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 rate of deuterium exchange between [1-(S)-2H]dihydroxyacetone 3-phosphate and the solvent catalyzed by native and metal-substituted yeast aldolases has been measured. In the presence of 0.1 M potassium acetate at 15 degrees C, pH 7.3, the deuterium exchange reaction catalyzed by native yeast aldolase has a kcat of 95 s-1. In contrast to the 7-fold activity enhancement by 0.1 M potassium ion (relative to 0.1 M sodium ion) of the cleavage of D-fructose 1,6-bisphosphate catalyzed by native yeast aldolase, a negligible (1.1-fold) activation by 0.1 M potassium ion is observed in the rate of dedeuteration of [1(S)-2H]dihydroxyacetone 3-phosphate. The order of reactivity of the yeast metalloaldolases in the deuterium exchange roughly parallels that seen in the fructose bisphosphate cleavage reaction. These findings suggest that the carbonyl groups of enzyme-bound D-fructose 1,6-bisphosphate and dihydroxyacetone phosphate are both polarized by the active site divalent metal cation. A mechanistic formulation consistent with the results of this and the previous paper is presented.
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PMID:Role of mono- and divalent metal cations in the catalysis by yeast aldolase. 633 13

Intraperitoneal administration of leupeptin to rats induced a hemoglobin-hydrolyzing protease which was most active at pH 3.5 and was insensitive to pepstatin in various tissues such as the liver, kidney, and muscle, as observed previously in adult rat hepatocytes in primary culture (Tanaka, K., Ikegaki, N., and Ichihara, A. (1979) Biochem. Biophys. Res. Commun. 91, 102-107). The induced acidic protease was purified about 600-fold in 30% yield from rat liver by conventional chromatographic techniques. The purified enzyme appeared homogeneous by polyacrylamide gel electrophoresis in the presence or absence of sodium dodecyl sulfate and was a monomeric protein of Mr = 20,000. The enzyme appeared to be a glycoprotein because its induction was blocked by the addition of tunicamycin to cultures of hepatocytes and because the induced protease was absorbed on concanavalin A-Sepharose and eluted with methylglucoside. It seemed to be present in lysosomes and was fairly stable at various pH values and temperatures. It showed endopeptidase activity on various protein substrates, but scarcely hydrolyzed N-substituted derivatives of arginine. It did not hydrolyze esters, showed no aminopeptidase or carboxypeptidase activity, and did not inactivate glucose-6-phosphate dehydrogenase or aldolase. The enzyme appeared to be a thiol protease, since it was strongly inhibited by sulfhydryl-reactive compounds and N-( [N-(1-3-trans-carboxyoxiran-2-carbonyl)-L-leucyl]-agmatine and was not inhibited by reagents specific for carboxyl-, serine-, or metalloproteases. This induced protease could be separated from cathepsins B, D, and H by chromatography. The enzyme was similar to cathepsin L in chromatographic behavior, Mr and pI, but differed from the latter in stability and in its inability to inactivate some enzymes. These results suggest that it differs from any known proteases found previously in rat liver.
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PMID:Purification and characterization of hemoglobin-hydrolyzing acidic thiol protease induced by leupeptin in rat liver. 637 Oct 12

The nature of the association of the glycolytic enzyme, aldolase, with mature bovine spermatozoa was investigated in comparison with bovine muscle aldolase. Bovine muscle aldolase (BMA) was optimally solubilized by 0.1% deoxycholate and purified to homogeneity by ammonium sulfate fractionation, gel-filtration chromatography and phosphocellulose affinity chromatography. Bovine sperm aldolase (BSpA) was solubilized with optimal specific activity by 0.1% Triton X-100 and 50 mM sodium phosphate. Soluble BSpA represented 10% of the total aldolase activity in bovine spermatozoa. It could not be purified from other sperm components by standard procedures. The association of BSpA with sperm components involved noncovalent, ionic and hydrophobic interactions and did not involve disulfide bonds or covalent bonds. The stability of the BSpA association with intracellular substructure implies that very specific multiple-ligand bonding is involved. The Km for fructose-1-phosphate (1.7 X 10(-1) M) was higher and the activity with fructose-1,6-biphosphate relative to fructose-1-phosphate (Vmax FBP/Vmax F-1-P = 0.038) was much lower than for either liver or muscle aldolase. Kinetic analysis and subcellular associations indicated that sperm aldolase is different from other isozymes of aldolase.
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PMID:Association of bovine sperm aldolase with sperm subcellular components. 646 57

