Kinetics of cytochrome b oxidation in antimycin-treated submitochondrial particles

Biochemistry ◽  
1982 ◽  
Vol 21 (25) ◽  
pp. 6614-6618 ◽  
Author(s):  
Youssef Hatefi ◽  
Takao Yagi
Keyword(s):  
Cytochrome B ◽  
Submitochondrial Particles ◽  
Kinetics Of

Kinetics of cytochrome b reduction in submitochondrial particles

1981 ◽  
Vol 637 (1) ◽  
pp. 34-42 ◽  
Author(s):  
G. van Ark ◽  
A.K. Raap ◽  
J.A. Berden ◽  
E.C. Slater
Keyword(s):  
Cytochrome B ◽  
Submitochondrial Particles ◽  
Kinetics Of

scholarly journals Generation of superoxide anion by the NADH dehydrogenase of bovine heart mitochondria

1980 ◽  
Vol 191 (2) ◽  
pp. 421-427 ◽  
Author(s):  
J F Turrens ◽  
A Boveris
Keyword(s):  
Cytochrome B ◽  
Nadh Dehydrogenase ◽  
Submitochondrial Particles ◽  
Bovine Heart ◽  
Biphasic Effect ◽  
Carbonyl Cyanide ◽  
Autocatalytic Process ◽  
Ph Range ◽  
Energy Dependent ◽  
O2 Production

Submitochondrial particles from bovine heart in which NADH dehydrogenase is reduced by either addition of NADH and rotenone or by reversed electron transfer generate 0.9 +/- 0.1 nmol of O2-/min per mg of protein at pH 7.4 and at 30 degrees C. When NADH is used as substrate, rotenone, antimycin and cyanide increase O2- production. In NADH- and antimycin-supplemented submitochondrial particles, rotenone has a biphasic effect: it increases O2- production at the NADH dehydrogenase and it inhibits O2- production at the ubiquinone-cytochrome b site. The generation of O2- by the rotenone, the uncoupler carbonyl cyanide rho-trifluoromethoxyphenylhydrazone and oligomycin at concentrations similar to those required to inhibit energy-dependent succinate-NAD reductase. Cyanide did not affect O2- generation at the NADH dehydrogenase, but inhibited O2- production at the ubiquinone-cytochrome b site. Production of O2- at the NADH dehydrogenase is about 50% of the O2- generation but the ubiquinone-cytochrome b area at pH 7.4. Additivity of the two mitochondrial sites of O2- generation was observed over the pH range from 7.0 to 8.8. AN O2–dependent autocatalytic process that requires NADH, submitochondrial particles and adrenaline is described.

scholarly journals Effect of sulphate-limited growth on mitochondrial electron transfer and energy conservation between reduced nicotinamide–adenine dinucleotide and the cytochromes in Torulopsis utilis

1971 ◽  
Vol 124 (1) ◽  
pp. 155-170 ◽  
Author(s):  
B. A. Haddock ◽  
P. B. Garland
Keyword(s):  
Energy Conservation ◽  
Cytochrome B ◽  
Antimycin A ◽  
Alternative Route ◽  
Aerobic Incubation ◽  
Submitochondrial Particles ◽  
Limited Growth ◽  
Sulphide Concentration ◽  
Haem Iron ◽  
Acid Labile

1. Conditions have been established for the sulphate-limited growth of Torulopsis utilis in continuous culture. 2. Mitochondria prepared from sulphate-limited cells lack both piericidin A sensitivity and the first energy-conservation site (site 1). Sensitivity to antimycin A or cyanide and the second and third energy-conservation sites were apparently unaffected by sulphate-limited growth. 3. Aerobic incubation for 8h of sulphate-limited cells with a low concentration of sulphate (50μm or less) resulted in the recovery of mitochondrial piericidin A sensitivity and site 1. The use of higher concentrations of sulphate (250μm or more) still resulted in the recovery of mitochondrial piericidin A sensitivity and site 1, but also resulted in the appearance of a non-phosphorylating oxidase, which mediated oxidation of the respiratory chain at about the level of cytochrome b in an antimycin A- and cyanide-insensitive manner. Both this alternative route and the conventional normal route of respiration were shown to coexist and to intercommunicate at the level of cytochrome b. 4. Low-temperature spectroscopy failed to identify any new respiratory component to explain the alternative route. 5. The apparent affinity of the alternative route for oxygen was similar to that for the conventional route through cytochrome oxidase, namely half-maximal activity at 0.1μm-oxygen or less. 6. The non-haem iron concentration of submitochondrial particles was unaffected by sulphate limitation, whereas the acid-labile sulphide concentration was lowered tenfold. Marked increases (between four- and 30-fold) in the acid-labile sulphide concentration of submitochondrial particles were observed in sulphate-limited cells after aerobic incubation with various concentrations of sulphate. The lowest increase (fourfold) was observed without added sulphate, the highest (30-fold) with 1.0mm added sulphate. 7. The ratio of non-haem iron to acid-labile sulphide in submitochondrial particles varied with different growth conditions from a maximum of 15.0 to a minimum of 0.72. It is suggested that analytical measurements of non-haem iron are an inadequate guide to the concentration of iron–sulphur protein in complex systems. 8. The effects of sulphate-limited growth on site 1 and piericidin sensitivity are interpreted to indicate a role for iron–sulphur protein in these properties. 9. The aerobic incubation of sulphate-limited cells with cycloheximide resulted in the recovery by mitochondria of site 1 but not of piericidin sensitivity. 10. The appearance of the alternative route for cyanide- and antimycin-A (but not piericidin A-) insensitive respiration on incubating sulphate-limited cells with sulphate concentrations higher than 250μm indicates that the alternative route involves an iron–sulphur protein.

scholarly journals Kinetics of the incorporation of cytochrome b 5 , an integral membrane protein, into unilamellar dimyristoyllecithin liposomes

FEBS Letters ◽  
1978 ◽  
Vol 87 (2) ◽  
pp. 269-272 ◽  
Author(s):  
Winchil L.C. Vaz ◽  
Horst Vogel ◽  
Fritz Jähnig ◽  
Robert H. Austin
Keyword(s):  
Membrane Protein ◽  
Cytochrome B ◽  
Integral Membrane Protein ◽  
Kinetics Of
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