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)

Haemoglobin fractions and 16 enzymatic activities of red cells of a patient with juvenile chronic myeloid leukaemia are compared to normal, to comparably reticulocyte-rich, non-neonatal and to fetal red cells. The activities of hexokinase, triosephosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, monophosphoglyceromutase, enolase and glucose-6-phosphate dehydrogenase are significantly increased in fetal red cells beyond the activities of cell populations with comparable reticulocytosis. The activities of these enzymes are also increased in the patient's erythrocytes. Together with a haemoglobin F concentration of 54% and a concentration of haemoglobin Bart's of 1% these variations reflect the fetal nature of the red cells. Simultaneously, signs of dyserythropoiesis are found in the red cells of the patient: a very high activity of hexokinase and a low pyruvate kinase activity.
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PMID:Fetal erythropoiesis and dyserythropoiesis in juvenile chronic myeloid leukaemia. 82 74

1. The effects of protein concentration and ionic strength on the adsorption of the individual glycolytic enzymes to F-actin and F-actin--trypomyosin--troponin have been studied. 2. Appreciable association was demonstrated under conditions of physiological ionic strength and high protein concentration, and tropomyosin--troponin established as an important and generalized component of these interactions. 3. Phosphofructokinase, aldolase, pyruvate kinase, lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate isomerase were strongly bound under these conditions, while triosephosphate isomerase, phosphoglycerate kinase, phosphoglycerate mutase, enolase and hexokinase displayed less adsorption to the structural proteins. 4. The influence of a number of parameters on the adsorption phenomena was examined. Ca2+ and fructose 1,6-diphosphate increased the adsorption of aldolase, lactate dehydrogenase and pyruvate kinase, while decreasing the adsorption of the enzymes of the constant-proportion group. 5. Of the other major enzymic components of skeletal muscle, creatine kinase, adenylate kinase and malate dehydrogenase showed no adsorption to F-actin--tropomyosin--troponin under the experimental conditions. Some adsorption was evident, however, in the case of aspartate aminotransferase, (NADP) isocitrate dehydrogenase and alpha-glycerolphosphate dehydrogenase. 6. These results have been discussed in relation to their functional significance and the roles of enzyme compartmentation in the cell.
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PMID:On the association of glycolytic enzymes with structural proteins of skeletal muscle. 111 88

The 11.5-kDa Zn(2+)-binding protein (ZnBP) was covalently linked to Sepharose. Affinity chromatography with a cytosolic subfraction from liver resulted in purification of a predominant 38-kDa protein. In comparable experiments with brain cytosol a 39-kDa protein was enriched. The ZnBP-protein interactions were zinc-specific. Both proteins were identified as fructose-1,6-bisphosphate aldolase. Experiments with crude cytosol showed zinc-specific interaction of additional enzymes involved in carbohydrate metabolism. From liver cytosol greater than 90% of the following enzymes were specifically retained: aldolase, phosphofructokinase-1, hexokinase/glucokinase, glucose-6-phosphate dehydrogenase, glycerol-3-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-1,6-bisphosphatase. Glucose-6-phosphate isomerase, phosphoglycerate kinase, enolase, lactate dehydrogenase, and most of triosephosphate isomerase remained unbound. From L-type pyruvate kinase only the phosphorylated form seems to interact with ZnBP. Using brain cytosol hexokinase, phosphofructokinase-1, and aldolase were completely bound to the affinity column, whereas glucose-6-phosphate isomerase, phosphoglycerate kinase, enolase, lactate dehydrogenase, pyruvate kinase, and most of triose-phosphate isomerase remained unbound. The behavior of glucose-6-phosphate dehydrogenase and glycerol-3-phosphate dehydrogenase from this tissue could not be followed. A possible function of ZnBP in supramolecular organization of carbohydrate metabolism is proposed.
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PMID:Key enzymes of carbohydrate metabolism as targets of the 11.5-kDa Zn(2+)-binding protein (parathymosin). 183 54

We have developed a method for the simultaneous purification of hexokinase, glucosephosphate isomerase, phosphofructokinase, fructose-1,6-bisphosphate aldolase, triosephosphate isomerase, D-glyceraldehyde-phosphate dehydrogenase, phosphoglycerate kinase, glycerol-3-phosphate dehydrogenase and glycerol kinase from Trypanosoma brucei in yields varying over 8-55%. Crude glycosomes were prepared by differential centrifugation of cell homogenates. Subsequent hydrophobic interaction chromatography on phenyl-Sepharose resulted in six pools containing various mixtures of enzymes. These pools were processed via affinity chromatography (immobilized ATP), hydrophobic interaction chromatography (octyl-Sepharose) and ion-exchange chromatography (CM- and DEAE-cellulose) which resulted in the purification of all nine enzymes. The native enzyme and subunit molecular masses, as determined by gel filtration and gel electrophoresis under denaturing conditions, were compared with those of their homologous counterparts from other organisms. Trypanosomal hexokinase is a hexamer and differs in subunit composition from the mammalian enzymes (monomers) as well as in subunit size (51 kDa versus 96-100 kDa, respectively). Phosphofructokinase only differs in subunit size (51 kDa for T. brucei versus 80-90 kDa for mammals) but had identical subunit composition (tetrameric). The others all have the same subunit composition as their mammalian counterparts. Except for triosephosphate isomerase, all Trypanosoma enzymes have subunits which are 1-5 kDa larger in size. Together these nine enzymes contribute 3.3 +/- 1.6% to the total cellular protein of T. brucei and at least 90% to the total glycosomal protein. A comparison of calculated intraglycosomal concentrations of the enzymes with the glycosomal metabolite concentrations shows that in the case of aldolase, glyceraldehyde-phosphate dehydrogenase and phosphoglycerate kinase, the concentration of active sites is of the same order of magnitude as that of their reactants. A common feature of the glycosomal glycolytic enzymes (with the exception of glucosephosphate isomerase) is that they are highly basic proteins with pI values between 8.8 and 10.2, values which are 1-4 higher than in the case of their mammalian cytosolic counterparts and 3-6 higher than in the case of the various unicellular organisms. It is suggested that both the larger subunit size and the basic character of the T. brucei glycolytic proteins are involved in the routing of the enzymes from their site of biogenesis (the cytosol) towards their site of action (the glycosome).
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PMID:Glycolytic enzymes of Trypanosoma brucei. Simultaneous purification, intraglycosomal concentrations and physical properties. 294 90

