Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Small-bore ("Autozyme") tubes with immobilized enzymes at the inner wall have been developed and studied for application in the Technicon "SMAC" high-speed continuous-flow biochemical analyzer. Tubes coated with glucose oxidase (D-glucose:oxygen oxidoreductase, EC 1.1.3.4) have been prepared for the assay of glucose, with colorimetric assay of the hydrogen peroxide produced; tubes coated with glycerol kinase (ATP:glycerol phosphotransferase, EC 2.7.1.30) for the enzymatic assay of triglycerides; tubes coated with hexokinase (ATP:D-hexose-6-phosphotransferase, EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NAD+ oxidoreductase EC 1.1.1.49) for the measurement of ATP, an intermediate product in assays for creatine kinase. With use of 10-15 cm lengths of Autozyme tube and SMAC hydraulics (150 samples per hour), assay sensitivity and carryover were similar to values for the corresponding free-enzyme methods. These immobilized enzymes were sufficiently stable for one to eight weeks of continuous use before replacemnt. We conclude that suitable bound-enzyme tubes can replace either single or multiple free-enzyme reagents in many continuous-flow assays at high sampling rates.
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PMID:Continuous-flow analysis for glucose, triglycerides, and ATP with immobilized enzymes in tubular form. 1 65

The 3T3-L1 mouse fibroblast cell line develops morphological and biochemical characteristics of adipocytes when maintained at confluence. This conversion to adipocytes is accelerated by addition of insulin to the culture medium [Green, H. & Kehinde, O. (1975) Cell 5, 19-27]. During the course of the insulin-mediated adipocyte conversion, the specific activity (units/mg of protein) of glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] increases more than 100-fold. The specific activities of hexokinase (ATP:D-hexose 6-phosphotransferase, EC 2.7.1.1) and glucose-6-P dehydrogenase (D-glucose-6-phosphate:NADP(+) 1-oxidoreductase, EC 1.1.1.49) also increase but less dramatically (1.5- to 3-fold). In contrast, confluent cells maintained in the absence of insulin for the same time (12-20 days after confluence) display only minimal increases in the activity of these enzymes. Maintenance of confluent cells in culture medium lacking added L-glutamine has little, if any, effect on glutamine synthetase activity in either control or insulin-treated cultures. Treatment of confluent 3T3-L1 cultures with hydrocortisone (1 mug/ml) for 3 days prior to harvesting results in an increase in glutamine synthetase specific activity of 12-fold for control cultures maintained for 13 days in the absence of insulin and 1.4-fold for adipocyte cultures maintained for 13 days in the presence of insulin (10 mug/ml). Treatment of 3T3-L1 control cells and adipocytes with dibutyryl cyclic AMP (1 mM) plus theophylline (1 mM) decreases the glutamine synthetase specific activity and almost completely reverses the insulin- and hydrocortisone-mediated increases in enzyme activity. In contrast, treatment with dibutyryl cyclic AMP plus theophylline has relatively little effect on the specific activities of hexokinase or glucose-6-P dehydrogenase or on the protein content of the cultures. These data indicate that glutamine synthetase activity is hormonally regulated in 3T3-L1 cells.
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PMID:Regulation of glutamine synthetase in cultured 3T3-L1 cells by insulin, hydrocortisone, and dibutyryl cyclic AMP. 2 55

Bacterial luciferase and NADH:FMN oxidoreductase have been immobilized onto arylamine glass beads. These immobilized enzymes can detect as little as 0.2 pmol of NADH per assay sample. Glucose-6-phosphate dehydrogenase has been co-immobilized with these enzymes, and with this system it is possible to quantitate 1 pmol of glucose 6-phosphate. By co-immobilizing a fourth enzyme, hexokinase, onto the glass beads, the system can reproducibly detect 20 pmol of glucose per liter. These immobilized enzyme systems are potentially superior to soluble enzymes by being reusable and much more stable. We compared the light-emitting properties of the immobilized enzyme systems with that of an equivalent mixture of the soluble enzymes. The most striking difference was the apparently more efficient conversion of NADH or glucose 6-phosphate to light by the immobilized enzymes. We used hydroxysteroid dehydrogenase in developing a soluble coupled system for the assay of androsterone and testosterone. The lower limit of detection was 100 pmol.
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PMID:Properties and uses of immobilized light-emitting enzyme systems from Beneckea harveyi. 3 21

