxidases were demonstrated by a specific staining. Based on their molar masses and their sensitivity toward 3-amino-1,2,4-triazole and high temperatures, they were identified as dimeric catalase-1 (Cat-1; 150 kDa), and as a tetrameric catalase-2 (Cat-2; 240 kDa) with enhanced peroxidatic activity, respectively. These two catalases differ in their expression during the bacterial growth; whereas the expression of the smaller enzyme (Cat-1) is induced by 0.5 mmol/L peroxides in the medium, and to a lesser degree by 25 mg/L Cd2+, Cat-2 (typical catalase) is almost specifically induced with cadmium ions.
authors.affiliation: Institute of Molecular Biology, Slovak Academy of Sciences, 842 51 Bratislava, Slovakia.
authors.forename: M
authors.initials: M
authors.lastname: Zámocký
authors.forename: B
authors.initials: B
authors.lastname: Polek
authors.forename: J
authors.initials: J
authors.lastname: Godocíková
authors.forename: F
authors.initials: F
authors.lastname: Koller
mesh_terms: D002104:Cadmium / Q000494:pharmacology; D002374:Catalase / Q000235:genetics / Q000378:metabolism*; D020585:Comamonas / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D015964:Gene Expression Regulation, Bacterial; D018384:Oxidative Stress / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D002374:Catalase; D009195:Peroxidase