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Query: EC:1.1.1.41 (
isocitrate dehydrogenase
)
3,101
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The tissue specific patterns and ontogeny of sorbitol dehydrogenase (SDH, EC 1.1.1.14). lactate dehydrogenase (LDH, EC 1.1.1.27) and
isocitrate dehydrogenase
(
IDH
, EC 1.1.1.42) are reported for Barbus tetrazona (tiger barb), B. conchonius (rosy barb), B. nigrofasciatus (black ruby barb), B. titteya (cherry barb), B. sachsi (gold barb), and in interspecific hybrids where B. tetrazona is the maternal parent. The spatial and temporal expression of SDH, LDH and
IDH
isozymes in Barbus is consistent with those reported for other teleosts. As the genetic distance between the parentals used in forming the hybrid increases, allelic expression proceeds from synchronous to asynchronous, with an increasing delay in embryonic gene expression. These observations are consistent with the hypothesis that parental sensor genes differ in their response to maternally controlled regulatory signals; indicative of species specific effector/activator RNA molecule concentrations and sensor/receptor gene induction thresholds.
...
PMID:Ontogenetic patterns of enzyme locus expression in Barbus hybrids (Cypriniformes, Teleostei). 408 6
Mitochondria from cotyledons of Vigna sesquipedalis (L.) Fruwirth (starchy seed) showed no NAD-
isocitric dehydrogenase
(NAD-IDH) activity by the methods which have been known to be useful for the detection of NAD-
IDH
in mitochondria of plants including castor bean and alaska pea. When the Vigna cotyledon mitochondria were treated with glycerol, NAD-
IDH
activity appeared and NADP-
isocitric dehydrogenase
(NADP-IDH) activity was inhibited. The inhibition of mitochondrial NADP-
IDH
by glycerol was overcome by the addition of excess NADP. On the other hand, NADP-
IDH
activity in the soluble fraction of cell components was only slightly inhibited by glycerol and no NAD-
IDH
activity was elicited. It was postulated that NADP-
IDH
in mitochondria is converted to NAD-
IDH
by glycerol and back to NADP-
IDH
with NADP by the alteration in the spatial configuration of the enzyme. However, there could be 2 proteins as the other possibility. The NADP-
IDH
in the soluble fraction which is not subject to such alteration is different from the mitochondrial NADP-
IDH
.
...
PMID:Relative activities of NAD- and NADP- isocritric dehydrogenases in bean mitochondria modified by glycerol or NADP. 438
Electrophoretic variation ascribable to three enzyme loci, coding for a pyruvate kinase (PK1), a glucose phosphate isomerase (GPI1), and an
isocitrate dehydrogenase
(IDH1), was observed in three species of fish of the genus Xiphophorus. Electrophoretic patterns in F1 hybrid heterozygotes confirmed the dimeric structures of GPI and
IDH
, and indicated a multimeric structure for pyruvate kinase. Variant alleles at the three loci exhibited normal Mendelian segregation in backcross hybrids. Linkage analyses indicate a gene order and estimated recombination of PK1--10%--GPI1--41%--IDH1. No significant interference or sex- or population-specific recombination difference was detected. This group (designated linkage group IV) was shown to assort independently from the nine loci comprising linkage groups I, II, and III and from 23 other informative markers, within the limits of the data. No conclusions with respect to homology of linkage relationships could be reached, due to the presence of presumably duplicated loci in these fish coding for isozymes whose homology with enzymes in other vertebrate species is as yet unestablished.
...
