scholarly journals Redox analysis of the cytochrome o-type quinol oxidase complex of Escherichia coli reveals three redox components

1991 ◽  
Vol 274 (3) ◽  
pp. 723-730 ◽  
Author(s):  
B Bolgiano ◽  
I Salmon ◽  
W J Ingledew ◽  
R K Poole
Keyword(s):  
Escherichia Coli ◽  
Soret Band ◽  
Oxygen Binding ◽  
Quinol Oxidase ◽  
E Coli ◽  
Cytochrome Bo ◽  
Twin Peaks ◽  
Cytochrome O ◽  
Potential Component ◽  
Maximal Peak

Potentiometric analyses of the cytochrome o-type oxidase of Escherichia coli, using membranes from a strain containing amplified levels of the cytochrome bo complex, were conducted to resolve the redox centres of the oxidase. The cytochrome o-type oxidase of E. coli, a quinol oxidase, contains 2 mol of b-type haem per mol of complex and copper. Detailed analysis of potentiometric titrations, based on the absorbance of the Soret band, suggests that there are three contributions with midpoint potentials (Em,7) around +55 mV, +211 mV and +408 mV, all with maxima at 426-430 nm in the reduced state. In the alpha region of the spectra, a component with Em,6.85 = +58 mV has a maximal peak at 557 nm, and twin peaks at 556 and 564 nm nitrate with Em,6.85 = +227 mV. A feature corresponding to the highest potential Soret contribution was not observed. These data can be explained either by a model incorporating haem-haem interaction or by attributing the shorter-wavelength band (557 nm) to haem b and a split alpha-band (556, 564 nm) to the haem o (oxygen-binding haem b). Absolute spectra of oxidized membranes show continuous absorbance from 460 to 530 nm and suggest the presence of a high-spin haem component in the membranes. Monitoring absorbance at 635 minus 672 nm, contributions with midpoints (Em,7) around +52 mV, +234 mV and +371 mV are observed. This latter contribution is possibly the highest-potential component which titrates with Em greater than +400 mV in the Soret region and may represent copper-haem coupling in the cytochrome o complex.

scholarly journals Heme-copper and heme-heme interactions in the cytochrome bo-containing quinol oxidase of Escherichia coli.

1990 ◽  
Vol 265 (8) ◽  
pp. 4364-4368 ◽  
Author(s):  
J C Salerno ◽  
B Bolgiano ◽  
R K Poole ◽  
R B Gennis ◽  
W J Ingledew
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
Cytochrome Bo

scholarly journals A factor produced by Escherichia coli K-12 inhibits the growth of E. coli mutants defective in the cytochrome bd quinol oxidase complex: enterochelin rediscovered

Microbiology ◽  
1998 ◽  
Vol 144 (12) ◽  
pp. 3297-3308 ◽  
Author(s):  
G. M. Cook ◽  
C. Loder ◽  
B. Soballe ◽  
G. P. Stafford ◽  
J. Membrillo-Hernandez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
E Coli ◽  
Cytochrome Bd ◽  
K 12

scholarly journals Prosthetic groups of the NADH-dependent nitrite reductase from Escherichia coli K12

1981 ◽  
Vol 193 (3) ◽  
pp. 861-867 ◽  
Author(s):  
R H Jackson ◽  
A Cornish-Bowden ◽  
J A Cole
Keyword(s):  
Escherichia Coli ◽  
Nitrite Reductase ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Soret Band ◽  
Horse Heart Cytochrome ◽  
E Coli ◽  
Highly Active ◽  
Covalently Bound

A substantially improved purification of Escherichia coli NADH-dependent nitrite reductase was obtained by purifying it in presence of 1 mM-NO2- and 10 microM-FAD. The enzyme was obtained in 20% yield with a maximum specific activity of 1.04 kat . kg-1: more than 95% of this sample subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis migrated as a single band of protein. This highly active enzyme contained one non-covalently bound FAD molecule, and, probably, 5 Fe atoms and 4 acid-labile S atoms per subunit. No FMN, covalently bound flavin or Mo was detected. The spectrum of the enzyme shows absorption maxima at 386, 455, 530 and about 575 nm with a shoulder at 480–490 nm. The Soret-band/alpha-band absorbance ratio is about 4:1. These spectral features are characteristic of sirohaem, apart from the maximum at 455nm, which is attributed to flavin. The enzyme also catalyses the NADH-dependent reduction of horse heart cytochrome c, 2,6-dichlorophenol-indophenol and K3Fe(CN)6. The presence of sirohaem in E. coli nitrite reductase explains the apparent identity of the cysG and nirB gene of E. coli and inability of hemA mutants to reduce nitrite.

