The effect of nucleotides and mitochondrial chaperonin 10 on the structure and chaperone activity of mitochondrial chaperonin 60

Eur J Biochem. 2001 Jun;268(12):3465-72. doi: 10.1046/j.1432-1327.2001.02243.x.

Abstract

Mitochondrial chaperonins are necessary for the folding of newly imported and stress-denatured mitochondrial proteins. The goal of this study was to investigate the structure and function of the mammalian mitochondrial chaperonin system. We present evidence that the 60 kDa chaperonin (mt-cpn60) exists in solution in dynamic equilibrium between monomers, heptameric single rings and double-ringed tetradecamers. In the presence of ATP and the 10 kDa cochaperonin (mt-cpn10), the formation of a double ring is favored. ADP at very high concentrations does not inhibit malate dehydrogenase refolding or ATP hydrolysis by mt-cpn60 in the presence of mt-cpn10. We propose that the cis (mt-cpn60)14.nucleotide.(mt-cpn10)7 complex is not a stable species and does not bind ADP effectively at its trans binding site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / pharmacology*
  • Adenosine Triphosphatases / metabolism
  • Adenosine Triphosphate / pharmacology*
  • Animals
  • Chaperonin 10 / pharmacology*
  • Chaperonin 60 / chemistry*
  • Chaperonin 60 / metabolism*
  • Malate Dehydrogenase / chemistry
  • Malate Dehydrogenase / metabolism
  • Microscopy, Electron
  • Mitochondria, Heart / metabolism*
  • Protein Denaturation
  • Structure-Activity Relationship
  • Swine
  • Urea / chemistry

Substances

  • Chaperonin 10
  • Chaperonin 60
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • Urea
  • Malate Dehydrogenase
  • Adenosine Triphosphatases