IUBMB Enzyme Nomenclature


Accepted name: isocitrate dehydrogenase (NAD+)

Reaction: isocitrate + NAD+ = 2-oxoglutarate + CO2 + NADH

For diagram click here.

Glossary: isocitrate = (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate (previously known as threo-DS-isocitrate)

Other name(s): isocitric dehydrogenase; β-ketoglutaric-isocitric carboxylase; isocitric acid dehydrogenase; NAD dependent isocitrate dehydrogenase; NAD isocitrate dehydrogenase; NAD-linked isocitrate dehydrogenase; NAD-specific isocitrate dehydrogenase; NAD isocitric dehydrogenase; isocitrate dehydrogenase (NAD); IDH (ambiguous); nicotinamide adenine dinucleotide isocitrate dehydrogenase

Systematic name: isocitrate:NAD+ oxidoreductase (decarboxylating)

Comments: Requires Mn2+ or Mg2+ for activity. Unlike EC, isocitrate dehydrogenase (NADP+), oxalosuccinate cannot be used as a substrate. In eukaryotes, isocitrate dehydrogenase exists in two forms: an NAD+-linked enzyme found only in mitochondria and displaying allosteric properties, and a non-allosteric, NADP+-linked enzyme that is found in both mitochondria and cytoplasm [7]. The enzyme from some species can also use NADP+ but much more slowly [9].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9001-58-5


1. Hathaway, J.A. and Atkinson, D.E. The effect of adenylic acid on yeast nicotinamide adenine dinucleotide isocitrate dehydrogenase, a possible metabolic control mechanism. J. Biol. Chem. 238 (1963) 2875-2881. [PMID: 14063317]

2. Kornberg, A. and Pricer, W.E. Di- and triphosphopyridine nucleotide isocitric dehydrogenase in yeast. J. Biol. Chem. 189 (1951) 123-136. [PMID: 14832224]

3. Plaut, G.W.E. Isocitrate dehydrogenases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Eds.), The Enzymes, 2nd ed., vol. 7, Academic Press, New York, 1963, pp. 105-126.

4. Plaut, G.W.E. and Sung, S.-C. Diphosphopyridine nucleotide isocitric dehydrogenase from animal tissues. J. Biol. Chem. 207 (1954) 305-314. [PMID: 13152105]

5. Ramakrishnan, C.V. and Martin, S.M. Isocitric dehydrogenase in Aspergillus niger. Arch. Biochem. Biophys. 55 (1955) 403-407.

6. Vickery, H.B. A suggested new nomenclature for the isomers of isocitric acid. J. Biol. Chem. 237 (1962) 1739-1741. [PMID: 13925783]

7. Camacho, M.L., Brown, R.A., Bonete, M.J., Danson, M.J. and Hough, D.W. Isocitrate dehydrogenases from Haloferax volcanii and Sulfolobus solfataricus: enzyme purification, characterisation and N-terminal sequence. FEMS Microbiol. Lett. 134 (1995) 85-90. [PMID: 8593959]

8. Kim, Y.O., Koh, H.J., Kim, S.H., Jo, S.H., Huh, J.W., Jeong, K.S., Lee, I.J., Song, B.J. and Huh, T.L. Identification and functional characterization of a novel, tissue-specific NAD+-dependent isocitrate dehydrogenase β subunit isoform. J. Biol. Chem. 274 (1999) 36866-36875. [PMID: 10601238]

9. Inoue, H., Tamura, T., Ehara, N., Nishito, A., Nakayama, Y., Maekawa, M., Imada, K., Tanaka, H. and Inagaki, K. Biochemical and molecular characterization of the NAD+-dependent isocitrate dehydrogenase from the chemolithotroph Acidithiobacillus thiooxidans. FEMS Microbiol. Lett. 214 (2002) 127-132. [PMID: 12204383]

[EC created 1961, modified 2005]

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