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)

A radioimmunoassay was developed for the direct quantification of aldolase A in human serum. The method is a double antibody radioimmunoassay using radioiodinated aldolase A4 homopolymer as ligand, chicken antibodies to aldolase A, and rabbit antibodies to chicken IgG. The lowest measurable amount by this method was 2 ng (0.01 U). The radioimmunoassay was shown to be specific for the aldolase A subunit, with no cross-reactivity with human aldolase B subunits or homopolymeric human aldolase C (C4). The immunoreactive aldolase A in the sera of 41 normal healthy subjects ranged from 130 to 210 ng/ml (0.81-1.31 U/1), with a mean of 171 /+- 39 ng/ml.
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PMID:Radioimmunoassay for human aldolase A. 731 82

A full length cDNA clone representing an aldolase mRNA was isolated from a sea bream (Sparus aurata) liver cDNA library. Sequencing of this clone revealed it to encode a 364 amino acid protein with 74% amino acid identity to human aldolase B and slightly lower similarity to human aldolase A and C. In view of the sequence data and of Northern blot analysis showing strong expression of a 1.6 kb transcript in liver it was concluded that the cloned gene represents aldolase B. This clone represents the first aldolase gene to be sequenced from any fish species thus providing new data on the evolution of the vertebrate aldolase gene family.
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PMID:Cloning and characterisation of a fish aldolase B gene. 763 37

A cytoskeletal fraction of porcine tracheal smooth muscle (PTSM) was found to contain > 90% of total cellular aldolase (fructose 1,6-bisphosphate aldolase, EC 4.1.2.13) activity. PTSM aldolase was purified by DEAE and inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) affinity chromatography and found to react with an antibody directed against human aldolase C, but not anti-aldolase A and B. The molecular mass of native aldolase was about 138 kDa (on Sephacryl S-300); SDS-denatured enzyme was 35 kDa (comigrated with rabbit skeletal muscle aldolase). Total cellular aldolase tetramer (aldolase4) content was 34.5 pmol/100 nmol lipid P(i). Ins(1,4,5)P3) binding activity coeluted with aldolase during Sephacryl 300, DEAE, and Ins(1,4,5)P3 affinity chromatography. Ins(1,4,5)P3 bound to purified aldolase (at 0 degree C) in a dose-dependent manner over the range [Ins(1,4,5)P3] 20 nM to 20 microM, with maximal binding of 1 mol of Ins(1,4,5)P3/mol aldolase4 and a Kd of 12-14 microM. Fru(1,6)P2 and Fru(2,6)P2 displaced bound Ins(1,4,5)P3) with a 50% inhibition at 30 and 170 microM, respectively. Ins(1,3,4)P3 (20 microM) and glyceraldehyde 3-phosphate (2 mM) were also potent inhibitors of Ins(1,4,5)P3 binding, but not inositol 4-phosphate or inositol 1,4-bisphosphate (20 microM each). Aldolase-bound Ins(1,4,5)P3 may play a role in phospholipase C-independent increases in free [Ins(1,4,5)P3].
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PMID:Inositol 1,4,5-trisphosphate binding to porcine tracheal smooth muscle aldolase. 765 22

A procedure has been developed for high-level expression of Trypanosoma brucei fructose-bisphosphate aldolase in Escherichia coli. Therefore, a specific restriction site was introduced by mutagenesis at the front of the gene, enabling its ligation in an expression plasmid, immediately downstream of the regulatory sequences. Growth conditions were established for production of high amounts of soluble and active enzyme. Aldolase was purified to near-homogeneity from the soluble fraction of the bacterial lysate by nuclease treatment, differential precipitation steps, and passage over a CM-Sepharose column. From a 1-liter culture of E. coli cells, 60-120 mg of purified protein that is essentially indistinguishable in physicochemical and kinetic properties and in stability from the enzyme purified from trypanosomes grown in infected laboratory animals was reproducibly obtained.
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PMID:High-level expression of Trypanosoma brucei fructose-1,6-bisphosphate aldolase in Escherichia coli and purification of the enzyme. 775 37

