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:4.1.2.13 (aldolase)
3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Highly purified glycosomes were isolated from Trypanosoma brucei bloodstream forms and cultured procyclic trypomastigotes. A comparison of the specific activities of glycosomal enzymes revealed that glycosomes from insect stages had decreased levels of hexokinase, phosphoglucose isomerase, phospho-fructokinase, fructose-bisphosphate aldolase, glyceraldehyde-phosphate dehydrogenase and phosphoglycerate kinase, but contained increased levels of adenylate kinase, malate dehydrogenase and phosphoenolpyruvate carboxykinase. Glycosomes from bloodstream forms were almost totally devoid of the latter two activities. Comparison of the two types of glycosomes by sodium dodecylsulphate-polyacrylamide gel electrophoresis revealed that bloodstream form glycosomes contained 3 prominent polypeptides (64, 46 and 40 kDa) which were hardly detectable in insect stage glycosomes, whereas the latter contained 3 insect stage specific bands with molecular weight of 34 000, 61 000 and 77 000 and 4 additional bands with molecular weights between 94 000 and 110 000. Both types of glycosome contained the phospholipids phosphatidylcholine and phosphatidylethanolamine. Insect stage glycosomes contained in addition also phosphatidylinositol and some phosphatidylserine.
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PMID:A comparison of the glycosomes (microbodies) isolated from Trypanosoma brucei bloodstream form and cultured procyclic trypomastigotes. 674 87

Band 3, the anion transport protein of the human erythrocyte, provides the site of association of certain glycolytic enzymes with the membrane. We have now demonstrated that glyceraldehyde-3-P dehydrogenase is inhibited, reversibly and completely, when membrane bound. The inhibition was competitive with respect to NAD+ and arsenate, but was noncompetitive with glyceraldehyde-3-P. Peptide fragments containing the NH2-terminal 23 residues of band 3 also inhibited the enzyme and displaced it from ghosts. Thus, the red cell membrane binding site for glyceraldehyde-3-P dehydrogenase is the same as that for aldolase, the polyanionic NH2-terminal region of the band 3 polypeptide.
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PMID:Effect of red cell membrane binding on the catalytic activity of glyceraldehyde-3-phosphate dehydrogenase. 705 25

Purified glycolytic enzymes were individually chromatographed through columns of Sepharose 4B containing a covalently bound F-actin-tropomyosin complex. Five of these enzymes, aldolase, glyceraldehyde-phosphate dehydrogenase, lactate dehydrogenase, pyruvate kinase, and phosphoglycerate kinase were able to interact with the complex. Glucosephosphate isomerase, triosephosphate isomerase, phosphoglycerate phosphomutase, and enolase did not bind to the F-actin-tropomyosin matrix. One nonbinding enzyme, phosphoglycerate phosphomutase, was observed to interact with F-actin-tropomyosin if the column was preloaded with lactate dehydrogenase. Since at least four other glycolytic enzymes did not associate with actin directly, it is suggested that if a glycolytic enzyme complex exists, these nonadsorbing enzymes must interact with one or more of the enzymes which do bind to actin.
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PMID:Interaction of muscle glycolytic enzymes with thin filament proteins. 729 40

The presence of hexokinase, aldolase, glyceraldehyde-phosphate dehydrogenase, phosphoglycerate kinase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase has been detected in Y. enterocolitica, which indicates the glycolytic and pentosophosphate pathways of glucose catabolism. Y. enterocolitica can be classified as an opportunistic anaerobic microorganism on the basis of the whole complex of its characteristics (growth in both aerobic and anaerobic conditions, the reduction of nitrates into nitrites, the presence of higly active glycolytic enzymes).
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PMID:[Glucose metabolism in Yersinia enterocolitica cells]. 743 20

Glycolysis in the trypanosome represents an important target for the development of new therapeutic agents due to the fact that this metabolism is essential for the parasite, glucose being its sole source of energy. In addition, different features of this metabolism and those associated with glycolytic enzymes offer opportunities for the development of efficient and selective compounds. Examples are given in this work of inhibitors directed to the enzymes aldolase and glyceraldehyde-phosphate-dehydrogenase and also of molecules acting specifically on the clusters of basic amino-acids present at the surfaces of the glycolytic enzymes in the parasite.
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PMID:Inhibition of the glycolytic enzymes in the trypanosome: an approach in the development of new leads in the therapy of parasitic diseases. 802 65

We present a comparative study of Escherichia coli with normal and increased amounts of fructose-1,6-bisphosphate aldolase. Most experiments employed a resting cell system involving a high cell density (so as to obtain the soluble pool by direct extraction) and anaerobic incubation in the presence of chloramphenicol. Glucose use is linear with time with a rate ca. half of that in growth, fermentation is almost quantitative, and metabolite concentrations reach a quasi steady state. Increased amount of aldolase had little effect on glucose flux; fructose-1,6-P2 concentration decreased by ca. one-third, and the extent of equilibration of its two halves, measured by a dismutation procedure on samples taken during metabolism of [6-14C]glucose, increased from 0.33 [(cpm in C1-3)/(cpm in C1-6)] to 0.43. Using the simplest model, that increased amount of aldolase does not perturb net flux or later metabolites, together with the steady-state rate equations for aldolase and triose-P isomerase, we show that the results with resting cells fit with the extra enzyme being fully active, and do not necessitate special assumptions concerning a glycolytic complex, metabolite compartmentation, or secondary mechanisms assuring high metabolite concentration. However, the fit does require that the measured Vmax values substantially underestimate the actual ones. Calculation also shows that the forms of the predicted curves--and hence the fit with experimental data--of fructose-1,6-P2 concentration and labeling as a function of the amount of aldolase are highly dependent on glyceraldehyde-3-P concentration but independent of the kinetic parameters of aldolase.
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PMID:Glucose metabolism in Escherichia coli and the effect of increased amount of aldolase. 848 46

