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Sample records for udp glucuronic acid

  1. Molecular cloning of a novel glucuronokinase/putative pyrophosphorylase from zebrafish acting in an UDP-glucuronic acid salvage pathway.

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    Roman Gangl

    Full Text Available In animals, the main precursor for glycosaminoglycan and furthermore proteoglycan biosynthesis, like hyaluronic acid, is UDP-glucuronic acid, which is synthesized via the nucleotide sugar oxidation pathway. Mutations in this pathway cause severe developmental defects (deficiency in the initiation of heart valve formation. In plants, UDP-glucuronic acid is synthesized via two independent pathways. Beside the nucleotide sugar oxidation pathway, a second minor route to UDP-glucuronic acid exist termed the myo-inositol oxygenation pathway. Within this myo-inositol is ring cleaved into glucuronic acid, which is subsequently converted to UDP-glucuronic acid by glucuronokinase and UDP-sugar pyrophosphorylase. Here we report on a similar, but bifunctional enzyme from zebrafish (Danio rerio which has glucuronokinase/putative pyrophosphorylase activity. The enzyme can convert glucuronic acid into UDP-glucuronic acid, required for completion of the alternative pathway to UDP-glucuronic acid via myo-inositol and thus establishes a so far unknown second route to UDP-glucuronic acid in animals. Glucuronokinase from zebrafish is a member of the GHMP-kinase superfamily having unique substrate specificity for glucuronic acid with a Km of 31 ± 8 µM and accepting ATP as the only phosphate donor (Km: 59 ± 9 µM. UDP-glucuronic acid pyrophosphorylase from zebrafish has homology to bacterial nucleotidyltransferases and requires UTP as nucleosid diphosphate donor. Genes for bifunctional glucuronokinase and putative UDP-glucuronic acid pyrophosphorylase are conserved among some groups of lower animals, including fishes, frogs, tunicates, and polychaeta, but are absent from mammals. The existence of a second pathway for UDP-glucuronic acid biosynthesis in zebrafish likely explains some previous contradictory finding in jekyll/ugdh zebrafish developmental mutants, which showed residual glycosaminoglycans and proteoglycans in knockout mutants of UDP

  2. 4-Methylumbelliferone inhibits hyaluronan synthesis by depletion of cellular UDP-glucuronic acid and downregulation of hyaluronan synthase 2 and 3

    International Nuclear Information System (INIS)

    Kultti, Anne; Pasonen-Seppaenen, Sanna; Jauhiainen, Marjo; Rilla, Kirsi J.; Kaernae, Riikka; Pyoeriae, Emma; Tammi, Raija H.; Tammi, Markku I.

    2009-01-01

    Hyaluronan accumulation on cancer cells and their surrounding stroma predicts an unfavourable disease outcome, suggesting that hyaluronan enhances tumor growth and spreading. 4-Methylumbelliferone (4-MU) inhibits hyaluronan synthesis and retards cancer spreading in experimental animals through mechanisms not fully understood. These mechanisms were studied in A2058 melanoma cells, MCF-7 and MDA-MB-361 breast, SKOV-3 ovarian and UT-SCC118 squamous carcinoma cells by analysing hyaluronan synthesis, UDP-glucuronic acid (UDP-GlcUA) content, and hyaluronan synthase (HAS) mRNA levels. The maximal inhibition in hyaluronan synthesis ranged 22-80% in the cell lines tested. Active glucuronidation of 4-MU produced large quantities of 4-MU-glucuronide, depleting the cellular UDP-GlcUA pool. The maximal reduction varied between 38 and 95%. 4-MU also downregulated HAS mRNA levels: HAS3 was 84-60% lower in MDA-MB-361, A2058 and SKOV-3 cells. HAS2 was the major isoenzyme in MCF-7 cells and lowered by 81%, similar to 88% in A2058 cells. These data indicate that both HAS substrate and HAS2 and/or HAS3 mRNA are targeted by 4-MU. Despite different target point sensitivities, the reduction of hyaluronan caused by 4-MU was associated with a significant inhibition of cell migration, proliferation and invasion, supporting the importance of hyaluronan synthesis in cancer, and the therapeutic potential of hyaluronan synthesis inhibition.

  3. 4-Methylumbelliferone inhibits hyaluronan synthesis by depletion of cellular UDP-glucuronic acid and downregulation of hyaluronan synthase 2 and 3

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    Kultti, Anne, E-mail: anne.kultti@uku.fi [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland); Pasonen-Seppaenen, Sanna [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland); Jauhiainen, Marjo [Department of Pharmaceutical Chemistry, University of Kuopio, FIN-70211 Kuopio (Finland); Rilla, Kirsi J.; Kaernae, Riikka; Pyoeriae, Emma; Tammi, Raija H.; Tammi, Markku I. [Institute of Biomedicine, Anatomy, University of Kuopio, P.O.B. 1627, FIN-70211 Kuopio (Finland)

    2009-07-01

    Hyaluronan accumulation on cancer cells and their surrounding stroma predicts an unfavourable disease outcome, suggesting that hyaluronan enhances tumor growth and spreading. 4-Methylumbelliferone (4-MU) inhibits hyaluronan synthesis and retards cancer spreading in experimental animals through mechanisms not fully understood. These mechanisms were studied in A2058 melanoma cells, MCF-7 and MDA-MB-361 breast, SKOV-3 ovarian and UT-SCC118 squamous carcinoma cells by analysing hyaluronan synthesis, UDP-glucuronic acid (UDP-GlcUA) content, and hyaluronan synthase (HAS) mRNA levels. The maximal inhibition in hyaluronan synthesis ranged 22-80% in the cell lines tested. Active glucuronidation of 4-MU produced large quantities of 4-MU-glucuronide, depleting the cellular UDP-GlcUA pool. The maximal reduction varied between 38 and 95%. 4-MU also downregulated HAS mRNA levels: HAS3 was 84-60% lower in MDA-MB-361, A2058 and SKOV-3 cells. HAS2 was the major isoenzyme in MCF-7 cells and lowered by 81%, similar to 88% in A2058 cells. These data indicate that both HAS substrate and HAS2 and/or HAS3 mRNA are targeted by 4-MU. Despite different target point sensitivities, the reduction of hyaluronan caused by 4-MU was associated with a significant inhibition of cell migration, proliferation and invasion, supporting the importance of hyaluronan synthesis in cancer, and the therapeutic potential of hyaluronan synthesis inhibition.

  4. Structures of bilirubin conjugates synthesized in vitro from bilirubin and uridine diphosphate glucuronic acid, uridine diphosphate glucose or uridine diphosphate xylose by preparations from rat liver

    NARCIS (Netherlands)

    Fevery, J.; Leroy, P.; van de Vijver, M.; Heirwegh, K. P.

    1972-01-01

    1. In incubation mixtures containing digitonin-activated or untreated preparations from rat liver, albumin-solubilized bilirubin as the acceptor substrate and (a) UDP-glucuronic acid, (b) UDP-glucose or (c) UDP-xylose as the sugar donor, formation of the following ester glycosides was demonstrated:

  5. The UDP-glucuronate decarboxylase gene family in Populus: structure, expression, and association genetics.

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    Qingzhang Du

    Full Text Available In woody crop plants, the oligosaccharide components of the cell wall are essential for important traits such as bioenergy content, growth, and structural wood properties. UDP-glucuronate decarboxylase (UXS is a key enzyme in the synthesis of UDP-xylose for the formation of xylans during cell wall biosynthesis. Here, we isolated a multigene family of seven members (PtUXS1-7 encoding UXS from Populus tomentosa, the first investigation of UXSs in a tree species. Analysis of gene structure and phylogeny showed that the PtUXS family could be divided into three groups (PtUXS1/4, PtUXS2/5, and PtUXS3/6/7, consistent with the tissue-specific expression patterns of each PtUXS. We further evaluated the functional consequences of nucleotide polymorphisms in PtUXS1. In total, 243 single-nucleotide polymorphisms (SNPs were identified, with a high frequency of SNPs (1/18 bp and nucleotide diversity (πT = 0.01033, θw = 0.01280. Linkage disequilibrium (LD analysis showed that LD did not extend over the entire gene (r (2<0.1, P<0.001, within 700 bp. SNP- and haplotype-based association analysis showed that nine SNPs (Q <0.10 and 12 haplotypes (P<0.05 were significantly associated with growth and wood property traits in the association population (426 individuals, with 2.70% to 12.37% of the phenotypic variation explained. Four significant single-marker associations (Q <0.10 were validated in a linkage mapping population of 1200 individuals. Also, RNA transcript accumulation varies among genotypic classes of SNP10 was further confirmed in the association population. This is the first comprehensive study of the UXS gene family in woody plants, and lays the foundation for genetic improvements of wood properties and growth in trees using genetic engineering or marker-assisted breeding.

  6. Chromatographic, Spectrometric and NMR Characterization of a New Set of Glucuronic Acid Esters Synthesized by Lipase

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    Michel Marlier

    2007-01-01

    Full Text Available An enzymatic synthesis was developed on a new set of D-glucuronic acid esters and particularly the tetradecyl-D-glucopyranosiduronate also named tetradecyl D-glucuronate. Chromatographic analyses revealed the presence of the ester as a mixture of anomeric forms for carbon chain lengths superior to 12. TOF/MS and MS/MS studies confirmed the synthesis of glucuronic acid ester. The NMR study also confirmed the structure of glucuronic acid esters and clearly revealed an anomeric (α/β ratio equivalent to 3/2

  7. Separation and purification of hyaluronic acid by glucuronic acid imprinted microbeads

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    Akdamar, H.Acelya; Sarioezlue, Nalan Yilmaz [Department of Biology, Anadolu University, Eskisehir (Turkey); Ozcan, Ayca Atilir; Ersoez, Arzu [Department of Chemistry, Anadolu University, Eskisehir (Turkey); Denizli, Adil [Department of Chemistry, Hacettepe University, Ankara (Turkey); Say, Ridvan, E-mail: rsay@anadolu.edu.tr [Department of Chemistry, Anadolu University, Eskisehir (Turkey); BIBAM (Plant, Drug and Scientific Researches Center), Anadolu University, Eskisehir (Turkey)

    2009-05-05

    The purification of hyaluronic acid (HA) is relatively significant to use in biomedical applications. The structure of HA is formed by the repetitive units of glucuronic acid and N-acetyl glucosamine. In this study, glucuronic acid-imprinted microbeads have been supplied for the purification of HA from cell culture (Streptococcus equi). Histidine-functional monomer, methacryloylamidohistidine (MAH) was chosen as the metal-complexing monomer. The glucuronic acid-imprinted poly(ethyleneglycoldimethacrylate-MAH-Copper(II)) [p(EDMA-MAH-Cu{sup 2+})] microbeads have been synthesized by typical suspension polymerization procedure. The template glucuronic acid has been removed by employing 5 M methanolic KOH solution. p(EDMA-MAH-Cu{sup 2+}) microbeads have been characterized by elemental analysis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) images and swelling studies. Moreover, HA adsorption experiments have been performed in a batch experimental set-up. Purification of HA from cell culture supernatant has been also investigated by determining the hyaluronidase activity using purified HA as substrate. The glucuronic acid imprinted p(EDMA-MAH-Cu{sup 2+}) particles can be used many times with no significant loss in adsorption capacities. Also, the selectivity of prepared molecular imprinted polymers (MIP) has been examined. Results have showed that MIP particles are 19 times more selective for glucuronic acid than N-acetylglucose amine.

  8. UDP-glucuronyltransferase-catalyzed deconjugation of bilirubin monoglucuronide

    NARCIS (Netherlands)

    Cuypers, H. T.; ter Haar, E. M.; Jansen, P. L.

    1984-01-01

    Bilirubin monoglucuronide is rapidly deconjugated when incubated with UDP and rat liver microsomal preparations at pH 5.1. The following evidence was found that this reaction is catalyzed by UDP-glucuronyltransferase: (i) unconjugated bilirubin and UDP-glucuronic acid were identified as the reaction

  9. CHARACTERIZATION OF HUMAN LIVER MICROSOMAL UDP-GLYCOSYLTRANSFERASES USING PHOTOAFFINITY ANALOGS

    NARCIS (Netherlands)

    LITTLE, JM; DRAKE, RR; VONK, R; KUIPERS, F; LESTER, R; RADOMINSKA, A

    The photoaffinity analogs [beta-P-32]5-azido-UDP-glucuronic acid ([P-32]5N3UDP-GlcUA) and [beta-P-32]5-azido-UDP-glucose ([P-32]5N(3)UDP-Glc) were used to characterize UDP-glycosyl-transferases of microsomes prepared from human liver. Photoincorporation of both probes into proteins in the 50- to

  10. Arabidopsis GUX Proteins Are Glucuronyltransferases Responsible for the Addition of Glucuronic Acid Side Chains onto Xylan

    Science.gov (United States)

    Xylan, the second most abundant cell wall polysaccharide, is composed of a linear backbone of β-(1,4)-linked xylosyl residues that are often substituted with sugar side chains, such as glucuronic acid (GlcA) and methylglucuronic acid (MeGlcA). It has recently been shown that muta...

  11. 40 CFR 721.2076 - D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...

    Science.gov (United States)

    2010-07-01

    ...-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium salt. 721.2076 Section 721...-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium potassium sodium... identified as D-Glucuronic acid, polymer with 6-deoxy-L-mannose and D-glucose, acetate, calcium magnesium...

  12. Cloning, expression, purification, crystallization and X-ray crystallographic analysis of glucuronic acid dehydrogenase from Chromohalobacter salexigens

    International Nuclear Information System (INIS)

    Ahn, Jae-Woo; Lee, Shin Youp; Kim, Sangwoo; Cho, Sun Ja; Lee, Sun Bok; Kim, Kyung-Jin

    2011-01-01

    Recombinant glucuronic acid dehydrogenase from the halophilic bacterium Chromohalobacter salexigens has been crystallized and X-ray diffraction data collected to a maximum resolution of 2.1 Å. Glucuronic acid dehydrogenase (GluUADH), the product of the Csal-2474 gene from the halophilic bacterium Chromohalobacter salexigens DSM 3043, is an enzyme with potential use in the conversion of glucuronic acid in seaweed biomass to fuels and chemicals. GluUADH is an enzyme that catalyzes the oxidation of glucuronic acid (GluUA) and galacturonic acid (GalUA) and has a preference for NAD + rather than NADP + as a cofactor. Recombinant GluUADH was crystallized in the presence of 0.2 M calcium acetate, 0.1 M Tris–HCl pH 7.0 and 20% PEG 3000 at 295 K. X-ray diffraction data were collected to a maximum resolution of 2.1 Å. The GluUADH crystal belonged to space group P6 3 , with unit-cell parameters a = b = 122.58, c = 150.49 Å, γ = 120°. With one molecule per asymmetric unit, the crystal volume per unit protein weight (V M ) is 2.78 Å 3 Da −1 . The structure was solved by the single anomalous dispersion method and structure refinement is in progress

  13. Glucuronoyl Esterase Screening and Characterization Assays Utilizing Commercially Available Benzyl Glucuronic Acid Ester

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    Hampus Sunner

    2015-09-01

    Full Text Available Research on glucuronoyl esterases (GEs has been hampered by the lack of enzyme assays based on easily obtainable substrates. While benzyl d-glucuronic acid ester (BnGlcA is a commercially available substrate that can be used for GE assays, several considerations regarding substrate instability, limited solubility and low apparent affinities should be made. In this work we discuss the factors that are important when using BnGlcA for assaying GE activity and show how these can be applied when designing BnGlcA-based GE assays for different applications: a thin-layer chromatography assay for qualitative activity detection, a coupled-enzyme spectrophotometric assay that can be used for high-throughput screening or general activity determinations and a HPLC-based detection method allowing kinetic determinations. The three-level experimental procedure not merely facilitates routine, fast and simple biochemical characterizations but it can also give rise to the discovery of different GEs through an extensive screening of heterologous Genomic and Metagenomic expression libraries.

  14. Conversion of cheese whey into a fucose- and glucuronic acid-rich extracellular polysaccharide by Enterobacter A47.

    Science.gov (United States)

    Antunes, Sílvia; Freitas, Filomena; Alves, Vítor D; Grandfils, Christian; Reis, Maria A M

    2015-09-20

    Cheese whey was used as the sole substrate for the production of extracellular polysaccharides (EPS) by Enterobacter A47. An EPS concentration of 6.40 g L(-1) was reached within 3.2 days of cultivation, corresponding to a volumetric productivity of 2.00 g L(-1) d(-1). The produced EPS was mainly composed of glucuronic acid (29 mol%) and fucose (29 mol%), with lower contents of glucose and galactose (21 mol% each) and a total acyl groups content of 32 wt.%. The polymer had an average molecular weight of 1.8×10(6) Da, with a polydispersity index of 1.2, and an intrinsic viscosity of 8.0 dL g(-1). EPS aqueous solutions (1.0 wt.% in 0.01 M NaCl, at pH 8.0) presented a shear thinning behavior with a viscosity of the first Newtonian plateau approaching 0.1 Pas. This novel glucuronic acid-rich polymer possesses interesting rheological properties, which, together with its high content of glucuronic acid and fucose, two bioactive sugar monomers, confers it a great potential for use in high-value applications, such as cosmetics and pharmaceuticals. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

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    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P. [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico); Gurinov, Andrey [Research Resources Center for Magnetic Resonance, Saint Petersburg State University, Universitetskij pr. 26, 198504 St. Petersburg (Russian Federation); Ortiz, Genaro Gabriel [Laboratorio Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Carbajal Arízaga, Gregorio Guadalupe, E-mail: gregoriocarbajal@yahoo.com.mx [Departamento de Química, Universidad de Guadalajara, Marcelino García Barragán 1421, C.P. 44430, Guadalajara, Jalisco (Mexico)

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents.

  16. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids

    International Nuclear Information System (INIS)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P.; Gurinov, Andrey; Ortiz, Genaro Gabriel; Carbajal Arízaga, Gregorio Guadalupe

    2015-01-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488 nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. - Highlights: • Hydroxyapatite functionalized with glucuronic acid reduced oxidative stress in rats. • Functionalization with folic acid reduced oxidative stress in rats. • Dysprosium doping does not affect the crystalline structure of hydroxyapatite. • Dysprosium doped particles are visible in fluorescent microscope. • Dysprosium doped particles act as MRI contrast agents

  17. Dual responsive dysprosium-doped hydroxyapatite particles and toxicity reduction after functionalization with folic and glucuronic acids.

    Science.gov (United States)

    Sánchez Lafarga, Ana Karen; Pacheco Moisés, Fermín P; Gurinov, Andrey; Ortiz, Genaro Gabriel; Carbajal Arízaga, Gregorio Guadalupe

    2015-03-01

    The development of probes for biomedical applications demands materials with low toxicity levels besides fluorescence or magnetic properties to be detected by confocal microscopes or MRI resonators. Several drug delivery systems or other biomedical materials prepared with hydroxyapatite have been proposed, however, toxicity effects might arise when the size of particles is nanometric. In this study, hydroxyapatite functionalized with glucuronic or folic acids presented lower oxidative stress, measured from lipoperoxides and nitric oxide indicators in rats than pure hydroxyapatite. In separated experiments, hydroxyapatite was doped with dysprosium cations by coprecipitation producing a single crystal phase with fluorescent properties easily visualized by confocal microscopy when excited at 488nm. These particles also presented the ability to modify the proton relaxation time in T1 maps collected by magnetic resonance imaging. These modified hydroxyapatite nanoparticles could be candidates to design bimodal probes with low toxicity. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Bioactive and metal uptake studies of carboxymethyl chitosan-graft-D-glucuronic acid membranes for tissue engineering and environmental applications.

    Science.gov (United States)

    Jayakumar, R; Rajkumar, M; Freitas, H; Sudheesh Kumar, P T; Nair, S V; Furuike, T; Tamura, H

    2009-08-01

    Carboxymethyl chitosan-graft-D-glucuronic acid (CMCS-g-D-GA) was prepared by grafting D-GA onto CMCS in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and then the membranes were made from it. In this work, the bioactivity studies of CMCS-g-D-GA membranes were carried out and then characterized by SEM, CLSM, XRD and FT-IR. The CMCS-g-D-GA membranes were found to be bioactive. The adsorption of Ni2+, Zn2+ and Cu2+ ions onto CMCS-g-D-GA membranes has also been investigated. The maximum adsorption capacity of CMCS-g-D-GA for Ni2+, Zn2+ and Cu2+ was found to be 57, 56.4 and 70.2 mg/g, respectively. Hence, these membranes were useful for tissue engineering, environmental and water purification applications.

  19. Assignment of the human UDP glucuronosyltransferase gene (UGT1A1) to chromosome region 2q37

    NARCIS (Netherlands)

    van Es, H. H.; Bout, A.; Liu, J.; Anderson, L.; Duncan, A. M.; Bosma, P.; Oude Elferink, R.; Jansen, P. L.; Chowdhury, J. R.; Schurr, E.

    1993-01-01

    UDP glucuronosyltransferases (UGTs) comprise a multigene family of drug-metabolizing enzymes. The sub-family of UGTs that conjugate bilirubin and phenolic compounds with glucuronic acid has been termed UGT1A1. In man, UGT1A1 isoforms are encoded by a single gene, UGT1A1. Protein isoforms encoded by

  20. 4-O-methylation of glucuronic acid in Arabidopsis glucuronoxylan is catalyzed by a domain of unknown function family 579 protein

    OpenAIRE

    Urbanowicz, Breeanna R.; Peña, Maria J.; Ratnaparkhe, Supriya; Avci, Utku; Backe, Jason; Steet, Heather F.; Foston, Marcus; Li, Hongjia; O’Neill, Malcolm A.; Ragauskas, Arthur J.; Darvill, Alan G.; Wyman, Charles; Gilbert, Harry J.; York, William S.

    2012-01-01

    The hemicellulose 4-O-methyl glucuronoxylan is one of the principle components present in the secondary cell walls of eudicotyledonous plants. However, the biochemical mechanisms leading to the formation of this polysaccharide and the effects of modulating its structure on the physical properties of the cell wall are poorly understood. We have identified and functionally characterized an Arabidopsis glucuronoxylan methyltransferase (GXMT) that catalyzes 4-O-methylation of the glucuronic acid ...

  1. Non-critically phase-matched second harmonic generation and third order nonlinearity in organic crystal glucuronic acid γ-lactone

    Science.gov (United States)

    Saripalli, Ravi Kiran; Katturi, Naga Krishnakanth; Soma, Venugopal Rao; Bhat, H. L.; Elizabeth, Suja

    2017-12-01

    The linear, second order, and third order nonlinear optical properties of glucuronic acid γ-lactone single crystals were investigated. The optic axes and principal dielectric axes were identified through optical conoscopy and the principal refractive indices were obtained using the Brewster's angle method. Conic sections were observed which is perceived to be due to spontaneous non-collinear phase matching. The direction of collinear phase matching was determined and the deff evaluated in this direction was 0.71 pm/V. Open and closed aperture Z-scan measurements with femtosecond pulses revealed high third order nonlinearity in the form of self-defocusing, two-photon absorption, as well as saturable absorption.

  2. Characterization of an inducible UDP-glucose:salicylic acid O-glucosyltransferase from oat roots

    International Nuclear Information System (INIS)

    Yalpani, N.; Schulz, M.; Balke, N.E.

    1990-01-01

    Phytotoxicity of salicylic acid (SA), a phenolic acid that inhibits ion absorption in plant roots, is reduced in oat roots by the action of a UDP-glucose:SA glucosyltransferase (GTase). GTase activity, extracted from oat roots and assayed with [ 14 C]SA, was present at low constitutive levels but increased within 1.5 h of incubation of roots in 0.5 mM SA at pH 6.5. This induction was the result of de novo RNA and protein synthesis. Induction was highly specific towards SA as the inducer. The partially purified, soluble enzyme has a M t of about 50,000 and high specificity towards UDP-glucose as the sugar donor (K m = 0.28 mM) and SA as the glucose acceptor (K m = 0.11 mM). 2-D PAGE of [ 35 S]methionine-labeled proteins extracted from induced and uninduced roots revealed a candidate peptide representing the GTase. This peptide was also present on gels of partially purified GTase

  3. Down-regulation of UDP-glucose dehydrogenase affects glycosaminoglycans synthesis and motility in HCT-8 colorectal carcinoma cells

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    Wang, Tsung-Pao; Pan, Yun-Ru; Fu, Chien-Yu; Chang, Hwan-You, E-mail: hychang@life.nthu.edu.tw

    2010-10-15

    UDP-glucose dehydrogenase (UGDH) catalyzes oxidation of UDP-glucose to yield UDP-glucuronic acid, a precursor of hyaluronic acid (HA) and other glycosaminoglycans (GAGs) in extracellular matrix. Although association of extracellular matrix with cell proliferation and migration has been well documented, the importance of UGDH in these behaviors is not clear. Using UGDH-specific small interference RNA to treat HCT-8 colorectal carcinoma cells, a decrease in both mRNA and protein levels of UGDH, as well as the cellular UDP-glucuronic acid and GAG production was observed. Treatment of HCT-8 cells with either UGDH-specific siRNA or HA synthesis inhibitor 4-methylumbelliferone effectively delayed cell aggregation into multicellular spheroids and impaired cell motility in both three-dimensional collagen gel and transwell migration assays. The reduction in cell aggregation and migration rates could be restored by addition of exogenous HA. These results indicate that UGDH can regulate cell motility through the production of GAG. The enzyme may be a potential target for therapeutic intervention of colorectal cancers.

  4. aguA, the gene encoding an extracellular alpha-glucuronidase from Aspergillus tubingensis, is specifically induced on xylose and not on glucuronic acid.

    Science.gov (United States)

    de Vries, R P; Poulsen, C H; Madrid, S; Visser, J

    1998-01-01

    An extracellular alpha-glucuronidase was purified and characterized from a commercial Aspergillus preparation and from culture filtrate of Aspergillus tubingensis. The enzyme has a molecular mass of 107 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 112 kDa as determined by mass spectrometry, has a determined pI just below 5.2, and is stable at pH 6.0 for prolonged times. The pH optimum for the enzyme is between 4.5 and 6.0, and the temperature optimum is 70 degrees C. The alpha-glucuronidase is active mainly on small substituted xylo-oligomers but is also able to release a small amount of 4-O-methylglucuronic acid from birchwood xylan. The enzyme acts synergistically with endoxylanases and beta-xylosidase in the hydrolysis of xylan. The enzyme is N glycosylated and contains 14 putative N-glycosylation sites. The gene encoding this alpha-glucuronidase (aguA) was cloned from A. tubingensis. It consists of an open reading frame of 2,523 bp and contains no introns. The gene codes for a protein of 841 amino acids, containing a eukaryotic signal sequence of 20 amino acids. The mature protein has a predicted molecular mass of 91,790 Da and a calculated pI of 5.13. Multiple copies of the gene were introduced in A. tubingensis, and expression was studied in a highly overproducing transformant. The aguA gene was expressed on xylose, xylobiose, and xylan, similarly to genes encoding endoxylanases, suggesting a coordinate regulation of expression of xylanases and alpha-glucuronidase. Glucuronic acid did not induce the expression of aguA and also did not modulate the expression on xylose. Addition of glucose prevented expression of aguA on xylan but only reduced the expression on xylose.

  5. aguA, the Gene Encoding an Extracellular α-Glucuronidase from Aspergillus tubingensis, Is Specifically Induced on Xylose and Not on Glucuronic Acid

    Science.gov (United States)

    de Vries, Ronald P.; Poulsen, Charlotte H.; Madrid, Susan; Visser, Jaap

    1998-01-01

    An extracellular α-glucuronidase was purified and characterized from a commercial Aspergillus preparation and from culture filtrate of Aspergillus tubingensis. The enzyme has a molecular mass of 107 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 112 kDa as determined by mass spectrometry, has a determined pI just below 5.2, and is stable at pH 6.0 for prolonged times. The pH optimum for the enzyme is between 4.5 and 6.0, and the temperature optimum is 70°C. The α-glucuronidase is active mainly on small substituted xylo-oligomers but is also able to release a small amount of 4-O-methylglucuronic acid from birchwood xylan. The enzyme acts synergistically with endoxylanases and β-xylosidase in the hydrolysis of xylan. The enzyme is N glycosylated and contains 14 putative N-glycosylation sites. The gene encoding this α-glucuronidase (aguA) was cloned from A. tubingensis. It consists of an open reading frame of 2,523 bp and contains no introns. The gene codes for a protein of 841 amino acids, containing a eukaryotic signal sequence of 20 amino acids. The mature protein has a predicted molecular mass of 91,790 Da and a calculated pI of 5.13. Multiple copies of the gene were introduced in A. tubingensis, and expression was studied in a highly overproducing transformant. The aguA gene was expressed on xylose, xylobiose, and xylan, similarly to genes encoding endoxylanases, suggesting a coordinate regulation of expression of xylanases and α-glucuronidase. Glucuronic acid did not induce the expression of aguA and also did not modulate the expression on xylose. Addition of glucose prevented expression of aguA on xylan but only reduced the expression on xylose. PMID:9440512

  6. Crystal Structures of Active Fully Assembled Substrate- and Product-Bound Complexes of UDP-N-Acetylmuramic Acid:l-Alanine Ligase (MurC) from Haemophilus influenzae

    OpenAIRE

    Mol, Clifford D.; Brooun, Alexei; Dougan, Douglas R.; Hilgers, Mark T.; Tari, Leslie W.; Wijnands, Robert A.; Knuth, Mark W.; McRee, Duncan E.; Swanson, Ronald V.

    2003-01-01

    UDP-N-acetylmuramic acid:l-alanine ligase (MurC) catalyzes the addition of the first amino acid to the cytoplasmic precursor of the bacterial cell wall peptidoglycan. The crystal structures of Haemophilus influenzae MurC in complex with its substrate UDP-N-acetylmuramic acid (UNAM) and Mg2+ and of a fully assembled MurC complex with its product UDP-N-acetylmuramoyl-l-alanine (UMA), the nonhydrolyzable ATP analogue AMPPNP, and Mn2+ have been determined to 1.85- and 1.7-Å resolution, respective...

  7. Synthesis of UDP-apiose in Bacteria: The marine phototroph Geminicoccus roseus and the plant pathogen Xanthomonas pisi.

    Directory of Open Access Journals (Sweden)

    James Amor Smith

    Full Text Available The branched-chain sugar apiose was widely assumed to be synthesized only by plant species. In plants, apiose-containing polysaccharides are found in vascularized plant cell walls as the pectic polymers rhamnogalacturonan II and apiogalacturonan. Apiosylated secondary metabolites are also common in many plant species including ancestral avascular bryophytes and green algae. Apiosyl-residues have not been documented in bacteria. In a screen for new bacterial glycan structures, we detected small amounts of apiose in methanolic extracts of the aerobic phototroph Geminicoccus roseus and the pathogenic soil-dwelling bacteria Xanthomonas pisi. Apiose was also present in the cell pellet of X. pisi. Examination of these bacterial genomes uncovered genes with relatively low protein homology to plant UDP-apiose/UDP-xylose synthase (UAS. Phylogenetic analysis revealed that these bacterial UAS-like homologs belong in a clade distinct to UAS and separated from other nucleotide sugar biosynthetic enzymes. Recombinant expression of three bacterial UAS-like proteins demonstrates that they actively convert UDP-glucuronic acid to UDP-apiose and UDP-xylose. Both UDP-apiose and UDP-xylose were detectable in cell cultures of G. roseus and X. pisi. We could not, however, definitively identify the apiosides made by these bacteria, but the detection of apiosides coupled with the in vivo transcription of bUAS and production of UDP-apiose clearly demonstrate that these microbes have evolved the ability to incorporate apiose into glycans during their lifecycles. While this is the first report to describe enzymes for the formation of activated apiose in bacteria, the advantage of synthesizing apiose-containing glycans in bacteria remains unknown. The characteristics of bUAS and its products are discussed.

  8. Structural and Functional Analysis of Campylobacter jejuni PseG: a Udp-sugarhydrolase from the Pseudaminic Acid Biosynthetic Pathway

    Energy Technology Data Exchange (ETDEWEB)

    E Rangarajan; A Proteau; Q Cui; S Logan; Z Potetinova; D Whitfield; E Purisima; M Cygler; A Matte; et al.

    2011-12-31

    Flagella of the bacteria Helicobacter pylori and Campylobacter jejuni are important virulence determinants, whose proper assembly and function are dependent upon glycosylation at multiple positions by sialic acid-like sugars, such as 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-l-manno-nonulosonic acid (pseudaminic acid (Pse)). The fourth enzymatic step in the pseudaminic acid pathway, the hydrolysis of UDP-2,4-diacetamido-2,4,6-trideoxy-{beta}-l-altropyranose to generate 2,4-diacetamido-2,4,6-trideoxy-l-altropyranose, is performed by the nucleotide sugar hydrolase PseG. To better understand the molecular basis of the PseG catalytic reaction, we have determined the crystal structures of C. jejuni PseG in apo-form and as a complex with its UDP product at 1.8 and 1.85 {angstrom} resolution, respectively. In addition, molecular modeling was utilized to provide insight into the structure of the PseG-substrate complex. This modeling identifies a His{sup 17}-coordinated water molecule as the putative nucleophile and suggests the UDP-sugar substrate adopts a twist-boat conformation upon binding to PseG, enhancing the exposure of the anomeric bond cleaved and favoring inversion at C-1. Furthermore, based on these structures a series of amino acid substitution derivatives were constructed, altering residues within the active site, and each was kinetically characterized to examine its contribution to PseG catalysis. In conjunction with structural comparisons, the almost complete inactivation of the PseG H17F and H17L derivatives suggests that His{sup 17} functions as an active site base, thereby activating the nucleophilic water molecule for attack of the anomeric C-O bond of the UDP-sugar. As the PseG structure reveals similarity to those of glycosyltransferase family-28 members, in particular that of Escherichia coli MurG, these findings may also be of relevance for the mechanistic understanding of this important enzyme family.

  9. Isolation and purification of rat liver morphine UDP-glucuronosyltransferase

    International Nuclear Information System (INIS)

    Puig, J.F.; Tephly, T.R.

    1986-01-01

    The enhancement of rat liver microsomal morphine (M) and 4-hydroxybiphenyl (4-HBP) UDP-glucuronyltransferase (UDPGT) activities by phenobarbital treatment has been proposed to represent increased activity of a single enzyme form, GT-2. They have separated M and 4-HBP UDPGT activities from Emulgen 911-solubilized microsomes obtained from livers of phenobarbital-treated Wistar rats. A sensitive assay procedure was developed to quantify M-UDPGT and 4-HBP-UDPGT activities using 14 C-UDP-glucuronic acid (UDPGA) and reversed phase C-18 minicolumns whereby the radioactive glucuronides were differentially eluted from labeled UDPGA. Trisacryl DEAE, and chromatofocusing procedures were employed to separate M-UDPGT and 4-HBP-UDPGT in the presence of exogenous phosphatidylcholine (PC). The PC is necessary to stabilize UDPGT activities. M-UDPGT was isolated to apparent homogeneity and displayed a monomeric molecular weight of 56,000 daltons on SDS-PAGE. It reacted with M but not with 4-HBP, bilirubin, p-nitrophenol, testosterone, androsterone, estrone, 4-aminobiphenyl or α-naphthylamine. 4-HBP-UDPGT did not react with M. Therefore, M and 4-HBP glucuronidations are catalyzed by separate enzymes in rat liver microsomes

  10. The UDP-glucuronosyltransferases of the blood-brain barrier: their role in drug metabolism and detoxication

    Directory of Open Access Journals (Sweden)

    Mohamed eOuzzine

    2014-10-01

    Full Text Available UDP-glucuronosyltransferases (UGTs form a multigenic family of membrane-bound enzymes expressed in various tissues, including brain. They catalyze the formation of β-Dglucuronides from structurally unrelated substances (drugs, other xenobiotics, as well as endogenous compounds by the linkage of glucuronic acid from the high energy donor, UDP-αD-glucuronic acid. In brain, UGTs actively participate to the overall protection of the tissue against the intrusion of potentially harmful lipophilic substances that are metabolized as hydrophilic glucuronides. These metabolites are generally inactive, except for important pharmacologically glucuronides such as morphine-6-glucuronide. UGTs are mainly expressed in endothelial cells and astrocytes of the blood brain barrier. They are also associated to brain interfaces devoid of blood-brain barrier, such as circumventricular organ, pineal gland, pituitary gland and neuro-olfactory tissues. Beside their key-role as a detoxication barrier, UGTs play a role in the steady-state of endogenous compounds, like steroids or dopamine that participate to the function of the brain. UGT isoforms of family 1A, 2A, 2B and 3A are expressed in brain tissues to various levels and are known to present distinct but overlapping substrate specificity. The importance of these enzyme species with regard to the formation of toxic, pharmacologically or physiologically relevant glucuronides in the brain will be discussed.

  11. Synthesis of two hyaluronic-acid-related oligosaccharide 4-methoxyphenyl glycosides having a beta-D-glucuronic acid residue at the reducing end

    NARCIS (Netherlands)

    Halkes, K.M.; Slaghek, T.M.; Hypponen, T.K.; Kamerling, J.P.; Vliegenthart, J.F.G.

    1999-01-01

    Synthesis of two hyaluronic-acid-related oligosaccharides, the 4-methoxyphenyl β-glycosides of β-D-GlcpA-(1→3)-β-D-GlcpNAc-(1→4)-D-GlcpA and β-D-GlcpA-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3)- β-D-GJcpNAc-(1→4)-D-GlcpA, is described. D-Glucopyranosyluronic acid residues were obtained by selective

  12. Synthesis of two hyaluronic-acid-related oligosaccharide 4-methoxyphenyl glycosides having a β-D-glucuronic acid residue at the reducing end

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Halkes, K.M.; Slaghek, T.M.; Hyppönen, T.K.; Kamerling, J.P.

    1999-01-01

    Synthesis of two hyaluronic-acid-related oligosaccharides, the 4-methoxyphenyl beta-glycosides of beta-D-GlcpA-(1->3)-beta-D-GlcpNAc-(1->4)-D-GlcpA and beta-D-GlcpA-(1->3)-beta-D-GlcpNAc-(1->4)-beta-D-GlcpA-(1->3)-beta-D-GlcpNAc-(1->4)-D-GlcpA, is described. D-Glucopyranosyluronic acid residues were

  13. Crystal structures of active fully assembled substrate- and product-bound complexes of UDP-N-acetylmuramic acid:L-alanine ligase (MurC) from Haemophilus influenzae.

    Science.gov (United States)

    Mol, Clifford D; Brooun, Alexei; Dougan, Douglas R; Hilgers, Mark T; Tari, Leslie W; Wijnands, Robert A; Knuth, Mark W; McRee, Duncan E; Swanson, Ronald V

    2003-07-01

    UDP-N-acetylmuramic acid:L-alanine ligase (MurC) catalyzes the addition of the first amino acid to the cytoplasmic precursor of the bacterial cell wall peptidoglycan. The crystal structures of Haemophilus influenzae MurC in complex with its substrate UDP-N-acetylmuramic acid (UNAM) and Mg(2+) and of a fully assembled MurC complex with its product UDP-N-acetylmuramoyl-L-alanine (UMA), the nonhydrolyzable ATP analogue AMPPNP, and Mn(2+) have been determined to 1.85- and 1.7-A resolution, respectively. These structures reveal a conserved, three-domain architecture with the binding sites for UNAM and ATP formed at the domain interfaces: the N-terminal domain binds the UDP portion of UNAM, and the central and C-terminal domains form the ATP-binding site, while the C-terminal domain also positions the alanine. An active enzyme structure is thus assembled at the common domain interfaces when all three substrates are bound. The MurC active site clearly shows that the gamma-phosphate of AMPPNP is positioned between two bound metal ions, one of which also binds the reactive UNAM carboxylate, and that the alanine is oriented by interactions with the positively charged side chains of two MurC arginine residues and the negatively charged alanine carboxyl group. These results indicate that significant diversity exists in binding of the UDP moiety of the substrate by MurC and the subsequent ligases in the bacterial cell wall biosynthesis pathway and that alterations in the domain packing and tertiary structure allow the Mur ligases to bind sequentially larger UNAM peptide substrates.

  14. Functional and biochemical analysis of Chlamydia trachomatis MurC, an enzyme displaying UDP-N-acetylmuramate:amino acid ligase activity.

    Science.gov (United States)

    Hesse, Lars; Bostock, Julieanne; Dementin, Sebastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Chopra, Ian

    2003-11-01

    Chlamydiae are unusual obligate intracellular bacteria that cause serious infections in humans. Chlamydiae contain genes that appear to encode products with peptidoglycan biosynthetic activity. The organisms are also susceptible to antibiotics that inhibit peptidoglycan synthesis. However, chlamydiae do not synthesize detectable peptidoglycan. The paradox created by these observations is known as the chlamydial anomaly. The MurC enzyme of chlamydiae, which is synthesized as a bifunctional MurC-Ddl product, is expected to possess UDP-N-acetylmuramate (UDP-MurNAc):L-alanine ligase activity. In this paper we demonstrate that the MurC domain of the Chlamydia trachomatis bifunctional protein is functionally expressed in Escherichia coli, since it complements a conditional lethal E. coli mutant possessing a temperature-sensitive lesion in MurC. The recombinant MurC domain was overexpressed in and purified from E. coli. It displayed in vitro ATP-dependent UDP-MurNAc:L-alanine ligase activity, with a pH optimum of 8.0 and dependence upon magnesium ions (optimum concentration, 20 mM). Its substrate specificity was studied with three amino acids (L-alanine, L-serine, and glycine); comparable Vmax/Km values were obtained. Our results are consistent with the synthesis of a muramic acid-containing polymer in chlamydiae with UDP-MurNAc-pentapeptide as a precursor molecule. However, due to the lack of specificity of MurC activity in vitro, it is not obvious which amino acid is present in the first position of the pentapeptide.

  15. Cloning, expression, purification, crystallization and preliminary crystallographic studies of UgdG, an UDP-glucose dehydrogenase from Sphingomonas elodea ATCC 31461

    International Nuclear Information System (INIS)

    Rocha, Joana; Granja, Ana Teresa; Sá-Correia, Isabel; Fialho, Arsénio; Frazão, Carlos

    2009-01-01

    Crystals of S. elodea ATCC 31461 UDP-glucose dehydrogenase (EC 1.1.1.22) were obtained in space groups P622 and P4 3 2 1 2 and diffracted to 2.4 and 3.4 Å resolution, respectively. Gellan gum, a commercial gelling agent produced by Sphingomonas elodea ATCC 31461, is a high-value microbial exopolysaccharide. UDP-glucose dehydrogenase (UGD; EC 1.1.1.22) is responsible for the NAD-dependent twofold oxidation of UDP-glucose to UDP-glucuronic acid, one of the key components for gellan biosynthesis. S. elodea ATCC 31461 UGD, termed UgdG, was cloned, expressed, purified and crystallized in native and SeMet-derivatized forms in hexagonal and tetragonal space groups, respectively; the crystals diffracted X-rays to 2.40 and 3.40 Å resolution, respectively. Experimental phases were obtained for the tetragonal SeMet-derivatized crystal form by a single-wavelength anomalous dispersion experiment. This structure was successfully used as a molecular-replacement probe for the hexagonal crystal form of the native protein

  16. Myelination in the absence of UDP-galactose:ceramide galactosyl-transferase and fatty acid 2 -hydroxylase

    Directory of Open Access Journals (Sweden)

    Gieselmann Volkmar

    2011-03-01

    Full Text Available Abstract Background The sphingolipids galactosylceramide (GalCer and sulfatide are major myelin components and are thought to play important roles in myelin function. The importance of GalCer and sulfatide has been validated using UDP-galactose:ceramide galactosyltransferase-deficient (Cgt-/- mice, which are impaired in myelin maintenance. These mice, however, are still able to form compact myelin. Loss of GalCer and sulfatide in these mice is accompanied by up-regulation of 2-hydroxylated fatty acid containing (HFA-glucosylceramide in myelin. This was interpreted as a partial compensation of the loss of HFA-GalCer, which may prevent a more severe myelin phenotype. In order to test this hypothesis, we have generated Cgt-/- mice with an additional deletion of the fatty acid 2-hydroxylase (Fa2h gene. Results Fa2h-/-/Cgt-/- double-deficient mice lack sulfatide, GalCer, and in addition HFA-GlcCer and sphingomyelin. Interestingly, compared to Cgt-/- mice the amount of GlcCer in CNS myelin was strongly reduced in Fa2h-/-/Cgt-/- mice by more than 80%. This was accompanied by a significant increase in sphingomyelin, which was the predominant sphingolipid in Fa2h-/-/Cgt-/- mice. Despite these significant changes in myelin sphingolipids, compact myelin was formed in Fa2h-/-/Cgt-/- mice, and g-ratios of myelinated axons in the spinal cord of 4-week-old Fa2h-/-/Cgt-/- mice did not differ significantly from that of Cgt-/- mice, and there was no obvious phenotypic difference between Fa2h-/-/Cgt-/- and Cgt-/- mice Conclusions These data show that compact myelin can be formed with non-hydroxylated sphingomyelin as the predominant sphingolipid and suggest that the presence of HFA-GlcCer and HFA-sphingomyelin in Cgt-/- mice does not functionally compensate the loss of HFA-GalCer.

  17. Bioactivation of carboxylic acid compounds by UDP-Glucuronosyltransferases to DNA-damaging intermediates: role of glycoxidation and oxidative stress in genotoxicity.

    Science.gov (United States)

    Sallustio, Benedetta C; Degraaf, Yvette C; Weekley, Josephine S; Burcham, Philip C

    2006-05-01

    Nonenzymatic modification of proteins by acyl glucuronides is well documented; however, little is known about their potential to damage DNA. We have previously reported that clofibric acid undergoes glucuronidation-dependent bioactivation to DNA-damaging species in cultured mouse hepatocytes. The aim of this study was to investigate the mechanisms underlying such DNA damage, and to screen chemically diverse carboxylic acid drugs for their DNA-damaging potential in glucuronidation proficient murine hepatocytes. Cells were incubated with each aglycone for 18 h, followed by assessment of compound cytotoxicity using the MTT assay and evaluation of DNA damage using the Comet assay. Relative cytotoxic potencies were ketoprofen > diclofenac, benoxaprofen, nafenopin > gemfibrozil, probenecid > bezafibrate > clofibric acid. At a noncytotoxic (0.1 mM) concentration, only benoxaprofen, nafenopin, clofibric acid, and probenecid significantly increased Comet moments (P Clofibric acid and probenecid exhibited the greatest DNA-damaging potency, producing significant DNA damage at 0.01 mM concentrations. The two drugs produced maximal increases in Comet moment of 4.51 x and 2.57 x control, respectively. The glucuronidation inhibitor borneol (1 mM) abolished the induction of DNA damage by 0.5 mM concentrations of clofibric acid and probenecid. In an in vitro cell-free system, clofibric acid glucuronide was 10 x more potent than glucuronic acid in causing DNA strand-nicking, although both compounds showed similar rates of autoxidation to generate hydroxyl radicals. In cultured hepatocytes, the glycation inhibitor, aminoguanidine, and the iron chelator, desferrioxamine mesylate, inhibited DNA damage by clofibric acid, whereas the free radical scavengers Trolox and butylated hydroxytoluene, and the superoxide dismutase mimetic bis-3,5-diisopropylsalicylate had no effect. In conclusion, clinically relevant concentrations of two structurally unrelated carboxylic acids, probenecid and

  18. Molecular Structure of WlbB, a Bacterial N-Acetyltransferase Involved in the Biosynthesis of 2,3-Diacetamido-2,3-dideoxy-d-mannuronic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Thoden, James B.; Holden, Hazel M. (UW)

    2010-09-08

    The pathogenic bacteria Pseudomonas aeruginosa and Bordetella pertussis contain in their outer membranes the rare sugar 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid. Five enzymes are required for the biosynthesis of this sugar starting from UDP-N-acetylglucosamine. One of these, referred to as WlbB, is an N-acetyltransferase that converts UDP-2-acetamido-3-amino-2,3-dideoxy-D-glucuronic acid (UDP-GlcNAc3NA) to UDP-2,3-diacetamido-2,3-dideoxy-D-glucuronic acid (UDP-GlcNAc3NAcA). Here we report the three-dimensional structure of WlbB from Bordetella petrii. For this analysis, two ternary structures were determined to 1.43 {angstrom} resolution: one in which the protein was complexed with acetyl-CoA and UDP and the second in which the protein contained bound CoA and UDP-GlcNAc3NA. WlbB adopts a trimeric quaternary structure and belongs to the L{beta}H superfamily of N-acyltransferases. Each subunit contains 27 {beta}-strands, 23 of which form the canonical left-handed {beta}-helix. There are only two hydrogen bonds that occur between the protein and the GlcNAc3NA moiety, one between O{sup {delta}1} of Asn 84 and the sugar C-3{prime} amino group and the second between the backbone amide group of Arg 94 and the sugar C-5{prime} carboxylate. The sugar C-3{prime} amino group is ideally positioned in the active site to attack the si face of acetyl-CoA. Given that there are no protein side chains that can function as general bases within the GlcNAc3NA binding pocket, a reaction mechanism is proposed for WlbB whereby the sulfur of CoA ultimately functions as the proton acceptor required for catalysis.

  19. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

    Energy Technology Data Exchange (ETDEWEB)

    Thomassin, J.; Tephly, T.R. (Univ. of Iowa, Iowa City (USA))

    1990-09-01

    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

  20. UDP-glucuronosyltransferase-dependent bioactivation of clofibric acid to a DNA-damaging intermediate in mouse hepatocytes.

    Science.gov (United States)

    Ghaoui, Roula; Sallustio, Benedetta C; Burcham, Philip C; Fontaine, Frank R

    2003-05-06

    Glucuronidation of a number of carboxyl-containing drugs generates reactive acyl glucuronide metabolites. These electrophilic species alkylate cell proteins and may be implicated in the pathogenesis of a number of toxic syndromes seen in patients receiving the parent aglycones. Whether acyl glucuronides also attack nuclear DNA is unknown, although the acyl glucuronide formed from clofibric acid was recently found to decrease the transfection efficiency of phage DNA and generate strand breaks in plasmid DNA in vitro. To determine if such a DNA damage occurs within a cellular environment, the comet assay (i.e. single-cell gel electrophoresis) was used to detect DNA lesions in the nuclear genome of isolated mouse hepatocytes cultured with clofibric acid. Overnight exposure to 50 microM and higher concentrations of clofibric acid produced concentration-dependent increases in the comet areas of hepatocyte nuclei, with 1 mM clofibrate producing a 3.6-fold elevation over controls. These effects closely coincided with culture medium concentrations of the glucuronide metabolite formed from clofibric acid, 1-O-beta-clofibryl glucuronide. Consistent with a role for glucuronidation in the DNA damage observed, the glucuronidation inhibitor borneol diminished glucuronide formation from 100 microM clofibrate by 98% and returned comet areas to baseline levels. Collectively, these results suggest that the acyl glucuronide formed from clofibric acid is capable of migrating from its site of formation within the endoplasmic reticulum to generate strand nicks in nuclear DNA.

  1. Hepatic Metabolism of Sakuranetin and Its Modulating Effects on Cytochrome P450s and UDP-Glucuronosyltransferases

    Directory of Open Access Journals (Sweden)

    Hyesoo Jeong

    2018-06-01

    Full Text Available Sakuranetin (SKN, found in cherry trees and rice, is a flavanone with various pharmacological activities. It is biosynthesized from naringenin in rice or cherry trees, and the metabolism of SKN has been studied in non-human species. The present study aimed to investigate the metabolic pathways of SKN in human liver microsomes and identify the phase I and phase II metabolites, as well as evaluate the potential for drug–herb interactions through the modulation of drug metabolizing enzymes (DMEs. HPLC-DAD and HPLC-electrospray mass spectrometry were used to study the metabolic stability and identify the metabolites from human liver microsomes incubated with SKN. The potential of SKN to inhibit the DMEs was evaluated by monitoring the formation of a DME-specific product. The cytochrome P450 2B6 and 3A4-inductive effects were studied using promoter reporter assays in human hepatocarcinoma cells. The major pathways for SKN metabolism include B-ring hydroxylation, 5-O-demethylation, and conjugation with glutathione or glucuronic acid. The phase I metabolites were identified as naringenin and eriodictyol. SKN was found to be a UDP-glucuronosyltransferases (UGT 1A9 inhibitor, whereas it induced transactivation of the human pregnane X receptor-mediated cytochrome P450 (CYP 3A4 gene.

  2. UDP-Glucuronosyltransferase Expression in Mouse Liver Is Increased in Obesity- and Fasting-Induced Steatosis

    Science.gov (United States)

    Xu, Jialin; Kulkarni, Supriya R.; Li, Liya

    2012-01-01

    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lepob/ob (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance. PMID:22031624

  3. UDP-glucuronosyltransferase expression in mouse liver is increased in obesity- and fasting-induced steatosis.

    Science.gov (United States)

    Xu, Jialin; Kulkarni, Supriya R; Li, Liya; Slitt, Angela L

    2012-02-01

    UDP-glucuronosyltransferases (Ugt) catalyze phase II conjugation reactions with glucuronic acid, which enhances chemical polarity and the elimination from the body. Few studies have addressed whether Ugt expression and activity are affected by liver disease, such as steatosis. The purpose of this study was to determine whether steatosis induced by obesity or fasting could affect liver Ugt mRNA expression and activity. Male C57BL/6J and Lep(ob/ob) (ob/ob) mice were fed ad libitum or food was withheld for 24 h. In steatotic livers of ob/ob mice, Ugt1a1, -1a6, -1a9, -2a3, -3a1, and -3a2 mRNA expression increased. Fasting, which also induced steatosis, increased hepatic Ugt1a1, -1a6, -1a7, -1a9, -2b1, -2b5, -2a3, -3a1, and -3a2 mRNA expression in mouse liver. Likewise, acetaminophen glucuronidation increased by 47% in hepatic microsomes from ob/ob mice compared with that in C57BL/6J mice, but not after fasting. In both steatosis models, Ugt induction was accompanied by increased aryl hydrocarbon receptor, constitutive androstane receptor (CAR), peroxisome proliferator-activated receptor (PPAR)-α, pregnane X receptor, nuclear factor (erythroid-derived 2)-like 2 (Nrf2), and peroxisome proliferator-activated receptor-γ coactivator-1α mRNA expression. In addition, fasting increased CAR, PPAR, and Nrf2 binding activity. The work points to hepatic triglyceride concentrations corresponding with nuclear receptor and Ugt expression. The findings indicate that steatosis significantly alters hepatic Ugt expression and activity, which could have a significant impact on determining circulating hormone levels, drug efficacy, and environmental chemical clearance.

  4. UDP-galactose 4'-epimerase activities toward UDP-Gal and UDP-GalNAc play different roles in the development of Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Jennifer M I Daenzer

    Full Text Available In both humans and Drosophila melanogaster, UDP-galactose 4'-epimerase (GALE catalyzes two distinct reactions, interconverting UDP-galactose (UDP-gal and UDP-glucose (UDP-glc in the final step of the Leloir pathway of galactose metabolism, and also interconverting UDP-N-acetylgalactosamine (UDP-galNAc and UDP-N-acetylglucosamine (UDP-glcNAc. All four of these UDP-sugars serve as vital substrates for glycosylation in metazoans. Partial loss of GALE in humans results in the spectrum disorder epimerase deficiency galactosemia; partial loss of GALE in Drosophila melanogaster also results in galactose-sensitivity, and complete loss in Drosophila is embryonic lethal. However, whether these outcomes in both humans and flies result from loss of one GALE activity, the other, or both has remained unknown. To address this question, we uncoupled the two activities in a Drosophila model, effectively replacing the endogenous dGALE with prokaryotic transgenes, one of which (Escherichia coli GALE efficiently interconverts only UDP-gal/UDP-glc, and the other of which (Plesiomonas shigelloides wbgU efficiently interconverts only UDP-galNAc/UDP-glcNAc. Our results demonstrate that both UDP-gal and UDP-galNAc activities of dGALE are required for Drosophila survival, although distinct roles for each activity can be seen in specific windows of developmental time or in response to a galactose challenge. By extension, these data also suggest that both activities might play distinct and essential roles in humans.

  5. Crystal structure of product-bound complex of UDP-N-acetyl-D-mannosamine dehydrogenase from Pyrococcus horikoshii OT3

    Energy Technology Data Exchange (ETDEWEB)

    Pampa, K.J., E-mail: sagarikakj@gmail.com [Department of Studies in Microbiology, University of Mysore, Mysore 570 006 (India); Lokanath, N.K. [Department of Studies in Physics, University of Mysore, Mysore 570 006 (India); Girish, T.U. [Department of General Surgery, JSS Medical College and Hospital, JSS University, Mysore 570 015 (India); Kunishima, N. [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, Hyogo 679-5148 (Japan); Rai, V.R. [Department of Studies in Microbiology, University of Mysore, Mysore 570 006 (India)

    2014-10-24

    Highlights: • Determined the structure of UDP-D-ManNAcADH to a resolution of 1.55 Å. • First complex structure of PhUDP-D-ManNAcADH with UDP-D-ManMAcA. • The monomeric structure consists of three distinct domains. • Cys258 acting as catalytic nucleophilic and Lys204 acts as acid/base catalyst. • Oligomeric state plays an important role for the catalytic function. - Abstract: UDP-N-acetyl-D-mannosamine dehydrogenase (UDP-D-ManNAcDH) belongs to UDP-glucose/GDP-mannose dehydrogenase family and catalyzes Uridine-diphospho-N-acetyl-D-mannosamine (UDP-D-ManNAc) to Uridine-diphospho-N-acetyl-D-mannosaminuronic acid (UDP-D-ManNAcA) through twofold oxidation of NAD{sup +}. In order to reveal the structural features of the Pyrococcus horikoshii UDP-D-ManNAcADH, we have determined the crystal structure of the product-bound enzyme by X-ray diffraction to resolution of 1.55 Å. The protomer folds into three distinct domains; nucleotide binding domain (NBD), substrate binding domain (SBD) and oligomerization domain (OD, involved in the dimerization). The clear electron density of the UDP-D-ManNAcA is observed and the residues binding are identified for the first time. Crystal structures reveal a tight dimeric polymer chains with product-bound in all the structures. The catalytic residues Cys258 and Lys204 are conserved. The Cys258 acts as catalytic nucleophile and Lys204 as acid/base catalyst. The product is directly interacts with residues Arg211, Thr249, Arg244, Gly255, Arg289, Lys319 and Arg398. In addition, the structural parameters responsible for thermostability and oligomerization of the three dimensional structure are analyzed.

  6. Invariant amino acids in the Mur peptide synthetases of bacterial peptidoglycan synthesis and their modification by site-directed mutagenesis in the UDP-MurNAc:L-alanine ligase from Escherichia coli.

    Science.gov (United States)

    Bouhss, A; Mengin-Lecreulx, D; Blanot, D; van Heijenoort, J; Parquet, C

    1997-09-30

    The comparison of the amino acid sequences of 20 cytoplasmic peptidoglycan synthetases (MurC, MurD, MurE, MurF, and Mpl) from various bacterial organisms has allowed us to detect common invariants: seven amino acids and the ATP-binding consensus sequence GXXGKT/S all at the same position in the alignment. The Mur synthetases thus appeared as a well-defined class of closely functionally related proteins. The conservation of a constant backbone length between certain invariants suggested common structural motifs. Among the other enzymes catalyzing a peptide bond formation driven by ATP hydrolysis to ADP and Pi, only folylpoly-gamma-l-glutamate synthetases presented the same common conserved amino acid residues, except for the most N-terminal invariant D50. Site-directed mutageneses were carried out to replace the K130, E174, H199, N293, N296, R327, and D351 residues by alanine in the MurC protein from Escherichia coli taken as model. For this purpose, plasmid pAM1005 was used as template, MurC being highly overproduced in this genetic setting. Analysis of the Vmax values of the mutated proteins suggested that residues K130, E174, and D351 are essential for the catalytic process whereas residues H199, N293, N296, and R327 were not. Mutations K130A, H199A, N293A, N296A, and R327A led to important variations of the Km values for one or more substrates, thereby indicating that these residues are involved in the structure of the active site and suggesting that the binding order of the substrates could be ATP, UDP-MurNAc, and alanine. The various mutated murC plasmids were tested for their effects on the growth, cell morphology, and peptidoglycan cell content of a murC thermosensitive strain at 42 degrees C. The observed effects (complementation, altered morphology, and reduced peptidoglycan content) paralleled more or less the decreased values of the MurC activity of each mutant.

  7. Crystal structure of product-bound complex of UDP-N-acetyl-d-mannosamine dehydrogenase from Pyrococcus horikoshii OT3.

    Science.gov (United States)

    Pampa, K J; Lokanath, N K; Girish, T U; Kunishima, N; Rai, V R

    2014-10-24

    UDP-N-acetyl-d-mannosamine dehydrogenase (UDP-d-ManNAcDH) belongs to UDP-glucose/GDP-mannose dehydrogenase family and catalyzes Uridine-diphospho-N-acetyl-d-mannosamine (UDP-d-ManNAc) to Uridine-diphospho-N-acetyl-d-mannosaminuronic acid (UDP-d-ManNAcA) through twofold oxidation of NAD(+). In order to reveal the structural features of the Pyrococcus horikoshii UDP-d-ManNAcADH, we have determined the crystal structure of the product-bound enzyme by X-ray diffraction to resolution of 1.55Å. The protomer folds into three distinct domains; nucleotide binding domain (NBD), substrate binding domain (SBD) and oligomerization domain (OD, involved in the dimerization). The clear electron density of the UDP-d-ManNAcA is observed and the residues binding are identified for the first time. Crystal structures reveal a tight dimeric polymer chains with product-bound in all the structures. The catalytic residues Cys258 and Lys204 are conserved. The Cys258 acts as catalytic nucleophile and Lys204 as acid/base catalyst. The product is directly interacts with residues Arg211, Thr249, Arg244, Gly255, Arg289, Lys319 and Arg398. In addition, the structural parameters responsible for thermostability and oligomerization of the three dimensional structure are analyzed. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Association of the golgi UDP-galactose transporter with UDP-galactose: ceramide galactosyltransferase allows UDP-galactose import in the endoplasmic reticulum

    NARCIS (Netherlands)

    Sprong, H.; Degroote, S.; Nilsson, T.; Kawakita, M.; Ishida, N.; van der Sluijs, P.; van Meer, G.

    2003-01-01

    UDP-galactose reaches the Golgi lumen through the UDP-galactose transporter (UGT) and is used for the galactosylation of proteins and lipids. Ceramides and diglycerides are galactosylated within the endoplasmic reticulum by the UDP-galactose: ceramide galactosyltransferase. It is not known how

  9. The UDP glucuronosyltransferase gene superfamily: suggested nomenclature based on evolutionary divergence

    NARCIS (Netherlands)

    Burchell, B.; Nebert, D. W.; Nelson, D. R.; Bock, K. W.; Iyanagi, T.; Jansen, P. L.; Lancet, D.; Mulder, G. J.; Chowdhury, J. R.; Siest, G.

    1991-01-01

    A nomenclature system for the UDP glucuronosyltransferase superfamily is proposed, based on divergent evolution of the genes. A total of 26 distinct cDNAs in five mammalian species have been sequenced to date. Comparison of the deduced amino acid sequences leads to the definition of two families and

  10. Molecular cloning and tissue-specific transcriptional regulation of the first peroxidase family member, Udp1, in stinging nettle (Urtica dioica).

    Science.gov (United States)

    Douroupi, Triantafyllia G; Papassideri, Issidora S; Stravopodis, Dimitrios J; Margaritis, Lukas H

    2005-12-05

    A full-length cDNA clone, designated Udp1, was isolated from Urtica dioica (stinging nettle), using a polymerase chain reaction based strategy. The putative Udp1 protein is characterized by a cleavable N-terminal signal sequence, likely responsible for the rough endoplasmic reticulum entry and a 310 amino acids mature protein, containing all the important residues, which are evolutionary conserved among different members of the plant peroxidase family. A unique structural feature of the Udp1 peroxidase is defined into the short carboxyl-terminal extension, which could be associated with the vacuolar targeting process. Udp1 peroxidase is differentially regulated at the transcriptional level and is specifically expressed in the roots. Interestingly, wounding and ultraviolet radiation stress cause an ectopic induction of the Udp1 gene expression in the aerial parts of the plant. A genomic DNA fragment encoding the Udp1 peroxidase was also cloned and fully sequenced, revealing a structural organization of three exons and two introns. The phylogenetic relationships of the Udp1 protein to the Arabidopsis thaliana peroxidase family members were also examined and, in combination with the homology modelling approach, dictated the presence of distinct structural elements, which could be specifically involved in the determination of substrate recognition and subcellular localization of the Udp1 peroxidase.

