Purification, properties, and kinetic observations on the isoenzymes of NADP isocitrate dehydrogenase of maize

Curry, Russell A.; Ting, Irwin P.

doi:10.1016/0003-9861(76)90193-4

Cited by 29 publications

(14 citation statements)

References 18 publications

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“…3). During the next 3 hr, activity decreased at 10 C and increased at 23 C. Activities increased rapidly between 6 and 12 hr and then leveled for the duration of the experiment at 10 C. A rapid increase in activity due to axis activity was observed between 24 and 48 hr with the 23 C treatment.…”

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confidence: 82%

“…We found all extractable ICDH activity from mitochondria to be NADP-linked as have others working with legume mitochondria (2). However, there is some controversy over the nature of NADP-ICDH in that some researchers have found a large amount of this enzyme in plant mitochondria (2,6) and others have claimed or implicated that only a small proportion is associated with mitochondria (16).…”

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confidence: 99%

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Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Duke

Schrader²,

Miller³

1977

Plant Physiol.

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The influence of low temperature on soybean (Glycine max [L.] Meff. cv. Wells) energy transduction via mitochondrial respiration and dehydrogenases was investigated in this study during imbibition and germination. Mitochondria were isolated from embryonic axes of seeds treated at 10 and 23 C (control) by submergence in H20 for 6 hours and maintenance for an additional 42 hours in a moist environment.Arrhenius plots of initial respiration rates revealed that those from cold-treated axes had respiratory control (RC) ratios of near 1.0 above an inflection in the plot at 8 C. Arrhenius plots of control axes mitochondrial respiration showed RC rtios of 2.8 above and 5.0 below an inflection temperature of 12.5 C. Energies of activation for mitochondrial respiration between 20 and 30 C for the cold and control treatments were 7.8 and 15.6 kcal/mole, respectively. These data indicate possible differences in mitochondria membranes, degree of mitochondrial integrity, and mitochondrial enzyme complement between the two treatments.Gluhtmate dehydrogenase (GDH), malate dehydrogenase (MDH), adcohol dehydrogenase (ADH), glucose-6-phosphate dehydrogenase (G6P-DH), and NADP-isocitrate dehydrogenase (NADP-ICDH) were sayed from whole seeds and axes (after germination) during the 48 bours of temperature treatments. Activity of these dehydrogenases decased during the first 6 hours with the exception of MDH. After germination at 23 C (48 hours) all five debydrogenases increased in activity. Arrhenius plots of cotyledon debydrogenase activities indicated that one inflection temperature between 6 and 18 C was present for each enzyme assayed. Differences were seen in Arrhenius plots of axes dehydrogenase activities with the two temperature treatments in the cases of GDH and MDH from mitochondrial pellets and with differences in enzyme extraction media. These data suggest that the temperature treatments yield differences in mitochondrial enzyme complement. There were no detectable inflection temperatures for the activities of G6P-DH and ADH extracted from axes. Arrhenius plots of NADP-ICDH activity indicated extreme cold sensitivity. The dopes of the plots for axes NADP-ICDH were very similar to those for mitochondrial respiration (23 C trtment) suggesting that this enzyme may limit mitochondrial respiration at low temperature in soybean tissues grown at moderate temperatures.

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confidence: 82%

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confidence: 99%

Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Duke

Schrader²,

Miller³

1977

Plant Physiol.

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“…1.42). This situation is further complicated by the presence of four ICDH isoenzymes located in different subcellular compartments: the cytosol [21,28], plastids [3,10,14], mitochondria [8,29] and perhaps the peroxisomes [16,34].…”

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confidence: 99%

Identification of a tobacco cDNA encoding a cytosolic NADP-isocitrate dehydrogenase

et al. 1996

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A cDNA which encodes a specific member of the NADP-dependent isocitrate dehydrogenase (ICDH) multi-isoenzyme family has been isolated from a tobacco cell suspension library, and the expression pattern of ICDH transcripts examined in various plant tissues. To assign this cDNA to a specific ICDH isoenzyme, the major, cytosolic ICDH isoenzyme of tobacco leaves (ICDH1) was purified to homogeneity and its N-terminus as well as several tryptic peptides, representing 30% of the protein, were sequenced. The comparison of these amino acid sequences with the deduced protein sequence of the cDNA confirmed that this clone encodes for ICDH1. The total ICDH specific activity and protein content were higher in vascular-enriched tobacco leaf tissue than in deveined (depleted in midrib and first-order veins) leaves. Taking advantage of antibodies raised against either ICDH1 or the chloroplastic ICDH2 isoenzyme from tobacco cell suspensions, an immuno-cytochemical approach indicated that the ICDH1 isoenzyme, located in the cytosolic compartment of tobacco leaf cells, is responsible for this expression pattern. This observation was confirmed by northern blot analyses, using a specific probe obtained from the 3' non-coding region of the ICDH1 cDNA. A comparison of ICDH protein sequences shows a large degree of similarity between eukaryotes (> 60%) but a poor homology is observed when compared to Escherichia coli ICDH (< 20%). However, it was found that the amino acids implicated in substrate binding, deduced from the 3-dimensional structure of the E. coli NADP-ICDH, appear to be conserved in all the deduced eukaryotic ICDH proteins reported until now.

