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 binding isotherms of native bovine serum albumin with cationic detergents, such as octyl, decyl, dodecyl and tetradecylpyridinium bromides were determined at pH 6.8 and 3.4 at 25 degrees C. The isotherms for dodecyl and tetradecylpyridinium bromides were also determined at 3 degrees C. The average number of detergent cations bound increased with increasing hydrocarbon chain length. At low detergent concentration the binding of all alkylpyridinium bromides was smaller at pH 3.4 than at pH 6.8. Dodecylpyridinium bromide was bound to native beta-lactoglobulin, aldolase, ovalbumin, haemoglobin, myoglobin, lysozyme, trypsin and ribonuclease at pH 6.8. No binding occurred to alpha-chymotrypsin and chymotrypsinogen. The free enthalpy change, --delta G degrees, calculated from intrinsic association constants K was determined.
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PMID:Protein-cationic detergent interaction. Equilibrium dialysis study of the interaction of bovine serum albumin and other proteins with alkylpyridinium bromide. 49 43

Adenylate cyclase from purified beef thyroid membranes has been solubilized by the use of Triton N-101 after preactivation with guanosine 5'-(beta, gamma-imido)-triphosphate. The soluble activity passed a 0.22- micron filter, was not sedimented at 100,000 X g for 2 h, and behaved like aldolase in sucrose density gradients and on Sepharose 6B. From comparison of the sedimentation in D2O and H2O the partial specific volume was found to be like that of globular proteins (0.75 +/- 0.006), hence little detergent appeared to be bound to the enzyme. The sedimentation coefficient was 7.4 +/- 0.15, the Stokes radius 45 A, and the molecular weight 159,000. Prestimulation by thyrotropin did not survive solubilization. The stimulation produced by guanosine 5'-(beta, gamma-imido)triphosphate persisted as did the more active state resulting from pretreatment with both this nucleotide plus thyrotropin. Thyrotropin did not stimulate the solubilized enzyme. The Km for ATP, thermal stability, and inhibition by Ca2+ were identical for the membrane-bound and soluble enzyme, while the pH optimum was increased 0.5 unit in the latter. Polyanions and phenothiazines inhibited both preparations equally, whereas only membranes responded to stimulation by polylysine and ribonuclease.
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PMID:Soluble adenylate cyclase from thyroid membranes. 67 Jan 96

The hydrophobic nature of proteins is characterized by a degree of 2-p-toluidinonaphthalene-6-sulphonate (TNS) affinity to them and is pronounced quantitatively in the semi-saturated (C1/2) concentrations. This index correlates directly with the position of TNS emission maximum after the binding with proteins and reversely with the yield of fluorescence. The preparations of phosphofructokinase, lactate dehydrogenase, xantinoxidase, glyceratekinase, lysozyme, RNase during the long (1-2 h) contact with TNS change the values C1/2, that evidences for interaction with the hydrophobic indicator of new structures of protein molecule or for a change in the nature of its linkage itself. An attempt is made to characterize the accessible for TNS hydrophobic nature of individual proteins by a coefficient of molar hydrophobic nature which unites three mentioned characteristics. Serum albumin, insulin, glucogon, alpha chemotrypsin, DNase are most hydrophobic, pyruvate kinase, aldolase, urease, RNase--least hydrophobic, Glycerate kinase, pyruvate decarboxylase, phosphofructokinase, lactate dehydrogenase, alcohol dehydrogenase, xanthinoxidase, trypsin, lysozyme are in intermediate position.
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PMID:[Comparative characteristics of hydrophobic nature of certain proteins by their interaction with 2-p-toluidinonaphthalene-6-sulfonates]. 120 4

When E. coli carrying multicopy plasmids for fructose-1,6-P2 aldolase or phosphoglycerate kinase was grown in the presence of 32Pi, there was label at the position of cognate high level polypeptide after SDS-PAGE. As tested for aldolase, the label was resistant to acetone, RNase, and hot TCA treatments, and was also observed by immunoprecipitation, which was competed for by purified aldolase. Incorporation of label also occurred in the presence of chloramphenicol. Immunoprecipitation revealed apparent aldolase labeling in the wild type strain as well.
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PMID:Phosphate modification of fructose-1,6-bisphosphate aldolase in Escherichia coli. 328 66

Protein synthesis, normally a light-dependent process in isolated mature chloroplasts of Euglena gracilis var. bacillaris will take place in darkness if ATP and Mg2+ (ATP/Mg) are supplied. Either 5 or 10 mM ATP plus 15 mM MgCl2 are optimal and rates equal to those in the light can be obtained. Since ATP and Mg2+ are not stoichiometrically related, and since the optimal Mg2+ concentration is similar to that which stabilizes chloroplast ribosomes in vitro, it is suggested that the chloroplast is freely permeable to Mg2+ under these conditions. Protein synthesis under these conditions is not inhibited appreciably by DCMU, FCCP, cycloheximide, or by the addition of ribonuclease, but is highly sensitive to chloramphenicol. Carbon dioxide fixation is also a light-dependent process in isolated mature chloroplasts from Euglena, but addition of ATP (5 mM) and fructose bisphosphate (5 mM) plus aldolase (1.0 unit/ml) (fructose-1,6-bisphosphate/aldolase) yields CO2 fixation rates in darkness that are 43% of those normally obtained in the light. Mg2+ higher than 1.0 mM (e.g., 16 mM) is somewhat inhibitory. Chlorophyll synthesis from 5-aminolevulinate in 36 h developing chloroplasts from Euglena is also light-dependent, but addition of ATP/Mg and fructose-1,6-bis-phosphate/aldolase in darkness brings about the accumulation of a compound having the same RF on chromatography as protochlorophyllide from Barley; a subsequent brief illumination of the chloroplasts converts this compound to a compound with the RF of chlorophyll. Thus Euglena chloroplasts supplied with appropriate additions can carry out protein synthesis, carbon dioxide fixation and most of chlorophyll synthesis in darkness. This versatility is appropriate in photosynthetic organelles isolated from photo-organotrophic cells.
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PMID:Synthetic abilities of Euglena chloroplasts in darkness. 392 91

