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)

Effect of N-trichloromethylthio-4-cyclohexane-1,2-dicarboximide (NTCD) on energy-yielding and energy-requiring processes in Ehrlich ascites carcinoma (EAC) cells have been investigated. At concentrations higher than 10 micrograms/ml NTCD causes a rapid and practically full inhibition of both aerobic glucose uptake and lactate formation. On the other hand, at concentrations lower than 10 micrograms/ml, these metabolic parameters are stimulated. The stimulation of glycolysis, according to our previous results, suggests the interference of NTCD with mitochondrial functions. This image is supported by the marked inhibitory effect on NTCD on respiration of isolated mitochondria. The inhibition of glycolysis with higher concentrations of NTCD is the consequence of inactivation of hexokinase (EC 2.7.1.1), eventually of 6-phosphofructokinase (FC 2.7.1.11). The described effects of NTCD are given into coherence with chemical modification of appropriate functional SH groups of EAC cells by the compound studied. Proportionally to the dose and time NTCD inhibits the synthesis of macromolecules in whole EAC cells as measured by the incorporation of labeled adenine and valine into the TCA-insoluble fractions. The inhibition of biosynthetic processes followed is the consequence of exclusion of key processes in the energy metabolism and leads to the loss of EAC cells transplantability.
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PMID:Cytostatic activity and metabolic effect of N-trichloromethylthio-4-cyclohexane-1,2-dicarboximide on Ehrlich ascites carcinoma cells. 621 71

The maximum activity of the key glycolytic enzymes, hexokinase and 6-phosphofructokinase, was measured in tissues of control and cold-acclimated rats. The only significant change in activity was seen in brown adipose tissue where the activity of these enzymes was increased 2-fold. This increase in glycolytic capacity along with the hypertrophy of BAT observed in cold acclimation suggests that this tissue could play an important role in glucose utilisation by the rat.
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PMID:The maximum capacity of glycolysis in brown adipose tissue and its relationship to control of the blood glucose concentration. 621 86

Adult female rats were subjected to an eleven-week endurance-training programme, and, for the first time, the maximum activities of enzymes that can indicate the quantitative capacities of both anaerobic glycolysis and the Krebs cycle in muscle (viz. 6-phosphofructokinase and oxoglutarate dehydrogenase respectively) were measured in heart plus white and fast-oxidative skeletal muscle. No changes were observed in heart muscle. In fast-oxidative skeletal muscle, activities of hexokinase, citrate synthase, and oxoglutarate dehydrogenase were increased by 51, 26, and 33% respectively but there was no effect on 6-phosphofructokinase. These results demonstrate that in red muscle there is no effect of this training programme on the anaerobic capacity but that of the aerobic system is increased by one third. In white skeletal muscle, only the activity of citrate synthase was increased, which indicates that this activity may not provide even qualitative information about changes in capacity of the Krebs cycle.
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PMID:The effect of endurance-training on the maximum activities of hexokinase, 6-phosphofructokinase, citrate synthase, and oxoglutarate dehydrogenase in red and white muscles of the rat. 622 45

The effect of adrenalectomy on specific activities of testicular hexokinase, 6-phosphofructokinase, pyruvate kinase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glycogen concentration have been studied. A general increase in specific activities of all enzymes was seen after adrenalectomy in rats of all ages studied. However, lactate dehydrogenase activity and glycogen concentration in pre-pubertal rats alone were depleted with no alteration in pubertal and adult animals. This was accompanied by increased prolactin titres, but gonadotrophins and testosterone were unaltered. Dexamethasone treatment returned all enzyme activities and hormonal profiles to normal.
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PMID:Effect of adrenalectomy and dexamethasone treatment on testicular enzymes involved in carbohydrate metabolism. 630 9

The effect of adrenalectomy and corticosterone replacement on epididymal enzymes involved in obligatory steps of glycolysis and pentose phosphate pathway were studied along with serum hormonal profiles. Adrenalectomy was found to elevate serum prolactin while the gonadotropins and testosterone were unaltered. In caput epididymal tissue enzymes of the pentose phosphate pathway. Glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities were increased after adrenalectomy. However, in corpus epididymal tissue the key enzymes viz. hexokinase, 6-phosphofructokinase and pyruvatekinase of the glycolytic pathway were elevated leaving the pentose phosphate pathway unaffected. Adrenalectomy was also found to favour glycolysis of the epididymal spermatozoa. The possible direct effect of prolactin is discussed to explain the enzymatic changes in epididymis. Corticosterone replacement was found to maintain the enzyme activities along with serum prolactin and corticosterone at control levels. In conclusion, it is suggested that the adrenalectomy induced changes in enzyme activities could be due to the direct effect of prolactin.
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PMID:Effect of adrenalectomy and corticosterone replacement on epididymal carbohydrate metabolism--studies on mature male rats. 640 94

