Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
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The induction of peroxisome proliferation in rat liver was examined after administration of perfluoro-n-decanoic acid (PFDA, C10), perfluoro-n-octanoic acid (PFOA, C8), perfluoro-n-butyric acid (PFBA, C4), 1-H,1-H-pentadecafluoro-n-octanol (PFOL, C8) perfluorododecane (PFD, C12), and perfluorooctane (PFO, C8). The peroxisome proliferation in the liver was detected by the following methods; 1) measurement of liver weight, 2) assay of hepatic catalase activity, 3) analysis of 600 X g supernatant of liver homogenates by SDS-polyacrylamide gel electrophoresis to observe the induction of the bifunctional enoyl-CoA hydratase in peroxisomes (80K-protein) and 4) observation by electron microscopy. The oral administration of powdered chow containing 0.02%-PFOA and PFBA to male rats of the Sprague-Dawley strain for 2 weeks and the single intraperitoneal injection of corn oil mixed with PFDA, PFOA, and PFOL at the dose of 100 mg/kg induced peroxisome proliferation markedly. PFOL, which has two hydrogen atoms around the hydroxylated carbon, should be metabolized to PFOA, which is an active inducer. Perfluorinated paraffins, PFD and PFO, did not show any induction, indicating the importance of the carboxylic group in the molecule for the peroxisome proliferation. Although the participation of thyroid hormone cannot be excluded, PFOA appears to act directly on the liver.
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PMID:The induction of peroxisome proliferation in rat liver by perfluorinated fatty acids, metabolically inert derivatives of fatty acids. 406 51

For the extraction of soft keratins from bovine snout or human epidermis the best results were obtained with a detergent (sodium dodecyl sulphate, SDS) or hydrogen bond breaking agent (urea) in a reducing medium (2-mercaptoethanol, 2-ME). N-acetylcysteine was a little less effective. Keratins from both sources gave typical sets of protein bands with molecular weights between 40.000 and 70.000 daltons. Upon electrofocusing special precautions had to be taken to avoid reoxidation and reaggregation of protein subunits. Keratins from aural cholesteatomas were obtained by extraction with SDA and 2-ME, with N-acetylcysteine alone and to a lesser extent with urea and 2-ME. The pattern of these keratins on SDS-gel is less complicated than that obtained from human skin or bovine snout. Histophotometric results argue for a clear analogy between the nuclear DNA metabolism in normal skin epidermis and cholesteatoma matrix. The only differences of potential relevance are the much wider range of the nuclear DNA amount in cholesteatoma stratum basale cells compared with basal cells in normal epidermis, and the higher persistence of nuclear DNA in cholesteatoma stratum granulosum, indicating postponement of keratinocyte terminal differentiation.
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PMID:Structural and topological studies of cholesteatoma proteins, in relation to the keratinization process. 616 57

The nitrogen-fixing, aerobic hydrogen-oxidizing bacterium Alcaligenes latus forms hydrogenase when growing lithoautotrophically with hydrogen as electron donor and carbon dioxide as sole carbon source or when growing heterotrophically with N2 as sole nitrogen source. The hydrogenase is membrane-bound and relatively oxygen-sensitive. The enzymes formed under both conditions are identical on the basis of the following criteria: molecular mass, mobility in polyacrylamide gel electrophoresis, Km value for hydrogen (methylene blue reduction), stability properties, localization, and cross-reactivity to antibodies raised against the 'autotrophic' hydrogenase. The hydrogenase was solubilized by Triton X-100 and deoxycholate treatment and purified by ammonium sulfate precipitation and chromatography on Phenyl-Sepharose C1-4B, DEAE-Sephacel and Matrix Gel Red A under hydrogen to homogeneity to a specific activity of 113 mumol H2 oxidized/min per mg protein (methylene blue reduction). SDS gel electrophoresis revealed two nonidentical subunits of molecular weights of 67 000 and 34 000, corresponding to a total molecular weight of 101 000. The pure enzyme was able to reduce FAD, FMN, riboflavin, flavodoxin isolated from Megasphaera elsdenii, menadione and horse heart cytochrome c as well as various artificial electron acceptors. The reversibility of the hydrogenase function was demonstrated by H2 evolution from reduced methyl viologen.
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PMID:Purification and properties of the membrane-bound hydrogenase from N2-fixing Alcaligenes latus. 630 22

