The Respiratory Chain of Anaerobically Grown Escherichia coli: Reactions with Nitrite and Oxygen
| Autor: | Houston Am, Ingledew Wj, Rothery Ra |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
Hemeprotein
Kinetics Respiratory chain chemistry.chemical_element medicine.disease_cause Photochemistry Microbiology Oxygen Electron Transport Cytochrome d Group chemistry.chemical_compound Escherichia coli medicine Anaerobiosis Nitrite Nitrites Oxidase test Spectrum Analysis Cytochrome d NADPH Oxidases Hydrogen-Ion Concentration Cytochrome b Group chemistry Cytochromes |
| Zdroj: | Microbiology. 133:3247-3255 |
| ISSN: | 1465-2080 1350-0872 |
| DOI: | 10.1099/00221287-133-11-3247 |
| Popis: | SUMMARY: The reactions of nitrite and oxygen with the cytochrome d oxidase of Escherichia coli were studied, following growth of cells on glycerol with fumarate as respiratory oxidant. Optical difference spectroscopy was used to investigate the kinetics of product formation during the reaction of the respiratory chain with nitrite. Two kinetically distinct species were formed in the reaction with nitrite; these had spectral features at 438 nm and 630 nm. These observations indicate that the cytochrome d does not contribute significantly to absorbance in the Soret region, and that changes elicited by ligand binding in the Soret region are largely attributable to haemoprotein b-590. Inhibition of respiratory oxidase activity by nitrite was also investigated. The inhibition was competitive with oxygen (K i 0·83 mm, pH 7), which allowed analysis of the reaction of the oxidase with oxygen itself. The reaction with oxygen was cooperative with an apparent number of oxygen-binding sites, n, of 1·26 at pH 7, increasing to 1·72 at pH 6. We propose a model for the oxidase in which there are two ligand-binding sites. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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