Publications

• The preparation of isocitric dehydrogenase from mammalian heart.

  SIEBERT G., DUBUC J., WARNER R.C., PLAUT G.W.

  J Biol Chem 226:965-975(1957) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Partial purification and characterization of the isocitric dehydrogenase from Trypanosoma cruzi.

  AGOSIN M., WEINBACH E.C.

  Biochim Biophys Acta 21:117-126(1956) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Biochemical and phylogenetic characterization of isocitrate dehydrogenase from a hyperthermophilic archaeon, Archaeoglobus fulgidus.

  Steen I.H., Lien T., Birkeland N.-K.

  A thermostable homodimeric isocitrate dehydrogenase from the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus was purified and characterized. The mol. mass of the isocitrate dehydrogenase subunit was 42 kDa as determined by SDS-PAGE. Following separation by SDS-PAGE, A. fulgidus ... >> More

  A thermostable homodimeric isocitrate dehydrogenase from the hyperthermophilic sulfate-reducing archaeon Archaeoglobus fulgidus was purified and characterized. The mol. mass of the isocitrate dehydrogenase subunit was 42 kDa as determined by SDS-PAGE. Following separation by SDS-PAGE, A. fulgidus isocitrate dehydrogenase could be renatured and detected in situ by activity staining. The enzyme showed dual coenzyme specificity with a high preference for NADP+. Optimal temperature for activity was 90 degrees C or above, and a half-life of 22 min was found for the enzyme when incubated at 90 degrees C in a 50 mM Tricine-KOH buffer (pH 8.0). Based on the N-terminal amino acid sequence, the gene encoding the isocitrate dehydrogenase was cloned. DNA sequencing identified the icd gene as an open reading frame encoding a protein of 412 amino acids with a molecular mass corresponding to that determined for the purified enzyme. The deduced amino acid sequence closely resembled that of the isocitrate dehydrogenase from the archaeon Caldococcus noboribetus (59% identity) and bacterial isocitrate dehydrogenases, with 57% identity with isocitrate dehydrogenase from Escherichia coli. All the amino acid residues directly contacting substrate and coenzyme (except Ile-320) in E. coli isocitrate dehydrogenase are conserved in the enzyme from A. fulgidus. The primary structure of A. fulgidus isocitrate dehydrogenase confirmes the presence of Bacteria-type isocitrate dehydrogenases among Archaea. Multiple alignment of all the available amino acid sequences of di- and multimeric isocitrate dehydrogenases from the three domains of life shows that they can be divided into three distinct phylogenetic groups. << Less

  Arch. Microbiol. 168:412-420(1997) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Purification of the isocitric enzyme (triphosphopyridine nucleotide-linked isocitric dehydrogenase-oxalosuccinic carboxylase).

  DIXON M., MOYLE J.

  Biochem J 63:548-552(1956) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Crystal structure of porcine mitochondrial NADP+-dependent isocitrate dehydrogenase complexed with Mn2+ and isocitrate. Insights into the enzyme mechanism.

  Ceccarelli C., Grodsky N.B., Ariyaratne N., Colman R.F., Bahnson B.J.

  The crystal structure of porcine heart mitochondrial NADP+-dependent isocitrate dehydrogenase (IDH) complexed with Mn2+ and isocitrate was solved to a resolution of 1.85 A. The enzyme was expressed in Escherichia coli, purified as a fusion protein with maltose binding protein, and cleaved with thr ... >> More

  The crystal structure of porcine heart mitochondrial NADP+-dependent isocitrate dehydrogenase (IDH) complexed with Mn2+ and isocitrate was solved to a resolution of 1.85 A. The enzyme was expressed in Escherichia coli, purified as a fusion protein with maltose binding protein, and cleaved with thrombin to yield homogeneous enzyme. The structure was determined by multiwavelength anomalous diffraction phasing using selenium substitution in the form of selenomethionine as the anomalous scatterer. The porcine NADP+-IDH enzyme is structurally compared with the previously solved structures of IDH from E. coli and Bacillus subtilis that share 16 and 17% identity, respectively, with the mammalian enzyme. The porcine enzyme has a protein fold similar to the bacterial IDH structures with each monomer folding into two domains. However, considerable differences exist between the bacterial and mammalian forms of IDH in regions connecting core secondary structure. Based on the alignment of sequence and structure among the porcine, E. coli, and B. subtilis IDH, a putative phosphorylation site has been identified for the mammalian enzyme. The active site, including the bound Mn2+-isocitrate complex, is highly ordered and, therefore, mechanistically informative. The consensus IDH mechanism predicts that the Mn2+-bound hydroxyl of isocitrate is deprotonated prior to its NADP+-dependent oxidation. The present crystal structure has an active site water that is well positioned to accept the proton and ultimately transfer the proton to solvent through an additional bound water. << Less

  J. Biol. Chem. 277:43454-43462(2002) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• A suggested new nomenclature for the isomers of isocitric acid.

  VICKERY H.B.

  J Biol Chem 237:1739-1741(1962) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Cytosolic NADP+-dependent isocitrate dehydrogenase plays a key role in lipid metabolism.

  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., Huh T.L.