Properties of newly synthesized crosslinking reagents (ACM) and their applications to proteins are studied (ACM is the abbreviation for a series of photoactivable and heterobifunctional crosslinking thiol reagents, each of which has two reactive groups, maleimide and azide). These reagents bind specifically to the sulfhydryl residues of proteins in the first reaction step. Upon photoactivation, the azide group of the coumarin ring reacts with side or main chains of the proteins, and thus intra- or intermolecular crosslinking can be elicited. In addition, the coumarin moiety of the reagents becomes highly fluorescent after photolysis. Therefore, the crosslinking products can be detected by fluorometry with high sensitivity in the pattern of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Reaction of ACM with rabbit muscle aldolase led to extensive crosslinking between subunits of the enzyme and maximally 25% of the total subunits were found to be crosslinked to the dimer.
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PMID:New fluorogenic, photoactivable, heterobifunctional crosslinking thiol reagents. 648 17

Hemoglobin A1 (HbA1) levels were significantly higher in healthy alcohol drinkers (HbA1 = 7.50%, n = 11) than in normal non-drinkers (HbA1 = 6.62%, n = 13). Ethanol was not able to change HbA1 level when ethanol was added to human whole blood in vitro. Acetaldehyde (AcCHO), although, markedly increased it. Glucose utilization in erythrocytes was stimulated by AcCHO. While it was completely blocked by sodium fluoride in the presence of AcCHO in the incubation medium, but sodium fluoride did not affect the formation of HbA1. AcCHO formed HbA1 with human purified hemoglobin in vitro. The level of HbA1 formed by AcCHO was significantly low when purified human hemoglobin used as a substrate in comparison with the use of whole blood. AcCHO and dihydroxyacetone phosphate reacted in the presence of aldolase. The reacted product, 5-deoxy-D-xylulose-1-phosphate, increased HhA1 level of human purified hemoglobin. It is suggested, the high level of HbA1 in healthy drinkers was caused by AcCHO, the first metabolite of ethanol. AcCHO formed addicts with human hemoglobin directly, and there might be other mechanisms of HbA1 formation due to AcCHO, such as 5-deoxy-D-xylulose-1-phosphate, which is the reacted product of AcCHO.
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PMID:[Mechanisms of high hemoglobin A1 in alcohol drinkers]. 651 Aug 86

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 cytosol and chloroplast fructose-bisphosphate aldolases from spinach leaves were separated by ion-exchange chromatography on DEAE-cellulose, and were purified by subsequent affinity chromatography on phosphocellulose to apparent homogeneity as judged from polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The two aldolases had specific activities of 7.2 and 7.8 units mg protein-1. Molecular weight determinations by electrophoresis in sodium dodecyl sulfate gels and by sedimentation velocity centrifugation in sucrose gradients showed that the aldolases contained four subunits of Mr 38 000 and 35 000, respectively. Antibodies against the cytosol and chloroplast aldolase from spinach leaves were raised in a guinea pig and in a rabbit, respectively. In the Ouchterlony double-diffusion test, the two aldolases did not cross-react. A small degree of cross-reaction was observed by a test in which immune complexes were adsorbed to a solid-phase support (Staphylococcus aureus Cowan I cells) and nonbound enzyme activity was determined after centrifugation. These results imply major structural differences between the two spinach leaf aldolases. Only one major aldolase could be resolved on DEAE-cellulose from corn leaves. The aldolase was purified and had a specific activity of 6.4 units X mg protein-1. The corn leaf aldolase cross-reacted with the antiserum raised against the chloroplast enzyme from spinach leaves, but not with the other antiserum. Thus, the corn leaf aldolase could be identified as a chloroplast enzyme. Since aldolase activity is mostly restricted to the bundle sheath cells of corn leaf, it was concluded that it is compartmentalized in the chloroplasts of these cells but not in chloroplasts of the mesophyll cells.
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PMID:Purification, subunit structure and immunological comparison of fructose-bisphosphate aldolases from spinach and corn leaves. 661 52

