[Protamine as a specific inhibitor of electron transport between cytochromes c and a on the outer surface of the mitochondrial membrane]

Biokhimiia. 1975 Mar-Apr;40(2):401-7.
[Article in Russian]


The basic protein protamine is found to be a potent inhibitor of mitochondrial cytochrome c oxidase, while the oxidase activity of the "inside out" submitochondrial particles is only slightly affected by this polycation. The site of inhibition of mitochondrial respiration by protamine is localized between cytochromes c and a, protamine combining with cytochrome oxidase competitively to cytochrome, c, Ki=2,5 x 10(-6) M. The data obtained suggest that it is the outer side of the mitochondrial membrane where oxidation of cytochrome c by cytochrome a occurs.

Publication types

  • English Abstract

MeSH terms

  • Animals
  • Cattle
  • Cytochrome c Group / metabolism
  • Cytochromes / metabolism*
  • Electron Transport / drug effects
  • Electron Transport Complex IV / antagonists & inhibitors*
  • Membranes / metabolism
  • Mitochondria, Muscle / metabolism*
  • Myocardium / metabolism
  • Oxidation-Reduction
  • Protamines / pharmacology*


  • Cytochrome c Group
  • Cytochromes
  • Protamines
  • Electron Transport Complex IV