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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 quantitative and qualitative changes in fructose-P2 aldolase isoenzyme concentrations during development of "red" (leg) and "white" (breast) skeletal muscles of the chick were investigated. (a) The aldolase C to A subunit transition associated with muscle development is accompanied by large increases in aldolase activity (units/g, wet weight) and in specific catalytic activity (units/mg of protein). The accumulations in both muscle types follow pseudo-first order kinetics with doubling times of 2 to 3 days. The steady state level of aldolase activity in breast muscle (about 150 units/g) is approximately 4-fold higher than that in leg muscle (about 40 units/g). In contrast to leg muscle, the major increase in aldolase activity in breast muscle occurs during postembryonic development. (b) Immunotitration studies demonstrated a direct correlation between increases in enzyme activity and aldolase A subunits during postembryonic muscle development. It was calculated that under steady state conditions, aldolase A4 comprises about 1 percent and 0.26 percent, respectively, of the total wet weight of breast and leg muscle. (c) regulation at the level of protein synthesis in effecting the postembryonic accumulation of aldolase A4 in the muscle types was investigated in short term amino acid incorporation experiments. After a 1-hour pulse with [3H]leucine, aldolase from breast and leg muscle was isolated in a single step by affinity chromatography on phosphocellulose. Incorporation of tritum into aldolase A4 and into soluble or total protein was compared. Between 4 and 38 days after hatching, the rate of aldolase synthesis relative to the synthesis of soluble muscle protein increased about 7- and 3-fold, respectively, in breast and leg muscle. Relative to total protein, incorporation of [3H]leucine into A4 increased about 3-fold in breast muscle, and decreased slightly in leg muscle between 5 and 25 days after hatching. By 3 weeks after hatching, incorporation of [3H]leucine into aldolase A4 relative to incorporation into total protein was about 6-fold higher in breast muscle than it was in leg muscle. The present work, as well as other recent studies, are discussed in relation to the mechanism involved in controlling tissue-specific and stage-specific levels of aldolase isoenzymes in animal cells.
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PMID:Ontogeny and regulation of fructose diphosphate aldolase isoenzymes in "red" and "white" skeletal muscles of the chick. 80 78

The kinetic parameters of fructose bisphosphate aldolase (EC 4.1.2.13) were shown to be modified on binding of the enzyme to the actin-containing filaments of skeletal muscle. Although binding to F-actin or F-actin-tropomyosin filaments results in relative minor changes in kinetic properties, binding to F-actin-tropomyosin-troponin filaments produces major alterations in the kinetic parameters, and, in addition, renders them Ca2+-sensitive. These observations may be relevant to an understanding of the function of this enzyme within the muscle fibre.
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PMID:Modification of the kinetic parameters of aldolase on binding to the actin-containing filaments of skeletal muscle. 88 71

The results of a double isotope experiment using 3H- and 14C-labeled leucine as precursors of protein synthesis demonstrated that the aldolase C to A subunit transition which is associated with chick skeletal muscle development involves the preferential synthesis of different aldolase isoenzymes. This developmental system was used to test for subunit exchange between aldolase tetramers in vivo. In a second double isotope experiment, it was found that the 14C:3H ratios of A and C subunits derived from the same heterotetramer were essentially identical, while the isotope ratios of the same subunit type derived from different isoenzymes were considerably different. Had subunit exchange between the isoenzymes occurred, A subunits of a given heterotetramer would have been expected to have higher isotope ratios than the corresponding C subunits. Therefore, these data suggest that subunit exchange between aldolase tetramers does not occur in vivo, at least not in skeletal muscle to an appreciable extent. The results of the present study suggest that all aldolase tetramers are constructed at the time of the initial assembly of newly synthesized subunits, that is, "new" tetramers would not be generated by subunit exchange between already constructed tetramers. In addition, the present work suggests that the degradation of all four subunits of an aldolase tetramer are coupled inasmuch as the subunits would not be reincorporated into other tetramers. Thus, in contrast to some other proteins, it appears that the subunits of the aldolase tetramer turn over coordinately.
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PMID:Evidence for the lack of subunit exchange between aldolase tetramers in vivo. 116 46

