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)

In Arthrobacter pyridinolis, a respiration-coupled transport system for L-rhamnose caused accumulation of free L-rhamnose, while a phosphoenolpyruvate: L-rhamnose phosphotransferase system caused accumulation of L-rhamnose I-phosphate (Levinson & Krulwich, 1974). The pathways for subsequent metabolism of L-rhamnose and L-rhamose I-phosphate have now been investigated. Arthrobacter pyridinolis contains an inducible L-rhamnose isomerase and L-rhamnulokinase, as well as a constitutive L-rhamnulose I-phosphate aldolase. Results with mutants which are unable to metabolize L-rhamnose suggest the presence of an L-rhamnose I-phosphate phosphatase, which forms free L-rhamnose by hydrolysis of L-rhamnose I-phosphate produced by the phosphotransferase system. Mutants which lack this enzyme exhibited severe inhibition of growth in the presence of L-rhamnose plus any of a variety of carbon sources. There is some evidence that this inhibition was due to accumulation of L-rhamnose I-phosphate at toxic concentrations within the bacteria. The metabolism of L-rhamnose transported by the phosphotransferase system therefore appears to occur by hydrolysis of L-rhamnose I-phosphate to free L-rhamnose by a phosphatase. Metabolism of the L-rhamnose thus produced, and of that accumulated by the respiration-coupled transport system, the proceeds by the sequence of reactions: L-rhamnose leads to L-rhamnulose leads to L=rhamnulose I-phosphate leads to dihydroxyacetone phosphate plus L-lactaldehyde.
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PMID:Metabolism of L-rhamnose in Arthrobacter pyridinolis. 18 6

The activity of hexokinase, glycose-6-phosphatase, phosphofructokinase, fructose diphosphate aldolase and ketose-1-phosphate aldolase was studied in kidneys, blood serum and urine or rats, the proximal and distal areas of their nephron being affected with the chemical substances. A pronounced decrease in the activity of the mentioned enzymes in the renal tissue was greater with afection of the nephron proximal area. The activity of the mentioned enzymes in urine, vice versa, increases sharply and in blood serum it was almost unchanges (exception for keto-1-phosphate aldolase). The pronounced enzyme uria may reflect the deep changes in epithelium cells of canals, especially of proximal ones where the enzymes under study are mainly localized.
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PMID:[Activity of glycolysis enzymes in kidneys, blood serum and urine with toxicity of certain segments of the nephron]. 20 89

The possibility of interaction between purified rabbit muscle aldolase and D-glyceraldehyde-3-phosphate dehydrogenase was studied by rapid kinetic methods, by analyzing the kinetics of the consecutive reaction catalyzed by the coupled enzyme system. The Km of the intermediary product, glyceraldehyde 3-phosphate, produced by aldolase was determined in the coupled reaction for glyceraldehyde-3-phosphate dehydrogenase. Its value corresponds to that of the aldehyde (active) form of glyceraldehyde 3-phosphate, although in the given conditions the aldehyde leads to diol interconversion is faster than the enzymic reaction catalyzed by glyceraldehyde-3-phosphate dehydrogenase. We suggest that above a certain concentration of the enzymes the glyceraldehyde 3-phosphate produced by aldolase gets direct access to glyceraldehyde-3-phosphate dehydrogenase without participating in the aldehyde leads to diol interconversion which otherwise would occur if the substrate were to mix with the bulk medium.
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PMID:Kinetic evidence for interaction between aldolase and D-glyceraldehyde-3-phosphate dehydrogenase. 20 15

Caulobacter crescentus wild-type strain CB13 is unable to utilize galactose as the sole carbon source unless derivatives of cyclic AMP are present. Spontaneous mutants have been isolated which are able to grow on galactose in the absence of exogenous cyclic nucleotides. These mutants and the wild-type strain were used to determine the pathway of galactose catabolism in this organism. It is shown here that C. crescentus catabolizes galactose by the Entner-Duodoroff pathway. Galactose is initially converted to galactonate by galactose dehydrogenase and then 2-keto-3-deoxy-6-phosphogalactonate aldolase catalyzes the hydrolysis of 2-keto-3-deoxy-6-phosphogalactonic acid to yield triose phosphate and pyruvate. Two enzymes of galactose catabolism, galactose dehydrogenase and 2-keto-3-deoxy-6-phosphogalactonate aldolase, were shown to be inducible and independently regulated. Furthermore, galactose uptake was observed to be regulated independently of the galactose catabolic enzymes.
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PMID:Galactose catabolism in Caulobacter crescentus. 21 Jan 53

Initial rate kinetic studies with bovine liver fructose-1,6-bisphosphatase were carried out in both directions of the reaction to determine the sequence of product release from the enzyme. Product inhibition by fructose-6-P was found to be S-linear, I-linear noncompetitive relative to fructose-1,6-bisphosphate, whereas inorganic orthophosphate was determined to be linear competitive with respect to the substrate. The kinetics of the reverse reaction were studied by coupling the phosphatase reaction to the aldolase, triosephosphate isomerase, and glycerolphosphate dehydrogenase reactions. The kinetic results were found to be in harmony with the Uni Bi ordered and random sequential mechanisms as well as a Uni Bi ping-pong mechanism. The nomenclature is that of Cleland (Cleland, W.W. (1963) Biochim. Biophys. Acta 67, 104-137). However, nonkinetic considerations, when taken together with the kinetic results, suggest that the steady state ordered Uni Bi mechanism is the most likely possibility. There is evidence that isomerization of the binary complex of enzyme and phosphate occurs in the kinetic mechanism. Although magnesium is required for the reverse reaction, there is no evidence to suggest that the enzyme discriminates between the magnesium-associated or divalent cation-free forms of the substrates.
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PMID:Kinetic studies of bovine liver fructose-1,6-bisphosphatase. 22 Feb 58

