WorldWideScience

Sample records for aldehyde oxidizing enzymes

  1. Enzyme-inspired functional surfactant for aerobic oxidation of activated alcohols to aldehydes in water

    KAUST Repository

    Chen, Batian

    2015-02-06

    We describe an enzyme-inspired catalytic system based on a rationally designed multifunctional amphiphile. The resulting micelles feature metal-binding sites and stable free radical moieties as well as fluorous pockets that attract and preconcentrate molecular oxygen. In the presence of copper ions, the micelles effect chemoselective aerobic alcohol oxidation under ambient conditions in water, a transformation that is challenging to achieve nonenzymatically.

  2. The oxidative fermentation of ethanol in Gluconacetobacter diazotrophicus is a two-step pathway catalyzed by a single enzyme: alcohol-aldehyde Dehydrogenase (ADHa).

    Science.gov (United States)

    Gómez-Manzo, Saúl; Escamilla, José E; González-Valdez, Abigail; López-Velázquez, Gabriel; Vanoye-Carlo, América; Marcial-Quino, Jaime; de la Mora-de la Mora, Ignacio; Garcia-Torres, Itzhel; Enríquez-Flores, Sergio; Contreras-Zentella, Martha Lucinda; Arreguín-Espinosa, Roberto; Kroneck, Peter M H; Sosa-Torres, Martha Elena

    2015-01-01

    Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH) and the aldehyde dehydrogenase (ALDH). We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa) of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2-C6) and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde. PMID:25574602

  3. The Oxidative Fermentation of Ethanol in Gluconacetobacter diazotrophicus Is a Two-Step Pathway Catalyzed by a Single Enzyme: Alcohol-Aldehyde Dehydrogenase (ADHa

    Directory of Open Access Journals (Sweden)

    Saúl Gómez-Manzo

    2015-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a N2-fixing bacterium endophyte from sugar cane. The oxidation of ethanol to acetic acid of this organism takes place in the periplasmic space, and this reaction is catalyzed by two membrane-bound enzymes complexes: the alcohol dehydrogenase (ADH and the aldehyde dehydrogenase (ALDH. We present strong evidence showing that the well-known membrane-bound Alcohol dehydrogenase (ADHa of Ga. diazotrophicus is indeed a double function enzyme, which is able to use primary alcohols (C2–C6 and its respective aldehydes as alternate substrates. Moreover, the enzyme utilizes ethanol as a substrate in a reaction mechanism where this is subjected to a two-step oxidation process to produce acetic acid without releasing the acetaldehyde intermediary to the media. Moreover, we propose a mechanism that, under physiological conditions, might permit a massive conversion of ethanol to acetic acid, as usually occurs in the acetic acid bacteria, but without the transient accumulation of the highly toxic acetaldehyde.

  4. Efficient and Highly Aldehyde Selective Wacker Oxidation

    KAUST Repository

    Teo, Peili

    2012-07-06

    A method for efficient and aldehyde-selective Wacker oxidation of aryl-substituted olefins using PdCl 2(MeCN) 2, 1,4-benzoquinone, and t-BuOH in air is described. Up to a 96% yield of aldehyde can be obtained, and up to 99% selectivity can be achieved with styrene-related substrates. © 2012 American Chemical Society.

  5. The oxidation of the aldehyde groups in dialdehyde starch

    NARCIS (Netherlands)

    Haaksman, I.K.; Besemer, A.C.; Jetten, J.M.; Timmermans, J.W.; Slaghek, T.M.

    2006-01-01

    This paper describes the difference in relative reactivity of the aldehyde groups present in dialdehyde starch towards different oxidising agents. The oxidation of dialdehyde starch with peracetic acid and sodium bromide leads to only partial oxidation to give mono-aldehyde-carboxy starch, while oxi

  6. Research advances in the catalysts for the selective oxidation of ethane to aldehydes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; ZHAO Zhen; XU Chunming

    2005-01-01

    Selective oxidation of ethane to aldehydes is one of the most difficult processes in the catalysis researches of low alkanes. The development of selective oxidation of ethane to aldehydes (formaldehyde, acetaldehyde and acrolein) is discussed. The latest progress of the catalysts, including bulk or supported metal oxide catalysts, highly dispersed and isolated active sites catalysts, and the photo-catalytic ethane oxidation catalysts, partial oxidation of ethane in the gas phase, and the proposed reaction pathways from ethane to aldehydes are involved.

  7. Evaluation of alcohol dehydrogenase and aldehyde dehydrogenase enzymes as bi-enzymatic anodes in a membraneless ethanol microfluidic fuel cell

    Science.gov (United States)

    Galindo-de-la-Rosa, J.; Arjona, N.; Arriaga, L. G.; Ledesma-García, J.; Guerra-Balcázar, M.

    2015-12-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (AldH) enzymes were immobilized by covalent binding and used as the anode in a bi-enzymatic membraneless ethanol hybrid microfluidic fuel cell. The purpose of using both enzymes was to optimize the ethanol electro-oxidation reaction (EOR) by using ADH toward its direct oxidation and AldH for the oxidation of aldehydes as by-products of the EOR. For this reason, three enzymatic bioanode configurations were evaluated according with the location of enzymes: combined, vertical and horizontally separated. In the combined configuration, a current density of 16.3 mA cm-2, a voltage of 1.14 V and a power density of 7.02 mW cm-2 were obtained. When enzymes were separately placed in a horizontal and vertical position the ocp drops to 0.94 V and to 0.68 V, respectively. The current density also falls to values of 13.63 and 5.05 mA cm-2. The decrease of cell performance of bioanodes with separated enzymes compared with the combined bioanode was of 31.7% and 86.87% for the horizontal and the vertical array.

  8. Oxidation of N-alkyl and N-aryl azaheterocycles by free and immobilized rabbit liver aldehyde oxidase

    NARCIS (Netherlands)

    Angelino, S.A.G.F.

    1984-01-01

    Aldehyde oxidase isolated from rabbit liver is studied in this thesis with regard to its application in organic synthesis. The enzyme has a broad substrate specificity towards azaheterocycles and therefore offers great potential for profitable use.The oxidation of 1-alkyl(aryl)-3-aminocarbonylpyridi

  9. On the role of long-chain aldehydes in the light reaction in Photobacterium phosphoreum enzyme preparations

    NARCIS (Netherlands)

    Terpstra, Willemke

    1960-01-01

    1. (1) Active luciferase-DPNH-oxidase preparations from Photobacterium phosphoreum generally contain some aldehyde-attacking enzyme, probably ADH. Under the experimental conditions applied this enzyme appears to attack decanal, but not palmital. 2. (2) The presence of long-chain aldehydes in the en

  10. Release and Formation of Oxidation-Related Aldehydes during Wine Oxidation.

    Science.gov (United States)

    Bueno, Mónica; Carrascón, Vanesa; Ferreira, Vicente

    2016-01-27

    Twenty-four Spanish wines were subjected to five consecutive cycles of air saturation at 25 °C. Free and bound forms of carbonyls were measured in the initial samples and after each saturation. Nonoxidized commercial wines contain important and sensory relevant amounts of oxidation-related carbonyls under the form of odorless bound forms. Models relating the contents in total aldehydes to the wine chemical composition suggest that fermentation can be a major origin for Strecker aldehydes: methional, phenylacetaldehyde, isobutyraldehyde, 2-methylbutanal, and isovaleraldehyde. Bound forms are further cleaved, releasing free aldehydes during the first steps of wine oxidation, as a consequence of equilibrium shifts caused by the depletion of SO2. At low levels of free SO2, de novo formation and aldehyde degradation are both observed. The relative importance of these phenomena depends on both the aldehyde and the wine. Models relating aldehyde formation rates to wine chemical composition suggest that amino acids are in most cases the most important precursors for de novo formation.

  11. Catalytic Fehling's Reaction: An Efficient Aerobic Oxidation of Aldehyde Catalyzed by Copper in Water.

    Science.gov (United States)

    Liu, Mingxin; Li, Chao-Jun

    2016-08-26

    The first example of homogeneous copper-catalyzed aerobic oxidation of aldehydes is reported. This method utilizes atmospheric oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification. PMID:27505714

  12. Oxidative desulfurization of diesel with TBHP/isobutyl aldehyde/air oxidation system

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei; Wang, Chengyong; Lin, Peng; Lu, Xiaoping [Institute of Sonochemical Engineering, Nanjing University of Technology, Nanjing 210009, Jiangsu (China)

    2011-01-15

    Oxidative desulfurization of hydrogenation diesel (40 mL) was studied using air as oxidant, tert-butyl hydroperoxide (TBHP) as radical initiator at ambient pressure and moderate temperature in the presence of isobutyl aldehyde. TBHP could accelerate the production of carbonyl radical and its peroxidation. When the molar fraction of TBHP was 5 mmol, the conversion of DBT could reach 96.1% in the present of 20 mmol isobutyl aldehyde and air, which was more than that of 85.5% without initiator. The air was an effective oxidant and acetonitrile was an optimal solvent in this process. The sulfur content of the hydrogenation diesel could be reduced from 403 to 13 ppm (96.8% removed) under the synergistic effect of air, TBHP and isobutyl aldehyde. (author)

  13. The carbonyl oxide-aldehyde complex: a new intermediate of the ozonolysis reaction

    Science.gov (United States)

    Cremer, Dieter; Kraka, Elfi; McKee, M. L.; Radharkrishnan, T. P.

    1991-12-01

    MP4(SDQ)/6-31G (d,p) calculations suggest that the ozonolysis of alkenes in solution phase does not proceed via carbonyl oxide, but via a dipole complex between aldehyde and carbonyl oxide, which is 9 kcal/mol more stable than the separated molecules. The dipole complex is probably formed in the solvent cage upon decomposition of primary ozonide to aldehyde and carbonyl oxide. Rotation of either aldehyde or carbonyl oxide in the solvent cage leads to an antiparallel alignment of molecular dipole moments and dipole-dipole attraction.

  14. Modelling of the partial oxidation of {alpha}, {beta}-unsaturated aldehydes on Mo-V-oxides based catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Boehnke, H.; Petzoldt, J.C.; Stein, B.; Weimer, C.; Gaube, J.W. [Technische Univ. Darmstadt (Germany). Inst. fuer Chemische Technologie

    1998-12-31

    A kinetic model based on the Mars-van Krevelen mechanism that allows to describe the microkinetics of the heterogeneously catalysed partial oxidation of {alpha}, {beta}-unsaturated aldehydes is presented. This conversion is represented by a network, composed of the oxidation of the {alpha}, {beta}-unsaturated aldehyde towards the {alpha}, {beta}-unsaturated carboxylic acid and the consecutive oxidation of the acid as well as the parallel reaction of the aldehyde to products of deeper oxidation. The reaction steps of aldehyde respectively acid oxidation and catalyst reoxidation have been investigated separately in transient experiments. The combination of steady state and transient experiments has led to an improved understanding of the interaction of the catalyst with the aldehyde and the carboxylic acids as well as to a support of the kinetic model assumptions. (orig.)

  15. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    Science.gov (United States)

    Smith, R.E.; Dolbeare, F.A.

    1980-10-21

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 4-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes. No Drawings

  16. Fluorescence method for enzyme analysis which couples aromatic amines with aromatic aldehydes

    Science.gov (United States)

    Smith, Robert E.; Dolbeare, Frank A.

    1979-01-01

    Analysis of proteinases is accomplished using conventional amino acid containing aromatic amine substrates. Aromatic amines such as 4-methoxy-2-naphthylamine (4M2NA), 2-naphthylamine, aminoisophthalic acid dimethyl ester, p-nitroaniline, 5-methoxy-1-aminofluorene and coumarin derivatives resulting from enzymatic hydrolysis of the substrate couples with aromatic aldehydes such as 5-nitrosalicylaldehyde (5-NSA), benzaldehyde and p-nitrobenzaldehyde to produce Schiff-base complexes which are water insoluble. Certain Schiff-base complexes produce a shift from blue to orange-red (visible) fluorescence. Such complexes are useful in the assay of enzymes.

  17. MOLECULAR MODELLING OF HUMAN ALDEHYDE OXIDASE AND IDENTIFICATION OF THE KEY INTERACTIONS IN THE ENZYME-SUBSTRATE COMPLEX

    Directory of Open Access Journals (Sweden)

    Siavoush Dastmalchi

    2005-05-01

    Full Text Available Aldehyde oxidase (EC 1.2.3.1, a cytosolic enzyme containing FAD, molybdenum and iron-sulphur cluster, is a member of non-cytochrome P-450 enzymes called molybdenum hydroxylases which is involved in the metabolism of a wide range of endogenous compounds and many drug substances. Drug metabolism is one of the important characteristics which influences many aspects of a therapeutic agent such as routes of administration, drug interaction and toxicity and therefore, characterisation of the key interactions between enzymes and substrates is very important from drug development point of view. The aim of this study was to generate a three-dimensional model of human aldehyde oxidase (AO in order to assist us to identify the mode of interaction between enzyme and a set of phethalazine/quinazoline derivatives. Both sequence-based (BLAST and inverse protein fold recognition methods (THREADER were used to identify the crystal structure of bovine xanthine dehydrogenase (pdb code of 1FO4 as the suitable template for comparative modelling of human AO. Model structure was generated by aligning and then threading the sequence of human AO onto the template structure, incorporating the associated cofactors, and molecular dynamics simulations and energy minimization using GROMACS program. Different criteria which were measured by the PROCHECK, QPACK, VERIFY-3D were indicative of a proper fold for the predicted structural model of human AO. For example, 97.9 percentages of phi and psi angles were in the favoured and most favoured regions in the ramachandran plot, and all residues in the model are assigned environmentally positive compatibility scores. Further evaluation on the model quality was performed by investigation of AO-mediated oxidation of a set of phthalazine/quinazoline derivatives to develop QSAR model capable of describing the extent of the oxidation. Substrates were aligned by docking onto the active site of the enzyme using GOLD technology and then

  18. Oxidation of Group 8 transition-Metal Hydrides and Ionic Hydrogenation of Ketones and Aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Kjell-Tore

    1996-08-01

    Transition-metal hydrides have received considerable attention during the last decades because of their unusual reactivity and their potential as homogeneous catalysts for hydrogenation and other reactions of organic substrates. An important class of catalytic processes where transition-metal hydrides are involved is the homogeneous hydrogenation of alkenes, alkynes, ketones, aldehydes, arenes and nitro compounds. This thesis studies the oxidation of Group 8 transition-metal hydrides and the ionic hydrogenation of ketones and aldehydes.

  19. Aerobic oxidation of aldehydes under ambient conditions using supported gold nanoparticle catalysts

    DEFF Research Database (Denmark)

    Marsden, Charlotte Clare; Taarning, Esben; Hansen, David;

    2008-01-01

    A new, green protocol for producing simple esters by selectively oxidizing an aldehyde dissolved in a primary alcohol has been established, utilising air as the oxidant and supported gold nanoparticles as catalyst. The oxidative esterifications proceed with excellent selectivities at ambient cond...... conditions; the reactions can be performed in an open flask and at room temperature. Benzaldehyde is even oxidised at a reasonable rate below -70 degrees C. Acrolein is oxidised to methyl acrylate in high yield using the same protocol....

  20. Aldehyde-Selective Wacker-Type Oxidation of Unbiased Alkenes Enabled by a Nitrite Co-Catalyst

    KAUST Repository

    Wickens, Zachary K.

    2013-09-13

    Breaking the rules: Reversal of the high Markovnikov selectivity of Wacker-type oxidations was accomplished using a nitrite co-catalyst. Unbiased aliphatic alkenes can be oxidized with high yield and aldehyde selectivity, and several functional groups are tolerated. 18O-labeling experiments indicate that the aldehydic O atom is derived from the nitrite salt.

  1. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    International Nuclear Information System (INIS)

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H2O2) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS4)) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS4). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS4)/H2O2 was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS4)/H2O2 system

  2. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

    Directory of Open Access Journals (Sweden)

    Giovanna Romano

    Full Text Available Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms.

  3. Nitric oxide mediates the stress response induced by diatom aldehydes in the sea urchin Paracentrotus lividus.

    Science.gov (United States)

    Romano, Giovanna; Costantini, Maria; Buttino, Isabella; Ianora, Adrianna; Palumbo, Anna

    2011-01-01

    Diatoms are ubiquitous and abundant primary producers that have been traditionally considered as a beneficial food source for grazers and for the transfer of carbon through marine food webs. However, many diatom species produce polyunsaturated aldehydes that disrupt development in the offspring of grazers that feed on these unicellular algae. Here we provide evidence that production of the physiological messenger nitric oxide increases after treatment with the polyunsaturated aldehyde decadienal in embryos of the sea urchin Paracentrotus lividus. At high decadienal concentrations, nitric oxide mediates initial apoptotic events leading to loss of mitochondrial functionality through the generation of peroxynitrite. At low decadienal concentrations, nitric oxide contributes to the activation of hsp70 gene expression thereby protecting embryos against the toxic effects of this aldehyde. When nitric oxide levels were lowered by inhibiting nitric oxide synthase activity, the expression of hsp70 in swimming blastula decreased and the proportion of abnormal plutei increased. However, in later pluteus stages nitric oxide was no longer able to exert this protective function: hsp70 and nitric oxide synthase expression decreased with a consequent increase in the expression of caspase-8. Our findings that nitric oxide production increases rapidly in response to a toxic exogenous stimulus opens new perspectives on the possible role of this gas as an important messenger to environmental stress in sea urchins and for understanding the cellular mechanisms underlying toxicity during diatom blooms. PMID:22022485

  4. Size-Selective Oxidation of Aldehydes with Zeolite Encapsulated Gold Nanoparticles

    DEFF Research Database (Denmark)

    Højholt, Karen Thrane; Laursen, Anders Bo; Kegnæs, Søren;

    2011-01-01

    Here, we report a synthesis and catalytic study of hybrid materials comprised of 1–3 nm sinter-stable Au nanoparticles in MFI-type zeolites. An optional post-treatment in aqua regia effectively remove Au from the external surfaces. The size-selective aerobic aldehyde oxidation verifies...

  5. Mitochondrial aldehyde dehydrogenase 2 protects gastric mucosa cells against DNA damage caused by oxidative stress.

    Science.gov (United States)

    Duan, Yantao; Gao, Yaohui; Zhang, Jun; Chen, Yinan; Jiang, Yannan; Ji, Jun; Zhang, Jianian; Chen, Xuehua; Yang, Qiumeng; Su, Liping; Zhang, Jun; Liu, Bingya; Zhu, Zhenggang; Wang, Lishun; Yu, Yingyan

    2016-04-01

    Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is a member of the aldehyde dehydrogenase superfamily and is involved with the metabolic processing of aldehydes. ALDH2 plays a cytoprotective role by removing aldehydes produced during normal metabolism. We examined the cytoprotective role of ALDH2 specifically in gastric mucosa cells. Overexpression of ALDH2 increased the viability of gastric mucosa cells treated with H2O2, while knockdown of ALDH2 had an opposite effect. Moreover, overexpression of ALDH2 protected gastric mucosa cells against oxidative stress-induced apoptosis as determined by flow cytometry, Hoechst 33342, and TUNEL assays. Consistently, ALDH2 knockdown had an opposite effect. Additionally, DNA damage was ameliorated in ALDH2-overexpressing gastric mucosa cells treated with H2O2. We further identified that this cytoprotective role of ALDH2 was mediated by metabolism of 4-hydroxynonenal (4-HNE). Consistently, 4-HNE mimicked the oxidative stress induced by H2O2 in gastric mucosa cells. Treatment with 4-HNE increased levels of DNA damage in ALDH2-knockdown GES-1 cells, while overexpression of ALDH2 decreased 4-HNE-induced DNA damage. These findings suggest that ALDH2 can protect gastric mucosa cells against DNA damage caused by oxidative stress by reducing levels of 4-HNE.

  6. Pulsed corona discharge oxidation of aqueous lignin: decomposition and aldehydes formation.

    Science.gov (United States)

    Panorel, Iris; Kaijanen, Laura; Kornev, Iakov; Preis, Sergei; Louhi-Kultanen, Marjatta; Sirén, Heli

    2014-01-01

    Lignin is the mass waste product of pulp and paper industry mostly incinerated for energy recovery. Lignin is, however, a substantial source of raw material for derivatives currently produced in costly wet oxidation processes. The pulsed corona discharge (PCD) for the first time was applied to lignin oxidation aiming a cost-effective environmentally friendly lignin removal and transformation to aldehydes. The experimental research into treatment of coniferous kraft lignin aqueous solutions was undertaken to establish the dependence of lignin oxidation and aldehyde formation on the discharge parameters, initial concentration of lignin and gas phase composition. The rate and the energy efficiency of lignin oxidation increased with increasing oxygen concentration reaching up to 82 g kW-1 h-1 in 89% vol. oxygen. Oxidation energy efficiency in PCD treatment exceeds the one for conventional ozonation by the factor of two under the experimental conditions. Oxidation at low oxygen concentrations showed a tendency of the increasing aldehydes and glyoxylic acid formation yield. PMID:24600854

  7. Mesenchymal Stem/Stromal Cells Derived From a Reproductive Tissue Niche Under Oxidative Stress Have High Aldehyde Dehydrogenase Activity.

    Science.gov (United States)

    Kusuma, Gina D; Abumaree, Mohamed H; Pertile, Mark D; Perkins, Anthony V; Brennecke, Shaun P; Kalionis, Bill

    2016-06-01

    The use of mesenchymal stem/stromal cells (MSC) in regenerative medicine often requires MSC to function in environments of high oxidative stress. Human pregnancy is a condition where the mother's tissues, and in particular her circulatory system, are exposed to increased levels of oxidative stress. MSC in the maternal decidua basalis (DMSC) are in a vascular niche, and thus would be exposed to oxidative stress products in the maternal circulation. Aldehyde dehydrogenases (ALDH) are a large family of enzymes which detoxify aldehydes and thereby protect stem cells against oxidative damage. A subpopulation of MSC express high levels of ALDH (ALDH(br)) and these are more potent in repairing and regenerating tissues. DMSC was compared with chorionic villous MSC (CMSC) derived from the human placenta. CMSC reside in vascular niche and are exposed to the fetal circulation, which is in lower oxidative state. We screened an ALDH isozyme cDNA array and determined that relative to CMSC, DMSC expressed high levels of ALDH1 family members, predominantly ALDH1A1. Immunocytochemistry gave qualitative confirmation at the protein level. Immunofluorescence detected ALDH1 immunoreactivity in the DMSC and CMSC vascular niche. The percentage of ALDH(br) cells was calculated by Aldefluor assay and DMSC showed a significantly higher percentage of ALDH(br) cells than CMSC. Finally, flow sorted ALDH(br) cells were functionally potent in colony forming unit assays. DMSC, which are derived from pregnancy tissues that are naturally exposed to high levels of oxidative stress, may be better candidates for regenerative therapies where MSC must function in high oxidative stress environments. PMID:26880140

  8. Aldehyde Selective Wacker Oxidations of Phthalimide Protected Allylic Amines : A New Catalytic Route to beta(3)-Amino Acids

    NARCIS (Netherlands)

    Weiner, Barbara; Baeza Garcia, Alejandro; Jerphagnon, Thomas; Feringa, Ben L.

    2009-01-01

    A new method for the synthesis of B-3-amino acids is presented. Phthalimide protected allylic amines are oxidized under Wacker conditions selectively to aldehydes using PdCl2 and CuCl or Pd(MeCN)(2)Cl(NO2) and CuCl2 as complementary catalyst systems. The aldehydes are produced in excellent yields an

  9. Cellulose degradation by oxidative enzymes

    Directory of Open Access Journals (Sweden)

    Maria Dimarogona

    2012-09-01

    Full Text Available Enzymatic degradation of plant biomass has attracted intensive research interest for the production of economically viable biofuels. Here we present an overview of the recent findings on biocatalysts implicated in the oxidative cleavage of cellulose, including polysaccharide monooxygenases (PMOs or LPMOs which stands for lytic PMOs, cellobiose dehydrogenases (CDHs and members of carbohydrate-binding module family 33 (CBM33. PMOs, a novel class of enzymes previously termed GH61s, boost the efficiency of common cellulases resulting in increased hydrolysis yields while lowering the protein loading needed. They act on the crystalline part of cellulose by generating oxidized and non-oxidized chain ends. An external electron donor is required for boosting the activity of PMOs. We discuss recent findings concerning their mechanism of action and identify issues and questions to be addressed in the future.

  10. Selective Production of Aromatic Aldehydes from Heavy Fraction of Bio-oil via Catalytic Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yan; Chang, Jie; Ouyang, Yong; Zheng, Xianwei [South China Univ. of Technology, Guangzhou (China)

    2014-06-15

    High value-added aromatic aldehydes (e. g. vanillin and syringaldehyde) were produced from heavy fraction of bio-oil (HFBO) via catalytic oxidation. The concept is based on the use of metalloporphyin as catalyst and hydrogen peroxide (H{sub 2}O{sub 2}) as oxidant under alkaline condition. The biomimetic catalyst cobalt(II)-sulfonated tetraphenylporphyrin (Co(TPPS{sub 4})) was prepared and characterized. It exhibited relative high activity in the catalytic oxidation of HFBO. 4.57 wt % vanillin and 1.58 wt % syringaldehyde were obtained from catalytic oxidation of HFBO, compared to 2.6 wt % vanillin and 0.86 wt % syringaldehyde without Co(TPPS{sub 4}). Moreover, a possible mechanism of HFBO oxidation using Co(TPPS{sub 4})/H{sub 2}O{sub 2} was proposed by the research of model compounds. The results showed that this is a promising and environmentally friendly method for production of aromatic aldehydes from HFBO under Co(TPPS{sub 4})/H{sub 2}O{sub 2} system.

  11. Molecular cloning of a plant betaine-aldehyde dehydrogenase, an enzyme implicated in adaptation to salinity and drought.

    OpenAIRE

    Weretilnyk, E A; Hanson, A D

    1990-01-01

    Many plants, as well as other organisms, accumulate betaine (N,N,N-trimethylglycine) as a nontoxic or protective osmolyte under saline or dry conditions. In plants, the last step in betaine synthesis is catalyzed by betaine-aldehyde dehydrogenase (BADH, EC 1.2.1.8), a nuclear-encoded chloroplastic enzyme. A cDNA clone for BADH (1812 base pairs) was selected from a lambda gt10 cDNA library derived from leaves of salt-stressed spinach (Spinacia oleracea L.). The library was screened with oligon...

  12. Going Beyond Common Drug Metabolizing Enzymes: Case Studies of Biotransformation Involving Aldehyde Oxidase, γ-Glutamyl Transpeptidase, Cathepsin B, Flavin-Containing Monooxygenase, and ADP-Ribosyltransferase.

    Science.gov (United States)

    Fan, Peter W; Zhang, Donglu; Halladay, Jason S; Driscoll, James P; Khojasteh, S Cyrus

    2016-08-01

    The significant roles that cytochrome P450 (P450) and UDP-glucuronosyl transferase (UGT) enzymes play in drug discovery cannot be ignored, and these enzyme systems are commonly examined during drug optimization using liver microsomes or hepatocytes. At the same time, other drug-metabolizing enzymes have a role in the metabolism of drugs and can lead to challenges in drug optimization that could be mitigated if the contributions of these enzymes were better understood. We present examples (mostly from Genentech) of five different non-P450 and non-UGT enzymes that contribute to the metabolic clearance or bioactivation of drugs and drug candidates. Aldehyde oxidase mediates a unique amide hydrolysis of GDC-0834 (N-[3-[6-[4-[(2R)-1,4-dimethyl-3-oxopiperazin-2-yl]anilino]-4-methyl-5-oxopyrazin-2-yl]-2-methylphenyl]-4,5,6,7-tetrahydro-1-benzothiophene-2-carboxamide), leading to high clearance of the drug. Likewise, the rodent-specific ribose conjugation by ADP-ribosyltransferase leads to high clearance of an interleukin-2-inducible T-cell kinase inhibitor. Metabolic reactions by flavin-containing monooxygenases (FMO) are easily mistaken for P450-mediated metabolism such as oxidative defluorination of 4-fluoro-N-methylaniline by FMO. Gamma-glutamyl transpeptidase is involved in the initial hydrolysis of glutathione metabolites, leading to formation of proximate toxins and nephrotoxicity, as is observed with cisplatin in the clinic, or renal toxicity, as is observed with efavirenz in rodents. Finally, cathepsin B is a lysosomal enzyme that is highly expressed in human tumors and has been targeted to release potent cytotoxins, as in the case of brentuximab vedotin. These examples of non-P450- and non-UGT-mediated metabolism show that a more complete understanding of drug metabolizing enzymes allows for better insight into the fate of drugs and improved design strategies of molecules in drug discovery. PMID:27117704

  13. Oxidation of N-Nitrosoalkylamines by human cytochrome P450 2A6: sequential oxidation to aldehydes and carboxylic acids and analysis of reaction steps.

