Induction and inactivation of catalase and superoxide dismutase of Escherichia coli by ozone
Oxyradicals have been implicated in ozone (O/sub 3/) toxicity and in other oxidant stress. In this study, we investigated the effects of O/sub 3/ on the biosynthesis of the antioxidant enzymes catalase and superoxide dismutase in Escherichia coli to determine their role in the defense against ozone toxicity. Inhibition of growth and loss of viability were observed in cultures exposed to ozone. Results also showed an increase in the activities of catalase and superoxide dismutase in cultures exposed to ozone, which was shown to be due to true induction rather than activation of preexisting apoproteins. Cessation of O/sub 3/ exposure resulted in 30 min of continual high rate of catalase biosynthesis followed by a gradual decrease in the level of the enzyme approaching that of control cultures. This decrease was attributed to a concomitant cessation of de novo enzyme synthesis and dilution of preexisting enzyme by cellular growth. Ozonation of cell-free extracts showed that superoxide dismutase and catalase are subject to oxidative inactivation by ozone. In vivo induction of these enzymes may represent an adaptive response evolved to protect cells against ozone toxicity.
- Research Organization:
- North Carolina State Univ., Raleigh
- OSTI ID:
- 5833301
- Journal Information:
- Arch. Biochem. Biophys.; (United States), Journal Name: Arch. Biochem. Biophys.; (United States) Vol. 257:2; ISSN ABBIA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL ADAPTATION
BIOLOGICAL FUNCTIONS
CATALASE
ENZYME INDUCTION
ENZYMES
ESCHERICHIA COLI
FUNCTIONS
GENE REGULATION
GROWTH
INHIBITION
KINETICS
MICROORGANISMS
OXIDOREDUCTASES
OZONE
PEROXIDASES
SUPEROXIDE DISMUTASE
TOXICITY