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 interactions of aldolase with regulatory proteins of rabbit skeletal muscle were investigated by moving-boundary electrophoresis. A salt-dependent interaction of troponin, tropomyosin and the tropomyosin-troponin complex with aldolase was detected, the tropomyosin-troponin complex displaying a greater affinity for the enzyme than did either regulatory protein alone. The results indicate that aldolase possesses multiple binding sites (three or more) for these muscle proteins. Quantitative studies of the binding of aldolase to actin-containing filaments showed the interaction to be influenced markedly by the presence of these muscle regulatory proteins on the filaments. In imidazole/HCl buffer, I 0.088, pH 6.8, aldolase binds to F-actin with an affinity constant of 2 x 10(5) M-1 and a stoicheiometry of one tetrameric aldolase molecule per 14 monomeric actin units. Use of F-actin-tropomyosin as adsorbent results in a doubling of the stoicheiometry without significant change in the intrinsic association constant. With F-actin-tropomyosin-troponin a lower binding constant (6 x 10(4) M-1) but even greater stoicheiometry (4:14 actin units) are observed. The presence of Ca2+ (0.1 mM) decreases this stoicheiometry to 3:14 without affecting significantly the magnitude of the intrinsic binding constant.
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PMID:Binding of aldolase to actin-containing filaments. Evidence of interaction with the regulatory proteins of skeletal muscle. 689 70

Electron micrographs of the paracrystals formed when fructose bisphosphate aldolase (EC 4.1.2.13) is added to actin-containing filaments were analysed by computer methods so that ultrastructural changes could be correlated with the various stoicheiometries of binding determined in the preceding paper [Walsh, Winzor, Clarke, Masters & Morton (1980) Biochem. J. 186, 89-98]. Paracrystals formed with aldolase and either F-actin or F-actin-tropomyosin have a single light transverse band every 38 nm, which is due to aldolase molecules cross-linking the filaments. In contrast, the paracrystals formed between aldolase and F-actin-tropomyosin-troponin filaments show two transverse bands every 38 nm: a major band, interpreted as aldolase binding to troponin, and a minor band, interpreted as aldolase cross-linking the filaments. The intensity of the minor band varies with Ca2+ concentration, being greatest when the Ca2+ concentration is low. A model for the different paracrystal structures which relates the various patterns and binding stoicheiometries to structural changes in the actin-containing filaments is proposed.
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PMID:Interaction of aldolase with actin-containing filaments. Structural studies. 689 71

Purified glycolytic enzymes were individually chromatographed through columns of Sepharose 4B containing a covalently bound F-actin-tropomyosin complex. Five of these enzymes, aldolase, glyceraldehyde-phosphate dehydrogenase, lactate dehydrogenase, pyruvate kinase, and phosphoglycerate kinase were able to interact with the complex. Glucosephosphate isomerase, triosephosphate isomerase, phosphoglycerate phosphomutase, and enolase did not bind to the F-actin-tropomyosin matrix. One nonbinding enzyme, phosphoglycerate phosphomutase, was observed to interact with F-actin-tropomyosin if the column was preloaded with lactate dehydrogenase. Since at least four other glycolytic enzymes did not associate with actin directly, it is suggested that if a glycolytic enzyme complex exists, these nonadsorbing enzymes must interact with one or more of the enzymes which do bind to actin.
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PMID:Interaction of muscle glycolytic enzymes with thin filament proteins. 729 40

Previously reported results of equilibrium-partition experiments on the interaction of aldolase with actin-containing filaments [Walsh, Winzor, Clarke, Masters & Morton (1980) Biochem. J. 186, 89-98] have been subjected to a more rigorous theoretical analysis involving consideration of the consequences of cross-linking interactions between enzyme and filament. The experimental results obtained with F-actin-tropomyosin are best described by a model with one binding site per heptameric repeat unit of filament and a value of 39000 M-1 for the site binding constant, k. Similar analyses of the influence of Ca2+ on aldolase binding to F-actin--tropomyosin--troponin substantiate the existence of two equivalent binding sites (k = 14900 M-1) for the enzyme on each repeat unit of the thin filament. The Ca2+-sensitivity of this interaction reflects either a decrease in the strength of aldolase binding to these two sites (k = 8200 M-1) or the elimination of one site.
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PMID:Binding of aldolase to actin-containing filaments. Quantitative reappraisal of the interactions. 730 56

