Enzymatic Removal of Nitric Oxide Catalyzed by Cytochrome c ′ in Rhodobacter capsulatus
Open Access
- 15 May 2001
- journal article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 183 (10) , 3050-3054
- https://doi.org/10.1128/jb.183.10.3050-3054.2001
Abstract
Cytochrome c′ from Rhodobacter capsulatushas been shown to confer resistance to nitric oxide (NO). In this study, we demonstrated that the amount of cytochrome c′ synthesized for buffering of NO is insufficient to account for the resistance to NO but that the cytochrome-dependent resistance mechanism involves the catalytic breakdown of NO, under aerobic and anaerobic conditions. Even under aerobic conditions, the NO removal is independent of molecular oxygen, suggesting cytochrome c′ is a NO reductase. Indeed, we have measured the product of NO breakdown to be nitrous oxide (N2O), thus showing that cytochromec′ is behaving as a NO reductase. The increased resistance to NO conferred by cytochrome c′ is distinct from the NO reductase pathway that is involved in denitrification. Cytochromec′ is not required for denitrification, but it has a role in the removal of externally supplied NO. Cytochrome c′ synthesis occurs aerobically and anaerobically but is partly repressed under denitrifying growth conditions when other NO removal systems are operative. The inhibition of respiratory oxidase activity of R. capsulatus by NO suggests that one role for cytochromec′ is to maintain oxidase activity when both NO and O2 are present.Keywords
This publication has 18 references indexed in Scilit:
- Flavohemoglobin Hmp Affords Inducible Protection for Escherichia coli Respiration, Catalyzed by Cytochromesbo′ or bd, from Nitric OxideJournal of Biological Chemistry, 2000
- A membrane-inlet mass spectrometer miniprobe for the direct simultaneous measurement of multiple gas species with spatial resolution of 1 mmJournal of Microbiological Methods, 1996
- Nanomolar concentrations of nitric oxide reversibly inhibit synaptosomal respiration by competing with oxygen at cytochrome oxidaseFEBS Letters, 1994
- An unusual hemoprotein capable of reversible binding of nitric oxide from the gram-positive Bacillus halodenitrificansArchiv für Mikrobiologie, 1994
- A denitrifying strain ofRhodobacter capsulatusFEMS Microbiology Letters, 1994
- Five coordinated nitrosylhemoprotein in the whole cells of denitrifying bacterium, Achromobacter xylosoxidans NCIB 11015Archiv für Mikrobiologie, 1993
- Identification of nitric oxide reductase activity in Rhodobacter capsulatus: the electron transport pathway can either use or bypass both cytochrome c2 and the cytochrome bc1 complexJournal of General Microbiology, 1992
- Effect of aerobic growth conditions on the soluble cytochrome content of the purple phototrophic bacterium Rhodobacter sphaeroides: Induction of cytochrome c554Archives of Biochemistry and Biophysics, 1989
- Spectral properties of cytochrome c′ from Rhodopseudomonas capsulata B100 and its CO complexBiochemical and Biophysical Research Communications, 1987
- New Perspectives on c-Type CytochromesAdvances in Protein Chemistry, 1982