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)

The rate of oxidation of ferricyanide of the aldolase-dihydroxyacetone phosphate complex was measured under different conditions. The following conclusions are drawn. 1. In the cleavage of fructose diphosphate, catalysed by native aldolase, the steady-state concentration of the enzyme-dihydroxyacetone phosphate carbanion intermediate represents less than 6% of the total enzyme-substrate intermediates. 2. Fructose diphosphate and dihydroxyacetone phosphate compete for the four catalytic sites on aldolase, the binding of fructose diphosphate being about twice as tight. 3. The equilibrium concentration of the carbanion intermediate formed by reaction of carboxypeptidase-treated aldolase with dihydroxyacetone phosphate is independent of pH between 5.0 and 9.0. The rates of fromation of the carbanion intermediate and of the reverse reaction are, however, concomitantly increased by increasing pH between 5.0 and 6.5.
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PMID:Fructose 1,6-diphosphate aldolase from rabbit muscle. Effect of pH on the rate of formation and on the equilibrium concentration of the carbanion intermediate. 0 60

Fructose diphosphate aldolase (D-fructose-1,6-biphosphate D-glyceraldehyde-3-phosphate lyase, EC 4.1.2.13) from rabbit heart has been purified and obtained in crystalline form. The preparations are homogeneous on the basis of disc gel electrophoresis and ultracentrifugation. The catalytic and the molecular properties indicate that this is aldolase A. A comparison was made between rabbit heart aldolase and the rabbit muscle enzyme. The sedimentation coefficient, energy of activation and Michaelis constant for Fru-1,6-P2 were found to be identical with the values obtained for the muscle enzyme. As in case of the muscle enzyme, heart aldolase was found to have a broad pH optimum, remarkable stability over a wide pH range, and the ability to form a Schiff base intermediate with dihydroxyacetone phosphate upon reduction with borohydride. Cleavage of the methionyl bonds with CNBr yields the same pattern as obtained with the muscle enzyme.
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PMID:Purification and properties of rabbit heart muscle aldolase. 1 26

Fructose-1,6-bisphosphate aldolase (D-fructose-1,6-bisphosphate D-glyceraldehyde-3-phyosphate-lyase, EC 4.1.2.13) was isolated from buffalo muscle by fractionation with ammonium sulphate and subsequent purification by phosphocellulose column chromatography using a linear salt gradient. As judged by gel filtration and electrophoresis in polyacrylamide gel, the enzyme was homogeneous with respect to size and charge. The molecular weight and Stokes radius of the enzyme were determined from its elution profile on a calibrated Sephadex column and the respective values were 162000 and 4.55 nm. The diffusion coefficient and frictional ratio were computed to be 4.8-10(7) cm2-s-1 and 1.27, respectively. The molecular weight of the polypeptide chain as measured by aodium dodecyl sulphate polyacrylamide gel electrophoresis was 40750. This taken together with the native molecular weight suggested a four-subunit model for the protein. The N- AND C-terminal residues of polypeptide chains were identified to be proline and tyrosine, respectively. At pH 8.0 the Michaelis-Menten constant and maximum attainable velocity were found to be 8.1 muM and 27 muM Fru-1,6-P2 split/min per mg, respectively. The buffalo muscle aldolase was found to be similar to rabbit muscle aldolase in physico-chemical properties. However, the two enzymes differ significantly in pH optimum; the p optima of the buffalo and rabbit enzymes were determined under identical conditions to be 8.0 and 8.6, respectively.
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PMID:Isolation of buffalo muscle aldolase and comparison of its properties with those of rabbit muscle aldolase . 1 72

Fructose-1,6-bisphosphate aldolase (Fru-P2A) from a psychrophilic marine bacterium was found to be Class II aldolase based on activation by K+, activation by divalent cations, inactivation by EDTA, low molecular weight, and similar values for Km, Vmax, and Arrhenius activation energy. This enzyme was not markedly different in amino acid composition from the enzymes from mesophilic and thermophilic organisms, yet it has unusual thermal properties.
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PMID:Fructose-1,6-bisphosphate aldolase from Vibrio marinus, a psychrophilic marine bacterium. 3 85