In chickens, as in all vertebrates, tissue-specific expression of aldolase isozymes A, B, and C is developmentally coordinated. These developmental transitions in aldolase expression have been studied most extensively by charting enzyme activity during normal and abnormal development of specific vertebrate tissues. Indeed, aldolase expression has been a key marker for normal differentiation and for retrodifferentiation during carcinogenesis. Aldolase expression during chicken myoblast differentiation offers a model for investigating the regulatory mechanisms of these developmental transitions at the level of gene expression. For these studies, cDNAs encoding the most isozyme-specific regions of both chicken aldolase A and C were cloned. The chicken aldolase A cDNA represents the first report of this sequence. Aldolase steady-state mRNA expression was measured during chicken myoblast differentiation in primary cultures using RNase protection assays with cRNA probes generated from these aldolase cDNA clones. Steady-state mRNA for aldolase C, the predominant embryonic aldolase isozyme in chickens, did not significantly change throughout myoblast differentiation. In contrast, expression of steady-state mRNA for aldolase A, the only aldolase isozyme found in adult-skeletal muscle, was not detected until after myoblast fusion was approximately 50% completed. Aldolase A expression gradually increased throughout myoblast differentiation until approximately 48 h after fusion was completed when there was a dramatic increase. These results are contrasted with those of Turner et al. (1974) [Dev Biol 37:63-89] that showed a coordinated switch in isozyme activities between the embryonic aldolase C and the muscle-specific aldolase A. This discordant expression indicates that the aldolase A and C genes may employ different regulatory mechanisms during myoblast differentiation.
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PMID:Noncoordinate changes in the steady-state mRNA expressed from aldolase A and aldolase C genes during differentiation of chicken myoblasts. 776 78

The time courses of activities of aldolase, glyceraldehyde-3-phosphate dehydrogenase, hexokinase and pyruvate kinase were determined in stimulated rat thymocytes at 24 h intervals during a period of 72 h of culture. In parallel the mRNA levels of these enzymes were analysed by Northern blotting with specific probes. Both the enzyme activities and the corresponding mRNA levels reached their maxima 48 h after stimulation coinciding with the S-phase of the cell cycle. The isozyme types of aldolase and hexokinase in resting and in mitogen-stimulated rat thymocytes were identified by Northern blot hybridisation using isozyme-specific probes. In these cells the aldolase A is expressed, whereas type B and C could not be detected. The transcription of the aldolase A gene can be regulated by two different promoters. Depending on the alternative usage of the promoters the aldolase A-specific mRNA either contains the non-translated exons M1 or AH1. In rat thymocytes the promoter proximal to the exon AH1 is used while the expression of mRNA I, the type characteristic for muscle tissue, was not observed. In contrast to aldolase two isozyme types of hexokinase were detected. Hexokinase I as well as hexokinase II were present in thymocytes whereas hexokinase III was not detectable. A shift in the isozyme pattern was not observed during the cell cycle progression.
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PMID:Expression of glycolytic isozymes in rat thymocytes during cell cycle progression. 780 92

We report the construction of subunit interface mutants of rabbit muscle aldolase A with altered quaternary structure. A mutation has been described that causes nonspherocytic hemolytic anemia and produces a thermolabile aldolase (Kishi H et al., 1987, Proc Natl Acad Sci USA 84:8623-8627). The disease arises from substitution of Gly for Asp-128, a residue at the subunit interface of human aldolase A. To elucidate the role of this residue in the highly homologous rabbit aldolase A, site-directed mutagenesis is used to replace Asp-128 with Gly, Ala, Asn, Gln, or Val. Rabbit aldolase D128G purified from Escherichia coli is found to be similar to human D128G by kinetic analysis, CD, and thermal inactivation assays. All of the mutant rabbit aldolases are similar to the wild-type rabbit enzyme in secondary structure and kinetic properties. In contrast, whereas the wild-type enzyme is a tetramer, chemical crosslinking and gel filtration indicate that a new dimeric species exists for the mutants. In sedimentation velocity experiments, the mutant enzymes as mixtures of dimer and tetramer at 4 degrees C. Sedimentation at 20 degrees C shows that the mutant enzymes are > 99.5% dimeric and, in the presence of substrate, that the dimeric species is active. Differential scanning calorimetry demonstrates that Tm values of the mutant enzymes are decreased by 12 degrees C compared to wild-type enzyme. The results indicate that Asp-128 is important for interface stability and suggest that 1 role of the quaternary structure of aldolase is to provide thermostability.
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PMID:Subunit interface mutants of rabbit muscle aldolase form active dimers. 783

