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)

Some highly purified glycolytic enzymes have been subjected to isoelectric focusing and found to contain a number of enzymatically active species. Crystalline aldolase A and glyceraldehyde-3-phosphate dehydrogenase from rabbit muscle were resolved into five components, crystalline aldolase from yeast was resolved into three components, pyruvate kinase from rabbit muscle yielded four components, and yeast enolase was resolved into two components. Rabbit muscle lactate dehydrogenase (M(4)) gave one major peak of protein and enzymatic activity. The profiles of aldolase, glyceraldehyde-3-phosphate dehydrogenase, and yeast aldolases suggest random combinations of two closely related subunits into tetramers and dimers, respectively. The molecular heterogeneity of the other enzymes is not so easily related to subunit structure.
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PMID:Heterogeneity of presumably homogeneous protein preparations. 580 37

Administration of leupeptin to rats induces the accumulation of numerous autophagic vacuoles in the liver. Furuno et al. (Furuno, K., Ishikawa, T., and Kato, K. (1982) J. Biochem. (Tokyo) 91, 1485-1494) have recently devised a method for Percoll density gradient equilibrium fractionation of crude lysosomal fractions to isolate a highly enriched preparation of autophagic vacuoles. This system was used to determine whether cytoplasmic enzymes are normally sequestered into autophagic vacuoles in fed animals. Within 30 min following the administration of leupeptin to fed rats, several cytoplasmic enzymes could be demonstrated in vacuolar fractions heavier than mitochondria and normal lyosomes. The activities of tyrosine aminotransferase and lactic dehydrogenase as well as antigens of fructose-bisphosphate aldolase were detectable in fractions with densities of 1.115 to 1.15 g/ml containing cathepsins and acid phosphatase. The cytoplasmic enzymes in these fractions exhibited latency and were sequestered within membranous organelles. Six hours after the administration of leupeptin, the autophagic vacuoles gradually disappeared from these fractions concurrently with the loss of both cytoplasmic and lysosomal marker enzymes. For 6 h after injection of leupeptin the activities of cathepsin D and acid phosphatase increased in autophagic vacuoles and decreased in the postvacuolar lysosomal fraction. Administration of dexamethasone, which induces the synthesis of tyrosine aminotransferase and cytosolic aspartate aminotransferase, selectively increased the sequestration of these enzymes to proportional degrees. Cycloheximide administered simultaneously with leupeptin rapidly inhibited formation of autophagic vacuoles and the sequestrations of both cytoplasmic and lysosomal enzymes. However, when cycloheximide was administered 1 h after leupeptin, the formation of autophagosomes and the sequestration of cytoplasmic enzymes were inhibited but the vacuolar uptake of acid phosphatase and cathepsin D continued to increase for several hours. When cycloheximide was injected 1 h after leupeptin, losses of lactic dehydrogenase and aldolase proteins were observed in autophagic vacuoles isolated 1 and 2 h later.
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PMID:Sequestration of cytoplasmic enzymes in an autophagic vacuole-lysosomal system induced by injection of leupeptin. 613 57

Radioimmunoassays specific for fructose-1, 6-diphosphate aldolase isozymes were developed for the quantification of human aldolase A, B and C. The method is a double-antibody radioimmunoassay using radioiodinated purified aldolase A, B and C as ligand, chicken antibodies to aldolase A, B and C, and rabbit antibodies to chicken IgG. The Iodogen method was used for the iodination of aldolase A, B and C in this study. Aldolase A was predominantly high in concentration in muscle, aldolase B was high in normal adult liver, and aldolase C was high in adult brain. Aldolase A was elevated in hepatoma tissue and hepatoma cell lines, where aldolase B was distinctly low. Normal serum levels for the three isozymes were determined. The aldolase A levels in serum obtained from 41 normal subjects were 170 +/- 39 ng/ml. Serum aldolase A levels were increased in many patients with cancer and muscle diseases, but were not increased in patients with hepatitis or other benign diseases. Serum aldolase B levels obtained from 11 normal subjects were 28.5 +/- 9.2 ng/ml. Serum aldolase B levels were increased in patients with hepatitis and correlated well with serum GPT levels. Serum aldolase C levels obtained from 12 normal subjects were 2.4 +/- 0.7 ng/ml. The determination of aldolase A, B and C by radioimmunoassay may be a valuable tool in biochemical and clinical studies of aldolase isozymes.
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PMID:Subunit-specific radioimmunoassay for aldolase A, B, and C subunits: clinical significance. 632 58

The expression of aldolase A and B mRNAs during azo-dye-induced carcinogenesis in rat liver was examined. After feeding the dye for 18 weeks, the level of aldolase A mRNA increased to about 11 times that in a normal liver, with the concomitant decrease of aldolase B mRNA level to about 25% of that in a normal liver. These changes did not occur progressively during the carcinogenesis, but occurred as an additional phase after 4 week-feeding of the azo-dye. At this stage, the levels of aldolase A and B mRNAs were about 7 times and 45% of that in a normal liver, respectively. This biphasic pattern in the aldolase isozyme expression in the azo-dye-fed rat liver is discussed together with the kinetic data of the enzyme activity.
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PMID:Changes of aldolase A and B messenger RNA levels in rat liver during azo-dye-induced hepatocarcinogenesis. 643 99

