Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:APRD00631 (Gel)
 14,881 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two forms of adenosine deaminase (adenosine aminohydrolase, EC 3.5.4.4), differing in molecular size, have been purified and obtained in homogeneous form from rabbit intestine. The purification procedures involved extraction with acetate buffer, pH 5.5, precipitation and fractional reextraction with (NH4)2SO4, ion-exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-75 and Sephadex G-200. Gel filtrations analysis gave molecular weight estimates of 265 000 and 32 000 for the large and small deaminases respectively. The two enzymes forms had similar pH optima and pH stability ranges.
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PMID:Purification of multiple forms of adenosine deaminase from rabbit intestine. 0 39

The major portion of glutamine synthetase activity in root nodules of soya-bean plants is associated with the cytosol rather than with Rhizobium japonicum bacteroids. Glutamine synthetase accounts for about 2% of the total soluble protein in nodule cytosol. Glutamine synthetase from nodule cytosol has been purified by a procedure involving fractionation with protamine sulphate, ammonium sulphate and polypropylene glycol, chromatography on DEAE-Bio-Gel A and Bio-Gel A-5m and affinity chromatography on glutamate-agarose columns. The purified preparation appeared to be homogeneous in the analytical ultracentrifuge. From sedimentation-equilibrium experiments a mol. wt. of about 376000 was determined for the native enzyme and 47300 for the enzyme in guanidinium chloride. From these data and measurements of electron micrographs, we have concluded that glutamine synthetase from nodule cytosol consists of eight subunits arranged in two sets of planar tetramers which form a cubical configuration with dimensions of about 10 nm (100 A) across each side. Glutamine synthetase from nodule cytosol has a higher glycine and proline content and a lower content of phenylalanine than the glutamine synthetase that has been prepared from pea seed. The cytosol enzyme contains four half-cystine molecules per subunit, which is in contrast with two reported for the enzyme from pea seed. Enzyme activity is striking influenced by the relative proportion of Mg2+ and Mn2+ in the assay medium. Activity is inhibited by feedback inhibitors and is influenced by energy charge.
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PMID:The purification and properties of the glutamine synthetase from the cytosol of Soya-bean root nodules. 0 35

1. A cyclic 3',5'-AMP-independent protein kinase (ATP : protein phosphotransferase, EC 2.7.1.37) from rat liver cytosol was partially purified and characterized. Purification by (NH4)2SO4 precipitation, DEAE-cellulose, Bio Gel A-0.5 m and cellulose phosphate chromatography increased the specific activity about 700-fold. 2. An endogenous protein substrate was closely associated with the protein kinase and was not separable from this enzyme up to the cellulose phosphate stage. After phosphorylation, chromatography with Bio Gel A-0.5 m partially separated this endogenous phosphoprotein from the enzyme activity; this dissociation had no apparent effect on kinase activity with casein or phosvitin as substrates, or on the apparent molecular weight of the enzyme (approx. 158,000). 3. This protein kinase with casein, phosvitin, or the endogenous substrate was totally insensitive to the thiol reagents, p-hydroxymercuribenzoate, 5,5'-dithiobis(2-nitrobenzoic acid), iodoacetamide, and N-ethylmaleimide. The enzyme was also unaffected by cyclic 3',5'-AMP, heat-stable protein kinase inhibitor, and the regulatory subunit of a cyclic 3',5'-AMP-dependent protein kinase.
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PMID:Partial purification and properties of a cyclic 3',5'-AMP-independent protein kinase from rat liver. 1 21