  11. Endogenous acceptors for polyuronide biosynthesis in Mucor rouxii

    International Nuclear Information System (INIS)

    Carreon, A.F.; Balcazar, R.

    1984-01-01

    Cell walls of Mucor rouxii contain relatively high amounts of acidic polymers of D-glucuronic acid. Two types of polyuronides have been isolated from cell walls of M. rouxii: mucoric acid and mucoran. Mucoran isolated from yeast cell walls is a heteropolysaccharide containing D-mannose, D-fructose, D-galactose, and D-glucose, besides D-glucuronic acid. On the other hand, mucoric acid, from sporangiophore walls is a homopolymer of D-glucuronic acid. Glucuronosyl transferase, the enzyme which catalyzes the transfer of glucuronic acid from UDP-glucuronic acid to acidic polymers, has been demonstrated using crude membrane fractions from M. rouxii

  12. Substrate Specificity and Inhibitor Sensitivity of Plant UDP-Sugar Producing Pyrophosphorylases

    Directory of Open Access Journals (Sweden)

    Daniel Decker

    2017-09-01

    Full Text Available UDP-sugars are essential precursors for glycosylation reactions producing cell wall polysaccharides, sucrose, glycoproteins, glycolipids, etc. Primary mechanisms of UDP sugar formation involve the action of at least three distinct pyrophosphorylases using UTP and sugar-1-P as substrates. Here, substrate specificities of barley and Arabidopsis (two isozymes UDP-glucose pyrophosphorylases (UGPase, Arabidopsis UDP-sugar pyrophosphorylase (USPase and Arabidopsis UDP-N-acetyl glucosamine pyrophosphorylase2 (UAGPase2 were investigated using a range of sugar-1-phosphates and nucleoside-triphosphates as substrates. Whereas all the enzymes preferentially used UTP as nucleotide donor, they differed in their specificity for sugar-1-P. UGPases had high activity with D-Glc-1-P, but could also react with Fru-1-P and Fru-2-P (Km values over 10 mM. Contrary to an earlier report, their activity with Gal-1-P was extremely low. USPase reacted with a range of sugar-1-phosphates, including D-Glc-1-P, D-Gal-1-P, D-GalA-1-P (Km of 1.3 mM, β-L-Ara-1-P and α-D-Fuc-1-P (Km of 3.4 mM, but not β-L-Fuc-1-P. In contrast, UAGPase2 reacted only with D-GlcNAc-1-P, D-GalNAc-1-P (Km of 1 mM and, to some extent, D-Glc-1-P (Km of 3.2 mM. Generally, different conformations/substituents at C2, C4, and C5 of the pyranose ring of a sugar were crucial determinants of substrate specificity of a given pyrophosphorylase. Homology models of UDP-sugar binding to UGPase, USPase and UAGPase2 revealed more common amino acids for UDP binding than for sugar binding, reflecting differences in substrate specificity of these proteins. UAGPase2 was inhibited by a salicylate derivative that was earlier shown to affect UGPase and USPase activities, consistent with a common structural architecture of the three pyrophosphorylases. The results are discussed with respect to the role of the pyrophosphorylases in sugar activation for glycosylated end-products.

  13. Glucuronic Acid Derivatives in Enzymatic Biomass Degradation: Synthesis and Evaluation of Enzymatic Activity

    DEFF Research Database (Denmark)

    d'Errico, Clotilde

    An essential tool for biotechnology companies in enzyme development for biomass delignification is the access to well-defined model substrates. A deeper understanding of the enzymes substrate specificity can be used to address and optimize enzyme mixtures towards natural, complex substrates. Hence...

  14. Variability of human hepatic UDP-glucuronosyltransferase activity

    NARCIS (Netherlands)

    Little, JM; Lester, R; Kuipers, F; Vonk, R; Mackenzie, PI; Drake, RR; Frame, L; Radominska-Pandya, A

    1999-01-01

    The availability of a unique series of liver samples from human subjects, both control patients (9) and those with liver disease (6; biliary atresia (2), retransplant, chronic tyrosinemia type I, tyrosinemia, Wilson's disease) allowed us to characterize human hepatic UDP-glucuronosyltransferases

  15. Biochemical characterization of an inhibitor of Escherichia coli UDP-N-acetylmuramyl-l-alanine ligase.

    Science.gov (United States)

    Ehmann, David E; Demeritt, Julie E; Hull, Kenneth G; Fisher, Stewart L

    2004-05-06

    UDP-N-acetylmuramyl-l-alanine ligase (MurC) is an essential bacterial enzyme involved in peptidoglycan biosynthesis and a target for the discovery of novel antibacterial agents. As a result of a high-throughput screen (HTS) against a chemical library for inhibitors of MurC, a series of benzofuran acyl-sulfonamides was identified as potential leads. One of these compounds, Compound A, inhibited Escherichia coli MurC with an IC(50) of 2.3 microM. Compound A exhibited time-dependent, partially reversible inhibition of E. coli MurC. Kinetic studies revealed a mode of inhibition consistent with the compound acting competitively with the MurC substrates ATP and UDP-N-acetyl-muramic acid (UNAM) with a K(i) of 4.5 microM against ATP and 6.3 microM against UNAM. Fluorescence binding experiments yielded a K(d) of 3.1 microM for the compound binding to MurC. Compound A also exhibited high-affinity binding to bovine serum albumin (BSA) as evidenced by a severe reduction in MurC inhibition upon addition of BSA. This finding is consistent with the high lipophilicity of the compound. Advancement of this compound series for further drug development will require reduction of albumin binding.

  16. Improving UDP/IP Transmission Without Increasing Congestion

    Science.gov (United States)

    Burleigh, Scott

    2006-01-01

    Datagram Retransmission (DGR) is a computer program that, within certain limits, ensures the reception of each datagram transmitted under the User Datagram Protocol/Internet Protocol. [User Datagram Protocol (UDP) is considered unreliable because it does not involve a reliability-ensuring connection-initiation dialogue between sender and receiver. UDP is well suited to issuing of many small messages to many different receivers.] Unlike prior software for ensuring reception of UDP datagrams, DGR does not contribute to network congestion by retransmitting data more frequently as an ever-increasing number of messages and acknowledgements is lost. Instead, DGR does just the opposite: DGR includes an adaptive timeout-interval- computing component that provides maximum opportunity for reception of acknowledgements, minimizing retransmission. By monitoring changes in the rate at which message-transmission transactions are completed, DGR detects changes in the level of congestion and responds by imposing varying degrees of delay on the transmission of new messages. In addition, DGR maximizes throughput by not waiting for acknowledgement of a message before sending the next message. All DGR communication is asynchronous, to maximize efficient utilization of network connections. DGR manages multiple concurrent datagram transmission and acknowledgement conversations.

  17. Bacterial origin of a diverse family of UDP-glycosyltransferase genes in the Tetranychus urticae genome

    NARCIS (Netherlands)

    Ahn, S.J.; Dermauw, W.; Wybouw, N.; Heckel, D.G.; Van Leeuwen, T.

    2014-01-01

    UDP-glycosyltransferases (UGTs) catalyze the conjugation of a variety of small lipophilic molecules with uridine diphosphate (UDP) sugars, altering them into more water-soluble metabolites. Thereby, UGTs play an important role in the detoxification of xenobiotics and in the regulation of

  18. UDP-galactose: ceramide galactosyltransferase is a class I integral membrane protein of the endoplasmic reticulum

    NARCIS (Netherlands)

    Sprong, H.; Kruithof, B.; Leijendekker, R.L.; Slot, J.W.; van Meer, G.; van der Sluijs, P.

    1998-01-01

    UDP-galactose:ceramide galactosyltransferase (CGalT) transfers UDP-galactose to ceramide to form the glycosphingolipid galactosylceramide. Galactosylceramide is the major constituent of myelin and is also highly enriched in many epithelial cells, where it is thought to play an important role in

  19. UDP-N-acetyl-α-D-glucosamine as acceptor substrate of β-1,4-galactosyltransferase : Enzymatic synthesis of UDP-N-acetyllactosamine

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Elling, L.; Zervosen, A.; Gutiérrez Gallego, R.; Nieder, V.; Malissard, M.; Berger, E.G.; Kamerling, J.P.

    1999-01-01

    The capacity of UDP-N-acetyl-α-D-glucosamine (UDP-GlcNAc) as an in vitro acceptor substrate for β-1,4-galactosyltransferase (β4GalT1, EC 2.4.1.38) from human and bovine milk and for recombinant human β4GalT1, expressed in Saccharomyces cerevisiae, was evaluated. It turned out that each of the

  20. Analysis of CBRP for UDP and TCP Traffic-Classes to measure throughput in MANETs

    Directory of Open Access Journals (Sweden)

    Hardeep Singh Rayait

    2013-01-01

    Full Text Available In this paper, we analyse the throughput of both TCP and UDP traffic classes for cluster based routing protocol for mobile ad hoc network. It uses clustering structure to improve throughput , decrease average end-to-end delay and improve the average packet delivery ratio. We simulate our routing protocol for nodes running the IEEE802.11 MAC for analysis of throughput for both UDP and TCP traffic classes. The application layer protocol used for UDP is CBR and for TCP is FTP.

  1. A homogeneous, high-throughput-compatible, fluorescence intensity-based assay for UDP-N-acetylenolpyruvylglucosamine reductase (MurB) with nanomolar product detection.

    Science.gov (United States)

    Shapiro, Adam B; Livchak, Stephania; Gao, Ning; Whiteaker, James; Thresher, Jason; Jahić, Haris; Huang, Jian; Gu, Rong-Fang

    2012-03-01

    A novel assay for the NADPH-dependent bacterial enzyme UDP-N-acetylenolpyruvylglucosamine reductase (MurB) is described that has nanomolar sensitivity for product formation and is suitable for high-throughput applications. MurB catalyzes an essential cytoplasmic step in the synthesis of peptidoglycan for the bacterial cell wall, reduction of UDP-N-acetylenolpyruvylglucosamine to UDP-N-acetylmuramic acid (UNAM). Interruption of this biosynthetic pathway leads to cell death, making MurB an attractive target for antibacterial drug discovery. In the new assay, the UNAM product of the MurB reaction is ligated to L-alanine by the next enzyme in the peptidoglycan biosynthesis pathway, MurC, resulting in hydrolysis of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). The ADP is detected with nanomolar sensitivity by converting it to oligomeric RNA with polynucleotide phosphorylase and detecting the oligomeric RNA with a fluorescent dye. The product sensitivity of the new assay is 1000-fold greater than that of the standard assay that follows the absorbance decrease resulting from the conversion of NADPH to NADP(+). This sensitivity allows inhibitor screening to be performed at the low substrate concentrations needed to make the assay sensitive to competitive inhibition of MurB.

  2. Immunoaffinity purification and reconstitution of the human bilirubin/phenol UDP-glucuronosyltransferase family

    NARCIS (Netherlands)

    Seppen, J.; Jansen, P. L.; Oude Elferink, R. P.

    1995-01-01

    When membrane proteins are solubilized and subjected to purification procedures, the loss of lipids surrounding the protein often results in irreversible inactivation. We describe a procedure for the immunoaffinity purification of the membrane protein UDP-glucuronosyltransferase from human liver.

  3. IMMUNOAFFINITY PURIFICATION AND RECONSTITUTION OF THE HUMAN BILIRUBIN PHENOL UDP-GLUCURONOSYLTRANSFERASE FAMILY

    NARCIS (Netherlands)

    SEPPEN, J; JANSEN, PLM; ELFERINK, RPJO

    When membrane proteins are solubilized and subjected to purification procedures, the loss of lipids surrounding the protein often results in irreversible inactivation. We describe a procedure for the immunoaffinity purification of the membrane protein UDP-glucuronosyltransferase from human liver.

  4. UDP-glucose pyrophosphorylase from tubers of Jerusalem artichoke (Helianthus tuberosus L.)

    International Nuclear Information System (INIS)

    Otozai, Kiyotaka; Taniguchi, Hajime; Nakamura, Michinori

    1973-01-01

    UDP-glucose pyrophosphorylase of Jerusalem artichoke tubers was purified 90-fold over the crude extract. The purified enzyme preparation absolutely required magnesium ions for activity. Cobalt ions were 60% as effective as magnesium ions; other divalent cations including manganese showed little or no effect. This enzyme had a pH optimum of 8.5 and a temperature optimum of 40 deg C. ATP and UDP inhibited the activity of this enzyme in both forward and backward directions. Km values for UDP-glucose, inorganic pyrophosphate, glucose-1-phosphate - 14 C and UTP were determined to be 4.45 x 10 -4 , 2.33 x 10 -4 , 9.38 x 10 -4 and 2.98 x 10 -4 M, respectively. These results are discussed in comparison with those of UDP-glucose pyrophosphorylases isolated from other plants. (author)

  5. Sistem Pencegahan UDP DNS Flood Dengan Filter Firewall Pada Router Mikrotik

    Directory of Open Access Journals (Sweden)

    Doni Aprilianto

    2017-05-01

    Full Text Available Serangan terhadap server jaringan dapat terjadi kapan saja,  jenis serangan yang dapat menyebabkan efek yang signifikan pada sebuah router adalah UDP-Flooding. UDP (User Datagram Protocol-Flooding adalah jenis serangan yang memanfaatkan protokol UDP dengan mengurangi sambungan (connectionless untuk menyerang target. Dalam analisis ini menggunakan metode penelitian deskriptif untuk memperoleh data secara langsung dengan melakukan teknik flooding serta teknik pencegahannya terhadap server yang telah dirancang. Dengan menggunakan Filter Rules yang telah dibuat, packet yang melalui port DNS selain IP Address yang telah di allow jika mencoba melakukan request atau flood DNS ke IP Public ISP pada router mikrotik, maka packet tersebut akan langsung di drop oleh pengaturan rules tersebut. kesimpulan yang dapat diambil yaitu penerapan filter firewall pada router mikrotik dapat mengurangi jumlah paket data UDP yang dikirimkan oleh attacker melalui port DNS sebanyak 60% dari jumlah paket yang masuk jika tanpa firewall.

  6. Identification of UDP glucosyltransferases from the aluminum-resistant tree Eucalyptus camaldulensis forming β-glucogallin, the precursor of hydrolyzable tannins.

    Science.gov (United States)

    Tahara, Ko; Nishiguchi, Mitsuru; Frolov, Andrej; Mittasch, Juliane; Milkowski, Carsten

    2018-08-01

    In the highly aluminum-resistant tree Eucalyptus camaldulensis, hydrolyzable tannins are proposed to play a role in internal detoxification of aluminum, which is a major factor inhibiting plant growth on acid soils. To understand and modulate the molecular mechanisms of aluminum detoxification by hydrolyzable tannins, the biosynthetic genes need to be identified. In this study, we identified and characterized genes encoding UDP-glucose:gallate glucosyltransferase, which catalyzes the formation of 1-O-galloyl-β-d-glucose (β-glucogallin), the precursor of hydrolyzable tannins. By homology-based cloning, seven full-length candidate cDNAs were isolated from E. camaldulensis and expressed in Escherichia coli as recombinant N-terminal His-tagged proteins. Phylogenetic analysis classified four of these as UDP glycosyltransferase (UGT) 84A subfamily proteins (UGT84A25a, -b, UGT84A26a, -b) and the other three as UGT84J subfamily proteins (UGT84J3, -4, -5). In vitro enzyme assays showed that the UGT84A proteins catalyzed esterification of UDP-glucose and gallic acid to form 1-O-galloyl-β-d-glucose, whereas the UGT84J proteins were inactive. Further analyses with UGT84A25a and -26a indicated that they also formed 1-O-glucose esters of other structurally related hydroxybenzoic and hydroxycinnamic acids with a preference for hydroxybenzoic acids. The UGT84A genes were expressed in leaves, stems, and roots of E. camaldulensis, regardless of aluminum stress. Taken together, our results suggest that the UGT84A subfamily enzymes of E. camaldulensis are responsible for constitutive production of 1-O-galloyl-β-d-glucose, which is the first step of hydrolyzable tannin biosynthesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Rv3634c from Mycobacterium tuberculosis H37Rv encodes an enzyme with UDP-Gal/Glc and UDP-GalNAc 4-epimerase activities.

    Directory of Open Access Journals (Sweden)

    Peehu Pardeshi

    Full Text Available A bioinformatics study revealed that Mycobacterium tuberculosis H37Rv (Mtb contains sequence homologs of Campylobacter jejuni protein glycosylation enzymes. The ORF Rv3634c from Mtb was identified as a sequence homolog of C. jejuni UDP-Gal/GalNAc 4-epimerase. This study reports the cloning of Rv3634c and its expression as an N-terminal His-tagged protein. The recombinant protein was shown to have UDP-Gal/Glc 4-epimerase activity by GOD-POD assay and by reverse phase HPLC. This enzyme was shown to have UDP-GalNAc 4-epimerase activity also. Residues Ser121, Tyr146 and Lys150 were shown by site-directed mutagenesis to be important for enzyme activity. Mutation of Ser121 and Tyr146 to Ala and Phe, respectively, led to complete loss of activity whereas mutation of Lys150 to Arg led to partial loss of activity. There were no gross changes in the secondary structures of any of these three mutants. These results suggest that Ser121 and Tyr146 are essential for epimerase activity of Rv3634c. UDP-Gal/Glc 4-epimerases from other organisms also have a catalytic triad consisting of Ser, Tyr and Lys. The triad carries out proton transfer from nucleotide sugar to NAD+ and back, thus effecting the epimerization of the substrate. Addition of NAD+ to Lys150 significantly abrogates the loss of activity, suggesting that, as in other epimerases, NAD+ is associated with Rv3634c.

  8. Identification and partial characterization of a novel UDP-N-acetylenolpyruvoylglucosamine reductase/UDP-N-acetylmuramate:L-alanine ligase fusion enzyme from Verrucomicrobium spinosum DSM 4136T

    Directory of Open Access Journals (Sweden)

    Kubra F Naqvi

    2016-03-01

    Full Text Available The enzymes involved in synthesizing the bacterial cell wall are attractive targets for the design of antibacterial compounds, since this pathway is essential for bacteria and is absent in animals, particularly humans. A survey of the genome of a bacterium that belongs to the phylum Verrucomicrobia, the closest free-living relative to bacteria from the Chlamydiales phylum, shows genetic evidence that Verrucomicrobium spinosum possesses a novel fusion open reading frame (ORF annotated by the locus tag (VspiD_010100018130. The ORF, which is predicted to encode the enzymes UDP-N-acetylenolpyruvoylglucosamine reductase (MurB and UDP-N-acetylmuramate:L-alanine ligase (MurC that are involved in the cytoplasmic steps of peptidoglycan biosynthesis, was cloned. In vivo analyses using functional complementation showed that the fusion gene was able to complement E. coli murB and murC temperature sensitive mutants. The purified recombinant fusion enzyme (MurB/CVs was shown to be endowed with UDP-N-acetylmuramate:L-alanine ligase activity. In vitro analyses demonstrated that the latter enzyme had a pH optimum of 9.0, a magnesium optimum of 10 mM and a temperature optimum of 44-46 oC. Its apparent Km values for ATP, UDP-MurNAc and L-alanine were 470, 90 and 25 µM, respectively. However, all attempts to demonstrate an in vitro UDP-N-acetylenolpyruvoylglucosamine reductase (MurB activity were unsuccessful. Lastly, Hidden Markov Model-based similarity search and phylogenetic analysis revealed that this fusion enzyme could only be identified in specific lineages within the Verrucomicrobia phylum.

  9. Identification and Partial Characterization of a Novel UDP-N-Acetylenolpyruvoylglucosamine Reductase/UDP-N-Acetylmuramate:l-Alanine Ligase Fusion Enzyme from Verrucomicrobium spinosum DSM 4136(T).

    Science.gov (United States)

    Naqvi, Kubra F; Patin, Delphine; Wheatley, Matthew S; Savka, Michael A; Dobson, Renwick C J; Gan, Han Ming; Barreteau, Hélène; Blanot, Didier; Mengin-Lecreulx, Dominique; Hudson, André O

    2016-01-01

    The enzymes involved in synthesizing the bacterial cell wall are attractive targets for the design of antibacterial compounds, since this pathway is essential for bacteria and is absent in animals, particularly humans. A survey of the genome of a bacterium that belongs to the phylum Verrucomicrobia, the closest free-living relative to bacteria from the Chlamydiales phylum, shows genetic evidence that Verrucomicrobium spinosum possesses a novel fusion open reading frame (ORF) annotated by the locus tag (VspiD_010100018130). The ORF, which is predicted to encode the enzymes UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and UDP-N-acetylmuramate:l-alanine ligase (MurC) that are involved in the cytoplasmic steps of peptidoglycan biosynthesis, was cloned. In vivo analyses using functional complementation showed that the fusion gene was able to complement Escherichia coli murB and murC temperature sensitive mutants. The purified recombinant fusion enzyme (MurB/C Vs ) was shown to be endowed with UDP-N-acetylmuramate:l-alanine ligase activity. In vitro analyses demonstrated that the latter enzyme had a pH optimum of 9.0, a magnesium optimum of 10 mM and a temperature optimum of 44-46°C. Its apparent K m values for ATP, UDP-MurNAc, and l-alanine were 470, 90, and 25 μM, respectively. However, all attempts to demonstrate an in vitro UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) activity were unsuccessful. Lastly, Hidden Markov Model-based similarity search and phylogenetic analysis revealed that this fusion enzyme could only be identified in specific lineages within the Verrucomicrobia phylum.

  10. Identification and Partial Characterization of a Novel UDP-N-Acetylenolpyruvoylglucosamine Reductase/UDP-N-Acetylmuramate:l-Alanine Ligase Fusion Enzyme from Verrucomicrobium spinosum DSM 4136T

    Science.gov (United States)

    Naqvi, Kubra F.; Patin, Delphine; Wheatley, Matthew S.; Savka, Michael A.; Dobson, Renwick C. J.; Gan, Han Ming; Barreteau, Hélène; Blanot, Didier; Mengin-Lecreulx, Dominique; Hudson, André O.

    2016-01-01

    The enzymes involved in synthesizing the bacterial cell wall are attractive targets for the design of antibacterial compounds, since this pathway is essential for bacteria and is absent in animals, particularly humans. A survey of the genome of a bacterium that belongs to the phylum Verrucomicrobia, the closest free-living relative to bacteria from the Chlamydiales phylum, shows genetic evidence that Verrucomicrobium spinosum possesses a novel fusion open reading frame (ORF) annotated by the locus tag (VspiD_010100018130). The ORF, which is predicted to encode the enzymes UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) and UDP-N-acetylmuramate:l-alanine ligase (MurC) that are involved in the cytoplasmic steps of peptidoglycan biosynthesis, was cloned. In vivo analyses using functional complementation showed that the fusion gene was able to complement Escherichia coli murB and murC temperature sensitive mutants. The purified recombinant fusion enzyme (MurB/CVs) was shown to be endowed with UDP-N-acetylmuramate:l-alanine ligase activity. In vitro analyses demonstrated that the latter enzyme had a pH optimum of 9.0, a magnesium optimum of 10 mM and a temperature optimum of 44–46°C. Its apparent Km values for ATP, UDP-MurNAc, and l-alanine were 470, 90, and 25 μM, respectively. However, all attempts to demonstrate an in vitro UDP-N-acetylenolpyruvoylglucosamine reductase (MurB) activity were unsuccessful. Lastly, Hidden Markov Model-based similarity search and phylogenetic analysis revealed that this fusion enzyme could only be identified in specific lineages within the Verrucomicrobia phylum. PMID:27047475

  11. Lightweight UDP Pervasive Protocol in Smart Home Environment Based on Labview

    Science.gov (United States)

    Kurniawan, Wijaya; Hannats Hanafi Ichsan, Mochammad; Rizqika Akbar, Sabriansyah; Arwani, Issa

    2017-04-01

    TCP (Transmission Control Protocol) technology in a reliable environment was not a problem, but not in an environment where the entire Smart Home network connected locally. Currently employing pervasive protocols using TCP technology, when data transmission is sent, it would be slower because they have to perform handshaking process in advance and could not broadcast the data. On smart home environment, it does not need large size and complex data transmission between monitoring site and monitoring center required in Smart home strain monitoring system. UDP (User Datagram Protocol) technology is quick and simple on data transmission process. UDP can broadcast messages because the UDP did not require handshaking and with more efficient memory usage. LabVIEW is a programming language software for processing and visualization of data in the field of data acquisition. This paper proposes to examine Pervasive UDP protocol implementations in smart home environment based on LabVIEW. UDP coded in LabVIEW and experiments were performed on a PC and can work properly.

  12. Novel insights into E. coli's hexuronate metabolism: KduI facilitates the conversion of galacturonate and glucuronate under osmotic stress conditions.

    Directory of Open Access Journals (Sweden)

    Monique Rothe

    Full Text Available Using a gnotobiotic mouse model, we previously observed the upregulation of 2-deoxy-D-gluconate 3-dehydrogenase (KduD in intestinal E. coli of mice fed a lactose-rich diet and the downregulation of this enzyme and of 5-keto 4-deoxyuronate isomerase (KduI on a casein-rich diet. The present study aimed to define the role of the so far poorly characterized E. coli proteins KduD and KduI in vitro. Galacturonate and glucuronate induced kduD and kduI gene expression 3-fold and 7 to 11-fold, respectively, under aerobic conditions as well as 9 to 20-fold and 19 to 54-fold, respectively, under anaerobic conditions. KduI facilitated the breakdown of these hexuronates. In E. coli, galacturonate and glucuronate are normally degraded by UxaABC and UxuAB. However, osmotic stress represses the expression of the corresponding genes in an OxyR-dependent manner. When grown in the presence of galacturonate or glucuronate, kduID-deficient E. coli had a 30% to 80% lower maximal cell density and 1.5 to 2-fold longer doubling times under osmotic stress conditions than wild type E. coli. Growth on lactose promoted the intracellular formation of hexuronates, which possibly explain the induction of KduD on a lactose-rich diet. These results indicate a novel function of KduI and KduD in E. coli and demonstrate the crucial influence of osmotic stress on the gene expression of hexuronate degrading enzymes.

  13. Regulation of UDP glucuronosyltransferases in the gastrointestinal tract

    International Nuclear Information System (INIS)

    Gregory, Philip A.; Lewinsky, Rikke H.; Gardner-Stephen, Dione A.; Mackenzie, Peter I.

    2004-01-01

    The UDP glucuronosyltransferases (UGT) of the gastrointestinal (GI) tract have a crucial role in protection against the toxic effects of lipophilic chemicals in the environment. UGTs such as UGT1A7, UGT1A8, and UGT1A10 are exclusively expressed in gastrointestinal tissues, each with a unique tissue distribution pattern that is subject to interindividual variation. The factors regulating this tissue-specific expression and that contribute to variability are beginning to be elucidated. Studies on the UGT1A7, 1A8, 1A9, and 1A10 gene promoters in Caco-2 cells, an in vitro model of enterocytes of the gastrointestinal tract, have identified the caudal homeodomain transcription factor, Cdx2, as an important regulator of the UGT1A8 and 1A10 gene proximal promoters. This transcription factor is found exclusively in the small intestine and colon: it is absent in the gastric epithelium and the esophagus. Cdx2 regulates the UGT1A8 and 1A10 promoters in cooperation with hepatocyte nuclear factor 1α (HNF1α). It is noteworthy that UGT1A7 is not expressed in gastrointestinal tissue distal to the gastric mucosa and does not contain a Cdx2 binding site in its proximal promoter. Transcription factors, including Sp1, which differentially bind to the initiator regions of the UGT1A8, 1A9, and 1A10 promoters, also contribute to the differences in expression of these UGTs in Caco-2 cells. The identification of important regulatory regions of UGT genes expressed in the gastrointestinal tract, and the transcription factors that bind to these regions, will aid in the elucidation of factors that contribute to interindividual differences in gastrointestinal UGT expression. In turn, this will lead to further understanding of interindividual variation in the capacity of the GI tract to metabolize lipophilic chemicals and to act as a barrier to dietary toxins and orally administered drugs

  14. Structure of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC).

    Science.gov (United States)

    Deva, Taru; Baker, Edward N; Squire, Christopher J; Smith, Clyde A

    2006-12-01

    The bacterial cell wall provides essential protection from the external environment and confers strength and rigidity to counteract internal osmotic pressure. Without this layer the cell would be easily ruptured and it is for this reason that biosynthetic pathways leading to the formation of peptidoglycan have for many years been a prime target for effective antibiotics. Central to this pathway are four similar ligase enzymes which add peptide groups to glycan moieties. As part of a program to better understand the structure-function relationships in these four enzymes, the crystal structure of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC) has been determined to 2.6 A resolution. The structure was solved by multiwavelength anomalous diffraction methods from a single selenomethionine-substituted crystal and refined to a crystallographic R factor of 0.212 (R(free) = 0.259). The enzyme has a modular multi-domain structure very similar to those of other members of the mur family of ATP-dependent amide-bond ligases. Detailed comparison of these four enzymes shows that considerable conformational changes are possible. These changes, together with the recruitment of two different N-terminal domains, allow this family of enzymes to bind a substrate which is identical at one end and at the other has the growing peptide tail which will ultimately become part of the rigid bacterial cell wall. Comparison of the E. coli and Haemophilus influenzae structures and analysis of the sequences of known MurC enzymes indicate the presence of a ;dimerization' motif in almost 50% of the MurC enzymes and points to a highly conserved loop in domain 3 that may play a key role in amino-acid ligand specificity.

  15. Modulation of hyaluronan synthase activity in cellular membrane fractions

    OpenAIRE

    Vigetti, Davide; Genasetti, A; Karousou, Evgenia; Viola, Manuela; Clerici, M; Bartolini, B; Moretto, Paola; DE LUCA, Giancarlo; Hascall, Vc; Passi, Alberto

    2009-01-01

    Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in euk...

  16. Genome-Wide Identification and Expression Analysis of the UGlcAE Gene Family in Tomato

    OpenAIRE

    Xing Ding; Jinhua Li; Yu Pan; Yue Zhang; Lei Ni; Yaling Wang; Xingguo Zhang

    2018-01-01

    The UGlcAE has the capability of interconverting UDP-d-galacturonic acid and UDP-d-glucuronic acid, and UDP-d-galacturonic acid is an activated precursor for the synthesis of pectins in plants. In this study, we identified nine UGlcAE protein-encoding genes in tomato. The nine UGlcAE genes that were distributed on eight chromosomes in tomato, and the corresponding proteins contained one or two trans-membrane domains. The phylogenetic analysis showed that SlUGlcAE genes could be divided into s...

  17. Man o' War Mutation in UDP-α-D-Xylose Synthase Favors the Abortive Catalytic Cycle and Uncovers a Latent Potential for Hexamer Formation

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Jr., Richard M.; Polizzi, Samuel J.; Kadirvelraj, Renuka; Howard, Wesley W.; Wood, Zachary A. [Georgia

    2015-03-17

    The man o’ war (mow) phenotype in zebrafish is characterized by severe craniofacial defects due to a missense mutation in UDP-α-D-xylose synthase (UXS), an essential enzyme in proteoglycan biosynthesis. The mow mutation is located in the UXS dimer interface ~16 Å away from the active site, suggesting an indirect effect on the enzyme mechanism. We have examined the structural and catalytic consequences of the mow mutation (R236H) in the soluble fragment of human UXS (hUXS), which shares 93% sequence identity with the zebrafish enzyme. In solution, hUXS dimers undergo a concentration-dependent association to form a tetramer. Sedimentation velocity studies show that the R236H substitution induces the formation of a new hexameric species. Using two new crystal structures of the hexamer, we show that R236H and R236A substitutions cause a local unfolding of the active site that allows for a rotation of the dimer interface necessary to form the hexamer. The disordered active sites in the R236H and R236A mutant constructs displace Y231, the essential acid/base catalyst in the UXS reaction mechanism. The loss of Y231 favors an abortive catalytic cycle in which the reaction intermediate, UDP-α-D-4-keto-xylose, is not reduced to the final product, UDP-α-D-xylose. Surprisingly, the mow-induced hexamer is almost identical to the hexamers formed by the deeply divergent UXS homologues from Staphylococcus aureus and Helicobacter pylori (21% and 16% sequence identity, respectively). The persistence of a latent hexamer-building interface in the human enzyme suggests that the ancestral UXS may have been a hexamer.

  18. UDP ratios on intake and milk production efficiency in Saanen ewes

    African Journals Online (AJOL)

    Unknown

    Feed intake was significantly influenced by the RDP: UDP ratio and the LD diet achieved a higher feed intake than the MD and HD diets. The HD diet has a better feed conversion efficiency largely due to a better utilisation of body reserves to complement available protein (Change in body Weight, Table 1). The milk ...

  19. Bilirubin UDP-glucuronosyltransferase 1 is the only relevant bilirubin glucuronidating isoform in man

    NARCIS (Netherlands)

    Bosma, P. J.; Seppen, J.; Goldhoorn, B.; Bakker, C.; Oude Elferink, R. P.; Chowdhury, J. R.; Chowdhury, N. R.; Jansen, P. L.

    1994-01-01

    Crigler-Najjar syndrome type I (CN-I) is caused by an inherited absence of UDP-glucuronosyltransferase activity toward bilirubin (B-UGT), resulting in severe non-hemolytic unconjugated hyperbilirubinemia. Based on the expression of cDNAs in COS cells, two UGT isoforms in human liver, B-UGT1 and

  20. Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

    NARCIS (Netherlands)

    Peters, W. H.; Jansen, P. L.

    1986-01-01

    Human liver microsomal bilirubin UDP-glucuronyltransferase catalyzes formation of bilirubin mono- and diglucuronide. KmUDPGA and Vmax of the enzyme are 0.6 mM and 1.69 nmol/mg protein X min. In vitro, bilirubin readily dissolves in the microsomal lipid phase. Taking this into account a Kmbilirubin

  1. Bilirubin glucuronidation by intact Gunn rat fibroblasts expressing bilirubin UDP-glucuronosyltransferase

    NARCIS (Netherlands)

    Seppen, J.; Tada, K.; Hellwig, S.; Bakker, C. T.; Prasad, V. R.; Roy Chowdhury, N.; Roy Chowdhury, J.; Bosma, P. J.; Oude Elferink, R. P.

    1996-01-01

    Crigler-Najjar (CN) disease is an inherited disorder of bilirubin metabolism. The disease is caused by a deficiency of the hepatic enzyme bilirubin UDP-glucuronosyltransferase (B-UGT). Patients with CN disease have high serum levels of the toxic compound, unconjugated bilirubin. The only defect in

  2. Biosynthetic elongation of isolated teichuronic acid polymers via glucosyl- and N-acetylmannosaminuronosyltransferases from solubilized cytoplasmic membrane fragments of Micrococcus luteus.

    Science.gov (United States)

    Hildebrandt, K M; Anderson, J S

    1990-01-01

    Cytoplasmic membrane fragments of Micrococcus luteus catalyze in vitro biosynthesis of teichuronic acid from uridine diphosphate D-glucose (UDP-glucose), uridine diphosphate N-acetyl-D-mannosaminuronic acid (UDP-ManNAcA), and uridine diphosphate N-acetyl-D-glucosamine. Membrane fragments solubilized with Thesit (dodecyl alcohol polyoxyethylene ether) can utilize UDP-glucose and UDP-ManNAcA to effect elongation of teichuronic acid isolated from native cell walls. When UDP-glucose is the only substrate supplied, the detergent-solubilized glucosyltransferase incorporates a single glucosyl residue onto each teichuronic acid acceptor. When both UDP-glucose and UDP-ManNAcA are supplied, the glucosyltransferase and the N-acetylmannosaminuronosyltransferase act cooperatively to elongate the teichuronic acid acceptor by multiple additions of the disaccharide repeat unit. As shown by polyacrylamide gel electrophoresis, low-molecular-weight fractions of teichuronic acid are converted to higher-molecular-weight polymers by the addition of as many as 17 disaccharide repeat units. Images PMID:2118507

  3. Hepatic conversion of bilirubin monoglucuronide to diglucuronide in uridine diphosphate-glucuronyl transferase-deficient man and rat by bilirubin glucuronoside glucuronosyltransferase

    NARCIS (Netherlands)

    Chowdhury, J. R.; Jansen, P. L.; Fischberg, E. B.; Daniller, A.; Arias, I. M.

    1978-01-01

    The microsomal enzyme uridine diphosphate (UDP) glucuronate glucuronyltransferase (E.C. 2.4.1.17) catalyzes formation of bilirubin mono-glucuronide from bilirubin and UDPglucuronic acid. Bilirubin glucuronoside glucuronosyltransferase (E.C. 2.4.1.95), an enzyme concentrated in plasma

  4. A UDP-Glucose:Monoterpenol Glucosyltransferase Adds to the Chemical Diversity of the Grapevine Metabolome1[W

    Science.gov (United States)

    Bönisch, Friedericke; Frotscher, Johanna; Stanitzek, Sarah; Rühl, Ernst; Wüst, Matthias; Bitz, Oliver; Schwab, Wilfried

    2014-01-01

    Terpenoids represent one of the major classes of natural products and serve different biological functions. In grape (Vitis vinifera), a large fraction of these compounds is present as nonvolatile terpene glycosides. We have extracted putative glycosyltransferase (GT) sequences from the grape genome database that show similarity to Arabidopsis (Arabidopsis thaliana) GTs whose encoded proteins glucosylate a diversity of terpenes. Spatial and temporal expression levels of the potential VvGT genes were determined in five different grapevine varieties. Heterologous expression and biochemical assays of candidate genes led to the identification of a UDP-glucose:monoterpenol β-d-glucosyltransferase (VvGT7). The VvGT7 gene was expressed in various tissues in accordance with monoterpenyl glucoside accumulation in grape cultivars. Twelve allelic VvGT7 genes were isolated from five cultivars, and their encoded proteins were biochemically analyzed. They varied in substrate preference and catalytic activity. Three amino acids, which corresponded to none of the determinants previously identified for other plant GTs, were found to be important for enzymatic catalysis. Site-specific mutagenesis along with the analysis of allelic proteins also revealed amino acids that impact catalytic activity and substrate tolerance. These results demonstrate that VvGT7 may contribute to the production of geranyl and neryl glucoside during grape ripening. PMID:24784757

  5. Ultra-deep pyrosequencing (UDPS data treatment to study amplicon HCV minor variants.

    Directory of Open Access Journals (Sweden)

    Josep Gregori

    Full Text Available We have investigated the reliability and reproducibility of HCV viral quasispecies quantification by ultra-deep pyrosequencing (UDPS methods. Our study has been divided in two parts. First of all, by UDPS sequencing of clone mixes samples we have established the global noise level of UDPS and fine tuned a data treatment workflow previously optimized for HBV sequence analysis. Secondly, we have studied the reproducibility of the methodology by comparing 5 amplicons from two patient samples on three massive sequencing platforms (FLX+, FLX and Junior after applying the error filters developed from the clonal/control study. After noise filtering the UDPS results, the three replicates showed the same 12 polymorphic sites above 0.7%, with a mean CV of 4.86%. Two polymorphic sites below 0.6% were identified by two replicates and one replicate respectively. A total of 25, 23 and 26 haplotypes were detected by GS-Junior, GS-FLX and GS-FLX+. The observed CVs for the normalized Shannon entropy (Sn, the mutation frequency (Mf, and the nucleotidic diversity (Pi were 1.46%, 3.96% and 3.78%. The mean absolute difference in the two patients (5 amplicons each, in the GS-FLX and GS-FLX+, were 1.46%, 3.96% and 3.78% for Sn, Mf and Pi. No false polymorphic site was observed above 0.5%. Our results indicate that UDPS is an optimal alternative to molecular cloning for quantitative study of HCV viral quasispecies populations, both in complexity and composition. We propose an UDPS data treatment workflow for amplicons from the RNA viral quasispecies which, at a sequencing depth of at least 10,000 reads per strand, enables to obtain sequences and frequencies of consensus haplotypes above 0.5% abundance with no erroneous mutations, with high confidence, resistant mutants as minor variants at the level of 1%, with high confidence that variants are not missed, and highly confident measures of quasispecies complexity.

  6. A multi-port 10GbE PCIe NIC featuring UDP offload and GPUDirect capabilities

    CERN Document Server

    Ammendola, Roberto; Frezza, Ottorino; Lamanna, Gianluca; Cicero, Francesca Lo; Lonardo, Alessandro; Martinelli, Michele; Paolucci, Pier Stanislao; Pastorelli, Elena; Pontisso, Luca; Rossetti, Davide; Simula, Francesco; Sozzi, Marco; Tosoratto, Laura; Vicini, Piero

    2015-01-01

    NaNet-10 is a four-ports 10GbE PCIe Network Interface Card designed for low-latency real-time operations with GPU systems. To this purpose the design includes an UDP offload module, for fast and clock-cycle deterministic handling of the transport layer protocol, plus a GPUDirect P2P/RDMA engine for low-latency communication with NVIDIA Tesla GPU devices. A dedicated module (Multi-Stream) can optionally process input UDP streams before data is delivered through PCIe DMA to their destination devices, re-organizing data from different streams guaranteeing computational optimization. NaNet-10 is going to be integrated in the NA62 CERN experiment in order to assess the suitability of GPGPU systems as real-time triggers, results and lessons learned while performing this activity will be reported herein.

  7. Characterization of mouse UDP-glucose pyrophosphatase, a Nudix hydrolase encoded by the Nudt14 gene

    Energy Technology Data Exchange (ETDEWEB)

    Heyen, Candy A.; Tagliabracci, Vincent S.; Zhai, Lanmin [Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Roach, Peter J., E-mail: proach@iupui.edu [Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States)

    2009-12-25

    Recombinant mouse UDP-glucose pyrophosphatase (UGPPase), encoded by the Nudt14 gene, was produced in Escherichia coli and purified close to homogeneity. The enzyme catalyzed the conversion of [{beta}-{sup 32}P]UDP-glucose to [{sup 32}P]glucose-1-P and UMP, confirming that it hydrolyzed the pyrophosphate of the nucleoside diphosphate sugar to generate glucose-1-P and UMP. The enzyme was also active toward ADP-ribose. Activity is dependent on the presence of Mg{sup 2+} and was greatest at alkaline pH above 8. Kinetic analysis indicated a K{sub m} of {approx}4 mM for UDP-glucose and {approx}0.3 mM for ADP-ribose. Based on V{sub max}/K{sub m} values, the enzyme was {approx}20-fold more active toward ADP-ribose. UGPPase behaves as a dimer in solution and can be cross-linked to generate a species of M{sub r} 54,000 from a monomer of 30,000 as judged by SDS-PAGE. The dimerization was not affected by the presence of glucose-1-P or UDP-glucose. Using antibodies raised against the recombinant protein, Western analysis indicated that UGPPase was widely expressed in mouse tissues, including skeletal muscle, liver, kidney, heart, lung, fat, heart and pancreas with a lower level in brain. It was generally present as a doublet when analyzed by SDS-PAGE, suggesting the occurrence of some form of post-translational modification. Efforts to interconvert the species by adding or inhibiting phosphatase activity were unsuccessful, leaving the nature of the modification unknown. Sequence alignments and database searches revealed related proteins in species as distant as Drosophila melanogaster and Caenorhabditis elegans.

  8. Phylogenomic analysis of UDP glycosyltransferase 1 multigene family in Linum usitatissimum identified genes with varied expression patterns

    Science.gov (United States)

    2012-01-01

    Background The glycosylation process, catalyzed by ubiquitous glycosyltransferase (GT) family enzymes, is a prevalent modification of plant secondary metabolites that regulates various functions such as hormone homeostasis, detoxification of xenobiotics and biosynthesis and storage of secondary metabolites. Flax (Linum usitatissimum L.) is a commercially grown oilseed crop, important because of its essential fatty acids and health promoting lignans. Identification and characterization of UDP glycosyltransferase (UGT) genes from flax could provide valuable basic information about this important gene family and help to explain the seed specific glycosylated metabolite accumulation and other processes in plants. Plant genome sequencing projects are useful to discover complexity within this gene family and also pave way for the development of functional genomics approaches. Results Taking advantage of the newly assembled draft genome sequence of flax, we identified 137 UDP glycosyltransferase (UGT) genes from flax using a conserved signature motif. Phylogenetic analysis of these protein sequences clustered them into 14 major groups (A-N). Expression patterns of these genes were investigated using publicly available expressed sequence tag (EST), microarray data and reverse transcription quantitative real time PCR (RT-qPCR). Seventy-three per cent of these genes (100 out of 137) showed expression evidence in 15 tissues examined and indicated varied expression profiles. The RT-qPCR results of 10 selected genes were also coherent with the digital expression analysis. Interestingly, five duplicated UGT genes were identified, which showed differential expression in various tissues. Of the seven intron loss/gain positions detected, two intron positions were conserved among most of the UGTs, although a clear relationship about the evolution of these genes could not be established. Comparison of the flax UGTs with orthologs from four other sequenced dicot genomes indicated that

  9. Phylogenomic analysis of UDP glycosyltransferase 1 multigene family in Linum usitatissimum identified genes with varied expression patterns

    Directory of Open Access Journals (Sweden)

    Barvkar Vitthal T

    2012-05-01

    Full Text Available Abstract Background The glycosylation process, catalyzed by ubiquitous glycosyltransferase (GT family enzymes, is a prevalent modification of plant secondary metabolites that regulates various functions such as hormone homeostasis, detoxification of xenobiotics and biosynthesis and storage of secondary metabolites. Flax (Linum usitatissimum L. is a commercially grown oilseed crop, important because of its essential fatty acids and health promoting lignans. Identification and characterization of UDP glycosyltransferase (UGT genes from flax could provide valuable basic information about this important gene family and help to explain the seed specific glycosylated metabolite accumulation and other processes in plants. Plant genome sequencing projects are useful to discover complexity within this gene family and also pave way for the development of functional genomics approaches. Results Taking advantage of the newly assembled draft genome sequence of flax, we identified 137 UDP glycosyltransferase (UGT genes from flax using a conserved signature motif. Phylogenetic analysis of these protein sequences clustered them into 14 major groups (A-N. Expression patterns of these genes were investigated using publicly available expressed sequence tag (EST, microarray data and reverse transcription quantitative real time PCR (RT-qPCR. Seventy-three per cent of these genes (100 out of 137 showed expression evidence in 15 tissues examined and indicated varied expression profiles. The RT-qPCR results of 10 selected genes were also coherent with the digital expression analysis. Interestingly, five duplicated UGT genes were identified, which showed differential expression in various tissues. Of the seven intron loss/gain positions detected, two intron positions were conserved among most of the UGTs, although a clear relationship about the evolution of these genes could not be established. Comparison of the flax UGTs with orthologs from four other sequenced dicot

  10. Elucidation of substrate specificity in Aspergillus nidulans UDP-galactose-4-epimerase.

    Directory of Open Access Journals (Sweden)

    Sean A Dalrymple

    Full Text Available The frequency of invasive fungal infections has rapidly increased in recent years. Current clinical treatments are experiencing decreased potency due to severe host toxicity and the emergence of fungal drug resistance. As such, new targets and their corresponding synthetic pathways need to be explored for drug development purposes. In this context, galactofuranose residues, which are employed in fungal cell wall construction, but are notably absent in animals, represent an appealing target. Herein we present the structural and biochemical characterization of UDP-galactose-4-epimerase from Aspergillus nidulans which produces the precursor UDP-galactopyranose required for galactofuranose synthesis. Examination of the structural model revealed both NAD(+ and UDP-glucopyranose were bound within the active site cleft in a near identical fashion to that found in the Human epimerase. Mutational studies on the conserved catalytic motif support a similar mechanism to that established for the Human counterpart is likely operational within the A. nidulans epimerase. While the K m and k cat for the enzyme were determined to be 0.11 mM and 12.8 s(-1, respectively, a single point mutation, namely L320C, activated the enzyme towards larger N-acetylated substrates. Docking studies designed to probe active site affinity corroborate the experimentally determined activity profiles and support the kinetic inhibition results.

  11. Determination of the energetics of the UDP-glucose pyrophosphorylase reaction by positional isotope exchange inhibition

    International Nuclear Information System (INIS)

    Hester, L.S.; Raushel, F.M.

    1987-01-01

    A method has been developed for obtaining qualitative information about enzyme-catalyzed reactions by measuring the inhibitory effects of added substrates on positional isotope exchange rates. It has been demonstrated for ordered kinetic mechanisms that an increase in the concentration of the second substrate to add to the enzyme will result in a linear increase in the ratio of the chemical and positional isotope exchange rates. The slopes and intercepts from these plots can be used to determine the partitioning ratios of binary and ternary enzyme complexes. The method has been applied to the reaction catalyzed by UDP-glucose pyrophosphorylase. A positional isotope exchange reaction was measured within oxygen-18-labeled UTP as a function of variable glucose 1-phosphate concentration in the forward reaction. In the reverse reaction, a positional isotope exchange reaction was measured within oxygen-18-labeled UDP-glucose as a function of increasing pyrophosphate concentration. The results have been interpreted to indicate that the interconversion of the ternary central complexes is fast relative to product dissociation in either direction. In the forward direction, the release of UDP-glucose is slower than the release of pyrophosphate. The release of glucose 1-phosphate is slower than the release of UTP in the reverse reaction

  12. Identification and functional analysis of two Golgi-localized UDP-galactofuranose transporters with overlapping functions in Aspergillus niger.

    Science.gov (United States)

    Park, Joohae; Tefsen, Boris; Heemskerk, Marc J; Lagendijk, Ellen L; van den Hondel, Cees A M J J; van Die, Irma; Ram, Arthur F J

    2015-11-02

    Galactofuranose (Galf)-containing glycoconjugates are present in numerous microbes, including filamentous fungi where they are important for morphology, virulence and maintaining cell wall integrity. The incorporation of Galf-residues into galactomannan, galactomannoproteins and glycolipids is carried out by Golgi-localized Galf transferases. The nucleotide sugar donor used by these transferases (UDP-Galf) is produced in the cytoplasm and has to be transported to the lumen of the Golgi by a dedicated nucleotide sugar transporter. Based on homology with recently identified UDP-Galf-transporters in A. fumigatus and A. nidulans, two putative UDP-Galf-transporters in A. niger were found. Their function and localization was determined by gene deletions and GFP-tagging studies, respectively. The two putative UDP-Galf-transporters in A. niger are homologous to each other and are predicted to contain eleven transmembrane domains (UgtA) or ten transmembrane domains (UgtB) due to a reduced length of the C-terminal part of the UgtB protein. The presence of two putative UDP-Galf-transporters in the genome was not unique for A. niger. From the twenty Aspergillus species analysed, nine species contained two additional putative UDP-Galf-transporters. Three of the nine species were outside the Aspergillus section nigri, indication an early duplication of UDP-Galf-transporters and subsequent loss of the UgtB copy in several aspergilli. Deletion analysis of the single and double mutants in A. niger indicated that the two putative UDP-Galf-transporters (named UgtA and UgtB) have a redundant function in UDP-Galf-transport as only the double mutant displayed a Galf-negative phenotype. The Galf-negative phenotype of the double mutant could be complemented by expressing either CFP-UgtA or CFP-UgtB fusion proteins from their endogenous promoters, indicating that both CFP-tagged proteins are functional. Both Ugt proteins co-localize with each other as well as with the GDP

  13. Different temperatures select distinctive acetic acid bacteria species and promotes organic acids production during Kombucha tea fermentation.

    Science.gov (United States)

    De Filippis, Francesca; Troise, Antonio Dario; Vitaglione, Paola; Ercolini, Danilo

    2018-08-01

    Kombucha is a traditional beverage produced by tea fermentation, carried out by a symbiotic consortium of bacteria and yeasts. Acetic Acid Bacteria (AAB) usually dominate the bacterial community of Kombucha, driving the fermentative process. The consumption of this beverage was often associated to beneficial effects for the health, due to its antioxidant and detoxifying properties. We characterized bacterial populations of Kombucha tea fermented at 20 or 30 °C by using culture-dependent and -independent methods and monitored the concentration of gluconic and glucuronic acids, as well as of total polyphenols. We found significant differences in the microbiota at the two temperatures. Moreover, different species of Gluconacetobacter were selected, leading to a differential abundance of gluconic and glucuronic acids. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Cell wall composition and digestibility alterations in Brachypodium distachyon achieved through reduced expression of the UDP-arabinopyranose mutase

    Science.gov (United States)

    Rancour, David M.; Hatfield, Ronald D.; Marita, Jane M.; Rohr, Nicholas A.; Schmitz, Robert J.

    2015-01-01

    Nucleotide-activated sugars are essential substrates for plant cell-wall carbohydrate-polymer biosynthesis. The most prevalent grass cell wall (CW) sugars are glucose (Glc), xylose (Xyl), and arabinose (Ara). These sugars are biosynthetically related via the UDP–sugar interconversion pathway. We sought to target and generate UDP–sugar interconversion pathway transgenic Brachypodium distachyon lines resulting in CW carbohydrate composition changes with improved digestibility and normal plant stature. Both RNAi-mediated gene-suppression and constitutive gene-expression approaches were performed. CWs from 336 T0 transgenic plants with normal appearance were screened for complete carbohydrate composition. RNAi mutants of BdRGP1, a UDP-arabinopyranose mutase, resulted in large alterations in CW carbohydrate composition with significant decreases in CW Ara content but with minimal change in plant stature. Five independent RNAi-RGP1 T1 plant lines were used for in-depth analysis of plant CWs. Real-time PCR analysis indicated that gene expression levels for BdRGP1, BdRGP2, and BdRGP3 were reduced in RNAi-RGP1 plants to 15–20% of controls. CW Ara content was reduced by 23–51% of control levels. No alterations in CW Xyl and Glc content were observed. Corresponding decreases in CW ferulic acid (FA) and ferulic acid-dimers (FA-dimers) were observed. Additionally, CW p-coumarates (pCA) were decreased. We demonstrate the CW pCA decrease corresponds to Ara-coupled pCA. Xylanase-mediated digestibility of RNAi-RGP1 Brachypodium CWs resulted in a near twofold increase of released total carbohydrate. However, cellulolytic hydrolysis of CW material was inhibited in leaves of RNAi-RGP1 mutants. Our results indicate that targeted manipulation of UDP–sugar biosynthesis can result in biomass with substantially altered compositions and highlights the complex effect CW composition has on digestibility. PMID:26136761

  15. Lactic acid bacteria: promising supplements for enhancing the biological activities of kombucha.

    Science.gov (United States)

    Nguyen, Nguyen Khoi; Dong, Ngan Thi Ngoc; Nguyen, Huong Thuy; Le, Phu Hong

    2015-01-01

    Kombucha is sweetened black tea that is fermented by a symbiosis of bacteria and yeast embedded within a cellulose membrane. It is considered a health drink in many countries because it is a rich source of vitamins and may have other health benefits. It has previously been reported that adding lactic acid bacteria (Lactobacillus) strains to kombucha can enhance its biological functions, but in that study only lactic acid bacteria isolated from kefir grains were tested. There are many other natural sources of lactic acid bacteria. In this study, we examined the effects of lactic acid bacteria from various fermented Vietnamese food sources (pickled cabbage, kefir and kombucha) on kombucha's three main biological functions: glucuronic acid production, antibacterial activity and antioxidant ability. Glucuronic acid production was determined by high-performance liquid chromatography-mass spectrometry, antibacterial activity was assessed by the agar-well diffusion method and antioxidant ability was evaluated by determining the 2,2-diphenyl-1-picrylhydrazyl radical scavenging capacity. Four strains of food-borne pathogenic bacteria were used in our antibacterial experiments: Listeria monocytogenes ATCC 19111, Escherichia coli ATCC 8739, Salmonella typhimurium ATCC 14028 and Bacillus cereus ATCC 11778. Our findings showed that lactic acid bacteria strains isolated from kefir are superior to those from other sources for improving glucuronic acid production and enhancing the antibacterial and antioxidant activities of kombucha. This study illustrates the potential of Lactobacillus casei and Lactobacillus plantarum isolated from kefir as biosupplements for enhancing the bioactivities of kombucha.

  16. Biochemical characterization of UDP-N-acetylmuramoyl-L-alanyl-D-glutamate: meso-2,6-diaminopimelate ligase (MurE from Verrucomicrobium spinosum DSM 4136(T..

    Directory of Open Access Journals (Sweden)

    Sean E McGroty

    Full Text Available Verrucomicrobium spinosum is a Gram-negative bacterium that is related to bacteria from the genus Chlamydia. The bacterium is pathogenic towards Drosophila melanogaster and Caenorhabditis elegans, using a type III secretion system to facilitate pathogenicity. V. spinosum employs the recently discovered l,l-diaminopimelate aminotransferase biosynthetic pathway to generate the bacterial cell wall and protein precursors diaminopimelate and lysine. A survey of the V. spinosum genome provides evidence that the bacterium should be able to synthesize peptidoglycan de novo, since all of the necessary genes are present. The enzyme UDP-N-acetylmuramoyl-l-alanyl-d-glutamate: meso-2,6-diaminopimelate ligase (MurE (E.C. 6.3.2.15 catalyzes a reaction in the cytoplasmic step of peptidoglycan biosynthesis by adding the third amino acid residue to the peptide stem. The murE ortholog from V. spinosum (murE Vs was cloned and was shown to possess UDP-MurNAc-l-Ala-d-Glu:meso-2,6-diaminopimelate ligase activity in vivo using functional complementation. In vitro analysis using the purified recombinant enzyme demonstrated that MurEVs has a pH optimum of 9.6 and a magnesium optimum of 30 mM. meso-Diaminopimelate was the preferred substrate with a K m of 17 µM, when compared to other substrates that are structurally related. Sequence alignment and structural analysis using homology modeling suggest that key residues that make up the active site of the enzyme are conserved in MurEVs. Our kinetic analysis and structural model of MurEVs is consistent with other MurE enzymes from Gram-negative bacteria that have been characterized. To verify that V. spinosum incorporates diaminopimelate into its cell wall, we purified peptidoglycan from a V. spinosum culture; analysis revealed the presence of diaminopimelate, consistent with that of a bona fide peptidoglycan from Gram-negative bacteria.

  17. Analysis of the polymerization initiation and activity of Pasteurella multocida heparosan synthase PmHS2, an enzyme with glycosyltransferase and UDP-sugar hydrolase activity

    NARCIS (Netherlands)

    Chavaroche, A.A.E.; Broek, van den L.A.M.; Springer, J.; Boeriu, C.; Eggink, G.

    2011-01-01

    Heparosan synthase catalyzes the polymerization of heparosan [-4GlcUAß1-4GlcNAca1-]n by transferring alternatively the monosaccharide units from UDP-GlcUA and UDP-GlcNAc to an acceptor molecule. Details on the heparosan chain initiation by Pasteurella multocida heparosan synthase PmHS2 and its

  18. Substituent-specific antibody against glucuronoxylan reveals close association of glucuronic acid and acetyl substituents and distinct labeling patterns in tree species

    DEFF Research Database (Denmark)

    Koutaniemi, Sanna; Guillon, Fabienne; Tranquet, Olivier

    2012-01-01

    Immunolabeling can be used to locate plant cell wall carbohydrates or other components to specific cell types or to specific regions of the wall. Some antibodies against xylans exist; however, many partly react with the xylan backbone and thus provide limited information on the type of substituen...

  19. Tilia tomentosa pectins exhibit dual mode of action on phagocytes as beta-glucuronic acid monomers are abundant in their rhamnogalacturonans I

    Czech Academy of Sciences Publication Activity Database

    Georgiev, Y.N.; Paulsen, B.S.; Kiyohara, H.; Číž, Milan; Ognyanov, M.H.; Vašíček, Ondřej; Rise, F.; Denev, P.; Lojek, Antonín; Batsalova, T.G.; Dzhambazov, B.M.; Yamada, H.; Lund, R.; Barsett, H.; Krastanov, A.I.; Yanakieva, I.Z.; Kratchanova, M.

    2017-01-01

    Roč. 175, NOV2017 (2017), s. 178-191 ISSN 0144-8617 Grant - others:GA MŠk(CZ) LQ1605 Institutional support: RVO:68081707 Keywords : biophytum-petersianum klotzsch * nitric-oxide production Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.811, year: 2016

  20. Synthesis of α- and β-D-glucopyranuronate 1-phosphate and α-D-glucopyranuronate 1-fluoride: intermediates in the synthesis of D-glucuronic acid from starch

    NARCIS (Netherlands)

    Heeres, André; Van Doren, Henk A.; Gotlieb, Kees F.; Bleeker, Ido P.

    1997-01-01

    The title uronates were prepared by 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) catalysed sodium hypochlorite oxidation of α- and β-D-glucopyranosylphosphate (α-/β-Glc-1-P) and α-D-glucopyranosyl fluoride (α-Glc-1-F). Quantitative recovery of the TEMPO catalyst was achieved by azeotropic

  1. Effects of model traumatic injury on hepatic drug metabolism in the rat. IV. Glucuronidation.

    Science.gov (United States)

    Griffeth, L K; Rosen, G M; Rauckman, E J

    1985-01-01

    A previously validated small mammal trauma model, hind-limb ischemia secondary to infrarenal aortic ligation in the rat, was utilized to investigate the effects of traumatic injury on hepatic glucuronidation activity. As was previously observed with hepatic oxidative drug metabolism, model trauma resulted in a significant decrease in the in vivo glucuronidation of chloramphenicol, with a 23% drop in clearance of this drug. The effect on in vivo pharmacokinetics appeared to result from a complex interaction between trauma's differential influences on conjugating enzyme(s), deconjugating enzyme(s), and hepatic UDP-glucuronic acid levels, as well as the relative physiological importance of these variables. Hepatic UDP-glucuronyltransferase activities towards both p-nitrophenol and chloramphenicol were elevated (44-54%) after model injury when measured in native hepatic microsomes. However, microsomes which had been "activated" by treatment with Triton X-100 showed no significant difference between control and traumatized animals. Serum beta-glucuronidase activities were elevated by 58%, while hepatic beta-glucuronidase rose by about 16%. Nevertheless, in vivo deconjugation showed no significant change. Model trauma also resulted in a 46% decrease in hepatic UDP-glucuronic acid content. Thus, the observed post-traumatic depression of in vivo chloramphenicol glucuronidation could be due either to a diminished availability of a necessary cofactor (UDP-glucuronic acid) or to an alteration in enzyme kinetics or function in vivo.

  2. Dermatan Sulfate Epimerase 1-Deficient Mice Have Reduced Content and Changed Distribution of Iduronic Acids in Dermatan Sulfate and an Altered Collagen Structure in Skin

    DEFF Research Database (Denmark)

    Maccarana, M.; Kalamajski, S.; Kongsgaard, M.

    2009-01-01

    Dermatan sulfate epimerase 1 (DS-epi1) and DS-epi2 convert glucuronic acid to iduronic acid in chondroitin/dermatan sulfate biosynthesis. Here we report on the generation of DS-epi1-null mice and the resulting alterations in the chondroitin/dermatan polysaccharide chains. The numbers of long blocks...... of adjacent iduronic acids are greatly decreased in skin decorin and biglycan chondroitin/dermatan sulfate, along with a parallel decrease in iduronic-2-O-sulfated-galactosamine-4-O-sulfated structures. Both iduronic acid blocks and iduronic acids surrounded by glucuronic acids are also decreased in versican......-derived chains. DS-epi1-deficient mice are smaller than their wild-type littermates but otherwise have no gross macroscopic alterations. The lack of DS-epi1 affects the chondroitin/dermatan sulfate in many proteoglycans, and the consequences for skin collagen structure were initially analyzed. We found...

  3. Deficient UDP-glucuronosyltransferase detoxification enzyme activity in the small intestinal mucosa of patients with coeliac disease.

    NARCIS (Netherlands)

    Goerres, M.S.; Roelofs, H.M.J.; Jansen, J.B.M.J.; Peters, W.H.M.

