Proton translocation by the mitochondrial cytochrome b-c1 complex is inhibited by NN'-dicyclohexylcarbodi-imide

Biochem J. 1982 Aug 15;206(2):419-21. doi: 10.1042/bj2060419.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carbodiimides / pharmacology*
  • Cell Membrane Permeability / drug effects
  • Dicyclohexylcarbodiimide / pharmacology*
  • Electron Transport Complex III
  • In Vitro Techniques
  • Mitochondria, Liver / drug effects
  • Mitochondria, Liver / enzymology*
  • Multienzyme Complexes / antagonists & inhibitors*
  • NADH, NADPH Oxidoreductases / antagonists & inhibitors*
  • Protons*
  • Quinone Reductases / antagonists & inhibitors*
  • Rats

Substances

  • Carbodiimides
  • Multienzyme Complexes
  • Protons
  • Dicyclohexylcarbodiimide
  • NADH, NADPH Oxidoreductases
  • Quinone Reductases
  • Electron Transport Complex III