Electrochemical studies of heme proteins. Coulometric, polarographic, and combined spectroelectrochemical methods for reduction of the heme prosthetic group in cytochrome c

1972 ◽  
Vol 94 (23) ◽  
pp. 8197-8204 ◽  
Author(s):  
Stephen R. Betso ◽  
Michael H. Klapper ◽  
Larry B. Anderson
Keyword(s):  
Cytochrome C ◽  
Heme Proteins ◽  
Electrochemical Studies ◽  
Prosthetic Group ◽  
Heme Prosthetic Group

scholarly journals Heme-a, the heme prosthetic group of cytochrome c oxidase, is increased in Alzheimer's disease

2009 ◽  
Vol 461 (3) ◽  
pp. 302-305 ◽  
Author(s):  
Barney E. Dwyer ◽  
Meghan L. Stone ◽  
Nadia Gorman ◽  
Peter R. Sinclair ◽  
George Perry ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Prosthetic Group ◽  
Heme Prosthetic Group

Cytochrome c and cytochrome c oxidase interactions: the effects of ionic strength and hydrostatic pressure studied with site-specific modifications of cytochrome c

1992 ◽  
Vol 70 (7) ◽  
pp. 539-547 ◽  
Author(s):  
Jack A. Kornblatt ◽  
Janice Theodorakis ◽  
Gaston Hui Bon Hoa ◽  
Emmanuel Margoliash
Keyword(s):  
Hydrostatic Pressure ◽  
Cytochrome C ◽  
Cytochrome Oxidase ◽  
Cytochrome C Oxidase ◽  
Front Surface ◽  
Prosthetic Group ◽  
Binding Interaction ◽  
Cytochromes C ◽  
Heme Prosthetic Group ◽  
Full Charge

Seven cytochromes c, in which individual lysines have been modified to the propylthiobimane derivatives, have been prepared. These derivatives were also converted to the porphyrin cytochromes c by treatment with HF. The properties of both types of modified proteins were studied in their reactions with cytochrome c oxidase. The results show that lysines 25, 27, 60, 72, and 87 do not contribute a full charge to the binding interaction with the oxidase. These five residues, with the exception of the lysine-60 derivative, are on the front surface of the protein and contain the solvent-accessible edge of the heme prosthetic group. By contrast, lysines 8 and 13 at the top of the front surface do contribute a full charge to the binding interaction with the oxidase. The removal of the positive charge on any one lysine weakens the binding to cytochrome c oxidase by at least 1 kcal (1 cal = 4.1868 J). The presence of bimane at lysines 13 and 87 clearly forces the separation of the cytochrome c and oxidase, but this does not occur with the other complexes. The bimane-modified lysine-13 protein, and to a lesser extent that modified at lysine 8, show the interesting effect of enhanced complex formation with cytochrome c oxidase when subjected to pressure, possibly because of entrapment of water at the newly created interface of the complex. Our observations indicate that the two proteins of the cytochrome c – cytochrome oxidase complex have preferred, but not obligatory, spatial orientations and that interaction occurs without either protein losing significant portions of its hydration shell.Key words: cytochrome oxidase, cytochrome c, binding, hydrostatic pressure.

Biocatalytic oxidation of polycyclic aromatic hydrocarbons in media containing organic solvents

1997 ◽  
Vol 36 (10) ◽  
pp. 37-44 ◽  
Author(s):  
Eduardo Torres ◽  
Raunel Tinoco ◽  
Rafael Vazquez-Duhalt
Keyword(s):  
Cytochrome C ◽  
Organic Solvents ◽  
Oxidation Mechanism ◽  
Site Directed Mutagenesis ◽  
Solvent Mixtures ◽  
Reaction Products ◽  
Prosthetic Group ◽  
Mass Transfer Limitation ◽  
Polycyclic Aromatic ◽  
Protein Environment

Lignin peroxidase, cytochrome c and haemoglobin were tested for oxidation of polycyclic aromatic hydrocarbon (PAH) in the presence of hydrogen peroxide. The reaction mixture Contained water-miscible organic solvents in order to reduce the mass transfer limitation of hydrophobic substrates. The reaction products from all three haemoproteins were mainly quinones, suggesting the same oxidation mechanism for the three biocatalysts. The haeme prosthetic group must have located in a protein environment for it to catalyze these reactions, and only certain types of protein environment are able to induce this type of haemebased catalytic activity. The solvent hydrophobicity is a factor affecting the biocatalysis in organic media. Substrate partitioning between the active site (haeme) and the bulk solvent is the main factor of the biocatalytic behaviour in organic solvent mixtures. Site-directed mutagenesis of yeast cytochrome c significantly altered the kinetic behaviour of the protein. The Gly82;Thr 102 variant was 10 times more active and showed a catalytic efficiency 10-fold greater than the wild-type iso-1-cytochrome c. These results suggest that it is possible to design a new biocatalyst for environmental purposes.

Integrating cell-free biosyntheses of heme prosthetic group and apoenzyme for the synthesis of functional P450 monooxygenase

2012 ◽  
Vol 110 (4) ◽  
pp. 1193-1200 ◽  
Author(s):  
Yong-Chan Kwon ◽  
In-Seok Oh ◽  
Nahum Lee ◽  
Kyung-Ho Lee ◽  
Yeo Joon Yoon ◽  
...  
Keyword(s):  
Prosthetic Group ◽  
P450 Monooxygenase ◽  
Heme Prosthetic Group

The heme iron coordination of unfolded ferric and ferrous cytochrome c in neutral and acidic urea solutions. Spectroscopic and electrochemical studies

2004 ◽  
Vol 1703 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Milan Fedurco ◽  
Jan Augustynski ◽  
Chiara Indiani ◽  
Giulietta Smulevich ◽  
Marián Antalík ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Heme Iron ◽  
Electrochemical Studies ◽  
Iron Coordination
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