Role of arginine-38 in regulation of the cytochrome c oxidation-reduction equilibrium

Biochemistry ◽  
1989 ◽  
Vol 28 (8) ◽  
pp. 3188-3197 ◽  
Author(s):  
Robert L. Cutler ◽  
Anne M. Davies ◽  
Steve Creighton ◽  
Arieh Warshel ◽  
Geoffrey R. Moore ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Oxidation Reduction

scholarly journals The oxidation-state-dependent ATP-binding site of cytochrome c. Implication of an essential arginine residue and the effect of occupancy on the oxidation-reduction potential

1988 ◽  
Vol 252 (2) ◽  
pp. 349-355 ◽  
Author(s):  
B E Corthésy ◽  
C J Wallace
Keyword(s):  
Cytochrome C ◽  
Oxidation State ◽  
Dependent Manner ◽  
Redox Potentials ◽  
Redox Systems ◽  
Atp Binding Site ◽  
Oxidation Reduction ◽  
State Dependent ◽  
Oxidation Reduction Potential

Arg-91 is not part of the active site of cytochrome c that mediates binding and electron transfer, yet it is absolutely conserved in eukaryotic cytochromes c, indicating a special function. The physicochemical properties of analogues are unaffected by the modification of this residue, so they can be used with confidence to study the role of Arg-91. We have established limiting conditions under which this residue alone is specifically modified by cyclohexane-1,2-dione, and have subsequently shown that ATP, and to a lesser extent ADP or Pi, protects it from the action of the reagent in an oxidation-state-dependent manner. These observations strongly support the idea that this site exerts a controlling influence on cytochrome c activity in the electron transport or other cellular redox systems, and we have commenced a study of how that influence might operate. We find that the redox potentials of both cytochrome c and analogue are little affected by changing ATP or Pi concentrations.

Activation of cytochrome c to a peroxidase compound I-type intermediate by H2O2: relevance to redox signalling in apoptosis

2004 ◽  
Vol 71 ◽  
pp. 97-106 ◽  
Author(s):  
Mark Burkitt ◽  
Clare Jones ◽  
Andrew Lawrence ◽  
Peter Wardman
Keyword(s):  
Cytochrome C ◽  
Hydroxyl Radical ◽  
Redox Regulation ◽  
Chemotherapeutic Agents ◽  
Tyrosyl Radical ◽  
Compound I ◽  
Definitive Evidence ◽  
Enhanced Production ◽  
Physico Chemical

The release of cytochrome c from mitochondria during apoptosis results in the enhanced production of superoxide radicals, which are converted to H2O2 by Mn-superoxide dismutase. We have been concerned with the role of cytochrome c/H2O2 in the induction of oxidative stress during apoptosis. Our initial studies showed that cytochrome c is a potent catalyst of 2′,7′-dichlorofluorescin oxidation, thereby explaining the increased rate of production of the fluorophore 2′,7′-dichlorofluorescein in apoptotic cells. Although it has been speculated that the oxidizing species may be a ferryl-haem intermediate, no definitive evidence for the formation of such a species has been reported. Alternatively, it is possible that the hydroxyl radical may be generated, as seen in the reaction of certain iron chelates with H2O2. By examining the effects of radical scavengers on 2′,7′-dichlorofluorescin oxidation by cytochrome c/H2O2, together with complementary EPR studies, we have demonstrated that the hydroxyl radical is not generated. Our findings point, instead, to the formation of a peroxidase compound I species, with one oxidizing equivalent present as an oxo-ferryl haem intermediate and the other as the tyrosyl radical identified by Barr and colleagues [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503]. Studies with spin traps indicated that the oxo-ferryl haem is the active oxidant. These findings provide a physico-chemical basis for the redox changes that occur during apoptosis. Excessive changes (possibly catalysed by cytochrome c) may have implications for the redox regulation of cell death, including the sensitivity of tumour cells to chemotherapeutic agents.

scholarly journals Role of cytochrome c heme lyase in the import of cytochrome c into mitochondria.

1988 ◽  
Vol 263 (35) ◽  
pp. 19034-19042 ◽  
Author(s):  
D W Nicholson ◽  
C Hergersberg ◽  
W Neupert
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Heme Lyase

scholarly journals Possible Role of Peroxynitrite in the Responses Induced by Fusicoccin in Plant Cultured Cells

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 182 ◽  
Author(s):  
Massimo Malerba ◽  
Raffaella Cerana
Keyword(s):  
Cytochrome C ◽  
Dna Fragmentation ◽  
Stress Responses ◽  
Molecular Chaperones ◽  
Caspase 3 ◽  
Cultured Cells ◽  
Acer Pseudoplatanus ◽  
Cytochrome C Release ◽  
Induced Stress

Fusicoccin (FC) is a well-known phytotoxin able to induce in Acer pseudoplatanus L. (sycamore) cultured cells, a set of responses similar to those induced by stress conditions. In this work, the possible involvement of peroxynitrite (ONOO−) in FC-induced stress responses was studied measuring both in the presence and in the absence of 2,6,8-trihydroxypurine (urate), a specific ONOO− scavenger: (1) cell death; (2) specific DNA fragmentation; (3) lipid peroxidation; (4) production of RNS and ROS; (5) activity of caspase-3-like proteases; and (6) release of cytochrome c from mitochondria, variations in the levels of molecular chaperones Hsp90 in the mitochondria and Hsp70 BiP in the endoplasmic reticulum (ER), and of regulatory 14-3-3 proteins in the cytosol. The obtained results indicate a role for ONOO− in the FC-induced responses. In particular, ONOO− seems involved in a PCD form showing apoptotic features such as specific DNA fragmentation, caspase-3-like protease activity, and cytochrome c release from mitochondria.

A role of flavonoids in cytochrome c-cardiolipin interactions

2021 ◽  
Vol 33 ◽  
pp. 116043
Author(s):  
Malaysha Rice ◽  
Bokey Wong ◽  
Mare Oja ◽  
Kelley Samuels ◽  
Alicia K. Williams ◽  
...  
Keyword(s):  
Cytochrome C
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