ExplorEnz: EC 1.1.1.42

Your query returned 1 entry. Printable version

1.1.1.42

Accepted name:

isocitrate dehydrogenase (NADP⁺)

Reaction:

isocitrate + NADP⁺ = 2-oxoglutarate + CO₂ + NADPH + H⁺ (overall reaction)
(1a) isocitrate + NADP⁺ = oxalosuccinate + NADPH + H⁺
(1b) oxalosuccinate = 2-oxoglutarate + CO₂

For diagram of the citric-acid cycle, click here

Glossary:

isocitrate = (1R,2S)-1-hydroxypropane-1,2,3-tricarboxylate (previously known as threo-D_s-isocitrate)
oxalosuccinate = 1-oxopropane-1,2,3-tricarboxylate

Other name(s):

oxalosuccinate decarboxylase; oxalsuccinic decarboxylase; isocitrate (NADP) dehydrogenase; isocitrate (nicotinamide adenine dinucleotide phosphate) dehydrogenase; NADP-specific isocitrate dehydrogenase; NADP-linked isocitrate dehydrogenase; NADP-dependent isocitrate dehydrogenase; NADP isocitric dehydrogenase; isocitrate dehydrogenase (NADP-dependent); NADP-dependent isocitric dehydrogenase; triphosphopyridine nucleotide-linked isocitrate dehydrogenase-oxalosuccinate carboxylase; NADP⁺-linked isocitrate dehydrogenase; IDH (ambiguous); dual-cofactor-specific isocitrate dehydrogenase; NADP⁺-ICDH; NADP⁺-IDH; IDP; IDP1; IDP2; IDP3

Systematic name:

isocitrate:NADP⁺ oxidoreductase (decarboxylating)

Comments:

Requires Mn²⁺ or Mg²⁺ for activity. Unlike EC 1.1.1.41, isocitrate dehydrogenase (NAD⁺), oxalosuccinate can 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 [6]. The enzyme from some species can also use NAD⁺ but much more slowly [6,7].

Links to other databases:

BRENDA, EXPASY, GTD, KEGG, MetaCyc, PDB, CAS registry number: 9028-48-2

References:

1.	Agosin, M.U. and Weinbach, E.C. Partial purification and characterization of the isocitric dehydrogenase from Trypanosoma cruzi. Biochim. Biophys. Acta 21 (1956) 117–126. [DOI] [PMID: 13363868]
2.	Moyle, J. and Dixon, M. Purification of the isocitrate enzyme (triphosphopyridine nucleotide-linked isocitrate dehydrogenase-oxalosuccinate carboxylase). Biochem. J. 63 (1956) 548–552. [PMID: 13355848]
3.	Plaut, G.W.E. Isocitrate dehydrogenases. In: Boyer, P.D., Lardy, H. and Myrbäck, K. (Ed.), The Enzymes, 2nd edn, vol. 7, Academic Press, New York, 1963, pp. 105–126.
4.	Siebert, G., Dubuc, J., Warner, R.C. and Plaut, G.W.E. The preparation of isocitrate dehydrogenase from mammalian heart. J. Biol. Chem. 226 (1957) 965–975. [PMID: 13438885]
5.	Vickery, H.B. A suggested new nomenclature for the isomers of isocitric acid. J. Biol. Chem. 237 (1962) 1739–1741. [PMID: 13925783]
6.	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. [DOI] [PMID: 8593959]
7.	Steen, I.H., Lien, T. and Birkeland, N.-K. Biochemical and phylogenetic characterization of isocitrate dehydrogenase from a hyperthermophilic archaeon, Archaeoglobus fulgidus. Arch. Microbiol. 168 (1997) 412–420. [PMID: 9325430]
8.	Koh, H.J., Lee, S.M., Son, B.G., Lee, S.H., Ryoo, Z.Y., Chang, K.T., Park, J.W., Park, D.C., Song, B.J., Veech, R.L., Song, H. and Huh, T.L. Cytosolic NADP⁺-dependent isocitrate dehydrogenase plays a key role in lipid metabolism. J. Biol. Chem. 279 (2004) 39968–39974. [DOI] [PMID: 15254034]
9.	Ceccarelli, C., Grodsky, N.B., Ariyaratne, N., Colman, R.F. and Bahnson, B.J. Crystal structure of porcine mitochondrial NADP⁺-dependent isocitrate dehydrogenase complexed with Mn²⁺ and isocitrate. Insights into the enzyme mechanism. J. Biol. Chem. 277 (2002) 43454–43462. [DOI] [PMID: 12207025]

[EC 1.1.1.42 created 1961, modified 2005]