Nitrogenase inactivation by oxygen and enzyme turnover in Anabaena cylindrica
| Autor: | Marcia A. Murry, Patrick C. Hallenbeck, John R. Benemann, Diane Esteva |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Cyanobacteria
chemistry.chemical_classification biology Anabaena Immunology chemistry.chemical_element Nitrogenase General Medicine Biodegradation biology.organism_classification Applied Microbiology and Biotechnology Microbiology Oxygen Enzyme chemistry Biochemistry In vivo Genetics Microaerophile Molecular Biology |
| Zdroj: | Canadian Journal of Microbiology. 29:1286-1294 |
| ISSN: | 1480-3275 0008-4166 |
| DOI: | 10.1139/m83-201 |
| Popis: | Nitrogenase is known to be irreversibly inactivated by oxygen in vivo and in vitro. In time-course experiments using Anabaena cylindrica, cultures treated with antibiotics and incubated under various O2 tensions, in vivo acetylene reduction activity and immunologically determined Fe–Mo protein (component I) were lost at rates directly related to O2 tension. Activity was lost at a faster rate than cross-reactive material. The half-life of cross-reactive material was 25 h under microaerophilic conditions, 12 h under aerobic conditions, and 6.6 h under an O2 tension of 245% of air saturation. In vitro, cross-reactive material was lost in O2 exposed, but not in anaerobically prepared, crude cell extracts. Loss of cross-reactive material was prevented by freezing and by α-N-tosyl-L-phenylalanine chloromethyl ketone (TPCK), an inhibitor of histidine-residue proteases. These results indicate that nitrogenase is continuously inactivated by O2, hydrolyzed, and resynthesized during growth of this heterocystous cyanobacteria under aerobic conditions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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