Subunit specific radioimmunoassay for aldolase isozymes were developed for the quantification of human aldolase A and B. Aldolase B immunoreactivities were predominantly high in adult normal liver, while aldolase A was distinctly low. Aldolase A was high, while aldolase B was low in neonatal liver compared with the adult liver. Aldolase A immunoreactivities were almost the same as those of aldolase B in fetal liver (28 weeks). Aldolase A was predominantly found in human hepatoma tissues, whereas aldolase B was distinctly low in the same hepatoma tissues. With regard to human hepatoma cell lines, aldolase A was also predominantly found in HepG2 and PLC/PRF/5 cell lines, whereas aldolase B levels were extremely low. Almost the same results were obtained from mRNA expression of aldolase A and B in human hepatoma cell lines by the method of northern hybridization. Effects of various reagents on differentiation of hepatoma cell lines were investigated. Neither Dimethyl Sulfoxide (DMSO) and 12-O-Tetradecanoylphorbol-13-acetate (TPA), which are known to be the inducers of differentiation of human leukemia cell lines such as HL-60, nor Transforming Growth Factor-beta 1 (TGF-beta 1) and Hepatocyte Growth Factor (HGF), which are known to be growth inhibitors, could cause the differentiation of hepatoma cell lines in the alteration of aldolase isozymes. The same data were shown in mRNA expression of aldolase isozymes. These results suggest that aldolase A immunoreactivities and mRNA expression are both predominantly high in hepatoma cell lines, and the reagents such as DMSO, TPA, TGF-beta 1 and HGF which tried to differentiate the hepatoma cell lines used in this study were not effective in the alteration of aldolase isozymes.
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PMID:[Immunoreactivities and messenger RNA expression of aldolase A and B in human hepatoma cell lines]. 786 61

A Ni(2+)-binding protein (pNiXc, 40 kDa), present in Xenopus laevis oocytes and embryos, was isolated from mature oocytes by chromatography on DEAE-cellulose and cellulose phosphate, followed by FPLC on Ni-iminodiacetate-Agarose, or reverse-phase HPLC on a C-4 column. Size-exclusion HPLC showed that intact pNiXc is approximately 155 kDa, consistent with tetrameric structure. After cleavage with Lys-C proteinase or cyanogen bromide, six peptides were separated by HPLC and sequenced by Edman degradation, providing sequence data for 83 residues. Data-base search showed similarity of pNiXc to eukaryotic aldolases, with 96% identity to human aldolase A. pNiXc demonstrated aldolase activity with fructose 1,6-bisphosphate as substrate (Km, 30 microM Vmax 26 mumol min-1 mg-1); the aldolase activity was inhibited non-competitively by Cu2+, Cd2+, Co2+, or Ni2+. Equilibrium dialysis showed high affinity binding (Kd, 7 microM) of 1 mole of Ni per mole of 40 kDa subunit. Based on metal-blot competition assays, the abilities of metals to compete with 63Ni2+ for binding to pNiXc were ranked: Cu2+ >> Zn2+ > Cd2+ > Co2+. This study identifies pNiXc as the monomer of fructose-1,6-bisphosphate aldolase A, and raises the possibility that aldolase A is a target enzyme for metal toxicity.
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PMID:The 40 kDa 63Ni(2+)-binding protein (pNiXc) on western blots of Xenopus laevis oocytes and embryos is the monomer of fructose-1,6-bisphosphate aldolase A. 787 95

We studied the alteration of aldolase isozymes in the serum and tissues of patients with cancer and other diseases using radioimmunoassays specific for aldolase A, B, and C subunits. Aldolase B was predominantly found in adult liver, where aldolase A and C were distinctly low. Aldolase A and B showed almost the same concentration in fetal liver, while in neonatal liver aldolase B protein concentrations were much higher than aldolase A. In contrast, aldolase A was the predominant isozyme found in hepatoma and gastric cancer tissues, whereas aldolase B was distinctly low in hepatoma tissues, and extremely low in gastric cancer tissues. These results suggest that the aldolase A is a more fetal type of liver isozyme than the aldolase B and C, and aldolase B is a more differentiated type of liver isozyme than aldolase A and C. Serum FDP aldolase activities were elevated in half of patients with liver diseases, all patients with muscle diseases and a few patients with cancer. Serum aldolase A levels were elevated in patients with muscle diseases and cancer, but not elevated in patients with liver diseases. In contrast, serum aldolase B levels were elevated in patients with liver disease, but not elevated in patients with muscle diseases and other diseases without liver injury. Serum aldolase B levels showed a trend to decrease in cancer patients with normal GPT levels. Serum aldolase A/B ratios were significantly increased in cancer patients with normal GPT levels, whereas they showed the decreased levels in patients with liver diseases.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Alteration of aldolase isozymes in serum and tissues of patients with cancer and other diseases. 804 42


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