Three aldolase isoenzymes; aldolase A, B and C were found in various human tissues including gastric mucosa, by means of substrate specificities (the fuctose-1, 6-diphosphate aldolase/fructose-1-phosphate aldolase activity ratio) and electrophoresis. The basic pattern of aldolase isoenzyme in man consisted of nine active bands, which were designated as I, II, III, IV, V, VI, VII, VIII and IX band from anode side respectively. The I band corresponded to aldolase C, V to aldolase A and IX to aldolase B. The II, III and IV band are hybrid molecules composed of subunit of aldolase A and C, and the VI, VII and VIII of subunit of aldolase A and B. The V band was present in all tissues, while IX was detected in the liver, kidney and stomach. The I, II, III and IV band were found in all tissues except for muscle. These findings were extremely different from those in other species. In normal gastric mucosa, active bands were composed of I, II, III, IV, V, VIII and IX band, while in gastric cancerous tissue, I, II, III, VIII and IX band were absent or markedly decreased in activity. In contrast, the V band increased. In fetal gastric mucosa, they showed the same pattern as cancerous. In extract of cancerous tissues, the FDP/F1P activity ratio was 20.5+/-2.2, as compared with 7.2+/-0.1 in normal gastric mucosa. In serum of patients with gastric cancer, the FDP/F1P activity ratio was 9.7+/-1.2, while it was 2.9+/-0.4 in normal human serum. These results suggest that the elevation in serum of the FDP/F1P ratio in gastric cancer is due to increase in muscle type isoenzyme (aldolase A) which is derived from cancerous tissue. Furthermore, the analysis of serum aldolase isoenzyme will save for cancer diagnosis.
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PMID:[The distribution of the aldolase isoenzymes in various human tissues and the anomaly in cancerous tissues -especially in gastric cancer- (author's transl)]. 124 Aug 53

To assess changes in aldolase isozyme patterns (A, B, and C) in renal cell carcinoma (RCC) tissues and to evaluate whether serum aldolase A might be a useful marker for RCC, quantitative analysis by enzyme immunoassay and immunohistochemical localization were performed. Concentrations of aldolase A in RCC (7300 +/- 6300 ng./mg. protein n = 26) were significantly higher than those of normal cortex (720 +/- 410 ng./mg. protein, n = 14, p less than 0.01); concentrations of aldolase C in RCC (48.0 +/- 8.0 ng./mg. protein) were also significantly higher than those of normal cortex (8.7 +/- 4.7 ng./mg. protein, p less than 0.01). On the other hand, concentrations of aldolase B in normal cortex were 18,100 +/- 10,100 ng./mg. protein (n = 14), whereas the values in RCC were only 130 +/- 270 ng./mg. protein, a significant lowering (p less than 0.01). Immunohistochemically, aldolases A and C were found localized in all RCC tissues (n = 10); aldolase B was faintly stained in only a few tumor cells of two cases (20%). Levels of serum aldolase A were elevated (greater than 300 ng./ml.) in 30 (75%) of 40 patients with RCC as compared to three (6.3%) of 48 individuals with urogenital benign diseases and in seven (21%) of 34 cases with non-RCC urogenital malignancies. Since it is generally accepted that RCC are derived from renal proximal tubules, these findings indicate that aldolase B, the predominant isozyme in the normal case, changes into aldolases A and C during carcinogenesis and that serum aldolase A could be a new useful biomarker for RCC.
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PMID:An immunochemical and immunohistochemical study of aldolase isozymes in renal cell carcinoma. 185 54

A genomic clone was isolated which codes for the fructose bisphosphate aldolase of Plasmodium falciparum. The aldolase gene is interrupted by one intron which divides the coding region into two exons. The first one codes for one amino acid only, the initiation methionine, while the second one encodes the residual 368 amino acids of the protein. The gene, which is represented only once in the genome, is transcribed at high rates as a 2.4-kb mRNA in the P. falciparum blood stage. The aldolase gene encodes a protein of 40,105 Da, which is 61-68% homologous to known eukaryotic aldolases. The protein was expressed in Escherichia coli cells in an unfused and enzymatically active form. Antisera raised against amino acids 9-96 recognize a 41-kDa protein band previously shown to protect monkeys against a P. falciparum infection. These antisera cross-react with aldolases of different species, which confirms the strong conservation of this enzyme during evolution. The aldolase could be localized in the cytoplasm of the parasite as an active and soluble form. An inactive form was found to be associated with the membrane fraction. Digestion data with phospholipase C suggest a membrane association of this polypeptide via a glycosylphosphatidylinositol anchor.
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PMID:Plasmodium falciparum aldolase: gene structure and localization. 219 85

