Comparison of the effects of Ca2+, adenine nucleotides and pH on the kinetic properties of mitochondrial NAD(+)-isocitrate dehydrogenase and oxoglutarate dehydrogenase from the yeast Saccharomyces cerevisiae and rat heart

Biochem J. 1994 Oct 15;303 ( Pt 2)(Pt 2):461-5. doi: 10.1042/bj3030461.


The regulatory properties of NAD(+)-isocitrate dehydrogenase and oxoglutarate dehydrogenase in extracts of yeast and rat heart mitochondria were studied under identical conditions. Yeast NAD(+)-isocitrate dehydrogenase exhibits a low K0.5 for isocitrate and is activated by AMP and ADP, but is insensitive to ATP and Ca2+. In contrast, the rat heart NAD(+)-isocitrate dehydrogenase was insensitive to AMP, but was activated by ADP and by Ca2+ in the presence of ADP or ATP. Both yeast and rat heart oxoglutarate dehydrogenase were stimulated by ADP, but only the heart enzyme was activated by Ca2+. All the enzymes studied were activated by decreases in pH, but to differing extents. The effects of Ca2+, adenine nucleotides and pH were through K0.5 for isocitrate or 2-oxoglutarate. These observations are discussed with reference to the deduced amino acid sequences of the constituent subunits of the enzymes, where they are available.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine Nucleotides / pharmacology*
  • Adenosine Diphosphate / pharmacology
  • Adenosine Monophosphate / pharmacology
  • Adenosine Triphosphate / pharmacology
  • Amino Acid Sequence
  • Animals
  • Calcium / pharmacology*
  • Consensus Sequence
  • Hydrogen-Ion Concentration
  • Isocitrate Dehydrogenase / chemistry
  • Isocitrate Dehydrogenase / drug effects*
  • Isocitrate Dehydrogenase / metabolism
  • Ketoglutarate Dehydrogenase Complex / drug effects*
  • Ketoglutarate Dehydrogenase Complex / metabolism
  • Ketoglutaric Acids / pharmacology
  • Kinetics
  • Male
  • Mitochondria, Heart / enzymology*
  • Molecular Sequence Data
  • Rats
  • Saccharomyces cerevisiae / enzymology*


  • Adenine Nucleotides
  • Ketoglutaric Acids
  • Adenosine Monophosphate
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • Isocitrate Dehydrogenase
  • Ketoglutarate Dehydrogenase Complex
  • Calcium