The activity of key glycolysis enzymes (hexokinase, glucose-6-phosphatase, phosphofructokinase, fructose-diphosphatase and ketose-1-phosphate aldolase) in the kidney tissue and its subcellular structures was studied in normal rats and in rats with experimental acute renal insufficiency. It is established that considerable biochemical changes in the kidney tissues affecting all the elements of cellular structures occur under acute lesion of the kidneys. The activity of the enzymes under study under acute renal insufficiency lowers to a greater extent in those subcellular structures of the kidneys where they are mainly localized. The arising disturbances in permeability of the kidneys cellular membranes intensify the release of the mentioned enzymes to blood serum and urine, that in its turn disturbs the coordination of certain glycolysis stages.
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PMID:[Activity of glycolysis key enzymes in subcellular structures of normal kidneys and under acute renal insufficiency]. 22 62

This paper starts a series on red blood cell (RBC) metabolism in patients with chronic renal failure (CRF). The glycolytic enzyme levels and in vitro half-lives of these patients' RBCs were determined. A number of enzymes (hexokinase, glucose-6-phosphate isomerase, fructose-6-phosphate kinase, aldolase, glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase) showed higher activities than in normal control RBCs. Other enzyme activities were normal. These results were discussed and several possible mechanisms considered. We favour the point of view of a shortened life span of the RBCs in CRF, making the most unstable enzymes of the glycolytic sequence appear increase as compared with normal controls.
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PMID:Metabolism of red blood cells in chronic renal failure. I. Glycolytic enzyme levels. 22 98

A procedure for the coupling at pH 7.2 of p-carboxy benzene diazonium chloride with rabbit muscle aldolase supported on phosphocellulose is described and some of the spectroscopic, structural and catalytic features of the material obtained are reported. The tetrameric azoenzyme is homogeneous in disc gel electrophoresis even in the presence of 8 M urea. Twelve molecules of the reactant are bound to the protein. Eight azocysteins are identified by both spectroscopic studies and amino acid analysis. The presence of one azohistidine is suggested by the spectroscopic data along with the presence of other, as yet unknown, chromophores. The azoaldolase shows unchanged catalytic properties using both D-fructose 1,6-bisphosphate and D-fructose 1-phosphate as substrates, as compared with the native enzyme. The pH profile of the enzyme activity is broadened towards the alkaline region but no changes occur in the physiological range of pH.
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PMID:Catalytically active azoaldolase. Preparation on solid support. 23 36

Extracts of Pseudomonas citronellolis cells grown on glucose or gluconate possessed all the enzymes of the Entner-Doudoroff pathway. Gluconokinase and either or both 6-phosphogluconate dehydratase and KDPG aldolase were induced by growth on these substrates. Glucose and gluconate dehydrogenases and 6-phosphofructokinase were not detected. Thus catabolism of glucose proceeds via an inducible Entner-Doudoroff pathway. Metabolism of glyceraldehyde 3-phosphate apparently proceeded via glyceraldehyde 3-phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, enolase and pyruvate kinase. These same enzymes plus triose phosphate isomerase were present in lactate-grown cells indicating that synthesis of triose phosphates from gluconeogenic substrates also occurs via this pathway. Extracts of lactate grown-cells possessed fructose diphosphatase and phosphohexoisomerase but apparently lacked fructose diphosphate aldolase thus indicating either the presence of an aldolase with unusual properties or requirements or an alternative pathway for the conversion of triose phosphate to fructose disphosphate. Cells contained two species of glyceraldehyde 3-phosphate dehydrogenase, one an NAD-dependent enzyme which predominated when the organism was grown on glycolytic substrates and the other, an NADP-dependent enzyme which predominated when the organism was grown on gluconeogenic substrates.
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PMID:Enzymatic analysis of the pathways of glucose catabolism and gluconeogenesis in Pseudomonas citronellolis. 23 56

Paracatalytic enzyme modifications result from the oxidation of enzyme-substrate carbanions by extrinsic oxidants. During the oxidation of enzyme-activated substrates, transiently reactive intermediates are generated which, without being released from the enzyme, modify groups at the active site. For enzymes producing carbanion intermediates, the combination of the normal substrate with a suitable electron acceptor has thus been proposed as a highly specific binary system for their active site-directed modification. In this study, the structural features of paracatalytically modified fructose-1,6-bisphosphate aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phosphate lyase, EC 4.1.2.13) from rabbit muscle have been elucidated. This enzyme is completely inactivated within 60 min in the presence of fructose 1,6-bisphosphate in saturating concentration and 0.5 mM hexacyanoferrate(III) (pH 7.6, 25 degrees C). The inactivation is caused by covalent incorporation of one triosephosphate derivative per subunit. Peptide analysis showed that the triosephosphate derivative forms an intrachain crosslink between lysine-146 and lysine-227. According to previous independent experimental evidence, both lysyl residues are located at the active site: the epsilon-amino group of lysine-227 forms a Schiff base intermediate with the carbonyl group of the substrate [Lai, C. Y., Nakai, N. & Chang, D. (1974) Science 183, 1204-1206] and alkylation of lysine-146 by the affinity labeling reagent N-bromoacetylethanolamine phosphate inactivates the enzyme [Hartman, F. C. & Brown, J. P. (1976) J. Biol. Chem. 251, 3057-3062]. The present data thus establish paracatalytic modification as a mode of active site-directed enzyme modification.
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PMID:Paracatalytic modification of aldolase: a side reaction of the catalytic cycle resulting in irreversible blocking of two active-site lysyl residues. 28 42


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