The growth of Brucella abortus (US-19) in a complex tryptose-yeast extract medium containing D-glucose is inhibited by 10 mM erythritol. The enzymes of the erythritol pathway, except for D-erythrulose 1-phosphate dehydrogenase (D-glycero-2-tetrulose 1-phosphate:nicotinamide adenine dinucleotide (NAD+) 4-oxidoreductase) were detected in the soluble and membrane fractions of cell extracts. Glucose catabolism by cell extracts was inhibited by erythritol, whereas, phosphorylated intermediates of the hexose monophosphate pathway were converted to pyruvic acid with oxygen consumption. Erythritol kinase (EC 2.7.1.27; adenosine 5'-triphosphate (ATP): erythritol 1-phosphotransferase) was found to be eightfold higher in activity than the hexokinase in cell extracts. In vivo, ATP is apparently consumed with the accumulation of D-erythrulose 1-phosphate (D-glycero-2-tetrulose 1-phosphate) and no substrate level phosphorylation. ATP levels dropped 10-fold in 30 min after addition of erythritol to log phase cells in tryptose-yeast extract medium with D-glucose as the carbon source. These data suggest bacteriostasis in the presence of erythritol results from the ATP drain caused by erythritol kinase.
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PMID:Inhibition of growth by erythritol catabolism in Brucella abortus. 17 Feb 49

The denaturation of eight purified yeast enzymes, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase, alcohol dehydrogenase, beta-fructosidase, hexokinase and glucose-6-phosphate isomerase, promoted under controlled conditions by the free fatty acids myristic and oleic, is selective. Glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NADP+ 1 oxidoreductase, EC 1.1.1.49) is extremely sensitive to destabilization and was studied in greater detail. Results show that chain length and degree of unsaturation of fatty acids are important to their destabilizing effect, and that ligands of the enzyme can afford protection. The denaturation process results in more than one altered form. These results can be viewed in the perspective of the possibility that amphipathic substances, and in particular free fatty acids, may play a role for enzyme degradation in vivo, by initiating steps of selective denaturation.
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PMID:Selective denaturation of several yeast enzymes by free fatty acids. 35 87

Detailed histochemical studies have been conducted on the distribution of various enzymes, including thiamine pyrophosphatase, alpha-glucan phosphorylase, hexokinase, glucose-6-phosphate dehydrogenase, aldolase, glycerol-3-phosphate dehydrogenase; menadion oxidoreductase, lactate dehydrogenase and succinate dehydrogenase in various components of the cerebellum of healthy adult male rats of the Wistar strain. The thiamine pyrophosphatase reaction showed the morphological patterns of the GOLGI apparatus characteristic for each kind of cells. The GOLGI apparatus is a simple network in stellate cells, but it can be classified into the same 5 categories in basket cells and GOLGI type II cells. The GOLGI apparatus in the latter 2 cell types appears to undergo cyclic changes. A few GOLGI type II cells have a supranuclear form (Type II) and some cells show disintegration and "budding-off" of the GOLGI apparatus. The GOLGI apparatus in PURKINJE cells can be classified into 4 categories including a perinuclear strand form (Type III), but most of them show randomly distributed granules and vesicles. Lightly stained networks are observable in astrocytes and oligodendrocytes. They do not show polarity in astrocytes whereas they have extensions in a few oligodendrocytes. BERGMANN glia may undergo cyclic changes indicating more advance differentiation than astrocytes and oligodendrocytes. Cerebellar glomerula show lightly stained networks with many fine granules. Granule cells, stellate cells, and basket cells are all poorly equipped equally with the EMBDEN-MEYERHOF (EM) pathway and with the hexosemonophosphate (HMP) shunt. GOLGI type II cells are richly equipped almost equally with both the EM pathway and the HMP shunt. All these neurons probably derive energy mainly from glucose in the circulating blood. PURKINJE cells may belong to the category of "usual neurons", because they are moderately equipped both with the EM pathway and the HMP shunt. However, they may derive their energy from the BERGMANN glia which have intense hexokinase activity but weak succinate dehydrogenase activity. The BERGMANN glia are more richly equipped with the HMP shunt than with the EM pathway and are rich in lactate dehydrogenase suggesting an "exceptional metabolic pattern". These glia may have active synthesizing ability. Astrocytes and oligodendrocytes are equipped with all the enzymes tested, and they show a tendency to surround the glomeruli. It is suggested that the glomerula may be surrounded by the glial sheaths with strong hexokinase activity, and that they may contain alpha-glucan phosphorylase, glucose-6-phosphate dehydrogenase, and glycerol-3-phosphate dehydrogenase in addition to the succinate dehydrogenase already reported. A few PURKINJE cells showed perinuclear concentrations of the reaction product only of succinate dehydrogenase at the sites of contacts between nucleoli and nuclear membranes. It is suggested that the nucleolus may receive adenosine at the sites of contacts between nucleoli and nuclear membranes...
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PMID:Histochemical studies on the morphology of the Golgi apparatus and on the distribution of some enzymes concerned with carbodydrate metabolism in the rat cerebellum. 40 26

