Pressure Tuning Voltammetry. Reaction Volumes for Electron Transfer in Cytochrome c and Ruthenium-Modified Cytochromes c

1995 ◽  
Vol 117 (9) ◽  
pp. 2600-2605 ◽  
Author(s):  
J. Sun ◽  
J. F. Wishart ◽  
R. van Eldik ◽  
R. D. Shalders ◽  
T. W. Swaddle
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Pressure Tuning ◽  
Cytochromes C ◽  
Reaction Volumes

scholarly journals Amino Acid Substitutions in the Non-Ordered Ω-Loop 70–85 Affect Electron Transfer Function and Secondary Structure of Mitochondrial Cytochrome c

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 973
Author(s):  
Rita V. Chertkova ◽  
Tatyana V. Bryantseva ◽  
Nadezhda A. Brazhe ◽  
Kseniya S. Kudryashova ◽  
Victor V. Revin ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Secondary Structure ◽  
Cytochrome C ◽  
Cd Spectroscopy ◽  
Mitochondrial Cytochrome ◽  
Proposed Model ◽  
Donor And Acceptor ◽  
Cytochromes C ◽  
Spectroscopy Studies ◽  
Mitochondrial Cytochrome C

The secondary structure of horse cytochrome c with mutations in the P76GTKMIFA83 site of the Ω-loop, exhibiting reduced efficiency of electron transfer, were studied. CD spectroscopy studies showed that the ordering of mutant structure increases by 3–6% compared to that of the WT molecules due to the higher content of β-structural elements. The IR spectroscopy data are consistent with the CD results and demonstrate that some α-helical elements change into β-structures, and the amount of the non-structured elements is decreased. The analysis of the 1H-NMR spectra demonstrated that cytochrome c mutants have a well-determined secondary structure with some specific features related to changes in the heme microenvironment. The observed changes in the structure of cytochrome c mutants are likely to be responsible for the decrease in the conformational mobility of the P76GTKMIFA83 sequence carrying mutations and for the decline in succinate:cytochrome c-reductase and cytochrome c-oxidase activities in the mitoplast system in the presence of these cytochromes c. We suggest that the decreased efficiency of the electron transfer of the studied cytochromes c may arise due to: (1) the change in the protein conformation in sites responsible for the interaction of cytochrome c with complexes III and IV and (2) the change in the heme conformation that deteriorates its optimal orientation towards donor and acceptor in complexes III and IV therefore slows down electron transfer. The results obtained are consistent with the previously proposed model of mitochondrial cytochrome c functioning associated with the deterministic mobility of protein globule parts.

Low-temperature studies of electron transfer between different cytochromes c and cytochrome c oxidase

Biochemistry ◽  
1978 ◽  
Vol 17 (11) ◽  
pp. 2246-2249 ◽  
Author(s):  
Shelagh Ferguson-Miller ◽  
David L. Brautigan ◽  
Britton Chance ◽  
Alan Waring ◽  
E. Margoliash
Keyword(s):  
Electron Transfer ◽  
Low Temperature ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Cytochromes C

scholarly journals Electron transfer from Phanerochaete chrysosporium cellobiose oxidase to equine cytochrome c and Pseudomonas aeruginosa cytochrome c-551

1994 ◽  
Vol 298 (2) ◽  
pp. 329-334 ◽  
Author(s):  
M S Rogers ◽  
G D Jones ◽  
G Antonini ◽  
M T Wilson ◽  
M Brunori
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Cytochrome B ◽  
Gel Chromatography ◽  
Cytochromes C ◽  
Cellulose Breakdown ◽  
Value Decomposition ◽  
Rate Limit ◽  
Positively Charged

The electron-transfer reactions of cellobiose oxidase (CBO) have been investigated by conventional and by rapid-scan stopped-flow spectroscopy at pH 6.0. Analysis of the absorbance/time/wavelength matrix by Singular Value Decomposition (SVD) confirms earlier studies showing that cellobiose rapidly reduces the flavin group (7.7 s-1; cellobiose, 100 microM) which in turn slowly (0.2 s-1) reduces the cytochrome b moiety. In the presence of CBO, cellobiose reduces cytochromes c in a reaction that does not depend on oxygen or superoxide. The rate limit for this process is independent of the source of the cytochromes c and is identical with the rate of cytochrome b reduction. Rapid-mixing experiments show that cytochrome b may donate electrons very rapidly to either mammalian cytochrome c or bacterial cytochrome c-551. The reactions were second-order (kc = 1.75 x 10(7) M-1 x s-1; kc-551 = 4.3 x 10(6) M-1 x s-1; pH 6.0, 21 degrees C and I0.064) and strongly ionic-strength (I)-dependent: kc decreasing with I and kc-551 increasing with I. These results suggest the electron-transfer site near cytochrome b bears a significant negative charge. Equilibrium gel chromatography confirms that CBO oxidase and positively charged mammalian cytochrome c make stable complexes. These results are discussed in terms of a model suggesting an electron-transfer role for cytochrome b in vivo, possibly connected with radical-mediated cellulose breakdown.

scholarly journals Contributions to Cytochrome c Inner- and Outer-Sphere Reorganization Energy

2021 ◽  
Author(s):  
Samir Chattopadhyay ◽  
Manjistha Mukherjee ◽  
Banu Kandemir ◽  
Sarah Bowman ◽  
Kara L Bren ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Cytochrome C ◽  
Energy Conversion ◽  
Reorganization Energy ◽  
Outer Sphere ◽  
Water Soluble ◽  
Small Water ◽  
Cytochromes C ◽  
Cytochrome C552 ◽  
Hydrogenobacter Thermophilus

Cytochromes c are small water-soluble proteins that catalyze electron transfer in metabolism and energy conversion processes. Hydrogenobacter thermophilus cytochrome c552 presents a curious case in displaying fluxionality of its heme...

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