Fructose 6-sulfate was synthesized by direct sulfurylation of fructose and was isolated by two selective steps: (a) conversion of the 6-sulfuryl ester to fructose 1-phosphate-6-sulfate with phosphofructokinase; (b) conversion of fructose 1-phosphate-6-sulfate to fructose 6-sulfate by fructose-1,6-diphosphatase. Utilizing crystalline sheep heart phosphofructokinase, kinetic studies with the alternative substrate were carried out at pH 8.2 which is optimal for nonallosteric kinetics. The data are consistent with an ordered addition of the two substrates with the first, MgATP, being at thermodynamic equilibrium. The Vmax and Km obtained with fructose 6-sulfate were 0.03- and 100-fold, respectively, that obtained with the natural substrate. The study suggests that the divalent phosphoryl moiety is intimately involved in the active site conformation. Identification of the product of the reaction, fructose 1-phosphate-6-sulfate, was confirmed through studies with aldolase, fructose-1,6-diphosphatase, and by 31P NMR. The utilization of fructose 6-sulfate as a substrate by yeast glucose-6-phosphate isomerase could not be demonstrated.
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PMID:Studies on heart phosphofructokinase. Use of fructose 6-sulfate as an alternative substrate to study the mechanism of action and active site specificity. 13 39

Fructose-diphosphate aldolase [ED 4.1.2.13] was isolated from horseshoe crab ( living fossil) muscle and some molecular and enzymatic properties were examined. The enzyme was a tetramer with a molecular weight of about 160,000. The enzyme activity was inhibited by reduction with borohydride in the presence of the substrate and was inactivated by carboxypeptidase A [EC 3.4.12.2] digestion. The pH optima for fructose-diphosphate (FDP) and fructose-1-phosphate (F1P) activities were 6.5--8 and 7.5--8.2, respectively. The ratio of FDP/F1P activities was 30 and Km values were 1.7 times 10- minus 5 M and 2.5 times 10- minus 3 M, respectively, for the two substrates. The horseshoe crab aldolase was classified as class 1, type A, based on the results obtained. Extensive homology in various properties of the enzyme was observed when it was compared with enzymes from other sources, though some differences could be found in the amino acid composition and in the kinetic properties.
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PMID:Fructose-diphosphate aldolase of Horseshoe crab (Tachypleus tridentatus). 23 86

Fructose-1,6-P2 was immobilized by sodium borohydride reduction of the Schiff base formed with aminated agarose (AH-Sepharose 4B). The coupling occurs with high yield (25 mumoles immobilized fructose-1,6-P2 per ml packed gel) at neutral pH and room temperature. Schiff base reduction thus provides a convenient and mild coupling prodecure for sugar phosphates preserving their labile phospho ester bonds. As exemplified by a new isolation procedure for fructose-1,6-P2 aldolase from yeast, sugar phosphates insolubilized in this manner may be used for affinity chromatography of the corresponding enzymes, provided that contaminating unspecific phosphatases are removed in a preceding fractionation step.
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PMID:Coupling of fructose-1,6-P2 to aminated agarose by Schiff base reduction. Affinity chromatography of yeast aldolase. 33 Jan 92

Changes in enzymes and metabolites of the carbohydrate metabolism in skeletal muscles were studied in mice after intracerebral inoculation of dengue type 2 virus. It was noted that lactic dehydrogenase, aldolase, phosphoglucoisomerase, phosphoglucomutase, GO-T and GP-T activity were enhanced initially by two- to three-fold, reaching a peak on day 5. As the illness appeared in mice, all the enzyme activities were lowered and were about three times less in the paralytic stage on the 8th day as compared to controls. Fructose-1,6-diphosphatase activity was increased on the 4th and 5th days but decreased later. Acid phosphatase increased abruptly from the 6th day while alkaline phosphatase activity was irregular. Creatine increased on the 4th and 5th days but diminished later. Glycogen decreased from the beginning and was lowest on the 5th day, but the levels increased later and were maximum in paralysed muscles. On the other hand, lactic acid began accumulating in the muscles and was maximum on the 5th day, then declined. Dengue virus was detected in the muscles from the 2nd day but higher titres were seen from the 6th day. Changes similar to the preparalytic stage of mice may occur in human beings, causing myalgia.
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PMID:Biochemical study of certain enzymes and metabolites of the carbohydrate metabolism in the skeletal muscle of the dengue virus-infected mice. 69 Jun 8

