Two phenotypically compensating isocitrate dehydrogenases inRalstonia eutropha

Mitochondrial isocitrate dehydrogenases from yeast.

A polarographic technique suitable for kinetic studies of either isolated or bound pyridine nucleotide-linked dehydrogenases was used to investigate the isocitrate dehydrogenases of yeast mitochondria. Intact mitochondria were found to contain both triphosphopyridine nucleotideand diphosphopyridine nucleotide-linked isocitrate dehydrogenases with properties very similar to those which have been...

Isocitrate Dehydrogenases in Rainbow-trout Liver

1. The kinetics of the thermally induced enzyme variants of the supernatant NADP-isocitrate dehydrogenase from rainbow-trout liver are investigated. 2. Fish acclimatized to 20C (cold-adapted enzyme) and 170C (warm-adapted enzyme) show different relative distributions of the three NADP-isocitrate dehydrogenase isoenzymes; this has been demonstrated with electrophoresis and electrofocusing techni...

Nondecarboxylating and decarboxylating isocitrate dehydrogenases: oxalosuccinate reductase as an ancestral form of isocitrate dehydrogenase.

Isocitrate dehydrogenase (ICDH) from Hydrogenobacter thermophilus catalyzes the reduction of oxalosuccinate, which corresponds to the second step of the reductive carboxylation of 2-oxoglutarate in the reductive tricarboxylic acid cycle. In this study, the oxidation reaction catalyzed by H. thermophilus ICDH was kinetically analyzed. As a result, a rapid equilibrium random-order mechanism was s...

Single Arginine Mutation in Two Yeast Isocitrate Dehydrogenases: Biochemical Characterization and Functional Implication

Isocitrate dehydrogenase (IDH), a housekeeping gene, has drawn the attention of cancer experts. Mutation of the catalytic Arg132 residue of human IDH1 (HcIDH) eliminates the enzyme's wild-type isocitrate oxidation activity, but confer the mutant an ability of reducing α-ketoglutarate (α-KG) to 2-hydroxyglutarate (2-HG). To examine whether an analogous mutation in IDHs of other eukaryotes could ...

Crystallization, Structure and Functional Robustness of Isocitrate Dehydrogenases