    Science.gov (United States)

    Chowdhury, Goutam; Calcutt, M Wade; Guengerich, F Peter

    2010-03-12

    Cytochrome P450 (P450) 2A6 activates nitrosamines, including N,N-dimethylnitrosamine (DMN) and N,N-diethylnitrosamine (DEN), to alkyl diazohydroxides (which are DNA-alkylating agents) and also aldehydes (HCHO from DMN and CH(3)CHO from DEN). The N-dealkylation of DMN had a high intrinsic kinetic deuterium isotope effect ((D)k(app) approximately 10), which was highly expressed in a variety of competitive and non-competitive experiments. The (D)k(app) for DEN was approximately 3 and not expressed in non-competitive experiments. DMN and DEN were also oxidized to HCO(2)H and CH(3)CO(2)H, respectively. In neither case was a lag observed, which was unexpected considering the k(cat) and K(m) parameters measured for oxidation of DMN and DEN to the aldehydes and for oxidation of the aldehydes to the carboxylic acids. Spectral analysis did not indicate strong affinity of the aldehydes for P450 2A6, but pulse-chase experiments showed only limited exchange with added (unlabeled) aldehydes in the oxidations of DMN and DEN to carboxylic acids. Substoichiometric kinetic bursts were observed in the pre-steady-state oxidations of DMN and DEN to aldehydes. A minimal kinetic model was developed that was consistent with all of the observed phenomena and involves a conformational change of P450 2A6 following substrate binding, equilibrium of the P450-substrate complex with a non-productive form, and oxidation of the aldehydes to carboxylic acids in a process that avoids relaxation of the conformation following the first oxidation (i.e. of DMN or DEN to an aldehyde). PMID:20061389

  14. Molecular cloning of a plant betaine-aldehyde dehydrogenase, an enzyme implicated in adaptation to salinity and drought

    International Nuclear Information System (INIS)

    Many plants, as well as other organisms, accumulate betaine (N,N,N-trimethylglycine) as a nontoxic or protective osmolyte under saline or dry conditions. In plants, the last step in betaine synthesis is catalyzed by betaine-aldehyde dehydrogenase, a nuclear-encoded chloroplastic enzyme. A cDNA clone for BADH (1812 base pairs) was selected from a λgt10 cDNA library derived from leaves of salt-stressed spinach (Spinacia oleracea L.). The library was screened with oligonucleotide probes corresponding to amino acid sequences of two peptides prepared from purified BADH. The authenticity of the clone was confirmed by nucleotide sequence analysis; this analysis demonstrated the presence of a 1491-base-pair open reading frame that contained sequences encoding 12 peptide fragments of BADH. The clone hybridized to a 1.9-kilobase mRNA from spinach leaves; this mRNA was more abundant in salt-stressed plants, consistent with the known salt induction of BADH activity. The amino acid sequence deduced for the BADH cDNA sequence showed substantial similarities to those for nonspecific aldehyde dehydrogenases from several sources, including absolute conservation of a decapeptide in the probable active site. Comparison of deduced and determined amino acid sequences indicated that the transit peptide may comprise only 7 or 8 residues, which is atypically short for precursors to stromal proteins

  15. Molecular cloning of a plant betaine-aldehyde dehydrogenase, an enzyme implicated in adaptation to salinity and drought.

    Science.gov (United States)

    Weretilnyk, E A; Hanson, A D

    1990-04-01

    Many plants, as well as other organisms, accumulate betaine (N,N,N-trimethylglycine) as a nontoxic or protective osmolyte under saline or dry conditions. In plants, the last step in betaine synthesis is catalyzed by betaine-aldehyde dehydrogenase (BADH, EC 1.2.1.8), a nuclear-encoded chloroplastic enzyme. A cDNA clone for BADH (1812 base pairs) was selected from a lambda gt10 cDNA library derived from leaves of salt-stressed spinach (Spinacia oleracea L.). The library was screened with oligonucleotide probes corresponding to amino acid sequences of two peptides prepared from purified BADH. The authenticity of the clone was confirmed by nucleotide sequence analysis; this analysis demonstrated the presence of a 1491-base-pair open reading frame that contained sequences encoding 12 peptide fragments of BADH. The clone hybridized to a 1.9-kilobase mRNA from spinach leaves; this mRNA was more abundant in salt-stressed plants, consistent with the known salt induction of BADH activity. The amino acid sequence deduced from the BADH cDNA sequence showed substantial similarities to those for nonspecific aldehyde dehydrogenases (EC 1.2.1.3 and EC 1.2.1.5) from several sources, including absolute conservation of a decapeptide in the probable active site. Comparison of deduced and determined amino acid sequences indicated that the transit peptide may comprise only 7 or 8 residues, which is atypically short for precursors to stromal proteins. PMID:2320587

  16. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    Directory of Open Access Journals (Sweden)

    Sales F.G.

    2004-01-01

    Full Text Available In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM applied to the liquid phase.

  17. Self-assembled monolayers of 1-alkenes on oxidized platinum surfaces as platforms for immobilized enzymes for biosensing

    NARCIS (Netherlands)

    Alonso, Jose Maria; Bielen, Abraham A.M.; Olthuis, Wouter; Kengen, Servé W.M.; Zuilhof, Han; Franssen, Maurice C.R.

    2016-01-01

    Alkene-based self-assembled monolayers grafted on oxidized Pt surfaces were used as a scaffold to covalently immobilize oxidase enzymes, with the aim to develop an amperometric biosensor platform. NH2-terminated organic layers were functionalized with either aldehyde (CHO) or N-hydroxy

  18. Self-assembled monolayers of 1-alkenes on oxidized platinum surfaces as platforms for immobilized enzymes for biosensing

    NARCIS (Netherlands)

    Aznar Alonso, J.M.; Bielen, A.A.M; Olthuis, W.; Kengen, S.W.M; Zuilhof, H.; Franssen, M.

    2016-01-01

    Alkene-based self-assembled monolayers grafted on oxidized Pt surfaces were used as a scaffold to covalently immobilize oxidase enzymes, with the aim to develop an amperometric biosensor platform. NH2-terminated organic layers were functionalized with either aldehyde (CHO) or N-hydroxysuccinimide (N

  19. [Effects of panthenol and carnitine on aldehyde metabolic enzymes in rats with tetrachloromethane-induced liver injury].

    Science.gov (United States)

    Satanovskaia, V I; Pron'ko, P S; Gaĭshmanova, A V; Miskevich, D A

    2009-01-01

    Tetrachloromethane (2 g/kg, intragastric) produced a decrease in the activity of NAD- and NADH- dependent aldehyde dehydrogenases with high Km for aldehydes in rat liver. Panthenol and L-carnitine administered separately normalized the activity of aldehyde dehydrogenases, while a combination of the drugs did not produce any significant effect. PMID:19441727

  20. Pyruvate:ferredoxin oxidoreductase and bifunctional aldehyde-alcohol dehydrogenase are essential for energy metabolism under oxidative stress in Entamoeba histolytica.

    Science.gov (United States)

    Pineda, Erika; Encalada, Rusely; Rodríguez-Zavala, José S; Olivos-García, Alfonso; Moreno-Sánchez, Rafael; Saavedra, Emma

    2010-08-01

    The in vitro Entamoeba histolytica pyruvate:ferredoxin oxidoreductase (EhPFOR) kinetic properties and the effect of oxidative stress on glycolytic pathway enzymes and fluxes in live trophozoites were evaluated. EhPFOR showed a strong preference for pyruvate as substrate over other oxoacids. The enzyme was irreversibly inactivated by a long period of saturating O(2) exposure (IC(50) 0.034 mm), whereas short-term exposure ( 90% inhibition allowed for partial restoration by addition of Fe(2+). CoA and acetyl-CoA prevented, whereas pyruvate exacerbated, inactivation induced by short-term saturating O(2) exposure. Superoxide dismutase was more effective than catalase in preventing the inactivation, indicating that reactive oxygen species (ROS) were involved. Hydrogen peroxide caused inactivation in an Fe(2+)-reversible fashion that was not prevented by the coenzymes, suggesting different mechanisms of enzyme inactivation by ROS. Structural analysis on an EhPFOR 3D model suggested that the protection against ROS provided by coenzymes could be attributable to their proximity to the Fe-S clusters. After O(2) exposure, live parasites displayed decreased enzyme activities only for PFOR (90%) and aldehyde dehydrogenase (ALDH; 68%) of the bifunctional aldehyde-alcohol dehydrogenase (EhADH2), whereas acetyl-CoA synthetase remained unchanged, explaining the increased acetate and lowered ethanol fluxes. Remarkably, PFOR and ALDH activities were restored after return of the parasites to normoxic conditions, which correlated with higher ethanol and lower acetate fluxes. These results identified amebal PFOR and ALDH of EhADH2 activities as markers of oxidative stress, and outlined their relevance as significant controlling steps of energy metabolism in parasites subjected to oxidative stress. PMID:20629749

  1. Aerobic oxidation of benzylic aldehydes to acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride under ambient conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetraphenylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed. The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.

  2. Isolation of an Aldehyde Dehydrogenase Involved in the Oxidation of Fluoroacetaldehyde to Fluoroacetate in Streptomyces cattleya

    Science.gov (United States)

    Murphy, Cormac D.; Moss, Steven J.; O'Hagan, David

    2001-01-01

    Streptomyces cattleya is unusual in that it produces fluoroacetate and 4-fluorothreonine as secondary metabolites. We now report the isolation of an NAD+-dependent fluoroacetaldehyde dehydrogenase from S. cattleya that mediates the oxidation of fluoroacetaldehyde to fluoroacetate. This is the first enzyme to be identified that is directly involved in fluorometabolite biosynthesis. Production of the enzyme begins in late exponential growth and continues into the stationary phase. Measurement of kinetic parameters shows that the enzyme has a high affinity for fluoroacetaldehyde and glycoaldehyde, but not acetaldehyde. PMID:11571203

  3. cDNA cloning and analysis of betaine aldehyde dehydrogenase, a salt inducible enzyme in sugar beet

    Energy Technology Data Exchange (ETDEWEB)

    McCue, K.F.; Hanson, A.D. (Michigan State Univ., East Lansing (USA))

    1990-05-01

    Betaine accumulates and serves as a compatible osmolyte in some plants subjected to drought or salinity stress. The last enzyme in the betaine biosynthetic pathway is betaine aldehyde dehydrogenase (BADH). The activity of BADH increases in response to increasing salinity levels. This increase in activity corresponds to an increase in protein detectable by immunoblotting, and to an increase in the translatable BADH mRNA. BADH was cloned from a cDNA library constructed in {lambda}gt10 using poly(A){sup +} RNA from sugar beets salinized to 500 mM NaCl. cDNAs were size selected (>1kb) before ligation into the vector, and the library was screened with a spinach BADH cDNA probe. Three nearly full length clones obtained were confirmed as BADH by their nucleotide and deduced amino acid homology to spinach BADH. Clones averaged 1.8 kb and contained open reading frames of 500 amino acids at 80% identity with spinach BADH. RNA gel blot analysis of poly(A){sup +} RNA indicated that salinization to 500 mM NaCl resulted in a 5-fold increase of BADH mRNA level.

  4. One-pot synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines using supported gold and base as catalysts

    DEFF Research Database (Denmark)

    Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie;

    2012-01-01

    Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol.......Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol....

  5. Aldehyde sources, metabolism, molecular toxicity mechanisms, and possible effects on human health.

    Science.gov (United States)

    O'Brien, Peter J; Siraki, Arno G; Shangari, Nandita

    2005-08-01

    Aldehydes are organic compounds that are widespread in nature. They can be formed endogenously by lipid peroxidation (LPO), carbohydrate or metabolism ascorbate autoxidation, amine oxidases, cytochrome P-450s, or myeloperoxidase-catalyzed metabolic activation. This review compares the reactivity of many aldehydes towards biomolecules particularly macromolecules. Furthermore, it includes not only aldehydes of environmental or occupational concerns but also dietary aldehydes and aldehydes formed endogenously by intermediary metabolism. Drugs that are aldehydes or form reactive aldehyde metabolites that cause side-effect toxicity are also included. The effects of these aldehydes on biological function, their contribution to human diseases, and the role of nucleic acid and protein carbonylation/oxidation in mutagenicity and cytotoxicity mechanisms, respectively, as well as carbonyl signal transduction and gene expression, are reviewed. Aldehyde metabolic activation and detoxication by metabolizing enzymes are also reviewed, as well as the toxicological and anticancer therapeutic effects of metabolizing enzyme inhibitors. The human health risks from clinical and animal research studies are reviewed, including aldehydes as haptens in allergenic hypersensitivity diseases, respiratory allergies, and idiosyncratic drug toxicity; the potential carcinogenic risks of the carbonyl body burden; and the toxic effects of aldehydes in liver disease, embryo toxicity/teratogenicity, diabetes/hypertension, sclerosing peritonitis, cerebral ischemia/neurodegenerative diseases, and other aging-associated diseases.

  6. Studies on methanol - oxidizing yeast. III. Enzyme.

    Science.gov (United States)

    Volfová, O

    1975-01-01

    Oxidation of methanol, formaldehyde and formic acid was studied in cells and cell-free extract of the yeast Candida boidinii No. 11Bh. Methanol oxidase, an enzyme oxidizing methanol to formaldehyde, was formed inducibly after the addition of methanol to yeast cells. The oxidation of methanol by cell-free extract was dependent on the presence of oxygen and independent of any addition of nicotine-amide nucleotides. Temperature optimum for the oxidation of methanol to formaldehyde was 35 degrees C, pH optimum was 8.5. The Km for methanol was 0.8mM. The cell-free extract exhibited a broad substrate specificity towards primary alcohols (C1--C6). The activity of methanol oxidase was not inhibited by 1mM KCN, EDTA or monoiodoacetic acid. The strongest inhibitory action was exerted by p-chloromercuribenzoate. Both the cells and the cell-free extract contained catalase which participated in the oxidation of methanol to formaldehyde; the enzyme was constitutively formed by the yeast. The pH optimum for the degradation of H2O2 was in the same range as the optimum for methanol oxidation, viz. at 8.5. Catalase was more resistant to high pH than methanol oxidase. The cell-free extract contained also GSH-dependent NAD-formaldehyde dehydrogenase with Km = 0.29mM and NAD-formate dehydrogenase with Km = 55mM. PMID:240764

  7. [Health effect of volatile aldehyde compounds in photocatalytic oxidation of aromatics compounds].

    Science.gov (United States)

    Zhao, Wei-rong; Liao, Qiu-wen; Yang, Ya-nan; Dai, Jiu-song

    2013-05-01

    Photocatalytic oxidation (PCO) of toluene and benzaldehyde in indoor air by N doped TiO2 (N-TiO2) was conducted under UV irradiation of 254 nm. The intermediates were identified and monitored on real-time by proton transfer reaction-mass spectrometry. The health risks of PCO of toluene and benzaldehyde were assessed based on health risk influence index (eta). Results indicated that both the conversion rate and mineralization rate of toluene and benzaldehyde were relatively high, however, the volatile aldehyde compounds (VAs), including acetaldehyde and formaldehyde generated from ring-opening, significantly influenced the health risks of PCO of toluene and benzaldehyde. Acetaldehyde played a crucial role on health risks, which was inclined to desorb from the surface of catalysts, accumulate in gas-phase, and increase the health risks of PCO of the aromatic compounds. The concentration of formaldehyde kept stable at a relatively low level, however its impact cannot be neglected. In the PCO process of toluene and benzaldehyde, eta reached the maximum values of 8 499.68 and 21.43, with the eta(VAs), contribution of VAs to the health risk influence index of outlet, reaching 99.3% and 98.3%, respectively. The average values of eta in the PCO process of 30 min were 932.86 and 8.52, and for which eta(VAs), reached 98.5% and 98.0%, respectively. When PCO of toluene and benzaldehyde reached steady state, eta were 236.09 and 2.30, and eta(VAs) reached 97.9% and 97.8%, respectively. Hence, eta(VAs), can be taken as a characteristic parameter in assessment of health risks of PCO of aromatic compounds.

  8. Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoid-dependent axial patterning in metazoans.

    Science.gov (United States)

    Sobreira, Tiago J P; Marlétaz, Ferdinand; Simões-Costa, Marcos; Schechtman, Deborah; Pereira, Alexandre C; Brunet, Frédéric; Sweeney, Sarah; Pani, Ariel; Aronowicz, Jochanan; Lowe, Christopher J; Davidson, Bradley; Laudet, Vincent; Bronner, Marianne; de Oliveira, Paulo S L; Schubert, Michael; Xavier-Neto, José

    2011-01-01

    Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification. PMID:21169504

  9. Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production

    OpenAIRE

    Sales F.G.; Abreu C.A.M.; Pereira J. A. F. R.

    2004-01-01

    In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose o...

  10. Direct enzyme assay evidence confirms aldehyde reductase function of Ydr541cp and Ygl039wp from Saccharomyces cerevisiae

    Science.gov (United States)

    Aldehyde reductase gene ARI1 is a recently characterized member of intermediate subfamily under SDR (short-chain dehydrogenase/reductase) superfamily that revealed mechanisms of in situ detoxification of furfural and HMF for tolerance of Saccharomyces cerevisiae. Uncharacterized open reading frames ...

  11. Copper-catalyzed oxidative amidation of aldehydes with amine salts: synthesis of primary, secondary, and tertiary amides.

    Science.gov (United States)

    Ghosh, Subhash Chandra; Ngiam, Joyce S Y; Seayad, Abdul M; Tuan, Dang Thanh; Chai, Christina L L; Chen, Anqi

    2012-09-21

    A practical method for the amidation of aldehydes with economic ammonium chloride or amine hydrochloride salts has been developed for the synthesis of a wide variety of amides by using inexpensive copper sulfate or copper(I) oxide as a catalyst and aqueous tert-butyl hydroperoxide as an oxidant. This amidation reaction is operationally straightforward and provides primary, secondary, and tertiary amides in good to excellent yields for most cases utilizing inexpensive and readily available reagents under mild conditions. In situ formation of amine salts from free amines extends the substrate scope of the reaction. Chiral amides are also synthesized from their corresponding chiral amines without detectable racemization. The practicality of this amide formation reaction has been demonstrated in an efficient synthesis of the antiarrhythmic drug N-acetylprocainamide. PMID:22894712

  12. Fatty aldehydes in cyanobacteria are a metabolically flexible precursor for a diversity of biofuel products.

    Directory of Open Access Journals (Sweden)

    Brett K Kaiser

    Full Text Available We describe how pathway engineering can be used to convert a single intermediate derived from lipid biosynthesis, fatty aldehydes, into a variety of biofuel precursors including alkanes, free fatty acids and wax esters. In cyanobacteria, long-chain acyl-ACPs can be reduced to fatty aldehydes, and then decarbonylated to alkanes. We discovered a cyanobacteria class-3 aldehyde-dehydrogenase, AldE, that was necessary and sufficient to instead oxidize fatty aldehyde precursors into fatty acids. Overexpression of enzymes in this pathway resulted in production of 50 to 100 fold more fatty acids than alkanes, and the fatty acids were secreted from the cell. Co-expression of acyl-ACP reductase, an alcohol-dehydrogenase and a wax-ester-synthase resulted in a third fate for fatty aldehydes: conversion to wax esters, which accumulated as intracellular lipid bodies. Conversion of acyl-ACP to fatty acids using endogenous cyanobacterial enzymes may allow biofuel production without transgenesis.

  13. Inhibition of Vibrio harveyi bioluminescence by cerulenin: In vivo evidence for covalent modification of the reductase enzyme involved in aldehyde synthesis

    International Nuclear Information System (INIS)

    Bacterial bioluminescence is very sensitive to cerulenin, a fungal antibiotic which is known to inhibit fatty acid synthesis. When Vibrio harveyi cells pretreated with cerulenin were incubated with [3H]myristic acid in vivo, acylation of the 57-kilodalton reductase subunit of the luminescence-specific fatty acid reductase complex was specifically inhibited. Light emission of wild-type V. harveyi was 20-fold less sensitive to cerulenin at low concentrations (10μg/ml) than that of the dark mutant strain M17, which requires exogenous myristic acid for luminescence because of a defective transferase subunit. The sensitivity of myristic acid-stimulated luminescence in the mutant strain M17 exceeded that of phospholipid synthesis from [14C]acetate, whereas uptake and incorporation of exogenous [14C]myristic acid into phospholipids was increased by cerulenin. The reductase subunit could be labeled by incubating M17 cells with [3H]tetrahydrocerulenin; this labeling was prevented by preincubation with either unlabeled cerulenin or myristic acid. Labeling of the reductase subunit with [3H]tetrahydrocerulenin was also noted in an aldehyde-stimulated mutant (A16) but not in wild-type cells or in another aldehyde-stimulated mutant (M42) in which [3H]myristoyl turnover at the reductase subunit was found to be defective. These results indicate that (i) cerulenin specifically and covalently inhibits the reductase component of aldehyde synthesis, (ii) this enzyme is partially protected from cerulenin inhibition in the wild-type strain in vivo, and (iii) two dark mutants which exhibit similar luminescence phenotypes (mutants A16 and M42) are blocked at different stages of fatty acid reduction

  14. Acrolein, a highly toxic aldehyde generated under oxidative stress in vivo, aggravates the mouse liver damage after acetaminophen overdose.

    Science.gov (United States)

    Arai, Tomoya; Koyama, Ryo; Yuasa, Makoto; Kitamura, Daisuke; Mizuta, Ryushin

    2014-01-01

    Although acetaminophen-induced liver injury in mice has been extensively studied as a model of human acute drug-induced hepatitis, the mechanism of liver injury remains unclear. Liver injury is believed to be initiated by metabolic conversion of acetaminophen to the highly reactive intermediate N-acetyl p-benzoquinoneimine, and is aggravated by subsequent oxidative stress via reactive oxygen species (ROS), including hydrogen peroxide (H2O2) and the hydroxyl radical (•OH). In this study, we found that a highly toxic unsaturated aldehyde acrolein, a byproduct of oxidative stress, has a major role in acetaminophen-induced liver injury. Acetaminophen administration in mice resulted in liver damage and increased acrolein-protein adduct formation. However, both of them were decreased by treatment with N-acetyl-L-cysteine (NAC) or sodium 2-mercaptoethanesulfonate (MESNA), two known acrolein scavengers. The specificity of NAC and MESNA was confirmed in cell culture, because acrolein toxicity, but not H2O2 or •OH toxicity, was inhibited by NAC and MESNA. These results suggest that acrolein may be more strongly correlated with acetaminophen-induced liver injury than ROS, and that acrolein produced by acetaminophen-induced oxidative stress can spread from dying cells at the primary injury site, causing damage to the adjacent cells and aggravating liver injury.

  15. CuO and Ag2O/CuO Catalyzed Oxidation of Aldehydes to the Corresponding Carboxylic Acids by Molecular Oxygen

    Directory of Open Access Journals (Sweden)

    Yaowu Sha

    2008-04-01

    Full Text Available Furfural was oxidized to furoic acid by molecular oxygen under catalysis by 150nm-sized Ag2O/CuO (92% or simply CuO (86.6%. When 30 nm-size catalyst was used,the main product was a furfural Diels-Alder adduct. Detailed reaction conditions andregeneration of catalysts were investigated. Under optimal conditions, a series of aromaticand aliphatic aldehydes were oxidized to the corresponding acids in good yields.

  16. A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

    OpenAIRE

    Andrew Bogdan; D. Tyler McQuade

    2009-01-01

    We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leavi...

  17. Immobilisation and characterisation of biocatalytic co-factor recycling enzymes, glucose dehydrogenase and NADH oxidase, on aldehyde functional ReSyn™ polymer microspheres.

    Science.gov (United States)

    Twala, Busisiwe V; Sewell, B Trevor; Jordaan, Justin

    2012-05-10

    The use of enzymes in industrial applications is limited by their instability, cost and difficulty in their recovery and re-use. Immobilisation is a technique which has been shown to alleviate these limitations in biocatalysis. Here we describe the immobilisation of two biocatalytically relevant co-factor recycling enzymes, glucose dehydrogenase (GDH) and NADH oxidase (NOD) on aldehyde functional ReSyn™ polymer microspheres with varying functional group densities. The successful immobilisation of the enzymes on this new high capacity microsphere technology resulted in the maintenance of activity of ∼40% for GDH and a maximum of 15.4% for NOD. The microsphere variant with highest functional group density of ∼3500 μmol g⁻¹ displayed the highest specific activity for the immobilisation of both enzymes at 33.22 U mg⁻¹ and 6.75 U mg⁻¹ for GDH and NOD with respective loading capacities of 51% (0.51 mg mg⁻¹) and 129% (1.29 mg mg⁻¹). The immobilised GDH further displayed improved activity in the acidic pH range. Both enzymes displayed improved pH and thermal stability with the most pronounced thermal stability for GDH displayed on ReSyn™ A during temperature incubation at 65 °C with a 13.59 fold increase, and NOD with a 2.25-fold improvement at 45 °C on the same microsphere variant. An important finding is the suitability of the microspheres for stabilisation of the multimeric protein GDH.

  18. A biphasic oxidation of alcohols to aldehydes and ketones using a simplified packed-bed microreactor

    Directory of Open Access Journals (Sweden)

    Andrew Bogdan

    2009-04-01

    Full Text Available We demonstrate the preparation and characterization of a simplified packed-bed microreactor using an immobilized TEMPO catalyst shown to oxidize primary and secondary alcohols via the biphasic Anelli-Montanari protocol. Oxidations occurred in high yields with great stability over time. We observed that plugs of aqueous oxidant and organic alcohol entered the reactor as plugs but merged into an emulsion on the packed-bed. The emulsion coalesced into larger plugs upon exiting the reactor, leaving the organic product separate from the aqueous by-products. Furthermore, the microreactor oxidized a wide range of alcohols and remained active in excess of 100 trials without showing any loss of catalytic activity.

  19. CuCl-Catalyzed Aerobic Oxidation of Allylic and Propargylic Alcohols to Aldehydes or Ketones with 1 : 1 Combination of Phenanthroline and Bipyridine as the Ligandst%CuCl-Catalyzed Aerobic Oxidation of Allylic and Propargylic Alcohols to Aldehydes or Ketones with 1 : 1 Combination of Phenanthroline and Bipyridine as the Ligandst

    Institute of Scientific and Technical Information of China (English)

    刘宇; 麻生明

    2012-01-01

    We developed a modified protocol for the oxidation of 2,3-allenyl alcohols using CuCI with l : 1 combination of phenanthroline and bipyridine as the catalyst. To further investigate the applicability of this system, other types of alcohols such as allylic and propargylic alcohols have been tested: we found that both allylic and propargylic alcohols may be oxidized to the corresponding aldehydes or ketones using molecular oxygen in air as the oxidant with moderate to excellent yields.

  20. The Effect of Polyunsaturated Aldehydes on Skeletonema marinoi (Bacillariophyceae: The Involvement of Reactive Oxygen Species and Nitric Oxide

    Directory of Open Access Journals (Sweden)

    Alessandra A. Gallina

    2014-07-01

    Full Text Available Nitric oxide (NO and reactive oxygen species (ROS production was investigated in the marine diatom, Skeletonema marinoi (SM, exposed to 2E,4E/Z-decadienal (DECA, 2E,4E/Z-octadienal (OCTA, 2E,4E/Z-heptadienal (HEPTA and a mix of these last two (MIX. When exposed to polyunsaturated aldehydes (PUA, a decrease of NO was observed, proportional to the PUA concentration (85% of the initial level after 180 min with 66 µM DECA. Only OCTA, HEPTA and MIX induced a parallel increase of ROS, the highest (2.9-times the control with OCTA concentrations twice the EC50 for growth at 24 h (20 μM. The synthesis of carotenoids belonging to the xanthophyll cycle (XC was enhanced during exposure, suggesting their antioxidant activity. Our data provide evidence that specific pathways exist as a reaction to PUA and that they depend upon the PUA used and/or the diatom species. In fact, Phaeodactylum tricornutum (PT produces NO in response to DECA, but not to OCTA. We advance the hypothesis that SM perceives OCTA and HEPTA as intra-population infochemicals (as it produces PUA, while PT (non-PUA producing species perceives them as allelochemicals. The ability to produce and to use PUA as infochemicals may underlie ecological traits of different diatom species and modulate ecological success in natural communities.

  1. The dynamics of oxidative enzymes during the white winemaking

    OpenAIRE

    Popescu, Carmen; Elena POSTOLACHE; Gabriela RAPEANU; Mircea BULANCEA; Traian HOPULELE

    2010-01-01

    The aim of this paper was to monitorise the evolution of the oxidative enzymes activity during the process of winemaking from white grapes. The second objective was to evaluate the browning capacity of the grape must during the alcoholic fermentation stage and in the resulting wine. During the alcoholic fermentation,the activity of the oxidative enzymes was reduced, thus the enzymatic activity of the peroxydase decreased by approximately 60% of the initial activity, the enzymatic activity of ...

  2. Early bichemical markers of effects: Enzyme induction, oncogene activation and markers of oxidative damage

    DEFF Research Database (Denmark)

    Poulsen, Henrik E.; Loft, Steffen

    1995-01-01

    Early bichemical marker, enzyme induction, oncogene activation, oxidative damage, low-density lipoprotein......Early bichemical marker, enzyme induction, oncogene activation, oxidative damage, low-density lipoprotein...

  3. Formation of gold clusters on La-Ni mixed oxides and its catalytic performance for isomerization of allylic alcohols to saturated aldehydes

    International Nuclear Information System (INIS)

    Au/NiO catalyzed the isomerization of allylic alcohols to afford saturated aldehydes. La-Ni mixed oxide could stabilize Au(III) and afford gold clusters smaller than 1 nm by H2 reduction. The resulting Au clusters on La-Ni-O exhibited superior catalytic performance to Au/NiO for the isomerization of internal allylic alcohol, 2-octen-1-ol to octanal. (author)

  4. Aldehyde dehydrogenase 2 protects human umbilical vein endothelial cells against oxidative damage and increases endothelial nitric oxide production to reverse nitroglycerin tolerance.

    Science.gov (United States)

    Hu, X Y; Fang, Q; Ma, D; Jiang, L; Yang, Y; Sun, J; Yang, C; Wang, J S

    2016-06-10

    Medical nitroglycerin (glyceryl trinitrate, GTN) use is limited principally by tolerance typified by a decrease in nitric oxide (NO) produced by biotransformation. Such tolerance may lead to endothelial dysfunction by inducing oxidative stress. In vivo studies have demonstrated that aldehyde dehydrogenase 2 (ALDH2) plays important roles in GTN biotransformation and tolerance. Thus, modification of ALDH2 expression represents a potentially effective strategy to prevent and reverse GTN tolerance and endothelial dysfunction. In this study, a eukaryotic expression vector containing the ALDH2 gene was introduced into human umbilical vein endothelial cells (HUVECs) by liposome-mediated transfection. An indirect immunofluorescence assay showed that ALDH2 expression increased 24 h after transfection. Moreover, real-time polymerase chain reaction and western blotting revealed significantly higher ALDH2 mRNA and protein expression in the gene-transfected group than in the two control groups. GTN tolerance was induced by treating HUVECs with 10 mM GTN for 16 h + 10 min, which significantly decreased NO levels in control cells, but not in those transfected with ALDH2. Overexpression of ALDH2 increased cell survival against GTN-induced cytotoxicity and conferred protection from oxidative damage resulting from nitrate tolerance, accompanied by decreased production of intracellular reactive oxygen species and reduced expression of heme oxygenase 1. Furthermore, ALDH2 overexpression promoted Akt phosphorylation under GTN tolerance conditions. ALDH2 gene transfection can reverse and prevent tolerance to GTN through its bioactivation and protect against oxidative damage, preventing the development of endothelial dysfunction.