PMID:Linkage group IV of fish of the genus Xiphophorus (Poeciliidae): assignment of loci coding for pyruvate kinase-1, glucosephosphate isomerase-1, and isocitrate dehydrogenase-1. 711 84
Cell-free extracts of the obligate methanol-utilizing bacterium Pseudomonas W6 catalyze the oxydation of isocitrate to alpha-ketoglutarate in the presence of NAD+ and NADP+. After electro-focusing of the crude extract of Pseudomonas W6 actually two distinct bands each of NAD+-linked
isocitrate dehydrogenase
(NAD+-
IDH
) and of NADP+-linked isocitrate dehydrogenase (NADP+-IDH) could be observed. The NAD+-
IDH
was completely separated from the NADP+-IDH by employing DEAE ion exchange chromatography and further purified by affinity chromatography using Cibacron blue F 3G-A. The NAD+-
IDH
was inhibited by a high energy charge, whereas the NADP+-IDH was found to be independent of energy charge. Consequently the NAD+-
IDH
showed the control behaviour of an enzyme of an energy-generating sequence which, however, equally fulfils a catabolic and an anabolic function. With respect to the inhibition by reduced pyridine nucleotides and alpha-ketoglutarate differences between NAD+-
IDH
and NADP+-IDH were also found. Only the NADP+-linked enzyme exhibited a feedback inhibition by its reaction products alpha-ketoglutarate and NADPH. This control behaviour gives evidence for the biosynthetic function of the NADP+-IDH. These results confer an amphibolic character to the sequence from citrate to alpha-ketoglutarate in the incomplete citric-acid cycle of Pseudomonas W6.
...
PMID:Regulation of NAD+- and NADP+-linked isocitrate dehydrogenase in the obligate methylotrophic bacterium Pseudomonas W6. 742 52
The expression of two structurally different
isocitrate dehydrogenase
isozymes of Vibrio sp. strain ABE-1 in Escherichia coli was examined. At a low temperature (15 degrees C), a thermolabile and monomeric type isozyme (
IDH
-II), which is quite different in amino acid sequence from the E. coli
isocitrate dehydrogenase
, was expressed and conferred glutamate prototrophic ability on an E. coli mutant defective in
isocitrate dehydrogenase
. The ability of
IDH
-II to confer restoration of the E. coli mutant to glutamate prototrophy was similar to that of
IDH
-I, which is a dimeric enzyme homologous to the E. coli
isocitrate dehydrogenase
. At a high temperature (37 degrees C), no functional
IDH
-II was expressed. Transcription of icdI and icdII genes, which encode
IDH
-I and
IDH
-II, respectively, was regulated differently by different environmental conditions. The level of icdII mRNA was increased by lowering the growth temperature for E. coli transformants, while the level of icdI mRNA was increased when E. coli transformants were cultured in acetate minimal medium. Similar patterns of transcriptional regulation of the two icd gene were observed also in Vibrio sp. strain ABE-1. However, activity of isocitrate dehydrogenase kinase, which can phosphorylate
IDH
-I and consequently inactivate the enzymatic activity, was detected in cell lysates of E. coli but not of Vibrio sp. strain ABE-1.
...
PMID:Differential expression in Escherichia coli of the Vibrio sp. strain ABE-1 icdI and icdII genes encoding structurally different isocitrate dehydrogenase isozymes. 753 33
Peroxisomal NADP-linked isocitrate dehydrogenase (Ps-NADP-IDH) was purified for the first time from Candida tropicalis cells grown on n-alkane as a carbon source, which was effective in proliferation of peroxisomes. The properties of Ps-NADP-
IDH
were compared with those of mitochondrial
NAD-linked isocitrate dehydrogenase
(Mt-NAD-IDH) purified from the cells grown on acetate, in which peroxisomes did not proliferate. Ps-NADP-
IDH
was a homodimer of identical subunits (45 kDa), while Mt-NAD-IDH was suggested to be a heterooctamer composed of two types of subunits with different molecular masses (41 and 38 kDa). Kinetic studies revealed that Ps-NADP-
IDH
gave Michaelis-Menten saturation curves against isocitrate and NADP concentrations, whereas Mt-NAD-IDH was an allosteric enzyme regulated by ATP, AMP, and citrate. Inhibition by 2-oxoglutarate, a precursor of glutamate, was observed only for Ps-NADP-
IDH
. Both enzymes were inhibited by concomitant addition of oxalacetate and glyoxylate. The function of Ps-NADP-
IDH
seems to be completely discriminated from that of Mt-NAD-IDH as reflected by their distinct subcellular localizations. Furthermore, the properties of Ps-NADP-
IDH
were also compared with those of other mitochondrial and cytosolic IDHs from sources reported previously.
