scholarly journals Investigation of the electron-transfer properties of cytochrome c oxidase covalently cross-linked to Fe- or Zn-containing cytochrome c

1992 ◽  
Vol 287 (3) ◽  
pp. 951-956 ◽  
Author(s):  
T A Alleyne ◽  
M T Wilson ◽  
G Antonini ◽  
F Malatesta ◽  
B Vallone ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Redox Properties ◽  
Cross Linking ◽  
Stopped Flow ◽  
Steady State Levels ◽  
Electron Transfer Properties ◽  
Transfer Properties ◽  
Flow Experiments ◽  
Covalent Complex

Complexes of cytochrome c oxidase and cytochrome c (Fe- or Zn-containing) have been prepared by 1-ethyl-3-[3-(dimethylamino)propyl]carbodi-imide (EDC) cross-linking. The site to which the cytochrome c covalently binds has been identified as being the same, or close to, the site occupied by cytochrome c in the electrostatic complex which may be formed between the proteins. Stopped-flow experiments, monitored either at a single wavelength or through a rapid wavelength-scan facility, showed that covalently bound Fe-containing cytochrome c cannot donate electrons to cytochrome a. Free Fe-containing cytochrome c was, however, able to transfer electrons to cytochrome a in covalent complexes containing either Fe- or Zn-containing cytochrome c. Turnover experiments showed that the complexed enzyme remains catalytically competent but with decreased (40-80%) activity. The steady-state levels of reduction of both free cytochrome c and cytochrome a in the covalent complex were higher than found in the control (uncomplexed) enzyme. These results are discussed with reference to the structure of the covalent complex and lead us to conclude that cytochrome a may accept electrons directly from free cytochrome c and that cross-linking impairs the redox properties of the CuA site.

Semisynthesis of bipyridyl-alanine cytochrome c mutants: novel proteins with enhanced electron-transfer properties

1993 ◽  
Vol 115 (18) ◽  
pp. 8455-8456 ◽  
Author(s):  
Deborah S. Wuttke ◽  
Harry B. Gray ◽  
Stewart L. Fisher ◽  
Barbara Imperiali
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Novel Proteins ◽  
Electron Transfer Properties ◽  
Transfer Properties

Electrolyte-gated transistors based on phenyl-C61-butyric acid methyl ester (PCBM) films: bridging redox properties, charge carrier transport and device performance

2018 ◽  
Vol 54 (43) ◽  
pp. 5490-5493 ◽  
Author(s):  
Tian Lan ◽  
Francesca Soavi ◽  
Massimo Marcaccio ◽  
Pierre-Louis Brunner ◽  
Jonathan Sayago ◽  
...  
Keyword(s):  
Electronic Transport ◽  
Carrier Transport ◽  
Acid Methyl Ester ◽  
Redox Properties ◽  
Device Performance ◽  
Acid Methyl ◽  
Butyric Acid Methyl Ester ◽  
Electron Transfer Properties ◽  
Transfer Properties ◽  
Shed Light

We shed light on the correlation between electron transfer properties, ionic and electronic transport as well as device performance in ionic liquid (IL)-gated PCBM transistors.

A study of the electron transfer properties of the heme undecapeptide from cytochrome c by 1H nmr spectroscopy

1981 ◽  
Vol 15 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Keisaku Kimura ◽  
Jim Peterson ◽  
Michael Wilson ◽  
David J. Cookson ◽  
Robert J.P. Williams
Keyword(s):  
Electron Transfer ◽  
Nmr Spectroscopy ◽  
Cytochrome C ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Electron Transfer Properties ◽  
Transfer Properties

scholarly journals Kinetic studies on the reaction between cytochrome c oxidase and ferrocytochrome c

1975 ◽  
Vol 147 (1) ◽  
pp. 145-153 ◽  
Author(s):  
M T Wilson ◽  
C Greenwood ◽  
M Brunori ◽  
E Antonini
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Time Course ◽  
Kinetic Studies ◽  
Initial Reaction ◽  
Fast Phase ◽  
Ferrocytochrome C ◽  
Cytochrome C2 ◽  
Kinetics Of ◽  
Flow Experiments

In stopped-flow experiments in which oxidized cytochrome c oxidase was mixed with ferrocytochrome c in the presence of a range of oxygen concentrations and in the absence and presence of cyanide, a fast phase, reflecting a rapid approach to an equilibrium, was observed. Within this phase, one or two molecules of ferrocytochrome were oxidized per haem group of cytochrome a, depending on the concentration of ferrocytochrome c used. The reasons for this are discussed in terms of a mechanism in which all electrons enter through cytochrome a, which, in turn, is in rapid equilibrium with a second site, identified with ‘visible’ copper (830 nm-absorbing) Cud (Beinert et al., 1971). The value of the bimolecular rate constant for the reaction between cytochromes c2+ and a3+ was between 10(6) and 10(7) M(-1)-S(-1); some variability from preparation to preparation was observed. At high ferrocytochrome c concentrations, the initial reaction of cytochrome c2+ with cytochrome a3+ could be isolated from the reaction involving the ‘visible’ copper and the stoicheiometry was found to approach one molecule of cytochrome c2+ oxidized for each molecule of cytochrome a3+ reduced. At low ferrocytochrome c concentrations, however, both sites (i.e. cytochrome a and Cud) were reduced simultaneously and the stoicheiometry of the initial reaction was closer to two molecules of cytochrome c2+ oxidized per molecule of cytochrome a reduced. The bleaching of the 830 nm band lagged behind or was simultaneous with the formation of the 605 nm band and does not depend on the cytochrome c concentration, whereas the extinction at the steady-state does. The time-course of the return of the 830 nm-absorbing species is much faster than the bleaching of the 605 nm-absorbing component, and parallels that of the turnover phase of cytochrome c2+ oxidation. Additions of cyanide to the oxidase preparations had no effect on the observed stoicheiometry or kinetics of the reduction of cytochrome a and ‘visible’ copper, but inhibited electron transfer to the other two sites, cytochrome a3 and the undetectable copper, Cuu.

Topological and Electron-Transfer Properties of Yeast Cytochrome c Adsorbed on Bare Gold Electrodes

ChemPhysChem ◽  
2003 ◽  
Vol 4 (11) ◽  
pp. 1183-1188 ◽  
Author(s):  
Beatrice Bonanni ◽  
Dario Alliata ◽  
Anna Rita Bizzarri ◽  
Salvatore Cannistraro
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Gold Electrodes ◽  
Electron Transfer Properties ◽  
Transfer Properties ◽  
Bare Gold

Isolation of cDNAs encoding subunit VIb of human cytochrome c oxidase and steady-state levels of coxVIb mRNA in different tissues

Gene ◽  
1990 ◽  
Vol 93 (2) ◽  
pp. 285-291 ◽  
Author(s):  
Jan-Willem Taanman ◽  
Cobi Schrage ◽  
Nico J. Ponne ◽  
Atze T. Das ◽  
Piet A. Bolhuis ◽  
...  
Keyword(s):  
Steady State ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Human Cytochrome ◽  
Steady State Levels ◽  
Human Cytochrome C ◽  
Different Tissues
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