  5. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented.

  6. Isolated tumoral pyruvate dehydrogenase can synthesize acetoin which inhibits pyruvate oxidation as well as other aldehydes.

    Science.gov (United States)

    Baggetto, L G; Lehninger, A L

    1987-05-29

    Oxidation of 1 mM pyruvate by Ehrlich and AS30-D tumor mitochondria is inhibited by acetoin, an unusual and important metabolite of pyruvate utilization by cancer cells, by acetaldehyde, methylglyoxal and excess pyruvate. The respiratory inhibition is reversed by other substrates added to pyruvate and also by 0.5 mM ATP. Kinetic properties of pyruvate dehydrogenase complex isolated from these tumor mitochondria have been studied. This complex appears to be able to synthesize acetoin from acetaldehyde plus pyruvate and is competitively inhibited by acetoin. The role of a new regulatory pattern for tumoral pyruvate dehydrogenase is presented. PMID:3593337

  7. Wet Aerobic Oxidation of Lignin into Aromatic Aldehydes Catalysed by a Perovskite-type Oxide: LaFe1-xCuxO3 (x=0, 0.1, 0.2

    Directory of Open Access Journals (Sweden)

    Lu Lin

    2009-07-01

    Full Text Available The perovskite-type oxide catalyst LaFe1-xCuxO3 (x=0, 0.1, 0.2 was prepared by the sol–gel method, and tested as a catalyst in the wet aerobic oxidation (WAO of lignin into aromatic aldehydes. The lignin conversion and the yield of each aromatic aldehyde were significantly enhanced in the catalytic process, compared with the non-catalyzed process. Moreover, it was shown that the stability of activity and structure of LaFe1-xCuxO3 (x=0, 0.1, 0.2 remained nearly unchanged after a series of successive recyclings of the catalytic reactions, indicating it was an efficient and recyclable heterogeneous catalyst for the conversion of lignin into aromatic aldehydes in the WAO process.

  8. Glycosylation of resveratrol protects it from enzymic oxidation.

    Science.gov (United States)

    Regev-Shoshani, Gilly; Shoseyov, Oded; Bilkis, Itzhak; Kerem, Zohar

    2003-01-01

    Plant polyphenols, including dietary polyphenols such as resveratrol, are important components in the plant antioxidant and defence systems. They are also known to exert beneficial effects on human health through diet. As they are produced, these polyphenols may be subjected to deleterious enzymic oxidation by the plant polyphenol oxidases. They are generally synthesized as glycosides like 5,4'-dihydroxystilbene-3-O-beta-D-glucopyranoside, the 3-glucoside of resveratrol. The effects of the glycosylation and methylation of the parent resveratrol on its enzymic oxidation were studied. Methyl and glucosyl derivatives were synthesized using simple one-step methodologies. The kinetics of their enzymic oxidation by tyrosinases were defined. Substitution at the p-hydroxy group, by either glucose or methyl, abolished enzymic oxidation by both mushroom and grape tyrosinases. Substitution at the m-hydroxy group with methyl had a small effect, but substitution with glucose resulted in a much lower affinity of the enzymes for the glycoside. We suggest that glycosylation of polyphenols in nature helps to protect these vital molecules from enzymic oxidation, extending their half-life in the cell and maintaining their beneficial antioxidant capacity and biological properties. PMID:12697026

  9. Fatty Aldehyde and Fatty Alcohol Metabolism: Review and Importance for Epidermal Structure and Function

    Science.gov (United States)

    Rizzo, William B.

    2014-01-01

    Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids including fatty alcohols, sphingolipids, ether glycerolipids, isoprenoid alcohols and certain aliphatic lipids that undergo α- or ω-oxidation. The fatty aldehyde generated by these pathways is chiefly metabolized to fatty acid by fatty aldehyde dehydrogenase (FALDH, alternately known as ALDH3A2), which also functions to oxidize fatty alcohols as a component of the fatty alcohol:NAD oxidoreductase (FAO) enzyme complex. Genetic deficiency of FALDH/FAO in patients with Sjögren-Larsson syndrome (SLS) results in accumulation of fatty aldehydes, fatty alcohols and related lipids (ether glycerolipids, wax esters) in cultured keratinocytes. These biochemical changes are associated with abnormalities in formation of lamellar bodies in the stratum granulosum and impaired delivery of their precursor membranes to the stratum corneum (SC). The defective extracellular SC membranes are responsible for a leaky epidermal water barrier and ichthyosis. Although lamellar bodies appear to be the pathogenic target for abnormal fatty aldehyde/alcohol metabolism in SLS, the precise biochemical mechanisms are yet to be elucidated. Nevertheless, studies in SLS highlight the critical importance of FALDH and normal fatty aldehyde/alcohol metabolism for epidermal function. PMID:24036493

  10. Novel oxidation of aromatic aldehydes catalyzed by Preyssler's anion, [NaP{sub 5}W{sub 30}O{sub 110}]{sup 14-}

    Energy Technology Data Exchange (ETDEWEB)

    Bamoharram, F.F.; Roshani, M.; Moghayadi, M. [Islamic Azad University-Mashhad Branch, Mashhad (Iran, Islamic Republic of). Dept. of Chemistry]. E-mail: abamoharram@yahoo.com; Alizadeh, M.H. [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of). Dept. of Chemistry; Razavi, H. [Georgetown University, Washington, DC (United States). Dept. of Chemistry

    2006-05-15

    Preyssler's anion, with formula [NaP{sub 5}W{sub 30}O{sub 110}]{sup 14-}, catalyzes the oxidation of aromatic aldehydes to related carboxylic acids by hydrogen peroxide as oxidizing agent, under microwave irradiation, or at 70 deg C. Both homogeneous and heterogeneous Preyssler's catalysts (as H{sub 14}[NaP{sub 5}W{sub 30}O{sub 110}]) were used and had their activity compared with those of some Keggin structures. Our data indicate that Sodium30-tungsto pentaphosphate, the so-called Preyssler's anion, with high hydrolytic (pH=0-12) and thermal stability is the best catalyst with high yield and good selectivity. Under microwave irradiation, this polyanion supported on SiO{sub 2} was found to be an excellent catalyst for aldehydes with low loss factor in 1-2 min (the loss factor is a measure of the ability of the material to dissipate energy). The effects of various parameters, including catalyst type, nature of the substituent in the aldehyde and temperature, on the yield of the carboxylic acids were studied. (author)

  11. Microsphere coated substrate containing reactive aldehyde groups

    Science.gov (United States)

    Rembaum, Alan (Inventor); Yen, Richard C. K. (Inventor)

    1984-01-01

    A synthetic organic resin is coated with a continuous layer of contiguous, tangential, individual microspheres having a uniform diameter preferably between 100 Angstroms and 2000 Angstroms. The microspheres are an addition polymerized polymer of an unsaturated aldehyde containing 4 to 20 carbon atoms and are covalently bonded to the substrate by means of high energy radiation grafting. The microspheres contain reactive aldehyde groups and can form conjugates with proteins such as enzymes or other aldehyde reactive materials.

  12. Sjögren-Larsson syndrome. Deficient activity of the fatty aldehyde dehydrogenase component of fatty alcohol:NAD+ oxidoreductase in cultured fibroblasts.

    OpenAIRE

    Rizzo, W B; Craft, D A

    1991-01-01

    Sjögren-Larsson syndrome (SLS) is an inherited disorder associated with impaired fatty alcohol oxidation due to deficient activity of fatty alcohol:NAD+ oxidoreductase (FAO). FAO is a complex enzyme which consists of two separate proteins that sequentially catalyze the oxidation of fatty alcohol to fatty aldehyde and fatty acid. To determine which enzymatic component of FAO was deficient in SLS, we assayed fatty aldehyde dehydrogenase (FALDH) and fatty alcohol dehydrogenase in cultured fibrob...

  13. Reversible, partial inactivation of plant betaine aldehyde dehydrogenase by betaine aldehyde: mechanism and possible physiological implications.

    Science.gov (United States)

    Zárate-Romero, Andrés; Murillo-Melo, Darío S; Mújica-Jiménez, Carlos; Montiel, Carmina; Muñoz-Clares, Rosario A

    2016-04-01

    In plants, the last step in the biosynthesis of the osmoprotectant glycine betaine (GB) is the NAD(+)-dependent oxidation of betaine aldehyde (BAL) catalysed by some aldehyde dehydrogenase (ALDH) 10 enzymes that exhibit betaine aldehyde dehydrogenase (BADH) activity. Given the irreversibility of the reaction, the short-term regulation of these enzymes is of great physiological relevance to avoid adverse decreases in the NAD(+):NADH ratio. In the present study, we report that the Spinacia oleracea BADH (SoBADH) is reversibly and partially inactivated by BAL in the absence of NAD(+)in a time- and concentration-dependent mode. Crystallographic evidence indicates that the non-essential Cys(450)(SoBADH numbering) forms a thiohemiacetal with BAL, totally blocking the productive binding of the aldehyde. It is of interest that, in contrast to Cys(450), the catalytic cysteine (Cys(291)) did not react with BAL in the absence of NAD(+) The trimethylammonium group of BAL binds in the same position in the inactivating or productive modes. Accordingly, BAL does not inactivate the C(450)SSoBADH mutant and the degree of inactivation of the A(441)I and A(441)C mutants corresponds to their very different abilities to bind the trimethylammonium group. Cys(450)and the neighbouring residues that participate in stabilizing the thiohemiacetal are strictly conserved in plant ALDH10 enzymes with proven or predicted BADH activity, suggesting that inactivation by BAL is their common feature. Under osmotic stress conditions, this novel partial and reversible covalent regulatory mechanism may contribute to preventing NAD(+)exhaustion, while still permitting the synthesis of high amounts of GB and avoiding the accumulation of the toxic BAL.

  14. Isolation of liver aldehyde oxidase containing fractions from different animals and determination of kinetic parameters for benzaldehyde

    Directory of Open Access Journals (Sweden)

    Kadam R

    2008-01-01

    Full Text Available Aldehyde oxidase activity containing fractions from rabbit, guinea pig, rat and mouse livers were obtained by heat treatment and ammonium sulfate precipitation. Aldehyde oxidase activity was observed in rabbit and guinea pig livers, while aldehyde oxidase activity was absent in rat and mouse liver fractions. Enzyme kinetic parameters, K m and V max , were determined for the oxidation of benzaldehyde to benzoic acid by rabbit and guinea pig liver fractions, by spectrophotometric method, with potassium ferricyanide as the electron acceptor. The K m values obtained for both animal liver fractions were in the range of 10.3-19.1 µM.

  15. Surviving environmental stress: the role of betaine aldehyde dehydrogenase in marine crustaceans

    Directory of Open Access Journals (Sweden)

    NA Stephens-Camacho

    2015-02-01

    Full Text Available Betaine aldehyde dehydrogenase (BADH belongs to the aldehyde dehydrogenases (ALDH family, an ancestral group of enzymes responsible for aldehyde detoxification in several organisms. The BADH enzyme catalyzes the irreversible oxidation of betaine aldehyde to glycine betaine (GB an important osmoptrotector and osmoregulator accumulated in response to cellular osmotic stress. The BADH enzymes have been extensively described in terrestrial organisms, but information in marine crustaceans remains scarce. Research on crustacean stress-adaptive capacity to environmental stressors relates GB accumulation in response to salinity variations. Although GB de novo synthesis is confirmed on crustaceans, its metabolic pathways and regulation mechanism are unexplored. In this work, the state of the knowledge of betaine aldehyde dehydrogenase enzymes in marine crustaceans is summarized, as a mechanism to overcome the deleterious effects of changes in temperature, salinity and dissolved oxygen concentration in seawater. The purpose of this review is to provide a more comprehensive overview to set the basis for exploring novel functions and properties of BADHs on the response of crustaceans to environmental stress.

  16. Solvent-free oxidation of aldehydes to acids by TBHP using environmental-friendly MnO$^{−1}_{4}$-exchanged Mg-Al hydrotalcite catalyst

    Indian Academy of Sciences (India)

    Vasant R Choudhary; Deepa K Dumbre; Vijay S Narkhede

    2012-07-01

    A number of hydrotalcite (Mg-Al, Mn-Al, Co-Al, Ni-Al, Mg-Fe, Mg-Cr and Cu-Al) catalysts, with or without MnO$^{−1}_{4}$-exchange, were evaluated for their performance in the solvent-free oxidation of benzaldehyde to benzoic acid by tert-butyl hydroperoxide under reflux in the absence of any solvent. The MnO$^{−1}_{4}$-exchanged Mg-Al-hydrotalcite (Mg/Al = 10) showed high activity in the oxidation of different aromatic and aliphatic aldehydes to their corresponding acids and also showed excellent reusability in the oxidation process which is environmental-friendly.

  17. Alcohol and Aldehyde Dehydrogenases: Retinoid Metabolic Effects in Mouse Knockout Models

    OpenAIRE

    Kumar, Sandeep; Sandell, Lisa L.; Trainor, Paul A; Koentgen, Frank; Duester, Gregg

    2011-01-01

    Retinoic acid (RA) is the active metabolite of vitamin A (retinol) that controls growth and development. The first step of RA synthesis is controlled by enzymes of the alcohol dehydrogenase (ADH) and retinol dehydrogenase (RDH) families that catalyze oxidation of retinol to retinaldehyde. The second step of RA synthesis is controlled by members of the aldehyde dehydrogenase (ALDH) family also known as retinaldehyde dehydrogenase (RALDH) that further oxidize retinaldehyde to produce RA. RA fun...

  18. The use of tomato aminoaldehyde dehydrogenase 1 for the detection of aldehydes in fruit distillates.

    Science.gov (United States)

    Frömmel, Jan; Tarkowski, Petr; Kopečný, David; Šebela, Marek

    2016-09-25

    Plant NAD(+)-dependent aminoaldehyde dehydrogenases (AMADHs, EC 1.2.1.19) belong to the family 10 of aldehyde dehydrogenases. They participate in the metabolism of polyamines or osmoprotectants. The enzymes are characterized by their broad substrate specificity covering ω-aminoaldehydes, aliphatic and aromatic aldehydes as well as nitrogen-containing heterocyclic aldehydes. The isoenzyme 1 from tomato (Solanum lycopersicum; SlAMADH1) oxidizes aliphatic aldehydes very efficiently and converts also furfural, its derivatives or benzaldehyde, which are present at low concentrations in alcoholic distillates such as fruit brandy. In this work, SlAMADH1 was examined as a bioanalytical tool for their detection. These aldehydes arise from fermentation processes or thermal degradation of sugars and their presence is related to health complications after consumption including nausea, emesis, sweating, decrease in blood pressure, hangover headache, among others. Sixteen samples of slivovitz (plum brandy) from local producers in Moravia, Czech Republic, were analyzed for their aldehyde content using a spectrophotometric activity assay with SlAMADH1. In all cases, there were oxidative responses observed when monitoring NADH production in the enzymatic reaction. Aldehydes in the distillate samples were also subjected to a standard determination using reversed-phase HPLC with spectrophotometric and tandem mass spectrometric detection after a derivatization with 2,4-dinitrophenylhydrazine. Results obtained by both methods were found to correlate well for a majority of the analyzed samples. The possible applicability of SlAMADH1 for the evaluation of aldehyde content in food and beverages has now been demonstrated. PMID:26703808

  19. Self-assembled monolayers of 1-alkenes on oxidized platinum surfaces as platforms for immobilized enzymes for biosensing

    Science.gov (United States)

    Alonso, Jose Maria; Bielen, Abraham A. M.; Olthuis, Wouter; Kengen, Servé W. M.; Zuilhof, Han; Franssen, Maurice C. R.

    2016-10-01

    Alkene-based self-assembled monolayers grafted on oxidized Pt surfaces were used as a scaffold to covalently immobilize oxidase enzymes, with the aim to develop an amperometric biosensor platform. NH2-terminated organic layers were functionalized with either aldehyde (CHO) or N-hydroxysuccinimide (NHS) ester-derived groups, to provide anchoring points for enzyme immobilization. The functionalized Pt surfaces were characterized by X-ray photoelectron spectroscopy (XPS), static water contact angle (CA), infrared reflection absorption spectroscopy (IRRAS) and atomic force microscopy (AFM). Glucose oxidase (GOX) was covalently attached to the functionalized Pt electrodes, either with or without additional glutaraldehyde crosslinking. The responses of the acquired sensors to glucose concentrations ranging from 0.5 to 100 mM were monitored by chronoamperometry. Furthermore, lactate oxidase (LOX) and human hydroxyacid oxidase (HAOX) were successfully immobilized onto the PtOx surface platform. The performance of the resulting lactate sensors was investigated for lactate concentrations ranging from 0.05 to 20 mM. The successful attachment of active enzymes (GOX, LOX and HAOX) on Pt electrodes demonstrates that covalently functionalized PtOx surfaces provide a universal platform for the development of oxidase enzyme-based sensors.

  20. Reducing the Oxidation Level of Dextran Aldehyde in a Chitosan/Dextran-Based Surgical Hydrogel Increases Biocompatibility and Decreases Antimicrobial Efficacy.

    Science.gov (United States)

    Chan, Maggie; Brooks, Heather J L; Moratti, Stephen C; Hanton, Lyall R; Cabral, Jaydee D

    2015-06-16

    A highly oxidized form of a chitosan/dextran-based hydrogel (CD-100) containing 80% oxidized dextran aldehyde (DA-100) was developed as a post-operative aid, and found to significantly prevent adhesion formation in endoscopic sinus surgery (ESS). However, the CD-100 hydrogel showed moderate in vitro cytotoxicity to mammalian cell lines, with the DA-100 found to be the cytotoxic component. In order to extend the use of the hydrogel to abdominal surgeries, reformulation using a lower oxidized DA (DA-25) was pursued. The aim of the present study was to compare the antimicrobial efficacy, in vitro biocompatibility and wound healing capacity of the highly oxidized CD-100 hydrogel with the CD-25 hydrogel. Antimicrobial studies were performed against a range of clinically relevant abdominal microorganisms using the micro-broth dilution method. Biocompatibility testing using human dermal fibroblasts was assessed via a tetrazolium reduction assay (MTT) and a wound healing model. In contrast to the original DA-100 formulation, DA-25 was found to be non-cytotoxic, and showed no overall impairment of cell migration, with wound closure occurring at 72 h. However, the lower oxidation level negatively affected the antimicrobial efficacy of the hydrogel (CD-25). Although the CD-25 hydrogel's antimicrobial efficacy and anti-fibroblast activity is decreased when compared to the original CD-100 hydrogel formulation, previous in vivo studies show that the CD-25 hydrogel remains an effective, biocompatible barrier agent in the prevention of postoperative adhesions.

  1. Reducing the Oxidation Level of Dextran Aldehyde in a Chitosan/Dextran-Based Surgical Hydrogel Increases Biocompatibility and Decreases Antimicrobial Efficacy

    Directory of Open Access Journals (Sweden)

    Maggie Chan

    2015-06-01

    Full Text Available A highly oxidized form of a chitosan/dextran-based hydrogel (CD-100 containing 80% oxidized dextran aldehyde (DA-100 was developed as a post-operative aid, and found to significantly prevent adhesion formation in endoscopic sinus surgery (ESS. However, the CD-100 hydrogel showed moderate in vitro cytotoxicity to mammalian cell lines, with the DA-100 found to be the cytotoxic component. In order to extend the use of the hydrogel to abdominal surgeries, reformulation using a lower oxidized DA (DA-25 was pursued. The aim of the present study was to compare the antimicrobial efficacy, in vitro biocompatibility and wound healing capacity of the highly oxidized CD-100 hydrogel with the CD-25 hydrogel. Antimicrobial studies were performed against a range of clinically relevant abdominal microorganisms using the micro-broth dilution method. Biocompatibility testing using human dermal fibroblasts was assessed via a tetrazolium reduction assay (MTT and a wound healing model. In contrast to the original DA-100 formulation, DA-25 was found to be non-cytotoxic, and showed no overall impairment of cell migration, with wound closure occurring at 72 h. However, the lower oxidation level negatively affected the antimicrobial efficacy of the hydrogel (CD-25. Although the CD-25 hydrogel’s antimicrobial efficacy and anti-fibroblast activity is decreased when compared to the original CD-100 hydrogel formulation, previous in vivo studies show that the CD-25 hydrogel remains an effective, biocompatible barrier agent in the prevention of postoperative adhesions.

  2. Remarkable effect of bimetallic nanocluster catalysts for aerobic oxidation of alcohols: combining metals changes the activities and the reaction pathways to aldehydes/carboxylic acids or esters.

    Science.gov (United States)

    Kaizuka, Kosuke; Miyamura, Hiroyuki; Kobayashi, Shū

    2010-11-01

    Selective oxidation of alcohols catalyzed by novel carbon-stabilized polymer-incarcerated bimetallic nanocluster catalysts using molecular oxygen has been developed. The reactivity and the selectivity were strongly dependent on the combination of metals and solvent systems; aldehydes and ketones were obtained by the gold/platinum catalyst in benzotrifluoride, and esters were formed by the gold/palladium catalyst in methanol. To the best of our knowledge, this is the first example that the reaction pathway has been changed dramatically in gold catalysis by combining with a second metal. The differences in the activity and the selectivity are considered to be derived from the difference in the structure of the bimetallic clusters.

  3. Application of ultraviolet, ozone, and advanced oxidation treatments to washwaters to destroy nitrosamines, nitramines, amines, and aldehydes formed during amine-based carbon capture.

    Science.gov (United States)

    Shah, Amisha D; Dai, Ning; Mitch, William A

    2013-03-19

    Although amine-based CO(2) absorption is a leading contender for full-scale postcombustion CO(2) capture at power plants, concerns have been raised about the potential release of carcinogenic N-nitrosamines and N-nitramines formed by reaction of exhaust gas NO(x) with the amines. Experiments with a laboratory-scale pilot unit suggested that washwater units meant to scrub contaminants from absorber unit exhaust could potentially serve as a source of N-nitrosamines via reactions of residual NO(x) with amines accumulating in the washwater. Dosage requirements for the continuous treatment of the washwater recycle line with ultraviolet (UV) light for destruction of N-nitrosamines and N-nitramines, and with ozone or hydroxyl radical-based advanced oxidation processes (AOPs) for destruction of amines and aldehydes, were evaluated. Although capture synergies between UV and ozone treatments.

  4. Multi-enzyme catalyzed rapid ethanol lowering in vitro.

    Science.gov (United States)

    Whitmire, D R; Chambers, R P; Dillon, A R

    1991-10-01

    Ethanol was oxidized to acetate by an enzyme system using yeast alcohol dehydrogenase (YADH), yeast aldehyde dehydrogenase (YALDH), and lactic dehydrogenase (LDH) recycling NAD in two model duodenal fluids and in canine duodenal aspirate in vitro. Sufficient enzyme activities were maintained to convert as much as 34% of the original ethanol to acetate with negligible acetaldehyde accumulation.

  5. Quantification of the 2-Deoxyribonolactone and Nucleoside 5 '-Aldehyde Products of 2-Deoxyribose Oxidation in DNA and Cells by Isotope-Dilution Gas Chromatography Mass Spectrometry: Differential Effects of gamma-Radiation and Fe[superscript 2+]-EDTA

    OpenAIRE

    Chan, Wan Simon; Chen, Bingzi; Wang, Lianrong; Taghizadeh, Koli; DeMott, Michael S.; Peter C. Dedon

    2010-01-01

    The oxidation of 2-deoxyribose in DNA has emerged as a critical determinant of the cellular toxicity of oxidative damage to DNA, with oxidation of each carbon producing a unique spectrum of electrophilic products. We have developed and validated an isotope-dilution gas chromatography-coupled mass spectrometry (GC−MS) method for the rigorous quantification of two major 2-deoxyribose oxidation products: the 2-deoxyribonolactone abasic site of 1′-oxidation and the nucleoside 5′-aldehyde of 5′-ox...

  6. Quantification of the 2-deoxyribonolactone and nucleoside 5’-aldehyde products of 2-deoxyribose oxidation in DNA and cells by isotope-dilution gas chromatography mass spectrometry: Differential effects of γ-radiation and Fe2+-EDTA

    OpenAIRE

    Chan, Wan; Chen, Bingzi; Wang, Lianrong; Taghizadeh, Koli; DeMott, Michael S.; Peter C. Dedon

    2010-01-01

    The oxidation of 2-deoxyribose in DNA has emerged as a critical determinant of the cellular toxicity of oxidative damage to DNA, with oxidation of each carbon producing a unique spectrum of electrophilic products. We have developed and validated an isotope-dilution gas chromatography-coupled mass spectrometry (GC-MS) method for the rigorous quantification of two major 2-deoxyribose oxidation products: the 2-deoxyribonolactone abasic site of 1’-oxidation and the nucleoside 5’-aldehyde of 5’-ox...

  7. Kinetic and mechanistic studies on the atmospheric oxidation of oxygenated Volatile Organic Compounds: aldehyde, ketones and esters (solvents or car emissions); Etudes des cinetiques et mecanismes de degradation atmospherique de composes organiques volatils oxygenes: aldehydes, cetones et esters (emissions automobiles et solvants)

    Energy Technology Data Exchange (ETDEWEB)

    Thevenet, R.

    2000-12-01

    The atmospheric fate of oxygenated Volatile Organic Compounds (VOCs), used as solvents or emitted by fuel car combustion, is reported in this thesis. Four saturated aldehydes (propanal, isobutyr-aldehyde, pivalaldehyde and valeraldehyde), two unsaturated aldehydes (acrolein and croton-aldehyde), three ketones (2-butanone, 2-methyl-4-pentanone, 2,4-dimethyl-3-pentanone) and three esters (methyl acrylate, methyl methacrylate and methyl pyruvate) have been studied. The rate coefficients of the OH reactions with the VOCs have been measured over the temperature range 233-372 K, using the Pulsed Laser Photolysis - Laser Induced Fluorescence (PLP-LIF) technique. The photo-reactor have been used to measure the reaction rate constants of these VOCs with Cl or O{sub 3} by the relative method. The obtained results are the first determinations for the most of the VOCs. In a second part, the atmospheric oxidation of the VOCs, initiated by OH, have been studied in smog chambers. Analysis have been performed by IRTF and GC-MS. Photo-reactors have been used, a laboratory photo-reactor in Orleans (160 L) and the European Photo-reactor EUPHORE (200 m{sup 3} with sunlight irradiation). The main oxidation pathways of the VOCs and the main products have been identified. For most of the VOCs, there are the first studies. These experimental results leaded to discuss the atmospheric fate of the VOCs in terms of lifetimes and oxidation products of the VOCs. The tropospheric ozone forming potential of the VOCs and their role in the photo-oxidant pollution have been evaluated. (author)

  8. Hepatic fatty acid oxidation : activity, localization and function of some enzymes involved

    NARCIS (Netherlands)

    A. van Tol (Arie)

    1971-01-01

    textabstractFatty acid oxidation is an important pathway for energy production in mammals and birds. In animal tissues the enzymes of fatty acid oxidation are located in the mitochondrion. Recent reports suggest that this is not the case in Castor bean endosperm. In this tissue the enzymes of B-oxid

  9. Inhibitory effects of Ruta graveolens L. extract on guinea pig liver aldehyde oxidase.

    Science.gov (United States)

    Pirouzpanah, Saieed; Saieed, Pirouzpanah; Rashidi, Mohammad Reza; Reza, Rashidi Mohammad; Delazar, Abbas; Abbas, Delazar; Razavieh, Seyyed-Vali; Seyyedvali, Razavieh; Hamidi, Aliasghar; Aliasghar, Hamidi

    2006-01-01

    Ruta graveolens L. is a flavonoid-containing medicinal plant with various biological properties. In the present study, the effects of R. graveolens extract on aldehyde oxidase, a molybdenum hydroxylase, are investigated. Aldehyde oxidase was partially purified from liver homogenates of mature male guinea pigs by heat treatment and ammonium sulphate precipitation. The total extract was obtained by macerating the aerial parts of R. graveolens in MeOH 70% and the effect of this extract on the enzyme activity was assayed using phenanthridine, vanillin and benzaldehyde as substrates. Quercetin and its glycoside form, rutin were isolated, purified and identified from the extract and their inhibitory effects on the enzyme were investigated. R. graveolens extract exhibited a high inhibition on aldehyde oxidase activity (89-96%) at 100 microg/ml which was comparable with 10 microM of menadione, a specific potent inhibitor of aldehyde oxidase. The IC50 values for the inhibitory effect of extract against the oxidation of benzaldehyde, vanillin and phenanthridine were 10.4, 10.1, 43.2 microg/ml, respectively. Both quercetin and rutin at 10 microM caused 70-96% and 27-52% inhibition on the enzyme activity, respectively. Quercetin was more potent inhibitor than rutin, but both flavonols exerted their inhibitory effects mostly in a linear mixed-type.

  10. Effect of different solvent on the photocatalytic activity of ZnIn2S4 for selective oxidation of aromatic alcohols to aromatic aldehydes under visible light irradiation

    Science.gov (United States)

    Su, Li; Ye, Xiangju; Meng, Sugang; Fu, Xianliang; Chen, Shifu

    2016-10-01

    A series of ternary chalcogenides, zinc indium sulphide (ZnIn2S4), were synthesized by a simple solvothermal method with different solvents. The structure, textural, and optical properties of the resulting materials were thoroughly characterized by several techniques. The as-prepared ZnIn2S4 samples could all be employed as excellent photocatalysts to activate O2 for selective oxidation of aromatic alcohols to aromatic aldehydes under visible light illumination. The results showed that ZnIn2S4 prepared in ethanol solvent (ZIS-EtOH) exhibited the highest photocatalytic activity among the screened samples. The differences of photocatalytic performance for ZnIn2S4 samples prepared in different media were mainly attributed to the different levels of exposed {0001} special facets caused by the exposure extent of the basic crystal plane. In addition, rad O2- and positive holes were proved to be the main active species during the photocatalytic process. Combined with the previous reports, a possible photocatalytic mechanism for the selective oxidation of benzyl alcohol to benzaldehyde over ZnIn2S4 sample was proposed.