    2006-01-01

    BACKGROUND: Small intestinal malignancies in humans are rare; however, patients with coeliac disease have a relatively high risk for such tumours. Intestinal UDP-glucuronosyltransferases are phase II drug metabolism enzymes also involved in the detoxification of ingested toxins and carcinogens. As

  4. Genetic polymorphisms in UDP-glucuronosyltransferase 1A6 are not associated with NSAIDs-related peptic ulcer haemorrhage

    NARCIS (Netherlands)

    van Oijen, Martijn G. H.; Koetsier, Marjolein I. A.; Laheij, Robert J. F.; Roelofs, Hennie M. J.; te Morsche, René H. M.; Peters, Wilbert H. M.; Verheugt, Freek W. A.; Jansen, Jan B. M. J.; Drenth, Joost P. H.

    2009-01-01

    UDP-glucuronosyltransferase 1A6 (UGT1A6) is involved in metabolizing non-steroidal anti-inflammatory drugs (NSAIDs). Genotype variation in UGT1A6 may influence the metabolism of NSAIDs and we studied whether this might modulate the gastrointestinal toxicity of NSAIDs. UGT1A6 genotypes of 114

  5. The lectin domain of UDP-N-acetyl-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase-T4 directs its glycopeptide specificities

    DEFF Research Database (Denmark)

    Hassan, H; Reis, C A; Bennett, E P

    2000-01-01

    The initiation step of mucin-type O-glycosylation is controlled by a large family of homologous UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases). Differences in kinetic properties, substrate specificities, and expression patterns of these isoenzymes provide for diff...

  6. UDP/P2Y6 receptor signaling regulates IgE-dependent degranulation in human basophils

    Directory of Open Access Journals (Sweden)

    Manabu Nakano

    2017-10-01

    Conclusions: This study showed that UDP/P2Y6 receptor signaling is involved in the regulation of IgE-dependent degranulation in basophils, which might stimulate the P2Y6 receptor via the autocrine secretion of UTP. Thus, this receptor represents a potential target to regulate IgE-dependent degranulation in basophils during allergic diseases.

  7. Activities of UDP-glucuronyltransferase, beta-glucuronidase and deiodinase types I and II in hyper- and hypothyroid rats

    NARCIS (Netherlands)

    Heide, S.M. van der; Joosten, B.H.G.M.; Everts, M.E.; Klaren, P.H.M.

    2004-01-01

    We have investigated the hypothesis that uridine 5'-diphosphate (UDP)-glucuronyltransferases (UGTs) and beta-glucuronidase are jointly involved in a mechanism for the storage and mobilization of iodothyronine metabolites in liver, kidney, heart and brain. Specifically, we predicted UGT activities to

  8. Integrated process design for biocatalytic synthesis by a Leloir Glycosyltransferase: UDP-glucose production with sucrose synthase.

    Science.gov (United States)

    Schmölzer, Katharina; Lemmerer, Martin; Gutmann, Alexander; Nidetzky, Bernd

    2017-04-01

    Nucleotide sugar-dependent ("Leloir") glycosyltransferases (GTs), represent a new paradigm for the application of biocatalytic glycosylations to the production of fine chemicals. However, it remains to be shown that GT processes meet the high efficiency targets of industrial biotransformations. We demonstrate in this study of uridine-5'-diphosphate glucose (UDP-glc) production by sucrose synthase (from Acidithiobacillus caldus) that a holistic process design, involving coordinated development of biocatalyst production, biotransformation, and downstream processing (DSP) was vital for target achievement at ∼100 g scale synthesis. Constitutive expression in Escherichia coli shifted the recombinant protein production mainly to the stationary phase and enhanced the specific enzyme activity to a level (∼480 U/g cell dry weight ) suitable for whole-cell biotransformation. The UDP-glc production had excellent performance metrics of ∼100 g product /L, 86% yield (based on UDP), and a total turnover number of 103 g UDP-glc /g cell dry weight at a space-time yield of 10 g/L/h. Using efficient chromatography-free DSP, the UDP-glc was isolated in a single batch with ≥90% purity and in 73% isolated yield. Overall, the process would allow production of ∼0.7 kg of isolated product/L E. coli bioreactor culture, thus demonstrating how integrated process design promotes the practical use of a GT conversion. Biotechnol. Bioeng. 2017;114: 924-928. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Acid dissociation constants of uridine-5 Prime -diphosphate compounds determined by {sup 31}phosphorus nuclear magnetic resonance spectroscopy and internal pH referencing

    Energy Technology Data Exchange (ETDEWEB)

    Jancan, Igor [Louisiana State University, Department of Chemistry, Baton Rouge, LA 70803 (United States); Macnaughtan, Megan A., E-mail: macnau@lsu.edu [Louisiana State University, Department of Chemistry, Baton Rouge, LA 70803 (United States)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The first reported phosphate and imide pK{sub a} values of UDP-GlcNAc and UDP-S-GlcNAc. Black-Right-Pointing-Pointer New role for the monosaccharide in the imide pK{sub a} of uridine-5 Prime -phosphate compounds. Black-Right-Pointing-Pointer UDP-S-GlcNAc and UDP-GlcNAc have the same phosphate pK{sub a}, unlike thioyl analogs. Black-Right-Pointing-Pointer The {sup 31}P chemical shift of inorganic phosphate is a viable internal pH reference. Black-Right-Pointing-Pointer Stability of the external {sup 31}P chemical shift reference is essential. - Abstract: The acid dissociation constant (pK{sub a}) of small, biological molecules is an important physical property used for investigating enzyme mechanisms and inhibitor design. For phosphorus-containing molecules, the {sup 31}P nuclear magnetic resonance (NMR) chemical shift is sensitive to the local chemical environment, particularly to changes in the electronic state of the molecule. Taking advantage of this property, we present a {sup 31}P NMR approach that uses inorganic phosphate buffer as an internal pH reference to determine the pK{sub a} values of the imide and second diphosphate of uridine-5 Prime -diphosphate compounds, including the first reported values for UDP-GlcNAc and UDP-S-GlcNAc. New methods for using inorganic phosphate buffer as an internal pH reference, involving mathematical correction factors and careful control of the chemical shift reference sample, are illustrated. A comparison of the newly determined imide and diphosphate pK{sub a} values of UDP, UDP-GlcNAc, and UDP-S-GlcNAc with other nucleotide phosphate and thio-analogs reveals the significance of the monosaccharide and sulfur position on the pK{sub a} values.

  10. Synthesis and Evaluation of Bicyclo[3.1.0]hexane-Based UDP-Galf Analogues as Inhibitors of the Mycobacterial Galactofuranosyltransferase GlfT2

    Directory of Open Access Journals (Sweden)

    Todd L. Lowary

    2016-08-01

    Full Text Available UDP-galactofuranose (UDP-Galf is the donor substrate for both bifunctional galactofuranosyltransferases, GlfT1 and GlfT2, which are involved in the biosynthesis of mycobacterial galactan. In this paper, a group of UDP-Galf mimics were synthesized via reductive amination of a bicyclo[3.1.0]hexane-based amine by reacting with aromatic, linear, or uridine-containing aldehydes. These compounds were evaluated against GlfT2 using a coupled spectrophotometric assay, and were shown to be weak inhibitors of the enzyme.

  11. Enantioselective inhibition of carprofen towards UDP-glucuronosyltransferase (UGT) 2B7.

    Science.gov (United States)

    Fang, Zhong-Ze; Wang, Haina; Cao, Yun-Feng; Sun, Dong-Xue; Wang, Li-Xuan; Hong, Mo; Huang, Ting; Chen, Jian-Xing; Zeng, Jia

    2015-03-01

    UDP-glucuronosyltransferases (UGTs)-catalyzed glucuronidation conjugation reaction plays an important role in the elimination of many important clinical drugs and endogenous substances. The present study aims to investigate the enantioselective inhibition of carprofen towards UGT isoforms. In vitro a recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU) glucuronidation incubation mixture was used to screen the inhibition potential of (R)-carprofen and (S)-carprofen towards multiple UGT isoforms. The results showed that (S)-carprofen exhibited stronger inhibition potential than (R)-carprofen towards UGT2B7. However, no significant difference was observed for the inhibition of (R)-carprofen and (S)-carprofen towards other UGT isoforms. Furthermore, the inhibition kinetic behavior was compared for the inhibition of (S)-carprofen and (R)-carprofen towards UGT2B7. A Lineweaver-Burk plot showed that both (S)-carprofen and (R)-carprofen exhibited competitive inhibition towards UGT2B7-catalyzed 4-MU glucuronidation. The inhibition kinetic parameter (Ki ) was calculated to be 7.0 μM and 31.1 μM for (S)-carprofen and (R)-carprofen, respectively. Based on the standard for drug-drug interaction, the threshold for (S)-carprofen and (R)-carprofen to induce a drug-drug interaction is 0.7 μM and 3.1 μM, respectively. In conclusion, enantioselective inhibition of carprofen towards UDP-glucuronosyltransferase (UGT) 2B7 was demonstrated in the present study. Using the in vitro inhibition kinetic parameter, the concentration threshold of (S)-carprofen and (R)-carprofen to possibly induce the drug-drug interaction was obtained. Therefore, clinical monitoring of the plasma concentration of (S)-carprofen is more important than (R)-carprofen to avoid a possible drug-drug interaction between carprofen and the drugs mainly undergoing UGT2B7-catalyzed metabolism. © 2014 Wiley Periodicals, Inc.

  12. Determinants and Expansion of Specificity in a Trichothecene UDP-Glucosyltransferase from Oryza sativa.

    Science.gov (United States)

    Wetterhorn, Karl M; Gabardi, Kaitlyn; Michlmayr, Herbert; Malachova, Alexandra; Busman, Mark; McCormick, Susan P; Berthiller, Franz; Adam, Gerhard; Rayment, Ivan

    2017-12-19

    Family 1 UDP-glycosyltransferases (UGTs) in plants primarily form glucose conjugates of small molecules and, besides other functions, play a role in detoxification of xenobiotics. Indeed, overexpression of a barley UGT in wheat has been shown to control Fusarium head blight, which is a plant disease of global significance that leads to reduced crop yields and contamination with trichothecene mycotoxins such as deoxynivalenol (DON), T-2 toxin, and many other structural variants. The UGT Os79 from rice has emerged as a promising candidate for inactivation of mycotoxins because of its ability to glycosylate DON, nivalenol, and hydrolyzed T-2 toxin (HT-2). However, Os79 is unable to modify T-2 toxin (T-2), produced by pathogens such as Fusarium sporotrichioides and Fusarium langsethii. Activity toward T-2 is desirable because it would allow a single UGT to inactivate co-occurring mycotoxins. Here, the structure of Os79 in complex with the products UDP and deoxynivalenol 3-O-glucoside is reported together with a kinetic analysis of a broad range of trichothecene mycotoxins. Residues associated with the trichothecene binding pocket were examined by site-directed mutagenesis that revealed that trichothecenes substituted at the C4 position, which are not glycosylated by wild-type Os79, can be accommodated in the binding pocket by increasing its volume. The H122A/L123A/Q202L triple mutation, which increases the volume of the active site and attenuates polar contacts, led to strong and equivalent activity toward trichothecenes with C4 acetyl groups. This mutant enzyme provides the broad specificity required to control multiple toxins produced by different Fusarium species and chemotypes.

  13. Comparison of the inhibition capability of oleanolic acid and ...

    African Journals Online (AJOL)

    Background: Human UDP-glucuronosyltransferases (UGTs) are important membrane proteins located in endoplasmic reticulum, and play important roles in metabolism of a variety of endogenous and exogenous compounds. Aims: To determine the influence of subtle difference in the structure of oleanolic acid and betulinic ...

  14. Functional polymorphisms of UDP-glucuronosyltransferases 1A1, 1A6 and 1A8 are not involved in chronic pancreatitis.

    NARCIS (Netherlands)

    Verlaan, M.; Morsche, R.H.M. te; Pap, A.; Laheij, R.J.F.; Jansen, J.B.M.J.; Peters, W.H.M.; Drenth, J.P.H.

    2004-01-01

    OBJECTIVES: Chronic pancreatitis (CP) is associated with alcohol abuse, smoking and other dietary or environmental factors. UDP-glucuronosyltransferases (UGTs) are phase II detoxifying enzymes responsible for glucuronidation of various exogenous and endogenous compounds. Genetic variations,

  15. A tandem array of UDP-glycosyltransferases from the UGT73C subfamily glycosylate sapogenins, forming a spectrum of mono- and bisdesmosidic saponins.

    Science.gov (United States)

    Erthmann, Pernille Østerbye; Agerbirk, Niels; Bak, Søren

    2018-05-01

    This study identifies six UGT73Cs all able to glucosylate sapogenins at positions 3 and/or 28 which demonstrates that B. vulgaris has a much richer arsenal of UGTs involved in saponin biosynthesis than initially anticipated. The wild cruciferous plant Barbarea vulgaris is resistant to some insects due to accumulation of two monodesmosidic triterpenoid saponins, oleanolic acid 3-O-β-cellobioside and hederagenin 3-O-β-cellobioside. Insect resistance depends on the structure of the sapogenin aglycone and the glycosylation pattern. The B. vulgaris saponin profile is complex with at least 49 saponin-like metabolites, derived from eight sapogenins and including up to five monosaccharide units. Two B. vulgaris UDP-glycosyltransferases, UGT73C11 and UGT73C13, O-glucosylate sapogenins at positions 3 and 28, forming mainly 3-O-β-D-glucosides. The aim of this study was to identify UGTs responsible for the diverse saponin oligoglycoside moieties observed in B. vulgaris. Twenty UGT genes from the insect resistant genotype were selected and heterologously expressed in Nicotiana benthamiana and/or Escherichia coli. The extracts were screened for their ability to glycosylate sapogenins (oleanolic acid, hederagenin), the hormone 24-epibrassinolide and sapogenin monoglucosides (hederagenin and oleanolic acid 3-O-β-D-glucosides). Six UGTs from the UGT73C subfamily were able to glucosylate both sapogenins and both monoglucosides at positions 3 and/or 28. Some UGTs formed bisdesmosidic saponins efficiently. At least four UGT73C genes were localized in a tandem array with UGT73C11 and possibly UGT73C13. This organization most likely reflects duplication events followed by sub- and neofunctionalization. Indeed, signs of positive selection on several amino acid sites were identified and modelled to be localized on the UGT protein surface. This tandem array is proposed to initiate higher order bisdesmosidic glycosylation of B. vulgaris saponins, leading to the recently discovered

  16. Role of extrahepatic UDP-glucuronosyltransferase 1A1: advances in understanding breast milk-induced neonatal hyperbilirubinemia

    OpenAIRE

    Fujiwara, Ryoichi; Maruo, Yoshihiro; Chen, Shujuan; Tukey, Robert H.

    2015-01-01

    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic ...

  17. Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene

    OpenAIRE

    Franken, S; Wittke, D; Mansson, JE; D'Hooge, R; De Deyn, PP; Lüllmann-Rauch, R; Matzner, U; Gieselmann, V

    2006-01-01

    Summary Background Arylsulfatase A (ASA)-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT). This deficiency is known to lead to a decreased synthesis of gal...

  18. Comparison of the UDP-N-Acetylmuramate:l-Alanine Ligase Enzymes from Mycobacterium tuberculosis and Mycobacterium leprae

    Science.gov (United States)

    Mahapatra, Sebabrata; Crick, Dean C.; Brennan, Patrick J.

    2000-01-01

    In the peptidoglycan of Mycobacterium leprae, l-alanine of the side chain is replaced by glycine. When expressed in Escherichia coli, MurC (UDP-N-acetyl-muramate:l-alanine ligase) of M. leprae showed Km and Vmax for l-alanine and glycine similar to those of Mycobacterium tuberculosis MurC, suggesting that another explanation should be sought for the presence of glycine. PMID:11073931

  19. Comparison of the UDP-N-Acetylmuramate:l-Alanine Ligase Enzymes from Mycobacterium tuberculosis and Mycobacterium leprae

    OpenAIRE

    Mahapatra, Sebabrata; Crick, Dean C.; Brennan, Patrick J.

    2000-01-01

    In the peptidoglycan of Mycobacterium leprae, l-alanine of the side chain is replaced by glycine. When expressed in Escherichia coli, MurC (UDP-N-acetyl-muramate:l-alanine ligase) of M. leprae showed Km and Vmax for l-alanine and glycine similar to those of Mycobacterium tuberculosis MurC, suggesting that another explanation should be sought for the presence of glycine.

  20. Activities of UDP-glucuronyltransferase, beta-glucuronidase and deiodinase types I and II in hyper- and hypothyroid rats

    OpenAIRE

    Heide, S.M. van der; Joosten, B.H.G.M.; Everts, M.E.; Klaren, P.H.M.

    2004-01-01

    We have investigated the hypothesis that uridine 5'-diphosphate (UDP)-glucuronyltransferases (UGTs) and beta-glucuronidase are jointly involved in a mechanism for the storage and mobilization of iodothyronine metabolites in liver, kidney, heart and brain. Specifically, we predicted UGT activities to decrease and increase respectively, and beta-glucuronidase activity to increase and decrease respectively in hypo- and hyperthyroidism. To this end we have studied the effects of thyroid status on...

  1. Tomato UDP-Glucose Sterol Glycosyltransferases: A Family of Developmental and Stress Regulated Genes that Encode Cytosolic and Membrane-Associated Forms of the Enzyme

    Directory of Open Access Journals (Sweden)

    Karla Ramirez-Estrada

    2017-06-01

    Full Text Available Sterol glycosyltransferases (SGTs catalyze the glycosylation of the free hydroxyl group at C-3 position of sterols to produce sterol glycosides. Glycosylated sterols and free sterols are primarily located in cell membranes where in combination with other membrane-bound lipids play a key role in modulating their properties and functioning. In contrast to most plant species, those of the genus Solanum contain very high levels of glycosylated sterols, which in the case of tomato may account for more than 85% of the total sterol content. In this study, we report the identification and functional characterization of the four members of the tomato (Solanum lycopersicum cv. Micro-Tom SGT gene family. Expression of recombinant SlSGT proteins in E. coli cells and N. benthamiana leaves demonstrated the ability of the four enzymes to glycosylate different sterol species including cholesterol, brassicasterol, campesterol, stigmasterol, and β-sitosterol, which is consistent with the occurrence in their primary structure of the putative steroid-binding domain found in steroid UDP-glucuronosyltransferases and the UDP-sugar binding domain characteristic for a superfamily of nucleoside diphosphosugar glycosyltransferases. Subcellular localization studies based on fluorescence recovery after photobleaching and cell fractionation analyses revealed that the four tomato SGTs, like the Arabidopsis SGTs UGT80A2 and UGT80B1, localize into the cytosol and the PM, although there are clear differences in their relative distribution between these two cell fractions. The SlSGT genes have specialized but still largely overlapping expression patterns in different organs of tomato plants and throughout the different stages of fruit development and ripening. Moreover, they are differentially regulated in response to biotic and abiotic stress conditions. SlSGT4 expression increases markedly in response to osmotic, salt, and cold stress, as well as upon treatment with abscisic

  2. In vitro characterization of glucuronidation of vanillin: identification of human UDP-glucuronosyltransferases and species differences.

    Science.gov (United States)

    Yu, Jian; Han, Jing-Chun; Hua, Li-Min; Gao, Ya-Jie

    2013-09-01

    Vanillin is a food flavoring agent widely utilized in foods, beverages, drugs, and perfumes and has been demonstrated to exhibit multiple pharmacological activities. Given the importance of glucuronidation in the metabolism of vanillin, the UDP-glucuronosyltransferase conjugation pathway of vanillin was investigated in this study. Vanillin glucuronide was identified by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and a hydrolysis reaction catalyzed by β-glucuronidase. The kinetic study showed that vanillin glucuronidation by HLMs and HIMs followed Michaelis-Menten kinetics and the kinetic parameters were as follows: 134.9 ± 13.5 μM and 81.3 ± 11.3 μM for K(m) of HLMs and HIMs, 63.8 ± 2.0 nmol/min/mg pro and 13.4 ±2.0 nmol/min/mg pro for Vmax of HLMs and HIMs. All UDP-glucuronosyltransferase (UGT) isoforms except UGT1A4, 1A9, and 2B7 showed the capability to glucuronidate vanillin, and UGT1A6 exerted the higher V(max)/K(m) values than other UGT isoforms for the glucuronidation of vanillin when assuming expression of isoforms is similar in recombinant UGTs. Kinetic analysis using liver microsomes from six studied speices indicated that vanillin had highest affinity for the monkey liver microsomes enzyme (K(m)  = 25.6 ± 3.2 μM) and the lowest affinity for the mice liver microsomes enzyme (K(m)  = 149.1 ± 18.4 μM), and intrinsic clearance was in the following order: monkey > dog > minipig > mice > rat ~ human. These data collectively provided important information for understanding glucuronidation of vanillin. Copyright © 2012 John Wiley & Sons, Ltd.

  3. Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs)

    International Nuclear Information System (INIS)

    Fang, Zhong-Ze; Cao, Yun-Feng; Hu, Cui-Min; Hong, Mo; Sun, Xiao-Yu; Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Yang, Ling; Sun, Hong-Zhi

    2013-01-01

    The wide utilization of ginseng provides the high risk of herb–drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb–drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb–drug interaction induced by this kind of inhibition, the ginsenoside Rg 3 was selected as an example, and the inhibition kinetic type and parameters (K i ) were determined. Rg 3 competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K i values) were calculated to be 22.6, 7.9, 1.9, and 2.0 μM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg 3 (400 ng/ml (0.5 μM)) after intramuscular injection of 60 mg Rg 3 , the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng–drug interaction. - Highlights: ► Structure-dependent inhibition of ginsenoside towards UDP

  4. Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs)

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhong-Ze [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Cao, Yun-Feng [Key Laboratory of Contraceptives and Devices Research(NPFPC),Shanghai Engineer and Technology Research Center of Reproductive Health Drug and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai 200032 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Hu, Cui-Min [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Hong, Mo; Sun, Xiao-Yu [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Yang, Ling [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian (China); Sun, Hong-Zhi, E-mail: zzfang228@gmail.com [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)

    2013-03-01

    The wide utilization of ginseng provides the high risk of herb–drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb–drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb–drug interaction induced by this kind of inhibition, the ginsenoside Rg{sub 3} was selected as an example, and the inhibition kinetic type and parameters (K{sub i}) were determined. Rg{sub 3} competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K{sub i} values) were calculated to be 22.6, 7.9, 1.9, and 2.0 μM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg{sub 3} (400 ng/ml (0.5 μM)) after intramuscular injection of 60 mg Rg{sub 3}, the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng–drug interaction. - Highlights: ► Structure

  5. Alteration of cell wall polysaccharides through transgenic expression of UDP-Glc 4-epimerase-encoding genes in potato tubers.

    Science.gov (United States)

    Huang, Jie-Hong; Kortstee, Anne; Dees, Dianka C T; Trindade, Luisa M; Schols, Henk A; Gruppen, Harry

    2016-08-01

    Uridine diphosphate (UDP)-glucose 4-epimerase (UGE) catalyzes the conversion of UDP-glucose to UDP-galactose. Cell wall materials from the cv. Kardal (wild-type, background) and two UGE transgenic lines (UGE 45-1 and UGE 51-16) were isolated and fractionated. The galactose (Gal) content (mg/100g tuber) from UGE 45-1 transgenic line was 38% higher than that of wild-type, and resulted in longer pectin side chains. The Gal content present in UGE 51-16 was 17% lower than that of wild-type, although most pectin populations maintained the same level of Gal. Both UGE transgenic lines showed unexpectedly a decrease in acetylation and an increase in methyl-esterification of pectin. Both UGE transgenic lines showed similar proportions of homogalacturonan and rhamnogalacturonan I within pectin backbone as the wild-type, except for the calcium-bound pectin fraction exhibiting relatively less rhamnogalacturonan I. Next to pectin modification, xyloglucan populations from both transgenic lines were altered resulting in different XSGG and XXGG proportion in comparison to wild-type. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Purification, crystallization and preliminary X-ray diffraction studies of UDP-N-acetylglucosamine pyrophosphorylase from Candida albicans

    Energy Technology Data Exchange (ETDEWEB)

    Maruyama, Daisuke; Nishitani, Yuichi; Nonaka, Tsuyoshi; Kita, Akiko [Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Fukami, Takaaki A.; Mio, Toshiyuki; Yamada-Okabe, Hisafumi [Kamakura Research Laboratory, Chugai Pharmaceutical Co. Ltd, 200 Kajiwara, Kamakura, Kanagawa 247-8530 (Japan); Yamada-Okabe, Toshiko [Department of Hygiene, School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa, Yokohama 236-0004 (Japan); Miki, Kunio, E-mail: miki@kuchem.kyoto-u.ac.jp [Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); RIKEN SPring-8 Center at Harima Institute, Koto 1-1-1, Sayocho, Sayo-gun, Hyogo 679-5148 (Japan)

    2006-12-01

    UDP-N-acetylglucosamine pyrophosphorylase was purified and crystallized and X-ray diffraction data were collected to 2.3 Å resolution. UDP-N-acetylglucosamine pyrophosphorylase (UAP) is an essential enzyme in the synthesis of UDP-N-acetylglucosamine. UAP from Candida albicans was purified and crystallized by the sitting-drop vapour-diffusion method. The crystals of the substrate and product complexes both diffract X-rays to beyond 2.3 Å resolution using synchrotron radiation. The crystals of the substrate complex belong to the triclinic space group P1, with unit-cell parameters a = 47.77, b = 62.89, c = 90.60 Å, α = 90.01, β = 97.72, γ = 92.88°, whereas those of the product complex belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 61.95, b = 90.87, c = 94.88 Å.

  7. Species differences in drug glucuronidation: Humanized UDP-glucuronosyltransferase 1 mice and their application for predicting drug glucuronidation and drug-induced toxicity in humans.

    Science.gov (United States)

    Fujiwara, Ryoichi; Yoda, Emiko; Tukey, Robert H

    2018-02-01

    More than 20% of clinically used drugs are glucuronidated by a microsomal enzyme UDP-glucuronosyltransferase (UGT). Inhibition or induction of UGT can result in an increase or decrease in blood drug concentration. To avoid drug-drug interactions and adverse drug reactions in individuals, therefore, it is important to understand whether UGTs are involved in metabolism of drugs and drug candidates. While most of glucuronides are inactive metabolites, acyl-glucuronides that are formed from compounds with a carboxylic acid group can be highly toxic. Animals such as mice and rats are widely used to predict drug metabolism and drug-induced toxicity in humans. However, there are marked species differences in the expression and function of drug-metabolizing enzymes including UGTs. To overcome the species differences, mice in which certain drug-metabolizing enzymes are humanized have been recently developed. Humanized UGT1 (hUGT1) mice were created in 2010 by crossing Ugt1-null mice with human UGT1 transgenic mice in a C57BL/6 background. hUGT1 mice can be promising tools to predict human drug glucuronidation and acyl-glucuronide-associated toxicity. In this review article, studies of drug metabolism and toxicity in the hUGT1 mice are summarized. We further discuss research and strategic directions to advance the understanding of drug glucuronidation in humans. Copyright © 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

  8. An emerging role of pectic rhamnogalacturonanII for cell wall integrity

    OpenAIRE

    Reboul, Rebecca; Tenhaken, Raimund

    2012-01-01

    The plant cell wall is a complex network of different polysaccharides and glycoproteins, showing high diversity in nature. The essential components, tethering cell wall are under debate, as novel mutants challenge established models. The mutant ugd2,3 with a reduced supply of the important wall precursor UDP-glucuronic acid reveals the critical role of the pectic compound rhamnogalacturonanII for cell wall stability. This polymer seems to be more important for cell wall integrity than the pre...

  9. Comparison of inhibition capability of scutellarein and scutellarin towards important liver UDP-glucuronosyltransferase (UGT) isoforms.

    Science.gov (United States)

    Ma, Guang-You; Cao, Yun-Feng; Hu, Cui-Min; Fang, Zhong-Ze; Sun, Xiao-Yu; Hong, Mo; Zhu, Zhi-Tu

    2014-03-01

    Scutellarin is an important bioactive flavonoid extracted from Erigeron breviscapus (Vant.) Hand-Mazz, and scutellarein is the corresponding aglycone of scutellarin. The present study aims to compare the inhibition potential of scutellarin and scutellarein towards several important UDP-glucuronosyltransferase (UGT) isoforms, including UGT1A1, UGT1A6, UGT1A9 and UGT2B7. It was demonstrated that scutellarein exerted stronger inhibition towards the tested UGT isoforms than scutellarin. Furthermore, the inhibition kinetic type and parameters (Ki ) were determined for the scutellarein's inhibition towards these UGT isoforms. Competitive inhibition of scutellarein towards all these UGT isoforms was demonstrated, and the Ki values were calculated to be 0.02, 5.0, 5.8 and 35.9 μM for UGT1A1, 1A6, 1A9 and 2B7, respectively. Using in vivo maximum plasma concentration of scutellarein in rat, the in vitro-in vivo extrapolation was performed to predict in vivo situation, indicating the most possible in vivo adverse effects due to the inhibition of scutellarein towards UGT1A1. All these results remind us to monitor the utilization of scutellarin and scutellarein, and the herbs containing these two components. Copyright © 2013 John Wiley & Sons, Ltd.

  10. UDP-glucuronosyltransferases 1A6 and 1A10 catalyze reduced menadione glucuronidation

    International Nuclear Information System (INIS)

    Nishiyama, Takahito; Ohnuma, Tomokazu; Inoue, Yuu; Kishi, Takehiko; Ogura, Kenichiro; Hiratsuka, Akira

    2008-01-01

    Menadione (2-methyl-1,4-naphthoquine), also known as vitamin K3, has been widely used as a model compound in the field of oxidative stress-related research. The metabolism of menadione has been studied, and it is known that menadione undergoes a two-electron reduction by NAD(P)H:Quinone oxidoreductase 1 (NQO1) after which the reduced form of menadione (2-methyl-1,4-naphthalenediol, menadiol) is glucuronidated and excreted in urine. To investigate which human UDP-glucuronosyltransferase (UGT) isoforms participate in the glucuronidation of menadiol reduced by NQO1 from menadione, we first constructed heterologously expressed NQO1 in Sf9 cells and tested the menadiol glucuronidating activity of 16 human recombinant UGT isoforms. Of the 16 UGT isoforms, UGTs 1A6, 1A7, 1A8, 1A9, and 1A10 catalyzed menadiol glucuronidation, and, of these, UGTs 1A6 and 1A10 catalyzed menadiol glucuronidation at much higher rates than the other UGTs. Menadiol was regioselectively glucuronidated in the manner of 4-position > 1-position by UGTs 1A7, 1A8, 1A9, and 1A10. In contrast to these UGTs, only UGT1A6 exhibited 1-menadiol-preferential glucuronidating activity. The results suggest possible detoxification pathways for quinones via NQO1 reduction followed by UGT glucuronidation

  11. The Inhibition of the Components from Shengmai Injection towards UDP-Glucuronosyltransferase

    Directory of Open Access Journals (Sweden)

    Li-Peng Jiang

    2014-01-01

    Full Text Available The mechanism of shengmai injection- (SMI- related drug-drug interaction remains unclear. Evaluation of the inhibition potential of SMI’s ingredients towards UDP-glucuronosyltransferases (UGTs activity will provide a new insight to understand SMI-related drug-drug interaction. In vitro incubation system to model UGT reaction was used. Recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU glucuronidation and UGT1A4-catalyzed trifluoperazine (TFP glucuronidation reactions were employed to phenotype the inhibition profile of maidong’s components towards the activity of UGT isoforms. Different inhibition potential of maidong’s components towards various UGT isoforms was observed. Based on the inhibition kinetic investigation results, ophiopogonin D (OD noncompetitively inhibited UGT1A6 and competitively inhibited UGT1A8, ophiopogonin D′ (OD′ noncompetitively inhibited UGT1A6 and UGT1A10, and ruscorectal (RU exhibited competitive inhibition towards UGT1A4. The inhibition kinetic parameters were calculated to be 20.6, 40.1, 5.3, 9.0, and 0.02 μM, respectively. In combination with our previous results obtained for the inhibition of UGT isoforms by ginsenosides and wuweizi components, the important SMI ingredients exhibiting strong inhibition towards UGT isoforms were highlighted. All the results obtained in the present study provide a new insight to understand SMI-related drug-drug interaction.

  12. UDP-galactose and acetyl-CoA transporters as Plasmodium multidrug resistance genes.

    Science.gov (United States)

    Lim, Michelle Yi-Xiu; LaMonte, Gregory; Lee, Marcus C S; Reimer, Christin; Tan, Bee Huat; Corey, Victoria; Tjahjadi, Bianca F; Chua, Adeline; Nachon, Marie; Wintjens, René; Gedeck, Peter; Malleret, Benoit; Renia, Laurent; Bonamy, Ghislain M C; Ho, Paul Chi-Lui; Yeung, Bryan K S; Chow, Eric D; Lim, Liting; Fidock, David A; Diagana, Thierry T; Winzeler, Elizabeth A; Bifani, Pablo

    2016-09-19

    A molecular understanding of drug resistance mechanisms enables surveillance of the effectiveness of new antimicrobial therapies during development and deployment in the field. We used conventional drug resistance selection as well as a regime of limiting dilution at early stages of drug treatment to probe two antimalarial imidazolopiperazines, KAF156 and GNF179. The latter approach permits the isolation of low-fitness mutants that might otherwise be out-competed during selection. Whole-genome sequencing of 24 independently derived resistant Plasmodium falciparum clones revealed four parasites with mutations in the known cyclic amine resistance locus (pfcarl) and a further 20 with mutations in two previously unreported P. falciparum drug resistance genes, an acetyl-CoA transporter (pfact) and a UDP-galactose transporter (pfugt). Mutations were validated both in vitro by CRISPR editing in P. falciparum and in vivo by evolution of resistant Plasmodium berghei mutants. Both PfACT and PfUGT were localized to the endoplasmic reticulum by fluorescence microscopy. As mutations in pfact and pfugt conveyed resistance against additional unrelated chemical scaffolds, these genes are probably involved in broad mechanisms of antimalarial drug resistance.

  13. Chirality Influence of Zaltoprofen Towards UDP-Glucuronosyltransferases (UGTs) Inhibition Potential.

    Science.gov (United States)

    Jia, Lin; Hu, Cuimin; Wang, Haina; Liu, Yongzhe; Liu, Xin; Zhang, Yan-Yan; Li, Wei; Wang, Li-Xuan; Cao, Yun-Feng; Fang, Zhong-Ze

    2015-06-01

    Zaltoprofen (ZLT) is a nonsteroidal antiinflammation drug, and has been clinically employed to treat rheumatoid arthritis, osteoarthritis, and other chronic inflammatory pain conditions. The present study aims to investigate the chirality influence of zaltoprofen towards the inhibition potential towards UDP-glucuronosyltransferases (UGTs) isoforms. In vitro a recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU) glucuronidation incubation system was employed to investigate the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT isoforms. The inhibition difference capability was observed for the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT1A8 and UGT2B7, but not for other tested UGT isoforms. (R)-zaltoprofen exhibited noncompetitive inhibition towards UGT1A8 and competitive inhibition towards UGT2B7. The inhibition kinetic parameters were calculated to be 35.3 μM and 19.2 μM for UGT1A8 and UGT2B7. (R)-zaltoprofen and (S)-zaltoprofen exhibited a different inhibition type towards UGT1A7. Based on the reported maximum plasma concentration of (R)-zaltoprofen in vivo, a high drug-drug interaction between (R)-zaltoprofen and the drugs mainly undergoing UGT1A7, UGT1A8, and UGT2B7-catalyzed glucuronidation was indicated. © 2015 Wiley Periodicals, Inc.

  14. UDP-[14C]glucose-labelable polypeptides from pea: Possible components of glucan synthase I activity

    International Nuclear Information System (INIS)

    Ray, P.M.; Dhugga, K.S.; Gallaghar, S.R.

    1989-01-01

    A membrane-bound polypeptide doublet of about 40 kD can be rapidly labeled with UDP-[ 14 C]glucose under the assay conditions for glucan synthase I (GS-I). Label seems covalently bound, and chases when unlabeled UDPG is added; it might represent a covalent intermediate in polysaccharide synthesis. Labeling and GS-I activity show several common features: they co-sediment with Golgi membranes in sucrose gradients; they depend similarly on Mg 2+ or Mn 2+ (not Ca 2+ ); they decrease dramatically from stem apex to base, and are higher in epidermis than internal tissue; they show similar sensitivities to several inhibitors. But the doublet still labels after polysaccharide-synthesizing activity has been destroyed by Triton X-100. The doublet polypeptides might be glucosyl tranferases whose ability to transfer glucose units to a glucan chain is detergent-sensitive, but to accept glucose from UDPG is not; or they might be detergent-insensitive primary glucose acceptors, from which a distinct, detergent-sensitive transferase(s) move(s) these units to glucan chains

  15. Crystal Structure of a UDP-glucose-specific Glycosyltransferase from a Mycobacterium Species

    Energy Technology Data Exchange (ETDEWEB)

    Fulton, Zara; McAlister, Adrian; Wilce, Matthew C.J.; Brammananth, Rajini; Zaker-Tabrizi, Leyla; Perugini, Matthew A.; Bottomley, Stephen P.; Coppel, Ross L.; Crellin, Paul K.; Rossjohn, Jamie; Beddoe, Travis (Monash); (Melbourne)

    2008-10-24

    Glycosyltransferases (GTs) are a large and ubiquitous family of enzymes that specifically transfer sugar moieties to a range of substrates. Mycobacterium tuberculosis contains a large number of GTs, many of which are implicated in cell wall synthesis, yet the majority of these GTs remain poorly characterized. Here, we report the high resolution crystal structures of an essential GT (MAP2569c) from Mycobacterium avium subsp. paratuberculosis (a close homologue of Rv1208 from M. tuberculosis) in its apo- and ligand-bound forms. The structure adopted the GT-A fold and possessed the characteristic DXD motif that coordinated an Mn{sup 2+} ion. Atypical of most GTs characterized to date, MAP2569c exhibited specificity toward the donor substrate, UDP-glucose. The structure of this ligated complex revealed an induced fit binding mechanism and provided a basis for this unique specificity. Collectively, the structural features suggested that MAP2569c may adopt a 'retaining' enzymatic mechanism, which has implications for the classification of other GTs in this large superfamily.

  16. Disturbance of Mammary UDP-Glucuronosyltransferase Represses Estrogen Metabolism and Exacerbates Experimental Breast Cancer.

    Science.gov (United States)

    Zhou, Xueyan; Zheng, Ziqiang; Xu, Chang; Wang, Juan; Min, Mengjun; Zhao, Yun; Wang, Xi; Gong, Yinhan; Yin, Jiale; Guo, Meng; Guo, Dong; Zheng, Junnian; Zhang, Bei; Yin, Xiaoxing

    2017-08-01

    The progression of breast cancer is closely related to the levels of estrogens within the body. UDP-glucuronosyltransferase (UGT) is an important class of phase II metabolizing enzymes, playing a pivotal role in detoxifying steroid hormone. In the present study, we aim at uncovering the potential dysregulation pattern of UGT and its role in estrogen metabolism and in the pathogenesis of breast cancer. Female Sprague-Dawley rats were treated with 100 mg/kg dimethylbenz(a)anthracene (DMBA) to induce breast cancer. Our results showed that the expression and activity of UGT in mammary tissues were downregulated significantly in DMBA rats. Consistent with this, levels of estradiol, 4-hydroxylated estradiol, and 2-hydroxylated estradiol were increased in both mammary tissues and serum, supporting a notable accumulation of toxic estrogen species in the target tissue of breast cancer. In addition, we also observed the decreased cell migration, cell proliferation, and DNA damage in UGT-transfected MCF-7 cells, suggesting a protective role of UGT against estrogen-induced mammary carcinogenesis. Taken together, these results indicated that accumulation of estrogens induced by UGT deficiency is a critical factor to induce the development of breast cancer. UGT contributes to estrogen elimination, and its glucuronidation capacity influences the estrogen signaling pathway and the pathogenesis of breast cancer. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  17. Komunikasi Data Berbasis Protokol UDP pada Sistem Ubiquitous Mobile Sensing Kualitas Sumber Air

    Directory of Open Access Journals (Sweden)

    Yuning Widiarti Darsono

    2016-07-01

    Full Text Available The need for monitoring, effective and efficient control and evaluation of water quality in regional waters Surabaya become a demand for population growth, climate change and variability in the current era of urbanization. The traditional method is done by collecting water samples, test and analyze water in the laboratory has been relatively expensive and do not have the ability to capture real-time data, analysis and information delivery fast in making decisions. On the other hand, the rapid spread in the use of mobile phones in developing countries has increased mobile data management applications. A variety of mobile applications has also increased in recent years. This is because mobile phones cheap, easy to use and can transmit multiple types of information including images and GPS data remotely. In this paper, the author describes a data communication system of  water quality resources based on UDP protocol. This system is called ubiquitous mobile sensing consisting of microcontroller Arduino, water quality sensors, and Android smartphones. It has the ability to detect temperature, dissolved oxygen (DO, pH and electrical conductivity (EC in real time. By using this monitoring system, the data result is expected more accurate, faster and cheaper.

  18. Inhibition of human UDP-glucuronosyltransferase enzymes by lapatinib, pazopanib, regorafenib and sorafenib: Implications for hyperbilirubinemia.

    Science.gov (United States)

    Miners, John O; Chau, Nuy; Rowland, Andrew; Burns, Kushari; McKinnon, Ross A; Mackenzie, Peter I; Tucker, Geoffrey T; Knights, Kathleen M; Kichenadasse, Ganessan

    2017-04-01

    Kinase inhibitors (KIs) are a rapidly expanding class of drugs used primarily for the treatment of cancer. Data relating to the inhibition of UDP-glucuronosyltransferase (UGT) enzymes by KIs is sparse. However, lapatinib (LAP), pazopanib (PAZ), regorafenib (REG) and sorafenib (SOR) have been implicated in the development of hyperbilirubinemia in patients. This study aimed to characterise the role of UGT1A1 inhibition in hyperbilirubinemia and assess the broader potential of these drugs to perpetrate drug-drug interactions arising from UGT enzyme inhibition. Twelve recombinant human UGTs from subfamilies 1A and 2B were screened for inhibition by LAP, PAZ, REG and SOR. IC 50 values for the inhibition of all UGT1A enzymes, except UGT1A3 and UGT1A4, by the four KIs were enzyme identified to date. In vitro-in vivo extrapolation indicates that inhibition of UGT1A1 contributes significantly to the hyperbilirubinemia observed in patients treated with REG and SOR, but not with LAP and PAZ. Inhibition of other UGT1A1 substrates in vivo is likely. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Identification of the mpl gene encoding UDP-N-acetylmuramate: L-alanyl-gamma-D-glutamyl-meso-diaminopimelate ligase in Escherichia coli and its role in recycling of cell wall peptidoglycan.

    Science.gov (United States)

    Mengin-Lecreulx, D; van Heijenoort, J; Park, J T

    1996-01-01

    A gene, mpl, encoding UDP-N-acetylmuramate:L-alanyl-gamma-D-glutamyl-meso-diaminopimelat e ligase was recognized by its amino acid sequence homology with murC as the open reading frame yjfG present at 96 min on the Escherichia coli map. The existence of such an enzymatic activity was predicted from studies indicating that reutilization of the intact tripeptide L-alanyl-gamma-D-glutamyl-meso-diaminopimelate occurred and accounted for well over 30% of new cell wall synthesis. Murein tripeptide ligase activity could be demonstrated in crude extracts, and greatly increased activity was produced when the gene was cloned and expressed under control of the trc promoter. A null mutant totally lacked activity but was viable, showing that the enzyme is not essential for growth. PMID:8808921

  20. Evaluación de ataques UDP Flood utilizando escenarios virtuales como plataforma experimental

    Directory of Open Access Journals (Sweden)

    Deyci Toscano

    2011-07-01

    Full Text Available Los ataques por denegación de servicio (DoS tienen como propósito imposibilitar el acceso a los servicios de una organización durante un periodo indefinido; por lo general, están dirigidos a los servidores de una empresa, para que no puedan ser accedidos por usuarios autorizados. El presente trabajo se enfoca en la evaluación de ataques DoS tipo UDP Flood, utilizando como plataforma de experimentación un entorno virtual de red que permite identificar cómo actúan dichos ataques en la saturación del ancho de banda; para llevarlo a cabo se diseñó e implementó una red híbrida con segmentación WAN, LAN y DMZ que inhabilita el acceso interno y externo a un servicio Web expuesto. Las herramientas evaluadas fueron UPD Unicorn, Longcat Flooder y UDPl.pl Script de Perl; las dos primeras instaladas sobre Windows, y la última, sobre Linux. Para validar está investigación se desarrolló un mecanismo de detección y mitigación de los ataques a nivel del firewall e IDS/IPS, evitando de este modo la saturación de la red. Finalmente, se evaluó el consumo dememoria, CPUy ancho de banda durante el ataque, la detección y la evasión, con el fin de determinar cuál genera mayor impacto. Los resultados demuestran que el mecanismo detecta, controla y mitiga los ataques.

  1. Evaluación de ataques UDP Flood utilizando escenarios virtuales como plataforma experimental

    Directory of Open Access Journals (Sweden)

    Walter Fuertes

    2012-05-01

    Full Text Available Los ataques por denegación de servicio (DoS tienen como propósito imposibilitar el acceso a los servicios de una organización durante un periodo indefinido; por lo general, están dirigidos a los servidores de una empresa, para que no puedan ser accedidos por usuarios autorizados. El presente trabajo se enfoca en la evaluación de ataques DoS tipo UDP Flood, utilizando como plataforma de experimentación un entorno virtual de red que permite identificar cómo actúan dichos ataques en la saturación del ancho de banda; para llevarlo a cabo se diseñó e implementó una red híbrida con segmentación WAN, LAN y DMZ que inhabilita el acceso interno y externo a un servicio Web expuesto. Las herramientas evaluadas fueron UPD Unicorn, Longcat Flooder y UDPl.pl Script de Perl; las dos primeras instaladas sobre Windows, y la última, sobre Linux. Para validar está investigación se desarrolló un mecanismo de detección y mitigación de los ataques a nivel del firewall e IDS/IPS, evitando de este modo la saturación de la red. Finalmente, se evaluó el consumo dememoria, CPUy ancho de banda durante el ataque, la detección y la evasión, con el fin de determinar cuál genera mayor impacto. Los resultados demuestran que el mecanismo detecta, controla y mitiga los ataques. 

  2. Inhibition of UDP-Glucuronosyltransferase (UGT) Isoforms by Arctiin and Arctigenin.

    Science.gov (United States)

    Zhang, Hui; Zhao, Zhenying; Wang, Tao; Wang, Yijia; Cui, Xiao; Zhang, Huijuan; Fang, Zhong-Ze

    2016-07-01

    Arctiin is the major pharmacological ingredient of Fructus Arctii, and arctigenin is the metabolite of arctiin formed via the catalysis of human intestinal bacteria. The present study aims to investigate the inhibition profile of arctiin and arctigenin on important phase II drug-metabolizing enzymes UDP-glucuronosyltransferases (UGTs), indicating the possible herb-drug interaction. In vitro screening experiment showed that 100 μM of arctiin and arctigenin inhibited the activity of UGT1A3, 1A9, 2B7, and 2B15. Homology modeling-based in silico docking of arctiin and arctigenin into the activity cavity of UGT2B15 showed that hydrogen bonds and hydrophobic interactions contributed to the strong binding free energy of arctiin (-8.14 kcal/mol) and arctigenin (-8.43 kcal/mol) with UGT2B15. Inhibition kinetics study showed that arctiin and arctigenin exerted competitive and noncompetitive inhibition toward UGT2B15, respectively. The inhibition kinetic parameters (Ki ) were calculated to be 16.0 and 76.7 μM for the inhibition of UGT2B15 by arctiin and arctigenin, respectively. Based on the plasma concentration of arctiin and arctigenin after administration of 100 mg/kg of arctiin, the [I]/Ki values were calculated to be 0.3 and 0.007 for arctiin and arctigenin, respectively. Based on the inhibition evaluation standard ([I]/Ki   1, high possibility), arctiin might induce drug-drug interaction with medium possibility. Based on these results, clinical monitoring the utilization of Fructus Arctii is very important and necessary. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Characterization of the human UDP-galactose:ceramide galactosyltransferase gene promoter.

    Science.gov (United States)

    Tencomnao, T; Yu, R K; Kapitonov, D

    2001-02-16

    UDP-galactose:ceramide galactosyltransferase (CGT, EC 2.4.1.45) is a key enzyme in the biosynthesis of galactocerebroside, the most abundant glycosphingolipid in the myelin sheath. An 8 kb fragment upstream from the transcription initiation site of CGT gene was isolated from a human genomic DNA library. Primer extension analysis revealed a single transcription initiation site 329 bp upstream from the ATG start codon. Neither a consensus TATA nor a CCAAT box was identified in the proximity to the transcription start site; however, this region contains a high GC content and multiple putative regulatory elements. To investigate the transcriptional regulation of CGT, a series of 5' deletion constructs of the 5'-flanking region were generated and cloned upstream from the luciferase reporter gene. By comparing promoter activity in the human oligodendroglioma (HOG) and human neuroblastoma (LAN-5) cell lines, we found that the CGT promoter functions in a cell type-specific manner. Three positive cis-acting regulatory regions were identified, including a proximal region at -292/-256 which contains the potential binding sites for known transcription factors (TFs) such as Ets and SP1 (GC box), a distal region at -747/-688 comprising a number of binding sites such as the ERE half-site, NF1-like, TGGCA-BP, and CRE, and a third positive cis-acting region distally localized at -1325/-1083 consisting of binding sites for TFs such as nitrogen regulatory, TCF-1, TGGCA-BP, NF-IL6, CF1, bHLH, NF1-like, GATA, and gamma-IRE. A negative cis-acting domain localized in a far distal region at -1594/-1326 was also identified. Our results suggest the presence of both positive and negative cis-regulatory regions essential for the cell-specific expression in the TATA-less promoter of the human CGT gene.

  4. AglM and VNG1048G, Two Haloarchaeal UDP-Glucose Dehydrogenases, Show Different Salt-Related Behaviors

    OpenAIRE

    Kandiba, Lina; Eichler, Jerry

    2016-01-01

    Haloferax volcanii AglM and Halobacterium salinarum VNG1048G are UDP-glucose dehydrogenases involved in N-glycosylation in each species. Despite sharing >60% sequence identity and the ability of VNG1048G to functionally replace AglM in vivo, these proteins behaved differently as salinity changed. Whereas AglM was active in 2–4 M NaCl, VNG1048G lost much of its activity when salinity dropped below 3 M NaCl. To understand the molecular basis of this phenomenon, each protein was examined by s...

  5. A novel deconvolution method for modeling UDP-N-acetyl-D-glucosamine biosynthetic pathways based on 13C mass isotopologue profiles under non-steady-state conditions

    Directory of Open Access Journals (Sweden)

    Belshoff Alex C

    2011-05-01

    Full Text Available Abstract Background Stable isotope tracing is a powerful technique for following the fate of individual atoms through metabolic pathways. Measuring isotopic enrichment in metabolites provides quantitative insights into the biosynthetic network and enables flux analysis as a function of external perturbations. NMR and mass spectrometry are the techniques of choice for global profiling of stable isotope labeling patterns in cellular metabolites. However, meaningful biochemical interpretation of the labeling data requires both quantitative analysis and complex modeling. Here, we demonstrate a novel approach that involved acquiring and modeling the timecourses of 13C isotopologue data for UDP-N-acetyl-D-glucosamine (UDP-GlcNAc synthesized from [U-13C]-glucose in human prostate cancer LnCaP-LN3 cells. UDP-GlcNAc is an activated building block for protein glycosylation, which is an important regulatory mechanism in the development of many prominent human diseases including cancer and diabetes. Results We utilized a stable isotope resolved metabolomics (SIRM approach to determine the timecourse of 13C incorporation from [U-13C]-glucose into UDP-GlcNAc in LnCaP-LN3 cells. 13C Positional isotopomers and isotopologues of UDP-GlcNAc were determined by high resolution NMR and Fourier transform-ion cyclotron resonance-mass spectrometry. A novel simulated annealing/genetic algorithm, called 'Genetic Algorithm for Isotopologues in Metabolic Systems' (GAIMS was developed to find the optimal solutions to a set of simultaneous equations that represent the isotopologue compositions, which is a mixture of isotopomer species. The best model was selected based on information theory. The output comprises the timecourse of the individual labeled species, which was deconvoluted into labeled metabolic units, namely glucose, ribose, acetyl and uracil. The performance of the algorithm was demonstrated by validating the computed fractional 13C enrichment in these subunits

  6. Downregulation of the UDP-arabinomutase gene in switchgrass (Panicum virgatum L. results in increased cell wall lignin while reducing arabinose-glycans

    Directory of Open Access Journals (Sweden)

    Jonathan Duran Willis

    2016-10-01

    Full Text Available Switchgrass (Panicum virgatum L. is a C4 perennial prairie grass and a lignocellulosic biofuels feedstock. Saccharification and biofuel yields are inhibited by the plant cell wall’s natural recalcitrance against enzymatic degradation. Plant hemicellulose polysaccharides such as arabinoxylans structurally support and crosslink other cell wall polymers. Grasses have predominately Type II cell walls that are abundant in arabinoxylan, which comprise nearly 25% of aboveground biomass. A primary component of arabinoxylan synthesis is uridine diphosphate (UDP linked to arabinofuranose (Araf. A family of UDP-arabinopyranose mutase/reversible glycosylated polypeptides (UAM/RGPs catalyze the interconversion between UDP-arabinopyranose (UDP-Arap and UDP-Araf. In switchgrass we knocked down expression of the endogenous PvUAM1 gene via RNAi to investigate its role in cell wall recalcitrance in the feedstock. PvUAM1 encodes a switchgrass homolog of UDP-arabinose mutase, which converts UDP-Arap to UDP-Araf. Each transgenic line contained between one to at least seven T-DNA insertions, resulting in some cases, a 95% reduction of native PvUAM1 transcript in stem internodes. Transgenic plants had increased pigmentation in vascular tissues at nodes, but were otherwise morphologically similar to non-transgenics. There was decreased cell wall-associated arabinose in leaves and stems by over 50%, but there was an increase in cellulose in these organs. In addition, there was a commensurate change in arabinose side chain extension. Cell wall lignin composition was altered with a concurrent increase in lignin content and transcript abundance of lignin biosynthetic genes in mature tillers. Enzymatic saccharification efficiency was unchanged in the transgenic plants relative to the control, but had increased glucose in cell walls. The increased glucose detected in stems and leaves indicates that attenuation of PvUAM1 expression might have downstream effects on starch

  7. Comparison of the inhibitory effects of tolcapone and entacapone against human UDP-glucuronosyltransferases

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Xia [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Southern Medical University, Guangzhou 510515 (China); Wang, Xin-Xin [RSKT Biopharma Inc., Dalian 116023 (China); Hou, Jie [Dalian Medical University, Dalian 116044 (China); Fang, Zhong-Ze [RSKT Biopharma Inc., Dalian 116023 (China); Wu, Jing-Jing [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Southern Medical University, Guangzhou 510515 (China); Cao, Yun-Feng [RSKT Biopharma Inc., Dalian 116023 (China); Liu, Shu-Wen [State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Southern Medical University, Guangzhou 510515 (China); Ge, Guang-Bo, E-mail: geguangbo@dicp.ac.cn [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); State Key Laboratory of Organ Failure Research, Guangdong Provincial Institute of Nephrology, Southern Medical University, Guangzhou 510515 (China); Yang, Ling, E-mail: ylingdicp@gmail.com [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Jiangxi University of Traditional Chinese Medicine, Nanchang 330006 (China)

    2016-06-15

    Tolcapone and entacapone are two potent catechol-O-methyltransferase (COMT) inhibitors with a similar skeleton and displaying similar pharmacological activities. However, entacapone is a very safe drug used widely in the treatment of Parkinson's disease, while tolcapone is only in limited use for Parkinson's patients and needs careful monitoring of hepatic functions due to hepatotoxicity. This study aims to investigate and compare the inhibitory effects of entacapone and tolcapone on human UDP-glucosyltransferases (UGTs), as well as to evaluate the potential risks from the view of drug-drug interactions (DDI). The results demonstrated that both tolcapone and entacapone exhibited inhibitory effects on UGT1A1, UGT1A7, UGT1A9 and UGT1A10. In contrast to entacapone, tolcapone exhibited more potent inhibitory effects on UGT1A1, UGT1A7, and UGT1A10, while their inhibitory potentials against UGT1A9 were comparable. It is noteworthy that the inhibition constants (K{sub i}) of tolcapone and entacapone against bilirubin-O-glucuronidation in human liver microsomes (HLM) are determined as 0.68 μM and 30.82 μM, respectively, which means that the inhibition potency of tolcapone on UGT1A1 mediated bilirubin-O-glucuronidation in HLM is much higher than that of entacapone. Furthermore, the potential risks of tolcapone or entacapone via inhibition of human UGT1A1 were quantitatively predicted by the ratio of the areas under the plasma drug concentration-time curve (AUC). The results indicate that tolcapone may result in significant increase in AUC of bilirubin or the drugs primarily metabolized by UGT1A1, while entacapone is unlikely to cause a significant DDI through inhibition of UGT1A1. - Highlights: • Tolcapone and entacapone exhibited preferential inhibition against UGT1A enzymes. • In contrast to entacapone, tolcapone exhibited more potent inhibitory effects on human UGT1A1, 1 A7 and 1 A10. • Tolcapone may lead to significant increase in AUC of bilirubin.

  8. Role of extrahepatic UDP-glucuronosyltransferase 1A1: Advances in understanding breast milk-induced neonatal hyperbilirubinemia

    International Nuclear Information System (INIS)

    Fujiwara, Ryoichi; Maruo, Yoshihiro; Chen, Shujuan; Tukey, Robert H.

    2015-01-01

    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic circulation have been associated with breast milk-induced jaundice (BMJ), deficiency in UGT1A1 expression is a known cause of BMJ. It is currently believed that unconjugated bilirubin is metabolized mainly in the liver. However, recent findings support the concept that extrahepatic tissues, such as small intestine and skin, contribute to bilirubin glucuronidation during the neonatal period. We will review the recent advances made towards understanding biological and molecular events impacting BMJ, especially regarding the role of extrahepatic UGT1A1 expression. - Highlights: • Breast-feeding can be a factor for the development of neonatal hyperbilirubinemia. • UDP-glucuronosyltransferase (UGT) 1A1 is the sole bilirubin-metabolizing enzyme. • Extrahepatic UGT1A1 plays an important role in bilirubin metabolism. • We discuss the potential mechanism of breast milk-induced neonatal jaundice.

  9. Role of extrahepatic UDP-glucuronosyltransferase 1A1: Advances in understanding breast milk-induced neonatal hyperbilirubinemia

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Ryoichi, E-mail: fujiwarar@pharm.kitasato-u.ac.jp [Department of Pharmaceutics, School of Pharmacy, Kitasato University, Tokyo (Japan); Maruo, Yoshihiro [Department of Pediatrics, Shiga University of Medical Science, Shiga (Japan); Chen, Shujuan [Department of Pharmacology, Laboratory of Environmental Toxicology, University of California at San Diego, La Jolla, CA 92093 (United States); Tukey, Robert H., E-mail: rtukey@ucsd.edu [Department of Pharmacology, Laboratory of Environmental Toxicology, University of California at San Diego, La Jolla, CA 92093 (United States); Department of Chemistry & Biochemistry, Laboratory of Environmental Toxicology, University of California at San Diego, La Jolla, CA 92093 (United States)

    2015-11-15

    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic circulation have been associated with breast milk-induced jaundice (BMJ), deficiency in UGT1A1 expression is a known cause of BMJ. It is currently believed that unconjugated bilirubin is metabolized mainly in the liver. However, recent findings support the concept that extrahepatic tissues, such as small intestine and skin, contribute to bilirubin glucuronidation during the neonatal period. We will review the recent advances made towards understanding biological and molecular events impacting BMJ, especially regarding the role of extrahepatic UGT1A1 expression. - Highlights: • Breast-feeding can be a factor for the development of neonatal hyperbilirubinemia. • UDP-glucuronosyltransferase (UGT) 1A1 is the sole bilirubin-metabolizing enzyme. • Extrahepatic UGT1A1 plays an important role in bilirubin metabolism. • We discuss the potential mechanism of breast milk-induced neonatal jaundice.

  10. Development of Client-Server Application by Using UDP Socket Programming for Remotely Monitoring CNC Machine Environment in Fixture Process

    Directory of Open Access Journals (Sweden)

    Darmawan Darmawan

    2016-08-01

    Full Text Available The use of computer technology in manufacturing industries can improve manufacturing flexibility significantly, especially in manufacturing processes; many software applications have been utilized to improve machining performance. However, none of them has discussed the abilities to perform direct machining. In this paper, an integrated system for remote operation and monitoring of Computer Numerical Control (CNC machines is put into consideration. The integrated system includes computerization, network technology, and improved holding mechanism. The work proposed by this research is mainly on the software development for such integrated system. It uses Java three-dimensional (3D programming and Virtual Reality Modeling Language (VRML at the client side for visualization of machining environment. This research is aimed at developing a control system to remotely operate and monitor a self-reconfiguration fixture mechanism of a CNC milling machine through internet connection and integration of Personal Computer (PC-based CNC controller, a server side, a client side and CNC milling. The performance of the developed system was evaluated by testing with one type of common protocols particularly User Datagram Protocol (UDP.  Using UDP, the developed system requires 3.9 seconds to complete the close clamping, less than 1 second to release the clamping and it can deliver 463 KiloByte.

  11. Association of human liver bilirubin UDP-glucuronyltransferase activity with a polymorphism in the promoter region of the UGT1A1 gene

    NARCIS (Netherlands)

    Raijmakers, MTM; Jansen, PLM; Steegers, EAP; Peters, WHM

    Background/Aims: Gilbert's syndrome is a benign form of a deficiency in bilirubin glucuronidation. It is associated with a homozygous polymorphism, A(TA)(7)TAA instead of A(TA)(6)TAA, in the TATA-box of the promoter region of the bilirubin UDP-glucuronyltransferase gene. In this study the

  12. Role of extrahepatic UDP-glucuronosyltransferase 1A1: Advances in understanding breast milk-induced neonatal hyperbilirubinemia.

    Science.gov (United States)

    Fujiwara, Ryoichi; Maruo, Yoshihiro; Chen, Shujuan; Tukey, Robert H

    2015-11-15

    Newborns commonly develop physiological hyperbilirubinemia (also known as jaundice). With increased bilirubin levels being observed in breast-fed infants, breast-feeding has been recognized as a contributing factor for the development of neonatal hyperbilirubinemia. Bilirubin undergoes selective metabolism by UDP-glucuronosyltransferase (UGT) 1A1 and becomes a water soluble glucuronide. Although several factors such as gestational age, dehydration and weight loss, and increased enterohepatic circulation have been associated with breast milk-induced jaundice (BMJ), deficiency in UGT1A1 expression is a known cause of BMJ. It is currently believed that unconjugated bilirubin is metabolized mainly in the liver. However, recent findings support the concept that extrahepatic tissues, such as small intestine and skin, contribute to bilirubin glucuronidation during the neonatal period. We will review the recent advances made towards understanding biological and molecular events impacting BMJ, especially regarding the role of extrahepatic UGT1A1 expression. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. UDP-N-Acetyl glucosamine pyrophosphorylase as novel target for controlling Aedes aegypti – molecular modeling, docking and simulation studies

    Directory of Open Access Journals (Sweden)

    Bhagath Kumar Palaka

    2014-12-01

    Full Text Available Aedes aegypti is a vector that transmits diseases like dengue fever, chikungunya, and yellow fever. It is distributed in all tropical and subtropical regions of the world. According to WHO reports, 40% of the world’s population is currently at risk for dengue fever. As vaccines are not available for such diseases, controlling mosquito population becomes necessary. Hence, this study aims at UDP-N-acetyl glucosamine pyrophosphorylase of Aedes aegypti (AaUAP, an essential enzyme for chitin metabolim in insects, as a drug target. Structure of AaUAP was predicted and validated using in-silico approach. Further, docking studies were performed using a set of 10 inhibitors out of which NAG9 was found to have good docking score, which was further supported by simulation studies. Hence, we propose that NAG9 can be considered as a potential hit in designing new inhibitors to control Aedes aegypti.

