The Journal of Membrane Biology

, Volume 17, Issue 1, pp 155–180

Complexes between uncouplers of oxidative phosphorylation

  • Margaret Foster
  • Stuart McLaughlin

DOI: 10.1007/BF01870177

Cite this article as:
Foster, M. & McLaughlin, S. J. Membrain Biol. (1974) 17: 155. doi:10.1007/BF01870177


We have examined the effects of two weak acid uncouplers of oxidative phosphorylation, 2,4-dinitrophenol and 5,6-dichloro-2-trifluoromethyl-benzimidazole, on the electrical properties of phospholipid bilayer membranes. All the effects they produce are consistent with the charged permeant species being a HA2 complex formed between the neutral acid HA and its anion A and the current in the aqueous phases being carried by buffered hydrogen ions. When both uncouplers are present simultaneously, all the evidence we have obtained is consistent with the charged permeant species being a HAB complex formed between the neutral acid HA of one uncoupler and the anion B of the other. It was necessary, however, to take into account interfacial processes and the unstirred layers adjacent to the membrane, the adsorption of anions to the bilayer and the buffer level in the aqueous phases to explain the results in terms of this model. The degree to which these factors will complicate a comparison of results obtained on artificial systems and mitochondria is also discussed.

Copyright information

© Springer-Verlag New York Inc. 1974

Authors and Affiliations

  • Margaret Foster
    • 1
  • Stuart McLaughlin
    • 1
  1. 1.Department of Physiology and Biophysics, Health Sciences CenterState University of New YorkStony Brook
  2. 2.Department of BiologyUniversity of California at San DiegoLa Jolla