Pig intestinal brush borders (BB) were radiolabeled by iodination using the lactoperoxidase-hydrogen peroxide procedure. The BB were then detergent solubilized, centrifuged to remove particulate material, and chromatographed on Sepharose CL-4B. The fractions were incubated with K88+ E. coli using an in vitro binding assay. Binding of the iodinated membranes to K88+ E. coli occurred throughout a wide range of molecular weight components, in excess of 690K daltons to near 25K daltons. The system utilizing intact K88+ E. coli and solubilized BB was shown to be saturable. Prior contact of K88+ E. coli with nonradiolabeled membranes or specific antibodies to K88+ pili inhibited binding of the radiolabeled BB. Simple sugars were tested for their ability to block binding of the labeled BB; partial inhibition occurred with galactose (17.9%), galactosamine (32%), glucose (10.6%), and N-acetylglucosamine (32%). Calcium enhanced binding with as little as 10 microM. A 10 x increase in binding occurred with 500 microM calcium. Affinity chromatography using K88+ pili coupled on agarose beads avidly bound the labeled BB. The receptor membranes were eluted with high molar concentrations of salt, however considerable degradation occurred. Despite low yields from the affinity system, receptor membranes with higher binding activities were recovered. Protein: glycoprotein ratios were 1:4. Elution with SDS and electrophoresis on 12.5% polyacrylamide gels in the presence of a reducing agent produced two major subunits 35--32K and 23K daltons. These components were recovered from the gels and retained their binding activity. This information suggests that the intestinal receptor responsible for binding of K88+ E. coli is a glycoprotein, that in the native state exists in multimeric forms.
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PMID:Soluble pig intestinal cell membrane components with affinities for E. coli K88+ antigen. 641 Jan 80

An intracellular N-terminal exopeptidase isolated from cell extracts of Streptococcus durans has been purified 470-fold to homogeneity (specific activity of 12.0 mumol/min per mg). In the absence of thiol compounds, the purified aminopeptidase undergoes a slow oxidation with a 70% loss of activity, which can be restored by the addition of 2 mM beta-mercaptoethanol. The purified aminopeptidase (Mr 300000) preferred L-peptide and arylamide substrates with small nonpolar or basic side chains. SDS electrophoresis yielded a single protein band corresponding to a molecular weight of 49400, suggesting that the native enzyme is a hexameric protein. The enzyme-catalyzed hydrolysis of L-alanyl-p-nitroanilide exhibited a bell-shaped pH dependence for log Vmax/Km (pK1 = 6.35; pK2 = 8.50) while the log Vmax versus pH profile showed only an acid limb (pK = 6.35). Methylene blue-sensitized photooxidation of the enzyme resulted in the complete loss of activity, while L-leucine, a competitive inhibitor, partially protected against this inactivation. Amino acid analysis indicated that this photooxidative loss of activity corresponded to the modification of one histidine residue per enzyme monomer. N-Ethylmaleimide (100 mM) caused a 78% reduction in enzyme activity. Treatment of the enzyme with 1.0 mM hydrogen peroxide resulted in the oxidation of two cysteine residues per enzyme monomer and caused a 70% decrease in the catalytic activity.
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PMID:Purification and characterization of an intracellular N-terminal exopeptidase from Streptococcus durans. 643 Mar 50

Proteins involved in the attachment of eosinophils to immobilized antigen-antibody complexes were isolated. Eosinophils, purified from normal human peripheral blood, were surface labelled with 125I-iodide in the presence of lactoperoxidase and hydrogen peroxide. Immobilized immune complexes were prepared by covalent coupling of tetanus toxoid antigen to cellulose and treatment of the fixed antigen with human anti-tetanus IgG. Intact cells were allowed to interact with the antigen-antibody complex and the cells were then lysed in situ with a salt solution containing the non-ionic detergent NP40. After exhaustive washing to remove unattached proteins, the bound proteins were eluted with a buffer containing mercaptoethanol with or without SDS. A major protein of mol. wt 16K and a minor protein of mol. wt 18K were isolated. These proteins were unaffected by the temperature of attachment of eosinophils to the fixed IgG antigen complexes or by the presence of protease inhibitors and did not therefore appear to be proteolytic cleavage products.
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PMID:Surface proteins of the human eosinophil. I. Isolation of eosinophil IgG binding proteins. 673 78

In previous publications (Muller, W.A., R.M. Steinman, Z.A. Cohn. 1980, J.Cell Biol. 86:292-314), we found that the membrane of macrophage phagolysosomes could be selectively radioiodinated in living cells, The technique required phagocytosis of lactoperoxidase covalently coupled to latex spheres (LPO-latex), followed by iodination on ice with Na(125)I and hydrogen peroxide. In this paper, we use the LPO-latex system to further analyze the composition and recycling of phagocytic vacuole membrane. Three approaches were employed to examine the polypeptide composition of the phagolysosome (PL) and plasma membranes (PM). (a) The efficiency of intracellular iodination was increased by increasing lysosomal pH with chloroquine. By one-dimensional SDS PAGE, the heavily labeled chloroquine-treated PL exhibited the same labeled polypeptides as PM iodinated extracellularly with LPO-latex. (b) Iodinated PL and PM were compared by two-dimensional gel electrophoresis. No differences in the isoelectric point and molecular weight of the major iodinated species were detected. (c) Quantitative immune precipitation was performed with five specific antibodies directed against cell surface antigens. Four antibodies precipitated similar relative amounts of labeled antigen on the cell surface and endocytic vacuole. One antibody, secreted by hybridoma 2.6, detected a 21-kdalton polypeptide that was enriched sevenfold in PL membrane. This enrichment was cell surface-derived, since the amount of labeled 2.6 was increased sevenfold when iodinated PM was driven into the cell during latex uptake. Therefore, intracellular iodination primarily detects PL proteins that are identical to their PM counterparts. Additional studies employed electron microscope autoradiography to monitor the centrifugal flow of radiolabeled polypeptides from PL to PM. Cells were iodinated intralysosomally and returned to culture for only 5-10 min at 37 degrees C. Most of the cell-associated label then redistributed to the cell surface or its adjacent area. Significant movement out of the lysosome compartment occurred even at 2 degrees C and 22 degrees C. Extensive and rapid membrane flow through the secondary lysosome presumably contributes to the great similarity between PM and PL membrane polypeptides.
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PMID:Membrane proteins of the vacuolar system. III. Further studies on the composition and recycling of endocytic vacuole membrane in cultured macrophages. 682 50