  14. Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene

    Directory of Open Access Journals (Sweden)

    De Deyn PP

    2006-08-01

    Full Text Available Summary Background Arylsulfatase A (ASA-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT. This deficiency is known to lead to a decreased synthesis of galactosylceramide and sulfatide, which should reduce sulfatide storage and improve pathology in ASA-deficient mice. Results ASA-/- CGT+/- mice, however, showed no detectable decrease in sulfatide storage. Neuronal degeneration of cells in the spiral ganglion of the inner ear, however, was decreased. Behavioural tests showed small but clear improvements of the phenotype in ASA-/- CGT+/- mice. Conclusion Thus the reduction of galactosylceramide and sulfatide biosynthesis by genetic means overall causes modest improvements of pathology.

  15. Crystal Structures of Trypanosoma cruzi UDP-Galactopyranose Mutase Implicate Flexibility of the Histidine Loop in Enzyme Activation

    Energy Technology Data Exchange (ETDEWEB)

    Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Sobrado, Pablo; Tanner, John J. (Virginia Tech); (UMC)

    2012-11-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. Here we report crystal structures of the galactofuranose biosynthetic enzyme UDP-galactopyranose mutase (UGM) from T. cruzi, which are the first structures of this enzyme from a protozoan parasite. UGM is an attractive target for drug design because galactofuranose is absent in humans but is an essential component of key glycoproteins and glycolipids in trypanosomatids. Analysis of the enzyme-UDP noncovalent interactions and sequence alignments suggests that substrate recognition is exquisitely conserved among eukaryotic UGMs and distinct from that of bacterial UGMs. This observation has implications for inhibitor design. Activation of the enzyme via reduction of the FAD induces profound conformational changes, including a 2.3 {angstrom} movement of the histidine loop (Gly60-Gly61-His62), rotation and protonation of the imidazole of His62, and cooperative movement of residues located on the si face of the FAD. Interestingly, these changes are substantially different from those described for Aspergillus fumigatus UGM, which is 45% identical to T. cruzi UGM. The importance of Gly61 and His62 for enzymatic activity was studied with the site-directed mutant enzymes G61A, G61P, and H62A. These mutations lower the catalytic efficiency by factors of 10-50, primarily by decreasing k{sub cat}. Considered together, the structural, kinetic, and sequence data suggest that the middle Gly of the histidine loop imparts flexibility that is essential for activation of eukaryotic UGMs. Our results provide new information about UGM biochemistry and suggest a unified strategy for designing inhibitors of UGMs from the eukaryotic pathogens.

  16. Crystal structures of Trypanosoma cruzi UDP-galactopyranose mutase implicate flexibility of the histidine loop in enzyme activation.

    Science.gov (United States)

    Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Sobrado, Pablo; Tanner, John J

    2012-06-19

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. Here we report crystal structures of the galactofuranose biosynthetic enzyme UDP-galactopyranose mutase (UGM) from T. cruzi, which are the first structures of this enzyme from a protozoan parasite. UGM is an attractive target for drug design because galactofuranose is absent in humans but is an essential component of key glycoproteins and glycolipids in trypanosomatids. Analysis of the enzyme-UDP noncovalent interactions and sequence alignments suggests that substrate recognition is exquisitely conserved among eukaryotic UGMs and distinct from that of bacterial UGMs. This observation has implications for inhibitor design. Activation of the enzyme via reduction of the FAD induces profound conformational changes, including a 2.3 Å movement of the histidine loop (Gly60-Gly61-His62), rotation and protonation of the imidazole of His62, and cooperative movement of residues located on the si face of the FAD. Interestingly, these changes are substantially different from those described for Aspergillus fumigatus UGM, which is 45% identical to T. cruzi UGM. The importance of Gly61 and His62 for enzymatic activity was studied with the site-directed mutant enzymes G61A, G61P, and H62A. These mutations lower the catalytic efficiency by factors of 10-50, primarily by decreasing k(cat). Considered together, the structural, kinetic, and sequence data suggest that the middle Gly of the histidine loop imparts flexibility that is essential for activation of eukaryotic UGMs. Our results provide new information about UGM biochemistry and suggest a unified strategy for designing inhibitors of UGMs from the eukaryotic pathogens.

  17. A diet containing the soy phytoestrogen genistein causes infertility in female rats partially deficient in UDP glucuronyltransferase

    International Nuclear Information System (INIS)

    Seppen, Jurgen

    2012-01-01

    Soy beans contain genistein, a natural compound that has estrogenic effects because it binds the estrogen receptor with relatively high affinity. Genistein is therefore the most important environmental estrogen in the human diet. Detoxification of genistein is mediated through conjugation by UDP-glucuronyltransferase 1 and 2 (UGT1 and UGT2) isoenzymes. Gunn rats have a genetic deficiency in UGT1 activity, UGT2 activities are not affected. Because our Gunn rats stopped breeding after the animal chow was changed to a type with much higher soy content, we examined the mechanism behind this soy diet induced infertility. Gunn and control rats were fed diets with and without genistein. In these rats, plasma levels of genistein and metabolites, fertility and reproductive parameters were determined. Enzyme assays showed reduced genistein UGT activity in Gunn rats, as compared to wild type rats. Female Gunn rats were completely infertile on a genistein diet, wild type rats were fertile. Genistein diet caused a persistent estrus, lowered serum progesterone and inhibited development of corpora lutea in Gunn rats. Concentrations of total genistein in Gunn and control rat plasma were identical and within the range observed in humans after soy consumption. However, Gunn rat plasma contained 25% unconjugated genistein, compared to 3.6% in control rats. This study shows that, under conditions of reduced glucuronidation, dietary genistein exhibits a strongly increased estrogenic effect. Because polymorphisms that reduce UGT1 expression are prevalent in the human population, these results suggest a cautionary attitude towards the consumption of large amounts of soy or soy supplements. -- Highlights: ► Gunn rats are partially deficient in detoxification by UDP glucuronyltransferases. ► Female Gunn rats are infertile on a soy containing diet. ► Soy contains genistein, a potent phytoestrogen. ► Inefficient glucuronidation of genistein causes female infertility.

  18. A diet containing the soy phytoestrogen genistein causes infertility in female rats partially deficient in UDP glucuronyltransferase

    Energy Technology Data Exchange (ETDEWEB)

    Seppen, Jurgen, E-mail: j.seppen@amc.uva.nl

    2012-11-01

    Soy beans contain genistein, a natural compound that has estrogenic effects because it binds the estrogen receptor with relatively high affinity. Genistein is therefore the most important environmental estrogen in the human diet. Detoxification of genistein is mediated through conjugation by UDP-glucuronyltransferase 1 and 2 (UGT1 and UGT2) isoenzymes. Gunn rats have a genetic deficiency in UGT1 activity, UGT2 activities are not affected. Because our Gunn rats stopped breeding after the animal chow was changed to a type with much higher soy content, we examined the mechanism behind this soy diet induced infertility. Gunn and control rats were fed diets with and without genistein. In these rats, plasma levels of genistein and metabolites, fertility and reproductive parameters were determined. Enzyme assays showed reduced genistein UGT activity in Gunn rats, as compared to wild type rats. Female Gunn rats were completely infertile on a genistein diet, wild type rats were fertile. Genistein diet caused a persistent estrus, lowered serum progesterone and inhibited development of corpora lutea in Gunn rats. Concentrations of total genistein in Gunn and control rat plasma were identical and within the range observed in humans after soy consumption. However, Gunn rat plasma contained 25% unconjugated genistein, compared to 3.6% in control rats. This study shows that, under conditions of reduced glucuronidation, dietary genistein exhibits a strongly increased estrogenic effect. Because polymorphisms that reduce UGT1 expression are prevalent in the human population, these results suggest a cautionary attitude towards the consumption of large amounts of soy or soy supplements. -- Highlights: ► Gunn rats are partially deficient in detoxification by UDP glucuronyltransferases. ► Female Gunn rats are infertile on a soy containing diet. ► Soy contains genistein, a potent phytoestrogen. ► Inefficient glucuronidation of genistein causes female infertility.

  19. Structural and Functional Studies of WlbA: A Dehydrogenase Involved in the Biosynthesis of 2,3-Diacetamido-2,3-dideoxy-d-mannuronic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Thoden, James B.; Holden, Hazel M. (UW)

    2010-09-08

    2,3-Diacetamido-2,3-dideoxy-D-mannuronic acid (ManNAc3NAcA) is an unusual dideoxy sugar first identified nearly 30 years ago in the lipopolysaccharide of Pseudomonas aeruginosa O:3a,d. It has since been observed in other organisms, including Bordetella pertussis, the causative agent of whooping cough. Five enzymes are required for the biosynthesis of UDP-ManNAc3NAcA starting from UDP-N-acetyl-D-glucosamine. Here we describe a structural study of WlbA, the NAD-dependent dehydrogenase that catalyzes the second step in the pathway, namely, the oxidation of the C-3{prime} hydroxyl group on the UDP-linked sugar to a keto moiety and the reduction of NAD{sup +} to NADH. This enzyme has been shown to use {alpha}-ketoglutarate as an oxidant to regenerate the oxidized dinucleotide. For this investigation, three different crystal structures were determined: the enzyme with bound NAD(H), the enzyme in a complex with NAD(H) and {alpha}-ketoglutarate, and the enzyme in a complex with NAD(H) and its substrate (UDP-N-acetyl-D-glucosaminuronic acid). The tetrameric enzyme assumes an unusual quaternary structure with the dinucleotides positioned quite closely to one another. Both {alpha}-ketoglutarate and the UDP-linked sugar bind in the WlbA active site with their carbon atoms (C-2 and C-3{prime}, respectively) abutting the re face of the cofactor. They are positioned {approx}3 {angstrom} from the nicotinamide C-4. The UDP-linked sugar substrate adopts a highly unusual curved conformation when bound in the WlbA active site cleft. Lys 101 and His 185 most likely play key roles in catalysis.

  20. Inhibitory Effects of Commonly Used Herbal Extracts on UDP-Glucuronosyltransferase 1A4, 1A6, and 1A9 Enzyme Activities

    Science.gov (United States)

    Mohamed, Mohamed-Eslam F.

    2011-01-01

    The aim of this study was to investigate the effect of commonly used botanicals on UDP-glucuronosyltransferase (UGT) 1A4, UGT1A6, and UGT1A9 activities in human liver microsomes. The extracts screened were black cohosh, cranberry, echinacea, garlic, ginkgo, ginseng, milk thistle, saw palmetto, and valerian in addition to the green tea catechin epigallocatechin gallate (EGCG). Formation of trifluoperazine glucuronide, serotonin glucuronide, and mycophenolic acid phenolic glucuronide was used as an index reaction for UGT1A4, UGT1A6, and UGT1A9 activities, respectively, in human liver microsomes. Inhibition potency was expressed as the concentration of the inhibitor at 50% activity (IC50) and the volume in which the dose could be diluted to generate an IC50-equivalent concentration [volume/dose index (VDI)]. Potential inhibitors were EGCG for UGT1A4, milk thistle for both UGT1A6 and UGT1A9, saw palmetto for UGT1A6, and cranberry for UGT1A9. EGCG inhibited UGT1A4 with an IC50 value of (mean ± S.E.) 33.8 ± 3.1 μg/ml. Milk thistle inhibited both UGT1A6 and UGT1A9 with IC50 values of 59.5 ± 3.6 and 33.6 ± 3.1 μg/ml, respectively. Saw palmetto and cranberry weakly inhibited UGT1A6 and UGT1A9, respectively, with IC50 values >100 μg/ml. For each inhibition, VDI was calculated to determine the potential of achieving IC50-equivalent concentrations in vivo. VDI values for inhibitors indicate a potential for inhibition of first-pass glucuronidation of UGT1A4, UGT1A6, and UGT1A9 substrates. These results highlight the possibility of herb-drug interactions through modulation of UGT enzyme activities. Further clinical studies are warranted to investigate the in vivo extent of the observed interactions. PMID:21632963

  1. A high-performance liquid chromatography-based radiometric assay for sucrose-phosphate synthase and other UDP-glucose requiring enzymes

    International Nuclear Information System (INIS)

    Salvucci, M.E.; Crafts-Brandner, S.J.

    1991-01-01

    A method for product analysis that eliminates a problematic step in the radiometric sucrose-phosphate synthase assay is described. The method uses chromatography on a boronate-derivatized high-performance liquid chromatography column to separate the labeled product, [14C]sucrose phosphate, from unreacted uridine 5'-diphosphate-[14C]glucose (UDP-Glc). Direct separation of these compounds eliminates the need for treatment of the reaction mixtures with alkaline phosphatase, thereby avoiding the problem of high background caused by contaminating phosphodiesterase activity in alkaline phosphatase preparations. The method presented in this paper can be applied to many UDP-Glc requiring enzymes; here the authors show its use for determining the activities of sucrose-phosphate synthase, sucrose synthase, and uridine diphosphate-glucose pyrophosphorylase in plant extracts

  2. Cloning, expression and characterization of a mammalian Nudix hydrolase-like enzyme that cleaves the pyrophosphate bond of UDP-glucose.

    OpenAIRE

    Yagi, Toshihiro; Baroja-Fernández, Edurne; Yamamoto, Ryuji; Muñoz, Francisco José; Akazawa, Takashi; Hong, Kyoung Su; Pozueta-Romero, Javier

    2003-01-01

    A distinct UDP-glucose (UDPG) pyrophosphatase (UGPPase, EC 3.6.1.45) has been characterized using pig kidney ( Sus scrofa ). This enzyme hydrolyses UDPG, the precursor molecule of numerous glycosylation reactions in animals, to produce glucose 1-phosphate (G1P) and UMP. Sequence analyses of the purified enzyme revealed that, similar to the case of a nucleotide-sugar hydrolase controlling the intracellular levels of ADP-glucose linked to glycogen biosynthesis in Escherichia coli [Moreno-Bruna,...

  3. Crystal Structures and Small-angle X-ray Scattering Analysis of UDP-galactopyranose Mutase from the Pathogenic Fungus Aspergillus fumigatus

    Energy Technology Data Exchange (ETDEWEB)

    Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Karr, Dale B.; Nix, Jay C.; Sobrado, Pablo; Tanner, John J. (LBNL); (Missouri); (VPI)

    2015-10-15

    UDP-galactopyranose mutase (UGM) is a flavoenzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose, which is a central reaction in galactofuranose biosynthesis. Galactofuranose has never been found in humans but is an essential building block of the cell wall and extracellular matrix of many bacteria, fungi, and protozoa. The importance of UGM for the viability of many pathogens and its absence in humans make UGM a potential drug target. Here we report the first crystal structures and small-angle x-ray scattering data for UGM from the fungus Aspergillus fumigatus, the causative agent of aspergillosis. The structures reveal that Aspergillus UGM has several extra secondary and tertiary structural elements that are not found in bacterial UGMs yet are important for substrate recognition and oligomerization. Small-angle x-ray scattering data show that Aspergillus UGM forms a tetramer in solution, which is unprecedented for UGMs. The binding of UDP or the substrate induces profound conformational changes in the enzyme. Two loops on opposite sides of the active site move toward each other by over 10 {angstrom} to cover the substrate and create a closed active site. The degree of substrate-induced conformational change exceeds that of bacterial UGMs and is a direct consequence of the unique quaternary structure of Aspergillus UGM. Galactopyranose binds at the re face of the FAD isoalloxazine with the anomeric carbon atom poised for nucleophilic attack by the FAD N5 atom. The structural data provide new insight into substrate recognition and the catalytic mechanism and thus will aid inhibitor design.

  4. Synthesis of a Benzene-containing C1-Phosphonate Analogue of UDP-GlcNAc for the Inhibition of O-GlcNAc Transferase

    Energy Technology Data Exchange (ETDEWEB)

    Im, Jungkyun [Soonchunhyang Univ., Asan (Korea, Republic of)

    2016-01-15

    I report here the design, synthesis, and biological evaluation of a new C1-phosphonate analogue of UDP-GlcNAc as a potential inhibitor of OGT, an enzyme responsible for O-GlcNAc modification. The analogue was designed to mimic the transition state of the natural donor involved in the enzymatic reaction. However, the analogue showed somehow low activity as an inhibitor of OGT.

  5. Purification, crystallization and preliminary X-ray analysis of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC).

    Science.gov (United States)

    Deva, Taru; Pryor, KellyAnn D; Leiting, Barbara; Baker, Edward N; Smith, Clyde A

    2003-08-01

    UDP-N-acetylmuramoyl:L-alanine ligase (MurC) is involved in the pathway leading from UDP-N-glucosamine to the UDP-N-acetylmuramoyl:pentapeptide unit, which is the building block for the peptidoglycan layer found in all bacterial cell walls. The pathways leading to the biosynthesis of the peptidoglycan layer are important targets for the development of novel antibiotics, since animal cells do not contain these pathways. MurC is the first of four similar ATP-dependent amide-bond ligases which share primary and tertiary structural similarities. The crystal structures of three of these have been determined by X-ray crystallography, giving insights into the binding of the carbohydrate substrate and the ATP. Diffraction-quality crystals of the enzyme MurC have been obtained in both native and selenomethionine forms and X-ray diffraction data have been collected at the Se edge at a synchrotron source. The crystals are orthorhombic, with unit-cell parameters a = 73.9, b = 93.6, c = 176.8 A, and diffraction has been observed to 2.6 A resolution.

  6. Drug-Drug Interactions Potential of Icariin and Its Intestinal Metabolites via Inhibition of Intestinal UDP-Glucuronosyltransferases

    Directory of Open Access Journals (Sweden)

    Yun-Feng Cao

    2012-01-01

    Full Text Available Icariin is known as an indicative constituent of the Epimedium genus, which has been commonly used in Chinese herbal medicine to enhance treat impotence and improve sexual function, as well as for several other indications for over 2000 years. In this study, we aimed to investigate the effects of icariin and its intestinal metabolites on the activities of human UDP-glucuronosyltransferase (UGT activities. Using a panel of recombinant human UGT isoforms, we found that icariin exhibited potent inhibition against UGT1A3. It is interesting that the intestinal metabolites of icariin exhibited a different inhibition profile compared with icariin. Different from icariin, icariside II was a potent inhibitor of UGT1A4, UGT1A7, UGT1A9, and UGT2B7, and icaritin was a potent inhibitor of UGT1A7 and UGT1A9. The potential for drug interactions in vivo was also quantitatively predicted and compared. The quantitative prediction of risks indicated that in vivo inhibition against intestinal UGT1A3, UGT1A4, and UGT1A7 would likely occur after oral administration of icariin products.

  7. Transgenic Wheat Expressing a Barley UDP-Glucosyltransferase Detoxifies Deoxynivalenol and Provides High Levels of Resistance to Fusarium graminearum.

    Science.gov (United States)

    Li, Xin; Shin, Sanghyun; Heinen, Shane; Dill-Macky, Ruth; Berthiller, Franz; Nersesian, Natalya; Clemente, Thomas; McCormick, Susan; Muehlbauer, Gary J

    2015-11-01

    Fusarium head blight (FHB), mainly caused by Fusarium graminearum, is a devastating disease of wheat that results in economic losses worldwide. During infection, F. graminearum produces trichothecene mycotoxins, including deoxynivalenol (DON), that increase fungal virulence and reduce grain quality. Transgenic wheat expressing a barley UDP-glucosyltransferase (HvUGT13248) were developed and evaluated for FHB resistance, DON accumulation, and the ability to metabolize DON to the less toxic DON-3-O-glucoside (D3G). Point-inoculation tests in the greenhouse showed that transgenic wheat carrying HvUGT13248 exhibited significantly higher resistance to disease spread in the spike (type II resistance) compared with nontransformed controls. Two transgenic events displayed complete suppression of disease spread in the spikes. Expression of HvUGT13248 in transgenic wheat rapidly and efficiently conjugated DON to D3G, suggesting that the enzymatic rate of DON detoxification translates to type II resistance. Under field conditions, FHB severity was variable; nonetheless, transgenic events showed significantly less-severe disease phenotypes compared with the nontransformed controls. In addition, a seedling assay demonstrated that the transformed plants had a higher tolerance to DON-inhibited root growth than nontransformed plants. These results demonstrate the utility of detoxifying DON as a FHB control strategy in wheat.

  8. Una variedad genética de la UDP-glucuronosil transferasa asociada a toxicidad gastrointestinal por irinotecan A prevalent genetic variety of UDP-glycuronosyl transferase predicts high risk of irinotecan toxicity

    Directory of Open Access Journals (Sweden)

    Matías Valsecchi

    2007-02-01

    Full Text Available Los avances en genética y biología molecular han impulsado la aparición de nuevas áreas de estudio en la medicina, como la farmacogenómica, la cual intenta predecir la respuesta y toxicidad a drogas en función de la variabilidad genética de cada individuo, constituyendo los llamados síndromes fármacogenómicos. La oncología podría beneficiarse debido a la gran toxicidad de sus fármacos. Hay varios loci genéticos que se están analizando por su potencial valor predictivo y hasta ahora sólo tres de ellos demostraron cierto grado de utilidad clínica. En especial, el estudio del número de repeticiones del dinucleótido timina-adenina (TA en el promotor de la enzima UDP-glucuronosil-transferasa (UGT mostró ser capaz de predecir neutropenia severa en pacientes expuestos a dosis intermedias y altas de irinotecan. Comunicamos el caso de una paciente con cáncer de pulmón de células pequeñas que padeció toxicidad hematológica y gastrointestinal grave tras haber sido tratada con dosis relativamente bajas (65 mg/m² de irinotecan, y en quien un análisis del ADN leucocitario mostró la presencia de homocigosis para siete repeticiones de TA. Este caso es un ejemplo de aplicabilidad clínica del test, se discute su utilidad como predictor de toxicidad y la conducta a tomar frente a pacientes con estas características.The advances in genetics and molecular biology have raised new areas in medicine, such as pharmacogenomics, which tries to predict drug responses and toxicities based on the individual genetic variability, describing the so called: pharmacogenomic syndromes. Oncology would find this development extremely useful because of the severe toxicity of chemotherapy. There are a lot of genetic loci under investigation for their potential in predicting drug toxicity, but only three of them have showed clinical usefulness up to now. In particular, quantification of the number of thymine-adenine (TA dinucleotics in the promoter region

  9. Microbial production of hyaluronic acid: current state, challenges, and perspectives

    Directory of Open Access Journals (Sweden)

    Liu Long

    2011-11-01

    Full Text Available Abstract Hyaluronic acid (HA is a natural and linear polymer composed of repeating disaccharide units of β-1, 3-N-acetyl glucosamine and β-1, 4-glucuronic acid with a molecular weight up to 6 million Daltons. With excellent viscoelasticity, high moisture retention capacity, and high biocompatibility, HA finds a wide-range of applications in medicine, cosmetics, and nutraceuticals. Traditionally HA was extracted from rooster combs, and now it is mainly produced via streptococcal fermentation. Recently the production of HA via recombinant systems has received increasing interest due to the avoidance of potential toxins. This work summarizes the research history and current commercial market of HA, and then deeply analyzes the current state of microbial production of HA by Streptococcus zooepidemicus and recombinant systems, and finally discusses the challenges facing microbial HA production and proposes several research outlines to meet the challenges.

  10. Comparison of the inhibition potentials of icotinib and erlotinib against human UDP-glucuronosyltransferase 1A1

    Directory of Open Access Journals (Sweden)

    Xuewei Cheng

    2017-11-01

    Full Text Available UDP-glucuronosyltransferase 1A1 (UGT1A1 plays a key role in detoxification of many potentially harmful compounds and drugs. UGT1A1 inhibition may bring risks of drug–drug interactions (DDIs, hyperbilirubinemia and drug-induced liver injury. This study aimed to investigate and compare the inhibitory effects of icotinib and erlotinib against UGT1A1, as well as to evaluate their potential DDI risks via UGT1A1 inhibition. The results demonstrated that both icotinib and erlotinib are UGT1A1 inhibitors, but the inhibitory effect of icotinib on UGT1A1 is weaker than that of erlotinib. The IC50 values of icotinib and erlotinib against UGT1A1-mediated NCHN-O-glucuronidation in human liver microsomes (HLMs were 5.15 and 0.68 μmol/L, respectively. Inhibition kinetic analyses demonstrated that both icotinib and erlotinib were non-competitive inhibitors against UGT1A1-mediated glucuronidation of NCHN in HLMs, with the Ki values of 8.55 and 1.23 μmol/L, respectively. Furthermore, their potential DDI risks via UGT1A1 inhibition were quantitatively predicted by the ratio of the areas under the concentration–time curve (AUC of NCHN. These findings are helpful for the medicinal chemists to design and develop next generation tyrosine kinase inhibitors with improved safety, as well as to guide reasonable applications of icotinib and erlotinib in clinic, especially for avoiding their potential DDI risks via UGT1A1 inhibition.

  11. Comparison of the inhibition potentials of icotinib and erlotinib against human UDP-glucuronosyltransferase 1A1.

    Science.gov (United States)

    Cheng, Xuewei; Lv, Xia; Qu, Hengyan; Li, Dandan; Hu, Mengmeng; Guo, Wenzhi; Ge, Guangbo; Dong, Ruihua

    2017-11-01

    UDP-glucuronosyltransferase 1A1 (UGT1A1) plays a key role in detoxification of many potentially harmful compounds and drugs. UGT1A1 inhibition may bring risks of drug-drug interactions (DDIs), hyperbilirubinemia and drug-induced liver injury. This study aimed to investigate and compare the inhibitory effects of icotinib and erlotinib against UGT1A1, as well as to evaluate their potential DDI risks via UGT1A1 inhibition. The results demonstrated that both icotinib and erlotinib are UGT1A1 inhibitors, but the inhibitory effect of icotinib on UGT1A1 is weaker than that of erlotinib. The IC 50 values of icotinib and erlotinib against UGT1A1-mediated NCHN- O -glucuronidation in human liver microsomes (HLMs) were 5.15 and 0.68 μmol/L, respectively. Inhibition kinetic analyses demonstrated that both icotinib and erlotinib were non-competitive inhibitors against UGT1A1-mediated glucuronidation of NCHN in HLMs, with the K i values of 8.55 and 1.23 μmol/L, respectively. Furthermore, their potential DDI risks via UGT1A1 inhibition were quantitatively predicted by the ratio of the areas under the concentration-time curve (AUC) of NCHN. These findings are helpful for the medicinal chemists to design and develop next generation tyrosine kinase inhibitors with improved safety, as well as to guide reasonable applications of icotinib and erlotinib in clinic, especially for avoiding their potential DDI risks via UGT1A1 inhibition.

  12. UDP-glucuronosyltransferase and sulfotransferase polymorphisms, sex hormone concentrations, and tumor receptor status in breast cancer patients

    International Nuclear Information System (INIS)

    Sparks, Rachel; Yuan, Xiaopu; Lin, Ming Gang; McVarish, Lynda; Aiello, Erin J; McTiernan, Anne; Ulrich, Cornelia M; Bigler, Jeannette; Tworoger, Shelley S; Yasui, Yutaka; Rajan, Kumar B; Porter, Peggy; Stanczyk, Frank Z; Ballard-Barbash, Rachel

    2004-01-01

    UDP-glucuronosyltransferase (UGT) and sulfotransferase (SULT) enzymes are involved in removing sex hormones from circulation. Polymorphic variation in five UGT and SULT genes – UGT1A1 ((TA) 6 /(TA) 7 ), UGT2B4 (Asp 458 Glu), UGT2B7 (His 268 Tyr), UGT2B15 (Asp 85 Tyr), and SULT1A1 (Arg 213 His) – may be associated with circulating sex hormone concentrations, or the risk of an estrogen receptor-negative (ER - ) or progesterone receptor-negative (PR - ) tumor. Logistic regression analysis was used to estimate the odds ratios of an ER - or PR - tumor associated with polymorphisms in the genes listed above for 163 breast cancer patients from a population-based cohort study of women in western Washington. Adjusted geometric mean estradiol, estrone, and testosterone concentrations were calculated within each UGT and SULT genotype for a subpopulation of postmenopausal breast cancer patients not on hormone therapy 2–3 years after diagnosis (n = 89). The variant allele of UGT1A1 was associated with reduced risk of an ER - tumor (P for trend = 0.03), and variants of UGT2B15 and SULT1A1 were associated with non-statistically significant risk reductions. There was some indication that plasma estradiol and testosterone concentrations varied by UGT2B15 and SULT1A1 genotypes; women with the UGT2B15 Asp/Tyr and Tyr/Tyr genotypes had higher concentrations of estradiol than women with the Asp/Asp genotype (P = 0.004). Compared with women with the SULT1A1 Arg/Arg and Arg/His genotypes, women with the His/His genotype had elevated concentrations of testosterone (P = 0.003). The risk of ER - breast cancer tumors may vary by UGT or SULT genotype. Further, plasma estradiol and testosterone concentrations in breast cancer patients may differ depending on some UGT and SULT genotypes

  13. Cooperation of NAD(P)H:quinone oxidoreductase 1 and UDP-glucuronosyltransferases reduces menadione cytotoxicity in HEK293 cells.

    Science.gov (United States)

    Nishiyama, Takahito; Izawa, Tadashi; Usami, Mami; Ohnuma, Tomokazu; Ogura, Kenichiro; Hiratsuka, Akira

    2010-04-09

    Previous studies have shown that NAD(P)H:quinone oxidoreductase 1 (NQO1) plays an important role in the detoxification of menadione (2-methyl-1,4-naphthoquinone, also known as vitamin K3). However, menadiol (2-methyl-1,4-naphthalenediol) formed from menadione by NQO1-mediated reduction continues to be an unstable substance, which undergoes the reformation of menadione with concomitant formation of reactive oxygen species (ROS). Hence, we focused on the roles of phase II enzymes, with particular attention to UDP-glucuronosyltransferases (UGTs), in the detoxification process of menadione. In this study, we established an HEK293 cell line stably expressing NQO1 (HEK293/NQO1) and HEK293/NQO1 cell lines with doxycycline (DOX)-regulated expression of UGT1A6 (HEK293/NQO1/UGT1A6) and UGT1A10 (HEK293/NQO1/UGT1A10), and evaluated the role of NQO1 and UGTs against menadione-induced cytotoxicity. Our results differed from those of previous studies. HEK293/NQO1 was the most sensitive cell line to menadione cytotoxicity among cell lines established in this study. These phenomena were also observed in HEK293/NQO1/UGT1A6 and HEK293/NQO1/UGT1A10 cells in which the expression of UGT was suppressed by DOX treatment. On the contrary, HEK293/NQO1/UGT1A6 and HEK293/NQO1/UGT1A10 cells without DOX treatment were resistant to menadione-induced cytotoxicity. These results demonstrated that NQO1 is not a detoxification enzyme for menadione and that UGT-mediated glucuronidation of menadiol is the most important detoxification process. Copyright 2009 Elsevier Inc. All rights reserved.

  14. Androgen receptor signals regulate UDP-glucuronosyltransferases in the urinary bladder: a potential mechanism of androgen-induced bladder carcinogenesis.

    Science.gov (United States)

    Izumi, Koji; Zheng, Yichun; Hsu, Jong-Wei; Chang, Chawnshang; Miyamoto, Hiroshi

    2013-02-01

    UDP-glucuronosyltransferases (UGTs), major phase II drug metabolism enzymes, play an important role in urinary bladder cancer initiation by detoxifying carcinogens. We aimed to determine if androgens regulate UGT expression via the androgen receptor (AR) pathway in the bladder. Real-time reverse transcription-polymerase chain reaction and Western blot analyses were used to assess UGT1A levels in the normal urothelium SVHUC cell line stably expressed with AR and in bladder tissues from AR knockout (ARKO) and castrated male mice. Immunohistochemistry was also performed in radical cystectomy specimens. Dihydrotestosterone (DHT) treatment in SVHUC-AR reduced mRNA expression of all the UGT1A subtypes (19-75% decrease), and hydroxyflutamide antagonized the DHT effects. In contrast, DHT showed only marginal effects on UGT1A expression in SVHUC-Vector. Of note were higher expression levels of UGT1As in SVHUC-Vector than in SVHUC-AR. In ARKO mice, all the Ugt1a subtypes were up-regulated, compared to wild-type littermates. In wild-type male mice, castration increased the expression of Ugt1a8, Ugt1a9, and Ugt1a10. Additionally, wild-type female mice had higher levels of Ugt1a than wild-type males. Immunohistochemical studies showed strong (3+) UGT1A staining in 11/24 (46%) cancer tissues, which was significantly lower than in corresponding benign tissues [17/18 (94%) cases (P = 0.0009)]. These results suggest that androgen-mediated AR signals promote bladder carcinogenesis by down-regulating the expression of UGTs in the bladder. Copyright © 2011 Wiley Periodicals, Inc.

  15. Characterization of UGT716A1 as a Multi-substrate UDP:Flavonoid Glucosyltransferase Gene in Ginkgo biloba

    Directory of Open Access Journals (Sweden)

    Xiaojia Su

    2017-12-01

    Full Text Available Ginkgo biloba L., a “living fossil” and medicinal plant, is a well-known rich source of bioactive flavonoids. The molecular mechanism underlying the biosynthesis of flavonoid glucosides, the predominant flavonoids in G. biloba, remains unclear. To better understand flavonoid glucosylation in G. biloba, we generated a transcriptomic dataset of G. biloba leaf tissue by high-throughput RNA sequencing. We identified 25 putative UDP-glycosyltransferase (UGT unigenes that are potentially involved in the flavonoid glycosylation. Among them, we successfully isolated and expressed eight UGT genes in Escherichia coli, and found that recombinant UGT716A1 protein was active toward broad range of flavonoid/phenylpropanoid substrates. In particular, we discovered the first recombinant UGT protein, UGT716A1 from G. biloba, possessing unique activity toward flavanol gallates that have been extensively documented to have significant bioactivity relating to human health. UGT716A1 expression level paralleled the flavonoid distribution pattern in G. biloba. Ectopic over-expression of UGT716A1 in Arabidopsis thaliana led to increased accumulation of several flavonol glucosides. Identification and comparison of the in vitro enzymatic activity of UGT716A1 homologs revealed a UGT from the primitive land species Physcomitrella patens also showed broader substrate spectrum than those from higher plants A. thaliana, Vitis vinifera, and Medicago truncatula. The characterization of UGT716A1 from G. biloba bridges a gap in the evolutionary history of UGTs in gymnosperms. We also discuss the implication of UGT716A1 for biosynthesis, evolution, and bioengineering of diverse glucosylated flavonoids.

  16. Phenobarbital induction and chemical synergism demonstrate the role of UDP-glucuronosyltransferases in detoxification of naphthalophos by Haemonchus contortus larvae.

    Science.gov (United States)

    Kotze, Andrew C; Ruffell, Angela P; Ingham, Aaron B

    2014-12-01

    We used an enzyme induction approach to study the role of detoxification enzymes in the interaction of the anthelmintic compound naphthalophos with Haemonchus contortus larvae. Larvae were treated with the barbiturate phenobarbital, which is known to induce the activity of a number of detoxification enzymes in mammals and insects, including cytochromes P450 (CYPs), UDP-glucuronosyltransferases (UDPGTs), and glutathione (GSH) S-transferases (GSTs). Cotreatment of larvae with phenobarbital and naphthalophos resulted in a significant increase in the naphthalophos 50% inhibitory concentration (IC50) compared to treatment of larvae with the anthelmintic alone (up to a 28-fold increase). The phenobarbital-induced drug tolerance was reversed by cotreatment with the UDPGT inhibitors 5-nitrouracil, 4,6-dihydroxy-5-nitropyrimidine, probenecid, and sulfinpyrazone. Isobologram analysis of the interaction of 5-nitrouracil with naphthalophos in phenobarbital-treated larvae clearly showed the presence of strong synergism. The UDPGT inhibitors 5-nitrouracil, 4,6-dihydroxy-5-nitropyrimidine, and probenecid also showed synergistic effects with non-phenobarbital-treated worms (synergism ratio up to 3.2-fold). This study indicates that H. contortus larvae possess one or more UDPGT enzymes able to detoxify naphthalophos. In highlighting the protective role of this enzyme group, this study reveals the potential for UDPGT enzymes to act as a resistance mechanism that may develop under drug selection pressure in field isolates of this species. In addition, the data indicate the potential for a chemotherapeutic approach utilizing inhibitors of UDPGT enzymes as synergists to increase the activity of naphthalophos against parasitic worms and to combat detoxification-mediated drug resistance if it arises in the field. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  17. Identification and biochemical characterization of an Arabidopsis indole-3-acetic acid glucosyltransferase.

    Science.gov (United States)

    Jackson, R G; Lim, E K; Li, Y; Kowalczyk, M; Sandberg, G; Hoggett, J; Ashford, D A; Bowles, D J

    2001-02-09

    Biochemical characterization of recombinant gene products following a phylogenetic analysis of the UDP-glucosyltransferase (UGT) multigene family of Arabidopsis has identified one enzyme (UGT84B1) with high activity toward the plant hormone indole-3-acetic acid (IAA) and three related enzymes (UGT84B2, UGT75B1, and UGT75B2) with trace activities. The identity of the IAA conjugate has been confirmed to be 1-O-indole acetyl glucose ester. A sequence annotated as a UDP-glucose:IAA glucosyltransferase (IAA-UGT) in the Arabidopsis genome and expressed sequence tag data bases given its similarity to the maize iaglu gene sequence showed no activity toward IAA. This study describes the first biochemical analysis of a recombinant IAA-UGT and provides the foundation for future genetic approaches to understand the role of 1-O-indole acetyl glucose ester in Arabidopsis.

  18. Purification, crystallization and preliminary X-ray diffraction studies of a putative UDP-N-acetyl-d-mannosamine dehydrogenase from Pyrococcus horikoshii OT3

    Energy Technology Data Exchange (ETDEWEB)

    Lokanath, Neratur K.; Pampa, Kudigana J.; Kamiya, Toshimi; Kunishima, Naoki, E-mail: kunisima@spring8.or.jp [Advanced Protein Crystallography Research Group, RIKEN SPring-8 Center, Harima Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

    2007-05-01

    A putative UDP-N-acetyl-d-mannosamine dehydrogenase from P. horikoshii OT3 has been crystallized in space group P2{sub 1}, with unit-cell parameters a = 80.28, b = 69.24, c = 83.10 Å, β = 114.4°. X-ray diffraction data have been collected to 1.80 Å resolution. A putative UDP-N-acetyl-d-mannosamine dehydrogenase from Pyrococcus horikoshii OT3, an essential enzyme for polysaccharide biosynthesis, has been overexpressed in Escherichia coli and purified. Crystals were obtained using the oil-microbatch method at 291 K. A native data set extending to 1.8 Å resolution has been collected and processed in space group P2{sub 1}. Assuming the presence of a dimer in the asymmetric unit, the V{sub M} value is calculated to be 2.3 Å{sup 3} Da{sup −1}, which is consistent with the result of a dynamic light-scattering experiment that shows a dimeric state of the protein in solution.

  19. Identification of three new phase II metabolites of a designer drug methylone formed in rats by N-demethylation followed by conjugation with dicarboxylic acids.

    Science.gov (United States)

    Židková, Monika; Linhart, Igor; Balíková, Marie; Himl, Michal; Dvořáčková, Veronika; Lhotková, Eva; Páleníček, Tomáš

    2018-06-01

    1. Methylone (3,4-methylenedioxy-N-methylcathinone, MDMC), which appeared on the illicit drug market in 2004, is a frequently abused synthetic cathinone derivative. Known metabolic pathways of MDMC include N-demethylation to normethylone (3,4-methylenedioxycathinone, MDC), aliphatic chain hydroxylation and oxidative demethylenation followed by monomethylation and conjugation with glucuronic acid and/or sulphate. 2. Three new phase II metabolites, amidic conjugates of MDC with succinic, glutaric and adipic acid, were identified in the urine of rats dosed subcutaneously with MDMC.HCl (20 mg/kg body weight) by LC-ESI-HRMS using synthetic reference standards to support identification. 3. The main portion of administered MDMC was excreted unchanged. Normethylone, was a major urinary metabolite, of which a minor part was conjugated with dicarboxylic acids. 4. Previously identified ring-opened metabolites 4-hydroxy-3-methoxymethcathinone (4-OH-3-MeO-MC), 3-hydroxy-4-methoxymeth-cathinone (3-OH-4-MeO-MC) and 3,4-dihydroxymethcathinone (3,4-di-OH-MC) mostly in conjugated form with glucuronic and/or sulphuric acids were also detected. 5. Also, ring-opened metabolites derived from MDC, namely, 4-hydroxy-3-methoxycathinone (4-OH-3-MeO-C), 3-hydroxy-4-methoxycathinone (3-OH-4-MeO-C) and 3,4-dihydroxycathinone (3,4-di-OH-C) were identified for the first time in vivo.

  20. Immunomodulating activities of acidic sulphated polysaccharides obtained from the seaweed Ulva rigida C. Agardh.

    Science.gov (United States)

    Leiro, José M; Castro, Rosario; Arranz, Jon A; Lamas, Jesús

    2007-07-01

    Water-soluble acidic polysaccharides from the cell walls of Ulva rigida are mainly composed of disaccharides that contain glucuronic acid and sulphated rhamnose. The structure of disaccharides resembles that of glycosaminoglycans (GAGs) as they both contain glucuronic acid and sulphated sugars. Glycosaminoglycans occur in the extracellular matrix of animal connective tissues but can also be produced by leucocytes at inflammatory sites. Certain types of GAGs can even activate macrophages and therefore the acidic polysaccharides from U. rigida probably modulate macrophage activity. In the present study, we evaluated the effects of U. rigida polysaccharides on several RAW264.7 murine macrophage activities, including expression of inflammatory cytokines and receptors, nitric oxide and prostaglandin E2 (PGE(2)) production, and nitric oxide synthase 2 (NOS-2) and cyclooxygenase-2 (COX-2) gene expression. U. rigida acidic polysaccharides induced a more than two-fold increase in the expression of several chemokines (chemokine (C motif) ligand 1, chemokine (C-X-C motif) ligand 12, chemokine (C-C motif) ligand 22 and chemokine (C-X-C motif) ligand 14 (Cxcl14)) and in the expression of IL6 signal transducer and IL12 receptor beta 1. Incubation of macrophages with U. rigida polysaccharides also induced an increase in nitrite production, although this effect decreased considerably after desulphation of polysaccharides, suggesting that the sulphate group is important for the stimulatory capacity of these molecules. U. rigida polysaccharides also stimulated macrophage secretion of PGE(2) and induced an increase in COX-2 and NOS-2 expression. The results indicate that U. rigida acid polysaccharide can be used as an experimental immunostimulant for analysing inflammatory responses related to macrophage functions. In addition, these polysaccharides may also be of clinical interest for modifying certain macrophage activities in diseases where macrophage function is impaired or needs

  1. Substrate specificities of three members of the human UDP-N-acetyl-alpha-D-galactosamine:Polypeptide N-acetylgalactosaminyltransferase family, GalNAc-T1, -T2, and -T3

    DEFF Research Database (Denmark)

    Wandall, H H; Hassan, H; Mirgorodskaya, E

    1997-01-01

    Mucin-type O-glycosylation is initiated by UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc-transferases). The role each GalNAc-transferase plays in O-glycosylation is unclear. In this report we characterized the specificity and kinetic properties of three purified...

  2. Hexosamines are unlikely to function as a nutrient-sensor in 3T3-L1 adipocytes: a comparison of UDP-hexosamine levels after increased glucose flux and glucosamine treatment.

    NARCIS (Netherlands)

    Bosch, R.R.; Pouwels, M.J.M.; Span, P.N.; Olthaar, A.J.; Tack, C.J.J.; Hermus, A.R.M.M.; Sweep, C.G.J.

    2004-01-01

    Whether the hexosamine biosynthesis pathway acts as a nutrient-sensing pathway is still unclear. Glucose is directed into this pathway by GFAT. Because the activity of GFAT is tightly regulated, we examined whether UDP-hexosamine levels can increase significantly and dose-dependently in response to

  3. Pectin Biosynthesis Is Critical for Cell Wall Integrity and Immunity in Arabidopsis thaliana.

    Science.gov (United States)

    Bethke, Gerit; Thao, Amanda; Xiong, Guangyan; Li, Baohua; Soltis, Nicole E; Hatsugai, Noriyuki; Hillmer, Rachel A; Katagiri, Fumiaki; Kliebenstein, Daniel J; Pauly, Markus; Glazebrook, Jane

    2016-02-01

    Plant cell walls are important barriers against microbial pathogens. Cell walls of Arabidopsis thaliana leaves contain three major types of polysaccharides: cellulose, various hemicelluloses, and pectins. UDP-D-galacturonic acid, the key building block of pectins, is produced from the precursor UDP-D-glucuronic acid by the action of glucuronate 4-epimerases (GAEs). Pseudomonas syringae pv maculicola ES4326 (Pma ES4326) repressed expression of GAE1 and GAE6 in Arabidopsis, and immunity to Pma ES4326 was compromised in gae6 and gae1 gae6 mutant plants. These plants had brittle leaves and cell walls of leaves had less galacturonic acid. Resistance to specific Botrytis cinerea isolates was also compromised in gae1 gae6 double mutant plants. Although oligogalacturonide (OG)-induced immune signaling was unaltered in gae1 gae6 mutant plants, immune signaling induced by a commercial pectinase, macerozyme, was reduced. Macerozyme treatment or infection with B. cinerea released less soluble uronic acid, likely reflecting fewer OGs, from gae1 gae6 cell walls than from wild-type Col-0. Although both OGs and macerozyme-induced immunity to B. cinerea in Col-0, only OGs also induced immunity in gae1 gae6. Pectin is thus an important contributor to plant immunity, and this is due at least in part to the induction of immune responses by soluble pectin, likely OGs, that are released during plant-pathogen interactions. © 2016 American Society of Plant Biologists. All rights reserved.

  4. Vitamin C. Biosynthesis, recycling and degradation in mammals.

    Science.gov (United States)

    Linster, Carole L; Van Schaftingen, Emile

    2007-01-01

    Vitamin C, a reducing agent and antioxidant, is a cofactor in reactions catalyzed by Cu(+)-dependent monooxygenases and Fe(2+)-dependent dioxygenases. It is synthesized, in vertebrates having this capacity, from d-glucuronate. The latter is formed through direct hydrolysis of uridine diphosphate (UDP)-glucuronate by enzyme(s) bound to the endoplasmic reticulum membrane, sharing many properties with, and most likely identical to, UDP-glucuronosyltransferases. Non-glucuronidable xenobiotics (aminopyrine, metyrapone, chloretone and others) stimulate the enzymatic hydrolysis of UDP-glucuronate, accounting for their effect to increase vitamin C formation in vivo. Glucuronate is converted to l-gulonate by aldehyde reductase, an enzyme of the aldo-keto reductase superfamily. l-Gulonate is converted to l-gulonolactone by a lactonase identified as SMP30 or regucalcin, whose absence in mice leads to vitamin C deficiency. The last step in the pathway of vitamin C synthesis is the oxidation of l-gulonolactone to l-ascorbic acid by l-gulonolactone oxidase, an enzyme associated with the endoplasmic reticulum membrane and deficient in man, guinea pig and other species due to mutations in its gene. Another fate of glucuronate is its conversion to d-xylulose in a five-step pathway, the pentose pathway, involving identified oxidoreductases and an unknown decarboxylase. Semidehydroascorbate, a major oxidation product of vitamin C, is reconverted to ascorbate in the cytosol by cytochrome b(5) reductase and thioredoxin reductase in reactions involving NADH and NADPH, respectively. Transmembrane electron transfer systems using ascorbate or NADH as electron donors serve to reduce semidehydroascorbate present in neuroendocrine secretory vesicles and in the extracellular medium. Dehydroascorbate, the fully oxidized form of vitamin C, is reduced spontaneously by glutathione, as well as enzymatically in reactions using glutathione or NADPH. The degradation of vitamin C in mammals is

  5. Real time data acquisition for a time projection chamber using a high speed DEC-RT11 to UNIX UDP-TCP/IP interface

    International Nuclear Information System (INIS)

    Thomas, J.; Douglas, M.; Watanabe, R.; Henrikson, H.E.; Iqbal, M.Z.; Mitchell, L.W.; O'Callaghan, B.M.G.; Wong, H.T.K.; Melvin, J.D.

    1987-01-01

    The authors built a high pressure xenon Time Projection Chamber to study double beta decay, a process of fundamental interest which, if observed, would indicate that the neutrino is a massive Majorana particle. Raw data rates from the TPC exceed 200 Kbytes per second. The TPC is operated through a CAMAC interface with a DEC LSI-11/73 computer networked to a Tektronix 6130 workstation. Data is transmitted at about 15 Kbytes per second although the network is capable of transmitting data at 80 Kbytes per second. The only system level programming required was to write a UDP-TCP/IP driver for the DEC-DEQNA Ethenet board on the 11/73

  6. The Arabidopsis UDP-glycosyltransferases UGT79B2 and UGT79B3, contribute to cold, salt and drought stress tolerance via modulating anthocyanin accumulation.

    Science.gov (United States)

    Li, Pan; Li, Yan-Jie; Zhang, Feng-Ju; Zhang, Gui-Zhi; Jiang, Xiao-Yi; Yu, Hui-Min; Hou, Bing-Kai

    2017-01-01

    The plant family 1 UDP-glycosyltransferases (UGTs) are the biggest GT family in plants, which are responsible for transferring sugar moieties onto a variety of small molecules, and control many metabolic processes; however, their physiological significance in planta is largely unknown. Here, we revealed that two Arabidopsis glycosyltransferase genes, UGT79B2 and UGT79B3, could be strongly induced by various abiotic stresses, including cold, salt and drought stresses. Overexpression of UGT79B2/B3 significantly enhanced plant tolerance to low temperatures as well as drought and salt stresses, whereas the ugt79b2/b3 double mutants generated by RNAi (RNA interference) and CRISPR-Cas9 strategies were more susceptible to adverse conditions. Interestingly, the expression of UGT79B2 and UGT79B3 is directly controlled by CBF1 (CRT/DRE-binding factor 1, also named DREB1B) in response to low temperatures. Furthermore, we identified the enzyme activities of UGT79B2/B3 in adding UDP-rhamnose to cyanidin and cyanidin 3-O-glucoside. Ectopic expression of UGT79B2/B3 significantly increased the anthocyanin accumulation, and enhanced the antioxidant activity in coping with abiotic stresses, whereas the ugt79b2/b3 double mutants showed reduced anthocyanin levels. When overexpressing UGT79B2/B3 in tt18 (transparent testa 18), a mutant that cannot synthesize anthocyanins, both genes fail to improve plant adaptation to stress. Taken together, we demonstrate that UGT79B2 and UGT79B3, identified as anthocyanin rhamnosyltransferases, are regulated by CBF1 and confer abiotic stress tolerance via modulating anthocyanin accumulation. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  7. Molecular cloning and characterization of UDP-glucose: furaneol glucosyltransferase gene from grapevine cultivar Muscat Bailey A (Vitis labrusca × V. vinifera).

    Science.gov (United States)

    Sasaki, Kanako; Takase, Hideki; Kobayashi, Hironori; Matsuo, Hironori; Takata, Ryoji

    2015-10-01

    2,5-Dimethyl-4-hydroxy-3(2H)-furanone (furaneol) is an important aroma compound in fruits, such as pineapple and strawberry, and is reported to contribute to the strawberry-like note in some wines. Several grapevine species are used in winemaking, and furaneol is one of the characteristic aroma compounds in wines made from American grape (Vitis labrusca) and its hybrid grape. Furaneol glucoside was recently isolated as an important furaneol derivative from the hybrid grapevine cultivar, Muscat Bailey A (V. labrusca × V. vinifera), and this was followed by its isolation from some fruits such as strawberry and tomato. Furaneol glucoside is a significant 'aroma precursor of wine' because furaneol is liberated from it during alcoholic fermentation. In this study, a glucosyltransferase gene from Muscat Bailey A (UGT85K14), which is responsible for the glucosylation of furaneol was identified. UGT85K14 was expressed in the representative grape cultivars regardless of species, indicating that furaneol glucoside content is regulated by the biosynthesis of furaneol. On the other hand, furaneol glucoside content in Muscat Bailey A berry during maturation might be controlled by the expression of UGT85K14 along with the biosynthesis of furaneol. Recombinant UGT85K14 expressed in Escherichia coli is able to transfer a glucose moiety from UDP-glucose to the hydroxy group of furaneol, indicating that this gene might be UDP-glucose: furaneol glucosyltransferase in Muscat Bailey A. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  8. Molecular mechanisms for sweet-suppressing effect of gymnemic acids.

    Science.gov (United States)

    Sanematsu, Keisuke; Kusakabe, Yuko; Shigemura, Noriatsu; Hirokawa, Takatsugu; Nakamura, Seiji; Imoto, Toshiaki; Ninomiya, Yuzo

    2014-09-12

    Gymnemic acids are triterpene glycosides that selectively suppress taste responses to various sweet substances in humans but not in mice. This sweet-suppressing effect of gymnemic acids is diminished by rinsing the tongue with γ-cyclodextrin (γ-CD). However, little is known about the molecular mechanisms underlying the sweet-suppressing effect of gymnemic acids and the interaction between gymnemic acids versus sweet taste receptor and/or γ-CD. To investigate whether gymnemic acids directly interact with human (h) sweet receptor hT1R2 + hT1R3, we used the sweet receptor T1R2 + T1R3 assay in transiently transfected HEK293 cells. Similar to previous studies in humans and mice, gymnemic acids (100 μg/ml) inhibited the [Ca(2+)]i responses to sweet compounds in HEK293 cells heterologously expressing hT1R2 + hT1R3 but not in those expressing the mouse (m) sweet receptor mT1R2 + mT1R3. The effect of gymnemic acids rapidly disappeared after rinsing the HEK293 cells with γ-CD. Using mixed species pairings of human and mouse sweet receptor subunits and chimeras, we determined that the transmembrane domain of hT1R3 was mainly required for the sweet-suppressing effect of gymnemic acids. Directed mutagenesis in the transmembrane domain of hT1R3 revealed that the interaction site for gymnemic acids shared the amino acid residues that determined the sensitivity to another sweet antagonist, lactisole. Glucuronic acid, which is the common structure of gymnemic acids, also reduced sensitivity to sweet compounds. In our models, gymnemic acids were predicted to dock to a binding pocket within the transmembrane domain of hT1R3. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Curcumin improves alcoholic fatty liver by inhibiting fatty acid biosynthesis.

    Science.gov (United States)

    Guo, Chang; Ma, Jingfan; Zhong, Qionghong; Zhao, Mengyuan; Hu, Tianxing; Chen, Tong; Qiu, Longxin; Wen, Longping

    2017-08-01

    Alcoholic fatty liver is a threat to human health. It has been long known that abstinence from alcohol is the most effective therapy, other effective therapies are not available for the treatment in humans. Curcumin has a great potential for anti-oxidation and anti-inflammation, but the effect on metabolic reconstruction remains little known. Here we performed metabolomic analysis by gas chromatography/mass spectrometry and explored ethanol pathogenic insight as well as curcumin action pattern. We identified seventy-one metabolites in mouse liver. Carbohydrates and lipids were characteristic categories. Pathway analysis results revealed that ethanol-induced pathways including biosynthesis of unsaturated fatty acids, fatty acid biosynthesis and pentose and glucuronate interconversions were suppressed by curcumin. Additionally, ethanol enhanced galactose metabolism and pentose phosphate pathway. Glyoxylate and dicarboxylate metabolism and pyruvate metabolism were inhibited in mice fed ethanol diet plus curcumin. Stearic acid, oleic acid and linoleic acid were disease biomarkers and therapical biomarkers. These results reflect the landscape of hepatic metabolism regulation. Our findings illustrate ethanol pathological pathway and metabolic mechanism of curcumin therapy. Copyright © 2017. Published by Elsevier Inc.

  10. Albumin stimulates the activity of the human UDP-glucuronosyltransferases 1A7, 1A8, 1A10, 2A1 and 2B15, but the effects are enzyme and substrate dependent.

    Science.gov (United States)

    Manevski, Nenad; Troberg, Johanna; Svaluto-Moreolo, Paolo; Dziedzic, Klaudyna; Yli-Kauhaluoma, Jari; Finel, Moshe

    2013-01-01

    Human UDP-glucuronosyltransferases (UGTs) are important enzymes in metabolic elimination of endo- and xenobiotics. It was recently shown that addition of fatty acid free bovine serum albumin (BSA) significantly enhances in vitro activities of UGTs, a limiting factor in in vitro-in vivo extrapolation. Nevertheless, since only few human UGT enzymes were tested for this phenomenon, we have now performed detailed enzyme kinetic analysis on the BSA effects in six previously untested UGTs, using 2-4 suitable substrates for each enzyme. We also examined some of the previously tested UGTs, but using additional substrates and a lower BSA concentration, only 0.1%. The latter concentration allows the use of important but more lipophilic substrates, such as estradiol and 17-epiestradiol. In five newly tested UGTs, 1A7, 1A8, 1A10, 2A1, and 2B15, the addition of BSA enhanced, to a different degree, the in vitro activity by either decreasing reaction's K(m), increasing its V(max), or both. In contrast, the activities of UGT2B17, another previously untested enzyme, were almost unaffected. The results of the assays with the previously tested UGTs, 1A1, 1A6, 2B4, and 2B7, were similar to the published BSA only as far as the BSA effects on the reactions' K(m) are concerned. In the cases of V(max) values, however, our results differ significantly from the previously published ones, at least with some of the substrates. Hence, the magnitude of the BSA effects appears to be substrate dependent, especially with respect to V(max) increases. Additionally, the BSA effects may be UGT subfamily dependent since K(m) decreases were observed in members of subfamilies 1A, 2A and 2B, whereas large V(max) increases were only found in several UGT1A members. The results shed new light on the complexity of the BSA effects on the activity and enzyme kinetics of the human UGTs.

  11. Albumin stimulates the activity of the human UDP-glucuronosyltransferases 1A7, 1A8, 1A10, 2A1 and 2B15, but the effects are enzyme and substrate dependent.

    Directory of Open Access Journals (Sweden)

    Nenad Manevski

    Full Text Available Human UDP-glucuronosyltransferases (UGTs are important enzymes in metabolic elimination of endo- and xenobiotics. It was recently shown that addition of fatty acid free bovine serum albumin (BSA significantly enhances in vitro activities of UGTs, a limiting factor in in vitro-in vivo extrapolation. Nevertheless, since only few human UGT enzymes were tested for this phenomenon, we have now performed detailed enzyme kinetic analysis on the BSA effects in six previously untested UGTs, using 2-4 suitable substrates for each enzyme. We also examined some of the previously tested UGTs, but using additional substrates and a lower BSA concentration, only 0.1%. The latter concentration allows the use of important but more lipophilic substrates, such as estradiol and 17-epiestradiol. In five newly tested UGTs, 1A7, 1A8, 1A10, 2A1, and 2B15, the addition of BSA enhanced, to a different degree, the in vitro activity by either decreasing reaction's K(m, increasing its V(max, or both. In contrast, the activities of UGT2B17, another previously untested enzyme, were almost unaffected. The results of the assays with the previously tested UGTs, 1A1, 1A6, 2B4, and 2B7, were similar to the published BSA only as far as the BSA effects on the reactions' K(m are concerned. In the cases of V(max values, however, our results differ significantly from the previously published ones, at least with some of the substrates. Hence, the magnitude of the BSA effects appears to be substrate dependent, especially with respect to V(max increases. Additionally, the BSA effects may be UGT subfamily dependent since K(m decreases were observed in members of subfamilies 1A, 2A and 2B, whereas large V(max increases were only found in several UGT1A members. The results shed new light on the complexity of the BSA effects on the activity and enzyme kinetics of the human UGTs.

  12. Promiscuous activity of ER glucosidase II discovered through donor specificity analysis of UGGT

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Atsushi, E-mail: miyagawa.atsushi@nitech.ac.jp [RIKEN Advanced Science Institute, Wako, Saitama 351-0198 (Japan); Department of Materials Science and Engineering, Nagoya Institute of Technology, Showa-Ku, Nagoya 466-8555 (Japan); Totani, Kiichiro [Department of Materials and Life Science, Seikei University, Musashino, Tokyo 180-8633 (Japan); Matsuo, Ichiro [Department of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Ito, Yukishige, E-mail: yukito@riken.jp [RIKEN Advanced Science Institute, Wako, Saitama 351-0198 (Japan); ERATO Japan Science and Technology Agency, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2010-12-17

    Research highlights: {yields} UGGT has a narrow donor specificity. {yields} UGGT gave several non-natural high-mannose-type glycans. {yields} G-II has a promiscuous activity as broad specificity hexosidase. -- Abstract: In glycoprotein quality control system in the endoplasmic reticulum (ER), UGGT (UDP-glucose:glycoprotein glucosyltransferase) and glucosidase II (G-II) play key roles. UGGT serves as a glycoprotein folding sensor by virtue of its unique specificity to glucosylate glycoproteins at incompletely folded stage. By using various UDP-Glc analogues, we first analyzed donor specificity of UGGT, which was proven to be rather narrow. However, marginal activity was observed with UDP-galactose and UDP-glucuronic acid as well as with 3-, 4- and 6-deoxy glucose analogues to give corresponding transfer products. Intriguingly, G-II smoothly converted all of them back to Man{sub 9}GlcNAc{sub 2}, providing an indication that G-II has a promiscuous activity as a broad specificity hexosidase.

  13. Pentavalent Bismuth-Mediated Glycosylation Methods to Activate Sialic and Uronic Acids and the Incorporation of Sialic Acids Into Insulin

    Science.gov (United States)

    Kabotso, Daniel Elorm Kwame

    The negative charge at physiological pH of carboxylic acid-containing monosaccharides modulate the properties of many natural biomolecules such as oligosaccharides and glycoconjugates. Unfortunately, these altered electronic properties also make the incorporation of such acidic sugars more challenging as compared to the more commonly studied neutral sugars. Herein are reported the first demonstration of glycosylation reactions mediated by triphenylbis(1,1,1-trifluoromethanesulfonato)-bismuth with thioglycosides containing carboxylic acid substituents protected as esters. Unlike with many neutral sugar substrates, the addition of 1-propanethiol to the reactions proved critical to obtaining good yields of the desired glycosylation products using sialic acid, galacturonic acid, and glucuronic acid. The protocol was demonstrated to be amenable to automation using a liquid-handling platform. The consequences of artificially incorporating carboxylic-acid-containing sugars into proteins were tested by the design of a linker containing 1 to 4 sialic acids--a sugar found in many human proteins and brain tissues--that was attached via reductive amination of trityl thiopropylaldehyde at the phenyl alanine terminal end of the protein insulin produced through solid-phase peptide synthesis. Removal of the trityl group with neat trifluoroacetic acid furnished the thiol-free modified insulin that was ligated via a disulfide bond to the peptide scaffold bearing acetyl protected sialic acids. A 14-15% ammonium hydroxide solution was found to be effective in deprotecting the acetyl groups without degradation of the disulfide bond. In addition to maintaining the potency and bioactivity of insulin, the sialic acid-containing linker rendered insulin more resistant to aggregation due to heat and mechanical agitation compared to the unmodified protein.

  14. Tyrosine Phosphorylation of the UDP-Glucose Dehydrogenase of Escherichia coli Is at the Crossroads of Colanic Acid Synthesis and Polymyxin Resistance

    DEFF Research Database (Denmark)

    Lacour, S.; Bechet, E.; Cozzone, A.J.

    2008-01-01

    -kinases have been characterized. BY-kinases have been shown to participate in various physiological processes. Nevertheless, we are at a very early stage of defining their importance in the bacterial cell. In Escherichia coli, two BY-kinases, Wzc and Etk, have been characterized biochemically. Wzc has been......Background: In recent years, an idiosyncratic new class of bacterial enzymes, named BY-kinases, has been shown to catalyze protein-tyrosine phosphorylation. These enzymes share no structural and functional similarities with their eukaryotic counterparts and, to date, only few substrates of BY....../Principal Findings: Here, we studied the role of Ugd phosphorylation. We first confirmed in vivo the phosphorylation of Ugd by Wzc and we demonstrated that Ugd is also phosphorylated by Etk, the other BY-kinase identified in E. coli. Tyrosine 71 (Tyr71) was characterized as the Ugd site phosphorylated by both Wzc...

