The targets of 2,2',5,5'-tetrachlorobiphenyl in the respiratory chain of rat liver mitochondria revealed by modular kinetic analysis.
The response of the respiratory subsystem of oxidative phosphorylation to the environmental pollutant, 2,2',5,5'-tetrachlorobiphenyl (2,2',5,5'-TCB) was investigated by modular kinetic approach. The effects of 20 microM 2,2',5,5'-TCB on the activity of the respiratory chain modules in rat liver mitochondria oxidizing succinate (+ rotenone) in state 3 were assessed. The toxin inhibited the rate of respiration by 23%. Analysis around cytochrome c revealed that 2,2',5,5'-TCB inhibited both cytochrome c-oxidizing and reducing modules. The toxin inhibited also CoQ-oxidizing module, however it did not affect the kinetics of CoQ-reducing module. Taken together, these data indicated that 2,2',5,5'-TCB inhibited cytochrome bc1 but had no effect on succinate dehydrogenase.
Mildaziene
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Vytautas Magnus University, Kaunas, Lithuania. bioch@kmu.lt
Nauciene
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Z
Krab
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K
D000818:Animals; D001560:Benzidines / Q000494:pharmacology*; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport / Q000187:drug effects*; D004785:Environmental Pollutants / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009097:Multienzyme Complexes; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012402:Rotenone / Q000378:metabolism; D014451:Ubiquinone / Q000378:metabolism
D001560:Benzidines; D003574:Cytochrome c Group; D004785:Environmental Pollutants; D009097:Multienzyme Complexes; D012402:Rotenone; D014451:Ubiquinone; C034088:2,2',5,5'-tetrachlorobenzidine