Intracellular enzymes in erythrocytes can be made accessible for in situ kinetic studies by treating the cells with bifunctional reagents to crosslink proteins, thus creating a network that allows subsequent permeabilization by delipidation without escape of intracellular proteins. Dimethyl suberimidate, dimethyl 3,3'-dithiobispropionimidate, and toluene-2,4-diisocyanate have been used successfully as crosslinking reagents, and digitonin has been used for delipidation. In a systematic study of the in situ behavior of the 11 glycolytic enzymes of rat erythrocytes, it was observed that Km and Vmax values for the majority of the enzymes are essentially the same in situ as in vitro. Lactate dehydrogenase (L-lactate:NAD+ oxidoreductase, EC 1.1.1.27) is inhibited by excess of pyruvate as much in situ as in vitro. Hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) was allosterically inhibited by glucose 6-phosphate nearly as much in situ as in vitro but was not affected by 2,3-biphosphoglycerate. The allosteric properties of 6-phosphofructokinase (ATP:D-fructose 6-phosphate 1-phosphotransferase, EC 2.7.1.11), glyceraldehyde-phosphate dehydrogenase [D-glyceraldehyde-3-phosphate:NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12], and pyruvate kinase (ATP: pyruvate 2-O-phosphotransferase, EC 2.7.1.40) in situ were qualitatively similar to those observed in vitro, but some important quantitative differences were noticed. Particularly striking was the much greater activity of phosphofructokinase in situ compared to that in vitro at physiological concentrations of effector metabolites.
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PMID:Permeabilization of animal cells for kinetic studies of intracellular enzymes: in situ behavior of the glycolytic enzymes of erythrocytes. 645 Apr 16

Cytotoxic effect of dactylarin on Ehrlich ascites carcinoma cells is caused by the inhibition of some SH-dependent glycolytic enzymes, especially of hexokinase (EC 2.7.1.1), glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) and 6-phosphofructokinase (EC 2.7.1.11). Dactylarin interacts with thiols, which explains its inhibitory effectiveness on the above glycolytic enzymes.
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PMID:Interaction of cytotoxic antibiotic dactylarin with glycolytic thiol enzymes in Ehrlich ascites carcinoma cells. 645 51

The influence of thyroxine on some of the key enzymes involved in glycolytic and pentose phosphate pathways in the testes of pre-pubertal; pubertal and adult rats was studied. Thyroxine-induced (25 micrograms/100 g body weight) hyperthyroidism for 1 month resulted in no change in either hexokinase (EC 2.7.1.1) or 6-phosphofructokinase (EC 2.7.1.11) activity in the testes of rats in any age group studied. However, pyruvate kinase (EC 2.7.1.40) activity was reduced significantly in the pre-pubertal and pubertal rats. Both glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) activities were markedly increased after thyroxine treatment. Withdrawal of hormone treatment resulted in reversion of enzyme activities towards normal. The results suggest that thyroxine has an age-dependent, specific effect over testicular pyruvate kinase activity. Thyroid hormone may have a direct control over the pentose phosphate pathway in the testis.
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PMID:Specific effect of thyroid hormone on testicular enzymes involved in carbohydrate metabolism. II. Hyperthyroidism. 646 78

Isolated incubated lymphocytes utilized acetoacetate, 3-hydroxybutyrate or oleate at about 0.5 mumol/min per g dry wt. These rates were not markedly affected by concanavalin A or by starvation of the donor animal. When ketone bodies replaced glucose in the culture medium, they could not support lymphocyte proliferation when cells were cultured for 48 h. Addition of oleate (0.5 mM) to isolated lymphocytes increased the rate of O2 consumption markedly, suggesting that it could contribute about 30% to O2 consumption. The rate of oleate uptake and the stimulated rate of O2 consumption were maximal at 0.5 M-oleate; this is in contrast with the effect in some other tissues, in which the rate of fatty acid oxidation is linear with concentration up to about 2 mM. Since the normal plasma concentration of fatty acid in the fed state is about 0.5 mM, this suggests that lymphocytes can utilize fatty acids at a maximal rate in the fed state. Ketone bodies or oleate decreased the rate of glucose utilization by incubated lymphocytes; ketone bodies decreased the rate of pyruvate oxidation and increased the intracellular concentration of hexose monophosphate and citrate, suggesting that 6-phosphofructokinase is inhibited by citrate, and hexokinase by glucose 6-phosphate. These effects may be important not so much in conserving glucose in the whole animal but in maintaining the concentrations of glycolytic intermediates necessary for biosynthetic processes during proliferation.
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PMID:Metabolism of ketone bodies, oleate and glucose in lymphocytes of the rat. 646 15

A method is presented for the simultaneous purification of hexokinase, fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase, and the partial purification of glycerol-3-phosphate dehydrogenase (NAD+), 6-phosphofructokinase, glucosephosphate isomerase, and glycerol kinase from Trypanosoma brucei. As a first step, the glycosomes, microbody-like organelles of Trypanosomatidae, containing almost exclusively enzymes involved in glucose and glycerol metabolism [Opperdoes, F. R. and Borst, P. (1977) FEBS Lett. 80, 360-364], were purified eightfold from homogenates with an average yield of 38%. Subsequently, the glycosomal content was subjected to hydrophobic interaction chromatography on phenyl-Sepharose. This step results in pure hexokinase (15% final yield) and almost pure triosephosphate isomerase, while the other glycosomal enzymes elute as mixtures of two or three enzymes. Triosephosphate isomerase was further purified to homogeneity on CM-cellulose (33% final yield), while phosphoglycerate kinase and fructose-bisphosphate aldolase were separated from each other and purified to homogeneity by affinity chromatography using ATP-Sepharose (25% and 30% final yields, respectively). Fructose-bisphosphate aldolase was further characterized as a typical class I enzyme.
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PMID:Simultaneous purification of hexokinase, class-I fructose-bisphosphate aldolase, triosephosphate isomerase and phosphoglycerate kinase from Trypanosoma brucei. 648 38


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