A method for determining Control Coefficients is proposed for systems studied in vitro and applied to a model pathway. Rat liver extract, which converts glucose into glycerol 3-phosphate, was used with the addition to the incubation mixture of fructose-bisphosphate aldolase, triose-phosphate isomerase and glycerol-3-phosphate dehydrogenase as 'auxiliary' enzymes, which leaves all the control on the first three enzymes. The flux of the metabolic pathway was recorded by assaying NADH decay. Flux Control Coefficients (CJE) of hexokinase, glucose-6-phosphate isomerase and phosphofructokinase were calculated by titration of the system with increasing quantities of extraneous enzymes. It is shown that the summation property is fulfilled. The applicability of this procedure to study the control in any metabolic pathway is discussed. Possible relevance of the method to conditions in vivo and its limitations are considered.
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PMID:Kinetics of metabolic pathways. A system in vitro to study the control of flux. 370 39

The activities of glycolytic enzymes were determined in human autoptic temporal lobes from patients with different forms of dementia. For some enzymes (hexokinase, phosphofructokinase and phosphoglycerate mutase) the effect seen in dementia can be regarded as an intensification of the normal ageing affect. For other enzymes (aldolase, phosphoglucose isomerase, triosephosphate isomerase and lactate dehydrogenase) no changes in enzyme activities corresponding to those found in dementia are observed in the normal ageing process. These effects are most pronounced in the non-vascular Alzheimer cases. With the exception of triosephosphate isomerase and lactate dehydrogenase, enzyme activity is also reduced in bronchopneumonia. The effects of dementia and bronchopneumonia on the activities of glycolytic enzymes in human autoptic brain tissue are often difficult to distinguish.
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PMID:Glycolytic enzymes from human autoptic brain cortex: normal aged and demented cases. 625 57

Evidence is presented for the occurrence of glycosomes (organelles resembling peroxisomes) in four major species of Leishmania (viz. L. major, L.m. mexicana, L. b. braziliensis and L. donovani), based on latency as well as differential and isopycnic centrifugation studies. The enzymes involved in glycolysis; (hexokinase, phosphoglucose isomerase, phosphofructokinase, fructose-1,6-bisphosphate aldolase, triosephosphate isomerase, glyceraldehyde-phosphate dehydrogenase and phosphoglycerate kinase); glycerol metabolism (sn-glycerol-3-phosphate dehydrogenase and glycerol kinase); carbon dioxide fixation (phosphoenolpyruvate carboxykinase and possibly malate dehydrogenase); together with an enzyme involved in the beta-oxidation of fatty acids (3-beta-hydroxybutyryl coenzyme A dehydrogenase); a key enzyme in the synthesis of ether lipids (dihydroxyacetone phosphate acyltransferase) as well as the ADP utilising enzyme adenylate kinase, were all found associated, at least in part, with a subcellular organelle which had a buoyant density in sucrose gradients of 1.21 to 1.24 g cm-3. Little variance in enzyme composition was found between the different species of Leishmania or in comparison with other members of the Trypanosomatidae, supporting the unifying principle that glycosomes are a unique characteristic of this family. The occurrence of important catabolic, anabolic and anaplerotic pathways in the glycosomes of Leishmania renders them prime targets for chemotherapy.
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PMID:The occurrence of glycosomes (microbodies) in the promastigote stage of four major Leishmania species. 644 18

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

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 structure of the isocitrate dehydrogenase (IDH) complex with bound alpha-ketoglutarate, Ca2+, and NADPH was solved at 2.7-A resolution. The alpha-ketoglutarate binds in the active site at the same position and orientation as isocitrate, with a difference between the two bound molecules of about 0.8 A. The Ca2+ metal is coordinated by alpha-ketoglutarate, three conserved aspartate residues, and a pair of water molecules. The largest motion in the active site relative to the isocitrate enzyme complex is observed for tyrosine 160, which originally forms a hydrogen bond to the labile carboxyl group of isocitrate and moves to form a new hydrogen bond to Asp 307 in the complex with alpha-ketoglutarate. This triggers a number of significant movements among several short loops and adjoining secondary structural elements in the enzyme, most of which participate in dimer stabilization and formation of the active-site cleft. These rearrangements are similar to the ligand-binding-induced movements observed in globins and insulin and serve as a model for an enzymatic mechanism which involves local shifts of secondary structural elements during turnover, rather than large-scale domain closures or loop transitions induced by substrate binding such as those observed in hexokinase or triosephosphate isomerase.
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PMID:Structure of isocitrate dehydrogenase with alpha-ketoglutarate at 2.7-A resolution: conformational changes induced by decarboxylation of isocitrate. 836 1


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