Choline oxidase from Alcaligenes sp. catalyzed the oxidation of choline and betaine aldehyde to betaine with concomitant consumption of oxygen and production of hydrogen peroxide. The values of Km for choline and betaine aldehyde were 0.87 and 6.2 mM, respectively. The molecular weight of the enzyme was estimated to be 66,000 by SDS-gel electrophoresis and 72,000 by gel-filtration using a high performance liquid chromatograph. The prosthetic group of the enzyme was identified as 8 alpha-[N(3)-histidyl]-FAD from the electrophoretic mobility at pH 6.25 of the hydrolysate of the methylated histidylflavin. The visible absorption spectrum of the enzyme showed peaks at 358 and 453 nm and a shoulder at about 480 nm. The covalently bound FAD was reduced on addition of either choline or betaine aldehyde under anaerobic conditions and was reoxidized by aeration. The enzyme was found to contain 1 mol of FAD per mol enzyme. Amino acid analysis of a purified flavin peptide gave the following molar ratios of amino acids to flavin: pro(1), Asp + Asn(3), Ser(1), His(1), and Arg(1). Aspartic acid was the N-terminal amino acid. The partial sequence of amino acids in the flavin peptide was as follows: Formula (See Text).
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PMID:Identification and properties of the prosthetic group of choline oxidase from Alcaligenes sp. 699 83

The periplasmic hydrogenase of Desulfovibrio desulfuricans was isolated and purified. Cells were washed with Tris-EDTA and the enzyme precipitated from the wash with ammonium sulfate. Absorption chromatography on DEAE and hydroxyapatite yielded the enzyme at better than 95% purity as judged by gel electrophoresis. The hydrogenase catalyzed the production of more than 9000 mumol H2/min mg protein(-1) from reduced methyl viologen at 37 degrees C. It is very stable and resists inactivation by heat (50% activity remained after 5 min in air at 65 degrees C) and by enzyme inhibitors (except N-ethylmaleimide and potassium ferricyanide). After storage in air at 4 degrees C for 1 month no activity was lost. The enzyme activity is sensitive to ionic environmental changes. With methyl viologen the optimum pH was 5.5 but with p-xylene polymeric viologen the optimum was about pH 7 but less sharp. The molecular weight was 47 X 10(3)(+/- 2 X 10(3), 52 X 10(3)(+/- X 10(3), and 56 X 19(3)(+/- 2 X 10(3) by SDS-gel electrophoresis, gel chromatography, and sedimentation equilibrium, respectively, and the isoelectric point was at pH 6.0. They enzyme might be useful in the production of hydrogen from water and solar energy.
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PMID:Purification and properties of the periplasmic hydrogenase from Desulfovibrio desulfuricans. 700 65

Binding of RecA protein to conventional anti-parallel poly(dA).2poly(dT) triplex DNA has been studied using flow linear dichroism spectroscopy. The association requires the presence of cofactor analog adenosine 5'-O-3-thiotriphosphate (ATP gamma S) and occurs with a rate similar to that for the association of RecA to double-stranded poly(dA).poly(dT) DNA. The binding of RecA to DNA stiffens the nucleotide chain, as evidenced from high orientation already at low shear rates, and the complex with triplex DNA appears to be at least as stiff as that with the duplex DNA. Therefore, the observation of a lower magnitude of the LD spectrum at 260 nm, in the triplex-RecA compared to the duplex-RecA complex, but retained magnitude of protein LD at 280 nm, indicates a markedly impaired orientation of nucleo-bases, possibly reflecting a perturbation by RecA on the third strand making its bases deviate strongly from perpendicularity. The circular dichroism spectrum, appearing immediately after dissociation of RecA by SDS, suggests an intact triplex structure, meaning that complexation with RecA has not dissociated the third strand. In conclusion, binding of RecA to triplex DNA does not modify the main organisation of the strands, but could affect the base-base interactions between them. Tilted bases could reflect a conformational change that RecA imposes also on the biological intermediate triplex structure to relax the base-base hydrogen bonding between the DNA strands.
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PMID:Binding of RecA to anti-parallel poly(dA).2poly(dT) triple helix DNA. 757 46


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