Galactokinase (EC 2.7.1.6; ATP:D-galactose-1-phosphotransferase) was purified to homogeneity with a 50% yield from cells of Saccharomyces cerevisiae which were fully induced for the production of the galactose metabolizing enzymes. The purification was accomplished by:(a) ammonium sulfate fractionation, (b) streptomycin sulfate precipitation. (c) DEAE-cellulose chromatography, (d) hydroxylapatite chromatography, and finally (e) Bio-Gel A-0.5 m gel filtration. The resulting preparation of galactokinase was judged to be at least 95% pure by the following criteria: (a) sodium dodecyl sulfate-polyacrylamide gel electrophoresis, (b) ultracentrifuge analysis, (c) nondissociating polyacrylamide gel electrophoresis, and (d) Bio-Gel A-0.5 m gel filtration. The purified enzyme preparation was used to determine the Km values for the two substrates, galactose and ATP, which were found to be 0.60 and 0.15 mM, respectively. Vmax was also determined and found to be 3.35 mmol/h/mg. This corresponds to a turnover rate of 3350 molecules of galactose phosphorylated/min/enzyme molecule. The effect of pH on the galactokinase-catalyzed phosphorylation of galactose was determined; the results showed the pH optimum of the reaction to be in the range of pH 8.0 to 9.0. The enzyme is highly specific for galactose since galactokinase did not appear to phosphorylate any of the other sugars tested at a rate greater than 0.5% of the rate of galactose phosphorylation. Amino acid analysis was performed on the enzyme preparation and the results were used to calculate the partial specific volume (v) of 0.736. The NH2-terminal sequence was determined for the first 3 residues. The molecular weight and subunit composition were determined by ultracentrifugation and polyacrylamide gel electrophoresis under dissociating and nondissociating conditions. The data obtained indicated that galactokinase is a monomeric protein of molecular weight 58,000.
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PMID:Purification and properties of galactokinase from Saccharomyces cerevisiae. 1 44

An alkaline aminopeptidase was isolated from the culture medium of Penicillium roqueforti. The enzyme was purified by ammonium sulfate precipitation, filtration on Bio-Gel P-100, chromatography on D.E.A.E.-cellulose and hydroxylapatite, filtration on Bio-Gel P-150 and electrofusing. The purified preparation was homogeneous on polyacrylamide gel electrophoresis at pH 8.5. The molecular weight of the enzyme was estimated to be about 35,000 daltons. The isoelectric point is 4.5. The optimum pH for L-leucine-p-nitroanilide hydrolysis is 8.0. At 35 degrees C the enzyme is stable between pH 6.0 and 7.0. Ethylenediamine tetraacetic acid and a sulfhydryl reagent (p-hydroxymercuribenzoate) inhibit the activity, but the enzyme is insensitive to diisopropylfluorophosphate. Hydrolysis of synthetic peptides shows that the enzyme releases apolar amino acids. Dipeptides are poorly hydrolyzed and Gly in penultimate or N-terminal position causes poor activity. The enzyme is able to cleave the N-terminal Arg-Pro bond of bradykinin.
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PMID:The proteolytic system of Penicillium roqueforti. V. -- Purification and properties of an alkaline aminopeptidase. 2 80

A permeability factor was extracted in a latent form from guinea pig skin and separated by ammonium sulfate fractionation into the pseudoglobulin fraction (30--50% saturation). The activation of the latent form of the permeability factor seemed to be caused in the desalting step by gel filtration with Sephadex G-50. The factor was partially purified by streptomycin treatment and column chromatography using hydroxyapatite, diethylaminoethyl cellulose and Sephadex G-75, in this order. Gel filtration showed that its molecular weight was approx. 35000. Its permeability activity was heat stable at 61 degrees C for 60 min at neutral pH, resistant at pH 5--10 and at ionic strengths from deionized water to 1 M NaCl at 4 degrees C. Its activity was transient and suppressed by guinea pig serum, but insensitive to an anti-histamic agent (triprolidine). Furthermore, its permeability activity was inhibited by diisopropylfluorophosphate, soybean trypsin inhibitor and leupeptin, and completely adsorbed by soybean trypsin inhibitor affinity column. These findings suggested that the permeability factor was a serine-type protease.
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PMID:A protease-like permeability factor in the guinea pig skin. 1. Partial purification and characterization. 2 92

Renin-containing granules isolated by isopycnic zonal centrifugation were partially characterized biochemically. Extracts of the granules were found to have a dual pH optimum at 5.5-6.0 and 7.0-7.5 and possess linear time-dependence of product formation when reacted with homologous renin substrate. Extracts also possessed a first order reaction constant of 0.713 X 10(-2). Treatment of the extracts with ammonium sulfate increased the velocity of the renin/renin substrate reaction though it continued to be linear with respect to time. This partially purified renin preparation was found to have a Km=3.9 X 10(3) ng/ml. Gel filtration of this preparation of renin demonstrated the presence of an active protein with renin activity and a molecular weight of 59,000 daltons in addition to an inactive protein of molecular weight 13, 750 daltons which may be a potential inhibitor of the renin/renin substrate reaction. The former protein or "big renin" may be the storage form or porhormone state of renin within the renin-containing granules of the juxtaglomerular cells.
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PMID:Studies on the characterization of isolated renin-containing granules: the storage form of renin. 2 65