  11. A coniferyl aldehyde dehydrogenase gene from Pseudomonas sp. strain HR199 enhances the conversion of coniferyl aldehyde by Saccharomyces cerevisiae.

    Science.gov (United States)

    Adeboye, Peter Temitope; Olsson, Lisbeth; Bettiga, Maurizio

    2016-07-01

    The conversion of coniferyl aldehyde to cinnamic acids by Saccharomyces cerevisiae under aerobic growth conditions was previously observed. Bacteria such as Pseudomonas have been shown to harbor specialized enzymes for converting coniferyl aldehyde but no comparable enzymes have been identified in S. cerevisiae. CALDH from Pseudomonas was expressed in S. cerevisiae. An acetaldehyde dehydrogenase (Ald5) was also hypothesized to be actively involved in the conversion of coniferyl aldehyde under aerobic growth conditions in S. cerevisiae. In a second S. cerevisiae strain, the acetaldehyde dehydrogenase (ALD5) was deleted. A prototrophic control strain was also engineered. The engineered S. cerevisiae strains were cultivated in the presence of 1.1mM coniferyl aldehyde under aerobic condition in bioreactors. The results confirmed that expression of CALDH increased endogenous conversion of coniferyl aldehyde in S. cerevisiae and ALD5 is actively involved with the conversion of coniferyl aldehyde in S. cerevisiae. PMID:27070284

  12. Protein film photoelectrochemistry of the water oxidation enzyme photosystem II.

    Science.gov (United States)

    Kato, Masaru; Zhang, Jenny Z; Paul, Nicholas; Reisner, Erwin

    2014-09-21

    Photosynthesis is responsible for the sunlight-powered conversion of carbon dioxide and water into chemical energy in the form of carbohydrates and the release of O2 as a by-product. Although many proteins are involved in photosynthesis, the fascinating machinery of Photosystem II (PSII) is at the heart of this process. This tutorial review describes an emerging technique named protein film photoelectrochemistry (PF-PEC), which allows for the light-dependent activity of PSII adsorbed onto an electrode surface to be studied. The technique is straightforward to use, does not require highly specialised and/or expensive equipment, is highly selective for the active fractions of the adsorbed enzyme, and requires a small amount of enzyme sample. The use of PF-PEC to study PSII can yield insights into its activity, stability, quantum yields, redox behaviour, and interfacial electron transfer pathways. It can also be used in PSII inhibition studies and chemical screening, which may prove useful in the development of biosensors. PSII PF-PEC cells also serve as proof-of-principle solar water oxidation systems; here, a comparison is made against PSII-inspired synthetic photocatalysts and materials for artificial photosynthesis.

  13. Effect of commonly used organic solvents on aldehyde oxidase-mediated vanillin, phthalazine and methotrexate oxidation in human, rat and mouse liver subcellular fractions.

    Science.gov (United States)

    Behera, Dayanidhi; Pattem, Rambabu; Gudi, Girish

    2014-08-01

    1. Aldehyde oxidase (AOX) is a cytosolic molybdoflavoprotein enzyme widely distributed across many tissues. In this study, we report the effect of commonly used organic solvents such as dimethyl sulfoxide (DMSO), acetonitrile (ACN), methanol and ethanol on AOX activity in human, rat and mouse liver S9 fractions using vanillin, phthalazine and methotrexate as probe substrates. 2. Methanol was found to be the most potent solvent in inhibiting vanillic acid and 1-phthalazinone formation in comparison to DMSO, ACN and ethanol across the species tested, except 7-hydroxy methotrexate. 3. Treatment with these solvents at approximate IC50 (% v/v) concentrations showed significant reduction in Clint and Vmax of the probe substrates and also resulted in different effects on Km across the species. 4. Marked differences in the activity and affinity towards AOX were observed with different probe substrates with methotrexate showing least activity and affinity as compared to vanillin and phthalazine. 5. Overall, AOX activity seemed to be more resilient to the presence of organic solvents at higher concentrations in human and rodent species. These results suggest that low concentrations of organic solvents are acceptable for in vitro incubations involving AOX-mediated metabolism.

  14. Synthesis of 5'-Aldehyde Oligonucleotide.

    Science.gov (United States)

    Lartia, Rémy

    2016-01-01

    Synthesis of oligonucleotide ending with an aldehyde functional group at their 5'-end (5'-AON) is possible for both DNA (5'-AODN) and RNA (5'-AORN) series irrespectively of the nature of the last nucleobase. The 5'-alcohol of on-support ODN is mildly oxidized under Moffat conditions. Transient protection of the resulting aldehyde by N,N'-diphenylethylenediamine derivatives allows cleavage, deprotection, and RP-HPLC purification of the protected 5'-AON. Finally, 5'-AON is deprotected by usual acetic acid treatment. In the aggregates, 5'-AON can be now synthesized and purified as routinely as non-modified ODNs, following procedures similar to the well-known "DMT-On" strategy. PMID:26967469

  15. Quantification of the 2-deoxyribonolactone and nucleoside 5'-aldehyde products of 2-deoxyribose oxidation in DNA and cells by isotope-dilution gas chromatography mass spectrometry: differential effects of gamma-radiation and Fe2+-EDTA.

    Science.gov (United States)

    Chan, Wan; Chen, Bingzi; Wang, Lianrong; Taghizadeh, Koli; Demott, Michael S; Dedon, Peter C

    2010-05-01

    The oxidation of 2-deoxyribose in DNA has emerged as a critical determinant of the cellular toxicity of oxidative damage to DNA, with oxidation of each carbon producing a unique spectrum of electrophilic products. We have developed and validated an isotope-dilution gas chromatography-coupled mass spectrometry (GC-MS) method for the rigorous quantification of two major 2-deoxyribose oxidation products: the 2-deoxyribonolactone abasic site of 1'-oxidation and the nucleoside 5'-aldehyde of 5'-oxidation chemistry. The method entails elimination of these products as 5-methylene-2(5H)-furanone (5MF) and furfural, respectively, followed by derivatization with pentafluorophenylhydrazine (PFPH), addition of isotopically labeled PFPH derivatives as internal standards, extraction of the derivatives, and quantification by GC-MS analysis. The precision and accuracy of the method were validated with oligodeoxynucleotides containing the 2-deoxyribonolactone and nucleoside 5'-aldehyde lesions. Further, the well-defined 2-deoxyribose oxidation chemistry of the enediyne antibiotics, neocarzinostatin and calicheamicin gamma(1)(I), was exploited in control studies, with neocarzinostatin producing 10 2-deoxyribonolactone and 300 nucleoside 5'-aldehyde per 10(6) nt per microM in accord with its established minor 1'- and major 5'-oxidation chemistry. Calicheamicin unexpectedly caused 1'-oxidation at a low level of 10 2-deoxyribonolactone per 10(6) nt per microM in addition to the expected predominance of 5'-oxidation at 560 nucleoside 5'-aldehyde per 10(6) nt per microM. The two hydroxyl radical-mediated DNA oxidants, gamma-radiation and Fe(2+)-EDTA, produced nucleoside 5'-aldehyde at a frequency of 57 per 10(6) nt per Gy (G-value 74 nmol/J) and 3.5 per 10(6) nt per microM, respectively, which amounted to 40% and 35%, respectively, of total 2-deoxyribose oxidation as measured by a plasmid nicking assay. However, gamma-radiation and Fe(2+)-EDTA produced different proportions of 2

  16. Fatty Aldehyde and Fatty Alcohol Metabolism: Review and Importance for Epidermal Structure and Function

    OpenAIRE

    Rizzo, William B.

    2013-01-01

    Normal fatty aldehyde and alcohol metabolism is essential for epidermal differentiation and function. Long-chain aldehydes are produced by catabolism of several lipids including fatty alcohols, sphingolipids, ether glycerolipids, isoprenoid alcohols and certain aliphatic lipids that undergo α- or ω-oxidation. The fatty aldehyde generated by these pathways is chiefly metabolized to fatty acid by fatty aldehyde dehydrogenase (FALDH, alternately known as ALDH3A2), which also functions to oxidize...

  17. Sorption Behavior of an Aliphatic Series of Aldehydes in the Presence of Poly(ethylene terephthalate) Blends Containing Aldehyde Scavenging Agents

    OpenAIRE

    Suloff, Eric Charles

    2002-01-01

    The quality of many beverages and food products is compromised by the presence of low molecular weight aldehydes. Aldehydes are commonly formed during storage by the oxidation of lipids or are introduced as migrants from polymeric packaging material. The objective of this project was to evaluate the effectiveness of three aldehyde scavenging agents, blended into poly(ethylene terephthalate) (PET) films, in removing an aliphatic series of aldehydes from an acidified aqueous model solution (p...

  18. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  19. The ORF slr0091 of Synechocystis sp. PCC6803 encodes a high-light induced aldehyde dehydrogenase converting apocarotenals and alkanals

    KAUST Repository

    Trautmann, Danika

    2013-07-05

    Oxidative cleavage of carotenoids and peroxidation of lipids lead to apocarotenals and aliphatic aldehydes called alkanals, which react with vitally important compounds, promoting cytotoxicity. Although many enzymes have been reported to deactivate alkanals by converting them into fatty acids, little is known about the mechanisms used to detoxify apocarotenals or the enzymes acting on them. Cyanobacteria and other photosynthetic organisms must cope with both classes of aldehydes. Here we report that the Synechocystis enzyme SynAlh1, encoded by the ORF slr0091, is an aldehyde dehydrogenase that mediates oxidation of both apocarotenals and alkanals into the corresponding acids. Using a crude lysate of SynAlh1-expressing Escherichia coli cells, we show that SynAlh1 converts a wide range of apocarotenals and alkanals, with a preference for apocarotenals with defined chain lengths. As suggested by in vitro incubations and using engineered retinal-forming E. coli cells, we found that retinal is not a substrate for SynAlh1, making involvement in Synechocystis retinoid metabolism unlikely. The transcript level of SynAlh1 is induced by high light and cold treatment, indicating a role in the stress response, and the corresponding gene is a constituent of a stress-related operon. The assumptions regarding the function of SynAlh are further supported by the surprisingly high homology to human and plant aldehyde dehydrogenase that have been assigned to aldehyde detoxification. SynAlh1 is the first aldehyde dehydrogenase that has been shown to form both apocarotenoic and fatty acids. This dual function suggests that its eukaryotic homologs may also be involved in apocarotenal metabolism, a function that has not been considered so far. Aldehyde dehydrogenases play an important role in detoxification of reactive aldehydes. Here, we report on a cyanbacterial enzyme capable in converting two classes of lipid-derived aldehydes, apocaotenals and alkanals. The corresponding gene is a

  20. Detoxifying Enzymes at the Cross-Roads of Inflammation, Oxidative Stress, and Drug Hypersensitivity: Role of Glutathione Transferase P1-1 and Aldose Reductase.

    Science.gov (United States)

    Sánchez-Gómez, Francisco J; Díez-Dacal, Beatriz; García-Martín, Elena; Agúndez, José A G; Pajares, María A; Pérez-Sala, Dolores

    2016-01-01

    Phase I and II enzymes are involved in the metabolism of endogenous reactive compounds as well as xenobiotics, including toxicants and drugs. Genotyping studies have established several drug metabolizing enzymes as markers for risk of drug hypersensitivity. However, other candidates are emerging that are involved in drug metabolism but also in the generation of danger or costimulatory signals. Enzymes such as aldo-keto reductases (AKR) and glutathione transferases (GST) metabolize prostaglandins and reactive aldehydes with proinflammatory activity, as well as drugs and/or their reactive metabolites. In addition, their metabolic activity can have important consequences for the cellular redox status, and impacts the inflammatory response as well as the balance of inflammatory mediators, which can modulate epigenetic factors and cooperate or interfere with drug-adduct formation. These enzymes are, in turn, targets for covalent modification and regulation by oxidative stress, inflammatory mediators, and drugs. Therefore, they constitute a platform for a complex set of interactions involving drug metabolism, protein haptenation, modulation of the inflammatory response, and/or generation of danger signals with implications in drug hypersensitivity reactions. Moreover, increasing evidence supports their involvement in allergic processes. Here, we will focus on GSTP1-1 and aldose reductase (AKR1B1) and provide a perspective for their involvement in drug hypersensitivity. PMID:27540362

  1. Methane-Oxidizing Enzymes: An Upstream Problem in Biological Gas-to-Liquids Conversion.

    Science.gov (United States)

    Lawton, Thomas J; Rosenzweig, Amy C

    2016-08-01

    Biological conversion of natural gas to liquids (Bio-GTL) represents an immense economic opportunity. In nature, aerobic methanotrophic bacteria and anaerobic archaea are able to selectively oxidize methane using methane monooxygenase (MMO) and methyl coenzyme M reductase (MCR) enzymes. Although significant progress has been made toward genetically manipulating these organisms for biotechnological applications, the enzymes themselves are slow, complex, and not recombinantly tractable in traditional industrial hosts. With turnover numbers of 0.16-13 s(-1), these enzymes pose a considerable upstream problem in the biological production of fuels or chemicals from methane. Methane oxidation enzymes will need to be engineered to be faster to enable high volumetric productivities; however, efforts to do so and to engineer simpler enzymes have been minimally successful. Moreover, known methane-oxidizing enzymes have different expression levels, carbon and energy efficiencies, require auxiliary systems for biosynthesis and function, and vary considerably in terms of complexity and reductant requirements. The pros and cons of using each methane-oxidizing enzyme for Bio-GTL are considered in detail. The future for these enzymes is bright, but a renewed focus on studying them will be critical to the successful development of biological processes that utilize methane as a feedstock. PMID:27366961

  2. Enzyme phylogenies as markers for the oxidation state of the environment: The case of respiratory arsenate reductase and related enzymes

    Directory of Open Access Journals (Sweden)

    Schoepp-Cothenet Barbara

    2008-07-01

    Full Text Available Abstract Background Phylogenies of certain bioenergetic enzymes have proved to be useful tools for deducing evolutionary ancestry of bioenergetic pathways and their relationship to geochemical parameters of the environment. Our previous phylogenetic analysis of arsenite oxidase, the molybdopterin enzyme responsible for the biological oxidation of arsenite to arsenate, indicated its probable emergence prior to the Archaea/Bacteria split more than 3 billion years ago, in line with the geochemical fact that arsenite was present in biological habitats on the early Earth. Respiratory arsenate reductase (Arr, another molybdopterin enzyme involved in microbial arsenic metabolism, serves as terminal oxidase, and is thus situated at the opposite end of bioenergetic electron transfer chains as compared to arsenite oxidase. The evolutionary history of the Arr-enzyme has not been studied in detail so far. Results We performed a genomic search of genes related to arrA coding for the molybdopterin subunit. The multiple alignment of the retrieved sequences served to reconstruct a neighbor-joining phylogeny of Arr and closely related enzymes. Our analysis confirmed the previously proposed proximity of Arr to the cluster of polysulfide/thiosulfate reductases but also unravels a hitherto unrecognized clade even more closely related to Arr. The obtained phylogeny strongly suggests that Arr originated after the Bacteria/Archaea divergence in the domain Bacteria, and was subsequently laterally distributed within this domain. It further more indicates that, as a result of accumulation of arsenate in the environment, an enzyme related to polysulfide reductase and not to arsenite oxidase has evolved into Arr. Conclusion These findings are paleogeochemically rationalized by the fact that the accumulation of arsenate over arsenite required the increase in oxidation state of the environment brought about by oxygenic photosynthesis.

  3. Oligomerization and hydroxylation of green tea catechins by oxidative enzymes

    NARCIS (Netherlands)

    Verloop, J.W.

    2016-01-01

    Black teas are known for their characteristic brown colour, bitter taste and astringent mouth feel. These sensory characteristics are mainly influenced by the phenolic oxidation products present in black tea. The oxidation of phenolics from green tea leaves during black tea manufacturing is an uncon

  4. Detoxification of aldehydes by histidine-containing dipeptides: from chemistry to clinical implications

    OpenAIRE

    Xie, Zhengzhi; Baba, Shahid P.; Sweeney, Brooke R.; Barski, Oleg A.

    2013-01-01

    Aldehydes are generated by oxidized lipids and carbohydrates at increased levels under conditions of metabolic imbalance and oxidative stress during atherosclerosis, myocardial and cerebral ischemia, diabetes, neurodegenerative diseases and trauma. In most tissues, aldehydes are detoxified by oxidoreductases that catalyze the oxidation or the reduction of aldehydes or enzymatic and nonenzymatic conjugation with low molecular weight thiols and amines, such as glutathione and histidine dipeptid...

  5. Oxidative bioelectrocatalysis: From natural metabolic pathways to synthetic metabolons and minimal enzyme cascades.

    Science.gov (United States)

    Minteer, Shelley D

    2016-05-01

    Anodic bioelectrodes for biofuel cells are more complex than cathodic bioelectrodes for biofuel cells, because laccase and bilirubin oxidase can individually catalyze four electron reduction of oxygen to water, whereas most anodic enzymes only do a single two electron oxidation of a complex fuel (i.e. glucose oxidase oxidizing glucose to gluconolactone while generating 2 electrons of the total 24 electrons), so enzyme cascades are typically needed for complete oxidation of the fuel. This review article will discuss the lessons learned from natural metabolic pathways about multi-step oxidation and how those lessons have been applied to minimal or artificial enzyme cascades. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  6. Is Liver Enzyme Release Really Associated with Cell Necrosis Induced by Oxidant Stress?

    Directory of Open Access Journals (Sweden)

    Martha Lucinda Contreras-Zentella

    2016-01-01

    Full Text Available Hepatic diseases are a major concern worldwide. Increased specific plasma enzyme activities are considered diagnostic features for liver diseases, since enzymes are released into the blood compartment following the deterioration of the organ. Release of liver mitochondrial enzymes is considered strong evidence for hepatic necrosis, which is associated with an increased production of ROS, often leading to greater hepatic lipid peroxidation. Lipotoxic mediators and intracellular signals activated Kupffer cells, which provides evidence strongly suggesting the participation of oxidant stress in acute liver damage, inducing the progression of liver injury to chronic liver damage. Elevated transaminase activities are considered as an index marker of hepatotoxicity, linked to oxidant stress. However, a drastic increase of serum activities of liver enzyme markers ought not necessarily to reflect liver cell death. In fact, increased serum levels of cytoplasmic enzymes have readily been observed after partial hepatectomy (PH in the regenerating liver of rats. In this regard, we are now showing that in vitro modifications of the oxidant status affect differentially the release of liver enzymes, indicating that this release is a strictly controlled event and not directly related to the onset of oxidant stress of the liver.

  7. Is Liver Enzyme Release Really Associated with Cell Necrosis Induced by Oxidant Stress?

    Science.gov (United States)

    Contreras-Zentella, Martha Lucinda; Hernández-Muñoz, Rolando

    2016-01-01

    Hepatic diseases are a major concern worldwide. Increased specific plasma enzyme activities are considered diagnostic features for liver diseases, since enzymes are released into the blood compartment following the deterioration of the organ. Release of liver mitochondrial enzymes is considered strong evidence for hepatic necrosis, which is associated with an increased production of ROS, often leading to greater hepatic lipid peroxidation. Lipotoxic mediators and intracellular signals activated Kupffer cells, which provides evidence strongly suggesting the participation of oxidant stress in acute liver damage, inducing the progression of liver injury to chronic liver damage. Elevated transaminase activities are considered as an index marker of hepatotoxicity, linked to oxidant stress. However, a drastic increase of serum activities of liver enzyme markers ought not necessarily to reflect liver cell death. In fact, increased serum levels of cytoplasmic enzymes have readily been observed after partial hepatectomy (PH) in the regenerating liver of rats. In this regard, we are now showing that in vitro modifications of the oxidant status affect differentially the release of liver enzymes, indicating that this release is a strictly controlled event and not directly related to the onset of oxidant stress of the liver.

  8. Simultaneous involvement of a tungsten-containing aldehyde:ferredoxin oxidoreductase and a phenylacetaldehyde dehydrogenase in anaerobic phenylalanine metabolism.

    Science.gov (United States)

    Debnar-Daumler, Carlotta; Seubert, Andreas; Schmitt, Georg; Heider, Johann

    2014-01-01

    Anaerobic phenylalanine metabolism in the denitrifying betaproteobacterium Aromatoleum aromaticum is initiated by conversion of phenylalanine to phenylacetate, which is further metabolized via benzoyl-coenzyme A (CoA). The formation of phenylacetate is catalyzed by phenylalanine transaminase, phenylpyruvate decarboxylase, and a phenylacetaldehyde-oxidizing enzyme. The presence of these enzymes was detected in extracts of cells grown with phenylalanine and nitrate. We found that two distinct enzymes are involved in the oxidation of phenylacetaldehyde to phenylacetate, an aldehyde:ferredoxin oxidoreductase (AOR) and a phenylacetaldehyde dehydrogenase (PDH). Based on sequence comparison, growth studies with various tungstate concentrations, and metal analysis of the enriched enzyme, AOR was shown to be a tungsten-containing enzyme, necessitating specific cofactor biosynthetic pathways for molybdenum- and tungsten-dependent enzymes simultaneously. We predict from the genome sequence that most enzymes of molybdopterin biosynthesis are shared, while the molybdate/tungstate uptake systems are duplicated and specialized paralogs of the sulfur-inserting MoaD and the metal-inserting MoeA proteins seem to be involved in dedicating biosynthesis toward molybdenum or tungsten cofactors. We also characterized PDH biochemically and identified both NAD(+) and NADP(+) as electron acceptors. We identified the gene coding for the enzyme and purified a recombinant Strep-tagged PDH variant. The homotetrameric enzyme is highly specific for phenylacetaldehyde, has cooperative kinetics toward the substrate, and shows considerable substrate inhibition. Our data suggest that A. aromaticum utilizes PDH as the primary enzyme during anaerobic phenylalanine degradation, whereas AOR is not essential for the metabolic pathway. We hypothesize a function as a detoxifying enzyme if high aldehyde concentrations accumulate in the cytoplasm, which would lead to substrate inhibition of PDH.

  9. Effect of Pimpinellatirupatiensison Oxidative Enzymes in STZ-induced Diabetic Rat Kidney

    OpenAIRE

    RajeswaraReddy, Saddala; Lavany, Thopireddy; Narasimhulu, Ganapathi; SathyaveluReddy, Kesireddy

    2012-01-01

    The present study was aimed to evaluate the therapeutic potential of Pimpinellatirupatiensis(Pt) by assaying the activities of selective mitochondrial enzymes in streptozotocin induced diabetic rats. Diabetic rats showed a significant (p < 0.01) reduction in the activities of oxidative enzymes Succinate dehydrogenase (SDH), Malate dehydrogenase (MDH), Glutamate dehydrogenase (GDH) and isocitrate dehydrogenase (ICDH). Lactate dehydrogenase (LDH) activity was significantly (p < 0.01) increased ...

  10. Lipid Peroxidation, Antioxidant Enzymes and Levels of Nitric Oxide in Sheep Infected with Fasciola hepatica

    OpenAIRE

    BENZER, Fulya; OZAN, Sema TEMİZER

    2003-01-01

    In this study, the levels of malondialdehyde and activities of catalase and glutathione peroxidase, two antioxidant enzymes, and the levels of nitric oxide in sheep infected with Fasciola hepatica were measured. The level of malondialdehyde in plasma and tissue was measured according to the Yagi and Ohkawa methods, respectively. The activities of catalase and glutathione peroxidase were measured according to the methods of Aebi and Beutler, respectively. The level of nitric oxide was deter...

  11. Aldehyde oxidase activity in fresh human skin.

    Science.gov (United States)

    Manevski, Nenad; Balavenkatraman, Kamal Kumar; Bertschi, Barbara; Swart, Piet; Walles, Markus; Camenisch, Gian; Schiller, Hilmar; Kretz, Olivier; Ling, Barbara; Wettstein, Reto; Schaefer, Dirk J; Pognan, Francois; Wolf, Armin; Litherland, Karine

    2014-12-01

    Human aldehyde oxidase (AO) is a molybdoflavoenzyme that commonly oxidizes azaheterocycles in therapeutic drugs. Although high metabolic clearance by AO resulted in several drug failures, existing in vitro-in vivo correlations are often poor and the extrahepatic role of AO practically unknown. This study investigated enzymatic activity of AO in fresh human skin, the largest organ of the body, frequently exposed to therapeutic drugs and xenobiotics. Fresh, full-thickness human skin was obtained from 13 individual donors and assayed with two specific AO substrates: carbazeran and zoniporide. Human skin explants from all donors metabolized carbazeran to 4-hydroxycarbazeran and zoniporide to 2-oxo-zoniporide. Average rates of carbazeran and zoniporide hydroxylations were 1.301 and 0.164 pmol⋅mg skin(-1)⋅h(-1), resulting in 13 and 2% substrate turnover, respectively, after 24 hours of incubation with 10 μM substrate. Hydroxylation activities for the two substrates were significantly correlated (r(2) = 0.769), with interindividual variability ranging from 3-fold (zoniporide) to 6-fold (carbazeran). Inclusion of hydralazine, an irreversible inhibitor of AO, resulted in concentration-dependent decrease of hydroxylation activities, exceeding 90% inhibition of carbazeran 4-hydroxylation at 100 μM inhibitor. Reaction rates were linear up to 4 hours and well described by Michaelis-Menten enzyme kinetics. Comparison of carbazeran and zoniporide hydroxylation with rates of triclosan glucuronidation and sulfation and p-toluidine N-acetylation showed that cutaneous AO activity is comparable to tested phase II metabolic reactions, indicating a significant role of AO in cutaneous drug metabolism. To our best knowledge, this is the first report of AO enzymatic activity in human skin. PMID:25249692

  12. Air pollution source apportionment before, during, and after the 2008 Beijing Olympics and association of sources to aldehydes and biomarkers of blood coagulation, pulmonary and systemic inflammation, and oxidative stress in healthy young adults

    Science.gov (United States)

    Altemose, Brent A.

    Based on principal component analysis (PCA) of air pollution data collected during the Summer Olympic Games held in Beijing, China during 2008, the five source types of air pollution identified -- natural soil/road dust, vehicle and industrial combustion, vegetative burning, oil combustion, and secondary formation, were all distinctly lower during the Olympics. This was particularly true for vehicle and industrial combustion and oil combustion, and during the main games period between the opening and closing ceremonies. The reduction in secondary formation was reflective of a reduction in nitrogen oxides, but this also contributed to increased ozone concentrations during the Olympic period. Among three toxic aldehydes measured in Beijing during the same time period, only acetaldehyde had a reduction in mean concentration during the Olympic air pollution control period compared to the pre-Olympic period. Accordingly, acetaldehyde was significantly correlated with primary emission sources including vegetative burning and oil combustion, and with several pollutants emitted mainly from primary sources. In contrast, formaldehyde and acrolein increased during the Olympic air pollution control period; accordingly both were significantly correlated with ozone and with the secondary formation source type. These findings indicate primary sources may dominate for acetaldehyde while secondary sources may dominate for formaldehyde and acrolein. Biomarkers for pulmonary inflammation (exhaled breath condensate (EBC) pH, exhaled nitric oxide, and EBC nitrite) and hemostasis and blood coagulation (vWF and sCD62p) were most consistently associated with vehicle and industrial combustion, oil combustion, and vegetative burning. The systemic inflammation biomarker 8-OHdG was most consistently associated with vehicle and industrial combustion. In contrast, the associations between the biomarkers and the aldehydes were generally not significant or in the hypothesized direction, although

  13. Mitochondrial targeting of bilirubin regulatory enzymes: An adaptive response to oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Muhsain, Siti Nur Fadzilah, E-mail: sitinurfadzilah077@ppinang.uitm.edu.my [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Faculty of Pharmacy, University Teknologi Mara (Malaysia); Lang, Matti A., E-mail: m.lang@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)

    2015-01-01

    The intracellular level of bilirubin (BR), an endogenous antioxidant that is cytotoxic at high concentrations, is tightly controlled within the optimal therapeutic range. We have recently described a concerted intracellular BR regulation by two microsomal enzymes: heme oxygenase 1 (HMOX1), essential for BR production and cytochrome P450 2A5 (CYP2A5), a BR oxidase. Herein, we describe targeting of these enzymes to hepatic mitochondria during oxidative stress. The kinetics of microsomal and mitochondrial BR oxidation were compared. Treatment of DBA/2J mice with 200 mg pyrazole/kg/day for 3 days increased hepatic intracellular protein carbonyl content and induced nucleo-translocation of Nrf2. HMOX1 and CYP2A5 proteins and activities were elevated in microsomes and mitoplasts but not the UGT1A1, a catalyst of BR glucuronidation. A CYP2A5 antibody inhibited 75% of microsomal BR oxidation. The inhibition was absent in control mitoplasts but elevated to 50% after treatment. An adrenodoxin reductase antibody did not inhibit microsomal BR oxidation but inhibited 50% of mitochondrial BR oxidation. Ascorbic acid inhibited 5% and 22% of the reaction in control and treated microsomes, respectively. In control mitoplasts the inhibition was 100%, which was reduced to 50% after treatment. Bilirubin affinity to mitochondrial and microsomal CYP2A5 enzyme is equally high. Lastly, the treatment neither released cytochrome c into cytoplasm nor dissipated membrane potential, indicating the absence of mitochondrial membrane damage. Collectively, the observations suggest that BR regulatory enzymes are recruited to mitochondria during oxidative stress and BR oxidation by mitochondrial CYP2A5 is supported by mitochondrial mono-oxygenase system. The induced recruitment potentially confers membrane protection. - Highlights: • Pyrazole induces oxidative stress in the mouse liver. • Pyrazole-induced oxidative stress induces mitochondrial targeting of key bilirubin regulatory enzymes, HMOX1

  14. Star block-copolymers: Enzyme-inspired catalysts for oxidation of alcohols in water

    KAUST Repository

    Mugemana, Clement

    2014-01-01

    A number of fluorous amphiphilic star block-copolymers containing a tris(benzyltriazolylmethyl)amine motif have been prepared. These polymers assembled into well-defined nanostructures in water, and their mode of assembly could be controlled by changing the composition of the polymer. The polymers were used for enzyme-inspired catalysis of alcohol oxidation. This journal is © the Partner Organisations 2014.

