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)

The neutral lipid accumulation in myo-inositol deficient Saccharomyces carlsbergensis results at least partly from an enhancement of acetyl CoA carboxylase activity due to the high level of fructose 1,6-biphosphate which activates acetyl CoA carboxylase, and due to the low level of citrate which counteracts the activation [4]. In an attempt to explore the effect of myo-inositol deficiency on the metabolic fluxes, various enzyme activities were compared between the myo-inositol supplemented and deficient cells. The activities of phosphofructokinase and ATP-citrate lyase increased by 74 and 83%, respectively. The activity of glucose-6-phosphate dehydrogenase was unchanged. Unlike acetyl CoA carboxylase, elimination of low molecular effectors had no influence on their activities. The thermostability of phosphofructokinase (at 53 degrees C) increased, while that of aldolase (at 48 degrees C) greatly decreased due to the deficiency. The thermostability of glucose-6-phosphate dehydrogenase (at 52 degrees C) was also unchanged.
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PMID:The fluctuation of various enzyme activities due to myo-inositol deficiency in Saccharomyces carlsbergensis. 2 19

1. The regulation of glycolysis and pyruvate oxidation under varying conditions of ATP and oxygen consumption was studied in isolated perfused rat hearts. Potassium-induced arrest was employed to inhibit the ATP consumption of the heart. 2. Under the experimental conditions, the beating heart used solely glucose as the oxidisable substrate. The glycolytic flux through the aldolase step decreased in pace with the decreasing oxygen consumption during the potassium-induced arrest of the heart. The decrease in glucose oxidation was larger than the inhibition of the oxygen consumption, suggesting that the arrested heart switches to fatty acid oxidation. The time course and percentage changes of the inhibition of pyruvate oxidation and the decrease in the amount of the active form of pyruvate dehydrogenase suggest that the amount of active pyruvate dehydrogenase is the main regulator of pyruvate oxidation in the perfused heart. 3. To test the relative significance of the possible mechanisms regulating covalent interconversions of pyruvate dehydrogenase, the following parameters were measured in response to the potassium-induced cardiac arrest: concentrations of pyruvate, acetyl-CoA, CoA-SH, citrate, alpha-oxoglutarate, ATP, ADP, AMP, creatine, creatine phosphate and inorganic phosphate and the mitochondrial NADH/NAD+ ratio. In cardiac tissue the adenylate system is not a good indicator of the energy state of the mitochondrion, even when the concentrations of AMP and free cytosolic ADP are calculated from the adenylate kinase and creatine kinase equilibria. Only creatine phosphate and inorganic phosphate undergo significant changes, but evidence of the participation of the latter compounds in the regulation of the pyruvate dehydrogenase interconversions is lacking. The potassium-induced arrest of the heart resulted in a decrease in pyruvate, a slight increase in acetyl-CoA, a large increase in the concentration of citrate and an increase in the mitochondrial NADH/NAD+. The results can be interpreted as showing that in the heart, the pyruvate dehydrogenase interconversions are mainly regulated by the pyruvate concentration and the mitochondrial redox state. Concentrations of all the regulators tested shifted to directions which one would expect to result in a decrease in the amount of active pyruvate dehydrogenase, but the changes were quite small. Therefore, the energy-linked regulation of pyruvate dehydrogenase in intact tissue is possibly mediated by the equilibrium relations between the cellular redox state and the phosphorylation potential recently confirmed in cardiac tissue.
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PMID:Energy-linked regulation of glucose and pyruvate oxidation in isolated perfused rat heart. Role of pyruvate dehydrogenase. 18 44

A 16-year-old boy with a two-year history of recurrent attacks of myalgia, muscle cramps without weakness, and myoglobinuria was shown to have a deficiency in muscle carnitine palmityltransferase. Serum concentrations of creatinine phosphokinase, serum glutamic oxalacetic transaminase, and aldolase were elevated. An electromyogram was consistent with a nonspecific myopathy as were microscopic and ultrastructural examinations of biopsied muscle. Venous lactic acid response to ischemic exercise was compatible with paroxysmal idiopathic myoglobinuria. Activities of muscle phosphorylase A and B, phosphofructokinase, muscle palmityl CoA synthetase, carnitine, and serum carnitine were normal as was the glycogen content. Activity of muscle carnitine palmityltransferase (2.7 microM/minute/mg protein), as measured by a spectrophotometric method and by radioactive assay, was significantly reduced when compared to normal control subjects (14.5 microM/minute/mg protein) and ischemic control subjects (13.8 microM/minute/mg protein). Muscle carnitine acetyltransferase (13.4 microM/minute/mg protein) was approximately 50% of normal control values (25.5 microM/minute/mg protein). This is the third reported case of myoglobinuria in a patient associated with a deficiency of muscle carnitine palmityltransferase activity.
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PMID:Recurrent myoglobinuria and muscle carnitine palmityltransferase deficiency. 87 82

