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:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microsomal AMP-deaminase was solubilized by 0.5 M KCl after treatment of microsomal membranes with 0.12 M KCl. Using disc-electrophoresis in polyacrylamide gel in the presence of sodium dodecyl sulfate one major protein component (mol. weight about 90 000) and three minor ones with molecular weights of 110 000, 80 000, and 60 000 were found in the soluble fraction. In addition to proteins, the fraction was found in the soluble fraction. In addition to proteins, the fraction was found to contain a small amount of phospholipids. The deaminase found in the solution may be reconstructed into the membranes at a decrease in KCl concentration, part of enzyme being bound in the inactive form under excess of the soluble fraction. Deaminase binding to the membranes is unaffected by the changes within the pH range of 6.2--7.8 and temperature range of 4--10 degrees C. It is assumed that AMP-deaminase is bound to other membrane components by electrostatic bonds.
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PMID:[Solubilization and reconstruction of microsomal AMP-deaminase from skeletal muscles]. 2 Jan 65

Formamidase from rat liver proved to be microheterogenous. After preparative isoelectric focusing in density gradient columns, two peaks of formamidase with identical substrate specificity were identified. By analytical focusing in thin layers of polyacrylamide or Sephadex G-75 SF, even five bands could be separated. Their isoelectric points were 4.75, 4.78, 4.82, 4.92 (main band) and 5.11, but their Michaelis constants did not differ significantly (54 to 62 mumol/l). An identical molecular weight of 34700 +/- 3200 for all bands was determined by disc electrophoresis. This value was confirmed by sedimentation analyses (so20,w = 3.00 S) and electrophoresis in the presence of sodium dodecyl-sulfate (Mr 34900 +/- 2300), which only gave a single band. The homogeneity was also confirmed by electrophoresis in the presence of 6M urea. Repeated disc electrophoresis of focusing under native conditions with single, isolated formamidases again resulted in different bands which were identified, not only by Coomassie Blue, but also by their hydrolytic cleavage of naphthyl acetate. Formamidase showed neither proteolytic nor asparagine-amidohydrolase activity and oligosaccharide conjugates were not detectable. Ampholytes, buffer ions, pH and peroxodisulfate did not affect the heterogeneity. "Initial burst" measurements with diethyl(4-nitrophenyl) phosphate yielded an equivalent weight of 36,300. Formylkynurenine reduced this inhibition very effectively. Thus, an extraordinary reactive serine residue appeared to be located in the catalytic site of formamidase. A participation of sulfhydrylgroups in the inactivating reaction of arsenite was excluded although two such groups were detected by 5,5'-dithiobis(2-nitrobenzoic acid). N-Bromosuccinimide reacted primarily with one of the nine tryptophan residues without loss of enzymatic activity, but a 18.6-fold excess of this reagent resulted in a complete loss of activity. The reaction rates of the most effective inhibitors and of the protective action of formylkynurenine were determined. Thus, formamidase must clearly be distinguished from typical serine esterases and proteases.
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PMID:[Formamidase--microheterogeneity, catalytic properties and inhibitors (author's transl)]. 8 81

The 16S and 8S forms of acetylcholinesterase (AchE), which are composed of an elongated tail structure in addition to the more globular catalytic subunits, were extracted and purified from membranes from Torpedo californica electric organs. Their subunit compositions and quaternary structures were compared with 11S lytic enzyme which is derived from collagenase or trypsin treatment of the membranes and devoid of the tail unit. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the absence of reducing agent, appreciable populations of monomeric through tetrameric species are observed for the 11S form. Under the same conditions, the 16S form yields only monomer and dimer in addition to a higher molecular weight species. If complete reduction is effected, only the 80,000 molecular weight monomer is dominant for both the 11S and 16S forms. Cross-linking of the 11S form by dimethyl suberimidate followed by reduction yields monomer through tetramer in descending frequency, while the 16S form again shows a high molecular weight species. A comparison of the composition of the 11S and 16S forms reveals that the latter has an increased glycine content, and 1.1 and 0.3 mol % hydroxyproline and hydroxylysine, respectively. Collagenases that have been purified to homogencity and are devoid of amidase and caseinolytic activity, but active against native collagen, will convert 16S acetylcholinesterase to the 11S form. Thus, composition and substrate behavior of the 16S enzyme are indicative of the tail unit containing a collagen-like sequence. A membrane fraction enriched in acetylcholinesterase and components of basement membrane can be separated from the major portion of the membrane protein. The 16S but not the 11S form reassociates selectively with this membrane fraction. These findings reveal distinct similarities between the tail unit of acetylcholinesterase and basement membrane components and suggest a primary association of AchE with the basement membrane.
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PMID:Molecular forms of acetylcholinesterase from Torpedo californica: their relationship to synaptic membranes. 17 42