  NADPH is an essential cofactor for many enzymatic reactions including glutathione metabolism and fat and cholesterol biosynthesis. We have reported recently an important role for mitochondrial NADP(+)-dependent isocitrate dehydrogenase in cellular defense against oxidative damage by providing NADP ... >> More

  NADPH is an essential cofactor for many enzymatic reactions including glutathione metabolism and fat and cholesterol biosynthesis. We have reported recently an important role for mitochondrial NADP(+)-dependent isocitrate dehydrogenase in cellular defense against oxidative damage by providing NADPH needed for the regeneration of reduced glutathione. However, the role of cytosolic NADP(+)-dependent isocitrate dehydrogenase (IDPc) is still unclear. We report here for the first time that IDPc plays a critical role in fat and cholesterol biosynthesis. During differentiation of 3T3-L1 adipocytes, both IDPc enzyme activity and its protein content were increased in parallel in a time-dependent manner. Increased expression of IDPc by stable transfection of IDPc cDNA positively correlated with adipogenesis of 3T3-L1 cells, whereas decreased IDPc expression by an antisense IDPc vector retarded adipogenesis. Furthermore, transgenic mice with overexpressed IDPc exhibited fatty liver, hyperlipidemia, and obesity. In the epididymal fat pads of the transgenic mice, the expressions of adipocyte-specific genes including peroxisome proliferator-activated receptor gamma were markedly elevated. The hepatic and epididymal fat pad contents of acetyl-CoA and malonyl-CoA in the transgenic mice were significantly lower, whereas the total triglyceride and cholesterol contents were markedly higher in the liver and serum of transgenic mice compared with those measured in wild type mice, suggesting that the consumption rate of those lipogenic precursors needed for fat biosynthesis must be increased by elevated IDPc activity. Taken together, our findings strongly indicate that IDPc would be a major NADPH producer required for fat and cholesterol synthesis. << Less

  J Biol Chem 279:39968-39974(2004) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Crystal Structure of the Isocitrate Dehydrogenase 2 from Acinetobacter baumannii (AbIDH2) Reveals a Novel Dimeric Structure with Two Monomeric-IDH-Like Subunits.

  Wang P., Wu Y., Liu J., Song P., Li S., Zhou X., Zhu G.

  Monomeric isocitrate dehydrogenases (IDHs) have a single polypeptide sizing around 85 kDa. The IDH2 from the opportunistic bacterium <i>Acinetobacter baumannii</i> (AbIDH2) with a mass of 83 kDa was formerly recognized as a typical monomeric IDH. However, both size exclusion chromatography and ana ... >> More

  Monomeric isocitrate dehydrogenases (IDHs) have a single polypeptide sizing around 85 kDa. The IDH2 from the opportunistic bacterium <i>Acinetobacter baumannii</i> (AbIDH2) with a mass of 83 kDa was formerly recognized as a typical monomeric IDH. However, both size exclusion chromatography and analytical ultracentrifugation analysis indicated that AbIDH2 exists as a homodimer in solution. The crystallographic study of the substrate/coenzyme-free AbIDH2 gave a dimeric structure and each subunit contained a domain I and a domain II. The dimeric assembly is mainly stabilized by hydrophobic interactions (16 hydrogen bonds and 11 salt bridges) from the dimer's interface platform, which centered around the three parallel helices (α4, α12, and α17) and one loop from the domain II. Kinetic analysis showed that the dimeric AbIDH2 showed much lower catalytic efficiency (0.39 μM^-1·s^-1) as compared to the typical monomeric IDHs (~15 μM^-1·s^-1). Key residues crucial for dimer formation were simultaneously changed to generate the mutant mAbIDH2. The disruption of the hydrophobic forces disassociated the dimeric AbIDH2, making mAbIDH2 a monomeric enzyme. mAbIDH2 sustained specific activity (21.9 ± 2 U/mg) comparable to AbIDH2 (25.4 ± 0.7 U/mg). However, mAbIDH2 proved to be a thermolabile enzyme, indicating that the thermostable dimeric AbIDH2 may have a physiological significance for the growth and pathogenesis of <i>A</i>. <i>baumannii</i>. Phylogenetic analysis demonstrated the existence of numerous AbIDH2 homologous proteins, thus expanding the monomeric IDH protein family. << Less

  Int J Mol Sci 19:E1131-E1131(2018) [PubMed] [EuropePMC]

• Isocitrate dehydrogenases from Haloferax volcanii and Sulfolobus solfataricus: enzyme purification, characterisation and N-terminal sequence.

  Camacho M.L., Brown R.A., Bonete M.J., Danson M.J., Hough D.W.

  The isocitrate dehydrogenases from the extremely halophilic Archaeon, Haloferax volcanii, and from the hyperthermophilic Archaeon, Sulfolobus solfataricus, have been purified to electrophoretic homogeneity. The purified enzymes have been characterised with respect to their cofactor specificities, ... >> More

  The isocitrate dehydrogenases from the extremely halophilic Archaeon, Haloferax volcanii, and from the hyperthermophilic Archaeon, Sulfolobus solfataricus, have been purified to electrophoretic homogeneity. The purified enzymes have been characterised with respect to their cofactor specificities, subunit compositions and their salt and thermal stabilities. N-terminal amino acid sequences have been determined for both enzymes, and multiple alignments with sequences of bacterial and eukaryotic isocitrate dehydrogenases show that the archaeal enzymes most closely resemble the NADP-linked dimeric isocitrate dehydrogenases from the Bacteria. << Less

  FEMS Microbiol. Lett. 134:85-90(1995) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.