  15. [Photodynamic reaction and oxidative stress - influence of the photodynamic effect on the activity antioxidant enzymes].

    Science.gov (United States)

    Romiszewska, Anna; Nowak-Stępniowska, Agata

    2014-01-01

    The interaction of light with a photosensitizer, accumulated in a tissue in the presence of oxygen, leads to formation of reactive oxygen species, mainly of singlet oxygen and free radicals. These factors react with biomolecules producing their oxidized states. Reactive oxygen species, such as singlet oxygen and free radicals are able to damage membranes, DNA, enzymes, structural peptides and other cellular structures leading to cell death. An antioxidant protection of cell is formed by enzymes belonging to the family of oxidoreductases: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR). Photodynamic therapy leads to the increased production of oxidizing toxic forms. It is important to analyze impact of PDT on the activity of antioxidant enzymes, such as SOD, CAT, GPx. The activity of antioxidant enzymes during the photodynamic effect is influenced by both the light energy dose and the concentration of photosensitizer. The presence only of the photosensitizer or only the light energy may also result in changes in the activity of these enzymes. The differences in changes in the activity of these enzymes depend on the type of used photosensitizer. A phenomenon of selective accumulation of photosensitizer in tumor tissues is used in the photodynamic method of tumor diagnosis and treatment.

  16. Stabilization of oil-in-water emulsions by enzyme catalyzed oxidative gelation of sugar beet pectin

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz; Chronakis, Ioannis S.; Meyer, Anne S.

    2013-01-01

    larger average particle sizes than the emulsions in which the SBP was homogenized into the emulsion system during emulsion preparation (referred as Mix B). Mix B type emulsions were stable. Enzyme catalyzed oxidative gelation of SBP helped stabilize the emulsions in Mix A. The kinetics of the enzyme...... catalyzed oxidative gelation of SBP was evaluated by small angle oscillatory measurements for horseradish peroxidase (HRP) (EC 1.11.1.7) and laccase (EC 1.10.3.2) catalysis, respectively. HRP catalyzed gelation rates, determined from the slopes of the increase of elastic modulus (G0) with time, were higher......, and higher stress was needed to break the gels in Mix A than in Mix B at similar enzyme dosage levels. These ifferences may be related to a lower availability of the feruloyl groups for cross-linking when the SBP was homogenized into the emulsion system during preparation....

  17. Fracturing Fluid (Guar Polymer Gel Degradation Study by using Oxidative and Enzyme Breaker

    Directory of Open Access Journals (Sweden)

    Aung Kyaw

    2012-06-01

    Full Text Available Oxidative and enzyme breakers are used in this research project with the main objective to study on the degradation pattern of fracturing fluid (i.e., guar polymer gel as a function of time, temperature and breaker concentration itself. The fracturing fluid used in hydraulic fracturing or frac pack contain a chemical breakers to reduce the viscosity of the fluid intermingled with the proppant. Chemical breakers reduce viscosity of the guar polymer by cleaving the polymer into small-molecular-weight fragments. The reduction of viscosity will facilitate the flow-back of residual polymer providing rapid recovery of polymer from proppant pack. Ineffective breakers or misapplication of breakers can result in screen-outs or flow-back of viscous fluids both of which can significantly decrease the well productivity. Breaker activity of low to medium temperature range oxidative and enzyme breaker systems was evaluated. ViCon NF an oxidative breaker (Halliburton product and GBW 12- CD an enzyme breaker (BJ Services product were used in this research project with the main objective to study on the degradation pattern of fracturing fluid (guar polymer gel as a function of (time, temperature and breaker concentration itself. This study provides focuses on the way to mix the fracturing fluid, compositions of the fracturing fluid and how to conduct the crosslink and break test. Crosslink test indicate the optimum cross-linker concentration to produce good crosslink gel and the break test gave the characteristic of the gel during degradation process and also the break time. Besides relying on the laboratory experiment, information obtained from research on SPE and US Pattern papers were used to make a comparison study on oxidative and enzyme breakers properties. Degradation pattern observed from the break test showed that reduction in gel viscosity depends on time, temperature and breaker concentration. Observations from experiment also revealed that small

  18. Serum Antioxidative Enzymes Levels and Oxidative Stress Products in Age-Related Cataract Patients

    Science.gov (United States)

    Chang, Dong; Zhang, Xuefei; Rong, Shengzhong; Sha, Qian; Liu, Peipei; Han, Tao; Pan, Hongzhi

    2013-01-01

    Purpose. To investigate the activity of antioxidative enzymes and the products of oxidative stress in patients with age-related cataracts and compare the findings with those in healthy control subjects. Method. Sixty patients with age-related cataract and sixty healthy controls of matched age and gender were included in this study. Serum samples were obtained to detect the antioxidative enzymes of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and oxidation degradation products of malondialdehyde (MDA), 4-hydroxynonenal (4-HNE), conjugated diene (CD), advanced oxidation protein products (AOPP), protein carbonyl (PC), and 8-hydroxydeoxyguanosine (8-OHdG). Results. Serum SOD, GSH-Px, and CAT activities in cataract group were significantly decreased as compared to the control subjects (P < 0.05). The levels of MDA, 4-HNE, and CD in cataract patients were significantly higher than those in the control subjects (P < 0.05, P < 0.01). Cataract patients had higher levels of 8-OHdG, AOPP, and PC with respect to the comparative group of normal subjects (P < 0.01). And there was no statistical significance in concentration of antioxidative enzymes and oxidative stress products in patients with different subtype cataract. Conclusions. Oxidative stress is an important risk factor in the development of age-related cataract, and augmentation of the antioxidant defence systems may be of benefit to prevent or delay cataractogenesis. PMID:23781296

  19. Serum Antioxidative Enzymes Levels and Oxidative Stress Products in Age-Related Cataract Patients

    Directory of Open Access Journals (Sweden)

    Dong Chang

    2013-01-01

    Full Text Available Purpose. To investigate the activity of antioxidative enzymes and the products of oxidative stress in patients with age-related cataracts and compare the findings with those in healthy control subjects. Method. Sixty patients with age-related cataract and sixty healthy controls of matched age and gender were included in this study. Serum samples were obtained to detect the antioxidative enzymes of superoxide dismutase (SOD, catalase (CAT, and glutathione peroxidase (GSH-Px, and oxidation degradation products of malondialdehyde (MDA, 4-hydroxynonenal (4-HNE, conjugated diene (CD, advanced oxidation protein products (AOPP, protein carbonyl (PC, and 8-hydroxydeoxyguanosine (8-OHdG. Results. Serum SOD, GSH-Px, and CAT activities in cataract group were significantly decreased as compared to the control subjects (P<0.05. The levels of MDA, 4-HNE, and CD in cataract patients were significantly higher than those in the control subjects (P<0.05, P<0.01. Cataract patients had higher levels of 8-OHdG, AOPP, and PC with respect to the comparative group of normal subjects (P<0.01. And there was no statistical significance in concentration of antioxidative enzymes and oxidative stress products in patients with different subtype cataract. Conclusions. Oxidative stress is an important risk factor in the development of age-related cataract, and augmentation of the antioxidant defence systems may be of benefit to prevent or delay cataractogenesis.

  20. Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by an enzyme preparation from Zea mays

    Science.gov (United States)

    Reinecke, D. M.; Bandurski, R. S.

    1988-01-01

    Indole-3-acetic acid is oxidized to oxindole-3-acetic acid by Zea mays tissue extracts. Shoot, root, and endosperm tissues have enzyme activities of 1 to 10 picomoles per hour per milligram protein. The enzyme is heat labile, is soluble, and requires oxygen for activity. Cofactors of mixed function oxygenase, peroxidase, and intermolecular dioxygenase are not stimulatory to enzymic activity. A heat-stable, detergent-extractable component from corn enhances enzyme activity 6- to 10-fold. This is the first demonstration of the in vitro enzymic oxidation of indole-3-acetic acid to oxindole-3-acetic acid in higher plants.

  1. Structure and Mechanism of ORF36, an Amino Sugar Oxidizing Enzyme in Everninomicin Biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Vey, Jessica L.; Al-Mestarihi, Ahmad; Hu, Yunfeng; Funk, Michael A.; Bachmann, Brian O.; Iverson, T.M. (Vanderbilt)

    2010-12-07

    Everninomicin is a highly modified octasaccharide that belongs to the orthosomycin family of antibiotics and possesses potent Gram-positive antibiotic activity, including broad-spectrum efficacy against multidrug resistant enterococci and Staphylococcus aureus. Among its distinctive structural features is a nitro sugar, L-evernitrose, analogues of which decorate a variety of natural products. Recently, we identified a nitrososynthase enzyme encoded by orf36 from Micromonospora carbonacea var. africana that mediates the flavin-dependent double oxidation of synthetically generated thymidine diphosphate (TDP)-L-epi-vancosamine to the corresponding nitroso sugar. Herein, we utilize a five-enzyme in vitro pathway both to verify that ORF36 catalyzes oxidation of biogenic TDP-L-epi-vancosamine and to determine whether ORF36 exhibits catalytic competence for any of its biosynthetic progenitors, which are candidate substrates for nitrososynthases in vivo. Progenitors solely undergo single-oxidation reactions and terminate in the hydroxylamine oxidation state. Performing the in vitro reactions in the presence of {sup 18}O{sub 2} establishes that molecular oxygen, rather than oxygen from water, is incorporated into ORF36-generated intermediates and products and identifies an off-pathway product that correlates with the oxidation product of a progenitor substrate. The 3.15 {angstrom} resolution X-ray crystal structure of ORF36 reveals a tetrameric enzyme that shares a fold with acyl-CoA dehydrogenases and class D flavin-containing monooxygenases, including the nitrososynthase KijD3. However, ORF36 and KijD3 have unusually open active sites in comparison to these related enzymes. Taken together, these studies map substrate determinants and allow the proposal of a minimal monooxygenase mechanism for amino sugar oxidation by ORF36.

  2. Site-directed mutagenesis of aldehyde dehydrogenase-2 suggests three distinct pathways of nitroglycerin biotransformation.

    Science.gov (United States)

    Wenzl, M Verena; Beretta, Matteo; Griesberger, Martina; Russwurm, Michael; Koesling, Doris; Schmidt, Kurt; Mayer, Bernd; Gorren, Antonius C F

    2011-08-01

    To elucidate the mechanism underlying reduction of nitroglycerin (GTN) to nitric oxide (NO) by mitochondrial aldehyde dehydrogenase (ALDH2), we generated mutants of the enzyme lacking the cysteines adjacent to reactive Cys302 (C301S and C303S), the glutamate that participates as a general base in aldehyde oxidation (E268Q) or combinations of these residues. The mutants were characterized regarding acetaldehyde dehydrogenation, GTN-triggered enzyme inactivation, GTN denitration, NO formation, and soluble guanylate cyclase activation. Lack of the cysteines did not affect dehydrogenase activity but impeded GTN denitration, aggravated GTN-induced enzyme inactivation, and increased NO formation. A triple mutant lacking the cysteines and Glu268 catalyzed sustained formation of superstoichiometric amounts of NO and exhibited slower rates of inactivation. These results suggest three alternative pathways for the reaction of ALDH2 with GTN, all involving formation of a thionitrate/sulfenyl nitrite intermediate at Cys302 as the initial step. In the first pathway, which predominates in the wild-type enzyme and reflects clearance-based GTN denitration, the thionitrate apparently reacts with one of the adjacent cysteine residues to yield nitrite and a protein disulfide. The predominant reaction catalyzed by the single and double cysteine mutants requires Glu268 and results in irreversible enzyme inactivation. Finally, combined lack of the cysteines and Glu268 shifts the reaction toward formation of the free NO radical, presumably through homolytic cleavage of the sulfenyl nitrite intermediate. Although the latter reaction accounts for less than 10% of total turnover of GTN metabolism catalyzed by wild-type ALDH2, it is most likely essential for vascular GTN bioactivation.

  3. Selective Enzymatic Reduction of Aldehydes

    Directory of Open Access Journals (Sweden)

    Patrizia Di Gennaro

    2006-05-01

    Full Text Available Highly selective enzymatic reductions of aldehydes to the corresponding alcohols was performed using an E. coli JM109 whole cell biocatalyst. A selective enzymatic method for the reduction of aldehydes could provide an eco-compatible alternative to chemical methods. The simplicity, fairly wide scope and the very high observed chemoselectivity of this approach are its most unique features.

  4. Evaluation of the mitochondrial respiratory chain and oxidative phosphorylation system using polarography and spectrophotometric enzyme assays.

    Science.gov (United States)

    Barrientos, Antoni; Fontanesi, Flavia; Díaz, Francisca

    2009-10-01

    The oxidative phosphorylation (OXPHOS) system consists of five multimeric complexes embedded in the mitochondrial inner membrane. They work in concert to drive the aerobic synthesis of ATP. Mitochondrial and nuclear DNA mutations affecting the accumulation and function of these enzymes are the most common cause of mitochondrial diseases and have also been associated with neurodegeneration and aging. For this reason, several approaches for the assessment of the OXPHOS system enzymes have been developed. Based on the methods described elsewhere, the assays describe methods that form a biochemical characterization of the OXPHOS system in cells and mitochondria isolated from cultured cells or tissues.

  5. Screening of Enzyme Biomarker for Nanotoxicity of Zinc Oxide in OREOCHROMIS MOSSAMBICUS

    Science.gov (United States)

    Subramanian, Periasamy; Bupesh, Giridharan

    2011-06-01

    Experiments were conducted to determine the effects of Zinc oxide (ZnO) nanoparticles (NPs) on fish models. Oreochromis mossambicus was orally administered with ZnO NPs (50-100 nm) once and its effects at five different concentrations (60 ppm-100 ppm) were observed for 12 days. Enzymatic assays were performed at every three days interval in the vital tissues of liver, gill, muscle and kidney. The defense enzymes, ethoxyresorufin O-deethylase (EROD) and glutathione S transferase (GST) exerted a dose dependent elevation up to 6 days. This hike then declines in higher concentrations and extended duration. Whereas the tissue damaging enzymes, glutamate oxaloacetic transaminase (GOT), glutamate pyruvic transaminase (GPT) and alkaline phosphatase (ALP) as well as the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) exhibited a dose and duration dependent increase until the end of the experiment. Among these enzymes, the antioxidant enzymes response to ZnO NP toxicity on fish showed notable continuous induction. This study demonstrates that antioxidant enzymes responses in O. mossambicus could be used as a biomarker for the early detection of nanotoxicity.

  6. N-nitrosodimethylamine (NDMA, Liver Function Enzymes, Renal Function Parameters and Oxidative Stress Parameters: A Review

    Directory of Open Access Journals (Sweden)

    Usunobun Usunomena

    2012-08-01

    Full Text Available The aim of this study is to review a procarcinogen, the N-Nitrosodimethylamine (NDMA, liver and kidney functional enzymes (in assessing action of toxicants such as NDMA as well as oxidative stress parameters (in assessing the extent of free radical damage and scavenging. Catalase and hydro peroxidase enzymes convert hydrogen peroxide and hydro peroxides to non-radical forms and functions as natural antioxidant in human body. Enzymes like Superoxide Dismutase (SOD and Catalase (CAT and compounds such as tocopherol and ascorbic acid can protect organisms against free radical damage. Lipid peroxidation is a mechanism generally recognized as being the most important in the pathogenesis of liver injury by a number of toxic compounds including NDMA.

  7. Thymosin beta 4 protects cardiomyocytes from oxidative stress by targeting anti-oxidative enzymes and anti-apoptotic genes.

    Directory of Open Access Journals (Sweden)

    Chuanyu Wei

    Full Text Available BACKGROUND: Thymosin beta-4 (Tβ4 is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. The mechanism by which Tβ4 modulates cardiac protection under oxidative stress is not known. The purpose of this study is to dissect the cardioprotective mechanism of Tβ4 on H(2O(2 induced cardiac damage. METHODS: Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were exposed to H(2O(2 and expression of antioxidant, apoptotic, and anti-inflammatory genes was evaluated by quantitative real-time PCR and western blotting. ROS levels were estimated by DCF-DA using fluorescent microscopy and fluorimetry. Selected antioxidant, anti-inflammatory and antiapoptotic genes were silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 on H(2O(2-induced cardiac damage was evaluated. RESULTS: Pre-treatment of Tβ4 resulted in reduction of the intracellular ROS levels induced by H(2O(2 in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl(2 ratio in the cardiomyocytes. Pretreatment with Tβ4 resulted in stimulating the expression of antioxidant enzymes copper/zinc SOD and catalase in cardiomyocytes at both transcription and translation levels. Tβ4 treatment resulted in the increased expression of anti-apoptotic and anti-inflammatory genes. Silencing of Cu/Zn SOD and catalase gene resulted in apoptotic cell death in the cardiomyocytes which was prevented by treatment with Tβ4. CONCLUSION: This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes and its capability to selectively upregulate anti-oxidative enzymes, anti-inflammatory genes, and antiapoptotic enzymes in the neonatal cardiomyocytes thus preventing cell death thereby protecting the myocardium. Tβ4 treatment resulted in decreased oxidative stress and inflammation in the

  8. Immunological detection of enzymes for sulfate reduction in anaerobic methane-oxidizing consortia.

    Science.gov (United States)

    Milucka, Jana; Widdel, Friedrich; Shima, Seigo

    2013-05-01

    Anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) at marine gas seeps is performed by archaeal-bacterial consortia that have so far not been cultivated in axenic binary or pure cultures. Knowledge about possible biochemical reactions in AOM consortia is based on metagenomic retrieval of genes related to those in archaeal methanogenesis and bacterial sulfate reduction, and identification of a few catabolic enzymes in protein extracts. Whereas the possible enzyme for methane activation (a variant of methyl-coenzyme M reductase, Mcr) was shown to be harboured by the archaea, enzymes for sulfate activation and reduction have not been localized so far. We adopted a novel approach of fluorescent immunolabelling on semi-thin (0.3-0.5 μm) cryosections to localize two enzymes of the SR pathway, adenylyl : sulfate transferase (Sat; ATP sulfurylase) and dissimilatory sulfite reductase (Dsr) in microbial consortia from Black Sea methane seeps. Both Sat and Dsr were exclusively found in an abundant microbial morphotype (c. 50% of all cells), which was tentatively identified as Desulfosarcina/Desulfococcus-related bacteria. These results show that ANME-2 archaea in the Black Sea AOM consortia did not express bacterial enzymes of the canonical sulfate reduction pathway and thus, in contrast to previous suggestions, most likely cannot perform canonical sulfate reduction. Moreover, our results show that fluorescent immunolabelling on semi-thin cryosections which to our knowledge has been so far only applied on cell tissues, is a powerful tool for intracellular protein detection in natural microbial associations.

  9. Purification and characterization of laccase from Coriolopsis floccosa MTCC-1177 and its use in the selective oxidation of aromatic methyl group to aldehyde without mediators

    Indian Academy of Sciences (India)

    P K Chaurasia; A Yadav; R S S Yadav; S Yadava

    2013-11-01

    A laccase from the culture filtrate of white rot fungus Coriolopsis floccosa MTCC-1177 has been purified to homogeneity. The method involved concentration of the culture filtrate by ammonium sulphate precipitation and an anion exchange chromatography on diethylaminoethyl (DEAE) cellulose. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) as well as native polyacrylamide gel electrophoresis (native-PAGE) produced single protein bands indicating that the enzyme preparation was pure. Molecular mass of the enzyme determined from SDS-PAGE analysis was 64 kDa. Using 2,6-dimethoxyphenol (DMP), 2,2'-[Azino-bis-(3-ethylbonzthiazoline-6-sulphonic acid (ABTS) diammonium salt and 4-hydroxy-3,5-dimethoxy benzaldehyde azine (syringaldazine) as the substrates, the m, cat and cat/m values of the laccase were found to be 112.5 M, 5.16 s-1, 4.60 × 104M-1 s-1, 58 M, 5.16 s-1, 8.90 × 104M-1 s-1 and 100 M, 5.16 s-1, 5.16 × 104M-1 s-1, respectively. The pH and temperature optima were 5.0°C and 40°C, respectively. Activation energy for thermal denaturation of the enzyme was 36.6 kJ/mol/K. The enzyme was most stable at pH4.0 when exposed for 1 h. The purified laccase has yellow colour and does not show absorption band around 610 nm found in blue laccases. The enzyme transforms toluene, 3-nitrotoluene and 4-chlorotoluene to benzaldehyde, 3-nitrobenzaldehyde and 4-chlorobenzaldehyde, respectively, in the absence of electron transfer mediators.

  10. Indirect evaluation of corneal apoptosis in contact lens wearers by estimation of nitric oxide and antioxidant enzymes in tears

    Directory of Open Access Journals (Sweden)

    R P Bhatia

    2010-01-01

    Full Text Available Background : Contact lens induced trauma to the corneal epithelium results in increased release of inflammatory mediators. The keratocyte apoptosis is directly related to epithelial injury and has been correlated with increased production of nitric oxide. Potent antioxidant enzymes protect cells from oxidative damage by inactivating reactive oxygen species and thus inhibiting apoptosis. This study aims at determination of total nitric oxide and antioxidant enzymes in tears which will be an indirect criteria for assessing apoptosis. Materials and Methods : Nitric oxide and antioxidant enzymes were estimated in tears of 25 soft contact lens wearers and compared with 25 age and sex matched controls. Results : Statistically significant increase of nitric oxide (P< 0.001, superoxide dismutase (P< 0.001 and glutathione peroxidase (P< 0.001 levels was seen in tears of contact lens wearers as compared to controls. There was also statistically significant increase in the levels of antioxidant enzymes, superoxide dismutase (P< 0.05 and glutathione peroxidase (P< 0.01, with increase in the total duration of contact lens wear in years. Conclusions : Increase in the level of nitric oxide and antioxidant enzymes in tears of contact lens wearers suggested that contact lens wear suppresses the process of apoptosis. However, it was also postulated that the increased levels of nitric oxide balances the anti-apoptotic activities of increased levels of antioxidant enzymes by its pro-apoptotic activity leading to protective outcomes in contact lens wearers.

  11. Alcohol, Aldehydes, Adducts and Airways.

    Science.gov (United States)

    Sapkota, Muna; Wyatt, Todd A

    2015-11-05

    Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.

  12. Trifluorosubstrates as mechanistic probes for an FMN-dependent l-2-hydroxy acid-oxidizing enzyme.

    Science.gov (United States)

    Lederer, Florence; Vignaud, Caroline; North, Paul; Bodevin, Sabrina

    2016-09-01

    A controversy exists with respect to the mechanism of l-2-hydroxy acid oxidation by members of a family of FMN-dependent enzymes. A so-called carbanion mechanism was initially proposed, in which the active site histidine abstracts the substrate α-hydrogen as a proton, followed by electron transfer from the carbanion to the flavin. But an alternative mechanism was not incompatible with some results, a mechanism in which the active site histidine instead picks up the substrate hydroxyl proton and a hydride transfer occurs. Even though more recent experiments ruling out such a mechanism were published (Rao & Lederer (1999) Protein Science 7, 1531-1537), a few authors have subsequently interpreted their results with variant enzymes in terms of a hydride transfer. In the present work, we analyse the reactivity of trifluorolactate, a substrate analogue, with the flavocytochrome b2 (Fcb2) flavodehydrogenase domain, compared to its reactivity with an NAD-dependent lactate dehydrogenase (LDH), for which this compound is known to be an inhibitor (Pogolotti & Rupley (1973) Biochem. Biophys. Res. Commun, 55, 1214-1219). Indeed, electron attraction by the three fluorine atoms should make difficult the removal of the α-H as a hydride. We also analyse the reactivity of trifluoropyruvate with the FMN- and NAD-dependent enzymes. The results substantiate a different effect of the fluorine substituents on the two enzymes compared to their normal substrates. In the discussion we analyse the conclusions of recent papers advocating a hydride transfer mechanism for the family of l-2-hydroxy acid oxidizing FMN-dependent enzymes. PMID:27155230

  13. Women have higher protein content of beta-oxidation enzymes in skeletal muscle than men.

    Directory of Open Access Journals (Sweden)

    Amy C Maher

    Full Text Available It is well recognized that compared with men, women have better ultra-endurance capacity, oxidize more fat during endurance exercise, and are more resistant to fat oxidation defects i.e. diet-induced insulin resistance. Several groups have shown that the mRNA and protein transcribed and translated from genes related to transport of fatty acids into the muscle are greater in women than men; however, the mechanism(s for the observed sex differences in fat oxidation remains to be determined. Muscle biopsies from the vastus lateralis were obtained from moderately active men (N=12 and women (N=11 at rest to examine mRNA and protein content of genes involved in lipid oxidation. Our results show that women have significantly higher protein content for tri-functional protein alpha (TFPalpha, very long chain acyl-CoA dehydrogenase (VLCAD, and medium chain acyl-CoA dehydrogenase (MCAD (P<0.05. There was no significant sex difference in the expression of short-chain hydroxyacyl-CoA dehydrogenase (SCHAD, or peroxisome proliferator activated receptor alpha (PPARalpha, or PPARgamma, genes potentially involved in the transcriptional regulation of lipid metabolism. In conclusion, women have more protein content of the major enzymes involved in long and medium chain fatty acid oxidation which could account for the observed differences in fat oxidation during exercise.

  14. Detoxification potential and expression analysis of eutypine reducing aldehyde reductase (VrALR) during progressive drought and recovery in Vigna radiata (L.) Wilczek roots.

    Science.gov (United States)

    Sengupta, Debashree; Mudalkar, Shalini; Reddy, Attipalli R

    2012-10-01

    Generation of reactive oxygen species (ROS) in plants is an inevitable consequence of adverse environmental cues and the ability to detoxify deleterious by-products of ROS-mediated oxidation reactions reflect an important defence strategy to combat abiotic stress. Here, we have cloned the eutypine reducing aldehyde reductase gene (VrALR) from Vigna radiata (L.) Wilczek roots. We have expressed and purified the VrALR protein and analyzed its enzyme kinetic parameters and catalytic efficiency with three different substrates to confirm its identity. The functional characterization of this enzyme was unravelled through heterologous expression of the gene in Escherichia coli BL21 and an oxidative stress-sensitive Saccharomyces cerevisiae mutant strain, W3O3-1-A. Finally, the endogenous VrALR enzyme activity and the mRNA expression patterns of the VrALR gene in the roots of V. radiata in response to progressive drought stress in vivo was studied to correlate the ROS-detoxifying role of this important enzyme under the influence of progressive drought stress. Our results, for the first time, demonstrate that eutypine reducing VrALR provides varying degree of stress tolerance in bacteria, yeast systems and also plays a promising protective role against oxidative stress in V. radiata roots during gradual water deprivation. The present study provides an unequivocal evidence to understand the crucial role of aldehyde reductase ROS-detoxifying system which is highly essential for developing stress tolerance in economically important crop plants. PMID:22837052

  15. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry

    OpenAIRE

    Muhlisin,; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-01-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw...

  16. Fast and Green Microwave-Assisted Conversion of Essential Oil Allylbenzenes into the Corresponding Aldehydes via Alkene Isomerization and Subsequent Potassium Permanganate Promoted Oxidative Alkene Group Cleavage

    DEFF Research Database (Denmark)

    Luu, Thi Xuan Thi; Lam, Trinh To; Le, Thach Ngoc;

    2009-01-01

    oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO4 center dot 5H(2)O. The assistance by microwave irradiation results in very short reaction times (vanillin (4-hydroxy-3-methoxybenzaldehyde) has been carried...... out in a similar way, requiring however two additional microwave-assisted synthetic steps for acetylation of the hydroxy group prior to the oxidation reaction, and for the final deacetylation of vanillin acetate (4-acetoxy-3-methoxybenzaldehyde) by KF/Al2O3 under solvent-free conditions, respectively....

  17. Oxidative stress and the antioxidant enzyme system in the developing brain

    Directory of Open Access Journals (Sweden)

    So-Yeon Shim

    2013-03-01

    Full Text Available Preterm infants are vulnerable to the oxidative stress due to the production of large amounts of free radicals, antioxidant system insufficiency, and immature oligodendroglial cells. Reactive oxygen species (ROS play a pivotal role in the development of periventricular leukomalacia. The three most common ROS are superoxide (O2&#8226;-, hydroxyl radical (OH&#8226;, and hydrogen peroxide (H2O2. Under normal physiological conditions, a balance is maintained between the production of ROS and the capacity of the antioxidant enzyme system. However, if this balance breaks down, ROS can exert toxic effects. Superoxide dismutase, glutathione peroxidase, and catalase are considered the classical antioxidant enzymes. A recently discovered antioxidant enzyme family, peroxiredoxin (Prdx, is also an important scavenger of free radicals. Prdx1 expression is induced at birth, whereas Prdx2 is constitutively expressed, and Prdx6 expression is consistent with the classical antioxidant enzymes. Several antioxidant substances have been studied as potential therapeutic agents; however, further preclinical and clinical studies are required before allowing clinical application.

  18. Evaluation of gender-related differences in various oxidative stress enzymes in mice.

    Science.gov (United States)

    Chen, Ying; Ji, Li-Li; Liu, Tian-Yu; Wang, Zheng-Tao

    2011-12-31

    Oxidative stress caused by redundant free radical, lipid oxygen and peroxide usually results in the pathogenesis of various diseases, which can be alleviated by cellular antioxidant enzymes. According to statistics, there are different incidence rates of some diseases depending on the gender. The present study aimed to investigate potential gender-related differences of antioxidant enzymes in mice. The activities of glutamate-cysteine ligase (GCL), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) in the kidney, brain, lung and heart of both male and female mice were determined. Our results showed that GPx and GCL activities were higher in female kidney and brain than those in male. On the other hand, the activities of SOD were higher in female brain and lung than those in male. Moreover, female kidney appeared to show higher activities of CAT than the male kidney. But the activities of GCL and GPx were higher in male heart than those in female. Taken together, our results demonstrate that there are gender-related differences in the activities of cellular antioxidant enzymes in various important organs in mice. Variations in such enzymes may be the explanation for some gender-related diseases.

