Forte 2016 Sci Rep: Difference between revisions
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|abstract=Hydrogen sulfide (H<sub>2</sub>S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including ''Escherichia (E.) coli'', generate H<sub>2</sub>S and encounter high H<sub>2</sub>S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O<sub>2</sub>-dependent respiration. ''E. coli'' has three respiratory oxidases, the cyanide-sensitive heme-copper bo<sub>3</sub> enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo<sub>3</sub> oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC<sub>50</sub>β=β1.1βΒ±β0.1βΞΌM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58βΞΌM. In ''E. coli'' respiratory mutants, both O<sub>2</sub>-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo<sub>3</sub> oxidase alone, but unaffected by β€200βΞΌM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type ''E. coli'' showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O<sub>2</sub>-consumption and growth in ''E. coli'' and possibly other bacteria. The impact of this discovery is discussed. | |abstract=Hydrogen sulfide (H<sub>2</sub>S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including ''Escherichia (E.) coli'', generate H<sub>2</sub>S and encounter high H<sub>2</sub>S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O<sub>2</sub>-dependent respiration. ''E. coli'' has three respiratory oxidases, the cyanide-sensitive heme-copper bo<sub>3</sub> enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo<sub>3</sub> oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC<sub>50</sub>β=β1.1βΒ±β0.1βΞΌM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58βΞΌM. In ''E. coli'' respiratory mutants, both O<sub>2</sub>-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo<sub>3</sub> oxidase alone, but unaffected by β€200βΞΌM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type ''E. coli'' showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O<sub>2</sub>-consumption and growth in ''E. coli'' and possibly other bacteria. The impact of this discovery is discussed. | ||
|mipnetlab=IT | |mipnetlab=IT Rome Sarti P | ||
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Latest revision as of 11:19, 21 January 2020
Forte E, Borisov VB, Falabella M, Colaço HG, Tinajero-Trejo M, Poole RK, Vicente JB, Sarti P, Giuffrè A (2016) The terminal oxidase cytochrome bd promotes sulfide-resistant bacterial respiration and growth. Sci Rep 6:23788. |
Forte E, Borisov VB, Falabella M, Colaco HG, Tinajero-Trejo M, Poole RK, Vicente JB, Sarti P, Giuffre A (2016) Sci Rep
Abstract: Hydrogen sulfide (H2S) impairs mitochondrial respiration by potently inhibiting the heme-copper cytochrome c oxidase. Since many prokaryotes, including Escherichia (E.) coli, generate H2S and encounter high H2S levels particularly in the human gut, herein we tested whether bacteria can sustain sulfide-resistant O2-dependent respiration. E. coli has three respiratory oxidases, the cyanide-sensitive heme-copper bo3 enzyme and two bd oxidases much less sensitive to cyanide. Working on the isolated enzymes, we found that, whereas the bo3 oxidase is inhibited by sulfide with half-maximal inhibitory concentration IC50β=β1.1βΒ±β0.1βΞΌM, under identical experimental conditions both bd oxidases are insensitive to sulfide up to 58βΞΌM. In E. coli respiratory mutants, both O2-consumption and aerobic growth proved to be severely impaired by sulfide when respiration was sustained by the bo3 oxidase alone, but unaffected by β€200βΞΌM sulfide when either bd enzyme acted as the only terminal oxidase. Accordingly, wild-type E. coli showed sulfide-insensitive respiration and growth under conditions favouring the expression of bd oxidases. In all tested conditions, cyanide mimicked the functional effect of sulfide on bacterial respiration. We conclude that bd oxidases promote sulfide-resistant O2-consumption and growth in E. coli and possibly other bacteria. The impact of this discovery is discussed.
β’ O2k-Network Lab: IT Rome Sarti P
Labels: MiParea: Respiration, Pharmacology;toxicology
Organism: Eubacteria
Preparation: Enzyme, Oxidase;biochemical oxidation
HRR: Oxygraph-2k
2016-06