The effect of hemineurin on the clinical picture and the course of severe forms of delirium tremens was studied over time in 28 male patients who were simultaneously examined for the enzymic activity of the liver and parameters of the cholinergic system. The activity of alanine (AlAT) and aspartate aminotransferases (AsAT), sorbite dehydrogenase (SorDH), fructose-1-phosphate aldolase, blood acetylcholine (AC) levels, the activity of acetylcholine esterase in the whole blood (ACWB) and acetylcholine esterase of red blood cells (ACRC) determined in the course of treatment showed that hemineurin, in addition to a marked sedative effect, contributed to rapid normalization of liver function and carbohydrate metabolism. The effect of hemineurin helped to restore the synthesis and acetylation of CoA, to stimulate AC metabolism, and to set a relative balance of the mediator systems, ensuring the prevention of dangerous complications (acute cardiovascular insufficiency, cerebral edema) in severe cases of delirium tremens.
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PMID:[Effect of heminevrin on the functional status of the liver and cholinergic system during treatment of severe forms of alcoholic delirium]. 370 30

The alpha-ketoglutarate dehydrogenase complex of either pig heart or Escherichia coli catalyzes a NAD- and CoASH-dependent oxidation of 2-keto-4-hydroxyglutarate which is stereoselective toward the L-isomer of this hydroxyketo acid. L-Malyl-CoA is the product of the reaction; the evidence includes observing (a) a steady increase in absorbance at 230 nm during the oxidation of 2-keto-4-hydroxyglutarate, (b) a positive response of oxidation reaction mixtures to neutral hydroxylamine, (c) loss of the two foregoing results concomitant with release of thiol-reacting material and the formation of free malate when reaction mixtures are heated, (d) formation of a hydroxamate which has chromatographic mobilities identical to that of chemically synthesized malate hydroxamate, (e) enzymatic formation of a radioactive product from 14C-labeled 2-keto-4-hydroxyglutarate which co-migrates with chemically synthesized malyl-CoA, and (f) hydrolysis of the product by citrate synthase, an enzyme absolutely specific for citryl-CoA and L-malyl-CoA. A 1:1:1 stoichiometric relationship exists between the amount of 2-keto-4-hydroxyglutarate oxidized, NAD reduced, and malate (or malyl-CoA) formed. Results from studies in which either 14C-labeled 2-keto-4-hydroxyglutarate, pyruvate, or glyoxylate is incubated with mixtures of purified enzymes or extracts of E. coli support the suggestion that the aldolase which preferentially catalyzes formation of L-2-keto-4-hydroxyglutarate from pyruvate plus glyoxylate in E. coli is coupled with the oxidative decarboxylation of this substrate, as reported here, and other enzymes in a multistep pyruvate-catalyzed cyclic oxidation of glyoxylate.
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PMID:Malyl-CoA formation in the NAD-, CoASH-, and alpha-ketoglutarate dehydrogenase-dependent oxidation of 2-keto-4-hydroxyglutarate. Possible coupled role of this reaction with 2-keto-4-hydroxyglutarate aldolase activity in a pyruvate-catalyzed cyclic oxidation of glyoxylate. 638 79

2-Amino-3-ketobutyrate ligase catalyzes the reversible, pyridoxal 5'-phosphate-dependent condensation of glycine with acetyl CoA forming the unstable intermediate, 2-amino-3-ketobutyrate. Several independent lines of evidence indicate that the pure protein obtained in the purification of this ligase from Escherichia coli also has L-threonine aldolase activity. The evidence includes: (a), a constant ratio of specific activities (aldolase/ligase) at all stages of purifying 2-amino-3-ketobutyrate ligase to homogeneity; (b), the same rate of loss of aldolase and ligase activities during controlled heat inactivation of the pure protein at 60 degrees C in the absence, as well as in the presence of acetyl CoA, a protective substrate; (c), ratios of the two enzymatic activities that are not significantly different during slow inactivation by iodoacetamide, with and without L-threonine added; (d), coincident rates of loss and essentially identical rates of recovery of aldolase activity and ligase activity during resolution of the holoenzyme with hydroxylamine followed by reconstitution with pyridoxal 5'-phosphate. No aldolase activity is observed with D-threonine as substrate and L-allothreonine is about 25% as effective as L-threonine. Whereas ligase activity has a sharp pH optimum at 7.5, the aldolase activity of this pure protein is maximal at pH 9.0. Comparative apparent Km values for glycine (ligase) and L-threonine (aldolase) are 10 mM and 0.9 mM, respectively, whereas corresponding respective Vmax values were found to be 2.5 mumol of CoA released/min per mg vs. 0.014 mumol of acetaldehyde formed (NADH oxidized)/min per mg.
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PMID:Identity and some properties of the L-threonine aldolase activity manifested by pure 2-amino-3-ketobutyrate ligase of Escherichia coli. 834 29

