Thermodynamic and steady-state-kinetic investigation of the effect of NN'-dicyclohexylcarbodi-imide on H+ translocation by the mitochondrial cytochrome bc1 complex.
Steady-state kinetic measurements showed that NN'-dicyclohexylcarbodi-imide decreased the observed H+/2e ratio of H+ transport by mitochondria respiring on succinate, acting mainly at the cytochrome bc1 complex. Thermodynamic assessment of the H+/2e ratio by measuring the force ratio across the bc1 complex showed that the inhibitor did not affect H+ translocation. Possible explanations of this disagreement between methods are examined; we conclude that the inhibitor does not alter the mechanistic stoichiometry of H+ pumping by the bc1 complex.
Brand
M D
MD
Al-Shawi
M K
MK
Brown
G C
GC
Price
B D
BD
D000818:Animals; D002234:Carbodiimides / Q000494:pharmacology*; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D014450:Electron Transport Complex III; D066298:In Vitro Techniques; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects / Q000201:enzymology*; D009097:Multienzyme Complexes / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism*; D011522:Protons; D011808:Quinone Reductases / Q000378:metabolism*; D051381:Rats; D013816:Thermodynamics
D002234:Carbodiimides; D009097:Multienzyme Complexes; D011522:Protons; D004024:Dicyclohexylcarbodiimide; D009247:NADH, NADPH Oxidoreductases; D011808:Quinone Reductases; D014450:Electron Transport Complex III