An enzyme catalyzing the deamination of the cytosine moiety of blasticidin S was extracted from a fungal strain that belongs to Aspergillus terreus. The enzyme was purified with ammonium sulfate fractionation, Sephadex G-100 column and DEAE cellulose column chromatography, followed by preparative polyacrylamide gel electrophoresis. Blasticidin S deaminase could be separated easily from co-existing cytidine deaminase by DEAE column chromatography or gel electrophoresis, and preliminary study on the substrate specificity showed that this enzyme acts on blasticidin S derivatives, such as cytomycin and acetylblasticidin S, but not on cytosine, cytidine, purine bases or their nucleosides. Blasticidin S deaminase could be induced by the addition of blasticidin S to the culture, and sulfhydryl compounds, such as mercaptoethanol, were effective in protecting the enzyme from inactivation. The homogeneity of the enzyme was examined by both sedimentation analysis and polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were found to be around 30,000 and 4.35, respectively. Some other properties were also examined.
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PMID:Isolation and purification of blasticidin S deaminase from Aspergillus terreus. 23 72

Protein C is a vitamin K-dependent protein, which exists in bovine plasma as a precursor of a serine protease. In this study, protein C was isolated to homogeneity from human plasma by barium citrate adsorption and elution, ammonium sulfate fractionation, DEAE-Sephadex chromatography, dextran sulfate agarose chromatography, and preparative polyacrylamide gel electrophoresis. Human protein C (M(r) = 62,000) contains 23% carbohydrate and is composed of a light chain (M(r) = 21,000) and a heavy chain (M(r) = 41,000) held together by a disulfide bond(s). The light chain has an amino-terminal sequence of Ala-Asn-Ser-Phe-Leu- and the heavy chain has an aminoterminal sequence of Asp-Pro-Glu-Asp-Gln. The residues that are identical to bovine protein C are underlined. Incubation of human protein C with human alpha-thrombin at an enzyme to substrate weight ratio of 1:50 resulted in the formation of activated protein C, an enzyme with serine amidase activity. In the activation reaction, the apparent molecular weight of the heavy chain decreased from 41,000 to 40,000 as determined by gel electrophoresis in the presence of sodium dodecyl sulfate. No apparent change in the molecular weight of the light chain was observed in the activation process. The heavy chain of human activated protein C also contains the active-site serine residue as evidenced by its ability to react with radiolabeled diisopropyl fluorophosphate. Human activated protein C markedly prolongs the kaolin-cephalin clotting time of human plasma, but not that of bovine plasma. The amidolytic and anticoagulant activities of human activated protein C were completely obviated by prior incubation of the enzyme with diisopropyl fluorophosphate. These results indicate that human protein C, like its bovine counterpart, exists in plasma as a zymogen and is converted to a serine protease by limited proteolysis with attendant anticoagulant activity.
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PMID:Human plasma protein C: isolation, characterization, and mechanism of activation by alpha-thrombin. 46 91

Threonine deaminase (L-theonine hydro-lyase (deaminating), E.C. 4.2.1.16) has been purified to homogeneity from extracts of Saccharomyces cerevisiae. When purified 1200-fold, the enzyme is homogeneous by the criterion of sodium dodecyl sulfate-polyacrylamide electrophoresis. The reduced and alkylated protein has a molecular weight of approximately 50,000 daltons, one-fourth the value determined previously for the intact enzyme. The purified enzyme exhibits homotropic effects with the substrate; these effects are descresed in the presence of DL-allothreonine, a competitive inhibitor. Half-maximal velocity is achieved at 34 mM L-threonine in the absence of other effectors. L-isoleucine both stimulates at low (0.01-0.05 mM) concentrations and inhibits at high (0.1-1.0 mM) concentrations. Valine activates the enzyme in the absence of isoleucine ; in the presence of isoleucine it reverses inhibition.
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PMID:Purification and properties of threonine deaminase from Saccharomyces cerevisiae. 78 58

