Structural and mechanistic insights into the electron flow through protein for cytochrome c-tethering copper nitrite reductase

2013 ◽  
Vol 154 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Aiko Tsuda ◽  
Ryosuke Ishikawa ◽  
Hiroyasu Koteishi ◽  
Kosuke Tange ◽  
Yohta Fukuda ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Nitrite Reductase ◽  
Electron Flow ◽  
Flow Through

Sulphide oxidation and oxidative phosphorylation in the mitochondria of the lugworm

1997 ◽  
Vol 200 (1) ◽  
pp. 83-92 ◽  
Author(s):  
S Vökel ◽  
M K Grieshaber
Keyword(s):  
Oxygen Consumption ◽  
Cytochrome C ◽  
Oxidative Phosphorylation ◽  
Cytochrome C Oxidase ◽  
Electron Flow ◽  
Respiratory Control ◽  
Sulphide Oxidation ◽  
Atp Production ◽  
Sulphide Concentration ◽  
Flow Through

Oxygen consumption, ATP production and cytochrome c oxidase activity of isolated mitochondria from body-wall tissue of Arenicola marina were measured as a function of sulphide concentration, and the effect of inhibitors of the respiratory complexes on these processes was determined. Concentrations of sulphide between 6 and 9 µmol l-1 induced oxygen consumption with a respiratory control ratio of 1.7. Production of ATP was stimulated by the addition of sulphide, reaching a maximal value of 67 nmol min-1 mg-1 protein at a sulphide concentration of 8 µmol l-1. Under these conditions, 1 mole of ATP was formed per mole of sulphide consumed. Higher concentrations of sulphide led to a decrease in ATP production until complete inhibition occurred at approximately 50 µmol l-1. The production of ATP with malate and succinate was stimulated by approximately 15 % in the presence of 4 µmol l-1 sulphide, but decreased at sulphide concentrations higher than 15­20 µmol l-1. Cytochrome c oxidase was also inhibited by sulphide, showing half-maximal inhibition at 1.5 µmol l-1 sulphide. Sulphide-induced ATP production was inhibited by antimycin, cyanide and oligomycin but not by rotenone or salicylhydroxamic acid. The present data indicate that sulphide oxidation is coupled to oxidative phosphorylation solely by electron flow through cytochrome c oxidase, whereas the alternative oxidase does not serve as a coupling site. At sulphide concentrations higher than 20 µmol l-1, oxidation of sulphide serves mainly as a detoxification process rather than as a source of energy.

scholarly journals Formation and reduction of a ‘peroxy’ intermediate of cytochrome c oxidase by hydrogen peroxide

1984 ◽  
Vol 217 (3) ◽  
pp. 715-719 ◽  
Author(s):  
J M Wrigglesworth
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Electron Flow ◽  
Soret Band ◽  
Stable Complex ◽  
Direct Reaction ◽  
Alpha Band ◽  
Cyanide Complex ◽  
Absorption Intensity ◽  
Flow Through

In the presence of micromolar concentrations of H2O2, ferric cytochrome c oxidase forms a stable complex characterized by an increased absorption intensity at 606-607 nm with a weaker absorption band in the 560-580 nm region. Higher (millimolar) concentrations of H2O2 result in an enzyme exhibiting a Soret band at 427 nm and an alpha-band of increased intensity in the 589-610 nm region. Addition of H2O2 to ferric cytochrome c oxidase in the presence of cyanide results in absorbance increases at 444nm and 605nm. These changes are not seen if H2O2 is added to the cyanide complex of the ferric enzyme. The results support the idea that direct reaction of H2O2 with ferric cytochrome a 3 produces a ‘peroxy’ intermediate that is susceptible to further reduction by H2O2 at higher peroxide concentrations. Electron flow through cytochrome a is not involved, and the final product of the reaction is the so-called ‘pulsed’ or ‘oxygenated’ ferric form of the enzyme.

scholarly journals The C Termini of Constitutive Nitric-oxide Synthases Control Electron Flow through the Flavin and Heme Domains and Affect Modulation by Calmodulin

2000 ◽  
Vol 275 (38) ◽  
pp. 29225-29232 ◽  
Author(s):  
Linda J. Roman ◽  
Pavel Martásek ◽  
R. Timothy Miller ◽  
Dawn E. Harris ◽  
Melissa A. de la Garza ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Electron Flow ◽  
Nitric Oxide Synthases ◽  
Flow Through

Electron Flow through Geometrical Discontinuity in Coaxial Magnetically Insulated Transmission Lines

2000 ◽  
Vol 39 (Part 1, No. 9A) ◽  
pp. 5280-5286 ◽  
Author(s):  
Kazuki Hiraoka ◽  
Mitsuo Nakajima ◽  
Makoto Shiho ◽  
Kazuhiko Horioka
Keyword(s):  
Transmission Lines ◽  
Electron Flow ◽  
Flow Through ◽  
Geometrical Discontinuity

SINGLE ELECTRON DEVICES

1998 ◽  
Vol 09 (01) ◽  
pp. 165-207 ◽  
Author(s):  
DORAN D. SMITH
Keyword(s):  
Tunnel Junctions ◽  
Electron Flow ◽  
Superconducting Devices ◽  
Time Correlation ◽  
Single Electron ◽  
Net Charge ◽  
Flow Through ◽  
Single Electron Devices ◽  
Electron Devices ◽  
Electron Effects