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“…It is present in plant cytosol (5,8,15,18), mitochondria (1,5), and chloroplasts (7,11), thus indicating that it may have varying roles in the metabolism ofthe plant. The chloroplastic form of NADP+-IDH is believed to supply 2-oxoglutarate for glutamate synthesis (7), while the cytosolic enzyme probably functions in the transfer of reducing power between the mitochondria and cytosol (12).…”

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confidence: 99%

“…The chloroplastic form of NADP+-IDH is believed to supply 2-oxoglutarate for glutamate synthesis (7), while the cytosolic enzyme probably functions in the transfer of reducing power between the mitochondria and cytosol (12). In addition to the various bacterial and mammalian species, this enzyme has been well studied from a number of plant sources ' including etiolated seedlings (16), leaves (15,18), germinating (21) and maturing seeds (5,20), and root nodules (8).…”

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confidence: 99%

Partial Purification and Characterization of NADP⁺-Isocitrate Dehydrogenase from Immature Pod Walls of Chickpea (Cicer arietinum L.)

Gupta¹,

Singh²

1988

Plant Physiol.

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NADP'-isocitrate dehydrogenase (threo-DS-isocitrate: NADP' oxidoreductase [decarboxylating]; EC 1.1.1.42) (IDH) from pod walls of chickpea (Cicer arietinum L.) was purified 192-fold using ammonium sulfate fractionation, ion exchange chromatography on DEAE-Sephadex A-50, and gel filtration through Sephadex G-200. The purified enzyme, having a molecular weight of about 126,000, exhibited a broad pH optima from 8.0 to 8.6. It was quite stable at 4°C and had an absolute requirement for a divalent cation, either Mg2" or Mn2, for its activity. Typical hyperbolic kinetics was obtained with increasing concentrations of NADP', DL-isocitrate, Mn2+, and Mg2+. Their K,. values were 15, 110, 15, and 192 micromolar, respectively. The enzyme activity was inhibited by sulfhydryl reagents. Various amino acids, amides, organic acids, nucleotides, each at a concentration of 5 millimolar, had no effect on the activity of the enzyme. The activity was not influenced by adenylate energy charge but decreased linearly with increasing ratio of NADPH to NADP+. Initial velocity studies indicated kinetic mechanism to be sequential. NADPH inhibited the forward reaction competitively with respect to NADP+ at fixed saturating concentration of isocitrate, whereas 2-oxoglutarate inhibited the enzyme noncompetitively at saturating concentrations of both NADP+ and isocitrate, indicating the reaction mechanism to be random sequential. Results suggest that the activity of NADP+-IDH in situ is likely to be controlled by intracellular NADPH to NADP+ ratio as well as by the concentration of various substrates and products.

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Purification, properties, and kinetic observations on the isoenzymes of NADP isocitrate dehydrogenase of maize

Cited by 29 publications

References 18 publications

Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Identification of a tobacco cDNA encoding a cytosolic NADP-isocitrate dehydrogenase

Partial Purification and Characterization of NADP⁺-Isocitrate Dehydrogenase from Immature Pod Walls of Chickpea (Cicer arietinum L.)

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Purification, properties, and kinetic observations on the isoenzymes of NADP isocitrate dehydrogenase of maize

Cited by 29 publications

References 18 publications

Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Low Temperature Effects on Soybean (Glycine max [L.] Merr. cv. Wells) Mitochondrial Respiration and Several Dehydrogenases during Imbibition and Germination

Identification of a tobacco cDNA encoding a cytosolic NADP-isocitrate dehydrogenase

Partial Purification and Characterization of NADP+-Isocitrate Dehydrogenase from Immature Pod Walls of Chickpea (Cicer arietinum L.)

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Partial Purification and Characterization of NADP⁺-Isocitrate Dehydrogenase from Immature Pod Walls of Chickpea (Cicer arietinum L.)