Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infective (L3) larvae of Strongyloides ratti (homogonic strain) were freeze-clamped (-196 degrees C) and the steady-state content of the glycolytic, Krebs tricarboxylic acid (KTA)-cycle intermediates and adenine nucleotides analysed. Comparison of the mass-action ratios (MARs) of the glycolytic enzymes with their apparent equilibrium constants (K9eq) indicate that phosphoglucomutase, glucosephosphate isomerase, triosephosphate isomerase, phosphoglyceromutase and phosphopyruvate hydratase reactions were all at or near equilibrium, whilst hexokinase, phosphofructokinase and pyruvate kinase were displaced from equilibrium. The S. ratti aldolase and myokinase appear to be somewhat displaced from equilibrium and thus may have pseudoregulatory roles. The adenylate energy charge (AEC), ATP/ADP ratio and the available adenylate energy (AAE) indices were 0.9 +/- 0.04, 8.76 +/- 1.5 and 397 +/- 43, respectively. The free [NAD+]/[NADH+H+] ratio of the cytoplasmic compartment of S. ratti L3 larvae calculated employing the steady-state content of the oxidised and reduced substrates of lactate dehydrogenase (E.C. 1.1.1.27) and the combined glyceraldehyde 3-phosphate dehydrogenase (E.C. 1.2.1.12)/3-phosphoglycerate kinase (E.C. 2.7.2.3) system were ca. 523 and 1200, respectively. The free[NAD+]/[NADH+H+] ratio in the mitochondrial compartment of S. ratti L3 larvae calculated using the malate dehydrogenase (E.C. 1.1.1.37) equilibrium was found to be 1962:1. The data is discussed with respect to the predominantly aerobic nature of the energy metabolism of the L3 larvae.
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PMID:Steady-state content of glycolytic/tricarboxylic acid-cycle intermediates, adenine nucleotide pools and the cellular redox-status in the infective (L3) larvae of (homogonic) Strongyloides ratti. 762 25

The chlortetracycline fluorescence assay was used to study the status of capacitation and the extent of induced acrosome reactions in cauda epididymidal spermatozoa from fertile and infertile rats fed, respectively, with vehicle or ornidazole (400 mg kg-1 day-1) for 10 days. Uniform bright fluorescence over the whole head was classified as the uncapacitated pattern, whereas a postacrosomal dark band, and a uniformly weaker fluorescence over the acrosome, reflected patterns intermediate between the uncapacitated and acrosome-reacted states. Acrosome-reacted spermatozoa displayed a dark head but always retained fluorescence at their tip. There was no difference between experimental and control groups of rats with regard to the development of the chlortetracycline fluorescence patterns during incubation. Under basal incubation conditions, the acrosome reaction was slightly delayed in spermatozoa from ornidazole-treated animals. In contrast, more spermatozoa were acrosome reacted in this group after incubation for 5 h when the concentration of BSA was increased from 4 to 20 mg ml-1. The Ca(2+)-ionophore A23187 induced a similar stimulation of capacitation and acrosome reactions in spermatozoa from control and ornidazole-fed animals, but in the latter group A23187 caused strong immobilization of spermatozoa. In the capacitation medium containing 5 mmol lactate l-1 and 5 mmol glucose l-1, the straight-line velocity of spermatozoa from ornidazole-treated rats was reduced by 50% compared with controls, irrespective of the concentration of BSA. Two glycolytic enzymes, triose phosphate isomerase and glyceraldehyde 3-phosphate dehydrogenase, displayed reduced activity (48% and 68% of controls, respectively) in cauda epididymidal spermatozoa from ornidazole-fed rats, whereas the activities of hexokinase and lactate dehydrogenase remained unchanged. This finding suggests that the fertility-compromising action of ornidazole is due to a disturbed glycolytic pathway.
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PMID:Influence of oral administration of ornidazole on capacitation and the activity of some glycolytic enzymes of rat spermatozoa. 869 6

The presence of 14 enzymes was investigated using purified spores of the microsporidian Nosema grylli from fat body of the crickets Gryllus bimaculatus. Glucose 6-phosphate dehydrogenase (EC 1.1.1.49), phosphoglucomutase (EC 5.4.2.2), phosphoglucose isomerase (EC 5.3.1.9), fructose 6-phosphate kinase (EC 2.7.1.11), aldolase (EC 4.1.2.13), 3-phosophoglycerate kinase (EC 2.7.2.3), pyruvate kinase (EC 2.7.1.40) and glycerol 3-phosphate dehydrogenase (EC 1.1.1.8) were detected with activities of 15 +/- 1, 7 +/- 1, 1,549 +/- 255, 10 +/- 1, 5 +/- 1, 16 +/- 4, 6 +/- 1 and 16 +/- 2 nmol/min mg protein, respectively. Hexokinase (EC 2.7.1.1), NAD-dependent malate dehydrogenase (EC 1.1.1.37), malic enzyme (EC 1.1.1.40), lactate dehydrogenase (EC 1.1.1.27), alcohol dehydrogenase (EC 1.1.1.1) and succinate dehydrogenase (EC 1.3.99.1) were not detectable. These results suggest the catabolism of carbohydrates in microsporidia occurs via the Embden-Meyerhof pathway. Glycerol 3-phosphate dehydrogenase may reoxidize NADH which is produced by glyceraldehyde 3-phosphate dehydrogenase in glycolysis.
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PMID:Activities of enzymes of carbohydrate and energy metabolism of the spores of the microsporidian, Nosema grylli. 918 13