1. Three forms of glucoamylase [EC 3.2.1.3] were simultaneously purified from a Rhizopus species by (NH4)2SO4 fractionation and successive chromatographies on Sephadex G-75, DEAE-Sephadex, and CM-Sephadex, and were finally separated from each other by means of recycling chromatography on Bio-Gel P-150. The purification achieved was 3--4 fold from crude extract with respect to each glucoamylase; the yields of the three glucoamylases, designated as Gluc1, Gluc2, and Gluc3 in order of content, were 39, 7, and 0.4%, respectively. All the purified enzymes were homogeneous in polyacrylamide gel electrophoresis, isoelectric focusing, and ultracentrifugation. 2. The three glucoamylases were glycoproteins differing in both amino acid composition and carbohydrate content, but showed a common antigenicity in immunodiffusion. The molecular weights of Gluc1, Gluc2, and Gluc3 were estimated to be 74,000, 58,600, and 61,400, respectively, by sedimentation equilibrium and these values were verified by SDS-polyacrylamide gel electrophoresis. The specific activities of the three enzymes toward starch were in the opposite order to their molecular weights. 3. The three glucoamylases had the same broad pH optima in the range pH 4.5--5.0 and shared a common susceptibility to inactivation by heat, extreme pH, and such divalent cations as Hg2+, Pb2+, and Mn2+, indicating close similarity in enzymatic properties.
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PMID:Purification and some properties of three forms of glucoamylase from a Rhizopus species. 3 72

A protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) which catalyzes the phosphorylation of troponin T, phosvitin and casein has been purified over 2000 fold from rabbit skeletal muscle. The partial purification of this new enzyme, designated troponin T kinase, involves precipitation of contaminating proteins at pH 6.1, fractionation of the supernatant with (NH4)2SO4 and successive column chromatographies on DEAE-cellulose, hydroxyapatite and Sepharose 6B. The chromatographic patterns on DEAE-cellulose and hydroxyapatite columns show two peaks of troponin T kinase activity. Gel filtration experiments indicate the existence of multiple, possibly aggregated, forms of the enzyme. The purified enzyme does not catalyze the phosphorylation of phosphorylase b, troponin I, troponin C, tropomyosin, protamine, or myosin light chain 2 nor does it catalyze the interconversion of glycogen synthase I into the D form. Troponin T kinase is not affected by the addition of cyclic nucleotides or AMP to the reaction mixture. Divalent cations (other than Mg2+, required for the reaction) do not stimulate the enzyme, and several are inhibitory. Other characteristics of the reaction catalyzed by troponin T kinase, such as Km values for ATP and substrate proteins, pH optima, effect of the concentration of Mg2+, substitution of ATP for GTP have also been studied.
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PMID:Purification and properties of troponin T kinase from rabbit skeletal muscle. 3 14

We used a modification of the TSH radioreceptor assay to detect TSH-binding inhibition (TBI) activity in serum and serum fractions from normal subjects and patients with Graves' disease. TBI activity is present in normal IgG prepared by DEAE-Sephadex chromatography and in normal globulins prepared by precipitation at 1.6 M ammonium sulfate. Other normal serum proteins also had TBI activity when large concentrations were tested. Gel filtration chromatography and powder block electrophoresis were used to prepare fractions of normal and Graves' disease sera. In these fractions from normal serum. TBI activity was found in both gamma-globulin and alpha-globulin-albumin fractions electrophoretically and in both 7S and 4S peaks from gel filtration. TBI activity from Graves' disease patients' sera was similarly distributed, but relatively more TBI accompanied the electrophoretic gamma-globulins. Sepharose Protein-A and anti-IgG were used as immunoabsorbents to isolate and purify IgG from normal and Graves' disease sera. TBI activity in IgG was proportional to the IgG concentration, indicating that the TBI which migrates as a gamma-globulin electrophoretically is an IgG and thus may possibly be an antibody. Inhibitory activity found in normal serum globulins and the non-IgG fractions of both normal and abnormal sera seriously interferes with attempts to use the TSH radioreceptor assay to study the hypothesized anti-TSH, receptor antibody in the serum of patients with Graves' disease.
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PMID:Serum protein inhibition of thyrotropin binding to human thyroid tissue. 4 74


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