Aldolase activity with the two substrates fructose-1-phosphate and fructose-1,6-diphosphate was measured in the homogenate of small intestinal biopsy specimens from children with different malabsorptive diseases (celiac disease, cow's milk protein intolerance, infectious diarrhea, giardiasis, and Crohn's disease) and controls. It is demonstrated that the ratio of fructose-1,6-diphosphate/fructose-1-phosphate activity, which reflects the relative amounts of the crypt enzyme aldolase A (EC 4.1.2.13) and the villous enzyme aldolase B (EC 4.1.2.7), correlates very well with both the ratio of crypt to villous height (correlation factor r = 0.92) and the mitotic index (r = 0.80).
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PMID:Biochemical quantification of crypt hyperplastic villous atrophy by aldolase activity assay. 648 61

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

When a 25-50% ammonium-sulphate-insoluble fraction from a bovine brain preparation was chromatographed on a cellulose phosphate column, several protein fractions which inhibit the activity of tubulinyl-tyrosine carboxypeptidase were obtained. One of these fractions exhibited activity of fructose-bisphosphate aldolase (EC 4.1.2.13) and the enzyme accounted for more than 95% of the protein of this fraction as judged by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The inhibitory activities of the two protein fractions which had the highest activity per mg of protein were practically abolished by pretreatment with pronase; preincubation with trypsin, on the other hand, caused only a partial inactivation of the inhibitors. The inhibitory activities were little affected by heating at 90 degrees C for 5 min. Preincubation with purified tubulinyl-tyrosine carboxypeptidase caused a great decrease of the inhibitory activities of these two fractions, leaving open the possibility that these inhibitors act as substrates of the carboxypeptidase.
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PMID:Inhibition of brain tubulinyl-tyrosine carboxypeptidase by endogenous proteins. 651 89

The regulation of aldolase isozyme expression during development was studied by measuring the concentrations of mRNAs coding for aldolase A and B subunits in fetal and adult rat liver. Poly(A)-containing RNAs were extracted from livers at various stages of development of fetal rats, and the aldolase A and B subunits in the in vitro translation products of these RNAs were analyzed immunologically. The content of aldolase B mRNA in 14-day fetal liver, measured quantitatively as translational activity, was somewhat smaller than that of aldolase A mRNA; immunologically precipitable aldolase B and A amounted to 0.06% and 0.25% respectively, of the total products. Similar experiments using RNAs from fetuses at later stages, however, showed that aldolase B mRNA increased during development, whereas aldolase A mRNA decreased. In newborn rat liver, aldolase B constituted 0.56% of the total translation products of mRNA, but there was little detectable aldolase A (0.03%). The changes of aldolase mRNA levels were analyzed further by northern blot and dot-blot hybridization experiments using cloned aldolase A and B cDNAs. The content of aldolase B mRNA increased in the fetal stage, and that in newborn rat liver was about 12 times that in 14-day fetal liver. In contrast, the aldolase A mRNA content decreased during gestation and that in newborn rat liver was about one-eighth of that in 14-day fetal liver. These observations suggest that the switch of aldolase isozyme expression in fetal liver is controlled by the levels of the respective mRNAs.
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PMID:Expression of aldolase isozyme mRNAs in fetal rat liver. 654 71

The activities of six different enzymes were compared in 29 normal, 34 dysplastic, and 80 cancerous (both primary and metastatic) human breast tissues; in MCF-7 cells; and in primary rat mammary tumors. Benign lesions generally showed enzyme activities similar to those of normal breast tissues. Malignant tumors had significantly increased activities of lactate dehydrogenase (LDH), malate dehydrogenase (MDH), fructose-bisphosphate aldolase, hexokinase (HK), pyruvate kinase (PK), and creatine kinase. Enzyme activity in the malignant tumor was always higher than that in apparently normal or fibrocystic tissue from the same patient. Enzyme activities did not correlate with the levels of estrogen and progesterone receptors. LDH, MDH, and HK were elevated to a similar extent in all the tissues examined. Conversely, PK was elevated to a much greater extent in cancerous tissues, particularly in MCF-7 cells. The elevated activities of these enzymes may have diagnostic potential, especially when tumor tissue and apparently normal tissue from the same patient are compared.
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PMID:Enzyme activities in normal, dysplastic, and cancerous human breast tissues. 658 10

Several aldolase B clones from a human liver cDNA library have been identified by using a rabbit aldolase A cDNA as a hybridization probe. The most complete of these, pHL413, is 1389 base pairs long and covers approximately equal to 80% of the length of the mRNA, including 90% of the translated region. The cDNA, pHL413, was used to identify a genomic clone, lambda HG313, which encoded the remaining amino acids of human aldolase B. We demonstrate that the amino acid and nucleotide sequences of aldolase are strongly conserved even between different isozymes. Furthermore, in the 3'-untranslated regions of the mRNAs for the B isozyme of human and rat there is an extensive stretch of homology. Aldolase B lacks a cysteine at positions 72 and 338 and lacks a histidine at position 361. These residues, which are present in rabbit aldolase A, have previously been proposed to take part in catalysis. Our findings suggest that this may not be the case.
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PMID:Complete amino acid sequence for human aldolase B derived from cDNA and genomic clones. 658 24


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