In this communication the results of applying various histochemical semipermeable membrane techniques to the localization of several enzymes in bovine and porcine heart are presented. The Purkinje fibers of the atrioventricular conducting system of the bovine heart differ from the myocardium proper in containing a greater activity of the glycolytic and gluconeogenetic enzymes--lactate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, hexokinase, glucosephosphate isomerase and phosphoglucomutase, and less activity of the aerobic enzymes--NADH: nitroBT oxidoreductase and isocitrate dehydrogenase (NADP+). The metabolic reactions obtained with Purkinje fibers of the porcine heart are less pronounced. These histochemical findings are in accordance with the impression that Purkinje fibers, compared with the common myocardial fibers, have a higher rate of anaerobic metabolism and a lower rate of aerobic metabolism. The activity of the NADPH regenerating enzymes glucose-6-phosphate dehydrogenase and phosphogluconate dehydrogenase (decarboxylating), and the activity of acid hydrolases such as non-specific esterase and acid phosphatase is higher in the Purkinje fibers of both the bovine and porcine heart.
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PMID:Enzyme histochemical studies on the Purkinje fibers of the atrioventricular system of the bovine and porcine hearts. 66 82

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6-phosphogluconate dehydrogenase (6-phospho-d-gluconate: NADP oxidoreductase, 6PGD), hexokinase (ATP:D-hexose 6-phosphotransferase, HK), lactic dehydrogeanse (L-lactate: NAD oxidoreductase, LDH) and aspirate aminotransferase (L-aspartate: 2-oxoglutarate aminotransferase, Asp.T) were determined in red blood cells of 11 healthy individuals. The determinations were carried out on samples drawn every 4 h over a 24 h period. The activities of G6PD, 6PGD, LDH and Asp.T exhibited a semi-circadian rhythm, namely, two peaks of activity during 24 h while HK activity demonstrated a true circadian rhythm. In addition a polymorphism of the G6PD and LDH activity patterns was observed. The implications of a biological clock in enucleated cells are discussed.
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PMID:The diurnal rhythm of enzymes in human red cells. 94 47

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6 phosphate glucono dehydrogenase (6 phospho-D-gluconate: NADP oxidoreductase, 6PGD) lactate dehydrogenase (D-lactate: NAD oxidoreductase, LDH), glutamate oxaloacetate transaminase (L-aspartate: 2-oxo-glutarate aminotransferase, GOT) and hexokinase (ATP: D-hexo-6-phosphotrans-ferase, Hx) were measured over 24 h in isolated lymphocytes of normal subjects and in white cells of patients with chronic lymphatic leukaemia (CLL). The activitty patterns of all enzymes in the normal lymphocytes were similar. A computed pattern of all the results exhibited a circadian rhythm of activity with the highest level at 16.00 hours. The oscillations in the activities of the same enzymes in the CLL cells differed among the patients, although all the enzymes of the same individual showed a similar diurnal rhythmic pattern. All peaks in this group appeared between 20.00 and 08.00 hours. The possible importance of these observations in setting up therapeutic schedules was raised.
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PMID:Blood leucocyte enzymes. III. Diurnal rhythm of activity in isolated lymphocytes of normal subjects and chronic lymphatic leukaemia patients. 98 50

The activities of glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate: NADP oxidoreductase, G6PD), 6-phosphogluconate dehydrogenase (6-phospho-D-gluconate: NADP oxidoreductase, 6PGD), hexokinase (ATP: D-hexose 6-phosphotransferase, Hx), lactate dehydrogenase (D-lactate: NAD oxidoreductase, LDH). glutamate oxaloacetate transaminase (L-aspartate: 2 oxoglutarate aminotransferase, GOT) and dihydrofolate reductase (DHFR) were measured at 8 a.m. in leucocytes of healthy individuals and patients with chronic myeloid leukaemia (CML), chronic lymphatic leukaemia (CLL), myelofibrosis with myeloid metaplasia and polycythaemia vera. In view of the heterogeneity of the leucocyte populations in these conditions, the enzyme activities were correlated to the number of immature cells in CML and to the percentage of lymphocytes in CLL. No differences in the enzyme activities were found between the white cells of healthy individuals, myelofibrosis with myeloid metaplasia and polycythaemia vera. In CML the activities of all enzymes except GOT correlated directly with the number of immature cells; an inverse correlation with the number of lymphocytes was observed in CLL. GOT was the only enzyme whose activity correlated with the number of lymphocytes in the cell suspension. Furthermore, a significantly higher activity of this enzyme was found in Ficoll-isolated CLL lymphocytes as compared to normal lymphocytes.
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PMID:Blood leucocyte enzymes. II. Activities at 8-9 a.m. in cells of normal subjects, chronic lymphatic leukaemia and chronic myeloid leukaemia patients. 105 70


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