Proton translocation by the mitochondrial cytochrome b-c1 complex is inhibited by NN'-dicyclohexylcarbodi-imide.
NN'-Dicyclohexylcarbodi-imide at low concentrations decreases the H+/2e ratio for rat liver mitochondria over the span succinate to oxygen from 5.9 +/- 0.3 (mean +/- S.E.M.) to 4.0 +/- 0.1 and for the cytochrome b-c1 complex from 3.8 +/- 0.2 to 1.9 +/- 0.1, but has little effect on the H+/2e ratio of cytochrome oxidase. The decrease in stoicheiometry is due, not to uncoupling or inhibition of electron transport, but to inhibition of proton translocation. NN'-Dicyclohexylcarbodi-imide thus 'decouples' proton translocation in the cytochrome b-c1 complex.
D000818:Animals; D002234:Carbodiimides / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology*; D014450:Electron Transport Complex III; D066298:In Vitro Techniques; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors*; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors*; D011522:Protons; D011808:Quinone Reductases / Q000037:antagonists & inhibitors*; D051381:Rats
D002234:Carbodiimides; D009097:Multienzyme Complexes; D011522:Protons; D004024:Dicyclohexylcarbodiimide; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D014450:Electron Transport Complex III