Fructose-1,6-diphosphate aldolase has been purified to homogeneity 62.0 and 58.3 fold from young and old nematodes respectively. The aldolase preparations from young (7 days) and old (35 days) animals are indistinguishable in their electrophoretic mobility, molecular weight of the tetramer (158,000) and monomer (40,000), and Km, although the "old" enzyme is more heat stable than the "young" enzyme. Enzyme from old animals has only about 55% specific activity per mg purified protein of the "young" enzyme and its catalytic activity per unit of enzyme antigen is about 50% of that of the enzyme from young animals. Immunological identity of purified enzyme from old and young animals was established by the Ouchterlony technique by antiserum produced against purified "young" enzyme and antiserum against purified "old" enzyme. Thus, this work shows for the first time that the altered form of an enzyme which appears in senescent animals apparently does not possess extra antigenic sites which are acquired as a function of age.
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PMID:Age related alterations in purified fructose-1,6-diphosphate aldolase from the nematode Turbatrix aceti. 89 8

In the subcommissural organ (SCO) of the guinea pig, rat, golden hamster, and mouse the activity and distribution of enzymes related to the energy-supplying metabolism and of some marker enzymes of different cell organelles have been investigated by means of mostly modified histochemical methods. The results were compared with findings in the ciliated ependyma of the ventricular wall and with those in the ependyma of the choroid plexus of the third ventricle. In the ependymal part of the SCO only a moderate activity of hexokinase is observed in its specialized columnar cells whereas a high activity is present both in the ciliated ependyma and the choroid plexus. - The staining pattern of glucose-6-phosphatase is similar to that of hexokinase but this enzyme is found is the SCO only. - Likewise hexokinase, glycogen granules and enzymes related to glycogen metabolism (phosphoglucomutase, uridine-diphosphoglucose pyrophosphorylase, glycogen synthetase and phosphorylase) are regularly found most numerous and active in the nuclear and supra-nuclear area of the ependymal part. These enzymes are less active in both the other ependymal regions. - Uridine-diphosphoglucose dehydrogenase could not be demonstrated in the SCO. The NADP-linked enzymes of the pentose phosphate shunt, glucose-6-phosphate and 6-phosphogluconate dehydrogenase, show a moderate activity which decreases also from the nuclear towards the apical area of the ependymal cells of the SCO. Enzymes of the glycolytic pathway, such as glucosephosphate isomerase, fructose-6-phosphate kinase, fructose-I,6-diphosphate aldolase, glyceraldehyde-3-phosphate and lactate dehydrogenase, are highly active in the SCO and are located mainly in the supranuclear area, too. Fructose-1,6-diphosphatase could not be demonstrated thus indicating that in the SCO the pathway is most probably only glycolytic but not gluconeogenetic. Compared to the ependyma of the ventricular wall and of the choroid plexus, in the SCO the M type subunits of lactate dehydrogenase predominate. Glycolytic enzymes are also very active in the choroid plexus but less in the ciliated ependyma. Compared to the ciliated ependyma and especially to the ependyma of the choroid plexus, the activities of enzymes which are only present in mitochondria (NAD-linked isocitrate dehydrogenase, succinate dehydrogenase, NAD-linked malate dehydrogenase after preextraction, cytochrome oxidase, 3-hydroxybutyrate and glycerolphosphate and glutamate dehydrogenase) are relatively low. Mitochondria are accumulated near the superior pole of the nuclei as well as in the most apical part of the ependymal cells. - The staining pattern of NADP-linked isocitrate and malate dehydrogenase as well as of NADH dehydrogenase suggests that these enzymes are localized both in and out of mitochondria. The extramitochondrial activity of the first two enzymes might be localized in the cytosol. The extramitochondrial activity of NADH dehydrogenase might be localized in the endoplasmic reticulum...
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PMID:Enzymatic organization of the subcommissural organ. 123 49


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