  19. Degradation of 4-aminophenol by hydrogen peroxide oxidation using enzyme from Serratia marcescens as catalyst

    Institute of Scientific and Technical Information of China (English)

    SUN Min; YAO Risheng; YOU Yahua; DENG Shengsong; GAO Wenxia

    2007-01-01

    This paper reports on the degradation of 4-aminophenol using hydrogen peroxide as oxidizer and the enzyme from Serratia marcescens AB 90027 as catalyst.The effecting factors during degradation and the degrading mechanism were studied.Also,the location of the enzyme in the cell,which could catalyze the degradation of 4-aminophenol,was analyzed.The results showed that to degrade 50 mL of 4-aminophenol whose concentration was 500 mg/L,the optimal conditions were:volume of H2O2=3 mL,temperature=40-60℃ and pH=9-10]In the degradation process,4-aminophenol was first converted to benzo quinone and NH3,then organic acids including maleic acid,fumaleic acid,and oxalic acid were formed,and then finally CO2 and H2O were generated as final products.The enzyme that could catalyze the degradation of 4-aminophenol was mainly extracellular enzyme.

  20. Effects of Microgravity On Oxidative and Antioxidant Enzymes In Mouse Hindlimb Muscle

    Science.gov (United States)

    Girten, B.; Hoopes, R.; Steele, M.; Morony, S.; Bateman, T. A.; Sun, S. (Technical Monitor)

    2002-01-01

    Gastrocnemius muscle of mice were analyzed in order to examine the effects of 12 days of microgravity on the oxidative enzyme climate synthase (CS) and the antioxidant enzyme superoxide dismutase (SOD). The female C57BL/6J mice utilized for this study were part of the Commercial Biomedical Testing Module (CBTM) payload that flew aboard STS-108. Mice were housed in Animal Enclosure Modules (AEMs) provided by NASA Ames. The flight (FLT) group and the ground control (CON) group each had 12 mice per group. The AEMs that held the CON group operated on a 48-hour delay from the FLT group and were located inside the Orbital Environmental Simulator (OES) at Kennedy Space Center. The temperature, CO2 and relative humidity inside the OES was regulated based on downlinked information from the shuttle middeck. Student T tests were used to compare groups and a p CON group while the SOD levels were significantly higher. The CS FLT mean was 19% lower and the SOD FLT mean was 17% higher than the respective CON group means. Although these findings are among the first muscle enzyme values reported for mice from a shuttle mission, these results are similar to some results previously reported for rats exposed to microgravity or hindlimb suspension. The changes seen during the CBTM payload are reflective of the deconditioning that takes place with disuse of the hindlimbs and indicate that muscle enzyme changes induced by disuse deconditioning are similar in both rodent species.

  1. Covalent Immobilization of Bacillus licheniformis γ-Glutamyl Transpeptidase on Aldehyde-Functionalized Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Meng-Chun Chi

    2013-02-01

    Full Text Available This work presents the synthesis and use of surface-modified iron oxide nanoparticles for the covalent immobilization of Bacillus licheniformis γ-glutamyl transpeptidase (BlGGT. Magnetic nanoparticles were prepared by an alkaline solution of divalent and trivalent iron ions, and they were subsequently treated with 3-aminopropyltriethoxysilane (APES to obtain the aminosilane-coated nanoparticles. The functional group on the particle surface and the amino group of BlGGT was then cross-linked using glutaraldehyde as the coupling reagent. The loading capacity of the prepared nanoparticles for BlGGT was 34.2 mg/g support, corresponding to 52.4% recovery of the initial activity. Monographs of transmission electron microscopy revealed that the synthesized nanoparticles had a mean diameter of 15.1 ± 3.7 nm, and the covalent cross-linking of the enzyme did not significantly change their particle size. Fourier transform infrared spectroscopy confirmed the immobilization of BlGGT on the magnetic nanoparticles. The chemical and kinetic behaviors of immobilized BlGGT are mostly consistent with those of the free enzyme. The immobilized enzyme could be recycled ten times with 36.2% retention of the initial activity and had a comparable stability respective to free enzyme during the storage period of 30 days. Collectively, the straightforward synthesis of aldehyde-functionalized nanoparticles and the efficiency of enzyme immobilization offer wide perspectives for the practical use of surface-bound BlGGT.

  2. Optimization of the Expression of Human Aldehyde Oxidase for Investigations of Single-Nucleotide Polymorphisms.

    Science.gov (United States)

    Foti, Alessandro; Hartmann, Tobias; Coelho, Catarina; Santos-Silva, Teresa; Romão, Maria João; Leimkühler, Silke

    2016-08-01

    Aldehyde oxidase (AOX1) is an enzyme with broad substrate specificity, catalyzing the oxidation of a wide range of endogenous and exogenous aldehydes as well as N-heterocyclic aromatic compounds. In humans, the enzyme's role in phase I drug metabolism has been established and its importance is now emerging. However, the true physiologic function of AOX1 in mammals is still unknown. Further, numerous single-nucleotide polymorphisms (SNPs) have been identified in human AOX1. SNPs are a major source of interindividual variability in the human population, and SNP-based amino acid exchanges in AOX1 reportedly modulate the catalytic function of the enzyme in either a positive or negative fashion. For the reliable analysis of the effect of amino acid exchanges in human proteins, the existence of reproducible expression systems for the production of active protein in ample amounts for kinetic, spectroscopic, and crystallographic studies is required. In our study we report an optimized expression system for hAOX1 in Escherichia coli using a codon-optimized construct. The codon-optimization resulted in an up to 15-fold increase of protein production and a simplified purification procedure. The optimized expression system was used to study three SNPs that result in amino acid changes C44W, G1269R, and S1271L. In addition, the crystal structure of the S1271L SNP was solved. We demonstrate that the recombinant enzyme can be used for future studies to exploit the role of AOX in drug metabolism, and for the identification and synthesis of new drugs targeting AOX when combined with crystallographic and modeling studies. PMID:26842593

  3. Fast and Green Microwave-Assisted Conversion of Essential Oil Allylbenzenes into the Corresponding Aldehydes via Alkene Isomerization and Subsequent Potassium Permanganate Promoted Oxidative Alkene Group Cleavage

    Directory of Open Access Journals (Sweden)

    Thi X. Thi Luu

    2009-09-01

    Full Text Available Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step “green” reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding 1-arylpropene and a subsequent solventless oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO4·5H2O. The assistance by microwave irradiation results in very short reaction times (<15 minutes. The green conversion of eugenol (4-allyl-2-methoxyphenol into vanillin (4-hydroxy-3-methoxybenzaldehyde has been carried out in a similar way, requiring however two additional microwave-assisted synthetic steps for acetylation of the hydroxy group prior to the oxidation reaction, and for the final deacetylation of vanillin acetate (4-acetoxy-3-methoxybenzaldehyde by KF/Al2O3 under solvent-free conditions, respectively.

  4. PPRODUCTION OF AROMATIC ALDEHYDE BY MICROWAVE CATALYTIC OXIDATION OF A LIGNIN MODEL COMPOUND WITH La-CONTAINING SBA-15/H2O2 SYSTEMS

    Directory of Open Access Journals (Sweden)

    Xiaoli Gu

    2010-07-01

    Full Text Available A convenient and efficient application of heterogeneous La-containing SBA-15 systems for the microwave assisted oxidation of a lignin model phenolic monomer, 4-hydroxy-1-phenylpropane, is reported. Low-cost and environmentally friendly H2O2 was used as the oxygen atom donor. The catalyst was prepared by immobilizing lanthanum species on the periodic mesoporous channels of siliceous SBA-15. Powder X-ray diffraction data and ICP-AES revealed that the host retains its hexagonal mesoporous structure after immobilization and most of the lanthanum species are better dispersed in the calcined materials. The surface area and pore size of La/SBA-15 was considerably decreased, indicating the intrapore confinement of the Lanthanum species. The activity of the La/SBA-15 was investigated in the oxidation of 4-hydroxy-1-phenylpropane in the presence of hydrogen peroxide as oxidant. 70.5% conversion of 4-hydroxy-1-phenylpropane was obtained after 30 min of reaction under 200W microwave irradiation, compared to a poor 28.1% degradation after 24h under conventional heating. The possibility of recycling the catalyst was studied.

  5. Isotopomeric characterization of nitrous oxide produced by reaction of enzymes extracted from nitrifying and denitrifying bacteria

    Directory of Open Access Journals (Sweden)

    T. Yamazaki

    2013-10-01

    Full Text Available Nitrous oxide (N2O is a potent greenhouse gas and produced in denitrification and nitrification in environmental nitrogen cycle by various microorganism. Site preference (SP of 15N in N2O, which is defined as the difference in the natural abundance of isotopomers 14N15NO and 15N14NO relative to 14N14NO, has been reported to be a useful tool to quantitatively distinguish N2O production pathway. To determine representative SP value for each microbial process, we firstly measured SP of N2O produced in the enzyme reaction of hydroxylamine oxidoreductase (HAO purified from two species of ammonia oxidizing bacteria (AOB, Nitrosomonas europaea and Nitrosococcus oceani, and that of nitric oxide reductase (NOR from Paracoccus denitrificans, respectively. The SP value for NOR reaction (−5.9 ± 2.1‰ showed nearly the same value as that reported for N2O produced by P. denitrificans in pure culture. In contrast, SP value for HAO reaction (36.3 ± 2.3‰ was a little higher than the values reported for N2O produced by AOB in aerobic pure culture. Using the SP values obtained by HAO and NOR reactions, we calculated relative contribution of the nitrite (NO2– reduction (which is followed by NO reduction to N2O production by N. oceani incubated under different O2 availability. Our calculations revealed that previous in vivo studies might have underestimated the SP value for NH2OH oxidation pathway possibly due to a small contribution of NO2– reduction pathway. Further evaluation of isotopomer signatures of N2O using common enzymes of other processes related to N2O would improve the isotopomer analysis of N2O in various environments.

  6. Isotopomeric characterization of nitrous oxide produced by reaction of enzymes extracted from nitrifying and denitrifying bacteria

    Science.gov (United States)

    Yamazaki, T.; Hozuki, T.; Arai, K.; Toyoda, S.; Koba, K.; Fujiwara, T.; Yoshida, N.

    2014-05-01

    Nitrous oxide (N2O) is a potent greenhouse gas and produced in denitrification and nitrification by various microorganisms. Site preference (SP) of 15N in N2O, which is defined as the difference in the natural abundance of isotopomers 14N15NO and 15N14NO relative to 14N14NO, has been reported to be a useful tool to quantitatively distinguish N2O production pathways. To determine representative SP values for each microbial process, we firstly measured SP of N2O produced in the enzyme reaction of hydroxylamine oxidoreductase (HAO) purified from two species of ammonia oxidizing bacteria (AOB), Nitrosomonas europaea and Nitrosococcus oceani, and that of nitric oxide reductase (NOR) from Paracoccus denitrificans. The SP value for NOR reaction (-5.9 ± 2.1‰) showed nearly the same value as that reported for N2O produced by P. denitrificans in pure culture. In contrast, SP value for HAO reaction (36.3 ± 2.3‰) was a little higher than the values reported for N2O produced by AOB in aerobic pure culture. Using the SP values obtained by HAO and NOR reactions, we calculated relative contribution of the nitrite (NO2-) reduction (which is followed by NO reduction) to N2O production by N. oceani incubated under different O2 availability. Our calculations revealed that previous in vivo studies might have underestimated the SP value for the NH2OH oxidation pathway possibly due to a small contribution of NO2- reduction pathway. Further evaluation of isotopomer signatures of N2O using common enzymes of other processes related to N2O would improve the isotopomer analysis of N2O in various environments.

  7. Enhanced Phospholipase A2 Group 3 Expression by Oxidative Stress Decreases the Insulin-Degrading Enzyme.

    Science.gov (United States)

    Yui, Daishi; Nishida, Yoichiro; Nishina, Tomoko; Mogushi, Kaoru; Tajiri, Mio; Ishibashi, Satoru; Ajioka, Itsuki; Ishikawa, Kinya; Mizusawa, Hidehiro; Murayama, Shigeo; Yokota, Takanori

    2015-01-01

    Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD) model mice showed decreased insulin-degrading enzyme (IDE) levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa-/-) mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa-/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3); Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa-/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD.

  8. Enhanced Phospholipase A2 Group 3 Expression by Oxidative Stress Decreases the Insulin-Degrading Enzyme.

    Directory of Open Access Journals (Sweden)

    Daishi Yui

    Full Text Available Oxidative stress has a ubiquitous role in neurodegenerative diseases and oxidative damage in specific regions of the brain is associated with selective neurodegeneration. We previously reported that Alzheimer disease (AD model mice showed decreased insulin-degrading enzyme (IDE levels in the cerebrum and accelerated phenotypic features of AD when crossbred with alpha-tocopherol transfer protein knockout (Ttpa-/- mice. To further investigate the role of chronic oxidative stress in AD pathophysiology, we performed DNA microarray analysis using young and aged wild-type mice and aged Ttpa-/- mice. Among the genes whose expression changed dramatically was Phospholipase A2 group 3 (Pla2g3; Pla2g3 was identified because of its expression profile of cerebral specific up-regulation by chronic oxidative stress in silico and in aged Ttpa-/- mice. Immunohistochemical studies also demonstrated that human astrocytic Pla2g3 expression was significantly increased in human AD brains compared with control brains. Moreover, transfection of HEK293 cells with human Pla2g3 decreased endogenous IDE expression in a dose-dependent manner. Our findings show a key role of Pla2g3 on the reduction of IDE, and suggest that cerebrum specific increase of Pla2g3 is involved in the initiation and/or progression of AD.

  9. Fast and Green Microwave-Assisted Conversion of Essential Oil Allylbenzenes into the Corresponding Aldehydes via Alkene Isomerization and Subsequent Potassium Permanganate Promoted Oxidative Alkene Group Cleavage

    OpenAIRE

    Thi X. Thi Luu; Trinh To Lam; Thach Ngoc Le; Fritz Duus

    2009-01-01

    Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step “green” reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding 1-arylpropene and a subsequent solventless oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO4·5H2O. The assistance by microwave irradiation results in very short reaction times (<15 minutes). The green conversion of ...

  10. Response of oxidative stress and isoflavone treatment on superoxide dismutase enzyme activities and lipid peroxidation in rat’s liver

    OpenAIRE

    Suarsana IN; Wresdiyati T; Suprayogi A

    2013-01-01

    Oxidative stress is defined as over-production of free radicals which lead to cells damage, pathological condition and cell death. The objective of this study was to analyze respond of oxidative stress and isoflavone treatment on superoxide dismutase (SOD) enzyme activities and lipid peroxidation in rat liver. A total of fifteen male Spraque Dawley rats were used in this study. They were sub-divided into three groups; (1) a negative control group, (2) a stress oxidative group, and (3) treatme...

  11. Expression profile of oxidative and antioxidative stress enzymes based on ESTs approach of citrus

    Directory of Open Access Journals (Sweden)

    Luis Antonio Peroni

    2007-01-01

    Full Text Available Plants not only evolve but also reduce oxygen in photosynthesis. An inevitable consequence of this normal process is the production of reactive oxygen species (ROS. Plants are adequately protected by the presence of multiple antioxidative enzymes in the cytosol and also in the different cell organelles such as chloroplasts, mitochondria, and peroxisomes. Traditionally, ROS were considered to be only a toxic byproduct of aerobic metabolism. However, recently it has become apparent that plants actively produce these molecules which may control many different physiological processes such as abiotic and biotic stress response, pathogen defense and systemic signaling. The search results using the Citrus Genome Program in Brazil (CitEST for oxidative stress and the antioxidant enzyme system in Citrus Sinensis variety ‘Pera IAC’ indicated that the multiple ROS-scavenging enzymes were expressed throughout all citrus tissues. The analyses demonstrated the ubiquitous expression of metallothioneins, probably indicating a constitutive expression pattern. Oxalate oxidase has been identified as the most abundant expressed gene in developing fruits, which suggests a specific function in the ripening of citrus fruit. Moreover, infected leaves with Xylella fastidiosa and Leprosis citri showed a massive change in their ROS gene expression profile which may indicate that the suppression of ROS detoxifying mechanisms may be involved in the induction of the diseases.

  12. Carbon-Carbon Bond Formation and Hydrogen Production in the Ketonization of Aldehydes.

    Science.gov (United States)

    Orozco, Lina M; Renz, Michael; Corma, Avelino

    2016-09-01

    Aldehydes possess relatively high chemical energy, which is the driving force for disproportionation reactions such as Cannizzaro and Tishchenko reactions. Generally, this energy is wasted if aldehydes are transformed into carboxylic acids with a sacrificial oxidant. Here, we describe a cascade reaction in which the surplus energy of the transformation is liberated as molecular hydrogen for the oxidation of heptanal to heptanoic acid by water, and the carboxylic acid is transformed into potentially industrially relevant symmetrical ketones by ketonic decarboxylation. The cascade reaction is catalyzed by monoclinic zirconium oxide (m-ZrO2 ). The reaction mechanism has been studied through cross-coupling experiments between different aldehydes and acids, and the final symmetrical ketones are formed by a reaction pathway that involves the previously formed carboxylic acids. Isotopic studies indicate that the carboxylic acid can be formed by a hydride shift from the adsorbed aldehyde on the metal oxide surface in the absence of noble metals. PMID:27539722

  13. Oxidative stress related enzymes in response to chromium (Ⅵ) toxicity in Oxya chinensis ( Orthoptera : Acridoidae)

    Institute of Scientific and Technical Information of China (English)

    LI Li-jun; ZHANG Feng; LIU Xue-mei; GUO Ya-ping; MA En-bo

    2005-01-01

    The toxic effects of Cr(Ⅵ) on antioxidant enzymes of Oxya chinensis(Orthoptera: Acridoidae) were determined. Changes in the activities of the antioxidant enzymes superoxide dismutase(SOD), catalase(CAT), and guaiacol peroxidase(GPx) were measured in O. chinensis insects injected with Cr(Ⅵ). Fifth-nymphs of O. chinensis insects were injected with Cr(Ⅵ) with different concentrations (0, 75, 150, 225, 300, 375, 450 mg/kg of body weight). The results showed that Cr(Ⅵ) led to the change of SOD, CAT, and GPx activities at different concentrations, which revealed that: (1) The oxidative stress of SOD increased with the increase of Cr (Ⅵ)concentration. (2) With the increase of Cr (Ⅵ) concentrations, CAT activities for females increased at lower concentrations, but decreased at higher concentration range, which indicated that antioxidant system of O. chinensis was not influenced by the presence of Cr (Ⅵ). A very similar response to Cr(Ⅵ) effect for males indicated that Cr(Ⅵ) concentrations were not high enough to damage O. chinensis in terms of CAT. (3) The GPx activity for females increased in all treatments, which revealed that the damage power of Cr(Ⅵ)was increased with the increase of Cr(Ⅵ) concentrations in terms of GPx, but the effect was not so remarkable. There was not a consistent trend of GPx activities for males in all treatments of Cr(Ⅵ). Cr(Ⅵ)-induced changes in antioxidant enzymes were different for SOD, CAT and GPx, of which the tendency was that activities generally changed with increase of concentrations of Cr(Ⅵ) suggesting SOD, CAT, and GPx could serve as indices of oxidative stress to some extent.

  14. Nitric oxide mitigates salt stress by regulating levels of osmolytes and antioxidant enzymes in chickpea

    Directory of Open Access Journals (Sweden)

    Parvaiz eAhmad

    2016-03-01

    Full Text Available This work was designed to evaluate whether external application of nitric oxide (NO in the form of its donor S-nitroso-N-acetylpenicillamine (SNAP could mitigate the deleterious effects of NaCl stress on chickpea (Cicer arietinum L. plants. SNAP (50 μM was applied to chickpea plants grown under non-saline and saline conditions (50 and 100 mM NaCl. Salt stress negatively affected growth and biomass yield, leaf relative water content (LRWC and chlorophyll content of chickpea plants. High salinity increased electrolyte leakage, carotenoid content and the levels of osmolytes (proline, glycine betaine, soluble proteins and soluble sugars, hydrogen peroxide (H2O2 and malondialdehyde (MDA, as well as the activities of antioxidant enzymes, such as superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase (APX, and glutathione reductase (GR in chickpea plants. Expression of the representative SOD, CAT and APX genes examined was also up-regulated in chickpea plants by salt stress. On the other hand, exogenous application of NO to salinized plants enhanced the growth parameters, LRWC, photosynthetic pigment production and levels of osmolytes, as well as the activities of examined antioxidant enzymes which is correlated with up-regulation of the examined SOD, CAT and APX genes, in comparison with plants treated with NaCl only. Furthermore, electrolyte leakage, H2O2 and MDA contents showed decline in salt-stressed plants supplemented with NO as compared with those in NaCl-treated plants alone. Thus, the exogenous application of NO protected chickpea plants against salt-induced oxidative damage by enhancing the biosynthesis of antioxidant enzymes, thereby improving plant growth under saline stress. Taken together, our results demonstrate that NO has capability to mitigate the adverse effects of high salinity on chickpea plants by improving LRWC, photosynthetic pigment biosyntheses, osmolyte accumulation and antioxidative defense system.

  15. Novel insights into the fungal oxidation of monoaromatic and biarylic environmental pollutants by characterization of two new ring cleavage enzymes.

    Science.gov (United States)

    Schlüter, Rabea; Lippmann, Ramona; Hammer, Elke; Gesell Salazar, Manuela; Schauer, Frieder

    2013-06-01

    The phenol-degrading yeast Trichosporon mucoides can oxidize and detoxify biarylic environmental pollutants such as dibenzofuran, diphenyl ether and biphenyl by ring cleavage. The degradation pathways are well investigated, but the enzymes involved are not. The high similarity of hydroxylated biphenyl derivatives and phenol raised the question if the enzymes of the phenol degradation are involved in ring cleavage or whether specific enzymes are necessary. Purification of enzymes from T. mucoides with catechol cleavage activity demonstrated the existence of three different enzymes: a classical catechol-1,2-dioxygenase (CDO), not able to cleave the aromatic ring system of 3,4-dihydroxybiphenyl, and two novel enzymes with a high affinity towards 3,4-dihydroxybiphenyl. The comparison of the biochemical characteristics and mass spectrometric sequence data of these three enzymes demonstrated that they have different substrate specificities. CDO catalyzes the ortho-cleavage of dihydroxylated monoaromatic compounds, while the two novel enzymes carry out a similar reaction on biphenyl derivatives. The ring fission of 3,4-dihydroxybiphenyl by the purified enzymes results in the formation of (5-oxo-3-phenyl-2,5-dihydrofuran-2-yl)acetic acid. These results suggest that the ring cleavage enzymes catalyzing phenol degradation are not involved in the ring cleavage of biarylic compounds by this yeast, although some intermediates of the phenol metabolism may function as inducers.

  16. Response of oxidative enzyme activities to nitrogen deposition affects soil concentrations of dissolved organic carbon

    Science.gov (United States)

    Waldrop, M.P.; Zak, D.R.

    2006-01-01

    Recent evidence suggests that atmospheric nitrate (NO3- ) deposition can alter soil carbon (C) storage by directly affecting the activity of lignin-degrading soil fungi. In a laboratory experiment, we studied the direct influence of increasing soil NO 3- concentration on microbial C cycling in three different ecosystems: black oak-white oak (BOWO), sugar maple-red oak (SMRO), and sugar maple-basswood (SMBW). These ecosystems span a broad range of litter biochemistry and recalcitrance; the BOWO ecosystem contains the highest litter lignin content, SMRO had intermediate lignin content, and SMBW leaf litter has the lowest lignin content. We hypothesized that increasing soil solution NO 3- would reduce lignolytic activity in the BOWO ecosystem, due to a high abundance of white-rot fungi and lignin-rich leaf litter. Due to the low lignin content of litter in the SMBW, we further reasoned that the NO3- repression of lignolytic activity would be less dramatic due to a lower relative abundance of white-rot basidiomycetes; the response in the SMRO ecosystem should be intermediate. We increased soil solution NO3- concentrations in a 73-day laboratory incubation and measured microbial respiration and soil solution dissolved organic carbon (DOC) and phenolics concentrations. At the end of the incubation, we measured the activity of ??-glucosidase, N-acetyl-glucosaminidase, phenol oxidase, and peroxidase, which are extracellular enzymes involved with cellulose and lignin degradation. We quantified the fungal biomass, and we also used fungal ribosomal intergenic spacer analysis (RISA) to gain insight into fungal community composition. In the BOWO ecosystem, increasing NO 3- significantly decreased oxidative enzyme activities (-30% to -54%) and increased DOC (+32% upper limit) and phenolic (+77% upper limit) concentrations. In the SMRO ecosystem, we observed a significant decrease in phenol oxidase activity (-73% lower limit) and an increase in soluble phenolic concentrations

  17. Oxidative stress enzyme and histopathological lesions in Colossoma macropomum (pisces, ariidae) for environmental impact assessment

    Science.gov (United States)

    Andrade, Ticianne de Sousa de Oliveira Mota; Sousa, Debora Batista Pinheiro; Dantas, Janaina Gomes; Castro, Jonatas da Silva; Neta, Raimunda Nonata Fortes Carvalho

    2015-12-01

    This study used oxidative stress enzyme (Glutathione S-Transferase and Catalase), histopathological lesions (Branchial lesions) and biometric data in the freshwater fish tambaqui, Colossoma macropomum, to assess environmental impacts in an Environmental Protection Area at São Luis, Brazil. Fish were sampled from two locations (A1 = contaminated area and A2 = reference site) within the protected area on four occasions. The activity of catalase (CAT) and glutathione S-transferase (GST) in C. macropomum was compared with biometric data and histopathological lesions. Results have shown that biometric data decreased significantly in fish (p<0.05) at the contaminated site. The activity of CAT was higher in fish specifically caught in A1. A significant difference was observed in the GST activity in the liver of C. macropomum when comparing fish from the contaminated site and those from the reference site (p<0.05).

  18. Enzyme catalyzed oxidative cross-linking of feruloylated pectic polysaccharides from sugar beet

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz

    beet pulp as a potential starting material for production of pectin derived products which could help maintain the competitiveness of the sugar beet based industry. The overall objective of this study has been focusing on understanding the kinetics of enzyme catalyzed oxidative crosslinking......Sugar beet pulp is a byproduct from sugar production consisting mainly of cellulose and pectic polysaccharide. Its utilization has been mostly as feedstock due to its high content of energy and fiber. This study emphasizes on the utilization of the pectin and arabinan fractions extracted from sugar...... of feruloylated polysaccharide from sugar beet and relating the kinetics of this crosslinking to the properties of the cross-linked products. Several hypotheses have been formulated in order to accomplish our objective. The first part of the study utilized arabinan-oligosaccharide fraction from sugar beet pulp...

  19. Unravelling the Interactions between Hydrolytic and Oxidative Enzymes in Degradation of Lignocellulosic Biomass by Sporothrix carnis under Various Fermentation Conditions.

    Science.gov (United States)

    Ogunyewo, Olusola A; Olajuyigbe, Folasade M

    2016-01-01

    The mechanism underlying the action of lignocellulolytic enzymes in biodegradation of lignocellulosic biomass remains unclear; hence, it is crucial to investigate enzymatic interactions involved in the process. In this study, degradation of corn cob by Sporothrix carnis and involvement of lignocellulolytic enzymes in biodegradation were investigated over 240 h cultivation period. About 60% degradation of corn cob was achieved by S. carnis at the end of fermentation. The yields of hydrolytic enzymes, cellulase and xylanase, were higher than oxidative enzymes, laccase and peroxidase, over 144 h fermentation period. Maximum yields of cellulase (854.4 U/mg) and xylanase (789.6 U/mg) were at 96 and 144 h, respectively. Laccase and peroxidase were produced cooperatively with maximum yields of 489.06 U/mg and 585.39 U/mg at 144 h. Drastic decline in production of cellulase at 144 h (242.01 U/mg) and xylanase at 192 h (192.2 U/mg) indicates that they play initial roles in biodegradation of lignocellulosic biomass while laccase and peroxidase play later roles. Optimal degradation of corn cob (76.6%) and production of hydrolytic and oxidative enzymes were achieved with 2.5% inoculum at pH 6.0. Results suggest synergy in interactions between the hydrolytic and oxidative enzymes which can be optimized for improved biodegradation. PMID:26881077

  20. Unravelling the Interactions between Hydrolytic and Oxidative Enzymes in Degradation of Lignocellulosic Biomass by Sporothrix carnis under Various Fermentation Conditions

    Directory of Open Access Journals (Sweden)

    Olusola A. Ogunyewo

    2016-01-01

    Full Text Available The mechanism underlying the action of lignocellulolytic enzymes in biodegradation of lignocellulosic biomass remains unclear; hence, it is crucial to investigate enzymatic interactions involved in the process. In this study, degradation of corn cob by Sporothrix carnis and involvement of lignocellulolytic enzymes in biodegradation were investigated over 240 h cultivation period. About 60% degradation of corn cob was achieved by S. carnis at the end of fermentation. The yields of hydrolytic enzymes, cellulase and xylanase, were higher than oxidative enzymes, laccase and peroxidase, over 144 h fermentation period. Maximum yields of cellulase (854.4 U/mg and xylanase (789.6 U/mg were at 96 and 144 h, respectively. Laccase and peroxidase were produced cooperatively with maximum yields of 489.06 U/mg and 585.39 U/mg at 144 h. Drastic decline in production of cellulase at 144 h (242.01 U/mg and xylanase at 192 h (192.2 U/mg indicates that they play initial roles in biodegradation of lignocellulosic biomass while laccase and peroxidase play later roles. Optimal degradation of corn cob (76.6% and production of hydrolytic and oxidative enzymes were achieved with 2.5% inoculum at pH 6.0. Results suggest synergy in interactions between the hydrolytic and oxidative enzymes which can be optimized for improved biodegradation.