The final two steps in the dmp operon-encoded meta-cleavage pathway for phenol degradation in Pseudomonas sp. strain CF600 involve conversion of 4-hydroxy-2-ketovalerate to pyruvate and acetyl coenzyme A (acetyl-CoA) by the enzymes 4-hydroxy-2-ketovalerate aldolase and aldehyde dehydrogenase (acylating) [acetaldehyde:NAD+ oxidoreductase (CoA acetylating), EC 1.2.1.10]. A procedure for purifying these two enzyme activities to homogeneity is reported here. The two activities were found to copurify through five different chromatography steps and ammonium sulfate fractionation, resulting in a preparation that contained approximately equal proportions of two polypeptides with molecular masses of 35 and 40 kDa. Amino-terminal sequencing revealed that the first six amino acids of each polypeptide were those deduced from the previously determined nucleotide sequences of the corresponding dmp operon-encoded genes. The isolated complex had a native molecular mass of 148 kDa, which is consistent with the presence of two of each polypeptide per complex. In addition to generating acetyl-CoA from acetaldehyde, CoA, and NAD+, the dehydrogenase was shown to acylate propionaldehyde, which would be generated by action of the meta-cleavage pathway enzymes on the substrates 3,4-dimethylcatechol and 4-methylcatechol. 4-Hydroxy-2-ketovalerate aldolase activity was stimulated by the addition of Mn2+ and, surprisingly, NADH to assay mixtures. The possible significance of the close physical association between these two polypeptides in ensuring efficient metabolism of the short-chain aldehyde generated by this pathway is discussed.
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PMID:Purification and properties of the physically associated meta-cleavage pathway enzymes 4-hydroxy-2-ketovalerate aldolase and aldehyde dehydrogenase (acylating) from Pseudomonas sp. strain CF600. 841 88

The immunologic relatedness of various cofactor-binding sites of enzymes requiring different nucleotide cofactors was examined. Chicken antibodies specific for NADPH- or CoA-binding domains were raised using an NADPH- or CoA-requiring enzyme as an immunogen. Antibodies specific for either NADPH- or CoA-binding domains were isolated by immunoaffinity chromatography of the respective antisera using unrelated NADPH- or CoA-requiring enzymes as affinity ligands. The reactivities of the NADPH- and CoA-binding-site-specific antibodies with a variety of enzymes that required different cofactors was shown on Western blots of SDS-PAGE of the enzymes. Variable cross-reactivities were observed among all nucleotide-cofactor requiring enzymes with each specific cofactor-domain-antibody population. Numerous proteins not physiologically associated with nucleotide cofactors, including acyl carrier protein, were completely unreactive. Proteins that bound phosphoryl compounds either as substrates or cofactors showed varying degrees of reactivity with each population of specific antibodies. These included aldolase, ribulose-1,5-bisphosphate carboxylase/oxygenase, ribonuclease A, carbonic anhydrase and triosephosphate isomerase. The immunologic cross-reactivity suggested that these proteins share a common structural feature, probably a primary structure epitope, since the proteins had been subjected to denaturing polyacrylamide gel electrophoresis. A candidate for this common structural feature is a glycine-rich sequence comprising a phosphate binding loop.
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PMID:Nucleotide cofactor-binding-domain-specific antibodies show immunologic relatedness among unrelated proteins that bind phosphoryl compounds. 845 96

The gene loci fcs, encoding feruloyl coenzyme A (feruloyl-CoA) synthetase, ech, encoding enoyl-CoA hydratase/aldolase, and aat, encoding beta-ketothiolase, which are involved in the catabolism of ferulic acid and eugenol in Pseudomonas sp. strain HR199 (DSM7063), were localized on a DNA region covered by two EcoRI fragments (E230 and E94), which were recently cloned from a Pseudomonas sp. strain HR199 genomic library in the cosmid pVK100. The nucleotide sequences of parts of fragments E230 and E94 were determined, revealing the arrangement of the aforementioned genes. To confirm the function of the structural genes fcs and ech, they were cloned and expressed in Escherichia coli. Recombinant strains harboring both genes were able to transform ferulic acid to vanillin. The feruloyl-CoA synthetase and enoyl-CoA hydratase/aldolase activities of the fcs and ech gene products, respectively, were confirmed by photometric assays and by high-pressure liquid chromatography analysis. To prove the essential involvement of the fcs, ech, and aat genes in the catabolism of ferulic acid and eugenol in Pseudomonas sp. strain HR199, these genes were inactivated separately by the insertion of omega elements. The corresponding mutants Pseudomonas sp. strain HRfcsOmegaGm and Pseudomonas sp. strain HRechOmegaKm were not able to grow on ferulic acid or on eugenol, whereas the mutant Pseudomonas sp. strain HRaatOmegaKm exhibited a ferulic acid- and eugenol-positive phenotype like the wild type. In conclusion, the degradation pathway of eugenol via ferulic acid and the necessity of the activation of ferulic acid to the corresponding CoA ester was confirmed. The aat gene product was shown not to be involved in this catabolism, thus excluding a beta-oxidation analogous degradation pathway for ferulic acid. Moreover, the function of the ech gene product as an enoyl-CoA hydratase/aldolase suggests that ferulic acid degradation in Pseudomonas sp. strain HR199 proceeds via a similar pathway to that recently described for Pseudomonas fluorescens AN103.
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PMID:Biochemical and genetic analyses of ferulic acid catabolism in Pseudomonas sp. Strain HR199. 1054 94

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


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