Huntington disease (HD) fibroblasts subjected to stress exhibit an enzyme profile that is different from that exhibited by escapee (unaffected members of families with HD) or control fibroblasts. The specific activity of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in normally cultured HD fibroblasts was not different from that in control and escapee fibroblasts. However, in escapee and control fibroblasts subjected to stress by withholding fresh medium, the specific activity of GAPDH in cells harvested by trypsinization increased greatly 3 weeks after withholding medium ( approximately 8-fold), but the increase was significantly less pronounced ( approximately 3-fold) in the HD fibroblasts. In contrast, only small changes occurred in the specific activity of lipoamide dehydrogenase (LADH) over the same time period, and the values were not significantly different among the three groups at any time point. The specific activity of hexokinase (HK) was significantly higher in the HD fibroblasts at 1-3 weeks after withholding fresh medium than in the escapee/control fibroblasts. Finally, the total yield of fibroblasts per culture flask (as judged by protein content) was significantly greater for the stressed HD fibroblasts than for the escapee and control fibroblasts at 2 and 3 weeks after withholding medium. The present results are in accord with the hypothesis that HD is a disease associated with latent, generalized metabolic abnormalities.
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PMID:Glyceraldehyde 3-phosphate dehydrogenase abnormality in metabolically stressed Huntington disease fibroblasts. 977 85

Oval cells are liver epithelial cells that proliferate during the early stages of hepatocarcinogenesis induced by a variety of chemicals. The oval cell lines OC/CDE 6 and OC/CDE 22 have been established in our laboratory at two time points (6 and 22 weeks) of the carcinogenic process and have been malignantly transformed by different procedures. During the transformation process, the glycolytic and glutaminolytic flux rates were consistently up-regulated and this process was accompanied by an overproportional increase in the activities of cytosolic hexokinase and 6-phosphogluconate dehydrogenase. In transformed oval cells, a strong correlation between the glycolytic flux rate and glutamine consumption as well as glutamate production was observed. Furthermore, the transport of glycolytic hydrogen, produced by the glyceraldehyde 3-phosphate dehydrogenase-catalyzed reaction, from the cytosol into the mitochondria by means of the malate-aspartate shuttle was enhanced, this being due to alterations in the activities of malate dehydrogenase and glutamate oxaloacetate transaminase. The up-regulation of the glycolytic hydrogen transport and the alterations in the glycolytic enzyme complex led to an enhanced pyruvate production at high glycolytic flux rates. Taken together, our data are further proof that a special metabolic feature (increased glycolysis and glutaminolysis) is characteristic for tumor cells and that the mechanisms by which this metabolic state is induced can be totally different.
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PMID:Alterations in the glycolytic and glutaminolytic pathways after malignant transformation of rat liver oval cells. 1045 61

Aerobic exercise training evokes adaptations in the myocardial contractile machinery that enhance cardiac functional capacity; in comparison, the effects of training on the myocardium's energy generating pathways are less well characterized. This study tested the hypothesis that aerobic exercise training can increase the capacities of the major pathways of intermediary metabolism in canine myocardium. Mongrel dogs were conditioned by a 9-week treadmill running program or cage rested for 4 weeks. Exercise conditioning was evidenced by 26% and 22% decreases (P<0.05) in respective heart rates at rest and during submaximal exercise and by a 40% increase (P<0.05) in citrate synthase (CS) activity of the vastus lateralis. Glycolytic, TCA cycle, and beta-oxidative enzymes were assayed in myocardial extracts at 37 degrees C. Relative to sedentary controls, training increased glyceraldehyde 3-phosphate dehydrogenase (GAPDH) activity by 49% in left and 33% in right ventricle, and pyruvate kinase, CS, and 3-hydroxyacyl CoA dehydrogenase (HADH) activities by 74%, 91%, and 77%, respectively, in left ventricle (P<0.05). Immunoblotting further confirmed that training increased left ventricular contents of CS and GAPDH. Other measured enzymes (hexokinase, phosphofructokinase, lactate dehydrogenase, alpha-ketoglutarate dehydrogenase, malate dehydrogenase) were not altered by training in either ventricle. Kinetic analyses revealed increased maximum rates but unaltered substrate affinities of GAPDH, CS and HADH following training. Thus, aerobic exercise training augments the intermediary metabolic capacity of canine myocardium by selectively increasing the concentrations of regulatory enzymes of glycolysis and oxidative metabolism.
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PMID:Exercise training enhances glycolytic and oxidative enzymes in canine ventricular myocardium. 1088 45