  15. Functional and Biochemical Analysis of Chlamydia trachomatis MurC, an Enzyme Displaying UDP-N-Acetylmuramate:Amino Acid Ligase Activity

    OpenAIRE

    Hesse, Lars; Bostock, Julieanne; Dementin, Sebastien; Blanot, Didier; Mengin-Lecreulx, Dominique; Chopra, Ian

    2003-01-01

    Chlamydiae are unusual obligate intracellular bacteria that cause serious infections in humans. Chlamydiae contain genes that appear to encode products with peptidoglycan biosynthetic activity. The organisms are also susceptible to antibiotics that inhibit peptidoglycan synthesis. However, chlamydiae do not synthesize detectable peptidoglycan. The paradox created by these observations is known as the chlamydial anomaly. The MurC enzyme of chlamydiae, which is synthesized as a bifunctional Mur...

  16. UDP-N-Acetylmuramic Acid l-Alanine Ligase (MurC) Inhibition in a tolC Mutant Escherichia coli Strain Leads to Cell Death

    OpenAIRE

    Humnabadkar, Vaishali; Prabhakar, K. R.; Narayan, Ashwini; Sharma, Sreevalli; Guptha, Supreeth; Manjrekar, Praveena; Chinnapattu, Murugan; Ramachandran, Vasanthi; Hameed, Shahul P.; Ravishankar, Sudha; Chatterji, Monalisa

    2014-01-01

    The Mur ligases play an essential role in the biosynthesis of bacterial peptidoglycan and hence are attractive antibacterial targets. A screen of the AstraZeneca compound library led to the identification of compound A, a pyrazolopyrimidine, as a potent inhibitor of Escherichia coli and Pseudomonas aeruginosa MurC. However, cellular activity against E. coli or P. aeruginosa was not observed. Compound A was active against efflux pump mutants of both strains. Experiments using an E. coli tol...

  17. UDP-N-acetylmuramic acid l-alanine ligase (MurC) inhibition in a tolC mutant Escherichia coli strain leads to cell death.

    Science.gov (United States)

    Humnabadkar, Vaishali; Prabhakar, K R; Narayan, Ashwini; Sharma, Sreevalli; Guptha, Supreeth; Manjrekar, Praveena; Chinnapattu, Murugan; Ramachandran, Vasanthi; Hameed, Shahul P; Ravishankar, Sudha; Chatterji, Monalisa

    2014-10-01

    The Mur ligases play an essential role in the biosynthesis of bacterial peptidoglycan and hence are attractive antibacterial targets. A screen of the AstraZeneca compound library led to the identification of compound A, a pyrazolopyrimidine, as a potent inhibitor of Escherichia coli and Pseudomonas aeruginosa MurC. However, cellular activity against E. coli or P. aeruginosa was not observed. Compound A was active against efflux pump mutants of both strains. Experiments using an E. coli tolC mutant revealed accumulation of the MurC substrate and a decrease in the level of product upon treatment with compound A ,: indicating inhibition of MurC enzyme in these cells. Such a modulation was not observed in the E. coli wild-type cells. Further, overexpression of MurC in the E. coli tolC mutant led to an increase in the compound A MIC by ≥16-fold, establishing a correlation between MurC inhibition and cellular activity. In addition, estimation of the intracellular compound A level showed an accumulation of the compound over time in the tolC mutant strain. A significant compound A level was not detected in the wild-type E. coli strain even upon treatment with high concentrations of the compound. Therefore, the lack of MIC and absence of MurC inhibition in wild-type E. coli were possibly due to suboptimal compound concentration as a consequence of a high efflux level and/or poor permeativity of compound A. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  18. Inhibition of UDP-glucosylceramide synthase in mice prevents Gaucher disease-associated B-cell malignancy

    NARCIS (Netherlands)

    Pavlova, Elena V.; Archer, Joy; Wang, Susan; Dekker, Nick; Aerts, Johannes Mfg; Karlsson, Stefan; Cox, Timothy M.

    2015-01-01

    Clonal B-cell proliferation is a frequent manifestation of Gaucher disease - a sphingolipidosis associated with a high risk of multiple myeloma and non-Hodgkin lymphoma. Gaucher disease is caused by genetic deficiency of acid β-glucosidase, the natural substrates of which (β-d-glucosylceramide and

  19. Herb-drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7.

    Science.gov (United States)

    Ma, Hai-Ying; Sun, Dong-Xue; Cao, Yun-Feng; Ai, Chun-Zhi; Qu, Yan-Qing; Hu, Cui-Min; Jiang, Changtao; Dong, Pei-Pei; Sun, Xiao-Yu; Hong, Mo; Tanaka, Naoki; Gonzalez, Frank J; Ma, Xiao-Chi; Fang, Zhong-Ze

    2014-05-15

    Herb-drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (Ki) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (Ki) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb-drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Functional and Evolutionary Characterization of a UDP-Xylose Synthase Gene from the Plant Pathogen Xylella fastidiosa, Involved in the Synthesis of Bacterial Lipopolysaccharide.

    Science.gov (United States)

    Alencar, Valquíria Campos; Jabes, Daniela Leite; Menegidio, Fabiano Bezerra; Sassaki, Guilherme Lanzi; de Souza, Lucas Rodrigo; Puzer, Luciano; Meneghetti, Maria Cecília Zorél; Lima, Marcelo Andrade; Tersariol, Ivarne Luis Dos Santos; de Oliveira, Regina Costa; Nunes, Luiz R

    2017-02-07

    Xylella fastidiosa is a plant-infecting bacillus, responsible for many important crop diseases, such as Pierce's disease of vineyards, citrus variegated chlorosis, and coffee leaf scorch (CLS), among others. Recent genomic comparisons involving two CLS-related strains, belonging to X. fastidiosa subsp. pauca, revealed that one of them carries a frameshift mutation that inactivates a gene encoding an oxidoreductase of the short-chain dehydrogenase/reductase (SDR) superfamily, which may play important roles in determining structural variations in bacterial glycans and glycoconjugates. However, the exact nature of this SDR has been a matter of controversy, as different annotations of X. fastidiosa genomes have implicated it in distinct reactions. To confirm the nature of this mutated SDR, a comparative analysis was initially performed, suggesting that it belongs to a subgroup of SDR decarboxylases, representing a UDP-xylose synthase (Uxs). Functional assays, using a recombinant derivative of this enzyme, confirmed its nature as XfUxs, and carbohydrate composition analyses, performed with lipopolysaccharide (LPS) molecules obtained from different strains, indicate that inactivation of the X. fastidiosa uxs gene affects the LPS structure among CLS-related X. fastidiosa strains. Finally, a comparative sequence analysis suggests that this mutation is likely to result in a morphological and evolutionary hallmark that differentiates two subgroups of CLS-related strains, which may influence interactions between these bacteria and their plant and/or insect hosts.

  1. Genetic variability of aryl hydrocarbon receptor (AhR)-mediated regulation of the human UDP glucuronosyltransferase (UGT) 1A4 gene

    Energy Technology Data Exchange (ETDEWEB)

    Erichsen, Thomas J; Ehmer, Ursula; Kalthoff, Sandra; Lankisch, Tim O; Mueller, Tordis M [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany); Munzel, Peter A [Department of Toxicology, Institute of Pharmacology and Toxicology, University of Tubingen, Tubingen (Germany); Manns, Michael P [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany); Strassburg, Christian P. [Department of Gastroenterology, Hepatology and Endocrinology, Hannover, Medical School, Hannover (Germany)], E-mail: strassburg.christian@mh-hannover.de

    2008-07-15

    UDP glucuronosyltransferases (UGTs) play an important role for drug detoxification and toxicity. UGT function is genetically modulated by single nucleotide polymorphisms (SNPs) which lead to the expression of functionally altered protein, or altered expression levels. UGT1A4 activity includes anticonvulsants, antidepressants and environmental mutagens. In this study the induction of the human UGT1A4 gene and a potential influence of genetic variation in its promoter region were analyzed. SNPs at bp - 219 and - 163 occurred in 9% among 109 blood donors reducing UGT1A4 transcription by 40%. UGT1A4 transcription was dioxin inducible. Reporter gene experiments identified 2 xenobiotic response elements (XRE), which were functionally confirmed by mutagenesis analyses, and binding was demonstrated by electromobility shift assays. Constitutive human UGT1A4 gene expression and induction was aryl hydrocarbon receptor (AhR)-dependent, and reduced in the presence of SNPs at bp - 219 and - 163. AhR-mediated regulation of the human UGT1A4 gene by two XRE and a modulation by naturally occurring genetic variability by SNPs is demonstrated, which indicates gene-environment interaction with potential relevance for drug metabolism.

  2. Genetic variability of aryl hydrocarbon receptor (AhR)-mediated regulation of the human UDP glucuronosyltransferase (UGT) 1A4 gene

    International Nuclear Information System (INIS)

    Erichsen, Thomas J.; Ehmer, Ursula; Kalthoff, Sandra; Lankisch, Tim O.; Mueller, Tordis M.; Munzel, Peter A.; Manns, Michael P.; Strassburg, Christian P.

    2008-01-01

    UDP glucuronosyltransferases (UGTs) play an important role for drug detoxification and toxicity. UGT function is genetically modulated by single nucleotide polymorphisms (SNPs) which lead to the expression of functionally altered protein, or altered expression levels. UGT1A4 activity includes anticonvulsants, antidepressants and environmental mutagens. In this study the induction of the human UGT1A4 gene and a potential influence of genetic variation in its promoter region were analyzed. SNPs at bp - 219 and - 163 occurred in 9% among 109 blood donors reducing UGT1A4 transcription by 40%. UGT1A4 transcription was dioxin inducible. Reporter gene experiments identified 2 xenobiotic response elements (XRE), which were functionally confirmed by mutagenesis analyses, and binding was demonstrated by electromobility shift assays. Constitutive human UGT1A4 gene expression and induction was aryl hydrocarbon receptor (AhR)-dependent, and reduced in the presence of SNPs at bp - 219 and - 163. AhR-mediated regulation of the human UGT1A4 gene by two XRE and a modulation by naturally occurring genetic variability by SNPs is demonstrated, which indicates gene-environment interaction with potential relevance for drug metabolism

  3. Cloning, expression and characterization of a mammalian Nudix hydrolase-like enzyme that cleaves the pyrophosphate bond of UDP-glucose.

    Science.gov (United States)

    Yagi, Toshihiro; Baroja-Fernández, Edurne; Yamamoto, Ryuji; Muñoz, Francisco José; Akazawa, Takashi; Hong, Kyoung Su; Pozueta-Romero, Javier

    2003-03-01

    A distinct UDP-glucose (UDPG) pyrophosphatase (UGPPase, EC 3.6.1.45) has been characterized using pig kidney ( Sus scrofa ). This enzyme hydrolyses UDPG, the precursor molecule of numerous glycosylation reactions in animals, to produce glucose 1-phosphate (G1P) and UMP. Sequence analyses of the purified enzyme revealed that, similar to the case of a nucleotide-sugar hydrolase controlling the intracellular levels of ADP-glucose linked to glycogen biosynthesis in Escherichia coli [Moreno-Bruna, Baroja-Fernández, Muñoz, Bastarrica-Berasategui, Zandueta-Criado, Rodri;guez-López, Lasa, Akazawa and Pozueta-Romero (2001) Proc. Natl. Acad. Sci. U.S.A. 98, 8128-8132], UGPPase appears to be a member of the ubiquitously distributed group of nucleotide pyrophosphatases designated Nudix hydrolases. A complete cDNA of the UGPPase-encoding gene, designated UGPP, was isolated from a human thyroid cDNA library and expressed in E. coli. The resulting cells accumulated a protein that showed kinetic properties identical to those of pig UGPPase.

  4. Over-expression of UDP-glycosyltransferase gene UGT2B17 is involved in chlorantraniliprole resistance in Plutella xylostella (L.).

    Science.gov (United States)

    Li, Xiuxia; Zhu, Bin; Gao, Xiwu; Liang, Pei

    2017-07-01

    UDP-glycosyltransferases (UGTs) are phase II detoxification enzymes widely distributed within living organisms. Their involvement in the biotransformation of various lipophilic endogenous compounds and phytoalexins in insects has been documented. However, the roles of this enzyme family in insecticide resistance have rarely been reported. Here, the functions of UGTs in chlorantraniliprole resistance in Plutella xylostella were investigated. Treatment with sulfinpyrazone and 5-nitrouracil (both inhibitors of UGT enzymes) significantly increased the toxicity of chlorantraniliprole against the third instar larvae of P. xylostella. Among the 23 UGT transcripts examined, only UGT2B17 was found to be over-expressed (with a range from 30.7- to 77.3-fold) in all four chlorantraniliprole-resistant populations compared to the susceptible one (CHS). The knock-down of UGT2B17 by RNA interference (RNAi) dramatically increased the toxicity of chlorantraniliprole by 27.4% and 29.8% in the CHS and CHR (resistant) populations, respectively. In contrast, exposure to phenobarbital significantly increased the relative expression of UGT2B17 while decreasing the toxicity of chlorantraniliprole to the larvae by 14.0%. UGT2B17 is involved in the detoxification of chlorantraniliprole, and its over-expression may play an important role in chlorantraniliprole resistance in P. xylostella. These results shed some light upon and further our understanding of the mechanisms of diamide insecticide resistance in insects. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  5. Activity-Based Profiling of a Physiologic Aglycone Library Reveals Sugar Acceptor Promiscuity of Family 1 UDP-Glucosyltransferases from Grape1[W

    Science.gov (United States)

    Bönisch, Friedericke; Frotscher, Johanna; Stanitzek, Sarah; Rühl, Ernst; Wüst, Matthias; Bitz, Oliver; Schwab, Wilfried

    2014-01-01

    Monoterpenols serve various biological functions and accumulate in grape (Vitis vinifera), where a major fraction occurs as nonvolatile glycosides. We have screened the grape genome for sequences with similarity to terpene URIDINE DIPHOSPHATE GLYCOSYLTRANSFERASES (UGTs) from Arabidopsis (Arabidopsis thaliana). A ripening-related expression pattern was shown for three candidates by spatial and temporal expression analyses in five grape cultivars. Transcript accumulation correlated with the production of monoterpenyl β-d-glucosides in grape exocarp during ripening and was low in vegetative tissue. Targeted functional screening of the recombinant UGTs for their biological substrates was performed by activity-based metabolite profiling (ABMP) employing a physiologic library of aglycones built from glycosides isolated from grape. This approach led to the identification of two UDP-glucose:monoterpenol β-d-glucosyltransferases. Whereas VvGT14a glucosylated geraniol, R,S-citronellol, and nerol with similar efficiency, the three allelic forms VvGT15a, VvGT15b, and VvGT15c preferred geraniol over nerol. Kinetic resolution of R,S-citronellol and R,S-linalool was shown for VvGT15a and VvGT14a, respectively. ABMP revealed geraniol as the major biological substrate but also disclosed that these UGTs may add to the production of further glycoconjugates in planta. ABMP of aglycone libraries provides a versatile tool to uncover novel biologically relevant substrates of small-molecule glycosyltransferases that often show broad sugar acceptor promiscuity. PMID:25073706

  6. Single Nucleotide Polymorphisms in B-Genome Specific UDP-Glucosyl Transferases Associated with Fusarium Head Blight Resistance and Reduced Deoxynivalenol Accumulation in Wheat Grain.

    Science.gov (United States)

    Sharma, Pallavi; Gangola, Manu P; Huang, Chen; Kutcher, H Randy; Ganeshan, Seedhabadee; Chibbar, Ravindra N

    2018-01-01

    An in vitro spike culture method was optimized to evaluate Fusarium head blight (FHB) resistance in wheat (Triticum aestivum) and used to screen a population of ethyl methane sulfonate treated spike culture-derived variants (SCDV). Of the 134 SCDV evaluated, the disease severity score of 47 of the variants was ≤30%. Single nucleotide polymorphisms (SNP) in the UDP-glucosyltransferase (UGT) genes, TaUGT-2B, TaUGT-3B, and TaUGT-EST, differed between AC Nanda (an FHB-susceptible wheat variety) and Sumai-3 (an FHB-resistant wheat cultivar). SNP at 450 and 1,558 bp from the translation initiation site in TaUGT-2B and TaUGT-3B, respectively were negatively correlated with FHB severity in the SCDV population, whereas the SNP in TaUGT-EST was not associated with FHB severity. Fusarium graminearum strain M7-07-1 induced early expression of TaUGT-2B and TaUGT-3B in FHB-resistant SCDV lines, which were associated with deoxynivalenol accumulation and reduced FHB disease progression. At 8 days after inoculation, deoxynivalenol concentration varied from 767 ppm in FHB-resistant variants to 2,576 ppm in FHB-susceptible variants. The FHB-resistant SCDV identified can be used as new sources of FHB resistance in wheat improvement programs.

  7. Quantitative Characterization of Major Hepatic UDP-Glucuronosyltransferase Enzymes in Human Liver Microsomes: Comparison of Two Proteomic Methods and Correlation with Catalytic Activity.

    Science.gov (United States)

    Achour, Brahim; Dantonio, Alyssa; Niosi, Mark; Novak, Jonathan J; Fallon, John K; Barber, Jill; Smith, Philip C; Rostami-Hodjegan, Amin; Goosen, Theunis C

    2017-10-01

    Quantitative characterization of UDP-glucuronosyltransferase (UGT) enzymes is valuable in glucuronidation reaction phenotyping, predicting metabolic clearance and drug-drug interactions using extrapolation exercises based on pharmacokinetic modeling. Different quantitative proteomic workflows have been employed to quantify UGT enzymes in various systems, with reports indicating large variability in expression, which cannot be explained by interindividual variability alone. To evaluate the effect of methodological differences on end-point UGT abundance quantification, eight UGT enzymes were quantified in 24 matched liver microsomal samples by two laboratories using stable isotope-labeled (SIL) peptides or quantitative concatemer (QconCAT) standard, and measurements were assessed against catalytic activity in seven enzymes ( n = 59). There was little agreement between individual abundance levels reported by the two methods; only UGT1A1 showed strong correlation [Spearman rank order correlation (Rs) = 0.73, P quantitative proteomic data should be validated against catalytic activity whenever possible. In addition, metabolic reaction phenotyping exercises should consider spurious abundance-activity correlations to avoid misleading conclusions. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

  8. A genome-wide phylogenetic reconstruction of family 1 UDP-glycosyltransferases revealed the expansion of the family during the adaptation of plants to life on land.

    Science.gov (United States)

    Caputi, Lorenzo; Malnoy, Mickael; Goremykin, Vadim; Nikiforova, Svetlana; Martens, Stefan

    2012-03-01

    For almost a decade, our knowledge on the organisation of the family 1 UDP-glycosyltransferases (UGTs) has been limited to the model plant A. thaliana. The availability of other plant genomes represents an opportunity to obtain a broader view of the family in terms of evolution and organisation. Family 1 UGTs are known to glycosylate several classes of plant secondary metabolites. A phylogeny reconstruction study was performed to get an insight into the evolution of this multigene family during the adaptation of plants to life on land. The organisation of the UGTs in the different organisms was also investigated. More than 1500 putative UGTs were identified in 12 fully sequenced and assembled plant genomes based on the highly conserved PSPG motif. Analyses by maximum likelihood (ML) method were performed to reconstruct the phylogenetic relationships existing between the sequences. The results of this study clearly show that the UGT family expanded during the transition from algae to vascular plants and that in higher plants the clustering of UGTs into phylogenetic groups appears to be conserved, although gene loss and gene gain events seem to have occurred in certain lineages. Interestingly, two new phylogenetic groups, named O and P, that are not present in A. thaliana were discovered. © 2011 The Authors. The Plant Journal © 2011 Blackwell Publishing Ltd.

  9. Analysis of the Staphylococcus aureus capsule biosynthesis pathway in vitro: characterization of the UDP-GlcNAc C6 dehydratases CapD and CapE and identification of enzyme inhibitors.

    Science.gov (United States)

    Li, Wenjin; Ulm, Hannah; Rausch, Marvin; Li, Xue; O'Riordan, Katie; Lee, Jean C; Schneider, Tanja; Müller, Christa E

    2014-11-01

    Polysaccharide capsules significantly contribute to virulence of invasive pathogens, and inhibition of capsule biosynthesis may offer a valuable strategy for novel anti-infective treatment. We purified and characterized the enzymes CapD and CapE of the Staphylococcus aureus serotype 5 biosynthesis cluster, which catalyze the first steps in the synthesis of the soluble capsule precursors UDP-D-FucNAc and UDP-L-FucNAc, respectively. CapD is an integral membrane protein and was obtained for the first time in a purified, active form. A capillary electrophoresis (CE)-based method applying micellar electrokinetic chromatography (MEKC) coupled with UV detection at 260 nm was developed for functional characterization of the enzymes using a fused-silica capillary, electrokinetic injection, and dynamic coating with polybrene at pH 12.4. The limits of detection for the CapD and CapE products UDP-2-acetamido-2,6-dideoxy-α-D-xylo-hex-4-ulose and UDP-2-acetamido-2,6-dideoxy-β-L-arabino-hex-4-ulose, respectively, were below 1 μM. Using this new, robust and sensitive method we performed kinetic studies for CapD and CapE and screened a compound library in search for enzyme inhibitors. Several active compounds were identified and characterized, including suramin (IC50 at CapE 1.82 μM) and ampicillin (IC50 at CapD 40.1 μM). Furthermore, the cell wall precursors UDP-D-MurNAc-pentapeptide and lipid II appear to function as inhibitors of CapD enzymatic activity, suggesting an integrated mechanism of regulation for cell envelope biosynthesis pathways in S. aureus. Corroborating the in vitro findings, staphylococcal cells grown in the presence of subinhibitory concentrations of ampicillin displayed drastically reduced CP production. Our studies contribute to a profound understanding of the capsule biosynthesis in pathogenic bacteria. This approach may lead to the identification of novel anti-virulence and antibiotic drugs. Copyright © 2014 Elsevier GmbH. All rights reserved.

  10. Vanillin formation from ferulic acid in Vanilla planifolia is catalysed by a single enzyme

    DEFF Research Database (Denmark)

    Gallage, Nethaji J; Hansen, Esben H; Kannangara, Rubini

    2014-01-01

    Vanillin is a popular and valuable flavour compound. It is the key constituent of the natural vanilla flavour obtained from cured vanilla pods. Here we show that a single hydratase/lyase type enzyme designated vanillin synthase (VpVAN) catalyses direct conversion of ferulic acid and its glucoside...... to the inner part of the vanilla pod and high transcript levels are found in single cells located a few cell layers from the inner epidermis. Transient expression of VpVAN in tobacco and stable expression in barley in combination with the action of endogenous alcohol dehydrogenases and UDP...

  11. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation.

    Science.gov (United States)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian; Wagtberg Sen, Jette; Rasmussen, Søren Kofoed; Kontoravdi, Cleo; Weilguny, Dietmar; Andersen, Mikael Rørdam

    2015-03-01

    Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylation-related product quality. In this work, different fed-batch processes with two chemically defined proprietary media and feeds were studied using two IgG-producing cell lines. Our results indicate that the balance of glucose and amino acid concentration in the culture is important for cell growth, IgG titer and N-glycosylation. Accordingly, the ideal fate of glucose and amino acids in the culture could be mainly towards energy and recombinant product, respectively. Accumulation of by-products such as NH4(+) and lactate as a consequence of unbalanced nutrient supply to cell activities inhibits cell growth. The levels of Leu and Arg in the culture, which relate to cell growth and IgG productivity, need to be well controlled. Amino acids with the highest consumption rates correlate with the most abundant amino acids present in the produced IgG, and thus require sufficient availability during culture. Case-by-case analysis is necessary for understanding the effect of media and process optimization on glycosylation. We found that in certain cases the presence of Man5 glycan can be linked to limitation of UDP-GlcNAc biosynthesis as a result of insufficient extracellular Gln. However, under different culture conditions, high Man5 levels can also result from low α-1,3-mannosyl-glycoprotein 2-β-N-acetylglucosaminyltransferase (GnTI) and UDP-GlcNAc transporter activities, which may be attributed to high level of NH4+ in the cell culture. Furthermore, galactosylation of the mAb Fc glycans

  12. Molecular cloning and biochemical characterization of the UDP-glucose: flavonoid 3-O-glucosyltransferase from Concord grape (Vitis labrusca).

    Science.gov (United States)

    Hall, Dawn; Yuan, Xiao Xin; Murata, Jun; De Luca, Vincenzo

    2012-02-01

    Glucosylation of anthocyanidin substrates at the 3-O-position is crucial for the red pigmentation of grape berries and wine. The gene that encodes the enzyme involved in this reaction has been cloned from Vitis labrusca cv. Concord, heterologously expressed, and the recombinant enzyme (rVL3GT) was characterized. VL3GT has 96% amino acid sequence identity with Vitis vinifera VV3GT and groups phylogenetically with several other flavonoid 3-O-glycosyltransferases. In vitro substrate specificity studies and kinetic analyses of rVL3GT indicate that this enzyme preferentially glucosylates cyanidin as compared with quercetin. Crude protein extracts from several Concord grape tissues were assayed for glucosyltransferase activity with cyanidin and quercetin as acceptor substrates. A comparison of the VL3GT activities toward with these substrates showed that the 3GT enzyme activity is consistent with the expression of VL3GT in these tissues and is coincident with the biosynthesis of anthocyanins in both location and developmental stages. Enzyme activities in grape mesocarp, pre-veraison exocarp, leaf, flower bud, and flower tissues glucosylated quercetin but not cyanidin at high rates, suggesting the presence of additional enzymes which are able to glucosylate the 3-O-position of flavonols with higher specificity than anthocyanidins. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Coupling of UDP-glucuronosyltransferases and multidrug resistance-associated proteins is responsible for the intestinal disposition and poor bioavailability of emodin

    International Nuclear Information System (INIS)

    Liu, Wei; Feng, Qian; Li, Ye; Ye, Ling; Hu, Ming; Liu, Zhongqiu

    2012-01-01

    Emodin is a poorly bioavailable but promising plant-derived anticancer drug candidate. The low oral bioavailability of emodin is due to its extensive glucuronidation in the intestine and liver. Caco-2 cell culture model was used to investigate the interplay between UDP-glucuronosyltransferases (UGTs) and efflux transporters in the intestinal disposition of emodin. Bidirectional transport assays of emodin at different concentrations were performed in the Caco-2 monolayers with or without multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP) efflux transporter chemical inhibitors. The bidirectional permeability of emodin and its glucuronide in the Caco-2 monolayers was determined. Emodin was rapidly metabolized to emodin glucuronide in Caco-2 cells. LTC4, a potent inhibitor of MRP2, decreased the efflux of emodin glucuronide and also substantially increased the intracellular glucuronide level in the basolateral-to-apical (B–A) direction. MK-571, chemical inhibitor of MRP2, MRP3, and MRP4, significantly reduced the efflux of glucuronide in the apical-to-basolateral (A–B) and B–A directions in a dose-dependent manner. However, dipyridamole, a BCRP chemical inhibitor demonstrated no effect on formation and efflux of emodin glucuronide in Caco-2 cells. In conclusion, UGT is a main metabolic pathway for emodin in the intestine, and the MRP family is composed of major efflux transporters responsible for the excretion of emodin glucuronide in the intestine. The coupling of UGTs and MRP efflux transporters causes the extensive metabolism, excretion, and low bioavailability of emodin. -- Highlights: ► Glucuronidation is the main reason for the poor oral bioavailability of emodin. ► Efflux transporters are involved in the excretion of emodin glucuronide. ► The intestine is the main organ for metabolism of emodin.

  14. Herb–drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hai-Ying [The Fourth Affiliated Hospital of China Medical University, Shenyang 110032 (China); Sun, Dong-Xue [School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang 110016 (China); Cao, Yun-Feng [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Ai, Chun-Zhi [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Qu, Yan-Qing [Thyroid Surgery, Yantaishan Hospital, Yantai, Shandong (China); Hu, Cui-Min [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057 (United States); Jiang, Changtao [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Dong, Pei-Pei [Academy of Integrative Medicine, Dalian Medical University, Dalian 116044 (China); Sun, Xiao-Yu; Hong, Mo [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Tanaka, Naoki; Gonzalez, Frank J. [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); others, and

    2014-05-15

    Herb–drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (K{sub i}) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (K{sub i}) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb–drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7. - Highlights: • Specific inhibition of andrographolide derivatives towards UGT2B7. • Herb-drug interaction related withAndrographis paniculata. • Guidance for design of UGT2B7 specific inhibitors.

  15. Herb–drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7

    International Nuclear Information System (INIS)

    Ma, Hai-Ying; Sun, Dong-Xue; Cao, Yun-Feng; Ai, Chun-Zhi; Qu, Yan-Qing; Hu, Cui-Min; Jiang, Changtao; Dong, Pei-Pei; Sun, Xiao-Yu; Hong, Mo; Tanaka, Naoki; Gonzalez, Frank J.

    2014-01-01

    Herb–drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (K i ) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (K i ) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb–drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7. - Highlights: • Specific inhibition of andrographolide derivatives towards UGT2B7. • Herb-drug interaction related withAndrographis paniculata. • Guidance for design of UGT2B7 specific inhibitors

  16. Relation of Transcriptional Factors to the Expression and Activity of Cytochrome P450 and UDP-Glucuronosyltransferases 1A in Human Liver: Co-Expression Network Analysis.

    Science.gov (United States)

    Zhong, Shilong; Han, Weichao; Hou, Chuqi; Liu, Junjin; Wu, Lili; Liu, Menghua; Liang, Zhi; Lin, Haoming; Zhou, Lili; Liu, Shuwen; Tang, Lan

    2017-01-01

    Cytochrome P450 (CYPs) and UDP-glucuronosyltransferases (UGTs) play important roles in the metabolism of exogenous and endogenous compounds. The gene transcription of CYPs and UGTs can be enhanced or reduced by transcription factors (TFs). This study aims to explore novel TFs involved in the regulatory network of human hepatic UGTs/CYPs. Correlations between the transcription levels of 683 key TFs and CYPs/UGTs in three different human liver expression profiles (n = 640) were calculated first. Supervised weighted correlation network analysis (sWGCNA) was employed to define hub genes among the selected TFs. The relationship among 17 defined TFs, CYPs/UGTs expression, and activity were evaluated in 30 liver samples from Chinese patients. The positive controls (e.g., PPARA, NR1I2, NR1I3) and hub TFs (NFIA, NR3C2, and AR) in the Grey sWGCNA Module were significantly and positively associated with CYPs/UGTs expression. And the cancer- or inflammation-related TFs (TEAD4, NFKB2, and NFKB1) were negatively associated with mRNA expression of CYP2C9/CYP2E1/UGT1A9. Furthermore, the effect of NR1I2, NR1I3, AR, TEAD4, and NFKB2 on CYP450/UGT1A gene transcription translated into moderate influences on enzyme activities. To our knowledge, this is the first study to integrate Gene Expression Omnibus (GEO) datasets and supervised weighted correlation network analysis (sWGCNA) for defining TFs potentially related to CYPs/UGTs. We detected several novel TFs involved in the regulatory network of hepatic CYPs and UGTs in humans. Further validation and investigation may reveal their exact mechanism of CYPs/UGTs regulation.

  17. Inhibitory Role of Greatwall-Like Protein Kinase Rim15p in Alcoholic Fermentation via Upregulating the UDP-Glucose Synthesis Pathway in Saccharomyces cerevisiae.

    Science.gov (United States)

    Watanabe, Daisuke; Zhou, Yan; Hirata, Aiko; Sugimoto, Yukiko; Takagi, Kenichi; Akao, Takeshi; Ohya, Yoshikazu; Takagi, Hiroshi; Shimoi, Hitoshi

    2016-01-01

    The high fermentation rate of Saccharomyces cerevisiae sake yeast strains is attributable to a loss-of-function mutation in the RIM15 gene, which encodes a Greatwall-family protein kinase that is conserved among eukaryotes. In the present study, we performed intracellular metabolic profiling analysis and revealed that deletion of the RIM15 gene in a laboratory strain impaired glucose-anabolic pathways through the synthesis of UDP-glucose (UDPG). Although Rim15p is required for the synthesis of trehalose and glycogen from UDPG upon entry of cells into the quiescent state, we found that Rim15p is also essential for the accumulation of cell wall β-glucans, which are also anabolic products of UDPG. Furthermore, the impairment of UDPG or 1,3-β-glucan synthesis contributed to an increase in the fermentation rate. Transcriptional induction of PGM2 (phosphoglucomutase) and UGP1 (UDPG pyrophosphorylase) was impaired in Rim15p-deficient cells in the early stage of fermentation. These findings demonstrate that the decreased anabolism of glucose into UDPG and 1,3-β-glucan triggered by a defect in the Rim15p-mediated upregulation of PGM2 and UGP1 redirects the glucose flux into glycolysis. Consistent with this, sake yeast strains with defective Rim15p exhibited impaired expression of PGM2 and UGP1 and decreased levels of β-glucans, trehalose, and glycogen during sake fermentation. We also identified a sake yeast-specific mutation in the glycogen synthesis-associated glycogenin gene GLG2, supporting the conclusion that the glucose-anabolic pathway is impaired in sake yeast. These findings demonstrate that downregulation of the UDPG synthesis pathway is a key mechanism accelerating alcoholic fermentation in industrially utilized S. cerevisiae sake strains. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  18. 3,5-Dioxopyrazolidines, Novel Inhibitors of UDP-N- Acetylenolpyruvylglucosamine Reductase (MurB) with Activity against Gram-Positive Bacteria

    Science.gov (United States)

    Yang, Youjun; Severin, Anatoly; Chopra, Rajiv; Krishnamurthy, Girija; Singh, Guy; Hu, William; Keeney, David; Svenson, Kristine; Petersen, Peter J.; Labthavikul, Pornpen; Shlaes, David M.; Rasmussen, Beth A.; Failli, Amedeo A.; Shumsky, Jay S.; Kutterer, Kristina M. K.; Gilbert, Adam; Mansour, Tarek S.

    2006-01-01

    A series of 3,5-dioxopyrazolidines was identified as novel inhibitors of UDP-N-acetylenolpyruvylglucosamine reductase (MurB). Compounds 1 to 3, which are 1,2-bis(4-chlorophenyl)-3,5-dioxopyrazolidine-4-carboxamides, inhibited Escherichia coli MurB, Staphyloccocus aureus MurB, and E. coli MurA with 50% inhibitory concentrations (IC50s) in the range of 4.1 to 6.8 μM, 4.3 to 10.3 μM, and 6.8 to 29.4 μM, respectively. Compound 4, a C-4-unsubstituted 1,2-bis(3,4-dichlorophenyl)-3,5-dioxopyrazolidine, showed moderate inhibitory activity against E. coli MurB, S. aureus MurB, and E. coli MurC (IC50s, 24.5 to 35 μM). A fluorescence-binding assay indicated tight binding of compound 3 with E. coli MurB, giving a dissociation constant of 260 nM. Structural characterization of E. coli MurB was undertaken, and the crystal structure of a complex with compound 4 was obtained at 2.4 Å resolution. The crystal structure indicated the binding of a compound at the active site of MurB and specific interactions with active-site residues and the bound flavin adenine dinucleotide cofactor. Peptidoglycan biosynthesis studies using a strain of Staphylococcus epidermidis revealed reduced peptidoglycan biosynthesis upon incubation with 3,5-dioxopyrazolidines, with IC50s of 0.39 to 11.1 μM. Antibacterial activity was observed for compounds 1 to 3 (MICs, 0.25 to 16 μg/ml) and 4 (MICs, 4 to 8 μg/ml) against gram-positive bacteria including methicillin-resistant S. aureus, vancomycin-resistant Enterococcus faecalis, and penicillin-resistant Streptococcus pneumoniae. PMID:16436710

  19. Herb–drug interaction prediction based on the high specific inhibition of andrographolide derivatives towards UDP-glucuronosyltransferase (UGT) 2B7

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Hai-Ying, E-mail: cmu4h-mhy@126.com [The Fourth Affiliated Hospital of China Medical University, Shenyang 110032 (China); Sun, Dong-Xue [School of Traditional Chinese Medicine, Shenyang Pharmaceutical University, No. 103, Wenhua Road, Shenyang 110016 (China); Cao, Yun-Feng [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Ai, Chun-Zhi [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Qu, Yan-Qing [Thyroid Surgery, Yantaishan Hospital, Yantai, Shandong (China); Hu, Cui-Min [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Department of Microbiology and Immunology, Georgetown University Medical Center, Washington, DC 20057 (United States); Jiang, Changtao [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Dong, Pei-Pei [Academy of Integrative Medicine, Dalian Medical University, Dalian 116044 (China); Sun, Xiao-Yu; Hong, Mo [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road, Dalian 116023 (China); Tanaka, Naoki; Gonzalez, Frank J. [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); and others

    2014-05-15

    Herb–drug interaction strongly limits the clinical application of herbs and drugs, and the inhibition of herbal components towards important drug-metabolizing enzymes (DMEs) has been regarded as one of the most important reasons. The present study aims to investigate the inhibition potential of andrographolide derivatives towards one of the most important phase II DMEs UDP-glucuronosyltransferases (UGTs). Recombinant UGT isoforms (except UGT1A4)-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction and UGT1A4-catalyzed trifluoperazine (TFP) glucuronidation were employed to firstly screen the andrographolide derivatives' inhibition potential. High specific inhibition of andrographolide derivatives towards UGT2B7 was observed. The inhibition type and parameters (K{sub i}) were determined for the compounds exhibiting strong inhibition capability towards UGT2B7, and human liver microsome (HLMs)-catalyzed zidovudine (AZT) glucuronidation probe reaction was used to furtherly confirm the inhibition behavior. In combination of inhibition parameters (K{sub i}) and in vivo concentration of andrographolide and dehydroandrographolide, the potential in vivo inhibition magnitude was predicted. Additionally, both the in vitro inhibition data and computational modeling results provide important information for the modification of andrographolide derivatives as selective inhibitors of UGT2B7. Taken together, data obtained from the present study indicated the potential herb–drug interaction between Andrographis paniculata and the drugs mainly undergoing UGT2B7-catalyzed metabolic elimination, and the andrographolide derivatives as potential candidates for the selective inhibitors of UGT2B7. - Highlights: • Specific inhibition of andrographolide derivatives towards UGT2B7. • Herb-drug interaction related withAndrographis paniculata. • Guidance for design of UGT2B7 specific inhibitors.

  20. Coupling of UDP-glucuronosyltransferases and multidrug resistance-associated proteins is responsible for the intestinal disposition and poor bioavailability of emodin

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Feng, Qian; Li, Ye; Ye, Ling [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China); Hu, Ming, E-mail: mhu@uh.edu [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China); Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 1441 Moursund Street, Houston, TX 77030 (United States); Liu, Zhongqiu, E-mail: liuzq@smu.edu.cn [Department of Pharmaceutics, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, Guangdong (China)

    2012-12-15

    Emodin is a poorly bioavailable but promising plant-derived anticancer drug candidate. The low oral bioavailability of emodin is due to its extensive glucuronidation in the intestine and liver. Caco-2 cell culture model was used to investigate the interplay between UDP-glucuronosyltransferases (UGTs) and efflux transporters in the intestinal disposition of emodin. Bidirectional transport assays of emodin at different concentrations were performed in the Caco-2 monolayers with or without multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP) efflux transporter chemical inhibitors. The bidirectional permeability of emodin and its glucuronide in the Caco-2 monolayers was determined. Emodin was rapidly metabolized to emodin glucuronide in Caco-2 cells. LTC4, a potent inhibitor of MRP2, decreased the efflux of emodin glucuronide and also substantially increased the intracellular glucuronide level in the basolateral-to-apical (B–A) direction. MK-571, chemical inhibitor of MRP2, MRP3, and MRP4, significantly reduced the efflux of glucuronide in the apical-to-basolateral (A–B) and B–A directions in a dose-dependent manner. However, dipyridamole, a BCRP chemical inhibitor demonstrated no effect on formation and efflux of emodin glucuronide in Caco-2 cells. In conclusion, UGT is a main metabolic pathway for emodin in the intestine, and the MRP family is composed of major efflux transporters responsible for the excretion of emodin glucuronide in the intestine. The coupling of UGTs and MRP efflux transporters causes the extensive metabolism, excretion, and low bioavailability of emodin. -- Highlights: ► Glucuronidation is the main reason for the poor oral bioavailability of emodin. ► Efflux transporters are involved in the excretion of emodin glucuronide. ► The intestine is the main organ for metabolism of emodin.

  1. Dermatan Sulfate Epimerase 1-Deficient Mice Have Reduced Content and Changed Distribution of Iduronic Acids in Dermatan Sulfate and an Altered Collagen Structure in Skin

    DEFF Research Database (Denmark)

    Maccarana, M.; Kalamajski, S.; Kongsgaard, M.

    2009-01-01

    Dermatan sulfate epimerase 1 (DS-epi1) and DS-epi2 convert glucuronic acid to iduronic acid in chondroitin/dermatan sulfate biosynthesis. Here we report on the generation of DS-epi1-null mice and the resulting alterations in the chondroitin/dermatan polysaccharide chains. The numbers of long blocks......-derived chains. DS-epi1-deficient mice are smaller than their wild-type littermates but otherwise have no gross macroscopic alterations. The lack of DS-epi1 affects the chondroitin/dermatan sulfate in many proteoglycans, and the consequences for skin collagen structure were initially analyzed. We found...... that the skin collagen architecture was altered, and electron microscopy showed that the DS-epi1-null fibrils have a larger diameter than the wild-type fibrils. The altered chondroitin/dermatan sulfate chains carried by decorin in skin are likely to affect collagen fibril formation and reduce the tensile...

  2. Structures of the K35 and K15 capsular polysaccharides of Acinetobacter baumannii LUH5535 and LUH5554 containing amino and diamino uronic acids.

    Science.gov (United States)

    Shashkov, Alexander S; Liu, Bin; Kenyon, Johanna J; Popova, Anastasiya V; Shneider, Mikhail M; Senchenkova, Sof'ya N; Arbatsky, Nikolay P; Miroshnikov, Konstantin A; Wang, Lei; Knirel, Yuriy A

    2017-08-07

    Capsular polysaccharides were isolated from A. baumannii LUH5535 (K35 CPS) and LUH5554 (K15 CPS) and studied by 1D and 2D 1 H and 13 C NMR spectroscopy. The CPSs were found to consist of linear tetrasaccharide repeats (K units) containing 2-acetamido-2-deoxy-d-galacturonic acid (K35) or 2,3-diacetamido-2,3-deoxy-d-glucuronic acid (K15) and 2,4-diacetamido-2,4,6-trideoxy-d-glucose (both CPSs). The K35 unit includes three O-acetyl groups on different GalNAcA residues. A. baumannii LUH5535 and LUH5554 carry the KL35 and KL15 gene clusters, respectively, and putatively assigned functions of genes in these clusters were consistent with the CPS structures established. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Inhibition of UDP-glucosylceramide synthase in mice prevents Gaucher disease-associated B-cell malignancy.

    Science.gov (United States)

    Pavlova, Elena V; Archer, Joy; Wang, Susan; Dekker, Nick; Aerts, Johannes Mfg; Karlsson, Stefan; Cox, Timothy M

    2015-01-01

    Clonal B-cell proliferation is a frequent manifestation of Gaucher disease - a sphingolipidosis associated with a high risk of multiple myeloma and non-Hodgkin lymphoma. Gaucher disease is caused by genetic deficiency of acid β-glucosidase, the natural substrates of which (β-d-glucosylceramide and β-d-glucosylsphingosine) accumulate, principally in macrophages. Mice with inducible deficiency of β-glucosidase [Gba(tm1Karl/tm1Karl)Tg(MX1-cre)1Cgn/0] serve as an authentic model of human Gaucher disease; we have recently reported clonal B-cell proliferation accompanied by monoclonal serum paraproteins and cognate tumours in these animals. To explore the relationship between B-cell malignancy and the biochemical defect, we treated Gaucher mice with eliglustat tartrate (GENZ 112638), a potent and selective inhibitor of the first committed step in glycosphingolipid biosynthesis. Twenty-two Gaucher mice received 300 mg/kg of GENZ 112638 daily for 3-10 months from 6 weeks of age. Plasma concentrations of β-d-glucosylceramide and the unacylated glycosphingolipid, β-d-glucosylsphingosine, declined. After administration of GENZ 112638 to Gaucher mice for 3-10 months, serum paraproteins were not detected and there was a striking reduction in the malignant lymphoproliferation: neither lymphomas nor plasmacytomas were found in animals that had received the investigational agent. In contrast, 14 out of 60 Gaucher mice without GENZ 112638 treatment developed these tumours; monoclonal paraproteins were detected in plasma from 18 of the 44 age-matched mice with Gaucher disease that had not received GENZ 112638. Long-term inhibition of glycosphingolipid biosynthesis suppresses the development of spontaneous B-cell lymphoma and myeloma in Gaucher mice. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  4. Identification and functional characterization of a flax UDP-glycosyltransferase glucosylating secoisolariciresinol (SECO) into secoisolariciresinol monoglucoside (SMG) and diglucoside (SDG).

    Science.gov (United States)

    Ghose, Kaushik; Selvaraj, Kumarakurubaran; McCallum, Jason; Kirby, Chris W; Sweeney-Nixon, Marva; Cloutier, Sylvie J; Deyholos, Michael; Datla, Raju; Fofana, Bourlaye

    2014-03-28

    Lignans are a class of diphenolic nonsteroidal phytoestrogens often found glycosylated in planta. Flax seeds are a rich source of secoisolariciresinol diglucoside (SDG) lignans. Glycosylation is a process by which a glycosyl group is covalently attached to an aglycone substrate and is catalyzed by uridine diphosphate glycosyltransferases (UGTs). Until now, very little information was available on UGT genes that may play a role in flax SDG biosynthesis. Here we report on the identification, structural and functional characterization of 5 putative UGTs potentially involved in secoisolariciresinol (SECO) glucosylation in flax. Five UGT genes belonging to the glycosyltransferases' family 1 (EC 2.4.x.y) were cloned and characterized. They fall under four UGT families corresponding to five sub-families referred to as UGT74S1, UGT74T1, UGT89B3, UGT94H1, UGT712B1 that all display the characteristic plant secondary product glycosyltransferase (PSPG) conserved motif. However, diversity was observed within this 44 amino acid sequence, especially in the two peptide sequences WAPQV and HCGWNS known to play a key role in the recognition and binding of diverse aglycone substrates and in the sugar donor specificity. In developing flax seeds, UGT74S1 and UGT94H1 showed a coordinated gene expression with that of pinoresinol-lariciresinol reductase (PLR) and their gene expression patterns correlated with SDG biosynthesis. Enzyme assays of the five heterologously expressed UGTs identified UGT74S1 as the only one using SECO as substrate, forming SECO monoglucoside (SMG) and then SDG in a sequential manner. We have cloned and characterized five flax UGTs and provided evidence that UGT74S1 uses SECO as substrate to form SDG in vitro. This study allowed us to propose a model for the missing step in SDG lignan biosynthesis.

  5. Biochemical and Structural Characterization of WlbA from Bordetella pertussis and Chromobacterium violaceum: Enzymes Required for the Biosynthesis of 2,3-Diacetamido-2,3-dideoxy-d-mannuronic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Thoden, James B.; Holden, Hazel M. (UW)

    2011-12-22

    The unusual sugar 2,3-diacetamido-2,3-dideoxy-d-mannuronic acid, or ManNAc3NAcA, has been observed in the lipopolysaccharides of both pathogenic and nonpathogenic Gram-negative bacteria. It is added to the lipopolysaccharides of these organisms by glycosyltransferases that use as substrates UDP-ManNAc3NAcA. Five enzymes are ultimately required for the biosynthesis of UDP-ManNAc3NAcA starting from UDP-N-acetylglucosamine. The second enzyme in the pathway, encoded by the wlba gene and referred to as WlbA, catalyzes the NAD-dependent oxidation of the C-3' hydroxyl group of the UDP-linked sugar. Here we describe a combined structural and functional investigation of the WlbA enzymes from Bordetella pertussis and Chromobacterium violaceum. For this investigation, ternary structures were determined in the presence of NAD(H) and substrate to 2.13 and 1.5 {angstrom} resolution, respectively. Both of the enzymes display octameric quaternary structures with their active sites positioned far apart. The octamers can be envisioned as tetramers of dimers. Kinetic studies demonstrate that the reaction mechanisms for these enzymes are sequential and that they do not require {alpha}-ketoglutarate for activity. These results are in sharp contrast to those recently reported for the WlbA enzymes from Pseudomonas aeruginosa and Thermus thermophilus, which function via ping-pong mechanisms that involve {alpha}-ketoglutarate. Taken together, the results reported here demonstrate that there are two distinct families of WlbA enzymes, which differ with respect to amino acid sequences, quaternary structures, active site architectures, and kinetic mechanisms.

  6. Effects of organic solvents on hyaluronic acid nanoparticles obtained by precipitation and chemical crosslinking.

    Science.gov (United States)

    Bicudo, Rafaela Costa Souza; Santana, Maria Helena Andrade

    2012-03-01

    Hyaluronic acid is a hydrophilic mucopolysaccharide composed of alternating units of D-glucuronic acid and N-acetylglucosamine. It is used in many medical, pharmaceutical, and cosmetic applications, as sponges, films, or particle formulations. Hyaluronic acid nanoparticles can be synthesized free of oil and surfactants by nanoprecipitation in organic solvents, followed by chemical crosslinking. The organic solvent plays an important role in particles size and structure. Therefore, this study aimed to investigate the influence of acetone, ethanol, and isopropyl alcohol on the synthesis and physico-chemical properties of hyaluronic acid nanoparticles. Particles were crosslinked with adipic hydrazide and chloride carbodiimide under controlled conditions. The nanoparticles obtained with all three studied solvents were moderately electrostatically stable. Experiments with acetone produced the smallest particle size (120.44 nm) and polydispersity (0.27). The size and polydispersity of hyaluronic acid nanoparticles correlated with the surface tension between water and the organic solvents, not with the thermodynamic affinity of water for the organic solvents.

  7. Mangifera indica L. extract and mangiferin modulate cytochrome P450 and UDP-glucuronosyltransferase enzymes in primary cultures of human hepatocytes.

    Science.gov (United States)

    Rodeiro, Idania; José Gómez-Lechón, M; Perez, Gabriela; Hernandez, Ivones; Herrera, José Alfredo; Delgado, Rene; Castell, José V; Teresa Donato, M

    2013-05-01

    The aqueous stem bark extract of Mangifera indica L. (MSBE) has been reported to have antioxidant, anti-inflammatory and analgesic properties. In previous studies, we showed that MSBE and mangiferin, its main component, lower the activity of some cytochrome P-450 (P450) enzymes in rat hepatocytes and human liver microsomes. In the present study, the effects of MSBE and mangiferin on several P450 enzymes and UDP-glucuronosyltransferases (UGTs) in human-cultured hepatocytes have been examined. After hepatocytes underwent a 48-h treatment with sub-cytotoxic concentrations of the products (50-250 µg/mL), a concentration-dependent decrease of the activity of the five P450 enzymes measured (CYP1A2, 2A6, 2C9, 2D6 and 3A4) was observed. For all the activities, a reduction of at least 50% at the highest concentration (250 µg/mL) was observed. In addition, UGT activities diminished. MSBE considerably reduced UGT1A9 activity (about 60% at 250 µg/mL) and lesser effects on the other UGTs. In contrast, 250 µg/mL mangiferin had greater effects on UGT1A1 and 2B7 than on UGT1A9 (about 55% vs. 35% reduction, respectively). Quantification of specific mRNAs revealed reduced CYP3A4 and 3A5 mRNAs content, and an increase in CYP1A1, CYP1A2, UGT1A1 and UGT1A9 mRNAs. No remarkable effects on the CYP2A6, 2B6, 2C9, 2C19, 2D6 and 2E1 levels were observed. Our results suggest that the activity and/or expression of major P450 and UGT enzymes is modulated by MSBE and that potential herb-drugs interactions could arise after a combined intake of this extract with conventional medicines. Therefore, the potential safety risks of this natural product derived by altering the ADMET properties of co-administered drugs should be examined. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Identification and characterization of naturally occurring inhibitors against UDP-glucuronosyltransferase 1A1 in Fructus Psoraleae (Bu-gu-zhi)

    International Nuclear Information System (INIS)

    Wang, Xin-Xin; Lv, Xia; Li, Shi-Yang; Hou, Jie; Ning, Jing; Wang, Jia-Yue; Cao, Yun-Feng; Ge, Guang-Bo; Guo, Bin; Yang, Ling

    2015-01-01

    As an edible traditional Chinese herb, Fructus psoraleae (FP) has been widely used in Asia for the treatment of vitiligo, bone fracture and osteoporosis. Several cases on markedly elevated bilirubin and acute liver injury following administration of FP and its related proprietary medicine have been reported, but the mechanism in FP-associated toxicity has not been well investigated yet. This study aimed to investigate the inhibitory effects of FP extract and its major constituents against human UDP-glucuronosyltransferase 1A1 (UGT1A1), the key enzyme responsible for metabolic elimination of bilirubin. To this end, N-(3-carboxy propyl)-4-hydroxy-1,8-naphthalimide (NCHN), a newly developed specific fluorescent probe for UGT1A1, was used to evaluate the inhibitory effects of FP extract or its fractions in human liver microsomes (HLM), while LC-UV fingerprint and UGT1A1 inhibition profile were combined to identity and characterize the naturally occurring inhibitors of UGT1A1 in FP. Our results demonstrated that both the extract of FP and five major components of FP displayed evident inhibitory effects on UGT1A1 in HLM. Among these five identified naturally occurring inhibitors, bavachin and corylifol A were found to be strong inhibitors of UGT1A1 with the inhibition kinetic parameters (K i ) values lower than 1 μM, while neobavaisoflavone, isobavachalcone, and bavachinin displayed moderate inhibitory effects against UGT1A1 in HLM, with the K i values ranging from 1.61 to 9.86 μM. These findings suggested that FP contains natural compounds with potent inhibitory effects against human UGT1A1, which may be one of the important reasons for triggering FP-associated toxicity, including elevated bilirubin levels and liver injury. - Graphical abstract: LC-UV fingerprint and UGT1A1 inhibition profiles were combined to identity and characterize the natural inhibitors of UGT1A1 in F. psoraleae for the first time. Five major components in F. psoraleae were identified as strong

  9. Identification and characterization of naturally occurring inhibitors against UDP-glucuronosyltransferase 1A1 in Fructus Psoraleae (Bu-gu-zhi)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Xin [Liaoning Medical University, Jinzhou, Liaoning (China); Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Lv, Xia; Li, Shi-Yang [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Hou, Jie [Dalian Medical University, Dalian 116044 (China); Ning, Jing [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Dalian Medical University, Dalian 116044 (China); Wang, Jia-Yue [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Cao, Yun-Feng [Liaoning Medical University, Jinzhou, Liaoning (China); Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Ge, Guang-Bo, E-mail: geguangbo@dicp.ac.cn [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Guo, Bin, E-mail: jyguobin@126.com [Liaoning Medical University, Jinzhou, Liaoning (China); Yang, Ling [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Jiangxi University of Traditional Chinese Medicine, Nanchang 330006 (China)

    2015-11-15

    As an edible traditional Chinese herb, Fructus psoraleae (FP) has been widely used in Asia for the treatment of vitiligo, bone fracture and osteoporosis. Several cases on markedly elevated bilirubin and acute liver injury following administration of FP and its related proprietary medicine have been reported, but the mechanism in FP-associated toxicity has not been well investigated yet. This study aimed to investigate the inhibitory effects of FP extract and its major constituents against human UDP-glucuronosyltransferase 1A1 (UGT1A1), the key enzyme responsible for metabolic elimination of bilirubin. To this end, N-(3-carboxy propyl)-4-hydroxy-1,8-naphthalimide (NCHN), a newly developed specific fluorescent probe for UGT1A1, was used to evaluate the inhibitory effects of FP extract or its fractions in human liver microsomes (HLM), while LC-UV fingerprint and UGT1A1 inhibition profile were combined to identity and characterize the naturally occurring inhibitors of UGT1A1 in FP. Our results demonstrated that both the extract of FP and five major components of FP displayed evident inhibitory effects on UGT1A1 in HLM. Among these five identified naturally occurring inhibitors, bavachin and corylifol A were found to be strong inhibitors of UGT1A1 with the inhibition kinetic parameters (K{sub i}) values lower than 1 μM, while neobavaisoflavone, isobavachalcone, and bavachinin displayed moderate inhibitory effects against UGT1A1 in HLM, with the K{sub i} values ranging from 1.61 to 9.86 μM. These findings suggested that FP contains natural compounds with potent inhibitory effects against human UGT1A1, which may be one of the important reasons for triggering FP-associated toxicity, including elevated bilirubin levels and liver injury. - Graphical abstract: LC-UV fingerprint and UGT1A1 inhibition profiles were combined to identity and characterize the natural inhibitors of UGT1A1 in F. psoraleae for the first time. Five major components in F. psoraleae were identified as

  10. The influence of charge and the distribution of charge in the polar region of phospholipids on the activity of UDP-glucuronosyltransferase.

    Science.gov (United States)

    Zakim, D; Eibl, H

    1992-07-05

    Studies of the mechanism of lipid-induced regulation of the microsomal enzyme UDP-glucuronosyltransferase have been extended by examining the influence of charge within the polar region on the ability of lipids to activate delipidated pure enzyme. The effects of net negative charge, of charge separation in phosphocholine, and of the distribution of charge in the polar region of lipids were studied using the GT2p isoform isolated from pig liver. Prior experiments have shown that lipids with net negative charge inhibit the enzyme (Zakim, D., Cantor, M., and Eibl, H. (1988) J. Biol. Chem. 263, 5164-5169). The current experiments show that the extent of inhibition on a molar basis increases as the net negative charge increases from -1 to -2. The inhibitory effect of negatively charged lipids is on the functional state of the enzyme and is not due to electrostatic repulsion of negatively charged substrates of the enzyme. Although the inhibitory effect of net negative charge is removed when negative charge is balanced by a positive charge due to a quaternary nitrogen, neutrality of the polar region is not a sufficient condition for activation of the enzyme. In addition to a balance of charge between Pi and the quaternary nitrogen, the distance between the negative and positive charges and the orientation of the dipole created by them are critical for activation of GT2p. The negative and positive charges must be separated by the equivalent of three -CH2- groups for optimal activation by a lipid. Shortening this distance by one -CH2- unit leads to a lipid that is ineffective in activating the enzyme. Reversal of the orientation of the dipole in which the negative charge is on the polymethylene side of the lipid-water interface and the positive charge extends into water also produces a lipid that is not effective for activating GT2p. On the other hand, lipids with phosphoserine as the polar region, which has the "normal" P-N distance but carries a net negative charge, do

  11. Effects of aqueous extract of Ruta graveolens and its ingredients on cytochrome P450, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH-quinone oxidoreductase in mice

    Directory of Open Access Journals (Sweden)

    Yune-Fang Ueng

    2015-09-01

    Full Text Available Ruta graveolens (the common rue has been used for various therapeutic purposes, including relief of rheumatism and treatment of circulatory disorder. To elucidate the effects of rue on main drug-metabolizing enzymes, effects of an aqueous extract of the aerial part of rue and its ingredients on cytochrome P450 (P450/CYP, uridine diphosphate (UDP-glucuronosyltransferase, and reduced nicotinamide adenine dinucleotide (phosphate (NAD(PH:quinone oxidoreductase were studied in C57BL/6JNarl mice. Oral administration of rue extract to males increased hepatic Cyp1a and Cyp2b activities in a dose-dependent manner. Under a 7-day treatment regimen, rue extract (0.5 g/kg induced hepatic Cyp1a and Cyp2b activities and protein levels in males and females. This treatment increased hepatic UDP-glucuronosyltransferase activity only in males. However, NAD(PH:quinone oxidoreductase activity remained unchanged. Based on the contents of rutin and furanocoumarins of mouse dose of rue extract, rutin increased hepatic Cyp1a activity and the mixture of furanocoumarins (Fmix increased Cyp2b activities in males. The mixture of rutin and Fmix increased Cyp1a and Cyp2b activities. These results revealed that rutin and Fmix contributed at least in part to the P450 induction by rue.

  12. Modulation of hyaluronan synthase activity in cellular membrane fractions.

    Science.gov (United States)

    Vigetti, Davide; Genasetti, Anna; Karousou, Evgenia; Viola, Manuela; Clerici, Moira; Bartolini, Barbara; Moretto, Paola; De Luca, Giancarlo; Hascall, Vincent C; Passi, Alberto

    2009-10-30

    Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in eukaryotic cells and addressed the question of HAS activity during intracellular protein trafficking. We prepared three cellular fractions: plasma membrane, cytosol (containing membrane proteins mainly from the endoplasmic reticulum and Golgi), and nuclei. After incubation with UDP-sugar precursors, newly synthesized HA was quantified by polyacrylamide gel electrophoresis of fluorophore-labeled saccharides and high performance liquid chromatography. This new method measured HAS activity not only in the plasma membrane fraction but also in the cytosolic membranes. This new technique was used to evaluate the effects of 4-methylumbeliferone, phorbol 12-myristate 13-acetate, interleukin 1beta, platelet-derived growth factor BB, and tunicamycin on HAS activities. We found that HAS activity can be modulated by post-translational modification, such as phosphorylation and N-glycosylation. Interestingly, we detected a significant increase in HAS activity in the cytosolic membrane fraction after tunicamycin treatment. Since this compound is known to induce HA cable structures, this result links HAS activity alteration with the capability of the cell to promote HA cable formation.

  13. Purification and characterization of hyaluronic acid produced by Streptococcus zooepidemicus strain 3523-7

    Directory of Open Access Journals (Sweden)

    K. Jagadeeswara Reddy

    2013-01-01

    Full Text Available Hyaluronic acid (HA is a hydrated gel and comprises repeating units of glucuronic acid and N-acetylglucosamine. Production and recovery of HA has gained great importance due to its vast clinical applications. In pursuit of obtaining highly pure HA, we have developed a fed-batch fermentation process using Streptococcus zooepidemicus in a 25 L bioreactor that resulted in a maximum yield of 2.3 g/L HA. In addition, we have devised an efficient method for separation and recovery of hyaluronic acid from a highly viscous broth by treating with trichloroacetic acid (0.1% and charcoal (1-2%, passing through filtration (0.45 μm and ultrafiltration that resulted in recovery of 72.2% of clinical grade HA with molecular weight of 2.5×106 Da. We have also characterized our purified HA using FTIR and NMR spectroscopy. These studies revealed the similarity in both the FTIR spectrum as well as NMR spectrum of both reference standard and purified HA from S. zooepidemicus indicating that the reported process is more efficient in terms of better yield and high quality (99.2%.

  14. Uptake of acidic and basic sugar derivatives in Lemna gibba G1

    International Nuclear Information System (INIS)

    Sanz, A.; Ullrich, C.I.

    1989-01-01

    The uptake of acidic and basic sugar derivatives in Lemna gibba L. was studied. Uronic acids applied to the experimental solution induced a small decrease of the membrane potential. After incubation of the plants in a 0.1 millimolar solution of these substrates, no decrease in the concentration of reducing groups in the external solution was detected. Respiration increased by 31% with 50 millimolar galacturonic acid, whereas no effect was found with the same concentration of glucuronic acid. Glucosamine caused a considerable concentration-dependent membrane depolarization. ( 14 C)glucosamine uptake followed Michaelis-Menten kinetics together with a linear component. Influx of this substrate was inhibited by glucose but the type of competition could not be clearly distinguished. Glucosamine, 50 millimolar, inhibited the respiration rate by 30%. The glucosamine uptake was pH-dependent, with maximum uptake at around pH 7. Lack of enhancement of uptake by low pH as well as the permanent membrane depolarization suggest a uniport mechanism for the charged species of the substrate and an electroneutral diffusion of the uncharged species

  15. Structure and Mechanism of Staphylococcus aureus TarS, the Wall Teichoic Acid β-glycosyltransferase Involved in Methicillin Resistance.

