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Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition
Published on: October 3, 2018
Anaerobic microbes: oxygen detoxification without superoxide dismutase
F E Jenney1, M F Verhagen, X Cui
1Department of Biochemistry and Molecular Biology, Center for Metalloenzyme Studies, University of Georgia, Athens, GA 30602-7229, USA.
Science (New York, N.Y.)
|October 9, 1999
Summary
Superoxide reductase (SOR) in Pyrococcus furiosus reduces toxic superoxide to hydrogen peroxide, offering a survival advantage to anaerobes. This enzyme functions effectively even at temperatures significantly below the organism's optimal growth.
Area of Science:
- Biochemistry
- Microbiology
- Enzymology
Background:
- Hyperthermophilic anaerobes like Pyrococcus furiosus face potential oxygen exposure.
- Superoxide is a toxic reactive oxygen species.
- Aerobes use superoxide dismutase (SOD) to detoxify superoxide, producing oxygen.
Purpose of the Study:
- To investigate the function of superoxide reductase (SOR) in Pyrococcus furiosus.
- To understand how this enzyme contributes to the survival of anaerobes in the presence of oxygen.
Main Methods:
- Enzyme activity assays for superoxide reductase.
- Investigated electron transfer pathway involving reduced nicotinamide adenine dinucleotide phosphate, rubredoxin, and an oxidoreductase.
- Assessed enzyme function at various temperatures relative to optimal growth.
Main Results:
- Superoxide reductase (SOR) reduces superoxide to hydrogen peroxide using electrons from NADPH via rubredoxin and an oxidoreductase.
- Peroxidases further reduce hydrogen peroxide to water.
- SOR is catalytically active at 80°C below the optimal growth temperature of P. furiosus (100°C).
Conclusions:
- SOR provides a selective advantage to anaerobes by detoxifying superoxide without producing oxygen.
- The enzyme's activity at lower temperatures ensures protection under conditions where P. furiosus might encounter oxygen.
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