A subunit specific radioimmunoassay was developed for the quantification of human aldolase A, B, and C. The method used was a double antibody radioimmunoassay using radioiodinated purified aldolase A, B, or C subunits as the ligand, specific chicken antibodies to aldolase isozymes and rabbit antibodies to chicken IgG. The Iodogen method was used for iodination of the purified isozyme subunits in this study. Human brain tissue contained similar concentrations of aldolase A and aldolase C, and a smaller amount of aldolase B, which was the main isozyme of liver tissue. Levels of serum aldolase A were greater than 203 ng/ml, the upper limit of normal, in six of 24 patients with cerebral infarction and in 11 of 31 patients with cerebral hemorrhage. Nine of 24 patients with cerebral infarction and 16 of 31 patients with cerebral hemorrhage had serum aldolase C levels greater than 4.1 ng/ml, the upper limit in normal sera. These data suggest that serum aldolase C may be a more specific and sensitive marker of cerebrovascular diseases than aldolase A. We also demonstrated that serial measurement of serum aldolase C in patients with cerebrovascular diseases might be useful in estimating prognosis, since serially increasing serum aldolase C levels during the course of these diseases were correlated with a high mortality rate.
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PMID:Serum aldolase isozyme levels in patients with cerebrovascular diseases. 224 17

The fructose bisphosphate aldolase genes of Trypanosoma brucei are interspersed with unrelated genes whose transcript levels show no developmental modulation. Transcription appears approximately constant across the entire locus, suggesting that aldolase mRNA abundance is regulated post-transcriptionally.
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PMID:The genes encoding fructose bisphosphate aldolase in Trypanosoma brucei are interspersed with unrelated genes. 234 93

Fructose-bisphosphatase-deficient mutants of mucoid Pseudomonas aeruginosa were isolated by ethyl methanesulfonate mutagenesis using gluconate as the nonpermissive substrate, and all the sixty isolates possessed 10-30% of the parental enzyme activity. The mutants had low levels of fructose-biphosphate aldolase activity and could not normally synthesize alginate from any substrate except on Pseudomonas isolation agar plates. The results suggest the essentiality of fructose bisphosphatase activity for the growth or survival of P. aeruginosa and a probable linkage of genes controlling this enzyme with those of fructose bisphosphate aldolase and alginate biosynthesis.
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PMID:Fructose-bisphosphatase-deficient mutants of mucoid Pseudomonas aeruginosa. 254 76

The cDNA clones for rat aldolase C mRNA having the nearly complete length were isolated from a rat brain cDNA library and sequenced. The nucleotide sequence of pRAC2-1, a cDNA clone having the largest cDNA insert, indicates that the cDNA is composed of a 105-base-pair 5'-noncoding sequence, a 1089-base-pair coding-sequence and a 382-base-pair 3'-noncoding sequence. The amino acid sequence of aldolase C deduced from a possible open reading frame was composed of 362 residues having a relative molecular mass of 39,164 excluding the initiating methionine, one amino acid shorter than aldolases A and B. The length of aldolase c mRNA was 1750 residues, somewhat longer than that of the aldolase A and B transcripts. The aldolase C mRNA was distributed mainly in the brain, some in ascites hepatoma and fetal liver. Comparison of the amino acid sequences of rat aldolase C with those for rat aldolase A and B [Joh et al. (1985) Gene 39, 17-24; Tsutsumi et al. (1984) J. Biol. Chem. 259, 14572-14575], which have been determined previously, shows the existence of highly conserved stretches of amino acid among the three isozymic forms throughout their sequences. The extent of the homology between aldolases A and C is 81%, while those between aldolases A and B, and B and C are 70%, respectively. The analysis of amino acid substitution among aldolases A, B and C from several species suggests that the isozyme genes diverged much earlier than animal species appeared and that the aldolase C gene has evolved from the aldolase A gene after aldolase A and B genes diverged.
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PMID:The structure of brain-specific rat aldolase C mRNA and the evolution of aldolase isozyme genes. 283 Oct 50


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