    Directory of Open Access Journals (Sweden)

    Solmaz Sobhanifar

    2016-12-01

    Full Text Available In recent years, there has been a growing interest in teichoic acids as targets for antibiotic drug design against major clinical pathogens such as Staphylococcus aureus, reflecting the disquieting increase in antibiotic resistance and the historical success of bacterial cell wall components as drug targets. It is now becoming clear that β-O-GlcNAcylation of S. aureus wall teichoic acids plays a major role in both pathogenicity and antibiotic resistance. Here we present the first structure of S. aureus TarS, the enzyme responsible for polyribitol phosphate β-O-GlcNAcylation. Using a divide and conquer strategy, we obtained crystal structures of various TarS constructs, mapping high resolution overlapping N-terminal and C-terminal structures onto a lower resolution full-length structure that resulted in a high resolution view of the entire enzyme. Using the N-terminal structure that encapsulates the catalytic domain, we furthermore captured several snapshots of TarS, including the native structure, the UDP-GlcNAc donor complex, and the UDP product complex. These structures along with structure-guided mutants allowed us to elucidate various catalytic features and identify key active site residues and catalytic loop rearrangements that provide a valuable platform for anti-MRSA drug design. We furthermore observed for the first time the presence of a trimerization domain composed of stacked carbohydrate binding modules, commonly observed in starch active enzymes, but adapted here for a poly sugar-phosphate glycosyltransferase.

  16. [Analysis of monosaccharides and uronic acids in polysaccharides by pre-column derivatization with p-aminobenzoic acid and high performance liquid chromatography].

    Science.gov (United States)

    Hao, Guitang; Chen, Shangwei; Zhu, Song; Yin, Hongping; Dai, Jun; Cao, Yuhua

    2007-01-01

    An ion-pair reversed-phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of carbohydrate and uronic acids was developed. p-Aminobenzoic acid (p-AMBA) was used for pre-column derivatization of the analytes, enabling fluorescence (lambda(ex) = 313 nm, lambda(em) = 358 nm) or ultraviolet (UV at 303 nm) detection. Reaction conditions such as reaction temperature and reaction time were optimized. Atlantis dC18 column with hydrophilic end capping was selected for the separation of derivatives. Effects of mobile phase compositions such as ion pairs and their concentrations and pH on the retention behaviors and separation results of 9 monosaccharides and 2 uronic acids were investigated. Derivatives of fructose, galactose, glucose, mannose, xylose, arabinose, ribose, galacturonic acid, fucose, glucuronic acid and rhamnose were separated within 42 min, applying tetrabutyl ammonium hydrogen bisulfate (TBAHSO4) as the ion pair reagent. The detection limits were between 3.38 x 10(-8) mol/L and 176 x 10(-8) mol/L for fluorescence detection and between 2.55 x 10(-7) mol/L and 13.4 x 10(-7) mol/L for UV detection. Good linearities were obtained with correlation coefficients (r2) above 0.99. The relative standard deviations (RSDs) of the peak area of the derivatives in 12 - 51 h after derivatization were from 2.5% to 3.9%. This method has been applied for the determination of mono-/disaccharides and uronic acids in spirulina polysaccharide after dissolved in trifluoroacetic acid solution (2 mol/L). The results showed this method is suitable for the analysis of monosaccharide compositions in polysaccharides.

  17. Aspartic acid

    Science.gov (United States)

    ... we eat. Aspartic acid is also called asparaginic acid. Aspartic acid helps every cell in the body work. It ... release Normal nervous system function Plant sources of aspartic acid include: avocado, asparagus, and molasses. Animal sources of ...

  18. Rare ginsenoside Ia synthesized from F1 by cloning and overexpression of the UDP-glycosyltransferase gene from Bacillus subtilis: synthesis, characterization, and in vitro melanogenesis inhibition activity in BL6B16 cells.

    Science.gov (United States)

    Wang, Dan-Dan; Jin, Yan; Wang, Chao; Kim, Yeon-Ju; Perez, Zuly Elizabeth Jimenez; Baek, Nam In; Mathiyalagan, Ramya; Markus, Josua; Yang, Deok-Chun

    2018-01-01

    Ginsenoside F1 has been described to possess skin-whitening effects on humans. We aimed to synthesize a new ginsenoside derivative from F1 and investigate its cytotoxicity and melanogenesis inhibitory activity in B16BL6 cells using recombinant glycosyltransferase enzyme. Glycosylation has the advantage of synthesizing rare chemical compounds from common compounds with great ease. UDP-glycosyltransferase (BSGT1) gene from Bacillus subtilis was selected for cloning. The recombinant glycosyltransferase enzyme was purified, characterized, and utilized to enzymatically transform F1 into its derivative. The new product was characterized by NMR techniques and evaluated by MTT, melanin count, and tyrosinase inhibition assay. The new derivative was identified as (20 S )-3 β ,6 α ,12 β ,20-tetrahydroxydammar-24-ene-20- O - β -D-glucopyranosyl-3- O - β -D-glucopyranoside (ginsenoside Ia), which possesses an additional glucose linked into the C-3 position of substrate F1. Ia had been previously reported; however, no in vitro biological activity was further examined. This study focused on the mass production of arduous ginsenoside Ia from accessible F1 and its inhibitory effect of melanogenesis in B16BL6 cells. Ia showed greater inhibition of melanin and tyrosinase at 100 μmol/L than F1 and arbutin. These results suggested that Ia decreased cellular melanin synthesis in B16BL6 cells through downregulation of tyrosinase activity. To our knowledge, this is the first study to report on the mass production of rare ginsenoside Ia from F1 using recombinant UDP-glycosyltransferase isolated from B. subtillis and its superior melanogenesis inhibitory activity in B16BL6 cells as compared to its precursor. In brief, ginsenoside Ia can be applied for further study in cosmetics.

  19. Characterization of ppGalNAc-T18, a member of the vertebrate-specific Y subfamily of UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferases.

    Science.gov (United States)

    Li, Xing; Wang, Jing; Li, Wei; Xu, Yingjiao; Shao, Dong; Xie, Yinyin; Xie, Wenxian; Kubota, Tomomi; Narimatsu, Hisashi; Zhang, Yan

    2012-05-01

    The first step of mucin-type O-glycosylation is catalyzed by members of the UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (ppGalNAc-T; EC 2.4.1.41) family. Each member of this family has unique substrate specificity and expression profiles. In this report, we describe a new subfamily of ppGalNAc-Ts, designated the Y subfamily. The Y subfamily consists of four members, ppGalNAc-T8, -T9, -T17 and -T18, in which the conserved YDX(5)WGGENXE sequence in the Gal/GalNAc-T motif of ppGalNAc-Ts is mutated to LDX(5)YGGENXE. Phylogenetic analysis revealed that the Y subfamily members only exist in vertebrates. All four Y subfamily members lack in vitro GalNAc-transferase activity toward classical substrates possibly because of the UDP-GalNAc-binding pocket mutants. However, ppGalNAc-T18, the newly identified defining member, was localized in the endoplasmic reticulum rather than the Golgi apparatus in lung carcinoma cells. The knockdown of ppGalNAc-T18 altered cell morphology, proliferation potential and changed cell O-glycosylation. ppGalNAc-T18 can also modulate the in vitro GalNAc-transferase activity of ppGalNAc-T2 and -T10, suggesting that it may be a chaperone-like protein. These findings suggest that the new Y subfamily of ppGalNAc-Ts plays an important role in protein glycosylation; characterizing their functions will provide new insight into the role of ppGalNAc-Ts.

  20. Metabolism of clofibric acid in zebrafish embryos (Danio rerio) as determined by liquid chromatography-high resolution-mass spectrometry.

    Science.gov (United States)

    Brox, Stephan; Seiwert, Bettina; Haase, Nora; Küster, Eberhard; Reemtsma, Thorsten

    2016-01-01

    The zebrafish embryo (ZFE) is increasingly used in ecotoxicology research but detailed knowledge of its metabolic potential is still limited. This study focuses on the xenobiotic metabolism of ZFE at different life-stages using the pharmaceutical compound clofibric acid as study compound. Liquid chromatography with quadrupole-time-of-flight mass spectrometry (LC-QToF-MS) is used to detect and to identify the transformation products (TPs). In screening experiments, a total of 18 TPs was detected and structure proposals were elaborated for 17 TPs, formed by phase I and phase II metabolism. Biotransformation of clofibric acid by the ZFE involves conjugation with sulfate or glucuronic acid, and, reported here for the first time, with carnitine, taurine, and aminomethanesulfonic acid. Further yet unknown cyclization products were identified using non-target screening that may represent a new detoxification pathway. Sulfate containing TPs occurred already after 3h of exposure (7hpf), and from 48h of exposure (52hpf) onwards, all TPs were detected. The detection of these TPs indicates the activity of phase I and phase II enzymes already at early life-stages. Additionally, the excretion of one TP into the exposure medium was observed. The results of this study outline the high metabolic potential of the ZFE with respect to the transformation of xenobiotics. Similarities but also differences to other test systems were observed. Biotransformation of test chemicals in toxicity testing with ZFE may therefore need further consideration. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Genome-Wide Identification and Expression Analysis of the UGlcAE Gene Family in Tomato

    Directory of Open Access Journals (Sweden)

    Xing Ding

    2018-05-01

    Full Text Available The UGlcAE has the capability of interconverting UDP-d-galacturonic acid and UDP-d-glucuronic acid, and UDP-d-galacturonic acid is an activated precursor for the synthesis of pectins in plants. In this study, we identified nine UGlcAE protein-encoding genes in tomato. The nine UGlcAE genes that were distributed on eight chromosomes in tomato, and the corresponding proteins contained one or two trans-membrane domains. The phylogenetic analysis showed that SlUGlcAE genes could be divided into seven groups, designated UGlcAE1 to UGlcAE6, of which the UGlcAE2 were classified into two groups. Expression profile analysis revealed that the SlUGlcAE genes display diverse expression patterns in various tomato tissues. Selective pressure analysis indicated that all of the amino acid sites of SlUGlcAE proteins are undergoing purifying selection. Fifteen stress-, hormone-, and development-related elements were identified in the upstream regions (0.5 kb of these SlUGlcAE genes. Furthermore, we investigated the expression patterns of SlUGlcAE genes in response to three hormones (indole-3-acetic acid (IAA, gibberellin (GA, and salicylic acid (SA. We detected firmness, pectin contents, and expression levels of UGlcAE family genes during the development of tomato fruit. Here, we systematically summarize the general characteristics of the SlUGlcAE genes in tomato, which could provide a basis for further function studies of tomato UGlcAE genes.

  2. Monosaccharide composition of acidic gum exudates from Indian Acacia tortilis ssp. raddiana (Savi) Brenan.

    Science.gov (United States)

    Lakhera, Ajeet Kumar; Kumar, Vineet

    2017-01-01

    Acacia tortilis ssp. raddiana (Savi) Brenan commonly known as Israeli Babool has contributed immensely for sand dunes management in Indian desert leading to wind erosion control and increased biological productivity. The species is extensively used in traditional medicine system for a number of therapeutic applications and as nutraceutical. The polysaccharide was isolated in 43.6% yield from gum exudates. The monosaccharides, L-arabinose, D-galactose D-glucose, L-rhamnose and D-mannose were determined in molar ratio of 78.1%, 18.64%, 0.60%, 1.71% and 0.74% respectively. The molar ratio of uronic acids was studied using diverse spectrophotometric methods and compared with GLC. The content of D-galacturonic acid and D-glucuronic was determined as 3.88% and 4.35% respectively by GLC. The results were compared with the spectrophotometric methods. The results using DMP as chromogenic reagent are closer to that obtained by GLC. Structural analysis of the polysaccharide may provide scientific basis for nutraceutical, pharmaceutical and biological applications of gum exudates from A. tortilis, which is extensively planted in India. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Differentiating chondroitin sulfate glycosaminoglycans using collision-induced dissociation; uronic acid cross-ring diagnostic fragments in a single stage of tandem mass spectrometry.

    Science.gov (United States)

    Kailemia, Muchena J; Patel, Anish B; Johnson, Dane T; Li, Lingyun; Linhardt, Robert J; Amster, I Jonathan

    2015-01-01

    The stereochemistry of the hexuronic acid residues of the structure of glycosaminoglycans (GAGs) is a key feature that affects their interactions with proteins and other biological functions. Electron based tandem mass spectrometry methods, in particular electron detachment dissociation (EDD), have been able to distinguish glucuronic acid (GlcA) from iduronic acid (IdoA) residues in some heparan sulfate tetrasaccharides by producing epimer-specific fragments. Similarly, the relative abundance of glycosidic fragment ions produced by collision-induced dissociation (CID) or EDD has been shown to correlate with the type of hexuronic acid present in chondroitin sulfate GAGs. The present work examines the effect of charge state and degree of sodium cationization on the CID fragmentation products that can be used to distinguish GlcA and IdoA containing chondroitin sulfate A and dermatan sulfate chains. The cross-ring fragments (2,4)A(n) and (0,2)X(n) formed within the hexuronic acid residues are highly preferential for chains containing GlcA, distinguishing it from IdoA. The diagnostic capability of the fragments requires the selection of a molecular ion and fragment ions with specific ionization characteristics, namely charge state and number of ionizable protons. The ions with the appropriate characteristics display diagnostic properties for all the chondroitin sulfate and dermatan sulfate chains (degree of polymerization of 4-10) studied.

  4. Enzymatic conversion of bilirubin monoglucuronide to diglucuronide by rat liver plasma membranes

    NARCIS (Netherlands)

    Jansen, P. L.; Chowdhury, J. R.; Fischberg, E. B.; Arias, I. M.

    1977-01-01

    Formation of bilirubin monoglucuronide from unconjugated bilirubin requires a microsomal enzyme, UDP-glucuronate glucuronyltransferase (EC 2.4.1.17). Conversion of bilirubin monoglucuronide to bilirubin diglucuronide, the major bilirubin conjugate in bile, was studied in subcellular fractions of rat

  5. Acid Rain

    Science.gov (United States)

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  6. UDP-Glycosyltransferases from the UGT73C Subfamily in Barbarea vulgaris Catalyze Sapogenin 3-O-Glucosylation in Saponin-Mediated Insect Resistance1[W][OA

    Science.gov (United States)

    Augustin, Jörg M.; Drok, Sylvia; Shinoda, Tetsuro; Sanmiya, Kazutsuka; Nielsen, Jens Kvist; Khakimov, Bekzod; Olsen, Carl Erik; Hansen, Esben Halkjær; Kuzina, Vera; Ekstrøm, Claus Thorn; Hauser, Thure; Bak, Søren

    2012-01-01

    Triterpenoid saponins are bioactive metabolites that have evolved recurrently in plants, presumably for defense. Their biosynthesis is poorly understood, as is the relationship between bioactivity and structure. Barbarea vulgaris is the only crucifer known to produce saponins. Hederagenin and oleanolic acid cellobioside make some B. vulgaris plants resistant to important insect pests, while other, susceptible plants produce different saponins. Resistance could be caused by glucosylation of the sapogenins. We identified four family 1 glycosyltransferases (UGTs) that catalyze 3-O-glucosylation of the sapogenins oleanolic acid and hederagenin. Among these, UGT73C10 and UGT73C11 show highest activity, substrate specificity and regiospecificity, and are under positive selection, while UGT73C12 and UGT73C13 show lower substrate specificity and regiospecificity and are under purifying selection. The expression of UGT73C10 and UGT73C11 in different B. vulgaris organs correlates with saponin abundance. Monoglucosylated hederagenin and oleanolic acid were produced in vitro and tested for effects on P. nemorum. 3-O-β-d-Glc hederagenin strongly deterred feeding, while 3-O-β-d-Glc oleanolic acid only had a minor effect, showing that hydroxylation of C23 is important for resistance to this herbivore. The closest homolog in Arabidopsis thaliana, UGT73C5, only showed weak activity toward sapogenins. This indicates that UGT73C10 and UGT73C11 have neofunctionalized to specifically glucosylate sapogenins at the C3 position and demonstrates that C3 monoglucosylation activates resistance. As the UGTs from both the resistant and susceptible types of B. vulgaris glucosylate sapogenins and are not located in the known quantitative trait loci for resistance, the difference between the susceptible and resistant plant types is determined at an earlier stage in saponin biosynthesis. PMID:23027665

  7. Cyclic diguanylic acid and cellulose synthesis in Agrobacterium tumefaciens

    International Nuclear Information System (INIS)

    Amikam, D.; Benziman, M.

    1989-01-01

    The occurrence of the novel regulatory nucleotide bis(3',5')-cyclic diguanylic acid (c-di-GMP) and its relation to cellulose biogenesis in the plant pathogen Agrobacterium tumefaciens was studied. c-di-GMP was detected in acid extracts of 32 P-labeled cells grown in various media, and an enzyme responsible for its formation from GTP was found to be present in cell-free preparations. Cellulose synthesis in vivo was quantitatively assessed with [ 14 C]glucose as a tracer. The organism produced cellulose during growth in the absence of plant cells, and this capacity was retained in resting cells. Synthesis of a cellulosic product from UDP-glucose in vitro with membrane preparations was markedly stimulated by c-di-GMP and its precursor GTP and was further enhanced by Ca2+. The calcium effect was attributed to inhibition of a c-di-GMP-degrading enzyme shown to be present in the cellulose synthase-containing membranes

  8. Effect of a New Prokinetic Agent DA-9701 Formulated with Corydalis Tuber and Pharbitidis Semen on Cytochrome P450 and UDP-Glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Hye Young Ji

    2012-01-01

    Full Text Available DA-9701 is a new botanical drug composed of the extracts of Corydalis tuber and Pharbitidis semen, and it is used as an oral therapy for the treatment of functional dyspepsia in Korea. The inhibitory potentials of DA-9701 and its component herbs, Corydalis tuber and Pharbitidis semen, on the activities of seven major human cytochrome P450 (CYP enzymes and four UDP-glucuronosyltransferase (UGT enzymes in human liver microsomes were investigated using liquid chromatography-tandem mass spectrometry. DA-9701 and Corydalis tuber extract slightly inhibited UGT1A1-mediated etoposide glucuronidation, with 50% inhibitory concentration (IC50 values of 188 and 290 μg/mL, respectively. DA-9701 inhibited CYP2D6-catalyzed bufuralol 1′-hydroxylation with an inhibition constant (Ki value of 6.3 μg/mL in a noncompetitive manner. Corydalis tuber extract competitively inhibited CYP2D6-mediated bufuralol 1′-hydroxylation, with a Ki value of 3.7 μg/mL, whereas Pharbitidis semen extract showed no inhibition. The volume in which the dose could be diluted to generate an IC50 equivalent concentration (volume per dose index value of DA-9701 for inhibition of CYP2D6 activity was 1.16 L/dose, indicating that DA-9701 may not be a potent CYP2D6 inhibitor. Further clinical studies are warranted to evaluate the in vivo extent of the observed in vitro interactions.

  9. High Expression of UGT1A1/1A6 in Monkey Small Intestine: Comparison of Protein Expression Levels of Cytochromes P450, UDP-Glucuronosyltransferases, and Transporters in Small Intestine of Cynomolgus Monkey and Human.

    Science.gov (United States)

    Akazawa, Takanori; Uchida, Yasuo; Miyauchi, Eisuke; Tachikawa, Masanori; Ohtsuki, Sumio; Terasaki, Tetsuya

    2018-01-02

    Cynomolgus monkeys have been widely used for the prediction of drug absorption in humans. The purpose of this study was to clarify the regional protein expression levels of cytochromes P450 (CYPs), UDP-glucuronosyltransferases (UGTs), and transporters in small intestine of cynomolgus monkey using liquid chromatography-tandem mass spectrometry, and to compare them with the corresponding levels in human. UGT1A1 in jejunum and ileum were >4.57- and >3.11-fold and UGT1A6 in jejunum and ileum were >16.1- and >8.57-fold, respectively, more highly expressed in monkey than in human. Also, jejunal expression of monkey CYP3A8 (homologue of human CYP3A4) was >3.34-fold higher than that of human CYP3A4. Among apical drug efflux transporters, BCRP showed the most abundant expression in monkey and human, and the expression levels of BCRP in monkey and human were >1.74- and >1.25-fold greater than those of P-gp and >2.76- and >4.50-fold greater than those of MRP2, respectively. These findings should be helpful to understand species differences of the functions of CYPs, UGTs, and transporters between monkey and human. The UGT1A1/1A6 data would be especially important because it is difficult to identify isoforms responsible for species differences of intestinal glucuronidation by means of functional studies due to overlapping substrate specificity.

  10. Identification of a novel UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Vibrio fischeri that confers high fosfomycin resistance in Escherichia coli

    Digital Repository Service at National Institute of Oceanography (India)

    Kumar, S.; Parvathi, A.; Hernandez, R.L.; Cadle, K.M.; Varela, M.F.

    -positive and Gram-negative bacteria. The antibiotic is used to treat uncomplicated urinary tract infections (UTIs) caused by E. coli and Enterococcus faecalis world wide (Falagas et al. 2008). Some pathogenic bacteria such as Mycobacterium tuberculosis...A proteins are naturally resistant to fosfomycin, such as in the case of Mycobacterium tuberculosis and Chlamydia trachomatis (DeSmet et al. 1999; McCoy et al. 2003). We compared the deduced amino acid sequence of V. fischeri MurA with the homologous...

  11. Amino acids

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  12. Valproic Acid

    Science.gov (United States)

    ... acid is in a class of medications called anticonvulsants. It works by increasing the amount of a ... older (about 1 in 500 people) who took anticonvulsants such as valproic acid to treat various conditions ...

  13. Ascorbic Acid

    Science.gov (United States)

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  14. Aminocaproic Acid

    Science.gov (United States)

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  15. Ethacrynic Acid

    Science.gov (United States)

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  16. Biosynthesis of heparin. Effects of n-butyrate on cultured mast cells

    International Nuclear Information System (INIS)

    Jacobsson, K.G.; Riesenfeld, J.; Lindahl, U.

    1985-01-01

    Murine mastocytoma cells were incubated in vitro with inorganic [ 35 S]sulfate, in the absence or presence of 2.5 mM n-butyrate, and labeled heparin was isolated. The polysaccharide produced in the presence of butyrate showed a lower charge density on anion exchange chromatography than did the control material and a 3-fold increased proportion of components with high affinity for antithrombin. Structural analysis of heparin labeled with [ 3 H] glucosamine in the presence of butyrate showed that approximately 35% of the glucosamine units were N-acetylated, as compared to approximately 10% in the control material; the nonacetylated glucosamine residues were N-sulfated. The presence of butyrate thus leads to an inhibition of the N-deacetylation/N-sulfation process in heparin biosynthesis, along with an augmented formation of molecules with high affinity for antithrombin. Preincubation of the mastocytoma cells with butyrate was required for manifestation of either effect; when the preincubation period was reduced from 24 to 10 h the effects of butyrate were no longer observed. A polysaccharide formed on incubating mastocytoma microsomal fraction with UDP-[ 3 H]glucuronic acid, UDP-N-acetylglucosamine, and 3'-phosphoadenylylsulfate in the presence of 5 mM butyrate showed the same N-acetyl/N-sulfate ratio as did the corresponding control polysaccharide, produced in the absence of butyrate. These findings suggest that the effect of butyrate on heparin biosynthesis depends on the integrity of the cell

  17. Recombinant Plants Provide a New Approach to the Production of Bacterial Polysaccharide for Vaccines

    Science.gov (United States)

    Smith, Claire M.; Fry, Stephen C.; Gough, Kevin C.; Patel, Alexandra J. F.; Glenn, Sarah; Goldrick, Marie; Roberts, Ian S.; Andrew, Peter W.

    2014-01-01

    Bacterial polysaccharides have numerous clinical or industrial uses. Recombinant plants could offer the possibility of producing bacterial polysaccharides on a large scale and free of contaminating bacterial toxins and antigens. We investigated the feasibility of this proposal by cloning and expressing the gene for the type 3 synthase (cps3S) of Streptococcus pneumoniae in Nicotinia tabacum, using the pCambia2301 vector and Agrobacterium tumefaciens-mediated gene transfer. In planta the recombinant synthase polymerised plant-derived UDP-glucose and UDP-glucuronic acid to form type 3 polysaccharide. Expression of the cps3S gene was detected by RT-PCR and production of the pneumococcal polysaccharide was detected in tobacco leaf extracts by double immunodiffusion, Western blotting and high-voltage paper electrophoresis. Because it is used a component of anti-pneumococcal vaccines, the immunogenicity of the plant-derived type 3 polysaccharide was tested. Mice immunised with extracts from recombinant plants were protected from challenge with a lethal dose of pneumococci in a model of pneumonia and the immunised mice had significantly elevated levels of serum anti-pneumococcal polysaccharide antibodies. This study provides the proof of the principle that bacterial polysaccharide can be successfully synthesised in plants and that these recombinant polysaccharides could be used as vaccines to protect against life-threatening infections. PMID:24498433

  18. Alkaline/peracetic acid as a pretreatment of lignocellulosic biomass for ethanol fuel production

    Science.gov (United States)

    Teixeira, Lincoln Cambraia

    Peracetic acid is a lignin oxidation pretreatment with low energy input by which biomass can be treated in a silo type system for improving enzymatic digestibility of lignocellulosic materials for ethanol production. Experimentally, ground hybrid poplar wood and sugar cane bagasse are placed in plastic bags and a peracetic acid solution is added to the biomass in different concentrations based on oven-dry biomass. The ratio of solution to biomass is 6:1; after initial mixing of the resulting paste, a seven-day storage period at about 20°C is used in this study. As a complementary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetyl content in the biomass is been performed before addition of peracetic acid. The alkaline solutions are added to the biomass in a ratio of 14:1 solution to biomass; the slurry is mixed for 24 hours at ambient temperature. The above procedures give high xylan content substrates. Consequently, xylanase/beta-glucosidase combinations are more effective than cellulase preparations in hydrolyzing these materials. The pretreatment effectiveness is evaluated using standard enzymatic hydrolysis and simultaneous saccharification and cofermentation (SSCF) procedures. Hybrid poplar wood pretreated with 15 and 21% peracetic acid based on oven-dry weight of wood gives glucan conversion yields of 76.5 and 98.3%, respectively. Sugar cane bagasse pretreated with the same loadings gives corresponding yields of 85.9 and 93.1%. Raw wood and raw bagasse give corresponding yields of 6.8 and 28.8%, respectively. The combined 6% NaOH/15% peracetic acid pretreatments increase the glucan conversion yields from 76.5 to 100.0% for hybrid poplar wood and from 85.9 to 97.6% for sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% are obtained from 6% NaOH/15% peracetic acid pretreated materials using recombinant Zymomonas mobilis CP4/pZB5. Peracetic acid

  19. A new method for the quantification of monosaccharides, uronic acids and oligosaccharides in partially hydrolyzed xylans by HPAEC-UV/VIS.

    Science.gov (United States)

    Lorenz, Dominic; Erasmy, Nicole; Akil, Youssef; Saake, Bodo

    2016-04-20

    A new method for the chemical characterization of xylans is presented, to overcome the difficulties in quantification of 4-O-methyl-α-D-glucuronic acid (meGlcA). In this regard, the hydrolysis behavior of xylans from beech and birch wood was investigated to obtain the optimum conditions for hydrolysis, using sulfuric acid. Due to varying linkage strengths and degradation, no general method for complete hydrolysis can be designed. Therefore, partial hydrolysis was applied, yielding monosaccharides and small meGlcA containing oligosaccharides. For a new method by HPAEC-UV/VIS, these samples were reductively aminated by 2-aminobenzoic acid. By quantification of monosaccharides and oligosaccharides, as well as comparison with borate-HPAEC and (13)C NMR-spectroscopy, we revealed that the concentrations meGlcA are significantly underestimated compared to conventional methods. The detected concentrations are 85.4% (beech) and 76.3% (birch) higher with the new procedure. Furthermore, the quantified concentrations of xylose were 9.3% (beech) and 6.5% (birch) higher by considering the unhydrolyzed oligosaccharides as well. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Well acidizing

    Energy Technology Data Exchange (ETDEWEB)

    Street, E H

    1980-01-23

    The apparatus relates in particular to a well-treating process in which an aqueous acid solution having a pH of < 2 is injected into a subterranean reservoir in a manner such that materials that contain ferric ions are present in the acid and, as the acid reacts within the reservoir and attains a pH exceeding 3, tend to be precipitated as ferric ion-containing solid materials that may plug the pores of the reservoir. Such a precipitation is prevented by dissolving in the acid solution an amount of 5-sulfosalicylic acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 0.5 to 3 but is less than enough to cause a significant salting-out of solid materials, and an amount of citric acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 3 to 6 but is less than enough to precipitate a significant amount of calcium citrate. The amount of the 5-sulfosalicylic acid may be from 0.01 to 0.05 moles/l and the amount of citric acid is from 0.001 to 0.009 moles/l. 11 claims.

  1. Amino acid and glucose metabolism in fed-batch CHO cell culture affects antibody production and glycosylation

    DEFF Research Database (Denmark)

    Fan, Yuzhou; Jimenez Del Val, Ioscani; Müller, Christian

    2015-01-01

    optimization, especially media optimization. Gaining knowledge on their interrelations could provide insight for obtaining higher immunoglobulin G (IgG) titer and better controlling glycosylationrelated product quality. In this work, different fed-batch processes with two chemically defined proprietary media......Fed-batch Chinese hamster ovary (CHO) cell culture is the most commonly used process for IgG production in the biopharmaceutical industry. Amino acid and glucose consumption, cell growth, metabolism, antibody titer, and N-glycosylation patterns are always the major concerns during upstream process...... and glutamine concentrations and uptake rates were positively correlated with intracellular UDP-Gal availability. All these findings are important for optimization of fed-batch culture for improving IgG production and directing glycosylation quality....

  2. Ibotenic acid and thioibotenic acid

    DEFF Research Database (Denmark)

    Hermit, Mette B; Greenwood, Jeremy R; Nielsen, Birgitte

    2004-01-01

    In this study, we have determined and compared the pharmacological profiles of ibotenic acid and its isothiazole analogue thioibotenic acid at native rat ionotropic glutamate (iGlu) receptors and at recombinant rat metabotropic glutamate (mGlu) receptors expressed in mammalian cell lines....... Thioibotenic acid has a distinct pharmacological profile at group III mGlu receptors compared with the closely structurally related ibotenic acid; the former is a potent (low microm) agonist, whereas the latter is inactive. By comparing the conformational energy profiles of ibotenic and thioibotenic acid...... with the conformations preferred by the ligands upon docking to mGlu1 and models of the other mGlu subtypes, we propose that unlike other subtypes, group III mGlu receptor binding sites require a ligand conformation at an energy level which is prohibitively expensive for ibotenic acid, but not for thioibotenic acid...

  3. Proteomic investigation into betulinic acid-induced apoptosis of human cervical cancer HeLa cells.

    Science.gov (United States)

    Xu, Tao; Pang, Qiuying; Zhou, Dong; Zhang, Aiqin; Luo, Shaman; Wang, Yang; Yan, Xiufeng

    2014-01-01

    Betulinic acid is a pentacyclic triterpenoid that exhibits anticancer functions in human cancer cells. This study provides evidence that betulinic acid is highly effective against the human cervical cancer cell line HeLa by inducing dose- and time-dependent apoptosis. The apoptotic process was further investigated using a proteomics approach to reveal protein expression changes in HeLa cells following betulinic acid treatment. Proteomic analysis revealed that there were six up- and thirty down-regulated proteins in betulinic acid-induced HeLa cells, and these proteins were then subjected to functional pathway analysis using multiple analysis software. UDP-glucose 6-dehydrogenase, 6-phosphogluconate dehydrogenase decarboxylating, chain A Horf6-a novel human peroxidase enzyme that involved in redox process, was found to be down-regulated during the apoptosis process of the oxidative stress response pathway. Consistent with our results at the protein level, an increase in intracellular reactive oxygen species was observed in betulinic acid-treated cells. The proteins glucose-regulated protein and cargo-selection protein TIP47, which are involved in the endoplasmic reticulum pathway, were up-regulated by betulinic acid treatment. Meanwhile, 14-3-3 family proteins, including 14-3-3β and 14-3-3ε, were down-regulated in response to betulinic acid treatment, which is consistent with the decrease in expression of the target genes 14-3-3β and 14-3-3ε. Furthermore, it was found that the antiapoptotic bcl-2 gene was down-regulated while the proapoptotic bax gene was up-regulated after betulinic acid treatment in HeLa cells. These results suggest that betulinic acid induces apoptosis of HeLa cells by triggering both the endoplasmic reticulum pathway and the ROS-mediated mitochondrial pathway.

  4. Vanillin formation from ferulic acid in Vanilla planifolia is catalysed by a single enzyme

    Science.gov (United States)

    Gallage, Nethaji J.; Hansen, Esben H.; Kannangara, Rubini; Olsen, Carl Erik; Motawia, Mohammed Saddik; Jørgensen, Kirsten; Holme, Inger; Hebelstrup, Kim; Grisoni, Michel; Møller, Birger Lindberg

    2014-01-01

    Vanillin is a popular and valuable flavour compound. It is the key constituent of the natural vanilla flavour obtained from cured vanilla pods. Here we show that a single hydratase/lyase type enzyme designated vanillin synthase (VpVAN) catalyses direct conversion of ferulic acid and its glucoside into vanillin and its glucoside, respectively. The enzyme shows high sequence similarity to cysteine proteinases and is specific to the substitution pattern at the aromatic ring and does not metabolize caffeic acid and p-coumaric acid as demonstrated by coupled transcription/translation assays. VpVAN localizes to the inner part of the vanilla pod and high transcript levels are found in single cells located a few cell layers from the inner epidermis. Transient expression of VpVAN in tobacco and stable expression in barley in combination with the action of endogenous alcohol dehydrogenases and UDP-glucosyltransferases result in vanillyl alcohol glucoside formation from endogenous ferulic acid. A gene encoding an enzyme showing 71% sequence identity to VpVAN was identified in another vanillin-producing plant species Glechoma hederacea and was also shown to be a vanillin synthase as demonstrated by transient expression in tobacco. PMID:24941968

  5. UDP glucuronosyltransferase (UGT) 1A6 pharmacogenetics: I. Identification of polymorphisms in the 5'-regulatory and exon 1 regions, and association with human liver UGT1A6 gene expression and glucuronidation.

    Science.gov (United States)

    Krishnaswamy, Soundararajan; Hao, Qin; Al-Rohaimi, Abdul; Hesse, Leah M; von Moltke, Lisa L; Greenblatt, David J; Court, Michael H

    2005-06-01

    UDP glucuronosyltransferase (UGT) 1A6 is a major isoform in human liver that glucuronidates numerous drugs, toxins, and endogenous substrates with high interindividual variability. The molecular basis for this variability remains unknown, although it likely involves genetic and environmental factors. Phenotype-genotype studies were conducted using a well characterized human liver bank (n = 54) and serotonin glucuronidation as a UGT1A6-specific phenotype marker. A positive moderate-to-heavy alcohol use history (>14 drinks per week) was the only demographic factor examined that correlated with phenotype and was associated with 2-fold higher serotonin glucuronidation (p g, -1310del5, and -652g-->a). Initial univariate analyses did not identify any significant phenotype-genotype associations. However, in livers without substantial alcohol exposure, 50% lower UGT1A6 mRNA levels (p = 0.026) were found in carriers of the linked S7A-enhancer polymorphisms compared with noncarriers but without significant effect on UGT1A6 protein content or glucuronidation activities. Three major haplotypes, including (*)1A (reference), (*)1B (-1535g-->a and -427g-->c), and (*)2 (-1710c-->g, -1310del5, -652g-->a, S7A, T181A, and R184S), were identified, accounting for 90% of alleles. No association of haplotype with any of the phenotype measures could be discerned. In conclusion, although the identified UGT1A6 polymorphisms did not explain the observed glucuronidation variability, there does seem to be a significant role for environmental factors associated with alcohol consumption.

  6. Autoradiographic examinations on the synthesis of the virus herpes simplex in macrophages, rabbit kidney- and BHK-cells by labelling with 3H-thymidine, 3H-uridine and UDP-3H-galactose

    International Nuclear Information System (INIS)

    Lindermann, J.

    1979-01-01

    After injection, an autoradiographically measurable reduplication of virus-specific DNA takes place in NMRI-macrophages infected with HSV (herpes simplex virus). For this process, a sufficient duration of the 3 H-thymidine pulses is of essential importance. An infection with HSV of the Lennette strain induces in considerably more cells of a macrophage population the production of virus-specific DNA than the infection with HSV of the D-316 type. After injection a reduplication of virus-specific DNA occurs in more cells of a HSV-infected population of old macrophages than in that one consisting of young macrophages. In the 7th hour after injection a reduction of RNA synthesis was observed in the HSV-infected macrophage cultures. After HSV-infection, a synthesis of virus-specific DNA could not be detected autoradiographically in macrophages of C 57/bl mice. After HSV-infection the virus-specific DNA synthesis was also observed in activated macrophages of NMRI mice, which had been treated with thioglucollate 72 hours before cell extraction. In general, the previous thioglucollate treatment increased the susceptibility of the macrophages of infection with subsequent reduplication of herpes-specific DNA. Compared to other not infected but activated macrophages, the RNA synthesis after injection was found to be not (HSV Lennette) or only minutely (HSV D-316) reduced in HSV-infected cultures of activated macrophages. In the investigations about the utilisation of exogenic UDP- 3 H-galactose by BHK and rabbit cells it was observed that only few cells of the cultures provide an externally accessible galactosyl transferase activity. Due to the influence of cell-damaging mechanisms a cell proliferation is induced, which is accompanied by externally accessible galactosyl transferase activities in the cell cultures. (orig./MG) [de

  7. Role of UDP-Glucuronosyltransferase (UGT) 2B2 in Metabolism of Triiodothyronine: Effect of Microsomal Enzyme Inducers in Sprague Dawley and UGT2B2-Deficient Fischer 344 Rats

    Science.gov (United States)

    Richardson, Terrilyn A.; Klaassen, Curtis D.

    2010-01-01

    Microsomal enzyme inducers (MEI) that increase UDP-glucuronosyltransferases (UGTs) can impact thyroid hormone homeostasis in rodents. Increased glucuronidation can result in reduction of serum thyroid hormone and a concomitant increase in thyroid-stimulating hormone (TSH). UGT2B2 is thought to glucuronidate triiodothyronine (T3). The purposes of this study were to determine the role of UGT2B2 in T3 glucuronidation and whether increased T3 glucuronidation mediates the increased TSH observed after MEI treatment. Sprague Dawley (SD) and UGT2B2-deficient Fischer 344 (F344) rats were fed a control diet or diet containing pregnenolone-16α-carbonitrile (PCN; 800 ppm), 3-methylcholanthrene (3-MC; 200 ppm), or Aroclor 1254 (PCB; 100 ppm) for 7 days. Serum thyroxine (T4), T3, and TSH concentrations, hepatic androsterone/T4/T3 glucuronidation, and thyroid follicular cell proliferation were determined. In both SD and F344 rats, MEI treatments decreased serum T4, whereas serum T3 was maintained (except with PCB treatment). Hepatic T4 glucuronidation increased significantly after MEI in both rat strains. Compared with the other MEI, only PCN treatment significantly increased T3 glucuronidation (281 and 497%) in both SD and UGT2B2-deficient F344 rats, respectively, and increased both serum TSH and thyroid follicular cell proliferation. These data demonstrate an association among increases in T3 glucuronidation, TSH, and follicular cell proliferation after PCN treatment, suggesting that T3 is glucuronidated by other PCN-inducible UGTs in addition to UGT2B2. These data also suggest that PCN (rather than 3-MC or PCB) promotes thyroid tumors through excessive TSH stimulation of the thyroid gland. PMID:20421340

  8. Effect of ultrasonic degradation of hyaluronic acid extracted from rooster comb on antioxidant and antiglycation activities.

    Science.gov (United States)

    Hafsa, Jawhar; Chaouch, Mohamed Aymen; Charfeddine, Bassem; Rihouey, Christophe; Limem, Khalifa; Le Cerf, Didier; Rouatbi, Sonia; Majdoub, Hatem

    2017-12-01

    Recently, low-molecular-weight hyaluronic acid (LMWHA) has been reported to have novel features, such as free radical scavenging activities, antioxidant activities and dietary supplements. In this study, hyaluronic acid (HA) was extracted from rooster comb and LMWHA was obtained by ultrasonic degradation in order to assess their antioxidant and antiglycation activities. Molecular weight (Mw) and the content of glucuronic acid (GlcA) were used as the index for comparison of the effect of ultrasonic treatment. The effects on the structure were determined by ultraviolet (UV) spectra and Fourier transform infrared spectra (FTIR). The antioxidant activity was determined by three analytical assays (DPPH, NO and TBARS), and the inhibitory effect against glycated-BSA was also assessed. The GlcA content of HA and LMWHA was estimated at about 48.6% and 47.3%, respectively. The results demonstrate that ultrasonic irradiation decreases the Mw (1090-181 kDa) and intrinsic viscosity (1550-473 mL/g), which indicate the cleavage of the glycosidic bonds. The FTIR and UV spectra did not significantly change before and after degradation. The IC 50 value of HA and LWMHA was 1.43, 0.76 and 0.36 mg/mL and 1.20, 0.89 and 0.17 mg/mL toward DPPH, NO and TBARS, respectively. Likewise LMWHA exhibited significant inhibitory effects on the AGEs formation than HA. The results demonstrated that the ultrasonic irradiation did not damage and change the chemical structure of HA after degradation; furthermore, decreasing Mw and viscosity of LMWHA after degradation may enhance the antioxidant and antiglycation activity.

  9. UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE binds to alpha-actinin 1: novel pathways in skeletal muscle?

    Directory of Open Access Journals (Sweden)

    Shira Amsili

    Full Text Available BACKGROUND: Hereditary inclusion body myopathy (HIBM is a rare neuromuscular disorder caused by mutations in GNE, the key enzyme in the biosynthetic pathway of sialic acid. While the mechanism leading from GNE mutations to the HIBM phenotype is not yet understood, we searched for proteins potentially interacting with GNE, which could give some insights about novel putative biological functions of GNE in muscle. METHODOLOGY/PRINCIPAL FINDINGS: We used a Surface Plasmon Resonance (SPR-Biosensor based assay to search for potential GNE interactors in anion exchanged fractions of human skeletal muscle primary culture cell lysate. Analysis of the positive fractions by in vitro binding assay revealed alpha-actinin 1 as a potential interactor of GNE. The direct interaction of the two proteins was assessed in vitro by SPR-Biosensor based kinetics analysis and in a cellular environment by a co-immunoprecipitation assay in GNE overexpressing 293T cells. Furthermore, immunohistochemistry on stretched mouse muscle suggest that both GNE and alpha-actinin 1 localize to an overlapping but not identical region of the myofibrillar apparatus centered on the Z line. CONCLUSIONS/SIGNIFICANCE: The interaction of GNE with alpha-actinin 1 might point to its involvement in alpha-actinin mediated processes. In addition these studies illustrate for the first time the expression of the non-muscle form of alpha-actinin, alpha-actinin 1, in mature skeletal muscle tissue, opening novel avenues for its specific function in the sarcomere. Although no significant difference could be detected in the binding kinetics of alpha-actinin 1 with either wild type or mutant GNE in our SPR biosensor based analysis, further investigation is needed to determine whether and how the interaction of GNE with alpha-actinin 1 in skeletal muscle is relevant to the putative muscle-specific function of alpha-actinin 1, and to the muscle-restricted pathology of HIBM.

  10. Formic acid

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, H; Laing, B

    1921-12-03

    The production of formic acid by the oxidation of methane with a metallic oxide or by the interaction of carbon monoxide and water vapor in the presence of a catalyst, preferably a metallic oxide, is described along with the destructive distillation of carbonaceous material in the preesnce of formic acid vapor for the purpose of increasing the yield of condensible hydrocarbons.

  11. The crucial protective role of glutathione against tienilic acid hepatotoxicity in rats

    International Nuclear Information System (INIS)

    Nishiya, Takayoshi; Mori, Kazuhiko; Hattori, Chiharu; Kai, Kiyonori; Kataoka, Hiroko; Masubuchi, Noriko; Jindo, Toshimasa; Manabe, Sunao

    2008-01-01

    To investigate the hepatotoxic potential of tienilic acid in vivo, we administered a single oral dose of tienilic acid to Sprague-Dawley rats and performed general clinicopathological examinations and hepatic gene expression analysis using Affymetrix microarrays. No change in the serum transaminases was noted at up to 1000 mg/kg, although slight elevation of the serum bile acid and bilirubin, and very mild hepatotoxic changes in morphology were observed. In contrast to the marginal clinicopathological changes, marked upregulation of the genes involved in glutathione biosynthesis [glutathione synthetase and glutamate-cysteine ligase (Gcl)], oxidative stress response [heme oxygenase-1 and NAD(P)H dehydrogenase quinone 1] and phase II drug metabolism (glutathione S-transferase and UDP glycosyltransferase 1A6) were noted after 3 or 6 h post-dosing. The hepatic reduced glutathione level decreased at 3-6 h, and then increased at 24 or 48 h, indicating that the upregulation of NF-E2-related factor 2 (Nrf2)-regulated gene and the late increase in hepatic glutathione are protective responses against the oxidative and/or electrophilic stresses caused by tienilic acid. In a subsequent experiment, tienilic acid in combination with L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of Gcl caused marked elevation of serum alanine aminotransferase (ALT) with extensive centrilobular hepatocyte necrosis, whereas BSO alone showed no hepatotoxicity. The elevation of ALT by this combination was observed at the same dose levels of tienilic acid as the upregulation of the Nrf2-regulated genes by tienilic acid alone. In conclusion, these results suggest that the impairment of glutathione biosynthesis may play a critical role in the development of tienilic acid hepatotoxicity through extensive oxidative and/or electrophilic stresses

  12. Tetranuclear copper(II) complexes bridged by alpha-D-glucose-1-phosphate and incorporation of sugar acids through the Cu4 core structural changes.

    Science.gov (United States)

    Kato, Merii; Sah, Ajay Kumar; Tanase, Tomoaki; Mikuriya, Masahiro

    2006-08-21

    -D-gluconolactone, D-glucuronic acid, or D-glucaric acid in dimethylformamide resulted in the formation of discrete tetracopper complexes with sugar acids, [Cu4{mu-(alpha-D-Glc-1P)}2(mu-SA)2(bpy)4](NO3)2 [SA = D-gluconate (6), D-glucuronate (7), D-glucarateH (8a)]. The structures of 6 and 7 were determined by X-ray crystallography to be almost identical with that of 3 with additional chelating coordination of the C-2 hydroxyl group of D-gluconate moieties (6) or the C-5 cyclic O atom of D-glucuronate units (7). Those with D-glucaric acid and D-lactobionic acid afforded chiral one-dimensional polymers, {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-D-glucarate)(bpy)4](NO3)2}n (8b) and {[Cu4{mu-(alpha-D-Glc-1P)}2(mu-D-lactobionate)(bpy)4(H2O)2](NO3)3}n (9), respectively, in which the D-Glc-1P-bridged tetracopper(II) units are connected by sugar acid moieties through the C-1 and C-6 carboxylate O atoms in 8b and the C-1 carboxylate and C-6 alkoxy O atoms of the gluconate chain in 9. When complex 7 containing d-glucuronate moieties was heated in water, the mononuclear copper(II) complex with 2-dihydroxy malonate, [Cu(mu-O2CC(OH)2CO2)(bpy)] (10), and the dicopper(II) complex with oxalate, [Cu2(mu-C2O4)(bpy)2(H2O)2](NO3)2 (11), were obtained as a result of oxidative degradation of the carbohydrates through C-C bond cleavage reactions.

  13. Cell wall ingrowths in nematode induced syncytia require UGD2 and UGD3.

    Directory of Open Access Journals (Sweden)

    Shahid Siddique

    Full Text Available The cyst nematode Heterodera schachtii infects roots of Arabidopsis plants and establishes feeding sites called syncytia, which are the only nutrient source for nematodes. Development of syncytia is accompanied by changes in cell wall structures including the development of cell wall ingrowths. UDP-glucuronic acid is a precursor of several cell wall polysaccharides and can be produced by UDP-glucose dehydrogenase through oxidation of UDP-glucose. Four genes in Arabidopsis encode this enzyme. Promoter::GUS analysis revealed that UGD2 and UGD3 were expressed in syncytia as early as 1 dpi while expression of UGD1 and UGD4 could only be detected starting at 2 dpi. Infection assays showed no differences between Δugd1 and Δugd4 single mutants and wild type plants concerning numbers of males and females and the size of syncytia and cysts. On single mutants of Δugd2 and Δugd3, however, less and smaller females, and smaller syncytia formed compared to wild type plants. The double mutant ΔΔugd23 had a stronger effect than the single mutants. These data indicate that UGD2 and UGD3 but not UGD1 and UGD4 are important for syncytium development. We therefore studied the ultrastructure of syncytia in the ΔΔugd23 double mutant. Syncytia contained an electron translucent cytoplasm with degenerated cellular organelles and numerous small vacuoles instead of the dense cytoplasm as in syncytia developing in wild type roots. Typical cell wall ingrowths were missing in the ΔΔugd23 double mutant. Therefore we conclude that UGD2 and UGD3 are needed for the production of cell wall ingrowths in syncytia and that their lack leads to a reduced host suitability for H. schachtii resulting in smaller syncytia, lower number of developing nematodes, and smaller females.

  14. An HPLC Method for Microanalysis and Pharmacokinetics of Marine Sulfated Polysaccharide PSS-Loaded Poly Lactic-co-Glycolic Acid (PLGA Nanoparticles in Rat Plasma

    Directory of Open Access Journals (Sweden)

    Hua-Shi Guan

    2013-04-01

    Full Text Available This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD at 250 nm (excitation and 435 nm (emission using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1–500 μg/mL, and the lower limit of detection (LLOD was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA nanoparticles (PSS-NP in rat plasma after a single intravenous (PSS only and oral administration (PSS and PSS-NP. Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.

  15. 5-Acetamido-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid-containing O-polysaccharide from marine bacterium Pseudomonas glareae KMM 9500T.

    Science.gov (United States)

    Kokoulin, Maxim S; Kalinovsky, Anatoly I; Romanenko, Lyudmila A; Mikhailov, Valery V

    2018-05-22

    The O-polysaccharide was isolated from the lipopolysaccharide of a marine bacterium Pseudomonas glareae KMM 9500 T and studied by chemical methods along with 1D and 2D 1 H and 13 C NMR spectroscopy including 1 H, 1 H-TOCSY, 1 H, 1 H-COSY, 1 H, 1 H-ROESY, 1 H, 13 C-HSQC and 1 H, 13 C-HMBC experiments. The O-polysaccharide was found to consist of linear tetrasaccharide repeating units constituted by D-glucuronic acid (D-GlcA), L-rhamnose (L-Rha), D-glucose (D-Glc) and 5-acetamido-7,9-O-[(S)-1-carboxyethylidene]-3,5-dideoxy-L-glycero-L-manno-non-2-ulosonic acid (Sug7,9(S-Pyr)), partially O-acetylated at position 8 (∼70%): →4)-α-D-GlcpA-(1→3)-β-L-Rhap-(1→4)-β-D-Glcp-(1→4)-β-Sugp8Ac(∼70%)7,9(S-Pyr)-(2→. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. In Vitro Inhibition of Human UDP-Glucuronosyl-Transferase (UGT Isoforms by Astaxanthin, β-Cryptoxanthin, Canthaxanthin, Lutein, and Zeaxanthin: Prediction of in Vivo Dietary Supplement-Drug Interactions

    Directory of Open Access Journals (Sweden)

    Yu Fen Zheng

    2016-08-01

    Full Text Available Despite the widespread use of the five major xanthophylls astaxanthin, β-cryptoxanthin, canthaxanthin, lutein, and zeaxanthin as dietary supplements, there have been no studies regarding their inhibitory effects on hepatic UDP-glucuronosyltransferases (UGTs. Here, we evaluated the inhibitory potential of these xanthophylls on the seven major human hepatic UGTs (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7 and UGT2B15 in vitro by LC-MS/MS using specific marker reactions in human liver microsomes (except UGT2B15 or recombinant supersomes (UGT2B15. We also predicted potential dietary supplement-drug interactions for β-cryptoxanthin via UGT1A1 inhibition. We demonstrated that astaxanthin and zeaxanthin showed no apparent inhibition, while the remaining xanthophylls showed only weak inhibitory effects on the seven UGTs. β-Cryptoxanthin mildly inhibited UGT1A1, UGT1A3, and UGT1A4, with IC50 values of 18.8 ± 2.07, 28.3 ± 4.40 and 34.9 ± 5.98 μM, respectively. Canthaxanthin weakly inhibited UGT1A1 and UGT1A3, with IC50 values of 38.5 ± 4.65 and 41.2 ± 3.14 μM, respectively; and lutein inhibited UGT1A1 and UGT1A4, with IC50 values of 45.5 ± 4.01 and 28.7 ± 3.79 μM, respectively. Among the tested xanthophyll-UGT pairs, β-cryptoxanthin showed the strongest competitive inhibition of UGT1A1 (Ki, 12.2 ± 0.985 μM. In addition, we predicted the risk of UGT1A1 inhibition in vivo using the reported maximum plasma concentration after oral administration of β-cryptoxanthin in humans. Our data suggests that these xanthophylls are unlikely to cause dietary supplement-drug interactions mediated by inhibition of the hepatic UGTs. These findings provide useful information for the safe clinical use of the tested xanthophylls.

  17. In Vitro Inhibition of Human UDP-Glucuronosyl-Transferase (UGT) Isoforms by Astaxanthin, β-Cryptoxanthin, Canthaxanthin, Lutein, and Zeaxanthin: Prediction of in Vivo Dietary Supplement-Drug Interactions.

    Science.gov (United States)

    Zheng, Yu Fen; Min, Jee Sun; Kim, Doyun; Park, Jung Bae; Choi, Sung-Wook; Lee, Eun Seong; Na, Kun; Bae, Soo Kyung

    2016-08-12

    Despite the widespread use of the five major xanthophylls astaxanthin, β-cryptoxanthin, canthaxanthin, lutein, and zeaxanthin as dietary supplements, there have been no studies regarding their inhibitory effects on hepatic UDP-glucuronosyltransferases (UGTs). Here, we evaluated the inhibitory potential of these xanthophylls on the seven major human hepatic UGTs (UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7 and UGT2B15) in vitro by LC-MS/MS using specific marker reactions in human liver microsomes (except UGT2B15) or recombinant supersomes (UGT2B15). We also predicted potential dietary supplement-drug interactions for β-cryptoxanthin via UGT1A1 inhibition. We demonstrated that astaxanthin and zeaxanthin showed no apparent inhibition, while the remaining xanthophylls showed only weak inhibitory effects on the seven UGTs. β-Cryptoxanthin mildly inhibited UGT1A1, UGT1A3, and UGT1A4, with IC50 values of 18.8 ± 2.07, 28.3 ± 4.40 and 34.9 ± 5.98 μM, respectively. Canthaxanthin weakly inhibited UGT1A1 and UGT1A3, with IC50 values of 38.5 ± 4.65 and 41.2 ± 3.14 μM, respectively; and lutein inhibited UGT1A1 and UGT1A4, with IC50 values of 45.5 ± 4.01 and 28.7 ± 3.79 μM, respectively. Among the tested xanthophyll-UGT pairs, β-cryptoxanthin showed the strongest competitive inhibition of UGT1A1 (Ki, 12.2 ± 0.985 μM). In addition, we predicted the risk of UGT1A1 inhibition in vivo using the reported maximum plasma concentration after oral administration of β-cryptoxanthin in humans. Our data suggests that these xanthophylls are unlikely to cause dietary supplement-drug interactions mediated by inhibition of the hepatic UGTs. These findings provide useful information for the safe clinical use of the tested xanthophylls.

  18. Chemical Genetic Analysis and Functional Characterization of Staphylococcal Wall Teichoic Acid 2-Epimerases Reveals Unconventional Antibiotic Drug Targets

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Paul A.; Müller, Anna; Wolff, Kerstin A.; Fischmann, Thierry; Wang, Hao; Reed, Patricia; Hou, Yan; Li, Wenjin; Müller, Christa E.; Xiao, Jianying; Murgolo, Nicholas; Sher, Xinwei; Mayhood, Todd; Sheth, Payal R.; Mirza, Asra; Labroli, Marc; Xiao, Li; McCoy, Mark; Gill, Charles J.; Pinho, Mariana G.; Schneider, Tanja; Roemer, Terry (Merck); (Bonn); (FCT/UNL)

    2016-05-04

    Here we describe a chemical biology strategy performed in Staphylococcus aureus and Staphylococcus epidermidis to identify MnaA, a 2-epimerase that we demonstrate interconverts UDP-GlcNAc and UDP-ManNAc to modulate substrate levels of TarO and TarA wall teichoic acid (WTA) biosynthesis enzymes. Genetic inactivation of mnaA results in complete loss of WTA and dramatic in vitro β-lactam hypersensitivity in methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE). Likewise, the β-lactam antibiotic imipenem exhibits restored bactericidal activity against mnaA mutants in vitro and concomitant efficacy against 2-epimerase defective strains in a mouse thigh model of MRSA and MRSE infection. Interestingly, whereas MnaA serves as the sole 2-epimerase required for WTA biosynthesis in S. epidermidis, MnaA and Cap5P provide compensatory WTA functional roles in S. aureus. We also demonstrate that MnaA and other enzymes of WTA biosynthesis are required for biofilm formation in MRSA and MRSE. We further determine the 1.9Å crystal structure of S. aureus MnaA and identify critical residues for enzymatic dimerization, stability, and substrate binding. Finally, the natural product antibiotic tunicamycin is shown to physically bind MnaA and Cap5P and inhibit 2-epimerase activity, demonstrating that it inhibits a previously unanticipated step in WTA biosynthesis. In summary, MnaA serves as a new Staphylococcal antibiotic target with cognate inhibitors predicted to possess dual therapeutic benefit: as combination agents to restore β-lactam efficacy against MRSA and MRSE and as non-bioactive prophylactic agents to prevent Staphylococcal biofilm formation.

  19. Lipoic Acid

    Directory of Open Access Journals (Sweden)

    Ramazan Tetikcok

    2015-09-01

    Full Text Available Lipoic acid, which is defined as a miralce antioxidan, is used by many departments. Eventhough clinical using data are very limited , it is used in treatment of diabetic neuropathy, physical therapy and rehabilitation clinic, dermatology clinic, geriatric clinics. It has usage area for cosmetic purposes. Although there are reports there are the direction of the effectiveness in these areas, the works done are not enough. Today lipoic acid , used in many areas ,is evaluated as universal antioxidant [J Contemp Med 2015; 5(3.000: 206-209

  20. Mefenamic Acid

    Science.gov (United States)

    Mefenamic acid comes as a capsule to take by mouth. It is usually taken with food every 6 hours as needed for up to 1 week. Follow ... pain vomit that is bloody or looks like coffee grounds black, tarry, or bloody stools slowed breathing ...

  1. Acid rain. Les pluies acides

    Energy Technology Data Exchange (ETDEWEB)

    Curren, T

    1979-11-28

    This report was produced for the use of Members of Parliament and House of Commons committees. The document describes the formation of acid rain, emissions of acidifying pollutants in North America, the growth of the problem and its environmental effects on aquatic and terrestrial ecosystems, human health and man-made structures. Areas of Canada which are most susceptible are identified. Actions taken by Parliament are given, including the formation of a sub-committee on acid rain and the passing of Bill C-51 in 1980 to amend the Clean Air Act, bringing it closer to a similar law in the U.S. A chronology of government responses to acid rain at the international, national and provincial level, is given. The most recent government actions included the passing of the US Clean Air Act by the Senate, the amending of the act into law, and commencement of negotiations to develop a Canada-US Air Quality Accord. 10 refs.

  2. Levulinic acid

    Directory of Open Access Journals (Sweden)

    Barbara Hachuła

    2013-09-01

    Full Text Available The title compound (systematic name: 4-oxopentanoic acid, C5H8O3, is close to planar (r.m.s. deviation = 0.0762 Å. In the crystal, the molecules interact via O—H...O hydrogen bonds in which the hydroxy O atoms act as donors and the ketone O atoms in adjacent molecules as acceptors, forming C(7 chains along [20-1].

  3. Solubilization and purification of the glucosyltransferase involved in the biosynthesis of teichuronic acid by fragments of Micrococcus luteus cell membranes

    International Nuclear Information System (INIS)

    Hildebrandt, K.M.; Anderson, J.S.

    1987-01-01

    Enzymes involved in the biosynthesis of teichuronic acid have been demonstrated in cytoplasmic membrane fragments recovered from lysozyme treated Micrococcus luteus cells. Solubilization of the glucosyltransferase activity was effected with aqueous solutions of Triton X-100, Nonidet P-40, Tween 20, or Thesit. Thesit proved most amenable for recovery of glucosyltransferase activity as well as spectrophotometric protein determinations. Recovery of the glucosyltranferase activity was aided during purification by inclusion of 15% glycerol, 0.75% Thesit, 20 mM magnesium ion and 2 mM 2-mercaptoethanol in all buffers. Glucosyltransferase activity was monitored by the transfer of [ 14 C]glucose from UDP-[ 14 C]glucose to an artificial acceptor. Although the natural acceptor is presumed to be an undecaprenyl diphosphate-activated oligosaccharide, alternate acceptors such as isolated cell wall fractions containing teichuronic acid served equally well. Highly purified teichuronic acid devoid of peptidoglycan was the most effective alternate acceptor. The glucosyltransferase was purified by ammonium sulfate precipitation followed by ion exchange chromatography on DEAE-cellulose yielding an overall 200-fold increase in specific activity

  4. The use of acid detergent insoluble nitrogen to predict digestibility of ...

    African Journals Online (AJOL)

    Animal Nutrition and Animal Products Institute, Private Bag. X2, lrene, 1675 ... predict digestibility of rumen undegradable protein (UDP-D) of heat processed ..... of soybean meal and sunflower seeds for dairy cattle in early lactation. J. Dairy ...

  5. Understanding Acid Rain

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  6. The Key Enzyme of the Sialic Acid Metabolism Is Involved in Embryoid Body Formation and Expression of Marker Genes of Germ Layer Formation

    Directory of Open Access Journals (Sweden)

    Annett Thate

    2013-10-01

    Full Text Available The bi-functional enzyme UDP-N-acetyl-2-epimerase/N-acetylmannosamine kinase (GNE is the key enzyme of the sialic acid biosynthesis. Sialic acids are negatively charged nine carbon amino sugars and are found on most glycoproteins and many glycolipids in terminal positions, where they are involved in a variety of biological important molecular interactions. Inactivation of the GNE by homologous recombination results in early embryonic lethality in mice. Here, we report that GNE-deficient embryonic stem cells express less differentiation markers compared to wild-type embryonic stem cells. As a result, GNE-deficient embryonic stem cells fail to form proper embryoid bodies (EB within the first day of culture. However, when culturing these cells in the presence of sialic acids for three days, also GNE-deficient embryonic stem cells form normal EBs. In contrast, when culturing these cells in sialic acid reduced medium, GNE-deficient embryonic stem cells proliferate faster and form larger EBs without any change in the expression of markers of the germ layers.

  7. Characterization and Antiproliferative Effect of Novel Acid Polysaccharides from the Spent Substrate of Shiitake Culinary-Medicinal Mushroom Lentinus edodes (Agaricomycetes) Cultivation.