The autolysins of Bacillus subtilis 168 were analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis with substrate-containing gels. Four bands of vegetative autolytic activity of 90, 50, 34, and 30 kDa (bands A1 to A4) were detected in SDS and LiCl extracts and in native cell walls by using B. subtilis 168 vegetative cell walls as the substrate incorporated in the gel. The four enzyme activities showed different substrate specificities and sensitivities to various chemical treatments. The autolysin profile was not medium dependent and remained constant during vegetative growth. During sporulation, band A4 greatly increased in activity just prior to mother-cell lysis. No germination-associated changes in the profile were observed, although a soluble 41-kDa endospore-associated cortex-lytic enzyme was found. By using insertionally inactivated mutants, bands A1 and A2 were positively identified as the previously characterized 90-kDa glucosaminidase and 50-kDa amidase, respectively. The common filamentous phenotype of various regulatory mutants could not be correlated to specific changes in the autolysin profile.
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PMID:Analysis of the autolysins of Bacillus subtilis 168 during vegetative growth and differentiation by using renaturing polyacrylamide gel electrophoresis. 134 11

Human skin fibroblast lines of the infantile form of neuronal ceroid lipofuscinosis and control lines were cultured in the presence of [3H]glucosamine plus [3H]mannose and [35S]methionine. The labeled glycoconjugates were compared by quantitative polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The infantile form of the disease showed a 75% decrease of four glycoprotein components of M(r) 120-140 kDa. These components appeared to be N-linked glycoproteins as peptide-N4-(N-acetyl-beta-glucosaminyl) asparagine amidase (PNGase F) released 86-96% of the labeled carbohydrate from the labeled protein. These results suggest that the infantile form of this disease may be characterized by abnormalities in glycoconjugate metabolism leading to reduction of specific glycoproteins.
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PMID:Glycoprotein metabolism in neuronal ceroid lipofuscinosis fibroblasts. 141 45

L-alpha-aminocaprolactam hydrolase possessing the L lysine amidase activity was isolated from Klebsiella aerogenes and purified. The procedure of enzymes purification included cell destruction on USDN-I, fractionation by ammonium sulfate, gel chromatography on G-200. The preparation of the purified enzyme possessed specific activity of 50 mumol of lysin per 1 mg of protein per hour. Km was 2.6 mM in case of phosphate buffer (ph 7.2) for I-alpha-aminocaprolactam. Besides L-alpha-aminocaprolactam the enzyme hydrolyses lysine amide, leucine amide tryptophanamide. Magnesium ions are necessary for manifestation of catalytic activity of the enzyme.
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PMID:[Isolation and various properties of alpha-aminocaprolactam hydrolase from Klebsiella aerogenes]. 151 39

Antisera against purified autolytic N-acetylmuramyl-L-alanine amidase from Bacillus subtilis 168 were prepared in rabbits. They neutralized the enzymatic action of the purified amidase acting on isolated sodium dodecyl sulfate (SDS)-treated walls from the same organism. They also inhibited the lysis of native walls, but only after the walls lysed partially. Amidase adsorbed to insoluble walls still combined with antibody. Antisera did not stop the lysis of whole cells. Lowicryl HM20 sections of both strain 168 and its autolytic mutant strain FJ6 were prepared by the progressive-lowering-of-temperature technique, immunolabeled with the antisera, and visualized with colloidal gold particles as markers. The highest concentration of gold particles seemed to be in the septa of dividing cells, followed by the side walls. There was some labeling of the cytoplasm. Adsorption of sera with SDS-treated walls reduced the overall labeling of sections considerably but did not alter the relative intracellular distribution of particles. The results for strains 168 and FJ6 were similar. Labeling of SDS-treated walls unexpectedly revealed the presence of a wall-bound amidase fraction.
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PMID:Intracellular location of the autolytic N-acetylmuramyl-L-alanine amidase in Bacillus subtilis 168 and in an autolysis-deficient mutant by immunoelectron microscopy. 167 87


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