Proteinaceous complexes from mitochondrial contact sites

Biochemistry (Mosc). 1999 Apr;64(4):390-8.


A Triton X-100 extract from rat brain mitochondria was obtained using low detergent/protein ratio. From this extract a proteinaceous complex was purified; its molecular weight was as high as 880 kD. The complex contained both hexokinase and creatine kinase activity. When incorporated into phospholipid bilayer membranes, the complex formed a channel whose activity was different than the channel activity of purified porin isolated either by adsorption chromatography or by dissociation from protein complexes. A ligand of the mitochondrial benzodiazepine receptor (Ro5-4864) in submicromolar concentrations had an apparent influence on the kinetic behavior of enzymatic coupling of hexokinase and creatine kinase. It is suggested that the 880-kD complex is formed by mitochondrial contact sites. The role of the isolated protein complex in the formation of nonspecific permeability in mitochondria is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzodiazepinones / metabolism
  • Brain / enzymology
  • Brain / metabolism
  • Brain / physiology
  • Creatine Kinase / metabolism
  • Female
  • Hexokinase / metabolism
  • Membrane Potentials
  • Mitochondria / enzymology
  • Mitochondria / metabolism*
  • Mitochondria / physiology
  • Nerve Tissue Proteins / metabolism*
  • Rats
  • Receptors, GABA-A / metabolism


  • Benzodiazepinones
  • Nerve Tissue Proteins
  • Receptors, GABA-A
  • 4'-chlorodiazepam
  • Hexokinase
  • Creatine Kinase