Hereditary fructose intolerance (HFI) is a disorder of visceral carbohydrate metabolism which is transmitted as a recessive character of moderate to high gene prevalence. The condition is caused by enzymic deficiency of aldolase B and is associated with the synthesis of inactive enzyme protein. The molecular structure of aldolase B was examined in tissue samples from four adult patients who were the offspring of non-consanguineous unions. Titration of aldolase protein, by radioimmunoassay, showed that antibody recognition of the inactive enzyme was attenuated differently in two unrelated HFI patients. The existence of separate structural lesions was confirmed by protein blotting and immunodetection of enzyme subunits after sodium dodecyl sulphate/polyacrylamide electrophoresis. In one patient the subunit size was identical to wild type (Mr 38,000) and in the other, a single faint band (Mr 39,000) was identified. Radioimmunotitration studies, in two affected offspring of this latter patient by a proven HFI carrier, also revealed differences in antibody recognition. Segregation of different mutant alleles within this kindred demonstrates heterogeneity in HFI occurring at the same genetic locus. Variations in apparent immunoreactivity of aldolase B in HFI are thus related to overt modification of enzyme subunits and indicate that the disorder results principally from structural rather than regulatory mutations in the aldolase B gene.
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PMID:Allelic heterogeneity in adult hereditary fructose intolerance. Detection of structural mutations in the aldolase B molecule. 668 Jan 53

Highly purified glycosomes were isolated from Trypanosoma brucei bloodstream forms and cultured procyclic trypomastigotes. A comparison of the specific activities of glycosomal enzymes revealed that glycosomes from insect stages had decreased levels of hexokinase, phosphoglucose isomerase, phospho-fructokinase, fructose-bisphosphate aldolase, glyceraldehyde-phosphate dehydrogenase and phosphoglycerate kinase, but contained increased levels of adenylate kinase, malate dehydrogenase and phosphoenolpyruvate carboxykinase. Glycosomes from bloodstream forms were almost totally devoid of the latter two activities. Comparison of the two types of glycosomes by sodium dodecylsulphate-polyacrylamide gel electrophoresis revealed that bloodstream form glycosomes contained 3 prominent polypeptides (64, 46 and 40 kDa) which were hardly detectable in insect stage glycosomes, whereas the latter contained 3 insect stage specific bands with molecular weight of 34 000, 61 000 and 77 000 and 4 additional bands with molecular weights between 94 000 and 110 000. Both types of glycosome contained the phospholipids phosphatidylcholine and phosphatidylethanolamine. Insect stage glycosomes contained in addition also phosphatidylinositol and some phosphatidylserine.
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PMID:A comparison of the glycosomes (microbodies) isolated from Trypanosoma brucei bloodstream form and cultured procyclic trypomastigotes. 674 87

Hereditary fructose intolerance is due to a deficiency of liver aldolase (aldolase B). Little is known about its molecular mechanisms. We have tried to demonstrate the presence of the molecule and have explored the possibility of genetic heterogeneity. Liver samples from fifteen cases of hereditary fructose intolerance due to aldolase B deficiency were studied by various electrophoretic techniques. After electrophoresis on polyacrylamide gels, proteins were electrophoretically transferred on to nitrocellulose filters. They were treated with specific antialdolase B antibodies, and then with radioiodinated protein A, followed by autoradiography. Investigations included: (a) sodium dodecyl sulphate electrophoresis, in order to detect the presence of immunologically reactive molecules and to estimate the subunit size; (b) attempts to discover charge anomalies of the native molecule and of its subunits, by the use of: Isoelectric focusing of the native enzyme. Isoelectric focusing and non-equilibrium pH gradient electrophoresis (NEPHGE) after dissociation in urea. The major results were the following: (1) In all cases a cross-reacting material was found, with a molecular subunit size of 38000, indistinguishable from that of controls. (2) Evidence for molecular heterogeneity of the disease was provided by two types of data: amount of apparent immunologically reactive protein, which varied from less than 3% to 100% of that of controls; and charge data, aldolase B from seven patients showing an increased negative charge and from one patient a normal charge.
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PMID:Molecular studies of liver aldolase B in hereditary fructose intolerance using blotting and immunological techniques. 676 Jul 89


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