    Science.gov (United States)

    Zhang, Yong; Liu, Wei; Xu, Chunping; Huang, Wei; He, Peixin

    2017-01-01

    In this study, a high yield of crude polysaccharide (16.73 ± 0.756%) was extracted from the spent mushroom substrate of Lentinus edodes using a hot alkali extraction method. Two groups of polysaccharides (designated as LSMS-1 and LSMS-2) were obtained from the crude extract by size exclusion chromatography (SEC), and their molecular characteristics were examined by a multiangle laser-light scattering (MALLS) and refractive index detector system. The weight-average molar masses of LSMS-1 and LSMS-2 were determined to be 6.842 × 106 and 2.154 × 106 g/mol, respectively. The SEC/MALLS analysis revealed that the molecular shapes of LSMS-1 and LSMS-2 were sphere-like forms in aqueous solution. Carbohydrate composition analysis using chromatography--mass spectrometry revealed that they were both acid heteropolysaccharides. LSMS-1 comprised mainly glucose and galacturonic acid, whereas LSMS-2 mainly consisted of xylose and glucuronic acid. Fourier transform infrared spectral analysis of the purified fractions revealed typical characteristic polysaccharide groups. In addition, MTT assays with refined polysaccharide doses of 25, 50, 100, 200, and 400 µg/mL suggested that both of the polysaccharide fractions exhibited antiproliferative activity against 6 tested human tumor cell lines in a concentration-dependent manner, and LSMS-2 had better anticancer capacity in vitro than LSMS-1. The inhibition ratio of LSMS-2 against A549 human lung cancer cells, the SGC7901 gastric cancer cell line, MCF-7 breast cancer cells, the U937 histiocytic lymphoma cell line, and the MG-63 human osteosarcoma cell line reached 43.55%, 29.97%, 19.63%, 18.24%, and 17.93%, respectively, at a concentration of 400 µg/mL.

  8. Fluorescent molecularly imprinted polymers as plastic antibodies for selective labeling and imaging of hyaluronan and sialic acid on fixed and living cells.

    Science.gov (United States)

    Panagiotopoulou, Maria; Kunath, Stephanie; Medina-Rangel, Paulina Ximena; Haupt, Karsten; Tse Sum Bui, Bernadette

    2017-02-15

    Altered glycosylation levels or distribution of sialic acids (SA) or hyaluronan in animal cells are indicators of pathological conditions like infection or malignancy. We applied fluorescently-labeled molecularly imprinted polymer (MIP) particles for bioimaging of fixed and living human keratinocytes, to localize hyaluronan and sialylation sites. MIPs were prepared with the templates D-glucuronic acid (GlcA), a substructure of hyaluronan, and N-acetylneuraminic acid (NANA), the most common member of SA. Both MIPs were found to be highly selective towards their target monosaccharides, as no cross-reactivity was observed with other sugars like N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, D-glucose and D-galactose, present on the cell surface. The dye rhodamine and two InP/ZnS quantum dots (QDs) emitting in the green and in the red regions were used as fluorescent probes. Rhodamine-MIPGlcA and rhodamine-MIPNANA were synthesized as monodispersed 400nm sized particles and were found to bind selectively their targets located in the extracellular region, as imaged by epifluorescence and confocal microscopy. In contrast, when MIP-GlcA and MIP-NANA particles with a smaller size (125nm) were used, the MIPs being synthesized as thin shells around green and red emitting QDs respectively, it was possible to stain the intracellular and pericellular regions as well. In addition, simultaneous dual-color imaging with the two different colored QDs-MIPs was demonstrated. Importantly, the MIPs were not cytotoxic and did not affect cell viability; neither was the cells morphology affected as demonstrated by live cell imaging. These synthetic receptors could offer a new and promising imaging tool to monitor disease progression. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. The acidic functional groups of humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shanxiang, Li; Shuhe, Sun; Zhai Zongxi, Wu Qihu

    1983-09-01

    The acidic functional groups content, pK value, DELTAH and DELTAS of humic acid (HA) and nitro-humic acid (NHA) were determined by potentiometry, conductometry and calorimetric titration. The thermodynamic parameters of carboxylic groups and phenolic hydroxyl groups of humic acid are similar to that of simple hydroxy-benzoic acid. The configuration sites of acidic functional groups in humic acid from different coals are different. The carbonyl groups on aromatic rings are probably ortho to phenolic -OH for HA and NHA extracted from Huangxian's brown coal and Japanese lignite, while those from Lingshi's weathered coal are not. The weak -COOH groups of the latter possess higher chemical activity. The -COOH content in HA increases, phenolic -OH group decreases and the chemical acidity of acidic functional groups increases when HA is oxidized by nitric acid. (14 refs.)

  10. Okadaic acid

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Severinsen, Mai C K

    2014-01-01

    are the hallmark of phospholipidosis, a pathological condition characterized by lysosomal phospholipid accumulation. Phospholipidosis is observed in acquired lysosomal storage diseases and is induced by a large number of cationic amphiphilic drugs. Unlike the latter, however, OA does not act by accumulating...... in acidic organelles, implying a different toxic mechanism of action. We propose that rapid induction of LBs, an indicator of phospholipidosis, should be included in the future toxicity profile of OA....... hyper protein phosphorylation, but no detectable loss of cell polarity or cytoskeletal integrity of the enterocytes. Using a fluorescent membrane marker, FM dye, endocytosis from the brush border was affected by the toxin. Although constitutive uptake into subapical terminal web-localized early...

  11. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    International Nuclear Information System (INIS)

    Sugumaran, G.; Silbert, J.E.

    1988-01-01

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-[14C]glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo[14C]chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo[14C]chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo[14C] chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo[14C]chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo[14C]chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo[14C]chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo[14C]chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent

  12. Soybean greatly reduces valproic acid plasma concentrations: A food–drug interaction study

    Science.gov (United States)

    Marahatta, Anu; Bhandary, Bidur; Jeong, Seul-Ki; Kim, Hyung-Ryong; Chae, Han-Jung

    2014-01-01

    The aim of this study was to investigate the effects of soy on the pharmacokinetics and pharmacodynamics of valproic acid (VPA). In a preclinical study, rats were pretreated with two different amounts of soy extract for five days (150 mg/kg and 500 mg/kg), which resulted in decreases of 57% and 65% in the Cmax of VPA, respectively. AUC of VPA decreased to 83% and 70% in the soy pretreatment groups. Interestingly, the excretion rate of VPA glucuronide (VPAG) was higher in the soy-fed groups. Levels of UDP-glucuronosyltransferase (UGT) UGT1A3, UGT1A6, UGT2B7 and UGT2B15 were elevated in the soy-treated group, and GABA concentrations were elevated in the brain after VPA administration. However, this was less pronounced in soy extract pretreated group than for the untreated group. This is the first study to report the effects of soy pretreatment on the pharmacokinetics and pharmacodynamics of VPA in rodents. PMID:24618639

  13. Soybean greatly reduces valproic acid plasma concentrations: a food-drug interaction study.

    Science.gov (United States)

    Marahatta, Anu; Bhandary, Bidur; Jeong, Seul-Ki; Kim, Hyung-Ryong; Chae, Han-Jung

    2014-03-12

    The aim of this study was to investigate the effects of soy on the pharmacokinetics and pharmacodynamics of valproic acid (VPA). In a preclinical study, rats were pretreated with two different amounts of soy extract for five days (150 mg/kg and 500 mg/kg), which resulted in decreases of 57% and 65% in the Cmax of VPA, respectively. AUC of VPA decreased to 83% and 70% in the soy pretreatment groups. Interestingly, the excretion rate of VPA glucuronide (VPAG) was higher in the soy-fed groups. Levels of UDP-glucuronosyltransferase (UGT) UGT1A3, UGT1A6, UGT2B7 and UGT2B15 were elevated in the soy-treated group, and GABA concentrations were elevated in the brain after VPA administration. However, this was less pronounced in soy extract pretreated group than for the untreated group. This is the first study to report the effects of soy pretreatment on the pharmacokinetics and pharmacodynamics of VPA in rodents.

  14. Ultrasound-assisted degradation of a new bacterial ...

    African Journals Online (AJOL)

    user

    2012-05-14

    May 14, 2012 ... polysaccharide composed of rhamnose, glucose, mannose, galactose and glucuronic acid in the molar ... distinguish it from thermal or photochemical degradation ..... hydrolysis with dilute acid cleaves the glycosidic bonds in.

  15. Metabolism of skin-absorbed resveratrol into its glucuronized form in mouse skin.

    Directory of Open Access Journals (Sweden)

    Itsuo Murakami

    Full Text Available Resveratrol (RESV is a plant polyphenol, which is thought to have beneficial metabolic effects in laboratory animals as well as in humans. Following oral administration, RESV is immediately catabolized, resulting in low bioavailability. This study compared RESV metabolites and their tissue distribution after oral uptake and skin absorption. Metabolomic analysis of various mouse tissues revealed that RESV can be absorbed and metabolized through skin. We detected sulfated and glucuronidated RESV metabolites, as well as dihydroresveratrol. These metabolites are thought to have lower pharmacological activity than RESV. Similar quantities of most RESV metabolites were observed 4 h after oral or skin administration, except that glucuronidated RESV metabolites were more abundant in skin after topical RESV application than after oral administration. This result is consistent with our finding of glucuronidated RESV metabolites in cultured skin cells. RESV applied to mouse ears significantly suppressed inflammation in the TPA inflammation model. The skin absorption route could be a complementary, potent way to achieve therapeutic effects with RESV.

  16. The Golgi localized bifunctional UDP-rhamnose/UDP-galactose transporter family of Arabidopsis

    DEFF Research Database (Denmark)

    Rautengarten, Carsten; Ebert, Berit; Moreno, Ignacio

    2014-01-01

    Delivery of nucleotide sugar substrates into the Golgi apparatus and endoplasmic reticulum for processes such as cell wall biosynthesis and protein glycosylation is critical for plant growth and development. Plant genomes encode large families of uncharacterized nucleotide sugar transporters that...

  17. Dose-dependent stimulation of hepatic retinoic acid hydroxylation/oxidation and glucuronidation in brook trout, Salvelinus fontinalis, after exposure to 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, P.M.; Ndayibagira, A.; Spear, P.A.

    2000-03-01

    Extremely low stores of vitamin A have been reported in fish and birds inhabiting regions contaminated by coplanar polychlorinated biphenyls (PCBs) and other organochlorines, suggesting many possible effects on retinoid biochemical pathways. Metabolic imbalances associated with biologically active retinoids (e.g., retinoic acid) could be associated with tetratogenesis, edema, growth inhibition, reproductive impairment, immunosuppression, and susceptibility to cancer. Sexually mature brook trout were injected imtraperitoneally with the coplanar PCB 3,3{prime}, 4,4{prime}-tetrachlorobiphenyl (TCBP) and again 4 weeks later. At 8 weeks, retinoic acid metabolism was measured in liver microsomes. To the authors' knowledge, retinoic acid conjugation by UDP-glucuronyltransferase is described here for the first time in fish. A substantial rate of glucuronidation was detected in the microsomes from control brook trout, which tended to increase over the dose range of TCBP. Glucuronidation was significantly greater in fish receiving the 10 {micro}g/g body weight dose level. Metabolism through the cytochrome P450 system was also dose-dependent, resulting in significantly greater production of 4-hydroxyretinoic acid at the 10 {micro}g/g dose level. In contrast, subsequent oxidation to 4-oxo-retinoic acid was greatest at the 1 {micro}g/g dose level and did not increase further at higher doses. Liver stores of dehydroretinyl palmitate/oleate were significantly decreased at the 5 and 10 {micro}g/g dose levels.

  18. Exposure of Atlantic salmon parr (Salmo salar) to a combination of resin acids and a water soluble fraction of diesel fuel oil: A model to investigate the chemical causes of pigmented salmon syndrome

    International Nuclear Information System (INIS)

    Croce, B.; Scottish Environmental Protection Agency, Aberdeen; Stagg, R.M.

    1997-01-01

    Pigmented salmon syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 microg/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 ± 0.1 mg/L (n = 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 microg/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation

  19. [Teichoic acids from lactic acid bacteria].

    Science.gov (United States)

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  20. Optimisation of trans-cinnamic acid and hydrocinnamyl alcohol production with recombinant Saccharomyces cerevisiae and identification of cinnamyl methyl ketone as a by-product.

    Science.gov (United States)

    Gottardi, Manuela; Grün, Peter; Bode, Helge B; Hoffmann, Thomas; Schwab, Wilfried; Oreb, Mislav; Boles, Eckhard

    2017-12-01

    Trans-cinnamic acid (tCA) and hydrocinnamyl alcohol (HcinOH) are valuable aromatic compounds with applications in the flavour, fragrance and cosmetic industry. They can be produced with recombinant yeasts from sugars via phenylalanine after expression of a phenylalanine ammonia lyase (PAL) and an aryl carboxylic acid reductase. Here, we show that in Saccharomyces cerevisiae a PAL enzyme from the bacterium Photorhabdus luminescens was superior to a previously used plant PAL enzyme for the production of tCA. Moreover, after expression of a UDP-glucose:cinnamate glucosyltransferase (FaGT2) from Fragaria x ananassa, tCA could be converted to cinnamoyl-D-glucose which is expected to be less toxic to the yeast cells. Production of tCA and HcinOH from glucose could be increased by eliminating feedback-regulated steps of aromatic amino acid biosynthesis and diminishing the decarboxylation step of the competing Ehrlich pathway. Finally, an unknown by-product resulting from further metabolisation of a carboligation product of cinnamaldehyde (cinALD) with activated acetaldehyde, mediated by pyruvate decarboxylases, could be identified as cinnamyl methyl ketone providing a new route for the biosynthesis of precursors, such as (2S,3R) 5-phenylpent-4-ene-2,3-diol, necessary for the chemical synthesis of specific biologically active drugs such as daunomycin. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Plasma amino acids

    Science.gov (United States)

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  2. Uric acid - urine

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003616.htm Uric acid urine test To use the sharing features on ... are no risks with this test. Images Uric acid test Uric acid crystals References Burns CM, Wortmann RL. Clinical ...

  3. Uric acid test (image)

    Science.gov (United States)

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... for testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  4. Methylmalonic acid blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid in the ...

  5. Facts about Folic Acid

    Science.gov (United States)

    ... Information For… Media Policy Makers Facts About Folic Acid Language: English (US) Español (Spanish) Recommend on Facebook ... of the baby’s brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  6. Optimizing peracetic acid pretreatment conditions for improved simultaneous saccharification and co-fermentation (SSCF) of sugar cane bagasse to ethanol fuel

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Lincoln C. [Fundacao Centro Tecnologico de Minas Gerais, Setor de Biotecnologia e Tecnologia Quimica, Minas Geraid (Brazil); Linden, James C.; Schroeder, Herbert A. [Colorado State Univ., Dept. of Chemical and Bioresource Engineering, Fort Collins, CO (United States)

    1999-01-01

    The use of several lignocellulosic materials for ethanol fuel production has been studied exhaustively in the U.S.A. Strong environmental legislation has been driving efforts by enterprise, state agencies, and universities to make ethanol from biomass economically viable. Production costs for ethanol from biomass have been decreasing year by year as a consequence of this massive effort. Pretreatment, enzyme recovery, and development of efficient microorganisms are some promising areas of study for reducing process costs. Sugar cane bagasse constitutes the most important lignocellulosic material to be considered in Brazil as new technology such as the production of ethanol fuel. At present, most bagasse is burned, and because of its moisture content, has a low value fuel. Ethanol production would result in a value-added product. The bagasse is available at the sugar mill site at no additional cost because harvesting, transportation and storage costs are borne by the sugar production. The present paper presents an alternative pretreatment with low energy input where biomass is treated in a silo type system without need for expensive capitalisation. Experimentally, ground sugar cane bagasse is placed in plastic bags and a peracetic acid solution is added to the biomass at concetrations of 0, 6, 9, 15, 21, 30 and 60% w/w of peracetic acid based on over dried biomass. The ratio of solution to wood is 6:1; a seven day storage period had been used. Tests using hydrolysing enzymes as an indicator for SSCF have been performed to evaluated the pretreatment efficiency. As an auxiliary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetate content in the sugar cane bagasse have been performed before addition of peracetic acid. The alkaline solutions are added to the raw bagasse in a ratio of 17:1 solution to biomass and mixed for 24 hours at room temperature. Biomass is filled

  7. Acid distribution in phosphoric acid fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Okae, I.; Seya, A.; Umemoto, M. [Fuji Electric Co., Ltd., Chiba (Japan)

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  8. Functions of some capsular polysaccharide biosynthetic genes in Klebsiella pneumoniae NTUH K-2044.

    Directory of Open Access Journals (Sweden)

    Jin-Yuan Ho

    Full Text Available The growing number of Klebsiella pneumoniae infections, commonly acquired in hospitals, has drawn great concern. It has been shown that the K1 and K2 capsular serotypes are the most detrimental strains, particularly to those with diabetes. The K1 cps (capsular polysaccharide locus in the NTUH-2044 strain of the pyogenic liver abscess (PLA K. pneumoniae has been identified recently, but little is known about the functions of the genes therein. Here we report characterization of a group of cps genes and their roles in the pathogenesis of K1 K. pneumoniae. By sequential gene deletion, the cps gene cluster was first re-delimited between genes galF and ugd, which serve as up- and down-stream ends, respectively. Eight gene products were characterized in vitro and in vivo to be involved in the syntheses of UDP-glucose, UDP-glucuronic acid and GDP-fucose building units. Twelve genes were identified as virulence factors based on the observation that their deletion mutants became avirulent or lost K1 antigenicity. Furthermore, deletion of kp3706, kp3709 or kp3712 (ΔwcaI, ΔwcaG or Δatf, respectively, which are all involved in fucose biosynthesis, led to a broad range of transcriptional suppression for 52 upstream genes. The genes suppressed include those coding for unknown regulatory membrane proteins and six multidrug efflux system proteins, as well as proteins required for the K1 CPS biosynthesis. In support of the suppression of multidrug efflux genes, we showed that these three mutants became more sensitive to antibiotics. Taken together, the results suggest that kp3706, kp3709 or kp3712 genes are strongly related to the pathogenesis of K. pneumoniae K1.

  9. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes

    International Nuclear Information System (INIS)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-01-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1α (HNF1α) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis

  10. Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

    Science.gov (United States)

    Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

    2003-09-01

    The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

  11. Citric acid urine test

    Science.gov (United States)

    Urine - citric acid test; Renal tubular acidosis - citric acid test; Kidney stones - citric acid test; Urolithiasis - citric acid test ... No special preparation is necessary for this test. But the results ... test is usually done while you are on a normal diet. Ask your ...

  12. Urinary Elimination of Bile Acid Glucuronides under Severe Cholestatic Situations: Contribution of Hepatic and Renal Glucuronidation Reactions

    Directory of Open Access Journals (Sweden)

    Martin Perreault

    2018-01-01

    Full Text Available Biliary obstruction, a severe cholestatic complication, causes accumulation of toxic bile acids (BAs in liver cells. Glucuronidation, catalyzed by UDP-glucuronosyltransferase (UGT enzymes, detoxifies cholestatic BAs. Using liquid chromatography coupled to tandem mass spectrometry, 11 BA glucuronide (-G species were quantified in prebiliary and postbiliary stenting serum and urine samples from 17 patients with biliary obstruction. Stenting caused glucuronide- and fluid-specific changes in BA-G levels and BA-G/BA metabolic ratios. In vitro glucuronidation assays with human liver and kidney microsomes revealed that even if renal enzymes generally displayed lower KM values, the two tissues shared similar glucuronidation capacities for BAs. By contrast, major differences between the two tissues were observed when four human BA-conjugating UGTs 1A3, 1A4, 2B4, and 2B7 were analyzed for mRNA and protein levels. Notably, the BA-24G producing UGT1A3 enzyme, abundant in the liver, was not detected in kidney microsomes. In conclusion, the circulating and urinary BA-G profiles are hugely impacted under severe cholestasis. The similar BA-glucuronidating abilities of hepatic and renal extracts suggest that both the liver and kidney may contribute to the urine BA-G pool.

  13. Enzymes and Inhibitors in Neonicotinoid Insecticide Metabolism

    Science.gov (United States)

    Shi, Xueyan; Dick, Ryan A.; Ford, Kevin A.; Casida, John E.

    2009-01-01

    Neonicotinoid insecticide metabolism involves considerable substrate specificity and regioselectivity of the relevant CYP450, aldehyde oxidase, and phase II enzymes. Human CYP450 recombinant enzymes carry out the following conversions: CYP3A4, 2C19 and 2B6 for thiamethoxam (TMX) to clothianidin (CLO); 3A4, 2C19 and 2A6 for CLO to desmethyl-CLO; 2C19 for TMX to desmethyl-TMX. Human liver aldehyde oxidase reduces the nitro substituent of CLO to nitroso much more rapidly than that of TMX. Imidacloprid (IMI), CLO and several of their metabolites do not give detectable N-glucuronides but 5-hydroxy-IMI, 4,5-diol-IMI and 4-hydroxy-thiacloprid are converted to O-glucuronides in vitro with mouse liver microsomes and UDP-glucuronic acid or in vivo in mice. Mouse liver cytosol with S-adenosylmethionine converts desmethyl-CLO to CLO but not desmethyl-TMX to TMX. Two organophosphorus CYP450 inhibitors partially block IMI, thiacloprid and CLO metabolism in vivo in mice, elevating the brain and liver levels of the parent compounds while reducing amounts of the hydroxylated metabolites. PMID:19391582

  14. Synthesis of a radioiodinated antiestrogen glucuronide compound (TAM-G)

    International Nuclear Information System (INIS)

    Fazilet Zumrut Biber Muftuler; Perihan Unak; Cigdem Ichedef; Ilknur Demir

    2011-01-01

    Tamoxifen [TAM; ([Z]-2-[4-(1,2-diphenyl-1-di-butenyl)-phenoxy]-N,N-dimethylethanamine) has been used as an antiestrogen drug for treatment and prevention of human breast cancer. The aim of this study is conjugation of hydrophilic glucuronic acid to the starting substance TAM and labeling with 131 I using iodogen as oxidizing agent. The reactions are completed in three steps, including enzymatic reaction, with the following sub-steps; preparation of microsomal fraction from rat liver and subsequent purification of UDP-glucuronyl transferase (UDPGT), estimation of protein amount in microsomal samples and glucuronidation reaction. Synthesized glucuronide derivative (TAM-G) was purified using high performance liquid chromatography (HPLC). Mass spectroscopy of cold standard showed that the labeling most probably occurs in ortho position to the aromatic ring containing the ether group of TAM-G as expected. Radiochemical yield of the 131 I labeled TAM-G ([ 131 I]TAM-G) is determined by using Thin Layer Radio Chromatography (TLRC). The radiopharmaceutical potential of [ 131 I]TAM-G is examined by biodistribution studies that is run on normal female Albino Wistar rats. According to biodistribution results 131 I labeled TAM-G may be proposed as a new antiestrogen glucuronide imaging agent for breast and uterus. Electronic supplementary material. The online version of this article (doi:10.1007/s10967-010-0932-7) contains supplementary material, which is available to authorized users. (author)

  15. Acid Deposition Phenomena

    International Nuclear Information System (INIS)

    Ramadan, A.E.K.

    2004-01-01

    Acid deposition, commonly known as acid rain, occurs when emissions from the combustion of fossil fuels and other industrial processes undergo complex chemical reactions in the atmosphere and fall to the earth as wet deposition (rain, snow, cloud, fog) or dry deposition (dry particles, gas). Rain and snow are already naturally acidic, but are only considered problematic when less than a ph of 5.0 The main chemical precursors leading to acidic conditions are atmospheric concentrations of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ). When these two compounds react with water, oxygen, and sunlight in the atmosphere, the result is sulfuric (H 2 SO 4 ) and nitric acids (HNO 3 ), the primary agents of acid deposition which mainly produced from the combustion of fossil fuel and from petroleum refinery. Airborne chemicals can travel long distances from their sources and can therefore affect ecosystems over broad regional scales and in locations far from the sources of emissions. According to the concern of petroleum ministry with the environment and occupational health, in this paper we will discussed the acid deposition phenomena through the following: Types of acidic deposition and its components in the atmosphere Natural and man-made sources of compounds causing the acidic deposition. Chemical reactions causing the acidic deposition phenomenon in the atmosphere. Factors affecting level of acidic deposition in the atmosphere. Impact of acid deposition. Procedures for acidic deposition control in petroleum industry

  16. New high-performance liquid chromatography assay for glycosyltransferases based on derivatization with anthranilic acid and fluorescence detection.

    Science.gov (United States)

    Anumula, Kalyan Rao

    2012-07-01

    Assays were developed using the unique labeling chemistry of 2-aminobenzoic acid (2AA; anthranilic acid, AA) for measuring activities of both β1-4 galactosyltransferase (GalT-1) and α2-6 sialyltransferase (ST-6) by high-performance liquid chromatography (HPLC) with fluorescence detection (Anumula KR. 2006. Advances in fluorescence derivatization methods for high-performance liquid chromatographic analysis of glycoprotein carbohydrates. Anal Biochem. 350:1-23). N-Acetylglucosamine (GlcNAc) and N-acetyllactosamine were used as acceptors and uridine diphosphate (UDP)-galactose and cytidine monophosphate (CMP)-N-acetylneuraminic acid (NANA) as donors for GalT-1 and ST-6, respectively. Enzymatic products were labeled in situ with AA and were separated from the substrates on TSKgel Amide 80 column using normal-phase conditions. Enzyme units were determined from the peak areas by comparison with the concomitantly derivatized standards Gal-β1-4GlcNAc and NANA-α2-6 Gal-β1-4GlcNAc. Linearity (time and enzyme concentration), precision (intra- and interassay) and reproducibility for the assays were established. The assays were found to be useful in monitoring the enzyme activities during isolation and purification. The assays were highly sensitive and performed equal to or better than the traditional radioactive sugar-based measurements. The assay format can also be used for measuring the activity of other transferases, provided that the carbohydrate acceptors contain a reducing end for labeling. An assay for glycoprotein acceptors was developed using IgG. A short HPLC profiling method was developed for the separation of IgG glycans (biantennary G0, G1, G2, mono- and disialylated), which facilitated the determination of GalT-1 and ST-6 activities in a rapid manner. Furthermore, this profiling method should prove useful for monitoring the changes in IgG glycans in clinical settings.

  17. Acid Lipase Disease

    Science.gov (United States)

    ... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ... of Neurological Disorders and Stroke conducts and supports research to understand lipid storage diseases such as acid lipase deficiency and ...

  18. Lactic acid test

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003507.htm Lactic acid test To use the sharing features on this page, please enable JavaScript. Lactic acid is mainly produced in muscle cells and red ...

  19. Amino Acid Metabolism Disorders

    Science.gov (United States)

    ... this process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple syrup urine disease. Amino acids are "building blocks" that join together to form ...

  20. Folic Acid and Pregnancy

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Folic Acid and Pregnancy KidsHealth / For Parents / Folic Acid and Pregnancy Print ...

  1. Omega-6 Fatty Acids

    Science.gov (United States)

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  2. Hydrochloric acid poisoning

    Science.gov (United States)

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  3. Aminolevulinic Acid Topical

    Science.gov (United States)

    Aminolevulinic acid is used in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty ... skin cancer) of the face or scalp. Aminolevulinic acid is in a class of medications called photosensitizing ...

  4. Zoledronic Acid Injection

    Science.gov (United States)

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  5. Azelaic Acid Topical

    Science.gov (United States)

    Azelaic acid gel and foam is used to clear the bumps, lesions, and swelling caused by rosacea (a skin ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat the pimples and ...

  6. Aminocaproic Acid Injection

    Science.gov (United States)

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  7. Deoxycholic Acid Injection

    Science.gov (United States)

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  8. Amino acids and proteins

    NARCIS (Netherlands)

    van Goudoever, Johannes B.; Vlaardingerbroek, Hester; van den Akker, Chris H.; de Groof, Femke; van der Schoor, Sophie R. D.

    2014-01-01

    Amino acids and protein are key factors for growth. The neonatal period requires the highest intake in life to meet the demands. Those demands include amino acids for growth, but proteins and amino acids also function as signalling molecules and function as neurotransmitters. Often the nutritional

  9. Acid Rain Study Guide.

    Science.gov (United States)

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  10. Immunoglobulin and fatty acids

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising 0.1-10 w/w % immunoglobulin (Ig), 4-14 w/w % saturated fatty acids, 4-14 w/w % mono-unsaturated fatty acids and 0-5 w/w % poly-unsaturated fatty acids, wherein the weight percentages are based on the content of dry matter in the composition...

  11. The Acid Rain Reader.

    Science.gov (United States)

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  12. Stomach acid test

    Science.gov (United States)

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour (mEq/ ...

  13. Acidic Ionic Liquids.

    Science.gov (United States)

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  14. Introducing the "TCDD-inducible AhR-Nrf2 gene battery".

    Science.gov (United States)

    Yeager, Ronnie L; Reisman, Scott A; Aleksunes, Lauren M; Klaassen, Curtis D

    2009-10-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) induces genes via the transcription factor aryl hydrocarbon receptor (AhR), including Cyp1a1, NAD(P)H:quinone oxidoreductase 1 (Nqo1), UDP-glucuronosyltransferase 1a6 (Ugt1a6), and glutathione S-transferase a1 (Gsta1). These genes are referred to as the "AhR gene battery." However, Nqo1 is also considered a prototypical target gene of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2). In mice, TCDD induction of Nrf2 and Nrf2 target, Nqo1, is dependent on AhR, and thus TCDD induction of drug-processing genes may be routed through an AhR-Nrf2 sequence. There has been speculation that Nrf2 may be involved in the TCDD induction of drug-processing genes; however, the data are not definitive. Therefore, to address whether TCDD induction of Nqo1, Ugts, and Gsts is dependent on Nrf2, we conducted the definitive experiment by administering TCDD (50 mug/kg, ip) to Nrf2-null and wild-type (WT) mice and collecting livers 24 h later to quantify the mRNA of drug-processing genes. TCDD induction of Cyp1a1 and Ugt1a1 was similar in WT and Nrf2-null mice, whereas TCDD induction of Ugt1a5 and 1a9 was blunted in Nrf2-null mice. TCDD induced Nqo1, Ugt1a6, 2b34, 2b35, 2b36, UDP-glucuronic acid-synthesizing gene UDP-glucose dehydrogenase, and Gsta1, m1, m2, m3, m6, p2, t2, and microsomal Gst1 in WT mice but not in Nrf2-null mice. Therefore, the present study demonstrates the novel finding that Nrf2 is required for TCDD induction of classical AhR battery genes Nqo1, Ugt1a6, and Gsta1, as well as most Ugt and Gst isoforms in livers of mice.

  15. Process for the preparation of lactic acid and glyceric acid

    Science.gov (United States)

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  16. Amino acids in the sedimentary humic and fulvic acids

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.

    acids in the coastal Arabian Sea sediments: whereas amino acids content of fulvic acids was lower than that of humic acids in the coastal sediments of Bay of Bengal. Slope sedimentary humic acids were relatively enriched in amino acids as compared...

  17. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Science.gov (United States)

    2013-04-03

    ..., Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of castor oil, polymer with adipic acid, linoleic acid... pesticide formulation. Advance Polymer Technology submitted a petition to EPA under the Federal Food, Drug...

  18. Bile acid sequestrants

    DEFF Research Database (Denmark)

    Hansen, Morten; Sonne, David P; Knop, Filip K

    2014-01-01

    Bile acids are synthesized in the liver from cholesterol and have traditionally been recognized for their role in absorption of lipids and in cholesterol homeostasis. In recent years, however, bile acids have emerged as metabolic signaling molecules that are involved in the regulation of lipid...... and glucose metabolism, and possibly energy homeostasis, through activation of the bile acid receptors farnesoid X receptor (FXR) and TGR5. Bile acid sequestrants (BASs) constitute a class of drugs that bind bile acids in the intestine to form a nonabsorbable complex resulting in interruption...... of the enterohepatic circulation. This increases bile acid synthesis and consequently reduces serum low-density lipoprotein cholesterol. Also, BASs improve glycemic control in patients with type 2 diabetes. Despite a growing understanding of the impact of BASs on glucose metabolism, the mechanisms behind their glucose...

  19. Citric Acid Alternative to Nitric Acid Passivation

    Science.gov (United States)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  20. USGS Tracks Acid Rain

    Science.gov (United States)

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  1. Acidity of hydroxamic acids and amides

    Czech Academy of Sciences Publication Activity Database

    Böhm, S.; Exner, Otto

    2003-01-01

    Roč. 1, č. 7 (2003), s. 1176-1180 ISSN 1477-0520 R&D Projects: GA AV ČR IAA4072005 Institutional research plan: CEZ:AV0Z4055905 Keywords : hydroxamic acids * DFT calculations * isodesmic reactions Subject RIV: CC - Organic Chemistry

  2. Fusidic acid in dermatology

    DEFF Research Database (Denmark)

    Schöfer, Helmut; Simonsen, Lene

    1995-01-01

    Studies on the clinical efficacy of fusidic acid in skin and soft-tissue infections (SSTIs), notably those due to Staphylococcus aureus, are reviewed. Oral fusidic acid (tablets dosed at 250 mg twice daily, or a suspension for paediatric use at 20 mg/kg/day given as two daily doses) has shown goo...

  3. Characterization of acid tars

    International Nuclear Information System (INIS)

    Leonard, Sunday A.; Stegemann, Julia A.; Roy, Amitava

    2010-01-01

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  4. Characterization of acid tars

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, Sunday A., E-mail: sunday.leonard@ucl.ac.uk [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Stegemann, Julia A. [Department of Civil Environmental and Geomatic Engineering, University College London, Chadwick Building, Gower Street, London, WC1E 6BT (United Kingdom); Roy, Amitava [J. Bennett Johnston, Sr., Centre for Advance Microstructures and Devices (CAMD), 6980 Jefferson Highway, Louisiana State University, Baton Rouge, LA, 70806 (United States)

    2010-03-15

    Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain.

  5. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2003-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  6. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  7. Peptide Nucleic Acids (PNA)

    DEFF Research Database (Denmark)

    2002-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  8. Peptide Nucleic Acids

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds known as peptide nucleic acids, bind complementary DNA and RNA strands, and generally do so more strongly than the corresponding DNA or RNA strands while exhibiting increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from...

  9. Folic acid in diet

    Science.gov (United States)

    ... regularly removed from the body through urine, so excess amounts do not build up in the body. You should not get more than 1000 mcg per day of folic acid. Using higher levels of folic acid can mask vitamin B12 deficiency.

  10. Peptide Nucleic Acid Synthons

    DEFF Research Database (Denmark)

    2004-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary ssDNA and RNA strands more strongly than a corresponding DNA. The peptide nucleic acids generally comprise ligands such as naturally occurring DNA bases attached to a peptide backbone through a suitable linker....

  11. Locked nucleic acid

    DEFF Research Database (Denmark)

    Jepsen, Jan Stenvang; Sørensen, Mads D; Wengel, Jesper

    2004-01-01

    Locked nucleic acid (LNA) is a class of nucleic acid analogs possessing very high affinity and excellent specificity toward complementary DNA and RNA, and LNA oligonucleotides have been applied as antisense molecules both in vitro and in vivo. In this review, we briefly describe the basic...

  12. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Wesén, Clas; Sundin, Peter

    1997-01-01

    Chlorinated fatty acids have been found to be major contributors to organohalogen compounds in fish, bivalves, jellyfish, and lobster, and they have been indicated to contribute considerably to organohalogens in marine mammals. Brominated fatty acids have been found in marine sponges. Also...

  13. Amino Acid Crossword Puzzle

    Science.gov (United States)

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  14. Phosphates and phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Becker, P [Compagnie Francaise de l' Azote, Paris (France)

    1983-01-01

    In chapter 8.5 the following aspects of uranium recovery are treated: basis of extraction process, extraction principle, solvents, strength of the acid to be treated, technology, main processes in use, impact of uranium recovery on phosphoric acid plants, and economics of uranium recovery plants.

  15. Omega-3 Fatty Acids

    Science.gov (United States)

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat- ... in people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  16. Chlorogenic acid and caffeic acid are absorbed in humans

    NARCIS (Netherlands)

    Olthof, Margreet R.; Hollman, Peter C H; Katan, Martijn B.

    2001-01-01

    Chlorogenic acid, an ester of caffeic acid and quinic acid, is a major phenolic compound in coffee; daily intake in coffee drinkers is 0.5-1 g. Chlorogenic acid and caffeic acid are antioxidants in vitro and might therefore contribute to the prevention of cardiovascular disease. However, data on the

  17. Enzymatic formation of hexadecenoic acid from palmitic acid

    International Nuclear Information System (INIS)

    Nakano, Masao; Fujino, Yasuhiko

    1975-01-01

    Desaturation of palmitic acid was investigated in an enzyme system prepared from rat liver. 2-trans-Hexadecenoic acid as well as 9-cis-gexadecenoic acid (palmitoleic acid) were found to be formed as monoenoic acid in this system. (author)

  18. Lewis Acidic Ionic Liquids.

    Science.gov (United States)

    Brown, Lucy C; Hogg, James M; Swadźba-Kwaśny, Małgorzata

    2017-08-21

    Until very recently, the term Lewis acidic ionic liquids (ILs) was nearly synonymous with halometallate ILs, with a strong focus on chloroaluminate(III) systems. The first part of this review covers the historical context in which these were developed, speciation of a range of halometallate ionic liquids, attempts to quantify their Lewis acidity, and selected recent applications: in industrial alkylation processes, in supported systems (SILPs/SCILLs) and in inorganic synthesis. In the last decade, interesting alternatives to halometallate ILs have emerged, which can be divided into two sub-sections: (1) liquid coordination complexes (LCCs), still based on halometallate species, but less expensive and more diverse than halometallate ionic liquids, and (2) ILs with main-group Lewis acidic cations. The two following sections cover these new liquid Lewis acids, also highlighting speciation studies, Lewis acidity measurements, and applications.

  19. Acidity in rainfall

    International Nuclear Information System (INIS)

    Tisue, G.T.; Kacoyannakis, J.

    1975-01-01

    The reported increasing acidity of rainfall raises many interesting ecological and chemical questions. In spite of extensive studies in Europe and North America there are, for example, great uncertainties in the relative contributions of strong and weak acids to the acid-base properties of rainwater. Unravelling this and similar problems may require even more rigorous sample collection and analytical procedures than previously employed. Careful analysis of titration curves permits inferences to be made regarding chemical composition, the possible response of rainwater to further inputs of acidic components to the atmosphere, and the behavior to be expected when rainwater interacts with the buffers present in biological materials and natural waters. Rainwater samples collected during several precipitation events at Argonne National Laboratory during October and November 1975 have been analyzed for pH, acid and base neutralizing properties, and the ions of ammonium, nitrate, chloride, sulfate, and calcium. The results are tabulated

  20. Conjugated Fatty Acid Synthesis

    Science.gov (United States)

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  1. Differential gene expression in tomato fruit and Colletotrichum gloeosporioides during colonization of the RNAi-SlPH tomato line with reduced fruit acidity and higher pH.

    Science.gov (United States)

    Barad, Shiri; Sela, Noa; Dubey, Amit K; Kumar, Dilip; Luria, Neta; Ment, Dana; Cohen, Shahar; Schaffer, Arthur A; Prusky, Dov

    2017-08-04

    The destructive phytopathogen Colletotrichum gloeosporioides causes anthracnose disease in fruit. During host colonization, it secretes ammonia, which modulates environmental pH and regulates gene expression, contributing to pathogenicity. However, the effect of host pH environment on pathogen colonization has never been evaluated. Development of an isogenic tomato line with reduced expression of the gene for acidity, SlPH (Solyc10g074790.1.1), enabled this analysis. Total RNA from C. gloeosporioides colonizing wild-type (WT) and RNAi-SlPH tomato lines was sequenced and gene-expression patterns were compared. C. gloeosporioides inoculation of the RNAi-SlPH line with pH 5.96 compared to the WT line with pH 4.2 showed 30% higher colonization and reduced ammonia accumulation. Large-scale comparative transcriptome analysis of the colonized RNAi-SlPH and WT lines revealed their different mechanisms of colonization-pattern activation: whereas the WT tomato upregulated 13-LOX (lipoxygenase), jasmonic acid and glutamate biosynthesis pathways, it downregulated processes related to chlorogenic acid biosynthesis II, phenylpropanoid biosynthesis and hydroxycinnamic acid tyramine amide biosynthesis; the RNAi-SlPH line upregulated UDP-D-galacturonate biosynthesis I and free phenylpropanoid acid biosynthesis, but mainly downregulated pathways related to sugar metabolism, such as the glyoxylate cycle and L-arabinose degradation II. Comparison of C. gloeosporioides gene expression during colonization of the WT and RNAi-SlPH lines showed that the fungus upregulates ammonia and nitrogen transport and the gamma-aminobutyric acid metabolic process during colonization of the WT, while on the RNAi-SlPH tomato, it mainly upregulates the nitrate metabolic process. Modulation of tomato acidity and pH had significant phenotypic effects on C. gloeosporioides development. The fungus showed increased colonization on the neutral RNAi-SlPH fruit, and limited colonization on the WT acidic fruit

  2. Glycosyltransferase glycosylating flavokermesic acid and/or kermesic acid

    DEFF Research Database (Denmark)

    2016-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I) : conjugating glucose to flavokermesic acid (FK); and/or (II) : conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  3. GLYCOSYLTRANSFERASE GLYCOSYLATING FLAVOKERMESIC ACID AND/OR KERMESIC ACID

    DEFF Research Database (Denmark)

    2015-01-01

    An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid.......An isolated glycosyltransferase (GT) polypeptide capable of: (I): conjugating glucose to flavokermesic acid (FK); and/or (II): conjugating glucose to kermesic acid (KA) and use of this GT to e.g. make Carminic acid....

  4. Waht is 'molybdic acid' or 'polymolybdic acid'?

    International Nuclear Information System (INIS)

    Tytko, K.H.; Baethe, G.; Mehmke, K.

    1987-01-01

    According to a comparative study of the literature, supplemented by well-aimed experimental investigations and equilibrium calculations, the terms 'molybdic acid' or 'polymolybdic acid', used for many substances, species, or solutions in the literature, are applicable to a species, a solution, and two solids: a) The monomeric molybdic acid, most probably having the formula MoO 2 (OH) 2 (H 2 O) 2 (= H 2 MoO 4 , aq), exists in (aqueous) solution only and never exceeds a concentration of ∼ 10 -3 M since at higher concentrations it reacts with other monomeric molybdenum(VI) species to give anionic or cationic polymers. b) A concentrated (> 0.1 M Mo VI ) aqueous molybdate solution of degree of acidification P = 2 (realized, e.g., by a solution of one of the Mo VI oxides; by any molybdate solutions whose cations have been exchanged by H 2 O + on a cation exchanger; by suitable acidification of a molybdate solution) contains 8 H 3 O + and the well-known polyanion Mo 36 O 112 (H 2 O) 16 8- exactly in the stoichiometric proportions. c) A glassy substance, obtained from an alkali metal salt-free solution prepared acording to (b), refers to the compound (H 3 O) 8 [Mo 36 O 112 (H 2 O) 16 ] · xH 2 O, x = 25 - 29. d) A solid having the ideal composition [(H 3 O)Mo 5 O 15 (OH)H 2 O · H 2 O] ∞ consists of a polymolybdate skeleton (the well-known 'decamolybdate' structure), in the tunnels of which H 3 O + and H 2 O are intercalated. The structure is very unstable if only H 3 O + cations are present, but it is enormously stabilized by a partial exchange of H 3 O + by certain alkali or alkaline earth metal cations. For the compounds MoO 3 , MoO 3 ·H 2 O, and MoO 3 · 2 H 2 O the term 'molybdic acid' is unjustified. The commercial product 'molybdic acid, ∼ 85% MoO 3 ' is the well-known polymolybdate (NH 4 ) 2 O · 4 MoO 3 with a layer structure of the polyanion. 84 refs. (author)

  5. Amino acid racemisation dating

    International Nuclear Information System (INIS)

    Murray-Wallace, C.V.

    1999-01-01

    The potential of the time-dependent amino acid racemisation reaction as a method of age assessment was first reported by Hare and Abelson (1968). They noted that in specimens of the bivalve mollusc Mercenaria sp., greater concentrations of amino acids in the D-configuration with increasing fossil age. Hare and Abelson (1968) also reported negligible racemisation in a modern specimen of Mecanaria sp. On this basis they suggested that the extent of amino acid racemisation (epimerisation in the case of isoleucine) may be used to assess the age of materials within and beyond the range of radiocarbon dating. For the past thirty years amino acid racemisation has been extensively applied in Quaternary research as a method of relative and numeric dating, and a particularly large literature has emerged on the subject

  6. Amino Acids and Chirality

    Science.gov (United States)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  7. Acid Mine Drainage Treatment

    National Research Council Canada - National Science Library

    Fripp, Jon

    2000-01-01

    .... Acid mine drainage (AMD) can have severe impacts to aquatic resources, can stunt terrestrial plant growth and harm wetlands, contaminate groundwater, raise water treatment costs, and damage concrete and metal structures...

  8. Amoxicillin and Clavulanic Acid

    Science.gov (United States)

    ... in a class of medications called penicillin-like antibiotics. It works by stopping the growth of bacteria. Clavulanic acid ... It works by preventing bacteria from destroying amoxicillin. Antibiotics will not work for colds, flu, or other viral infections.

  9. Alpha Hydroxy Acids

    Science.gov (United States)

    ... or tenderness (8), chemical burns (6), and increased sunburn (3). The frequency of such reports for skin ... bear a statement that conveys the following information: Sunburn Alert: This product contains an alpha hydroxy acid ( ...

  10. Azetidinic amino acids

    DEFF Research Database (Denmark)

    Bräuner-Osborne, Hans; Bunch, Lennart; Chopin, Nathalie

    2005-01-01

    A set of ten azetidinic amino acids, that can be envisioned as C-4 alkyl substituted analogues of trans-2-carboxyazetidine-3-acetic acid (t-CAA) and/or conformationally constrained analogues of (R)- or (S)-glutamic acid (Glu) have been synthesized in a diastereo- and enantiomerically pure form from...... of two diastereoisomers that were easily separated and converted in two steps into azetidinic amino acids. Azetidines 35-44 were characterized in binding studies on native ionotropic Glu receptors and in functional assays at cloned metabotropic receptors mGluR1, 2 and 4, representing group I, II and III...... beta-amino alcohols through a straightforward five step sequence. The key step of this synthesis is an original anionic 4-exo-tet ring closure that forms the azetidine ring upon an intramolecular Michael addition. This reaction was proven to be reversible and to lead to a thermodynamic distribution...

  11. Valproic Acid and Pregnancy

    Science.gov (United States)

    ... is possible. Studies have found that women with seizure disorders and women with bipolar disorder might have menstrual ... valproic acid to leave your body. Women with epilepsy or bipolar disorder who are planning a pregnancy ...

  12. [Acids in coffee. XI. The proportion of individual acids in the total titratable acid].

    Science.gov (United States)

    Engelhardt, U H; Maier, H G

    1985-07-01

    22 acids in ground roast coffees and instant coffees were determined by GLC of their silyl derivatives (after preseparation by gel electrophoresis) or isotachophoresis. The contribution to the total acidity (which was estimated by titration to pH 8 after cation exchange of the coffee solutions) was calculated for each individual acid. The mentioned acids contribute with 67% (roast coffee) and 72% (instant coffee) to the total acidity. In the first place citric acid (12.2% in roast coffee/10.7% in instant coffee), acetic acid (11.2%/8.8%) and the high molecular weight acids (8%/9%) contribute to the total acidity. Also to be mentioned are the shares of chlorogenic acids (9%/4.8%), formic acid (5.3%/4.6%), quinic acid (4.7%/5.9%), malic acid (3.9%/3%) and phosphoric acid (2.5%/5.2%). A notable difference in the contribution to total acidity between roast and instant coffee was found for phosphoric acid and pyrrolidonecarboxylic acid (0.7%/1.9%). It can be concluded that those two acids are formed or released from e.g. their esters in higher amounts than other acids during the production of instant coffee.

  13. Portable nucleic acid thermocyclers.

    Science.gov (United States)

    Almassian, David R; Cockrell, Lisa M; Nelson, William M

    2013-11-21

    A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies.

  14. Fatty Acid Biosynthesis IX

    DEFF Research Database (Denmark)

    Carey, E. M.; Hansen, Heinz Johs. Max; Dils, R.

    1972-01-01

    # 1. I. [I-14C]Acetate was covalently bound to rabbit mammary gland fatty acid synthetase by enzymic transacylation from [I-14C]acetyl-CoA. Per mole of enzyme 2 moles of acetate were bound to thiol groups and up to I mole of acetate was bound to non-thiol groups. # 2. 2. The acetyl-fatty acid...... synthetase complex was isolated free from acetyl-CoA. It was rapidly hydrolysed at 30°C, but hydrolysis was greatly diminished at o°C and triacetic lactone synthesis occurred. In the presence of malonyl-CoA and NADPH, all the acetate bound to fatty acid synthetase was incorporated into long-chain fatty acids....... Hydrolysis of bound acetate and incorporation of bound acetate into fatty acids were inhibited to the same extent by guanidine hydrochloride. # 3. 3. Acetate was also covalently bound to fatty acid synthetase by chemical acetylation with [I-14C]acetic anhydride in the absence of CoASH. A total of 60 moles...

  15. Acidification and Acid Rain

    Science.gov (United States)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  16. Probe substrate and enzyme source-dependent inhibition of UDP ...

    African Journals Online (AJOL)

    Background: Drug-metabolizing enzymes (DMEs) inhibition based drug-drug interaction and herb-drug interaction severely challenge the R&D process of drugs or herbal ingredients. Objective: To evaluate the inhibition potential of wogonin (an important flavonoid isolated from the root of Scutellaria baicalensis) towards ...

  17. Why is hydrofluoric acid a weak acid?

    Science.gov (United States)

    Ayotte, Patrick; Hébert, Martin; Marchand, Patrick

    2005-11-08

    The infrared vibrational spectra of amorphous solid water thin films doped with HF at 40 K reveal a strong continuous absorbance in the 1000-3275 cm(-1) range. This so-called Zundel continuum is the spectroscopic hallmark for aqueous protons. The extensive ionic dissociation of HF at such low temperature suggests that the reaction enthalpy remains negative down to 40 K. These observations support the interpretation that dilute HF aqueous solutions behave as weak acids largely due to the large positive reaction entropy resulting from the structure making character of the hydrated fluoride ion.

  18. Acid Rain, pH & Acidity: A Common Misinterpretation.

    Science.gov (United States)

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  19. [Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

    Science.gov (United States)

    Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

    2016-03-01

    Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.

  20. Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

    DEFF Research Database (Denmark)

    Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

    2003-01-01

    Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

  1. ORF Alignment: NC_002695 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available yl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial common antigen (ECA); ... ... ... UDP-N-acetyl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacter...-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial com

  2. ORF Alignment: NC_004337 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available yl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial common antigen (ECA); ... ... ... UDP-N-acetyl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacter...-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial com

  3. ORF Alignment: NC_004741 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available yl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial common antigen (ECA); ... ... ... UDP-N-acetyl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacter...-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial com

  4. ORF Alignment: NC_002655 [GENIUS II[Archive

    Lifescience Database Archive (English)

    Full Text Available yl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial common antigen (ECA); ... ... ... UDP-N-acetyl-D-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacter...-mannosaminuronic acid dehydrogenase; ... synthesis of enterobacterial com

  5. Chemistry and electrochemistry in trifluoroacetic acid. Comparison with acetic acid

    International Nuclear Information System (INIS)

    Petit, Gerard

    1972-01-01

    As the trifluoroacetic acid is, with the acetic acid, one of most often used carboxylic acids as solvent, notably in organic chemistry, this research thesis addresses some relatively simple complexing and redox reactions to highlight the peculiar feature of this acid, and to explain its very much different behaviour with respect to acetic acid. The author develops the notion of acidity level in solvents of low dielectric constant. The second part addresses a specific solvent: BF 3 (CH 3 COOH) 2 . The boron trifluoride strengthens the acidity of acetic acid and modifies its chemical and physical-chemical properties. In the third part, the author compares solvent properties of CF 3 COOH and CH 3 COOH. Noticed differences explain why the trifluoroacetic acid is a more interesting reaction environment than acetic acid for reactions such as electrophilic substitutions or protein solubilisation [fr

  6. Domoic Acid Epileptic Disease

    Directory of Open Access Journals (Sweden)

    John S. Ramsdell

    2014-03-01

    Full Text Available Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

  7. Arabidopsis ROCK1 transports UDP-GlcNAc/UDP-GalNAc and regulates ER protein quality control and cytokinin activity

    Czech Academy of Sciences Publication Activity Database

    Niemann, M.C.E.; Bartrina, I.; Ashikov, A.; Weber, H.; Novák, Ondřej; Spíchal, Lukáš; Strnad, Miroslav; Strasser, R.; Bakker, H.; Schmülling, T.; Werner, T.

    2015-01-01

    Roč. 112, č. 1 (2015), s. 291-296 ISSN 0027-8424 R&D Projects: GA MŠk LK21306; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : ROCK1 * cytokinin * CKX Subject RIV: EF - Botanics Impact factor: 9.423, year: 2015

  8. Citric acid by fermentation

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed, R M

    1978-11-30

    Citric acid is produced in 2 stages, in the first of which Escherichia coli KG93 F-is cultured on a substrate consisting of whey permeate to which phosphate and nitrate or urea is added. In the second stage, Hansenula wickerhamii CBS 4308 is cultured on the culture solution from the first stage and the citric acid isolated in the usual manner. Thus, a whey permeate comprising fat 0.20, protein 0.05, lactose 5.0, lactic acid 0.1, and salts 0.6% (Ca 0.06, P 0.06, K 0.16, N 0.03, and NaCl 0.3%) was amended with 1.2 g phosphate/L and 1.0 g NO/sub 3/sup -///L. After introducing the whey permeate into a continuous fermentor, it was inoculated with E. coli K693 F- and allowed to incubate at 37/sup 0/ and pH 7 (Maintained with NH/sub 3/ gas) for 12 h with aeration, thereby producing concentration pyruvic acid. After an additional 6 h cultivation without aeration, the broth was transferred to another fermentor and there inoculated with H. wickerhamii CBS 4308. The second cultivation step was carried out at 30/sup 0/ and a pH of 5 for 24 h with the pH stabilized by NH/sub 3/ gas. To the second stage culture, 0.3 g Fe(CN)/sup 4 -//L was added. The yield of pyruvic acid in the first stage was 32 g/L and the final yield of citric acid was 43 g/L.

  9. 2-arylureidobenzoic acids

    DEFF Research Database (Denmark)

    Valgeirsson, Jon; Nielsen, Elsebet Ø; Peters, Dan

    2003-01-01

    A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent...... on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC(50) values of 1.3, 1...

  10. Whither Acid Rain?

    Directory of Open Access Journals (Sweden)

    Peter Brimblecombe

    2000-01-01

    Full Text Available Acid rain, the environmental cause célèbre of the 1980s seems to have vanished from popular conscience. By contrast, scientific research, despite funding difficulties, has continued to produce hundreds of research papers each year. Studies of acid rain taught much about precipitation chemistry, the behaviour of snow packs, long-range transport of pollutants and new issues in the biology of fish and forested ecosystems. There is now evidence of a shift away from research in precipitation and sulfur chemistry, but an impressive theoretical base remains as a legacy.

  11. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    Science.gov (United States)

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  12. Catalytic acetoxylation of lactic acid to 2-acetoxypropionic acid, en route to acrylic acid

    NARCIS (Netherlands)

    Beerthuis, R.; Granollers, M.; Brown, D.R.; Salavagione, H.J.; Rothenberg, G.; Shiju, N.R.

    2015-01-01

    We present an alternative synthetic route to acrylic acid, starting from the platform chemical lactic acid and using heterogeneous catalysis. To improve selectivity, we designed an indirect dehydration reaction that proceeds via acetoxylation of lactic acid to 2-acetoxypropionic acid. This

  13. Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

    International Nuclear Information System (INIS)

    Shafiq, Mian Umer; Mahmud, Hisham Khaled Ben; Hamid, Mohamed Ali

    2015-01-01

    The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H 3 PO 4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid. (paper)

  14. Usnic acid controls the acidity tolerance of lichens

    International Nuclear Information System (INIS)

    Hauck, Markus; Juergens, Sascha-Rene

    2008-01-01

    The hypotheses were tested that, firstly, lichens producing the dibenzofuran usnic acid colonize substrates characterized by specific pH ranges, secondly, this preferred pH is in a range where soluble usnic acid and its corresponding anion occur in similar concentrations, and thirdly, usnic acid makes lichens vulnerable to acidity. Lichens with usnic acid prefer an ambient pH range between 3.5 and 5.5 with an optimum between 4.0 and 4.5. This optimum is close to the pK a1 value of usnic acid of 4.4. Below this optimum pH, dissolved SO 2 reduces the chlorophyll fluorescence yield more in lichens with than without their natural content of usnic acid. This suggests that usnic acid influences the acidity tolerance of lichens. The putative mechanism of the limited acidity tolerance of usnic acid-containing lichens is the acidification of the cytosol by molecules of protonated usnic acid shuttling protons through the plasma membrane at an apoplastic pH a1 . - Combined field and experimental data suggest that usnic acid makes lichens sensitive to acidity at pH <3.5

  15. Identification of an unintended consequence of Nrf2-directed cytoprotection against a key tobacco carcinogen plus a counteracting chemopreventive intervention

    Science.gov (United States)

    Paonessa, Joseph D.; Ding, Yi; Randall, Kristen L.; Munday, Rex; Argoti, Dayana; Vouros, Paul; Zhang, Yuesheng

    2011-01-01

    Nrf2 is a major cytoprotective gene and is a key chemopreventive target against cancer and other diseases. Here we show that Nrf2 faces a dilemma in defense against 4-aminobiphenyl (ABP), a major human bladder carcinogen from tobacco smoke and other environmental sources. While Nrf2 protected mouse liver against ABP (which is metabolically activated in liver), the bladder level of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP), the predominant ABP-DNA adduct formed in bladder cells and tissues, was markedly higher in Nrf2+/+ mice than in Nrf2−/− mice after ABP exposure. Notably, Nrf2 protected bladder cells against ABP in vitro. Mechanistic investigations showed that the dichotomous effects of Nrf2 could be explained at least partly by upregulation of UDP-glucuronosyltransferase (UGT). Nrf2 promoted conjugation of ABP with glucuronic acid in the liver, increasing urinary excretion of the conjugate. While glucuronidation of ABP and its metabolites is a detoxification process, these conjugates, which are excreted in urine, are known to be unstable in acidic urine, leading to delivery of the parent compounds to bladder. Hence, while higher liver UGT activity may protect the liver against ABP it increases bladder exposure to ABP. These findings raise concerns of potential bladder toxicity when Nrf2-activating chemopreventive agents are used in humans exposed to ABP, especially in smokers. We further demonstrate that 5,6-dihydrocyclopenta[c][1,2]-dithiole-3(4H)-thione (CPDT) significantly inhibits dG-C8-ABP formation in bladder cells and tissues, but does not appear to significantly modulate ABP-catalyzing UGT in liver. Thus, CPDT exemplifies a counteracting solution to the dilemma posed by Nrf2. PMID:21487034

  16. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    Science.gov (United States)

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination.

  17. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    Energy Technology Data Exchange (ETDEWEB)

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  18. Molecular interaction of pinic acid with sulfuric acid

    DEFF Research Database (Denmark)

    Elm, Jonas; Kurtén, Theo; Bilde, Merete

    2014-01-01

    We investigate the molecular interactions between the semivolatile α-pinene oxidation product pinic acid and sulfuric acid using computational methods. The stepwise Gibbs free energies of formation have been calculated utilizing the M06-2X functional, and the stability of the clusters is evaluated...... cluster. The involvement of more than one pinic acid molecule in a single cluster is observed to lead to the formation of favorable (pinic acid)2(H2SO4) and (pinic acid)2(H2SO4)2 clusters. The identified most favorable growth paths starting from a single pinic acid molecule lead to closed structures...

  19. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    Science.gov (United States)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  20. Koetjapic acid chloroform hemisolvate

    Directory of Open Access Journals (Sweden)

    Z. D. Nassar

    2010-06-01

    Full Text Available The asymmetric unit of the title compound, C30H46O4·0.5CHCl3, consists of one koetjapic acid [systematic name: (3R,4aR,4bS,7S,8S,10bS,12aS-7-(2-carboxyethyl-3,4b,7,10b,12a-pentamethyl-8-(prop-1-en-2-yl-1,2,3,4,4a,4b,5,6,7,8,9,10,10b,11,12,12a-hexadecahydrochrysene-3-carboxylic acid] molecule and one half-molecule of chloroform solvent, which is disordered about a twofold rotation axis. The symmetry-independent component is further disordered over two sites, with occupancies of 0.30 and 0.20. The koetjapic acid contains a fused four-ring system, A/B/C/D. The A/B, B/C and C/D junctions adopt E/trans/cis configurations, respectively. The conformation of ring A is intermediate between envelope and half-chair and ring B adopts an envelope conformation whereas rings C and D adopt chair conformations. A weak intramolecular C—H...O hydrogen bond is observed. The koetjapic acid molecules are linked into dimers by two pairs of intermolecular O—H...O hydrogen bonds. The dimers are stacked along the c axis.

  1. Microbial Propionic Acid Production

    Directory of Open Access Journals (Sweden)

    R. Axayacatl Gonzalez-Garcia

    2017-05-01

    Full Text Available Propionic acid (propionate is a commercially valuable carboxylic acid produced through microbial fermentation. Propionic acid is mainly used in the food industry but has recently found applications in the cosmetic, plastics and pharmaceutical industries. Propionate can be produced via various metabolic pathways, which can be classified into three major groups: fermentative pathways, biosynthetic pathways, and amino acid catabolic pathways. The current review provides an in-depth description of the major metabolic routes for propionate production from an energy optimization perspective. Biological propionate production is limited by high downstream purification costs which can be addressed if the target yield, productivity and titre can be achieved. Genome shuffling combined with high throughput omics and metabolic engineering is providing new opportunities, and biological propionate production is likely to enter the market in the not so distant future. In order to realise the full potential of metabolic engineering and heterologous expression, however, a greater understanding of metabolic capabilities of the native producers, the fittest producers, is required.

  2. Acid dip for dosemeter

    International Nuclear Information System (INIS)

    Stewart, J.C.; McWhan, A.F.

    1982-01-01

    Background signal in a PTFE based dosemeter caused by impurities in the PTFE and in the active component such as lithium fluoride is substantially reduced by treating the dosemeter with acid. The optimum treatment involves use of hydrofluoric acid at room temperature for approximately one minute, followed by thorough washing with methanol, and finally drying. This treatment is best applied after the original manufacture of the dosemeters. It may also be applied to existing dosemeters after they have been in use for some time. The treatment produces a permanent effect in reducing both the light induced signal and the non-light induced signal. The process may be applied to all types of dosemeter manufactured from PTFE or other plastics or resins which are able to resist brief exposure to acid. The treatment works particularly well with dosemeters based on PTFE and lithium fluoride. It is also applicable to dosemeters based on calcium sulphate, lithium borate and magnesium borate. Acids which may be used include hydrofluoric, hydrochloric, nitric, phosphoric and sulphuric. (author)

  3. Acid Ceramidase in Melanoma

    DEFF Research Database (Denmark)

    Realini, Natalia; Palese, Francesca; Pizzirani, Daniela

    2016-01-01

    Acid ceramidase (AC) is a lysosomal cysteine amidase that controls sphingolipid signaling by lowering the levels of ceramides and concomitantly increasing those of sphingosine and its bioactive metabolite, sphingosine 1-phosphate. In the present study, we evaluated the role of AC-regulated sphing...

  4. Nucleic acids in circulation

    Indian Academy of Sciences (India)

    Elevated blood levels of extracellular nucleic acids have been reported in various disease conditions; such as ageing and age-related degenerative disorders, cancer; acute and chronic inflammatory conditions, severe trauma and autoimmune disorders. In addition to genomic DNA and nucleosomes, mitochondrial DNA is ...

  5. Salicylic Acid Topical

    Science.gov (United States)

    ... the package label for more information.Apply a small amount of the salicylic acid product to one or two small areas you want to treat for 3 days ... know that children and teenagers who have chicken pox or the flu should not use topical salicylic ...

  6. Acid Rain: Science Projects.

    Science.gov (United States)

    Stubbs, Harriett S.

    1989-01-01

    Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)

  7. Hyaluronic Acid Assays

    DEFF Research Database (Denmark)

    Itenov, Theis S; Kirkby, Nikolai S; Bestle, Morten H

    2015-01-01

    BACKGROUD: Hyaluronic acid (HA) is proposed as a marker of functional liver capacity. The aim of the present study was to compare a new turbidimetric assay for measuring HA with the current standard method. METHODS: HA was measured by a particle-enhanced turbidimetric immunoassay (PETIA) and enzyme...