The influence of various actin-binding proteins and drugs on the fluorescence emission of rabbit muscle actin labelled with the fluorescent probe acrylodan (6-acryloyl-2-dimethylaminonaphthalene) at Cys-374, the penultimate amino acid residue of the actin amino acid sequence, was studied. Addition of myosin, tropomyosin or phalloidin, agents known to bind only to filamentous F-actin, did not change the emission energy or the integrated intensity of the fluorescence spectrum. The presence of heavy meromyosin or of the glycolytic enzyme aldolase led to a small (approx. 2%) increase in the integrated intensity, and in the energy of the emitted fluorescence. The interaction of 6-propionyl-2-(NN-dimethyl)aminonaphthalene (PRODAN)-F-actin with pancreatic DNAase I and with a filament-severing 19 kDa protein from pig brain resulted in the gradual reduction of the integrated intensity of the emission and a red shift of the emission energy, suggestive of a disintegration of the actin filament structure. Profilin caused a < 10% change in the emission energy. Cytochalasin D reduced the integrated intensity of PRODAN-F-actin and red-shifted the emission energy, while cytochalasin B was without influence. Pancreatic DNAase I did not change the fluorescence emission of PRODAN-G-actin, suggesting that binding of this enzyme does not alter the environment of the probe. When the 19 kDa protein bound to PRODAN-G-actin, however, the integrated intensity was reduced and the emission energy was lowered. This effect was exploited to estimate the binding constant for the interaction between the 19 kDa protein and PRODAN-G-actin. The Kd was found to be about 0.25 microM.
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PMID:The interaction of 6-propionyl-2-(NN-dimethyl)aminonaphthalene (PRODAN)-labelled actin with actin-binding proteins and drugs. 845 29

Formation of mixed disulfides between glutathione and the cysteines of some proteins (glutathionylation) has been suggested as a mechanism through which protein functions can be regulated by the redox status. The aim of this study was to identify the proteins of T cell blasts that undergo glutathionylation under oxidative stress. To this purpose, we radiolabeled cellular glutathione with (35)S, exposed T cells to oxidants (diamide or hydrogen peroxide), and performed nonreducing, two-dimensional electrophoresis followed by detection of labeled proteins by phosphorimaging and their identification by mass spectrometry techniques. We detected several proteins previously not recognized to be glutathionylated, including cytoskeletal proteins (vimentin, myosin, tropomyosin, cofilin, profilin, and the already known actin), enzymes (enolase, aldolase, 6-phosphogluconolactonase, adenylate kinase, ubiquitin-conjugating enzyme, phosphoglycerate kinase, triosephosphate isomerase, and pyrophosphatase), redox enzymes (peroxiredoxin 1, protein disulfide isomerase, and cytochrome c oxidase), cyclophilin, stress proteins (HSP70 and HSP60), nucleophosmin, transgelin, galectin, and fatty acid binding protein. Based on the presence of several protein isoforms in control cells, we suggest that enolase and cyclophilin are heavily glutathionylated under basal conditions. We studied the effect of glutathionylation on some of the enzymes identified in the present study and found that some of them (enolase and 6-phosphogluconolactonase) are inhibited by glutathionylation, whereas the enzymatic activity of cyclophilin (peptidylprolyl isomerase) is not. These findings suggest that protein glutathionylation might be a common mechanism for the global regulation of protein functions.
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PMID:Identification by redox proteomics of glutathionylated proteins in oxidatively stressed human T lymphocytes. 1190 14