  1. Antioxidant enzymes activities of Burkholderia spp. strains-oxidative responses to Ni toxicity.

    Science.gov (United States)

    Dourado, M N; Franco, M R; Peters, L P; Martins, P F; Souza, L A; Piotto, F A; Azevedo, R A

    2015-12-01

    Increased agriculture production associated with intense application of herbicides, pesticides, and fungicides leads to soil contamination worldwide. Nickel (Ni), due to its high mobility in soils and groundwater, constitutes one of the greatest problems in terms of environmental pollution. Metals, including Ni, in high concentrations are toxic to cells by imposing a condition of oxidative stress due to the induction of reactive oxygen species (ROS), which damage lipids, proteins, and DNA. This study aimed to characterize the Ni antioxidant response of two tolerant Burkholderia strains (one isolated from noncontaminated soil, SNMS32, and the other from contaminated soil, SCMS54), by measuring superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione S-transferase (GST) activities. Ni accumulation and bacterial growth in the presence of the metal were also analyzed. The results showed that both strains exhibited different trends of Ni accumulation and distinct antioxidant enzymes responses. The strain from contaminated soil (SCMS54) exhibited a higher Ni biosorption and exhibited an increase in SOD and GST activities after 5 and 12 h of Ni exposure. The analysis of SOD, CAT, and GR by nondenaturing PAGE revealed the appearance of an extra isoenzyme in strain SCMS54 for each enzyme. The results suggest that the strain SCMS54 isolated from contaminated soil present more plasticity with potential to be used in soil and water bioremediation. PMID:26289332

  2. A highly sensitive electrochemical biosensor for catechol using conducting polymer reduced graphene oxide-metal oxide enzyme modified electrode.

    Science.gov (United States)

    Sethuraman, V; Muthuraja, P; Anandha Raj, J; Manisankar, P

    2016-10-15

    The fabrication, characterization and analytical performances were investigated for a catechol biosensor, based on the PEDOT-rGO-Fe2O3-PPO composite modified glassy carbon (GC) electrode. The graphene oxide (GO) doped conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) was prepared through electrochemical polymerization by potential cycling. Reduction of PEDOT-GO was carried out by amperometric method. Fe2O3 nanoparticles were synthesized in ethanol by hydrothermal method. The mixture of Fe2O3, PPO and glutaraldehyde was casted on the PEDOT-rGO electrode. The surface morphology of the modified electrodes was studied by FE-SEM and AFM. Cyclic voltammetric studies of catechol on the enzyme modified electrode revealed higher reduction peak current. Determination of catechol was carried out successfully by Differential Pulse Voltammetry (DPV) technique. The fabricated biosensor investigated shows a maximum current response at pH 6.5. The catechol biosensor exhibited wide sensing linear range from 4×10(-8) to 6.20×10(-5)M, lower detection limit of 7×10(-9)M, current maxima (Imax) of 92.55µA and Michaelis-Menten (Km) constant of 30.48µM. The activation energy (Ea) of enzyme electrode is 35.93KJmol(-1) at 50°C. There is no interference from d-glucose and l-glutamic acid, ascorbic acid and o-nitrophenol. The PEDOT-rGO-Fe2O3-PPO biosensor was stable for at least 75 days when stored in a buffer at about 4°C. PMID:26751827

  3. EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 73, Revision 1: Consideration of alicyclic primary alcohols, aldehydes, acids and related esters evaluated by JECFA (59th meeting) structurally related to primary saturated or unsaturated alicyclic alcohol, aldehyde, and esters evaluated by EFSA in FGE.12Rev2 (2011)

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... levels of intake as flavouring substances” based on the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for all 16 substances, the information is adequate....

  4. Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora) Hydrolysates

    OpenAIRE

    Raheleh Ghanbari; Mohammad Zarei; Afshin Ebrahimpour; Azizah Abdul-Hamid; Amin Ismail; Nazamid Saari

    2015-01-01

    In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates,...

  5. Respiratory burst enzymes, pro-oxidants and antioxidants status in Bangladeshi population with β-thalassemia major

    OpenAIRE

    Md. Faruk Hossain; Md. Ismail; Arifur Rahman Tanu; Hossain Uddin Shekhar

    2015-01-01

    Background: Oxidative stress is intimately associated with many diseases, including β-thalassemia. Aim: The study was to estimate the status of respiratory burst enzymes, pro-oxidants, and antioxidants in β-thalassemia major patients in Bangladesh and to compare with apparently healthy individuals. Materials and Methods: A total of 49 subjects were recruited which included 25 patients (age range 5 to 40 years) with β-thalassemia major and 24 controls (age and sex matched). Superoxide dismutas...

  6. Process requirements of galactose oxidase catalyzed oxidation of alcohols

    DEFF Research Database (Denmark)

    Pedersen, Asbjørn Toftgaard; R. Birmingham, William; Rehn, Gustav;

    2015-01-01

    biocatalyst for the oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones, respectively. However, GOase requires a number of additives to sustain its catalytic function, such as the enzyme catalase for degradation of the byproduct hydrogen peroxide as well as single......-electron oxidants to reactivate the enzyme upon loss of the amino acid radical in its active site. In this work, the addition of catalase, single-electron oxidants, and copper ions was investigated systematically in order to find the minimum concentrations required to obtain a fully active GOase. Furthermore...

  7. Glu504Lys Single Nucleotide Polymorphism of Aldehyde Dehydrogenase 2 Gene and the Risk of Human Diseases

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2015-01-01

    Full Text Available Aldehyde dehydrogenase (ALDH 2 is a mitochondrial enzyme that is known for its important role in oxidation and detoxification of ethanol metabolite acetaldehyde. ALDH2 also metabolizes other reactive aldehydes such as 4-hydroxy-2-nonenal and acrolein. The Glu504Lys single nucleotide polymorphism (SNP of ALDH2 gene, which is found in approximately 40% of the East Asian populations, causes defect in the enzyme activity of ALDH2, leading to alterations in acetaldehyde metabolism and alcohol-induced “flushing” syndrome. Evidence suggests that ALDH2 Glu504Lys SNP is a potential candidate genetic risk factor for a variety of chronic diseases such as cardiovascular disease, cancer, and late-onset Alzheimer’s disease. In addition, the association between ALDH2 Glu504Lys SNP and the development of these chronic diseases appears to be affected by the interaction between the SNP and lifestyle factors such as alcohol consumption as well as by the presence of other genetic variations.

  8. Kinetics of forming aldehydes in frying oils and their distribution in French fries revealed by LC-MS-based chemometrics

    Science.gov (United States)

    Aldehydes are major secondary lipid oxidation products (LOPs) from heating vegetable oils and deep frying. The routes and reactions that generate aldehydes have been extensively investigated, but the sequences and kinetics of their formation in oils are poorly defined. In this study, a platform comb...

  9. GRE2 from Scheffersomyces stipitis as an aldehyde reductase contributes tolerance to aldehyde inhibitors derived from lignocellulosic biomass.

    Science.gov (United States)

    Wang, Xu; Ma, Menggen; Liu, Z Lewis; Xiang, Quanju; Li, Xi; Liu, Na; Zhang, Xiaoping

    2016-08-01

    Scheffersomyces (Pichia) stipitis is one of the most promising yeasts for industrial bioethanol production from lignocellulosic biomass. S. stipitis is able to in situ detoxify aldehyde inhibitors (such as furfural and 5-hydroxymethylfurfural (HMF)) to less toxic corresponding alcohols. However, the reduction enzymes involved in this reaction remain largely unknown. In this study, we reported that an uncharacterized open reading frame PICST_72153 (putative GRE2) from S. stipitis was highly induced in response to furfural and HMF stresses. Overexpression of this gene in Saccharomyces cerevisiae improved yeast tolerance to furfural and HMF. GRE2 was identified as an aldehyde reductase which can reduce furfural to FM with either NADH or NADPH as the co-factor and reduce HMF to FDM with NADPH as the co-factor. This enzyme can also reduce multiple aldehydes to their corresponding alcohols. Amino acid sequence analysis indicated that it is a member of the subclass "intermediate" of the short-chain dehydrogenase/reductase (SDR) superfamily. Although GRE2 from S. stipitis is similar to GRE2 from S. cerevisiae in a three-dimensional structure, some differences were predicted. GRE2 from S. stipitis forms loops at D133-E137 and T143-N145 locations with two α-helices at E154-K157 and E252-A254 locations, different GRE2 from S. cerevisiae with an α-helix at D133-E137 and a β-sheet at T143-N145 locations, and two loops at E154-K157 and E252-A254 locations. This research provided guidelines for the study of other SDR enzymes from S. stipitis and other yeasts on tolerant mechanisms to aldehyde inhibitors derived from lignocellulosic biomass. PMID:27003269

  10. Endurance exercise induces mRNA expression of oxidative enzymes in human skeletal muscle late in recovery

    DEFF Research Database (Denmark)

    Leick, Lotte; Plomgaard, Peter S.; Grønløkke, L.;

    2010-01-01

    exercise. To test the hypothesis that mRNA expression of many oxidative enzymes is up-regulated late in recovery (10-24 h) after exercise, male subjects (n=8) performed a 90-min cycling exercise (70% VO(2-max)), with muscle biopsies obtained before exercise (pre), and after 10, 18 and 24 h of recovery...

  11. Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver.

    Science.gov (United States)

    Reza, Hasan Mahmud; Tabassum, Nabila; Sagor, Md Abu Taher; Chowdhury, Mohammed Riaz Hasan; Rahman, Mahbubur; Jain, Preeti; Alam, Md Ashraful

    2016-01-01

    Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats. PMID:26862777

  12. INTERACTION OF ALDEHYDES DERIVED FROM LIPID PEROXIDATION AND MEMBRANE PROTEINS.

    Directory of Open Access Journals (Sweden)

    Stefania ePizzimenti

    2013-09-01

    Full Text Available A great variety of compounds are formed during lipid peroxidation of polyunsaturated fatty acids of membrane phospholipids. Among them, bioactive aldehydes, such as 4-hydroxyalkenals, malondialdehyde (MDA and acrolein, have received particular attention since they have been considered as toxic messengers that can propagate and amplify oxidative injury. In the 4-hydroxyalkenal class, 4-hydroxy-2-nonenal (HNE is the most intensively studied aldehyde, in relation not only to its toxic function, but also to its physiological role. Indeed, HNE can be found at low concentrations in human tissues and plasma and participates in the control of biological processes, such as signal transduction, cell proliferation and differentiation. Moreover, at low doses, HNE exerts an anti-cancer effect, by inhibiting cell proliferation, angiogenesis, cell adhesion and by inducing differentiation and/or apoptosis in various tumor cell lines. It is very likely that a substantial fraction of the effects observed in cellular responses, induced by HNE and related aldehydes, be mediated by their interaction with proteins, resulting in the formation of covalent adducts or in the modulation of their expression and/or activity. In this review we focus on membrane proteins affected by lipid peroxidation-derived aldehydes, under physiological and pathological conditions.

  13. Inactivation of enzymes and oxidative modification of proteins by stimulated neutrophils.

    Science.gov (United States)

    Oliver, C N

    1987-02-15

    Differentiated, stimulated HL-60 cells and freshly isolated, stimulated neutrophils inactivate glutamine synthetase (L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2) either inside or outside of Escherichia coli. Stimulated neutrophils also inactivate at least four endogenous enzymes which are inactivated by mixed-function oxidation (MFO) systems in vitro (L. Fucci, C.N. Oliver, M.J. Coon, and E.R. Stadtman (1983) Proc. Natl. Acad. Sci. USA 80, 1521-1525). The inactivation of glutamine synthetase by stimulated neutrophils exhibits characteristics similar to those previously described using both enzymic and nonenzymic MFO systems (R.L. Levine, C.N. Oliver, R.M. Fulks, and E.R. Stadtman (1981) Proc. Natl. Acad. Sci. USA 78, 2120-2124). Although the reaction occurs in the absence of Fe(III), it is stimulated by added Fe (III). Inactivation required molecular oxygen and is partially inhibited by Mn(II), catalase, superoxide dismutase, and metal chelators, ethylenediaminetetraacetic acid and o-phenanthroline. Both the kinetics and the extent of glutamine synthetase inactivation differ when neutrophils are stimulated with phorbol esters compared with formylated peptides. Glutamine synthetase inactivation catalyzed by MFO systems is accompanied by the formation of protein carbonyl derivatives which form stable hydrazones when treated with 2,4-dinitrophenylhydrazine. Multiple carbonyl derivatives are formed in the soluble protein fraction of stimulated neutrophils and these derivatives collectively exhibit an absorbance spectrum similar to that of glutamine synthetase inactivated by liver microsomal cytochrome P-450 MFO system (K. Nakamura, C.N. Oliver, and E.R. Stadtman (1985) Arch. Biochem. Biophys. 240, 319-329).

  14. Markers of oxidative stress and erythrocyte antioxidant enzyme activity in older men and women with differing physical activity.

    Science.gov (United States)

    Rowiński, Rafał; Kozakiewicz, Mariusz; Kędziora-Kornatowska, Kornelia; Hübner-Woźniak, Elżbieta; Kędziora, Józef

    2013-11-01

    The aim of the present study was to examine the relationship between markers of oxidative stress and erythrocyte antioxidant enzyme activity and physical activity in older men and women. The present study included 481 participants (233 men and 248 women) in the age group 65-69 years (127 men and 125 women) and in the age group 90 years and over (106 men and 123 women). The classification of respondents by physical activity was based on answers to the question if, in the past 12 months, they engaged in any pastimes which require physical activity. The systemic oxidative stress status was assessed by measuring plasma iso-PGF2α and protein carbonyl concentration as well as erythrocyte antioxidant enzymes activity, i.e., superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). The concentration of plasma iso-PGF2α and protein carbonyls (CP) was lower in groups of younger men and women compared to the respective older groups. In all examined groups, physical activity resulted in decrease of these oxidative stress markers and simultaneously caused adaptive increase in the erythrocyte SOD activity. Additionally, in active younger men CAT, GPx, and GR activities were higher than in sedentary ones. In conclusion, oxidative stress increase is age-related, but physical activity can reduce oxidative stress markers and induce adaptive increase in the erythrocyte antioxidant enzyme activity, especially SOD, even in old and very old men and women.

  15. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids ), 2014. Scientific Opinion on Flavouring Group Evaluation 200 (FGE.200): 74 α , β -unsaturated aldehydes and precursors from subgroup 1.1.1 of FGE.19

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of 74 flavouring substances from subgroup 1.1.1 of FGE.19 in the Flavouring Group Evaluation 200 (FGE.200). The Flavour Industry has...... remains with respect to genotoxicity for the substances of this subgroup and their three representative substances. The Panel confirms, the need for an in vivo Comet assay performed in duodenum and liver for hex-2(trans)-enal [FL-no: 05.073]. For the two other representative substances of subgroup 1...

  16. Formation of Aldehyde and Ketone Compounds during Production and Storage of Milk Powder

    OpenAIRE

    Weijun Wang; Lanwei Zhang; Yanhua Li

    2012-01-01

    Certain aldehyde and ketone compounds can be used as indicators, at a molecular level, of the oxidized flavor of milk powder instead of sensory evaluation. This study investigated the formation of aldehyde and ketone compounds as affected by the heat-related processing and storage of milk powder. The compounds were extracted by solid phase microextraction fiber and determined using gas chromatography-mass spectrometry. In the results, higher contents of hexanal, 2-heptanone, octanal and 3-oct...

  17. Alcohol oxidizing enzymes and ethanol-induced cytotoxicity in rat pancreatic acinar AR42J cells.

    Science.gov (United States)

    Bhopale, Kamlesh K; Falzon, Miriam; Ansari, G A S; Kaphalia, Bhupendra S

    2014-04-01

    Alcoholic chronic pancreatitis (ACP) is a serious inflammatory disease causing significant morbidity and mortality. Due to lack of a suitable animal model, the underlying mechanism of ACP is poorly understood. Chronic alcohol abuse inhibits alcohol dehydrogenase (ADH) and facilitates nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs) in the pancreas frequently damaged during chronic ethanol abuse. Earlier, we reported a concentration-dependent formation of FAEEs and cytotoxicity in ethanol-treated rat pancreatic tumor (AR42J) cells, which express high FAEE synthase activity as compared to ADH and cytochrome P450 2E1. Therefore, the present study was undertaken to investigate the role of various ethanol oxidizing enzymes in ethanol-induced pancreatic acinar cell injury. Confluent AR42J cells were pre-treated with inhibitors of ADH class I and II [4-methylpyrazole (MP)] or class I, II, and III [1,10-phenanthroline (PT)], cytochrome P450 2E1 (trans-1,2-dichloroethylene) or catalase (sodium azide) followed by incubation with 800 mg% ethanol at 37°C for 6 h. Ethanol metabolism, cell viability, cytotoxicity (apoptosis and necrosis), cell proliferation status, and formation of FAEEs in AR42J cells were measured. The cell viability and cell proliferation rate were significantly reduced in cells pretreated with 1,10-PT + ethanol followed by those with 4-MP + ethanol. In situ formation of FAEEs was twofold greater in cells incubated with 1,10-PT + ethanol and ∼1.5-fold in those treated with 4-MP + ethanol vs. respective controls. However, cells treated with inhibitors of cytochrome P450 2E1 or catalase in combination of ethanol showed no significant changes either for FAEE formation, cell death or proliferation rate. Therefore, an impaired ADH class I-III catalyzed oxidation of ethanol appears to be a key contributing factor in ethanol-induced pancreatic injury via formation of nonoxidative metabolites of ethanol.

  18. Molecular Basis for Enzymatic Sulfite Oxidation -- HOW THREE CONSERVED ACTIVE SITE RESIDUES SHAPE ENZYME ACTIVITY

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, Susan; Rapson, Trevor; Johnson-Winters, Kayunta; Astashkin, Andrei; Enemark, John; Kappler, Ulrike

    2008-11-10

    Sulfite dehydrogenases (SDHs) catalyze the oxidation and detoxification of sulfite to sulfate, a reaction critical to all forms of life. Sulfite-oxidizing enzymes contain three conserved active site amino acids (Arg-55, His-57, and Tyr-236) that are crucial for catalytic competency. Here we have studied the kinetic and structural effects of two novel and one previously reported substitution (R55M, H57A, Y236F) in these residues on SDH catalysis. Both Arg-55 and His-57 were found to have key roles in substrate binding. An R55M substitution increased Km(sulfite)(app) by 2-3 orders of magnitude, whereas His-57 was required for maintaining a high substrate affinity at low pH when the imidazole ring is fully protonated. This effect may be mediated by interactions of His-57 with Arg-55 that stabilize the position of the Arg-55 side chain or, alternatively, may reflect changes in the protonation state of sulfite. Unlike what is seen for SDHWT and SDHY236F, the catalytic turnover rates of SDHR55M and SDHH57A are relatively insensitive to pH (~;;60 and 200 s-1, respectively). On the structural level, striking kinetic effects appeared to correlate with disorder (in SDHH57A and SDHY236F) or absence of Arg-55 (SDHR55M), suggesting that Arg-55 and the hydrogen bonding interactions it engages in are crucial for substrate binding and catalysis. The structure of SDHR55M has sulfate bound at the active site, a fact that coincides with a significant increase in the inhibitory effect of sulfate in SDHR55M. Thus, Arg-55 also appears to be involved in enabling discrimination between the substrate and product in SDH.

  19. Alcohol oxidizing enzymes and ethanol-induced cytotoxicity in rat pancreatic acinar AR42J cells

    Science.gov (United States)

    Bhopale, Kamlesh K.; Falzon, Miriam; Ansari, G. A. S.

    2016-01-01

    Alcoholic chronic pancreatitis (ACP) is a serious inflammatory disease causing significant morbidity and mortality. Due to lack of a suitable animal model, the underlying mechanism of ACP is poorly understood. Chronic alcohol abuse inhibits alcohol dehydrogenase (ADH) and facilitates nonoxidative metabolism of ethanol to fatty acid ethyl esters (FAEEs) in the pancreas frequently damaged during chronic ethanol abuse. Earlier, we reported a concentration-dependent formation of FAEEs and cytotoxicity in ethanol-treated rat pancreatic tumor (AR42J) cells, which express high FAEE synthase activity as compared to ADH and cytochrome P450 2E1. Therefore, the present study was undertaken to investigate the role of various ethanol oxidizing enzymes in ethanol-induced pancreatic acinar cell injury. Confluent AR42J cells were pre-treated with inhibitors of ADH class I and II [4-methylpyrazole (MP)] or class I, II, and III [1,10-phenanthroline (PT)], cytochrome P450 2E1 (trans-1,2-dichloroethylene) or catalase (sodium azide) followed by incubation with 800 mg% ethanol at 37°C for 6 h. Ethanol metabolism, cell viability, cytotoxicity (apoptosis and necrosis), cell proliferation status, and formation of FAEEs in AR42J cells were measured. The cell viability and cell proliferation rate were significantly reduced in cells pretreated with 1,10-PT + ethanol followed by those with 4-MP + ethanol. In situ formation of FAEEs was twofold greater in cells incubated with l,10-PT + ethanol and ~1.5-fold in those treated with 4-MP + ethanol vs. respective controls. However, cells treated with inhibitors of cytochrome P450 2E1 or catalase in combination of ethanol showed no significant changes either for FAEE formation, cell death or proliferation rate. Therefore, an impaired ADH class I—III catalyzed oxidation of ethanol appears to be a key contributing factor in ethanol-induced pancreatic injury via formation of nonoxidative metabolites of ethanol. PMID:24281792

  20. Amino Acid Residues Critical for the Specificity for Betaine Aldehyde of the Plant ALDH10 Isoenzyme Involved in the Synthesis of Glycine Betaine1[W][OA

    Science.gov (United States)

    Díaz-Sánchez, Ángel G.; González-Segura, Lilian; Mújica-Jiménez, Carlos; Rudiño-Piñera, Enrique; Montiel, Carmina; Martínez-Castilla, León P.; Muñoz-Clares, Rosario A.

    2012-01-01

    Plant Aldehyde Dehydrogenase10 (ALDH10) enzymes catalyze the oxidation of ω-primary or ω-quaternary aminoaldehydes, but, intriguingly, only some of them, such as the spinach (Spinacia oleracea) betaine aldehyde dehydrogenase (SoBADH), efficiently oxidize betaine aldehyde (BAL) forming the osmoprotectant glycine betaine (GB), which confers tolerance to osmotic stress. The crystal structure of SoBADH reported here shows tyrosine (Tyr)-160, tryptophan (Trp)-167, Trp-285, and Trp-456 in an arrangement suitable for cation-π interactions with the trimethylammonium group of BAL. Mutation of these residues to alanine (Ala) resulted in significant Km(BAL) increases and Vmax/Km(BAL) decreases, particularly in the Y160A mutant. Tyr-160 and Trp-456, strictly conserved in plant ALDH10s, form a pocket where the bulky trimethylammonium group binds. This space is reduced in ALDH10s with low BADH activity, because an isoleucine (Ile) pushes the Trp against the Tyr. Those with high BADH activity instead have Ala (Ala-441 in SoBADH) or cysteine, which allow enough room for binding of BAL. Accordingly, the mutation A441I decreased the Vmax/Km(BAL) of SoBADH approximately 200 times, while the mutation A441C had no effect. The kinetics with other ω-aminoaldehydes were not affected in the A441I or A441C mutant, demonstrating that the existence of an Ile in the second sphere of interaction of the aldehyde is critical for discriminating against BAL in some plant ALDH10s. A survey of the known sequences indicates that plants have two ALDH10 isoenzymes: those known to be GB accumulators have a high-BAL-affinity isoenzyme with Ala or cysteine in this critical position, while non GB accumulators have low-BAL-affinity isoenzymes containing Ile. Therefore, BADH activity appears to restrict GB synthesis in non-GB-accumulator plants. PMID:22345508

  1. The Genetics of Alcohol Metabolism: Role of Alcohol Dehydrogenase and Aldehyde Dehydrogenase Variants

    OpenAIRE

    Edenberg, Howard J

    2007-01-01

    The primary enzymes involved in alcohol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Both enzymes occur in several forms that are encoded by different genes; moreover, there are variants (i.e., alleles) of some of these genes that encode enzymes with different characteristics and which have different ethnic distributions. Which ADH or ALDH alleles a person carries influence his or her level of alcohol consumption and risk of alcoholism. Researchers to date pri...

  2. Redox and Chemical Activities of the Hemes in the Sulfur Oxidation Pathway Enzyme SoxAX*

    Science.gov (United States)

    Bradley, Justin M.; Marritt, Sophie J.; Kihlken, Margaret A.; Haynes, Kate; Hemmings, Andrew M.; Berks, Ben C.; Cheesman, Myles R.; Butt, Julea N.

    2012-01-01

    SoxAX enzymes couple disulfide bond formation to the reduction of cytochrome c in the first step of the phylogenetically widespread Sox microbial sulfur oxidation pathway. Rhodovulum sulfidophilum SoxAX contains three hemes. An electrochemical cell compatible with magnetic circular dichroism at near infrared wavelengths has been developed to resolve redox and chemical properties of the SoxAX hemes. In combination with potentiometric titrations monitored by electronic absorbance and EPR, this method defines midpoint potentials (Em) at pH 7.0 of approximately +210, −340, and −400 mV for the His/Met, His/Cys−, and active site His/CysS−-ligated heme, respectively. Exposing SoxAX to S2O42−, a substrate analog with Em ∼−450 mV, but not Eu(II) complexed with diethylene triamine pentaacetic acid (Em ∼−1140 mV), allows cyanide to displace the cysteine persulfide (CysS−) ligand to the active site heme. This provides the first evidence for the dissociation of CysS− that has been proposed as a key event in SoxAX catalysis. PMID:23060437

  3. Effect of commercially available green and black tea beverages on drug-metabolizing enzymes and oxidative stress in Wistar rats.

    Science.gov (United States)

    Yao, Hsien-Tsung; Hsu, Ya-Ru; Lii, Chong-Kuei; Lin, Ai-Hsuan; Chang, Keng-Hao; Yang, Hui-Ting

    2014-08-01

    The effect of commercially available green tea (GT) and black tea (BT) drinks on drug metabolizing enzymes (DME) and oxidative stress in rats was investigated. Male Wistar rats were fed a laboratory chow diet and GT or BT drink for 5 weeks. Control rats received de-ionized water instead of the tea drinks. Rats received the GT and BT drinks treatment for 5 weeks showed a significant increase in hepatic microsomal cytochrome P450 (CYP) 1A1 and CYP1A2, and a significant decrease in CYP2C, CYP2E1 and CYP3A enzyme activities. Results of immunoblot analyses of enzyme protein contents showed the same trend with enzyme activity. Significant increase in UDP-glucuronosyltransferase activity and reduced glutathione content in liver and lungs were observed in rats treated with both tea drinks. A lower lipid peroxide level in lungs was observed in rats treated with GT drink. Electrophoretic mobility shift assay revealed that both tea drinks decreased pregnane X receptor binding to DNA and increased nuclear factor-erythroid 2 p45-related factor 2 binding to DNA. These results suggest that feeding of both tea drinks to rats modulated DME activities and reduced oxidative stress in liver and lungs. GT drink is more effective on reducing oxidative stress than BT drink.

  4. Enzymes involved in the anaerobic oxidation of n-alkanes: from methane to long-chain paraffins

    Directory of Open Access Journals (Sweden)

    Amy V. Callaghan

    2013-05-01

    Full Text Available Anaerobic microorganisms play key roles in the biogeochemical cycling of methane and non-methane alkanes. To date, there appear to be at least three proposed mechanisms of anaerobic methane oxidation (AOM. The first pathway is mediated by consortia of archaeal anaerobic methane oxidizers and sulfate-reducing bacteria via ‘reverse methanogenesis’ and is catalyzed by a homologue of methyl-coenzyme M reductase. The second pathway is also mediated by anaerobic methane oxidizers and sulfate-reducing bacteria, wherein the archaeal members catalyze both methane oxidation and sulfate reduction and zero-valent sulfur is a key intermediate. The third AOM mechanism is a nitrite-dependent, intra-aerobic pathway described for the denitrifying bacterium, ‘Candidatus Methylomirabilis oxyfera.’ It is hypothesized that AOM proceeds via reduction of nitrite to nitric oxide, followed by the conversion of two nitric oxide molecules to dinitrogen and molecular oxygen. The latter can be used to functionalize the methane via a particulate methane monooxygenase. With respect to non-methane alkanes, there also appears to be novel mechanisms of activation. The most well-described pathway is the addition of non-methane alkanes across the double bond of fumarate to form alkyl-substituted succinates via the putative glycyl radical enzyme, alkylsuccinate synthase (also known as methylalkylsuccinate synthase. Other proposed mechanisms include anaerobic hydroxylation via ethylbenzene dehydrogenase-like enzymes and an ‘intra-aerobic’ denitrification pathway similar to that described for ‘M. oxyfera.’

  5. Angiotensin-I Converting Enzyme (ACE) Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora) Hydrolysates.

    Science.gov (United States)

    Ghanbari, Raheleh; Zarei, Mohammad; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

    2015-01-01

    In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora) hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8%) after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH) (56.00%) and ferrous ion-chelating (FIC) (59.00%) methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE) inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions. PMID:26690117

  6. Angiotensin-I Converting Enzyme (ACE Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora Hydrolysates

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2015-12-01

    Full Text Available In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8% after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH (56.00% and ferrous ion-chelating (FIC (59.00% methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions.

  7. The pathways of glutamate and glutamine oxidation by tumor cell mitochondria. Role of mitochondrial NAD(P)+-dependent malic enzyme.

    Science.gov (United States)

    Moreadith, R W; Lehninger, A L

    1984-05-25

    Little evidence has been available on the oxidative pathways of glutamine and glutamate, the major respiratory substrates of cancer cells. Glutamate formed from glutamine by phosphate-dependent glutaminase undergoes quantitative transamination by aerobic tumor mitochondria to yield aspartate. However, when malate is also added there is a pronounced decrease in aspartate production and a large formation of citrate and alanine, in both state 3 and 4 conditions. In contrast, addition of malate to normal rat heart, liver, or kidney mitochondria oxidizing glutamate causes a marked increase in aspartate production. Further analysis showed that extramitochondrial malate is oxidized almost quantitatively to pyruvate + CO2 by NAD(P)+-linked malic enzyme, present in the mitochondria of all tumors tested, but absent in heart, liver, and kidney mitochondria. On the other hand intramitochondrial malate generated from glutamate is oxidized quantitatively to oxalacetate by mitochondrial malate dehydrogenase of tumors. Acetyl-CoA derived from extramitochondrial malate via pyruvate and oxalacetate derived from glutamate via intramitochondrial malate are quantitatively converted into citrate, which is extruded. No evidence was found that malic enzyme of tumor mitochondria converts glutamate-derived malate into pyruvate as postulated in other reports. Possible mechanisms for the integration of mitochondrial malic enzyme and malate dehydrogenase activities in tumors are discussed.