  8. Multifunctional Cinnamic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Aikaterini Peperidou

    2017-07-01

    Full Text Available Our research to discover potential new multitarget agents led to the synthesis of 10 novel derivatives of cinnamic acids and propranolol, atenolol, 1-adamantanol, naphth-1-ol, and (benzylamino ethan-1-ol. The synthesized molecules were evaluated as trypsin, lipoxygenase and lipid peroxidation inhibitors and for their cytotoxicity. Compound 2b derived from phenoxyphenyl cinnamic acid and propranolol showed the highest lipoxygenase (LOX inhibition (IC50 = 6 μΜ and antiproteolytic activity (IC50 = 0.425 μΜ. The conjugate 1a of simple cinnamic acid with propranolol showed the higher antiproteolytic activity (IC50 = 0.315 μΜ and good LOX inhibitory activity (IC50 = 66 μΜ. Compounds 3a and 3b, derived from methoxylated caffeic acid present a promising combination of in vitro inhibitory and antioxidative activities. The S isomer of 2b also presented an interesting multitarget biological profile in vitro. Molecular docking studies point to the fact that the theoretical results for LOX-inhibitor binding are identical to those from preliminary in vitro study.

  9. Accidents with sulfuric acid

    Directory of Open Access Journals (Sweden)

    Rajković Miloš B.

    2006-01-01

    Full Text Available Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eighteen years (from 1988 till the beginning of 2006 are analyzed in this paper. It is very alarming data that, according to all the recorded accidents, over 1.6 million tons of sulfuric acid were exuded. Although water transport is the safest (only 16.38% of the total amount of accidents in that way 98.88% of the total amount of sulfuric acid was exuded into the environment. Human factor was the common factor in all the accidents, whether there was enough control of the production process, of reservoirs or transportation tanks or the transport was done by inadequate (old tanks, or the accidents arose from human factor (inadequate speed, lock of caution etc. The fact is that huge energy, sacrifice and courage were involved in the recovery from accidents where rescue teams and fire brigades showed great courage to prevent real environmental catastrophes and very often they lost their lives during the events. So, the phrase that sulfuric acid is a real "environmental bomb" has become clearer.

  10. Pantothenic acid and biotin

    Science.gov (United States)

    Pantothenic acid and biotin are types of B vitamins. They are water-soluble, which means that the body can't store them. If the body can't use all of the vitamin, the extra vitamins leave the body through the ...

  11. and amino acids

    Indian Academy of Sciences (India)

    Unknown

    P RABINDRA REDDY* and A MOHAN REDDY. Department of ... The mixed ligand complexes of Cu(II), Ni(II) and Co(II) with uridine and amino acids ..... Sabat M, Satyashur K A and Sundaralingam M 1983 J. Am. Chem. Soc. ... Uemura T, Shimura T, Nakamishi H, Tomahiro T, Nagawa Y and Okuno (Yohmei) H 1991. Inorg.

  12. Lactic acid and lactates

    NARCIS (Netherlands)

    Schreurs, V.V.A.M.

    2010-01-01

    This review aims to integrate the present state of knowledge on lactate metabolism in human and mammalian physiology as far as it could be subject to nutritional interventions. An integrated view on the nutritional, metabolic and physiological aspects of lactic acid and lactates might open a

  13. Origin of fatty acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of fatty acids and membranes is one of the most important events of the prebiotic world because genesis of life required the compartmentalization of molecules. Membranes allowed cells to become enriched with molecules relevant for their evolution and gave rise to gradients convertible into energy. By virtue of their hydrophobic/hydrophilic interface, membranes developed certain enzymatic activities impossible in the aqueous phase. A prebiotic cell is an energy unit but it is also an information unit. It has a past, a present and a future. The biochemistry of fatty acids involves acetylCoA, malonylCoA and an enzyme, acyl synthetase, which joins both molecules. After substitution of the acetyl group in place of the carboxyl group of malonyl derivatives, the chain is reduced and dehydrated to crotonyl derivatives. These molecules can again react with malonylCoA to form unsaturated chain; they can also undergo a new reduction step to form butyryl derivatives which can react with malonylCoA to form a longer aliphatic chain. The formation of malonylCoA consumes ATP. The reduction step needs NADPH and proton. Dehydration requires structural information because the reduction product is chiral (D configuration). It is unlikely that these steps were possible in a prebiotic environment. Thus we have to understand how fatty acids could appear in the prebiotic era. This hypothesis about the origin of fatty acids is based on the chemistry of sulfonium ylides and sulfonium salts. The most well-known among these molecules are S-melthyl-methionine and S-adenosyl methionine. The simplest sulfonium cation is the trimethylsulfonium cation. Chemists have evidence that these products can produce olefin when they are heated or flashed with UV light in some conditions. I suggest that these volatile products can allow the formation of fatty acids chains in atmospheric phase with UV and temperature using methanol as starting material. Different synthetic pathways will be

  14. Fatty acid-producing hosts

    Science.gov (United States)

    Pfleger, Brian F; Lennen, Rebecca M

    2013-12-31

    Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.

  15. Acetic acid extraction from aqueous solutions using fatty acids

    NARCIS (Netherlands)

    IJmker, H.M.; Gramblicka, M.; Kersten, Sascha R.A.; van der Ham, Aloysius G.J.; Schuur, Boelo

    2014-01-01

    A major challenge for production of acetic acid via bio-based routes is cost-effective concentration and purification of the acetic acid from the aqueous solutions, for which liquid–liquid extraction is a possible method. A main challenge in extraction of acetic acid from dilute aqueous solutions is

  16. College Chemistry Students' Mental Models of Acids and Acid Strength

    Science.gov (United States)

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  17. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    Cytotoxic effect of betulinic acid and betulinic acid acetate isolated from Melaleuca cajuput on human myeloid leukemia (HL-60) cell line. ... The cytotoxic effect of betulinic acid (BA), isolated from Melaleuca cajuput a Malaysian plant and its four synthetic derivatives were tested for their cytotoxicity in various cell line or ...

  18. Industrial ecotoxicology "acid rain".

    Science.gov (United States)

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.

  19. Radioimmunoassay for jasmonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Knoefel, H.D.; Brueckner, C.; Kramell, R.; Sembdner, G.; Schreiber, K. (Akademie der Wissenschaften der DDR, Halle/Saale. Inst. fuer Biochemie der Pflanzen)

    1984-01-01

    A radioimmunoassay (RIA) for the natural plant growth regulator jasmonic acid (JA) was developed. The antiserum was raised in rabbits against (+-)-JA linked to bovine serum albumin. As tracer tritium labelled (+-)-JA (spec. act. 7.4 x 10/sup 9/ Bq x mmol/sup -1/) was used. Cross-reactivity studies with compounds structurally related to JA demonstrated the antiserum to be specific for JA, abscisic acid normally present in the same extract does not interfer. The RIA has a detection limit of 2 ng (-)-JA methylester, a measuring range 2-200 ng, and no extensive purification is required prior to estimation. Therefore, in JA analysis the RIA described is superior to GC, HPLC, and bioassay. This new method has been employed for studies on the distribution of JA in different plant organs of the broad bean, Vicia faba L.

  20. Acid corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N G

    1964-04-28

    An acid corrosion inhibitor is prepared by a 2-stage vacuum evaporation of effluents obtained from the ammonia columns of the coking oven plant. The effluent, leaving a scrubber in which the phenols are removed at a temperature of 98$C, passes through a quartz filter and flows into a heated chamber in which it is used for preheating a solution circulating through a vacuum unit, maintaining the temperature of the solution at 55$ to 60$C. The effluent enters a large tank in which it is boiled at 55$ to 60$C under 635 to 640 mm Hg pressure. Double evaporation of this solution yields a very effective acid corrosion inhibitor. Its corrosion-preventing effect is 97.9% compared with 90.1% for thiourea and 88.5% for urotropin under identical conditions.

  1. N-(3-Methylphenylsuccinamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-02-01

    Full Text Available In the crystal structure of the title compound, C11H13NO3, the conformations of the N—H and C=O bonds in the amide segment are anti to each other, and that of the amide H atom is anti to the meta-methyl group in the benzene ring. Furthermore, the conformations of the amide oxygen and the carbonyl O atom of the acid segment are also anti to the adjacent –CH2 groups. The C=O and O—H bonds of the acid group are syn to each other. In the crystal, the molecules are packed into infinite chains through intermolecular N—H...O and O—H...O hydrogen bonds.

  2. N-(3-Chlorophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8ClNO3, the molecular conformation is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond within the maleamic acid unit and the second is a C—H...O hydrogen bond which connects the amide group with the phenyl ring. The maleamic acid unit is essentially planar, with an r.m.s. deviation of 0.044 Å, and makes a dihedral angle of 15.2 (1° with the phenyl ring. In the crystal, intermolecular N—H...O hydrogen bonds link the molecules into C(7 chains running [010].

  3. Mortar fights acid corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-14

    The burning of coal or oil to produce heat required to operate a power boiler also generates a severe corrosion problem within the interior of the duct and stacks used to emit the flue gas into the atmosphere. How can concrete and steel be protected from the effects of acid attack, when the acids are carried in a gas form, or come into direct contact with the steel or concrete from spillage or immersion conditions. Industry in North America has found that the solution to this problem is to build an outside concrete column, in this case of Portland cement, and inside that column, build a totally independent brick liner bonded with Sauereisen mortar.

  4. (Radioiodinated free fatty acids)

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, Jr., F. F.

    1987-12-11

    The traveler participated in the Second International Workshop on Radioiodinated Free Fatty Acids in Amsterdam, The Netherlands where he presented an invited paper describing the pioneering work at the Oak Ridge National Laboratory (ORNL) involving the design, development and testing of new radioiodinated methyl-branched fatty acids for evaluation of heart disease. He also chaired a technical session on the testing of new agents in various in vitro and in vivo systems. He also visited the Institute for Clinical and Experimental Nuclear Medicine in Bonn, West Germany, to review, discuss, plan and coordinate collaborative investigations with that institution. In addition, he visited the Cyclotron Research Center in Liege, Belgium, to discuss continuing collaborative studies with the Osmium-191/Iridium-191m radionuclide generator system, and to complete manuscripts and plan future studies.

  5. Acidity of Scandinavian precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, E; Bordin, G

    1955-01-01

    Data on the pH of the total monthly precipitation at stations of a Swedish network for sampling and chemical analysis of precipitation and atmospheric aerosols during the year July 1953 to June 1954 are presented and discussed, together with the pH data from the first two months of operation of a large pan-Scandinavian net. It is found that well-defined regions of acidity and alkalinity relative to the pH of water in equilibrium with atmospheric carbon dioxide exist, and that these regions persist to such an extent that the monthly deviations from the pattern of the annual mean pH at stations unaffected by local pollution show persistently high acidity, while inland northern stations show equally persistent alkalinity. Some possible reasons for the observed distributions are considered.

  6. Omega-3 fatty acids (image)

    Science.gov (United States)

    Omega-3 fatty acids are a form of polyunsaturated fat that the body derives from food. Omega-3s (and omega-6s) are known as essential fatty acids (EFAs) because they are important for good health. ...

  7. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2007-01-01

    Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness.......Trials have assessed bile acids for patients with viral hepatitis, but no consensus has been reached regarding their usefulness....

  8. Halogenated fatty acids

    DEFF Research Database (Denmark)

    Mu, Huiling; Sundin, Peter; Wesén, Clas

    1997-01-01

    Halogenated fatty acids are the major contributors to organohalogen compounds in lipids of marine mammals, fish, and bivalves. For the initial characterization of these recently noticed compounds, a determination of the halogen concentration has usually been combined with some lipid isolation......), atomic emission spectrometry, and mass spectrometry. For most environmental samples, chlorinated FAMEs must be enriched prior to GC. ELCD is a useful detection method for indicating halogenated FAMEs in the chromatograms, and tentative identification of the halogenated species can be obtained...

  9. Accidents with sulfuric acid

    OpenAIRE

    Rajković Miloš B.

    2006-01-01

    Sulfuric acid is an important industrial and strategic raw material, the production of which is developing on all continents, in many factories in the world and with an annual production of over 160 million tons. On the other hand, the production, transport and usage are very dangerous and demand measures of precaution because the consequences could be catastrophic, and not only at the local level where the accident would happen. Accidents that have been publicly recorded during the last eigh...

  10. Sources of atmospheric acidity

    International Nuclear Information System (INIS)

    Clarke, A.G.

    1992-01-01

    The emissions of acid gases from anthropogenic sources and their impact on the environment are the main concern of this book. However, that impact can only be assessed if all the naturally occurring sources of these gases are also known and can be quantified. Given the widely dispersed nature of the natural sources and the problems of measurement of trace species at low concentrations, often in remote regions, the quantification is a very difficult task. Nevertheless, considerable progress has been made over the last decade. In this chapter both man-made and natural sources of atmospheric acidity will be reviewed, but the emphasis will be placed not so much on the global balances as on the scale of the natural sources in relation to the man-made sources. This requires that the very uneven geographical distribution of emissions and the lifetime of individual chemical species be taken into account. The emissions considered are sulphur compounds, nitrogen compounds, chlorine compounds and organic acids. The anthropogenic sources discussed are the combustion of fossil fuels and certain industrial processes. Emissions data for anthropogenic sources are given for the United Kingdom, Europe, USA and globally. A list of 95 references is given. (Author)

  11. Whence the acid raindrop

    International Nuclear Information System (INIS)

    Heaton, T.H.E.

    1987-01-01

    Absorption of NO 2 can cause damage in animals and plants and, if present trends for NO x emissions continue, their by-product nitric acid may soon overtake sulphuric acid as the main acidifying agent of 'acid' rain. In response to this problem the feasibility of reducing NO x emissions from power stations is being studied. Although there can be no doubt that these expensive controls are desirable, their benefits are difficult to predict for two reasons: NO x is not only emitted by fuel combustion and the degree to which an industrialised country benefits from the implementation of NO x emission controls depends on how much its pollutant 'fall out' is immediately returned from the atmosphere, and how much is exported to neighbouring countries. The above factors involve questions regarding the source and reaction mechanisms for nitrogen compounds in the atmosphere. Because stable isotope ratio analysis has proved to be of value in providing answers to such questions in other environments, an investigation of the 15 N/ 14 N ratios of atmospheric gases (NO x , NH 3 ) and their solution products in rain (NO 3 , NH + 4 ) seemed to be justified

  12. Hepatic Toxicity of Perfluorocarboxylic Acids.

    Science.gov (United States)

    1996-07-01

    1995). 3. N. V. Reo, C. M. Goecke, L. Narayanan, and B. M. Jarnot. "Effects of Perfluoro-n-octanoic Acid , Perfluoro-n-decanoic Acid , and Clofibrate ...Artz, and B. M. Jarnot: "ILiver Phosphorous Metabolic Response to Perfluorocarboxylic Acids and Clofibrate in Rats and Guinea Pigs: A 31 P NMR Study...Peroxisome Induction by Perfluoro-n-decanoic Acid and Clofibrate in the Rat: Proliferation Versus Activity." International Society for the Study of

  13. Acids and bases solvent effects on acid-base strenght

    CERN Document Server

    Cox, Brian G

    2013-01-01

    Acids and bases are ubiquitous in chemistry. Our understanding of them, however, is dominated by their behaviour in water. Transfer to non-aqueous solvents leads to profound changes in acid-base strengths and to the rates and equilibria of many processes: for example, synthetic reactions involving acids, bases and nucleophiles; isolation of pharmaceutical actives through salt formation; formation of zwitter- ions in amino acids; and chromatographic separation of substrates. This book seeks to enhance our understanding of acids and bases by reviewing and analysing their behaviour in non-aqueous solvents. The behaviour is related where possible to that in water, but correlations and contrasts between solvents are also presented.

  14. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    Science.gov (United States)

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-06

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  15. Molecular Structure of Nucleic Acids

    Indian Academy of Sciences (India)

    Molecular Structure of Nucleic Acids. A Structure for Deoxyribose Nucleic Acid. J. D. Watson and F. H. C. Crick. Medical Research Council Unit for the Study of the Molecular Structure of Biological. Systems, Cavendish Laboratory, Cambridge. April 2. We wish to suggest a structure for the salt of deoxyribose nucleic acid ...

  16. Fumaric acid production by fermentation

    NARCIS (Netherlands)

    Roa Engel, C.A.; Straathof, A.J.J.; Zijlmans, T.W.; Van Gulik, W.M.; Van der Wielen, L.A.M.

    2008-01-01

    Abstract The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid

  17. Pantothenic acid biosynthesis in zymomonas

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  18. Danburite decomposition by hydrochloric acid

    International Nuclear Information System (INIS)

    Mamatov, E.D.; Ashurov, N.A.; Mirsaidov, U.

    2011-01-01

    Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by hydrochloric acid. The interaction of boron containing ores of Ak-Arkhar Deposit of Tajikistan with mineral acids, including hydrochloric acid was studied. The optimal conditions of extraction of valuable components from danburite composition were determined. The chemical composition of danburite of Ak-Arkhar Deposit was determined as well. The kinetics of decomposition of calcined danburite by hydrochloric acid was studied. The apparent activation energy of the process of danburite decomposition by hydrochloric acid was calculated.

  19. Waste acid detoxification and reclamation

    International Nuclear Information System (INIS)

    Brouns, T.M.; Stewart, T.L.

    1988-01-01

    Economically feasible processes that reduce the volume, quantity, and toxicity of metal-bearing waste acids by reclaiming, reusing, and recycling spent acids and metal salts are being developed and demonstrated. The acids used in the demonstrations are generated during metal-finishing operations used in nuclear fuel fabrication; HF-HNO 3 , HNO 3 , and HNO 3 -H 2 SO 4 wastes result from Zr etching, Cu stripping, and chemical milling of U. At discharge, wastes contain high concentrations of acid and one major metal impurity. The waste minimization process used to reclaim acid from these three streams incorporates three processes for acid regeneration and reclamation. Normally, HNO 3 remains in the bottoms when an aqueous acid solution is distilled; however, in the presence of H 2 SO 4 , HNO 3 will distill to the overhead stream. In this process, nitrates and fluorides present as free acid and metal salts can be reclaimed as acid for recycle to the metal-finishing processes. Uranium present in the chemical milling solution can be economically recovered from distillation bottoms and refined. Using acid distillation, the volume of chemical milling solution discharged as waste can be reduced by as much as 60% depending on the H 2 SO 4 concentration. A payback period of 2.2 years has been estimated for this process. The development and demonstration of precipitation and distillation processes for detoxification and reclamation of waste acid is supported by the US Department of Energy's Hazardous Waste Remedial Actions Program (HAZWRAP)

  20. Effects of Andrographis paniculata and Orthosiphon stamineus extracts on the glucuronidation of 4-methylumbelliferone in human UGT isoforms.

    Science.gov (United States)

    Ismail, Sabariah; Hanapi, Nur Aziah; Ab Halim, Mohd Rohaimi; Uchaipichat, Verawan; Mackenzie, Peter I

    2010-05-14

    The effects of Andrographis paniculata and Orthosiphon stamineus extracts on the in vitro glucuronidation of 4-methylumbelliferone (4MU) by recombinant human UGTs, UGT1A1, UGT1A3, UGT1A6, UGT1A7, UGT1A8, UGT1A10, UGT2B7 and UGT2B15 were determined. The potential inhibitory effects of both of the extracts on the activity of each of the UGT isoforms were investigated using 4MU as the substrate. Incubations contained UDP-glucuronic acid (UDPGA) as the cofactor, MgCl(2), cell lysate of respective isoform, and 4MU at the approximate apparent K(m) or S(50) value of each isoform. Final concentrations of Andrographis paniculata and Orthosiphon stamineus extracts used were 0.025, 0.25, 2.5, 25 and 50 microg/mL and 0.01, 0.10, 1.0, 10 and 50 microg/mL respectively. Both extracts variably inhibited the activity of most of the isoforms in a concentration dependent manner. Andrographis paniculata extract was the better inhibitor of all the isoforms studied (IC(50) 1.70 microg/mL for UGT1A3, 2.57 microg/mL for UGT1A8, 2.82 microg/mL for UGT2B7, 5.00 micorg/mL for UGT1A1, 5.66 microg/mL for UGT1A6, 9.88 microg/mL for UGT1A7 and 15.66 microg/mL for UGT1A10). Both extracts showed less than 70% inhibition of UGT2B15, so the IC(50) values were >50 microg/mL. The inhibition of human UGTs by Andrographis paniculata and Orthosiphon stamineus extracts in vitro suggests a potential for drug-herbal extract interactions in the therapeutic setting.

  1. New Acid Combination for a Successful Sandstone Acidizing

    Science.gov (United States)

    Shafiq, M. U.; Mahmud, H. K. B.; Rezaee, R.

    2017-05-01

    With the development of new enhanced oil recovery techniques, sandstone acidizing has been introduced and played a pivotal role in the petroleum industry. Different acid combinations have been applied, which react with the formation, dissolve the soluble particles; thus increase the production of hydrocarbons. To solve the problems which occurred using current preflush sandstone acidizing technology (hydrochloric acid); a new acid combination has been developed. Core flooding experiments on sandstone core samples with dimensions 1.5 in. × 3 in. were conducted at a flow rate of 2 cm3/min. A series of hydrochloric-acetic acid mixtures with different ratios were tested under 150°F temperature. The core flooding experiments performed are aimed to dissolve carbonate, sodium, potassium and calcium particles from the core samples. These experiments are followed by few important tests which include, porosity-permeability, pH value, Inductively Coupled Plasma (ICP) analysis and Nuclear Magnetic Resonance (NMR measurements). All the results are compared with the results of conventional hydrochloric acid technology. NMR and porosity analysis concluded that the new acid combination is more effective in creating fresh pore spaces and thus increasing the reservoir permeability. It can be seen from the pore distribution before and after the acidizing. Prior applying acid; the large size of pores appears most frequently in the pore distribution while with the applied acid, it was found that the small pore size is most the predominant of the pore distribution. These results are validated using ICP analysis which shows the effective removal of calcium and other positive ions from the core sample. This study concludes that the combination of acetic-hydrochloric acid can be a potential candidate for the preflush stage of sandstone acidizing at high temperature reservoirs.

  2. Urban acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Conlan, D.E.; Longhurst, J.W.S.; Gee, D.R.; Hare, S.E.

    1991-07-01

    In this document results from the Greater Manchester Acid Deposition Survey (GMADS), an urban precipitation chemistry network, for 1990 are presented. Full analytical methods are described along with the precision and accuracy of the methods used. The spatial variability of precipitation chemistry and deposition over this urban region was investigated using a network of twenty collectors. Concentrations of non marine sulphate, ammonium, calcium and hydrogen, and nitrogen dioxide gas concentrations all show significant spatial variability. The spatial variability of the deposition rates of non marine sulphate, nitrate, ammonium, hydrogen and calcium were significant. (Author).

  3. Synthesis of aminoaldonic acids

    DEFF Research Database (Denmark)

    Jørgensen, Christel Thea

    With the aim of synthesising aminoaldonic acids, two 2-acetamido-2-deoxyaldonolactones with D-galacto (6) and D-arabino (11) configuration were prepared from acetylated sugar formazans in analogy with a known procedure. Empolying the same procedure to acetylated sugar phenylhydrazones gave mixtures...... and 82, respectively. The aminolactone 84 was converted into the corresponding amino sugar 89.With the aim of synthesising substrates for the Pictet-Spengler reaction three 4-aldehydo acetamidodideoxytetronolactones 92, 97 and 103 were prepared by periodate cleavage of the corresponding hexonolactones...

  4. Folic Acid: MedlinePlus Health Topic

    Science.gov (United States)

    ... acid in diet (Medical Encyclopedia) Also in Spanish Topic Image MedlinePlus Email Updates Get Folic Acid updates ... acid - test Folic acid in diet Related Health Topics Vitamins National Institutes of Health The primary NIH ...

  5. Solid acid catalysis from fundamentals to applications

    CERN Document Server

    Hattori, Hideshi

    2014-01-01

    IntroductionTypes of solid acid catalystsAdvantages of solid acid catalysts Historical overviews of solid acid catalystsFuture outlookSolid Acids CatalysisDefinition of acid and base -Brnsted acid and Lewis acid-Acid sites on surfacesAcid strengthRole of acid sites in catalysisBifunctional catalysisPore size effect on catalysis -shape selectivity-Characterization of Solid Acid Catalysts Indicator methodTemperature programmed desorption (TPD) of ammoniaCalorimetry of adsorption of basic moleculesInfrare

  6. Age-related mechanism and its relationship with secondary metabolism and abscisic acid in Aristotelia chilensis plants subjected to drought stress.

    Science.gov (United States)

    González-Villagra, Jorge; Rodrigues-Salvador, Acácio; Nunes-Nesi, Adriano; Cohen, Jerry D; Reyes-Díaz, Marjorie M

    2018-03-01

    Drought stress is the most important stress factor for plants, being the main cause of agricultural crop loss in the world. Plants have developed complex mechanisms for preventing water loss and oxidative stress such as synthesis of abscisic acid (ABA) and non-enzymatic antioxidant compounds such as anthocyanins, which might help plants to cope with abiotic stress as antioxidants and for scavenging reactive oxygen species. A. chilensis (Mol.) is a pioneer species, colonizing and growing on stressed and disturbed environments. In this research, an integrated analysis of secondary metabolism in Aristotelia chilensis was done to relate ABA effects on anthocyanins biosynthesis, by comparing between young and fully-expanded leaves under drought stress. Plants were subjected to drought stress for 20 days, and physiological, biochemical, and molecular analyses were performed. The relative growth rate and plant water status were reduced in stressed plants, with young leaves significantly more affected than fully-expanded leaves beginning from the 5th day of drought stress. A. chilensis plants increased their ABA and total anthocyanin content and showed upregulation of gene expression when they were subjected to severe drought (day 20), with these effects being higher in fully-expanded leaves. Multivariate analysis indicated a significant positive correlation between transcript levels for NCED1 (9-cis-epoxycarotenoid dioxygenase) and UFGT (UDP glucose: flavonoid-3-O-glucosyltransferase) with ABA and total anthocyanin, respectively. Thus, this research provides a more comprehensive analysis of the mechanisms that allow plants to cope with drought stress. This is highlighted by the differences between young and fully-expanded leaves, showing different sensibility to stress due to their ability to synthesize anthocyanins. In addition, this ability to synthesize different and high amounts of anthocyanins could be related to higher NCED1 and MYB expression and ABA levels

  7. Cloning of genes related to aliphatic glucosinolate metabolism and the mechanism of sulforaphane accumulation in broccoli sprouts under jasmonic acid treatment.

    Science.gov (United States)

    Guo, Liping; Yang, Runqiang; Gu, Zhenxin

    2016-10-01

    Cytochrome P450 79F1 (CYP79F1), cytochrome P450 83A1 (CYP83A1), UDP-glucosyltransferase 74B1 (UGT74B1), sulfotransferase 18 (ST5b) and flavin-containing monooxygenase GS-OX1 (FMOGS - OX1 ) are important enzymes in aliphatic glucosinolate biosynthesis. In this study, their full-length cDNA in broccoli was firstly cloned, then the mechanism of sulforaphane accumulation under jasmonic acid (JA) treatment was investigated. The full-length cDNA of CYP79F1, CYP83A1, UGT74B1, ST5b and FMOGS - OX1 comprised 1980, 1652, 1592, 1378 and 1623 bp respectively. The increase in aliphatic glucosinolate accumulation in broccoli sprouts treated with JA was associated with elevated expression of genes in the aliphatic glucosinolate biosynthetic pathway. Application of 100 µmol L(-1) JA increased myrosinase (MYR) activity but did not affect epithiospecifier protein (ESP) activity in broccoli sprouts, which was supported by the expression of MYR and ESP. Sulforaphane formation in 7-day-old sprouts treated with 100 µmol L(-1) JA was 3.36 and 1.30 times that in the control and 300 µmol L(-1) JA treatment respectively. JA enhanced the accumulation of aliphatic glucosinolates in broccoli sprouts via up-regulation of related gene expression. Broccoli sprouts treated with 100 µmol L(-1) JA showed higher sulforphane formation than those treated with 300 µmol L(-1) JA owing to the higher glucoraphanin content and myrosinase activity under 100 µmol L(-1) JA treatment. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Uracil in formic acid hydrolysates of deoxyribonucleic acid

    Science.gov (United States)

    Schein, Arnold H.

    1966-01-01

    1. When DNA is hydrolysed with formic acid for 30min. at 175° and the hydrolysate is chromatographed on paper with propan-2-ol–2n-hydrochloric acid, in addition to expected ultraviolet-absorbing spots corresponding to guanine, adenine, cytosine and thymine, an ultraviolet-absorbing region with RF similar to that of uracil can be detected. Uracil was separated from this region and identified by its spectra in acid and alkali, and by its RF in several solvent systems. 2. Cytosine, deoxyribocytidine and deoxyribocytidylic acid similarly treated with formic acid all yielded uracil, as did a mixture of deoxyribonucleotides. 3. Approx. 4% of deoxyribonucleotide cytosine was converted into uracil by the formic acid treatment. ImagesFig. 1. PMID:5949371

  9. Uric acid nephrolithiasis: An update.

    Science.gov (United States)

    Cicerello, Elisa

    2018-04-01

    Uric acid nephrolithiasis appears to increase in prevalence. While a relationship between uric acid stones and low urinary pH has been for long known, additional association with various metabolic conditions and pathophysiological basis has recently been elucidated. Some conditions such as diabetes and metabolic syndrome disease, excessive dietary intake, and increased endogenous uric acid production and/or defect in ammoniagenesis are associated with low urinary pH. In addition, the phenomenon of global warming could result in an increase in areas with greater climate risk for uric acid stone formation. There are three therapeutic steps to be taken for management of uric acid stones: identification of urinary pH profiles, assessment of urinary volume status, and identification of disorders leading to excessive uric acid production. However, the most important factor for uric acid stone formation is acid urinary pH, which is a prerequisite for uric acid precipitation. This article reviews recent insights into the pathophysiology of uric acid stones and their management.

  10. Bile Acid Metabolism and Signaling

    Science.gov (United States)

    Chiang, John Y. L.

    2015-01-01

    Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684

  11. Electrolytic nature of aqueous sulfuric acid. 2. Acidity.

    Science.gov (United States)

    Fraenkel, Dan

    2012-09-27

    In part 1 of this study, I reported that the Debye-Hückel limiting law and the smaller-ion shell (SiS) model of strong electrolyte solutions fit nicely with the experimental mean ionic activity coefficient (γ(±)) of aqueous sulfuric acid as a function of concentration and of temperature when the acid is assumed to be a strong 1-3 electrolyte. Here, I report that the SiS-derived activity coefficient of H(+), γ(H(+)), of the 1-3 acid is comparable to that of aqueous HCl. This agrees with titration curves showing, as well-known, that sulfuric acid in water is parallel in strength to aqueous HCl. The calculated pH is in good accord with the Hammett acidity function, H(0), of aqueous sulfuric acid at low concentration, and differences between the two functions at high concentration are discussed and explained. This pH-H(0) relation is consistent with the literature showing that the H(0) of sulfuric acid (in the 1-9 M range) is similar to those of HCl and the other strong mineral monoprotic acids. The titration of aqueous sulfuric acid with NaOH does not agree with the known second dissociation constant of 0.010 23; rather, the constant is found to be ~0.32 and the acid behaves upon neutralization as a strong diprotic acid practically dissociating in one step. A plausible reaction pathway is offered to explain how the acid may transform, upon base neutralization, from a dissociated H(4)SO(5) (as 3H(+) and HSO(5)(3-)) to a dissociated H(2)SO(4) even though the equilibrium constant of the reaction H(+) + HSO(5)(3-) ↔ SO(4)(2-) + H(2)O, at 25 °C, is 10(-37) (part 1).

  12. Counter current extraction of phosphoric acid: Food grade acid production

    International Nuclear Information System (INIS)

    Shlewit, H.; AlIbrahim, M.

    2009-01-01

    Extraction, scrubbing and stripping of phosphoric acid from the Syrian wet-phosphoric acid was carried out using Micro-pilot plant of mixer settler type of 8 l/h capacity. Tributyl phosphate (TBP)/di-isopropyl ether (DIPE) in kerosene was used as extractant. Extraction and stripping equilibrium curves were evaluated. The number of extraction and stripping stages to achieve the convenient and feasible yield was determined. Detailed flow sheet was suggested for the proposed continuous process. Data obtained include useful information for the design of phosphoric acid extraction plant. The produced phosphoric acid was characterized using different analytical techniques. (author)

  13. Acidizing reservoirs while chelating iron with sulfosalicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    McLaughlin, W A; Berkshire, D C

    1980-09-30

    A well treating process is described in which an aqueous solution of a strong acid capable of dissolving solids in a manner increasing the permeability of a subterranean earth formation is injected into a subterranean reservoir that contains an asphaltenic oil. At least the first injected portion of the aqueous acid and a solution or homogeneous dispersion of at least enough 5-sulfosalicylic acid to chelate with and prevent the formation of iron-asphaltene solids are included with substantially all of the ferric ions that become dissolved within the strong acid solution that enters the earth formation. 10 claims.

  14. Danburite decomposition by sulfuric acid

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Mamatov, E.D.; Ashurov, N.A.

    2011-01-01

    Present article is devoted to decomposition of danburite of Ak-Arkhar Deposit of Tajikistan by sulfuric acid. The process of decomposition of danburite concentrate by sulfuric acid was studied. The chemical nature of decomposition process of boron containing ore was determined. The influence of temperature on the rate of extraction of boron and iron oxides was defined. The dependence of decomposition of boron and iron oxides on process duration, dosage of H 2 SO 4 , acid concentration and size of danburite particles was determined. The kinetics of danburite decomposition by sulfuric acid was studied as well. The apparent activation energy of the process of danburite decomposition by sulfuric acid was calculated. The flowsheet of danburite processing by sulfuric acid was elaborated.

  15. Recovering uranium from phosphoric acid

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Wet-process phosphoric acid contains a significant amount of uranium. This uranium totals more than 1,500 tons/yr in current U.S. acid output--and projections put the uranium level at 8,000 tons/yr in the year 2000. Since the phosphoric acid is a major raw material for fertilizers, uranium finds its way into those products and is effectively lost as a resource, while adding to the amount of radioactive material that can contaminate the food chain. So, resource-conservation and environmental considerations both make recovery of the uranium from phosphoric acid desirable. This paper describes the newly developed process for recovering uranium from phosphoric acid by using solvent-extraction technique. After many extractants had been tested, the researchers eventually selected the combination of di (2-ethylhexyl) phosphoric acid (DEPA) and trioctylphosphine oxide (TOPO) as the most suitable. The flowscheme of the process is included

  16. Acid mine drainage

    Science.gov (United States)

    Bigham, Jerry M.; Cravotta, Charles A.

    2016-01-01

    Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

  17. Dicarboxylic acids from electric discharge

    Science.gov (United States)

    Zeitman, B.; Chang, S.; Lawless, J. G.

    1974-01-01

    An investigation was conducted concerning the possible synthesis of a suite of dicarboxylic acids similar to that found in the Murchison meteorite. The investigation included the conduction of a chemical evolution experiment which simulated electric discharge through the primitive atmosphere of the earth. The suite of dicarboxylic acids obtained in the electric discharge experiment is similar to that of the Murchison meteorite, except for the fact that 2-chlorosuccinic acid is present in the spark discharge.

  18. Uranium extraction from phosphoric acid

    International Nuclear Information System (INIS)

    Araujo Figueiredo, C. de

    1984-01-01

    The recovery of uranium from phosphoric liquor by two extraction process is studied. First, uranium is reduced to tetravalent condition and is extracted by dioctypyrophosphoric acid. The re-extraction is made by concentrated phosphoric acid with an oxidizing agent. The re-extract is submitted to the second process and uranium is extracted by di-ethylhexilphosphoric acid and trioctylphosphine oxide. (M.A.C.) [pt

  19. Acid precipitation literature review

    Energy Technology Data Exchange (ETDEWEB)

    Seip, H M; Andersen, B; Andersson, G; Hov, Oe; Kucera, V; Moseholm, L

    1986-01-01

    There is an increasing number of publications on acid deposition and related phenomena. Interest in these topics has also been reflected in a considerable number of meetings and conferences in this field. The largest of these in 1985 was the ''International Symposium on Acidic Precipitation'' (Muskoka, Ontario). Most work so far has been carried out in North America and Europe. There is, however, an increasing interest in obtaining a better picture of sensitive areas and possible acidification in other parts of the world. Anthropogenic SO/sub 2/ emissions have been estimated to be (in TgSyr/sup -1/): 2.4 (Africa), 4.1 (South America), 0.7 (Ocenia), and 18.3 (Asia). The largest increase during the last decade has been in Asia. Based on Studies of precipitation in remote areas it has been suggested that the natural background concentration for sulphate in many areas should be about 6 ..mu..eq 1/sup -1/. A new study of sulphate and nitrate in Greenland snow showed that both ions increased by a factor of about 2 from 1895 to 1978. The concentrations of SO/sub 2/ at Norwegian rural sites show a decreasing trend since late 1970s, while concentrations of sulphate in air show no clear trend. More reliable models for transformation, transport and deposition of chemicals are being developed, including three-dimensional grid models to describe episodes of elevated pollution levels lasting for a few days. Model calculations indicate that control of hydrocarbon (HC) emissions is much more efficient in reducing the ozone level in southern Scandinavia in episodes influenced by long-range transported pollutants than NO/sub x/ control of combined NO/sub x/ and HC control. 36 refs. (EG).

  20. A radioimmunoassay for abscisic acid

    International Nuclear Information System (INIS)

    Walton, D.; Dashek, W.; Galson, E.

    1979-01-01

    We have developed a radioimmunoassay (RIA) for abscisic acid (ABA) in the 0.1 ng to 2.5 ng range. Antibodies were obtained from rabbits immunized with ABA bound via its carboxyl group to bovine serum albumin. Cross-reactivity studies indicate that ABA esters are completely cross-reactive with ABA, while trans, trans abscisic acid (t-ABA) phaseic acid (PA) and dihydrophaseic acid (DPA) have much lower but significant cross-reactivities. Purification methods which reduce the levels of cross-reacting substances are described. (orig.) 891 AJ/orig. 892 MKO [de

  1. Acid digestion of organic materials

    International Nuclear Information System (INIS)

    Capp, P.D.

    1988-01-01

    To overcome the high temperatures involved in straight incineration of organic waste and the difficulty of extracting actinides from the ash various research establishments throughout the world, including Winfrith and Harwell in the UK, have carried out studies on an alternative chemical combustion method known as acid digestion. The basis of the technique is to digest the waste in concentrated sulphuric acid containing a few percent of nitric acid at a temperature of about 250 0 C. Acid digestion residues consist mainly of non-refractory inorganic sulphates and oxides from which any actinide materials can easily be extracted. (author)

  2. [Fatty acids in confectionery products].

    Science.gov (United States)

    Daniewski, M; Mielniczuk, E; Jacórzyński, B; Pawlicka, M; Balas, J; Filipek, A; Górnicka, M

    2000-01-01

    The content of fat and fatty acids in 144 different confectionery products purchased on the market in Warsaw region during 1997-1999 have been investigated. In examined confectionery products considerable variability of both fat and fatty acids content have been found. The content of fat varied from 6.6% (coconut cookies) up to 40% (chocolate wafers). Saturated fatty acids were present in both cis and trans form. Especially trans fatty acids reach (above 50%) were fats extracted from nut wafers, coconuts wafers.

  3. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    Science.gov (United States)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  4. Zirconium for nitric acid solutions

    International Nuclear Information System (INIS)

    Yau, T.L.

    1984-01-01

    The excellent corrosion resistance of zirconium in nitric acid has been known for over 30 years. Recently, there is an increasing interest in using zirconium for nitric acid services. Therefore, an extensive research effort has been carried out to achieve a better understanding of the corrosion properties of zirconium in nitric acid. Particular attention is paid to the effect of concentration, temperature, structure, solution impurities, and stress. Immersion, autoclave, U-bend, and constant strain-rate tests were used in this study. Results of this study indicate that the corrosion resistance of zirconium in nitric acid is little affected by changes in temperature and concentration, and the presence of common impurities such as seawater, sodium chloride, ferric chloride, iron, and stainless steel. Moreover, the presence of seawater, sodium chloride, ferric chloride, and stainless steel has little effect on the stress corrosion craking (SCC) susceptibility of zirconium in 70% nitric acid at room temperatures. However, zirconium could be attacked by fluoride-containing nitric acid and the vapors of chloride-containing nitric acid. Also, high sustained tensile stresses should be avoided when zirconium is used to handle 70% nitric acid at elevated temperatures or > 70% nitric acid

  5. Valproic Acid Induced Hyperammonaemic Encephalopathy

    International Nuclear Information System (INIS)

    Amanat, S.; Shahbaz, N.; Hassan, Y.

    2013-01-01

    Objective: To observe clinical and laboratory features of valproic acid-induced hyperammonaemic encephalopathy in patients taking valproic acid. Methods: Observational study was conducted at the Neurology Department, Dow University of Health Sciences, Civil Hospital, Karachi, from February 26, 2010 to March 20, 2011. Ten patients on valproic acid therapy of any age group with idiopathic or secondary epilepsy, who presented with encephalopathic symptoms, were registered and followed up during the study. Serum ammonia level, serum valproic acid level, liver function test, cerebrospinal fluid examination, electroencephalogram and brain imaging of all the patients were done. Other causes of encephalopathy were excluded after clinical and appropriate laboratory investigations. Microsoft Excel 2007 was used for statistical analysis. Results: Hyperammonaemia was found in all patients with encephalopathic symptoms. Rise in serum ammonia was independent of dose and serum level of valproic acid. Liver function was also found to be normal in 80% (n=8) of the patients. Valproic acid was withdrawn in all patients. Three (30%) patients improved only after the withdrawal of valproic acid. Six (60%) patients improved after L-Carnitine replacement, one (10%) after sodium benzoate. On followup, serum ammonia had reduced to normal in five (50%) patients and to more than half of the baseline level in two (20%) patients. Three (30%) patients were lost to followup after complete clinical improvement. Conclusion: Within therapeutic dose and serum levels, valproic acid can cause symptomatic hyperammonaemia resulting in encephalopathy. All patients taking valproic acid presenting with encephalopathic symptoms must be monitored for the condition. (author)

  6. ACETIC ACID AND A BUFFER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent.......The present invention relates to a composition comprising : a) 0.01-20% wt/wt acetic acid and b) a physiologically tolerable buffer capable of maintaining acetic acid at a pH in the range of 2-7; and use of such a composition as an antimicrobial agent....

  7. How salicylic acid takes transcriptional control over jasmonic acid signaling

    NARCIS (Netherlands)

    Caarls, Lotte|info:eu-repo/dai/nl/371746213; Pieterse, Corné M J|info:eu-repo/dai/nl/113115113; van Wees, Saskia C M|info:eu-repo/dai/nl/185445373

    2015-01-01

    Transcriptional regulation is a central process in plant immunity. The induction or repression of defense genes is orchestrated by signaling networks that are directed by plant hormones of which salicylic acid (SA) and jasmonic acid (JA) are the major players. Extensive cross-communication between

  8. C-11 Acid and the Stereochemistry of Abietic Acid

    Indian Academy of Sciences (India)

    IAS Admin

    While many features, like the phenanthrene-type of fusion of the three ... thought to contain the original ring A of abietic acid, retaining the. 'nuclear methyl .... Thinking that the anhydride he had obtained by the action of heat on the C-11 acid ...

  9. Composition of amino acids, fatty acids and dietary fibre monomers ...

    African Journals Online (AJOL)

    There is increasing demand for sources of energy and non-meat protein with balanced amino acid profiles worldwide. Nuts are rich in protein and essential amino acids, and have a high energy value due to their high fat content. Kernels from two wild fruits in Mozambique, Adansonia digitata and Sclerocarya birrea, were ...

  10. Application of citric acid in acid stimulation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Alkhaldi, M.H.; Sarma, H.K. [Adelaide Univ., Adelaide (Australia); Nasr-el-Din, H.A. [Texas A and M Univ., College Station, TX (United States)

    2009-07-01

    A rotating disk apparatus was used to investigate mass transfer during the reaction of citric acid with calcite. The study evaluated the effects of initial acid concentrations, temperature, and disk rotational speed on the effective diffusion coefficient of citric acid. The diffusion coefficient was calculated at 25, 40, and 50 degrees C using various citric acid concentrations. The study indicated that the coefficient was a function of the interactions between calcium citrate precipitation and counter calcium ions. At high acid concentrations, the effects of calcium citrate precipitation and counter calcium ions were significant. The calculated citric acid diffusion coefficients were not comparable with measured effective diffusion coefficients using the rotating disk. At lower initial citric acid concentrations, the effects of both calcium citrate precipitation and counter calcium ions on citric acid diffusivity were minimal. It was concluded that temperature effects on the diffusion coefficient followed Arrhenius law. Activation energy was equal to 37.9 kJ/mol. 34 refs., 4 tabs., 13 figs.

  11. Bile acid analysis in human disorders of bile acid biosynthesis

    NARCIS (Netherlands)

    Vaz, Frédéric M.; Ferdinandusse, Sacha

    2017-01-01

    Bile acids facilitate the absorption of lipids in the gut, but are also needed to maintain cholesterol homeostasis, induce bile flow, excrete toxic substances and regulate energy metabolism by acting as signaling molecules. Bile acid biosynthesis is a complex process distributed across many cellular

  12. Peptide Nucleic Acids Having Amino Acid Side Chains

    DEFF Research Database (Denmark)

    1998-01-01

    A novel class of compounds, known as peptide nucleic acids, bind complementary DNA and RNA strands more strongly than the corresponding DNA or RNA strands, and exhibit increased sequence specificity and solubility. The peptide nucleic acids comprise ligands selected from a group consisting...

  13. Biopropionic acid production via molybdenumcatalyzed deoxygenation of lactic acid

    NARCIS (Netherlands)

    Korstanje, T.J.; Kleijn, H.; Jastrzebski, J.T.B.H.; Klein Gebbink, R.J.M.

    2013-01-01

    As the search for non-fossil based building blocks for the chemical industry increases, new methods for the deoxygenation of biomass-derived substrates are required. Here we present the deoxygenation of lactic acid to propionic acid, using a catalyst based on the non-noble and abundant metal

  14. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... Betulinic acid acetate (BAAC) was most effective than other betulinic acid derivatives. It had most ... blastoma (Schmidt et al., 1997), malignant brain tumor .... 96 well plate and incubated in 37oC, 5% CO2 and 90% humidity.

  15. Classifying Your Food as Acid, Low-Acid, or Acidified

    OpenAIRE

    Bacon, Karleigh

    2012-01-01

    As a food entrepreneur, you should be aware of how ingredients in your product make the food look, feel, and taste; as well as how the ingredients create environments for microorganisms like bacteria, yeast, and molds to survive and grow. This guide will help you classifying your food as acid, low-acid, or acidified.

  16. Origin of nucleic acids

    International Nuclear Information System (INIS)

    Prieur, B.E.

    1995-01-01

    The appearance of nucleic acids is the first event after the birth of membranes which made it possible to assure the perenniality of information. The complexity of these molecules has led some scientists to propose that they were not prebiotic but rather derived a more simple and achiral primitive ancestor. This hypothesis suggests that ribose possesses properties that allowed the formation of certain polysaccharides which evolved to RNA. The first step of the hypothesis is the selection and concentration of ribofuranose. This sugar has chelating properties and its alpha-ribofuranose is favoured in the chelating position. The density of the sugar with a heavy cation is greater than water and thus the complex can escape the UV radiation at the surface of the ocean. The particularity of ribose is to be able to form a homochiral regular array of these basic chelating structures with pyrophosphite. These arrays evolve towards the formation of polysaccharides (poly ribose phosphate) which have a very organized structure. These polysaccharides in turn evolve to RNA by binding of adenine and deoxyguanine which are HCN derivatives that can react with the polysaccharides. The primitive RNA is methylated and oxidized to form prebiotic RNA with adenosine, cytidine, 7methyl-guanosine and ribothymidine as nucleic bases. The pathway of biosynthesis of DNA form RNA will be studied. I suggest that the appearance of DNA results form the interaction between prebiotic double stranded RNA and proteins. DNA could be a product of RNA degradation by proteins. The catabolism of RNA to DNA requires a source of free radicals, protons and hydrides. RNA cannot produce free radicals, which are provided by the phenol group of the amino acid tyrosien. Protons are provided by the medium and hydrides are provided by 7-methyl-guanosine which can fix hydrides coming from hydrogen gas and donate them for the transformation of a riboside to a deoxyriboside. This pathway suggests that DNA appeared at

  17. Preparation of fulvic acid and low-molecular organic acids by oxidation of weathered coal humic acid

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, T.; Ito, A.; Sasaki, O.; Yazawa, Y.; Yamaguchi, T. [Chiba Institute of Technolgy, Chiba (Japan). Dept. of Industrial Chemistry

    2002-07-01

    Weathered coal contains much humic acid and a little fulvic acid. Therefore, the production of fulvic acid, the most valuable humic substance because of its water-solubility, was examined by ozone and hydrogen peroxide oxidation of humic acid extracted form Xinjiang (China) weathered coal. The resulting products of the oxidation were water soluble fulvic acid and organic acids, mainly formic acid and oxalic acid. The product yield of fulvic acid was 20 (C%) and that of organic acids were 39 (C%) for formic and acid 13 (C%) for oxalic acid. The formed fulvic acid showed a higher content of oxygen and carboxyl groups, than those of the extracted one from the original weathered coal.

  18. Ascorbic acid in bronchial asthma

    African Journals Online (AJOL)

    1983-04-23

    Apr 23, 1983 ... by comparing the pre-ascorbic acid results with those obtained 21/2 hours after the intravenous ... (ASO), C-reactive protein and antibodies to certain respiratory viruses. These investigations were ..... vitamin.6 However, other investigators were unable to detect any protective effects of ascorbic acid on the ...

  19. Chloroacetic acids in environmental processes

    Czech Academy of Sciences Publication Activity Database

    Matucha, Miroslav; Gryndler, Milan; Forczek, Sándor; Uhlířová, H.; Fuksová, Květoslava; Schröder, P.

    2003-01-01

    Roč. 1, - (2003), s. 127-130 ISSN 1610-3653 R&D Projects: GA ČR GA522/02/0874 Institutional research plan: CEZ:AV0Z5038910 Keywords : Dichloroacetic acid * Trichloroacetic acid * Microbial degradation Subject RIV: GK - Forestry

  20. Acid Rain: An Educational Opportunity?

    Science.gov (United States)

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  1. Bile acids for viral hepatitis

    DEFF Research Database (Denmark)

    Chen, Weikeng; Liu, J; Gluud, C

    2003-01-01

    The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness.......The viral hepatitides are common causes of liver diseases globally. Trials have assessed bile acids for patients with viral hepatitis, but no consensus was reached regarding their usefulness....

  2. Getting Back to Basics (& Acidics)

    Science.gov (United States)

    Rhodes, Sam

    2006-01-01

    This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…

  3. Reactive extraction and recovery of levulinic acid, formic acid and furfural from aqueous solutions containing sulphuric acid

    NARCIS (Netherlands)

    Brouwer, Thomas; Blahusiak, Marek; Babic, Katarina; Schuur, Boelo

    2017-01-01

    Levulinic acid (LA) can be produced from lignocellulosic materials via hydroxylation followed by an acid-catalyzed conversion of hexoses. Inorganic homogeneous catalysts are mostly used, in particular sulphuric acid, yielding a mixture of LA with sulphuric acid, formic acid (FA) and furfural.

  4. Studies on radiolysis of amino acids, (4)

    International Nuclear Information System (INIS)

    Oku, Tadatake

    1978-01-01

    In order to elucidate the effect of adding methionine on the loss of amino acid by γ-irradiation in amino acid mixture, because methionine is one of the most radio-sensitive in amino acids, the remaining amino acids in γ-irradiated aqueous solution of amino acid mixture were studied by determining the total amount of each remaining amino acid. The mixture of 18 amino acids which contains methionine and that of 17 amino acids without methionine were used. Amino acids and the irradiation products were determined with an automatic amino acid analyzer. The total amount of remaining amino acids in the irradiated solution of 18 amino acid mixture was more than that of 17 amino acid mixture. The order of the total amount of each remaining amino acid by low-dose irradiation was Gly>Ala>Asp>Glu>Val>Ser, Pro>Ile, Leu>Thr>Lys>Tyr>Arg>His>Phe>Try>Cys>Met. In case of the comparison of amino acids of same kinds, the total remaining amount of each amino acid in amino acid mixture was more than that of individually irradiated amino acid. The total remaining amounts of glycine, alanine and aspartic acid in irradiated 17 amino acid mixture resulted in slight increase. Ninhydrin positive products formed from 18 amino acid mixture irradiated with 2.640 x 10 3 rad were ammonia, methionine sulfoxide and DOPA of 1.34, 0.001 and 0.25 μmoles/ml of the irradiated solution, respectively. (Kobake, H.)

  5. Valproic Acid-induced Agranulocytosis

    Directory of Open Access Journals (Sweden)

    Hui-Chuan Hsu

    2009-06-01

    Full Text Available Valproic acid is considered to be the most well-tolerated antiepileptic drug. However, few cases of neutropenia or leukopenia caused by valproic acid have been reported. We present a patient who took valproic acid to treat a complication of brain surgery and in whom severe agranulocytosis occurred after 2.5 months. Valproic acid was stopped immediately, and granulocyte colony-stimulating factor was administered for 2 days. The patient's white blood cell count returned to normal within 2 weeks. The result of bone marrow aspiration was compatible with drug-induced agranulocytosis. This case illustrates that patients who take valproic acid may need regular checking of complete blood cell count.

  6. N-(3-Nitrophenylmaleamic acid

    Directory of Open Access Journals (Sweden)

    B. Thimme Gowda

    2010-07-01

    Full Text Available In the title compound, C10H8N2O5, the molecule is slightly distorted from planarity. The molecular structure is stabilized by two intramolecular hydrogen bonds. The first is a short O—H...O hydrogen bond (H...O distance = 1.57 Å within the maleamic acid unit and the second is a C—H...O hydrogen bond (H...O distance = 2.24 Å which connects the amide group with the benzene ring. The nitro group is twisted by 6.2 (2° out of the plane of the benzene ring. The crystal structure manifests a variety of hydrogen bonding. The packing is dominated by a strong intermolecular N—H...O interaction which links the molecules into chains running along the b axis. The chains within a plane are further assembled by three additional types of intermolecular C—H...O hydrogen bonds to form a sheet parallel to the (overline{1}01 plane.

  7. Bioactive phenolic acids from Scorzonera radiata Fisch.

    Directory of Open Access Journals (Sweden)

    N Tsevegsuren

    2014-09-01

    Full Text Available Chromatographic separation of the crude extract obtained from the aerial parts of the Mongolian medicinal plant Scorzonera radiata yielded five new dihydrostilbenes [4], two new flavonoids, one new quinic acid derivative, as well as twenty known compounds including eight quinic acid derivatives, four flavonoids, two coumarins, five simple benzoic acids, and one monoterpene glycoside. We present here results on isolation and structural identification some active phenolic compounds from the Scorzonera radiata - eight quinic acid derivatives (quinic acid, 4,5-dicaffeoylquinic acid, 4,5-dicaffeoyl-epi-quinic acid, 3,5-dicaffeoylquinic acid, 3,5-dicaffeoyl-epi-quinic acid, chlorogenic acid, 5-p-coumaroylquinic acid (trans, 5-p-coumaroylquinic acid (cis. Quinic acid derivatives exhibited antioxidative activity.DOI: http://dx.doi.org/10.5564/mjc.v12i0.177 Mongolian Journal of Chemistry Vol.12 2011: 78-84

  8. Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

    DEFF Research Database (Denmark)

    Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben

    2010-01-01

    Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic...... acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored...

  9. Analytical application of aminohydroxamic acids

    International Nuclear Information System (INIS)

    Fadl Elmoula, Abd ELfatah Abdella

    2000-11-01

    Anthranilic hydroxamic acid was prepared by coupling of methylanthranilate (prepared by esterification of anthranilic acid with methyl alcohol using the fisher-speir method) with freshly prepared hydroxylamine. The lignad was characterized by the usual reaction of hydroxamic acid with acidic V(V) and Fe(III) solutions that gives blood-red colour in amyl alcohol and deep-violet colour in aqueous solution, respectively. The absorbance of Fe(III)-hydroxamic acids complexes increases with increase of pH. In this study, the effect of pH on the absorbance of Fe(III)-anthranilic hydroxamic acid was in accordance with this trend. The maximum absorbance was obtained at pH 5.0 at maximum wavelength of 482 nm. For Cu(II)-anthranilic hydroxamic acid complex, the use of acidic basic pH lead to precipitation of Cu(II)-ligand complex. But when using buffer pH (acetic acid/sodium acetate) a clear green colour of Cu(II)-ligand complex was obtained. The maximum wavelength of 390 nm. V(V)-anthranilic hydroxamic acid complex was extracted in acidic medium in amyl alcohol at pH 2.0 because in aqueous solution V(V)-anthranilic hydroxamic acid complex has not clear colour. It was observed the the maximum extraction in acidic medium decrease sharply with the increasing of pH value. The maximum wavelength for maximum absorbance was recorded at 472 nm. V(V) interfered with determination of Fe(III)) above concentration of 2 ppm, whereas Cu(II) interferes slightly with the determination of Fe(III) ions even at a high concentration of the Cu(II) ions. Both Cu(II) and Ni(II) do not interfere with the determination of V(V) ions even at high concentrations, Fe(III) ion produced slight interference, while Mo(VI) ions have a pronounced interference. Both V(V) and Fe(III) ions interfered markedly with the determination of Cu(II) ions, and made impractical under conditions. However, the calibration curves for the three metal ions produced a practical linear dynamic range.(Author)

  10. Placement of acid spoil materials

    Energy Technology Data Exchange (ETDEWEB)

    Pionke, H B; Rogowski, A S

    1982-06-01

    Potentially there are several chemical and hydrologic problems associated with placement of acid spoil materials. The rationale for a deep placement well below the soil surface, and preferably below a water table, is to prevent or minimize oxidation of pyrite to sulfuric acid and associated salts by reducing the supply of oxygen. If, however, substantial sulfuric acid or associated salts are already contained within the spoil because of present or previous mining, handling and reclamation operations (or if large supplies of indigenous salts exist, placement below a water table) may actually increase the rate of acid and salt leaching. Specific placement of acid- and salt-containing spoil should be aimed at preventing contact with percolating water or rising water tables. We recommend placement based on chemical and physical spoil properties that may affect water percolation O/sub 2/ diffusion rates in the profile. Both the deeper placement of acid spoil and coarser particle size can substantially reduce the amount of acid drainage. Placement above the water table with emphasis on percolate control may be better for high sulfate spoils, while placement below the non-fluctuating water table may be better for pyritic spoils.

  11. Aquatic chemistry of acid deposition

    Energy Technology Data Exchange (ETDEWEB)

    Stumm, W; Sigg, L; Schnoor, J L

    1987-01-01

    The occurrence of acid precipitation in many regions of the Northern hemisphere is a consequnece of human interference in the cycles that unite land, water and atmosphere. The oxidation of carbon, sulfur and nitrogen, resulting mostly from fossil fuel burning, rivals oxidation processes induced by photosynthesis and respiration and disturbs redox conditions in the atmosphere. The paper discusses oxidation-reduction reactions, particularly those involving atmospheric pollutants that are important in the formation of acid precipitation. Topics covered are: a stoichiometric model of acid rain formation; sulfur dioxide and ammonia adsorption; acid neutralizing capacity. The paper concludes that explanations of simple chemical equilibria between gases and water aid our understanding of how acidifying gases become dissolved in cloud water, in droplets of falling rain, or in fog. Rigorous definitions of base- or acid-neutralizing capacities are prerequisites to measuring and interpreting residual acidity in dry and wet deposition and for assessing the disturbance caused by the transfer of acid to terrestrial and aquatic ecosystems. 20 references.

  12. FDG decomposition products

    International Nuclear Information System (INIS)

    Macasek, F.; Buriova, E.

    2004-01-01

    In this presentation authors present the results of analysis of decomposition products of [ 18 ]fluorodexyglucose. It is concluded that the coupling of liquid chromatography - mass spectrometry with electrospray ionisation is a suitable tool for quantitative analysis of FDG radiopharmaceutical, i.e. assay of basic components (FDG, glucose), impurities (Kryptofix) and decomposition products (gluconic and glucuronic acids etc.); 2-[ 18 F]fluoro-deoxyglucose (FDG) is sufficiently stable and resistant towards autoradiolysis; the content of radiochemical impurities (2-[ 18 F]fluoro-gluconic and 2-[ 18 F]fluoro-glucuronic acids in expired FDG did not exceed 1%

  13. catalyzed oxidation of some amino acids by acid bromate

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: Kinetic investigations on Pd(II) catalyzed oxidation of dl-serine and dl- ... A suitable mechanism in agreement with observed kinetics has been ..... In acidic solution of potassium bromate quick .... Annual Review of Biochemistry.

  14. Cytotoxic effect of betulinic acid and betulinic acid acetate isolated ...

    African Journals Online (AJOL)

    GREGORY

    2010-09-20

    Sep 20, 2010 ... Betulinic acid exerts a selective anti-tumor activity on cultured human melanoma .... percentage of proliferation was calculated by the following formula: Proliferation ..... artificially imposing the cell cycle checkpoint. Among.

  15. Influence of fluorozirconic acid on sulfuric acid anodizing of aluminum

    OpenAIRE

    Elaish, R.; Curioni, M.; Gowers, K.; Kasuga, A.; Habazaki, H.; Hashimoto, T.; Skeldon, P.

    2017-01-01

    The effects of additions of fluorozirconic acid to sulfuric acid on the anodizing behavior of aluminum have been investigated under a constant voltage at temperatures of 0 and 20◦C. The fluoroacid increased the rate of film growth, with a dependence on the fluoroacid concentration, the electrolyte temperature and the anodizing time. Compositional analyses showed that fluorine species were present in the films. However, zirconium species were absent. The fluoroacid generally enhanced film diss...

  16. Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes

    International Nuclear Information System (INIS)

    Schick, P.K.; Webster, P.

    1987-01-01

    Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with [ 14 C]-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of [ 14 C]-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of [ 14 C]-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of [ 14 C]-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA

  17. A comparative study of precision cut liver slices, hepatocytes, and liver microsomes from the Wistar rat using metronidazole as a model substance

    DEFF Research Database (Denmark)

    Sidelmann, U. G.; Cornett, Claus; Tjornelund, J.

    1996-01-01

    1. Metronidazole is metabolized by rat liver in vitro models to form a hydroxy metabolite, an acetic acid metabolite, a glucuronic acid conjugate, and a sulphate conjugate. 2. Four different in vitro systems for investigation of drug metabolism based on liver preparations from the male Wistar rat...

  18. Soufy et al., Afr J Tradit Complement Altern Med. (2012) 9(3):389 ...

    African Journals Online (AJOL)

    AJTCAM

    a sweetening and flavoring agent due to its extreme sweetness (Zhang and Ye, 2009). It consists of one molecule of glycyrrhetinic acid and two molecules of glucuronic acid (Mao et al., 2005). It can effectively protect liver against fulminant hepatic failure induced by galactosamine and lipopolysaccharide (Yang et al., 2007).

  19. Untitled

    Indian Academy of Sciences (India)

    been reported by Rao and Beri. Each sugar, it was shown, has a character istic circular R value by the determination of which the sugar can be identi- fied. This method has now been applied for the Separation and identifica- tion of glucuronic and galacturonic acids. These uronic acids, occurring as they do as integral parts ...

  20. Treatment of acid mine wastewaters

    International Nuclear Information System (INIS)

    Hayward, D.; Barnard, R.

    1993-01-01

    Acid mine drainage often results from the oxidation sulfide minerals to form sulfuric acid. As a consequence, high concentrations of metals in the both the suspended and dissolved state result from the low pH water. This paper discusses several of the more common treatment methods for acid mine drainage including the use of chemical precipitation agents, pH correction agents, filtration methods, and biodegradation methods. Advanced treatment technologies are also briefly described and include microfiltration, reverse osmosis, ion exchange, and electrodialysis