Muscle-type LDH (LDH-m4) activity is critical for efficient anaerobic glycolysis. The results here show that rabbit LDH-M4 is inhibited by concentrations of ascorbate normally found in tissues. Aldolase and muscle G-actin were found to protect and to reverse inhibitions of LDH-m4 by ascorbate. G-actins showed some species specificity. Myosin, tropomyosin and troponin from rabbit muscle and muscle proteins from other animal sources had no affect on the inhibitions by ascorbate. The substrate inhibition of LDH-m4 by pyruvate is partially relieved by the presence of aldolase and lowers the Km without affecting the Vm. G-actin under similar conditions has no affect. It is believed that these studies reflect some of the resting properties of glycolytic enzymes that bind and unbind to contractile elements. It is proposed that ascorbate facilitates the storage of glycogen in muscle at rest by inhibiting glycolysis.
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PMID:Aldolase and actin protect rabbit muscle lactate dehydrogenase from ascorbate inhibition. 1520 99

Hepatocellular carcinoma (HCC) is a major cause of death in Japan. It has been suggested that hepatitis C virus (HCV) plays an important role in hepatocarcinogenesis, because of high incidence among the patients. To understand the mechanism of hepatocarcinogenesis after HCV infection, we performed a comparative study on the protein profiles between tumorous and nontumorous specimens from the patients infected with HCV by means of two-dimensional electrophoresis. Eleven spots were decreased in HCC tissues from over 50% of the patients. Eight proteins out of 11 spots were identified using peptide mass fingerprinting with matrix-assisted laser desorption/ionization-time of flight-mass spectrometry. These proteins were liver type aldolase, tropomyosin beta-chain, ketohexokinase, enoyl-CoA hydratase, albumin, smoothelin, ferritin light chain, and arginase 1. The intensity of enoyl-CoA hydratase, tropomyosin beta-chain, ketohexokinase, liver type aldolase, and arginase 1 was significantly different (p < 0.05). The decrease of 8 proteins was characteristic in HCC. We will discuss the implication of these proteins for the loss of function of hepatocytes and for the possibility of carcinogenesis of HCV-related HCC.
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PMID:Proteomic profiling of proteins decreased in hepatocellular carcinoma from patients infected with hepatitis C virus. 1522 72

Decline in olfactory ability has been associated with aging as well as neurodegenerative disorders. The aim of this study was to gain fundamental insight into molecular events associated with the aging olfactory system. We report a comparative proteomic analysis of the olfactory epithelium (OE) and olfactory bulb (OB) of old (80-week old) and young (6-week old) mice with further analysis of age-related differences in differentially expressed proteins at the mRNA level using real-time RT-PCR. Nine proteins in the OE and 20 in the OB were differentially expressed in old and young mice; of these, aldolase 1, peptidyl prolyl isomerase A, mitochondrial aconitase 2, mitochondrial aldehyde dehydrogenase 2 and albumin 1 were identified in the OE; and ATP synthase isoform 1, enolase 1, ferritin heavy chain, malate dehydrogenase 1, tropomyosin alpha 3 chain and dynamin 1 were identified in the OB. At the transcriptional level, aconitase 2 in the OE and ferritin heavy chain 1 in the OB were differentially expressed with aging, in concordance with the proteomic data. Our results demonstrate an altered proteomic profile of the aged murine olfactory system. The identified proteins fall into three broadly defined functional categories: (i) metabolism, (ii) transport/motility and (iii) stress response. Our transcriptional analysis provides insight into possible mechanisms by which protein expression may be regulated in the OE and OB. The results are discussed in relation to the decrement in olfactory sensitivity with aging.
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PMID:Proteomic identification of differentially expressed proteins in the aging murine olfactory system and transcriptional analysis of the associated genes. 1599 89

In the present study, we describe the investigation of Echinostoma friedi excretory/secretory products using a proteomic approach combined with the use of heterologous antibodies. We have identified 18 protein spots corresponding to ten proteins, including cytoskeletal proteins like actin, tropomyosin, and paramyosin; glycolytic enzymes like enolase, glyceraldehyde 3P dehydrogenase, and aldolase; detoxifying enzymes like GSTs; and stress proteins like heat shock protein (Hsp) 70. Among these proteins, both actin and, to a lesser extent, Hsp70, exhibited differential expression patterns between chronic and acute infections in the Echinostoma-rodent model, suggesting that these proteins may play a role in the survival within the host.
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PMID:Identification of proteins in excretory/secretory extracts of Echinostoma friedi (Trematoda) from chronic and acute infections. 1657 68


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