S. cerevisiae responds to the presence of amino acids in the environment through the membrane-bound complex SPS, by altering transcription of several genes. Global transcription analysis shows that 46 genes are induced by L-citrulline. Under the given conditions there appears to be only one pathway for induction with L-citrulline, and this pathway is completely dependent on the SPS component, Ssy1p, and either of the transcription factors, Stp1p and Stp2p. Besides the effects on amino acid permease genes, an ssy1 and an stp1 stp2 mutant exhibit a number of other transcriptional phenotypes, such as increased expression of genes subject to nitrogen catabolite repression and genes involved in stress response. A group of genes involved in the upper part of the glycolysis, including those encoding hexose transporters Hxt4p, Hxt5p, Hxt6p, Hxt7p, hexokinase Hxk1p, glyceraldehyde 3-phosphate dehydrogenase Tdh1p and glucokinase (Glk1p), shows increased transcription levels in either or both of the mutants. Also, most of the structural genes involved in trehalose and glycogen synthesis and a few genes in the glyoxylate cycle and the pentose phosphate pathway are derepressed in the ssy1 and stp1 stp2 strains.
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PMID:Transcriptional profiling of extracellular amino acid sensing in Saccharomyces cerevisiae and the role of Stp1p and Stp2p. 1519 29

The effects of the sodium nitroprusside (SNP), a nitric oxide (NO) donor clinically used in the treatment of hypertensive emergencies on the energy production of rat reticulocytes were investigated. Rat reticulocyte-rich red blood cell suspensions were aerobically incubated without (control) or in the presence of different concentrations of SNP (0.1, 0.25, 0.5, 1.0 mM). SNP decreased total and coupled, but increased uncoupled oxygen consumption. This was accompanied by the stimulation of glycolysis, as measured by increased glucose consumption and lactate accumulation. Levels of all glycolytic intermediates indicate stimulation of hexokinase-phosphofructo kinase (HK-PFK), glyceraldehyde 3-phosphate dehydrogenase (GAPD) and pyruvate kinase (PK) activities in the presence of SNP. Due to the decrease of coupled oxygen consumption in the presence of SNP, ATP production via oxidative phosphorylation was significantly diminished. Simultaneous increase of glycolytic ATP production was not enough to provide constant ATP production. In addition, SNP significantly decreased ATP level, which was accompanied with increased ADP and AMP levels. However, the level of total adenine nucleotides was significantly lower, which was the consequence of increased catabolism of adenine nucleotides (increased hypoxanthine level). ATP/ADP ratio and adenylate energy charge level were significantly decreased. In conclusion, SNP induced inhibition of oxidative phosphorylation, stimulation of glycolysis, but depletion of total energy production in rat reticulocytes. These alterations were accompanied with instability of energy status.
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PMID:Effects of exogenous donor of nitric oxide-sodium nitroprusside on energy production of rat reticulocytes. 1531 4

Preparations of heterocysts of Anabaena cylindrica Lemm. had 7- to 8-fold higher activities of glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, 2-fold more hexokinase activity, and 0.02 to 0.06 times as much ribulose diphosphate carboxylase and glyceraldehyde 3-phosphate dehydrogenase activities as did whole filaments per milligram soluble protein in cell-free extracts. Time courses of solubilization of glucose 6-phosphate dehydrogenase activity indicated that heterocysts contain 74 to 80% of the total activity of this enzyme in filaments.
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PMID:Activities of enzymes of the oxidative and the reductive pentose phosphate pathways in heterocysts of a blue-green alga. 1665 88

Antibodies to yeast d-glyceraldehyde 3-phosphate dehydrogenase have been produced in rabbits and chickens. The antiserum from either animal inhibits the activity of the yeast enzyme with the formation of a precipitate that has a low residual activity. One combining site of antibody on the enzyme appears to be the point of DPN attachment. The rate of antigen-antibody formation has been studied with varying concentrations of antibody. The activity of yeast hexokinase is not inhibited by the antiserum to the dehydrogenase. Five of six antisera to the yeast enzyme showed no inhibition of the analogous enzyme from rabbit muscle, but one serum strongly inhibited the muscle dehydrogenase in the absence of DPN. No evidence was obtained that the inhibition by this one antiserum was due to an immune reaction, because the inhibition persisted after absorption with the homologous antigen.
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PMID:The inhibition of d-glyceraldehyde 3-phosphate dehydrogenase by specific antiserum. 1810 96


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