Studies on a Stabilisation of Ubisemiquinone by Escherichia coli Quinol Oxidase, Cytochrome bo

1995 ◽  
Vol 227 (3) ◽  
pp. 903-908 ◽  
Author(s):  
W. John Ingledew ◽  
Tomoko Ohnishi ◽  
John C. Salerno
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
Cytochrome Bo

scholarly journals Expressed Soybean Leghemoglobin: Effect on Escherichia coli at Oxidative and Nitrosative Stress

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7207
Author(s):  
Olga V. Kosmachevskaya ◽  
Elvira I. Nasybullina ◽  
Konstantin B. Shumaev ◽  
Alexey F. Topunov
Keyword(s):  
Escherichia Coli ◽  
Energy Demand ◽  
Nitrosative Stress ◽  
Electron Paramagnetic Resonance Spectroscopy ◽  
Model Systems ◽  
Resonance Spectroscopy ◽  
Oxygen Binding ◽  
Oxidative And Nitrosative Stress ◽  
E Coli ◽  
Soybean Leghemoglobin

Leghemoglobin (Lb) is an oxygen-binding plant hemoglobin of legume nodules, which participates in the symbiotic nitrogen fixation process. Another way to obtain Lb is its expression in bacteria, yeasts, or other organisms. This is promising for both obtaining Lb in the necessary quantity and scrutinizing it in model systems, e.g., its interaction with reactive oxygen (ROS) and nitrogen (RNS) species. The main goal of the work was to study how Lb expression affected the ability of Escherichia coli cells to tolerate oxidative and nitrosative stress. The bacterium E. coli with the embedded gene of soybean leghemoglobin a contains this protein in an active oxygenated state. The interaction of the expressed Lb with oxidative and nitrosative stress inducers (nitrosoglutathione, tert-butyl hydroperoxide, and benzylviologen) was studied by enzymatic methods and spectrophotometry. Lb formed NO complexes with heme-nitrosylLb or nonheme iron-dinitrosyl iron complexes (DNICs). The formation of Lb-bound DNICs was also detected by low-temperature electron paramagnetic resonance spectroscopy. Lb displayed peroxidase activity and catalyzed the reduction of organic peroxides. Despite this, E. coli-synthesized Lb were more sensitive to stress inducers. This might be due to the energy demand required by the Lb synthesis, as an alien protein consumes bacterial resources and thereby decreases adaptive potential of E. coli.

scholarly journals Cytochrome bd promotes Escherichia coli biofilm antibiotic tolerance by regulating accumulation of noxious chemicals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Connor J. Beebout ◽  
Levy A. Sominsky ◽  
Allison R. Eberly ◽  
Gerald T. Van Horn ◽  
Maria Hadjifrangiskou
Keyword(s):  
Escherichia Coli ◽  
Quinol Oxidase ◽  
E Coli ◽  
Cytochrome Bd ◽  
External Agents ◽  
Specific Increase ◽  
Matrix Production ◽  
Noxious Chemicals ◽  
Biofilm Development ◽  
Outer Membrane Permeability

AbstractNutrient gradients in biofilms cause bacteria to organize into metabolically versatile communities capable of withstanding threats from external agents including bacteriophages, phagocytes, and antibiotics. We previously determined that oxygen availability spatially organizes respiration in uropathogenic Escherichia coli biofilms, and that the high-affinity respiratory quinol oxidase cytochrome bd is necessary for extracellular matrix production and biofilm development. In this study we investigate the physiologic consequences of cytochrome bd deficiency in biofilms and determine that loss of cytochrome bd induces a biofilm-specific increase in expression of general diffusion porins, leading to elevated outer membrane permeability. In addition, loss of cytochrome bd impedes the proton mediated efflux of noxious chemicals by diminishing respiratory flux. As a result, loss of cytochrome bd enhances cellular accumulation of noxious chemicals and increases biofilm susceptibility to antibiotics. These results identify an undescribed link between E. coli biofilm respiration and stress tolerance, while suggesting the possibility of inhibiting cytochrome bd as an antibiofilm therapeutic approach.

scholarly journals ACTION SPECTRA FOR PHOTOREACTIVATION OF ULTRAVIOLET-IRRADIATED ESCHERICHIA COLI AND STREPTOMYCES GRISEUS

1951 ◽  
Vol 34 (6) ◽  
pp. 835-852 ◽  
Author(s):  
Albert Kelner
Keyword(s):  
Escherichia Coli ◽  
Wave Length ◽  
Action Spectrum ◽  
Streptomyces Griseus ◽  
Soret Band ◽  
E Coli ◽  
Action Spectra ◽  
Effective Wave ◽  
Active Wave ◽  
Escherichia Coli B

Action spectra for photoreactivation (light-induced recovery from ultraviolet radiation injury) of Escherichia coli B/r and Streptomyces griseus ATCC 3326 were determined. The spectral region explored was 365 to 700 mµ. The action spectrum for S. griseus differed from that for E. coli, indicating that the chromophores absorbing reactivating energy in the two species were not the same. Reactivation of S. griseus occurred in the region 365 mµ (the shortest wave length studied) to about 500 mµ, with the most effective wave length lying near 436 mµ. This single sharp peak in the spectrum at 436 mµ suggested the Soret band typical of porphyrins. Reactivation of E. coli occurred in the region 365 to about 470 mµ, with the most active wave length lying near 375 mµ. The single, non-pronounced peak near 375 was probably not due to a Soret band, and the identification of the substance absorbing reactivating light in E. coli is uncertain. In neither species was the region 500 to 700 mµ active. The implications of these action spectra and their differences are discussed.

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