Enzyme inactivation was utilized to study subunit interaction in the homotetrameric glycolytic enzyme, aldolase. Isoenzymes from rabbit liver and skeletal muscle were inactivated in the presence of Pi and d-glyceraldehyde-P to a maximum stoichiometry of one modification per aldolase subunit. Subunit modification increased net negative charge on each subunit surface and was used to resolve modified aldolase isoenzymes into various chromatographic species. A combination of anion-(Mono Q) and cation- (Mono S) exchange chromatography separated the modified aldolase homotetramers into three distinct enzyme populations: unchanged enzyme, fully modified enzyme corresponding to one ligand molecule incorporated per subunit and partially modified enzyme in which only one subunit out of four is modified. Both fully and partially modified species were devoid of catalytic activity. Activity loss through modification of a single subunit in both aldolase isoenzymes indicates tightly coupled communication between subunit active sites and suggests simple functional regulation of aldolases.
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PMID:Subunit interaction in mammalian aldolases. 916 99

The compartmentation of key processes in sugar, organic acid and amino acid metabolism was studied during the development of the flesh and seeds of grape (Vitis vinifera L.) berries. Antibodies specific for enzymes involved in sugar (cell wall and vacuolar invertases, pyrophosphate: fructose 6-phosphate phosphotransferase, aldolase, NADP-glyceraldehyde-P dehydrogenase, cytosolic fructose 1,6-bisphosphatase), photosynthesis (Rubisco, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase), amino acid metabolism (cytosolic and mitochondrial aspartate aminotransferases, alanine aminotransferase, glutamate dehydrogenase, glutamine synthetase), organic acid metabolism (phosphoenolpyruvate carboxylase, NAD- and NADP-dependent malic enzyme, ascorbate peroxidase), and lipid metabolism (acetyl CoA carboxylase, isocitrate lyase) were used to determine how their abundance changed during development. There were marked changes in the abundance of many of these enzymes in both the flesh and seeds. The intercellular location of some enzymes was investigated using immunohistochemistry. Several enzymes (e.g. phosphoenolpyruvate carboxylase and those involved in amino acid metabolism) were associated with tissues likely to function in the transport of imported assimilates, such as the vasculature. Although other enzymes (e.g. NADP-malic enzyme and soluble acid invertase, involved in the metabolism of sugars and organic acids) were largely present in the parenchyma cells of the flesh, their distribution was extremely heterogeneous. This study shows that when considering the metabolism of complex structures such as fruit, it is essential to consider how metabolism is compartmentalized between and within different tissues, even when they are apparently structurally homogeneous.
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PMID:An immunohistochemical study of the compartmentation of metabolism during the development of grape (Vitis vinifera L.) berries. 1093 59

The hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324, rather than the type strain VC16, was found to grow on starch and sulfate as energy and carbon source. Fermentation products and enzyme activities were determined in starch-grown cells and compared to those of cells grown on lactate and sulfate. During exponential growth on starch, 1 mol of glucose-equivalent was incompletely oxidized with sulfate to approximately 2 mol acetate, 2 mol CO2 and 1 mol H2S. Starch-grown cells did not contain measurable amounts of the deazaflavin factor F420 (<0.03 nmol/mg protein) and thus did not show the F420-specific green-blue fluorescence. In contrast, lactate (1 mol) was completely oxidized with sulfate to 3 mol CO2 by strain 7324, and lactate-grown cells contained high amounts of F420 (0.6 nmol/mg protein). In extracts of starch-grown cells, the following enzymes of a modified Embden-Meyerhof pathway were detected: ADP-dependent hexokinase (ADP-HK), phosphoglucose isomerase, ADP-dependent 6-phosphofructokinase (ADP-PFK), fructose-1,6-phosphate aldolase, glyceraldehyde-3-phosphate:ferredoxin oxidoreductase (GAP:FdOR), phosphoglycerate mutase, enolase, and pyruvate kinase (PK). Specific activities of ADP-HK, ADP-PFK, GAP:FdOR, and PK were significantly higher in starch-grown cells than in lactate-grown cells, indicating induction of these enzymes during starch catabolism. Pyruvate conversion to acetate involved pyruvate:ferredoxin oxidoreductase and ADP-forming acetyl-CoA synthetase. The findings indicate that the archaeal sulfate reducer A. fulgidus strain 7324 converts starch to acetate via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming). This is the first report of growth of a sulfate reducer on starch, i.e. on a polymeric sugar.
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PMID:Sugar utilization in the hyperthermophilic, sulfate-reducing archaeon Archaeoglobus fulgidus strain 7324: starch degradation to acetate and CO2 via a modified Embden-Meyerhof pathway and acetyl-CoA synthetase (ADP-forming). 1170 74


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