Experiments were run on three groups of healthy guinea pigs. One group was given ethionamide, kanamycin and PASA another was given ethionamide, kanamycin and pyrazinamide while the third served as a control. These studies permitted to establish that the above drugs affect the activity of enzymes involved in the metabolism of carbohydrates and nucleic acids. Activity of glucose-6-phosphatase and aldolase significantly decreased in liver, brain and lung tissue. At the same time, activity of deoxyribonuclease and ribonuclease in the tissues concerned sharply increased. Changes in activity of phosphohexose isomerase, lactate dehydrogenase and aminotransferases in these tissues was statistically insignificant.
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PMID:[Effect of various combinations of antibacterial drugs on enzyme activity in guinea pig tissues]. 531 14

The availability of very high magnetic fields of up to 170,000 gauss made it worthwhile to pursue the search for a critical change in the rate of four enzyme substrate reactions. The four enzymes were ribonuclease, polyphenol oxidase, peroxidase, and aldolase. The experiments showed that, to within +/-3%, no detectable change was observable in the rate of reaction of any of the systems for periods of exposure to the magnetic field of up to 20 min.
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PMID:Enzyme-substrate reactions in very high magnetic fields. I. 604 70

Models describing the interaction of a small molecule with a protein are typically couched in terms of the stoichiometry, cooperativity, and binding free-energy change. These parameters are readily available from equilibrium dialysis experiments (or appropriate variations). With the recent advent of extremely sensitive calorimeters, it is possible to obtain thermal data for the binding reaction and, thus, the entire set of thermodynamic parameters, delta G', delta H', delta S', delta C', become readily available. This review is limited to the binding of nucleotides and nucleotide analogs to proteins for which complete thermal data are available. While the majority of such systems have been characterized by calorimetry, we have not excluded, per se, van't Hoff enthalpy determinations. The systems we have considered include, but are not limited to, thymidylate synthetase, phosphorylase, several dehydrogenases, aldolase, glutamine synthetase, hemoglobin, asparate transcarbamylase, and ribonuclease. A variety of forces contribute to the total free-energy change upon ligand binding. These forces include ionic, van der Waals, hydrogen bond, and hydrophobic. In several cases, properly designed experiments have allowed a partial resolution of the individual contributions of these various forces. Variation of easily accessible conditions such as temperature, pH, ionic strength, or solvent third component produce changes in the set of thermodynamic parameters which lead to the resolution of the forces. The generality of heat effects makes this method very useful for studying the involvement of protons in binding reactions. The variation in the magnitude and direction (release or uptake) of the proton flux is readily studied by determining the apparent heat of reaction at constant pH, ionic strength, and temperature in two or more buffers of differing heat of ionization. This application has been exploited in several cases and is examined in great detail. An overview of the results in these systems to date suggests that several trends observed in the thermodynamic parameters need to be confirmed by further experimentation and, if they hold, an appropriate theoretical basis must be developed to aid in their interpretation.
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PMID:The thermodynamics of nucleotide binding to proteins. 610 94

We have used low shear falling ball viscometry to measure the effects of actin purity, solution conditions, and cross-linking macromolecules on the formation of actin filament networks. Removal of minor contaminants from conventional muscle actin (Spudich, J. A., and Watt, S. (1971) J. Biol. Chem. 246, 4866-4871) by gel filtration (MacLean-Fletcher, S. and Pollard, T.D. (1980c) Biochem. Biophys. Res. Commun. 96, 18-27), greatly promotes the interaction of the filaments. Purified actin filaments form a gel (apparent viscosity greater than 12,000 cp) at approximately 2 mg/ml whereas approximately 12 mg/ml of conventional actin filaments have a viscosity of less than 400 cp. The apparent viscosity of the filaments depends on pH and the concentration of monovalent and divalent cations. The viscosity of purified action filaments is more sensitive to such variables when compared to that of conventional actin filaments. Together these experiments suggest that actin filament self-associations contribute to the stabilization of actin gels. A number of basic macromolecules, including aldolase, histones, lysozyme, polylysine, and RNase A can bind to and crosslink conventional actin filaments to form a gel. Since it is unlikely that all of these molecules are bound to actin in vivo, experimental approaches in addition to viscometry and sedimentation must be applied to prove that a given protein functions as an actin cross-linking protein in the cell.
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PMID:Cross-linking of actin filament networks by self-association and actin-binding macromolecules. 709 56

Ribonuclease A was introduced into the cytoplasm of IMR-90 human diploid fibroblasts by red cell-mediated microinjection. Early passage fibroblasts degraded ribonuclease A with a half-life of approximately 90 h in the presence of 10% fetal calf serum and enhanced the degradative rate 1.6-fold upon serum withdrawal. Senescent cells degraded ribonuclease A more slowly with half-lives ranging between 125 and 250 h and had diminished capacities to enhance the catabolism of this protein during serum starvation. Decreased protein degradation in senescent cells was also evident for microinjected RNase S-protein, RNase B, aldolase, lysozyme, and the synthetic copolymer polyglutamate: tyrosine:alanine (1:1:1). These alterations in the mechanisms and regulation of intracellular protein degradation may contribute to several biochemical abnormalities characteristic of aging cells and organisms.
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PMID:Altered degradation of proteins microinjected into senescent human fibroblasts. 717 58


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