...
PMID:Novel NADP-linked isocitrate dehydrogenase present in peroxisomes of n-alkane-utilizing yeast, Candida tropicalis: comparison with mitochondrial NAD-linked isocitrate dehydrogenase. 771 Mar 26
A 0.6 kb cDNA fragment encoding the human NAD(+)-specific
isocitrate dehydrogenase
alpha-subunit (H-IDH alpha) was amplified by PCR using oligonucleotide primers synthesized on the basis of pig tryptic peptide sequences [Huang and Colman (1990) Biochemistry 29, 8266-8273]. With the amplified cDNA as a probe, cDNA clones for
IDH
alpha were isolated from a human heart lambda gt11 cDNA library. The deduced protein sequence of the largest cDNA clone (2628 bp) rendered a precursor protein of 366 amino acids (39,591 Da) and a mature protein of 339 amino acids (36,640 Da). The deduced H-IDH alpha protein sequence is highly similar to the partial peptide sequences of the pig enzyme. It is 55, 43 and 44% identical with yeast NAD(+)-specific IDH2, yeast NAD(+)-specific IDH1 and monkey NAD(+)-specific
IDH
gamma-subunit (
IDH
gamma) respectively. However, it has less similarity (about 30%) to NADP(+)-specific
IDH
from Escherichia coli and bovine mitochondria. These results indicate that the structure of
IDH
alpha closely resembles that of IDH2, the catalytic subunit of the yeast enzyme. Structural analysis of the deduced H-IDH alpha protein revealed that the amino acids responsible for the binding of isocitrate, Mg2+ and NAD+ are highly conserved. It also has two conserved motifs for the binding sites of ATP and ADP, but a canonical Ca(2+)-binding motif was not recognized. Unusual penta-(ATTTA) and tri-(TAA or ATT) nucleotides which are respectively believed to interact with RNA-binding proteins and be near the endonuclease cleavage sites were frequently recognized in its 3' untranslated region, indicating the possibility of an additional method of regulation of this enzyme. Northern-blot analysis suggests that one mRNA transcript (2.8 kb) exists in cultured HeLa cells. Genomic DNA Southern-blot analysis indicates that the
IDH
alpha gene is not closely related to that of the other
IDH
isoenzymes, and
IDH
alpha appears to be encoded by a single gene.
...
PMID:Characterization of a cDNA clone for human NAD(+)-specific isocitrate dehydrogenase alpha-subunit and structural comparison with its isoenzymes from different species. 775 89
Electrophoretic patterns for
isocitrate dehydrogenase
(
IDH
; EC 1.1.1.42), acid phosphatase (ACP; EC 3.1.3.2), peroxidase (PER; EC 1.11.1.7), and esterase (EST; EC 3.1.1.1) isozymes were determined in Cereus peruvianus tissues and used as markers of genetic uniformity of calli and of the plants regenerated from callus cultures. One
IDH
, six ACP, six PER, and six EST isozymes were induced in cultured callus tissues in medium containing three 2,4-dichlorophenoxyacetic acid and kinetin combinations. Four ACP, two PER, and three EST isozymes were still present in all regenerated plants in vitro and therefore can be used as markers of the C. peruvianus plants regenerated from callus tissues. The differential patterns of ACP and
IDH
isozymes and the similar zymograms for PER and EST isozymes presented by callus tissues were used in a comparison of callus tissues cultured for 2 years. The comparative analysis of zymograms within each enzyme system indicated a mean heterogeneity coefficient of 0.33 for C. peruvianus calli cultured for 2 years. Because of the isozyme variations, which developed in culture medium and were transferred to the regenerated plants, the
IDH
, ACP, PER, and EST enzyme systems can be considered to be good markers for investigating possible genetic variations in plant populations of C. peruvianus obtained in vitro from callus culture.