In the mid 1980s Averin and Likharev predicted that with the use of ultrasmall tunnel junctions a time correlation of electron flow through a junction could be observed, and permit the measurement of the effect of a net charge of less than one electron on the junction. Both effects were soon experimentally verified, and since that time there has been an explosion of work in the filed of single electron devices. This chapter reviews the fundamental concepts behind the operation of such devices. it then describes some of the single electron effects studied in semiconductors. Superconducting devices are then constrasted to the semiconductor and the normal metal single electron devices. The details of some current applications are described, and a thumbnail sketch of current fabrication methods is given.

scholarly journals Correction to Electron Flow through Metalloproteins

2016 ◽  
Vol 116 (14) ◽  
pp. 8313-8313
Author(s):  
Jay R. Winkler ◽  
Harry B. Gray
Keyword(s):  
Electron Flow ◽  
Flow Through

scholarly journals High-Resolution Structural Analysis of a Novel Octaheme Cytochrome c Nitrite Reductase from the Haloalkaliphilic Bacterium Thioalkalivibrio nitratireducens

2009 ◽  
Vol 389 (5) ◽  
pp. 846-862 ◽  
Author(s):  
Konstantin M. Polyakov ◽  
Konstantin M. Boyko ◽  
Tamara V. Tikhonova ◽  
Alvira Slutsky ◽  
Alexey N. Antipov ◽  
...  
Keyword(s):  
Structural Analysis ◽  
High Resolution ◽  
Cytochrome C ◽  
Nitrite Reductase ◽  
Cytochrome C Nitrite Reductase

Purification and Characterization of a Dissimilatory Nitrite Reductase from the Phototrophic Bacterium Rhodopseudomonas palustris

1983 ◽  
Vol 38 (11-12) ◽  
pp. 933-938 ◽  
Author(s):  
Michaela Preuß ◽  
Jobst-Heinrich Klemme
Keyword(s):  
Cytochrome C ◽  
Nitrite Reductase ◽  
Rhodopseudomonas Palustris ◽  
Gel Filtration ◽  
Enzyme Synthesis ◽  
Nitrite Reduction ◽  
Phototrophic Bacterium ◽  
Dissimilatory Nitrite Reductase ◽  
Basic Level

A dissimilatory nitrite reductase from the facultatively phototrophic bacterium , Rhodopseudomonas palustris strain 1a1 was studied. A basic level of the enzyme (10 -50 mU/mg protein) was measured in dark, aerated and anaerobic, photosynthetic cultures. A marked derepression of enzyme synthesis occurred under conditions of oxygen limitation (200-300 mU/mg protein). The addition of nitrite (or nitrate) to the culture medium had only a slight effect on the maximal nitrite reductase titer of cells. The enzyme was purified from photosynthetically grown cells by precipitation with ammonium sulfate, gel filtration through Sepharose 6B and repeated chromatography on DE 52-cellulose. As estimated by gel filtration, the nitrite reductase had a molecular weight of about 120 000 ± 12 000 and yielded only one band (mol. wt. of about 68 000 ± 7000) in SDS-gel electrophoresis. The isoelectric point of the enzyme was at pH 5.1. Nitric oxide (NO) was identified as the reaction product of nitrite reduction. The enzyme also exhibited cytochrome c-oxidase activity and was active with chemically reduced viologen dyes, FMN and cytochrome c as electron donors. Highly purified nitrite reductase preparations contained 10 mol% of a c-type cytochrome. Trace metal analyses indicated the presence of Cu in the enzyme. Consistent with the detection of Cu was the finding that the Cu-chelator, diethyldithiocarbamate, strongly inhibited the nitrite reductase

scholarly journals The effects of acetaldehyde on nitrogenase, hydrogenase and photosynthesis in the cyanobacterium Anabaena cylindrica

1983 ◽  
Vol 212 (3) ◽  
pp. 755-758 ◽  
Author(s):  
B Slatyer ◽  
A Daday ◽  
G D Smith
Keyword(s):  
Methyl Viologen ◽  
Co2 Fixation ◽  
Electron Flow ◽  
Anabaena Cylindrica ◽  
O2 Uptake ◽  
Irreversible Inhibitor ◽  
Photosynthetic Electron Flow ◽  
Separate Electron ◽  
Cyanobacterium Anabaena ◽  
Flow Through

Acetaldehyde was shown to be an irreversible inhibitor of nitrogenase, hydrogenase, CO2 fixation and growth in the cyanobacterium Anabaena cylindrica, but had no effect on photosynthetic electron flow as measured by Methyl Viologen-dependent O2 uptake. The concentration-dependence of the inhibition of nitrogenase and hydrogenase activities was determined, and it was shown that acetaldehyde inhibition poses problems for anaerobic experiments in which the activities of these enzymes are measured in the presence of the frequently used glucose/glucose oxidase/catalase/ethanol O2 trap. It is suggested that acetaldehyde may find use as an inhibitor in experiments designed to separate electron flow through the photosystems from consequent fixation of CO2 and N2.

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