...
PMID:Isozyme patterns in callus cultures and in plants regenerated from calli of Cereus peruvianus (Cactaceae). 782 11
The three isozymes of
isocitrate dehydrogenase
in Saccharomyces cerevisiae differ in subunit structure, subcellular location, and cofactor specificity. The two mitochondrial isozymes,
IDH
and IDP1, are NAD- and NADP-specific, respectively. Several lines of evidence presented here confirm the importance of
IDH
to respiratory processes. Expression of
IDH
RNA and protein is low with growth on glucose and is elevated with growth on non-fermentable carbon sources, a pattern of expression similar to that seen for other tricarboxylic acid cycle enzymes. In addition, a disruption mutant lacking
IDH
activity exhibits reduced growth rates on non-fermentable carbon sources, and mitochondria isolated from this mutant are incapable of respiration with added citrate. In contrast, IDP1 expression levels appear to be unresponsive to carbon source, and an IDP1 disruption mutant is not significantly impaired for growth or mitochondrial respiration. These results strongly suggest that IDP1 is incapable of participating in tricarboxylic acid cycle-based respiration despite its mitochondrial location. Analysis of the IDP1 and
IDH
disruption mutants for glutamate auxotrophy showed that either enzyme can contribute alpha-ketoglutarate for endogenous glutamate synthesis.
IDH
expression levels were found to be repressed in response to added glutamate during growth on glucose, while IDP1 expression levels remained unchanged. A double mutant lacking both IDP1 and
IDH
activities proved to be auxotrophic for glutamate during growth on glucose, but was capable of growth independent of added glutamate on non-fermentable carbon sources. These results suggest that the cytosolic NADP-specific IDP2 isozyme may provide alpha-ketoglutarate both for tricarboxylic acid cycle carbon flux and for cytosolic glutamate synthesis during growth on non-fermentable carbon sources in the absence of mitochondrial
isocitrate dehydrogenase
activity.
...
PMID:Function and expression of yeast mitochondrial NAD- and NADP-specific isocitrate dehydrogenases. 809 57
NADP(+)-
isocitrate dehydrogenase
(NADP(+)-IDH) from the dinitrogen-fixing filamentous cyanobacterium Anabaena sp. strain PCC 7120 was purified to homogeneity. The native enzyme is composed of two identical subunits (M(r), 57,000) and cross-reacts with antibodies obtained against the previously purified NADP(+)-IDH from the unicellular cyanobacterium Synechocystis sp. strain PCC 6803. Anabaena NADP(+)-IDH resembles in its physicochemical and kinetic parameters the typical dimeric IDHs from prokaryotes. The gene encoding Anabaena NADP(+)-IDH was cloned by complementation of an Escherichia coli icd mutant with an Anabaena genomic library. The complementing DNA was located on a 6-kb fragment. It encodes an NADP(+)-IDH that has the same mobility as that of Anabaena NADP(+)-IDH on nondenaturing polyacrylamide gels. The icd gene was subcloned and sequenced. Translation of the nucleotide sequence gave a polypeptide of 473 amino acids that showed high sequence similarity to the E. coli enzyme (59% identity) and with IDH1 and IDH2, the two subunits of the heteromultimeric NAD(+)-
IDH
from Saccharomyces cerevisiae (30 to 35% identity); however, a low level of similarity to NADP(+)-IDHs of eukaryotic origin was found (23% identity). Furthermore, Anabaena NADP(+)-IDH contains a 44-residue amino acid sequence in its central region that is absent in the other IDHs so far sequenced. Attempts to generate icd mutants by insertional mutagenesis were unsuccessful, suggesting an essential role of
IDH
in Anabaena sp. strain PCC 7120.
...
PMID:NADP(+)-isocitrate dehydrogenase from the cyanobacterium Anabaena sp. strain PCC 7120: purification and characterization of the enzyme and cloning, sequencing, and disruption of the icd gene. 816 22
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