  8. The pathways of glutamate and glutamine oxidation by tumor cell mitochondria. Role of mitochondrial NAD(P)+-dependent malic enzyme.

    Science.gov (United States)

    Moreadith, R W; Lehninger, A L

    1984-05-25

    Little evidence has been available on the oxidative pathways of glutamine and glutamate, the major respiratory substrates of cancer cells. Glutamate formed from glutamine by phosphate-dependent glutaminase undergoes quantitative transamination by aerobic tumor mitochondria to yield aspartate. However, when malate is also added there is a pronounced decrease in aspartate production and a large formation of citrate and alanine, in both state 3 and 4 conditions. In contrast, addition of malate to normal rat heart, liver, or kidney mitochondria oxidizing glutamate causes a marked increase in aspartate production. Further analysis showed that extramitochondrial malate is oxidized almost quantitatively to pyruvate + CO2 by NAD(P)+-linked malic enzyme, present in the mitochondria of all tumors tested, but absent in heart, liver, and kidney mitochondria. On the other hand intramitochondrial malate generated from glutamate is oxidized quantitatively to oxalacetate by mitochondrial malate dehydrogenase of tumors. Acetyl-CoA derived from extramitochondrial malate via pyruvate and oxalacetate derived from glutamate via intramitochondrial malate are quantitatively converted into citrate, which is extruded. No evidence was found that malic enzyme of tumor mitochondria converts glutamate-derived malate into pyruvate as postulated in other reports. Possible mechanisms for the integration of mitochondrial malic enzyme and malate dehydrogenase activities in tumors are discussed. PMID:6144677

  9. [Activity of oxidation-reduction enzymes in endotheliocytes of the intestinal hemomicrocirculatory bed under normal conditions and in portal hypertension].

    Science.gov (United States)

    Gaĭvoronskiĭ, I V; Tikhonova, L P; Chepur, S V; Nichiporuk, G I

    1997-01-01

    An original quantitative examination of oxidation-reduction enzymes activity in endotheliocytes of hemomicroclrculatory vessels of jejunum and rectum submucosal base in normal state and in portal hypertension was performed by the authors. Comparative analysis of the activity of the enzymes studied revealed different metabolic processes intensity in these organs, dependent on current hemodynamic conditions. Cytochemical changes in hemomicrocirculatory bed are consistent with structural reorganizations that arise in the wall of vessels studied, consist of several phases and may be used as an assessment criterion for defining the portal hypertension stage.

  10. Ageing of enteric neurons: oxidative stress, neurotrophic factors and antioxidant enzymes

    Directory of Open Access Journals (Sweden)

    Korsak Kris

    2012-08-01

    Full Text Available Abstract Background Ageing is associated with gastrointestinal dysfunction, which can have a major impact on quality of life of the elderly. A number of changes in the innervation of the gut during ageing have been reported, including neuronal loss and degenerative changes. Evidence indicates that reactive oxygen species (ROS are elevated in ageing enteric neurons, but that neurotrophic factors may reduce generation of neuronal ROS. Two such factors, glial cell line derived neurotrophic factor (GDNF and neurotrophin-3 (NT-3 have also been found to protect enteric neurons against oxidative stress induced cell death of enteric ganglion cells in vitro. We have investigated the possible roles of neurotrophic factors further, by examining their expression in the gut during ageing, and by analysing their effects on antioxidant enzyme production in cultures of enteric ganglion cells. Results Analysis of the expression of GDNF and its receptors c-Ret and GFR α − 1 in rat gut by RT-PCR showed that expression continues throughout life and into ageing, in both ad libitum(AL and calorically-restricted (CR animals. Levels of expression of GDNF and GFR α − 1 were elevated in 24 month AL animals compared to 24 month CR animals, and to 24 CR and 6 month control animals respectively. The related factor Neurturin and its receptor GFR α − 2 were also expressed throughout life, the levels of the GFR – α-2(b isoform were reduced in 24 m AL animals. Immunolabelling showed that c-Ret and GFR α − 1 proteins were expressed by myenteric neurons in ageing animals. GDNF, but not NT-3, was found to increase expression of Cu/Zn superoxide dismutase and catalase by cultured enteric ganglion cells. Conclusions The neurotrophic factors GDNF and neurturin and their receptors continue to be expressed in the ageing gut. Changes in the levels of expression of GDNF , GFR α-1 and GFR α-2(b isoform occurred in 24 m AL animals. GDNF, but not

  11. Molecular and Catalytic Properties of the Aldehyde Dehydrogenase of Gluconacetobacter diazotrophicus, a Quinoheme Protein Containing Pyrroloquinoline Quinone, Cytochrome b, and Cytochrome c▿

    Science.gov (United States)

    Gómez-Manzo, S.; Chavez-Pacheco, J. L.; Contreras-Zentella, M.; Sosa-Torres, M. E.; Arreguín-Espinosa, R.; Pérez de la Mora, M.; Membrillo-Hernández, J.; Escamilla, J. E.

    2010-01-01

    Several aldehyde dehydrogenase (ALDH) complexes have been purified from the membranes of acetic acid bacteria. The enzyme structures and the chemical nature of the prosthetic groups associated with these enzymes remain a matter of debate. We report here on the molecular and catalytic properties of the membrane-bound ALDH complex of the diazotrophic bacterium Gluconacetobacter diazotrophicus. The purified ALDH complex is a heterodimer comprising two subunits of 79.7 and 50 kDa, respectively. Reversed-phase high-pressure liquid chromatography (HPLC) and electron paramagnetic resonance spectroscopy led us to demonstrate, for the first time, the unequivocal presence of a pyrroloquinoline quinone prosthetic group associated with an ALDH complex from acetic acid bacteria. In addition, heme b was detected by UV-visible light (UV-Vis) spectroscopy and confirmed by reversed-phase HPLC. The smaller subunit bears three cytochromes c. Aliphatic aldehydes, but not formaldehyde, were suitable substrates. Using ferricyanide as an electron acceptor, the enzyme showed an optimum pH of 3.5 that shifted to pH 7.0 when phenazine methosulfate plus 2,6-dichlorophenolindophenol were the electron acceptors. Acetaldehyde did not reduce measurable levels of the cytochrome b and c centers; however, the dithionite-reduced hemes were conveniently oxidized by ubiquinone-1; this finding suggests that cytochrome b and the cytochromes c constitute an intramolecular redox sequence that delivers electrons to the membrane ubiquinone. PMID:20802042

  12. Oxidative stress enzymes in Ficus religiosa L.: biochemical, histochemical and anatomical evidences.

    Science.gov (United States)

    Smitha, R B; Bennans, Thomas; Mohankumar, C; Benjamin, Sailas

    2009-04-01

    In order to unveil the reasons behind the successful survival of Ficus religiosa L. grown under normal and adverse habitats (AH), i.e., on concrete roof tops were subjected to biochemical, histochemical and physiological studies with a focus on reactive oxygen species (ROS) and oxidative stress enzymes (OSE). The specific objectives were: to localize the OSE, peroxidase (POX) and catalase (CAT); to localize and quantify the main ROS, hydrogen peroxide (H(2)O(2)); to estimate the activities of POX, CAT and glycolate oxidase (GO); and to study the diurnal variations in stomatal activity by scanning electron microscopy (SEM). From the results, plants grown in AH showed 55% higher H(2)O(2) production with about 30% increase in POX activity. Of the three substrates tested for POX activity (guaiacol, ascorbate and o-dianisidine), o-dianisidine was found as the preferred substrate of F. religiosa POX with about 7-fold more activity over its counterparts. Cytosolic POX activity showed 11-fold increase over cell wall bound POX. Similarly, CAT activity in specimens from AH showed about 2-fold increase during day time. The physiological interaction between CAT and its substrate H(2)O(2) in the plant was determined by quantifying H(2)O(2) and assaying the CAT, in which CAT showed 4-fold increases in activity, especially during night. F. religiosa has higher amount of H(2)O(2) deposition during night than day time, which was in correlation high CAT activity during night, coupled with scotoactive opening of stomata as shown by the SEM images. Moreover, GO did not show much habitat-dependent variation. In toto, F. religiosa grown in AH showed elevated production of ROS and their scavenging OSE, which is the direct evidence for drought stress and also giving an insight into its evolution and ecological niche. PMID:19162506

  13. Structures and reaction pathways of the molybdenum centres of sulfite-oxidizing enzymes by pulsed EPR spectroscopy

    OpenAIRE

    Enemark, John H.; Astashkin, Andrei V.; Raitsimring, Arnold M.

    2008-01-01

    SOEs (sulfite-oxidizing enzymes) are physiologically vital and occur in all forms of life. During the catalytic cycle, the five-co-ordinate square pyramidal oxo-molybdenum active site passes through the Mo(V) state, and intimate details of the structure can be obtained from variable frequency pulsed EPR spectroscopy through the hyperfine and nuclear quadrupole interactions of nearby magnetic nuclei. By employing variable spectrometer operational frequencies, it is possible to optimize the mea...

  14. Significance of Lipid-Derived Reactive Aldehyde-Specific Immune Complexes in Systemic Lupus Erythematosus

    Science.gov (United States)

    Wang, Gangduo; Pierangeli, Silvia S.; Willis, Rohan; Gonzalez, Emilio B.; Petri, Michelle; Khan, M. Firoze

    2016-01-01

    Even though systemic lupus erythematosus (SLE) is associated with high morbidity and mortality rates among young and middle-aged women, the molecular mechanisms of disease pathogenesis are not fully understood. Previous studies from our laboratory suggested an association between oxidative stress and SLE disease activity (SLEDAI). To further assess the role of reactive oxygen species (ROS) in SLE, we examined the contribution of lipid-derived reactive aldehydes (LDRAs)-specific immune complexes in SLE. Sera from 60 SLE patients with varying SLEDAI and 32 age- and gender- matched healthy controls were analyzed for oxidative stress and related markers. Patients were divided into two groups based on their SLEDAI scores (<6 and ≥ 6). Both SLEDAI groups showed higher serum 4-hydroxynonenal (HNE)-/malondialdehyde (MDA)-protein adducts and their specific immune complexes (HNE-/MDA-specific ICs) together with IL-17 than the controls, but the levels were significantly greater in the high SLEDAI (≥ 6) group. Moreover, the serum levels of anti-oxidant enzymes Cu/Zn superoxide dismutase (SOD) and catalase (CAT) were significantly reduced in both patient groups compared to controls. Remarkably, for the first time, our data show that increased HNE-/MDA-specific ICs are positively associated with SLEDAI and elevated circulating immune complexes (CICs), suggesting a possible causal relationship among oxidative stress, LDRA-specific ICs and the development of SLE. Our findings, apart from providing firm support to an association between oxidative stress and SLE, also suggest that these oxidative stress markers, especially the HNE-/MDA-specific ICs, may be useful in evaluating the prognosis of SLE as well as in elucidating the mechanisms of disease pathogenesis. PMID:27749917

  15. Study on physico-chemical properties of dialdehyde yam starch with different aldehyde group contents

    International Nuclear Information System (INIS)

    Dialdehyde yam starches (DASs) are prepared and characterized. Compared with native starch, viscosity average molecular weight of DASs decreases, and the extent of degradation depends on content of the aldehyde groups. Fourier transform infrared (FT-IR) spectra confirm that the characteristic peak for C=O group at 1732 cm-1 is enhanced with the increasing of content of the aldehyde groups. Scanning electron microscopy (SEM) micrographs show that the surface of starch granules becomes wrinkled. X-ray diffraction (XRD) patterns clearly indicate that their crystallinity decreases with the increasing content of the aldehyde groups before they become amorphous at higher oxidation states. The experimental results of thermogravimetric analysis (TGA) show that DASs have poor stability as compared to native starch. With the increase in content of the aldehyde groups, the thermal stability of DAS declines gradually. According to the results of differential scanning calorimetry (DSC), gelatinization temperature (To and Tp) of DASs are increased, whereas the gelatinization enthalpy decreased.

  16. Novel Fluorescence Arginine Analogue as a Sensor for Direct Identification and Imaging of Nitric Oxide Synthase-like Enzymes in Plants.

    Science.gov (United States)

    Chang, Kang; Guo, Tongtong; Li, Pengfei; Liu, Yin; Xu, Yufang; Fang, Yuda; Qian, Xuhong

    2016-01-01

    Nitric oxide synthase like enzyme (NOS-like enzyme), which produces nitric oxide, participates in many biological processes. However it remains unidentified and highly controversial that plants do possess a NOS-like enzyme. In this paper, a novel arginine analogue NP1 was designed and developed for the direct identification and real time tracking of NOS-like enzymes in plant by fluorescence sensing. It could bind NOS-like enzyme efficiently and enter the cell successfully. In vivo fluorescence response results directly proved that NOS-like enzymes did exist in tobacco leaf and would be stimulated by pathogen infection, which also provided a useful chemical tool for the study of the function of NOS-like enzyme in plants. PMID:27586270

  17. Novel Fluorescence Arginine Analogue as a Sensor for Direct Identification and Imaging of Nitric Oxide Synthase-like Enzymes in Plants

    Science.gov (United States)

    Chang, Kang; Guo, Tongtong; Li, Pengfei; Liu, Yin; Xu, Yufang; Fang, Yuda; Qian, Xuhong

    2016-01-01

    Nitric oxide synthase like enzyme (NOS-like enzyme), which produces nitric oxide, participates in many biological processes. However it remains unidentified and highly controversial that plants do possess a NOS-like enzyme. In this paper, a novel arginine analogue NP1 was designed and developed for the direct identification and real time tracking of NOS-like enzymes in plant by fluorescence sensing. It could bind NOS-like enzyme efficiently and enter the cell successfully. In vivo fluorescence response results directly proved that NOS-like enzymes did exist in tobacco leaf and would be stimulated by pathogen infection, which also provided a useful chemical tool for the study of the function of NOS-like enzyme in plants. PMID:27586270

  18. Novel Fluorescence Arginine Analogue as a Sensor for Direct Identification and Imaging of Nitric Oxide Synthase-like Enzymes in Plants

    Science.gov (United States)

    Chang, Kang; Guo, Tongtong; Li, Pengfei; Liu, Yin; Xu, Yufang; Fang, Yuda; Qian, Xuhong

    2016-09-01

    Nitric oxide synthase like enzyme (NOS-like enzyme), which produces nitric oxide, participates in many biological processes. However it remains unidentified and highly controversial that plants do possess a NOS-like enzyme. In this paper, a novel arginine analogue NP1 was designed and developed for the direct identification and real time tracking of NOS-like enzymes in plant by fluorescence sensing. It could bind NOS-like enzyme efficiently and enter the cell successfully. In vivo fluorescence response results directly proved that NOS-like enzymes did exist in tobacco leaf and would be stimulated by pathogen infection, which also provided a useful chemical tool for the study of the function of NOS-like enzyme in plants.

  19. Involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of Reaumuria soongorica to salt stress

    Institute of Scientific and Technical Information of China (English)

    YuBing Liu; Bo Cao; MeiLing Liu

    2013-01-01

    Reaumuria soongorica is a short woody shrub widely found in semi-arid areas of China. It can survive severe environ-mental stress including high salinity in its natural habitat. Thus, we investigated the involvement of anti-oxidative enzymes, photosynthetic pigments and flavonoid metabolism in the adaptation of R. soongorica to saline environments. R. soon-gorica was treated with 0, 100, 200 and 400 mM NaCl solutions for 14 days. Soil salt content increased significantly by watering with high content of NaCl solution, and no variation between 8 and 14 days during treatment. The levels of pe-roxidation of lipid membranes (measured by malondialdehyde content) and the activities of three antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX)) increased under salt stress. Chlorophyll and carotenoid content decreased with increasing salt content. The ratio of Chl a/Chl b and carotenoid/Chl exhibited sig-nificant increase under 400 mM NaCl. However, total flavonoid and anthocyanin contents and key enzyme activities in the flavonoid pathway including phenylalanine ammonialyase (PAL) and Chalcone isomerase (CHI) decreased under salt stress. These findings possibly suggest that R. soongorica has an adaptation protection mechanism against salt-induced oxidative damage by inducing the activity of antioxidant enzymes and maintaining a steady level of carotenoid/Chl.

  20. Ultrasound-assisted extraction and characterization of hydrolytic and oxidative enzymes produced by solid state fermentation.

    Science.gov (United States)

    Szabo, Orsolya Erzsebet; Csiszar, Emilia; Toth, Karolina; Szakacs, George; Koczka, Bela

    2015-01-01

    Ligninolytic and hydrolytic enzymes were produced with six selected fungi on flax substrate by solid state fermentation (SSF). The extracellular enzyme production of the organisms in two SSF media was evaluated by measuring the soluble protein concentration and the filter paper, endoxylanase, 1,4-β-d-glucosidase, 1,4-β-d-endoglucanase, polygalacturonase, lignin peroxidase, manganese peroxidase and laccase activities of the clear culture solutions produced by conventional extraction from the SSF materials. The SSF material of the best enzyme producer (Trichoderma virens TUB F-498) was further investigated to enhance the enzyme recovery by low frequency ultrasound treatment. Performance of both the original and ultrasound macerated crude enzyme mixtures was evaluated in degradation of the colored lignin-containing and waxy materials of raw linen fabric. Results proved that sonication (at 40%, 60% and 80% amplitudes, for 60min) did not result in reduction in the filter paper, lignin peroxidase and laccase activities of the crude enzyme solution, but has a significant positive effect on the efficiency of enzyme extraction from the SSF material. Depending on the parameters of sonication, the enzyme activities in the extracts obtained can be increased up to 129-413% of the original activities measured in the control extracts recovered by a common magnetic stirrer. Sonication also has an effect on both the enzymatic removal of the lignin-containing color materials and hydrophobic surface layer from the raw linen.

  1. Measuring Intracellular Enzyme Concentrations: Assessing the Effect of Oxidative Stress on the Amount of Glyoxalase I

    Science.gov (United States)

    Miranda, Hugo Vicente; Ferreira, Antonio E. N.; Quintas, Alexandre; Cordeiro, Carlos; Freire, Ana Ponces

    2008-01-01

    Enzymology is one of the fundamental areas of biochemistry and involves the study of the structure, kinetics, and regulation of enzyme activity. Research in this area is often conducted with purified enzymes and extrapolated to "in vivo" conditions. The specificity constant, k[subscript S], is the ratio between k[subscript cat] (the catalytic…

  2. INVOLVEMENT OF OXIDATIVE STRESS IN THE PATHOGENESIS OF SCHIZOPHRENIA:FOCUS ON NOX ENZYMES

    OpenAIRE

    Schiavone, Stefania

    2011-01-01

    The imbalance between the production of reactive oxygen species (ROS) and the cellular antioxidant defence, determines a situation called “oxidative stress”. ROS react and oxidize cellular components, such as proteins or DNA, leading to cell death and severe tissue damage. The central nervous system (CNS) is particularly sensitive to oxidative stress because of high oxygen consumption, low antioxidant defense and abundance of lipids, which are prone to oxidation. For this reaso...

  3. Separation and Purification of Betaine Aldehyde Dehydrogenase from Wild Suaeda liaotungensis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    High active betaine aldehyde dehydrogenase (BADH, EC 1.2.1.8) is found in wild Suaeda liaotungensis. The enzyme is purified 206-fold with recovery of 1.5%. It have a specific activity of 2363 nmol/min*mg protein and the molecular mass of each subunit is 64.5 kDa as determined by SDS-PAGE.

  4. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry.

    Science.gov (United States)

    Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-05-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat. PMID:26954148

  5. Antioxidant Enzyme Activity, Iron Content and Lipid Oxidation of Raw and Cooked Meat of Korean Native Chickens and Other Poultry.

    Science.gov (United States)

    Muhlisin; Utama, Dicky Tri; Lee, Jae Ho; Choi, Ji Hye; Lee, Sung Ki

    2016-05-01

    This study was conducted to observe antioxidant enzyme activity, iron content and lipid oxidation of Korean native chickens and other poultry. The breast and thigh meat of three Korean native chicken breeds including Woorimatdak, Hyunin black and Yeonsan ogye, and three commercial poultry breeds including the broiler, White Leghorn and Pekin duck (Anasplatyrhyncos domesticus) were studied. The analyses of the antioxidant enzymes activity, iron content and lipid oxidation were performed in raw and cooked samples. The activity of catalase (CAT) in the thigh meat was higher than that of the breast meat of three Korean native chickens and the broiler, respectively. The activity of glutathione peroxidase (GPx) in the uncooked thigh meat of three Korean native chickens was higher than that of the breasts. The breast meat of Woorimatdak and Pekin duck had higher superoxide dismutase (SOD) activity than the others, while only the thigh meat of Pekin duck had the highest activity. Cooking inactivated CAT and decreased the activity of GPx and SOD. The thigh meat of Woorimatdak, White Leghorn, Yeonsan ogye and Hyunin black contained more total iron than the breast meat of those breeds. The heme-iron lost during cooking ranged from 3.2% to 14.8%. It is noted that the thigh meat had higher thiobarbituric acid reactive substances values than the breast in all chicken breeds. Though Woorimatdak showed higher antioxidant enzyme activity and lower released-iron percentage among Korean native chickens, no differences were found on lipid oxidation. We confirm that the dark meat of poultry exhibited higher antioxidant enzyme activity and contained more iron than the white meat.

  6. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

    Directory of Open Access Journals (Sweden)

    Feng-Xia Tian

    Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  7. Immobilization of Enzymes by Electrochemical and Chemical Oxidative Polymerization of L-DOPA to Fabricate Amperometric Biosensors and Biofuel Cells.

    Science.gov (United States)

    Dai, Mengzhen; Sun, Lingen; Chao, Long; Tan, Yueming; Fu, Yingchun; Chen, Chao; Xie, Qingji

    2015-05-27

    Electrochemical/chemical oxidative synthesis and biosensing/biofuel cell applications of poly(L-DOPA) (PD) are studied versus polydopamine (PDA) as a recent hotspot biomaterial. The enzyme electrode developed by coelectrodeposition of PD and glucose oxidase (GOx), uricase, or tyrosinase shows biosensing performance superior to that of the corresponding PDA-based enzyme electrode. The chemical oxidative polymerization of L-DOPA (PDC) by NaAuCl4 in GOx-containing neutral aqueous solution is used to immobilize GOx and gold nanoparticles (AuNPs). The thus-prepared chitosan (CS)/GOx-PDC-AuNPs/Au(plate)/Au electrode working in the first-generation biosensing mode responds linearly to glucose concentration with a sensitivity of 152 μA mM(-1) cm(-2), which is larger than those of the CS/GOx-PDAC-AuNPs/Au(plate)/Au electrode, the CS/GOx-poly(3-anilineboronic acid) (PABA)-AuNPs/Au(plate)/Au electrode, and the most reported GOx-based enzyme electrodes. This PDC-based enzyme electrode also works well in the second-generation biosensing mode and as an excellent bioanode in biofuel cell construction, probably because PD as an amino acid polymer has the higher biocompatibility and the more favorable affinity to the enzyme than PDA. The PD material of great convenience in synthesis, outstanding biocompatibility for preparing high-performance bionanocomposites, and strong capability of multifunctional coatings on many surfaces may find wide applications in diversified fields including biotechnology and surface-coating. PMID:25938891

  8. Increased Oxidative Stress and Imbalance in Antioxidant Enzymes in the Brains of Alloxan-Induced Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Luciane B. Ceretta

    2012-01-01

    Full Text Available Diabetes Mellitus (DM is associated with pathological changes in the central nervous system (SNC as well as alterations in oxidative stress. Thus, the main objective of this study was to evaluate the effects of the animal model of diabetes induced by alloxan on memory and oxidative stress. Diabetes was induced in Wistar rats by using a single injection of alloxan (150 mg/kg, and fifteen days after induction, the rats memory was evaluated through the use of the object recognition task. The oxidative stress parameters and the activity of antioxidant enzymes, superoxide dismutase (SOD, and catalase (CAT were measured in the rat brain. The results showed that diabetic rats did not have alterations in their recognition memory. However, the results did show that diabetic rats had increases in the levels of superoxide in the prefrontal cortex, and in thiobarbituric acid reactive species (TBARS production in the prefrontal cortex and in the amygdala in submitochondrial particles. Also, there was an increase in protein oxidation in the hippocampus and striatum, and in TBARS oxidation in the striatum and amygdala. The SOD activity was decreased in diabetic rats in the striatum and amygdala. However, the CAT activity was increased in the hippocampus taken from diabetic rats. In conclusion, our findings illustrate that the animal model of diabetes induced by alloxan did not cause alterations in the animals’ recognition memory, but it produced oxidants and an imbalance between SOD and CAT activities, which could contribute to the pathophysiology of diabetes.

  9. Mitochondrial DNA (mtDNA haplogroups and serum levels of anti-oxidant enzymes in patients with osteoarthritis

    Directory of Open Access Journals (Sweden)

    Fernandez-Moreno Mercedes

    2011-11-01

    Full Text Available Abstract Background Oxidative stress play a main role in the initiation and progression of the OA disease and leads to the degeneration of mitochondria. To prevent this, the chondrocytes possess a well-coordinated enzymatic antioxidant system. Besides, the mitochondrial DNA (mtDNA haplogroups are associated with the OA disease. Thus, the main goal of this work is to assess the incidence of the mtDNA haplogroups on serum levels of two of the main antioxidant enzymes, Manganese Superoxide Dismutase (Mn-SOD or SOD2 and catalase, and to test the suitability of these two proteins for potential OA-related biomarkers. Methods We analyzed the serum levels of SOD2 and catalase in 73 OA patients and 77 healthy controls carrying the haplogroups J, U and H, by ELISA assay. Knee and hip radiographs were classified according to Kellgren and Lawrence (K/L scoring from Grade 0 to Grade IV. Appropriate statistical analyses were performed to test the effects of clinical variables, including gender, body mass index (BMI, age, smoking status, diagnosis, haplogroups and radiologic K/L grade on serum levels of these enzymes. Results Serum levels of SOD2 appeared statistically increased in OA patients when compared with healthy controls (p Conclusions The increased levels of SOD2 in OA patients indicate an increased oxidative stress OA-related, therefore this antioxidant enzyme could be a suitable candidate biomarker for diagnosis of OA. Mitochondrial haplogroups significantly correlates with serum levels of catalase

  10. Role of oxidant stress in rheumatoid arthritis

    OpenAIRE

    GS, Lekshmi; BR, Suchit Roy; K., Parvathy; K., Geetha Damodaran

    2015-01-01

    Oxygen derived free radicals have been implicated in the causation of Rheumatoid arthritis (RA) [1].In this study, evidence of free radical injury and oxidative stress in patients with RA is compared with healthy subjects by estimating superoxide dismutase (SOD) and catalase, which are anti-oxidant enzymes in RBCs, Glucose 6 Phosphate Dehydrogenase (G6PD) in RBCs and serum Malon-di-aldehyde (MDA) levels. Serum MDA levels in RA could be used as a biochemical marker of disease activity and for ...

  11. Biossensor enzimático para detecção de fungicidas ditiocarbamatos: estudo cinético da enzima aldeído desidrogenase e otimização do biossensor Enzymatic biosensor for the detection of dithiocarbamate fungicides: kinetic study of aldehyde dehydrogenase enzyme and biosensor optimization

    Directory of Open Access Journals (Sweden)

    Roberval Soares Lima

    2007-02-01

    Full Text Available Initially, all major factors that affect the rate of the AldH-catalyzed reaction (enzyme concentration, substrate concentration, temperature and pH were investigated. Optimal activity was observed between pH values of 7.5 and 9.5 in the temperature range of 25 to 50 ºC. Kinetic parameters, such as Km (2.92 µmol L-1 and Vmax (1.33 10-2 µmol min-1 demonstrate a strong enzyme-substrate affinity. The sensors were based on screen-printed electrodes modified with the Meldola Blue-Reinecke salt (MBRS combination. Operational conditions (NAD+ and substrate contents, enzyme loading and response time were optimized. Also, two enzyme immobilization procedures were tested: entrapment in poly(vinyl alcohol bearing styrylpyridinium groups (PVA-SbQ and crosslinking with glutaraldehyde. Chronoamperometry was employed to observe the biosensor responses during enzymatic hydrolysis of propionaldehyde and also to construct inhibition curves with maneb and zineb fungicides. Best results were found with the following conditions: [NAD+] = 0.25 mmol L-1; [propionaldehyde] = 80 µmol L-1; enzyme loading = 0.8 U per electrode; response time = 10 min, and inhibition time = 10 min. Current intensities around 103 ± 13 nA with the sensors and good stability was obtained for both immobilization procedures. Detection limits, calculated using 10% inhibition were 31.5 µg L-1 and 35 µg L-1 for maneb and zineb, respectively. Results obtained with other MBRS-modified electrodes consisting of mono and bi-enzymic sensors were compared. The ability to catalyze NADH oxidation by MB was also highlighted.

  12. Thiocyanate hydrolase, the primary enzyme initiating thiocyanate degradation in the novel obligately chemolithoautotrophic halophilic sulfur-oxidizing bacterium Thiohalophilus thiocyanoxidans.

    Science.gov (United States)

    Bezsudnova, Ekaterina Yu; Sorokin, Dimitry Yu; Tikhonova, Tamara V; Popov, Vladimir O

    2007-12-01

    Thiohalophilus thiocyanoxidans is a first halophilic sulfur-oxidizing chemolithoautotrophic bacterium capable of growth with thiocyanate as an electron donor at salinity up to 4 M NaCl. The cells, grown with thiocyanate, but not with thiosulfate, contained an enzyme complex hydrolyzing thiocyanate to sulfide and ammonia under anaerobic conditions with carbonyl sulfide as an intermediate. Despite the fact of utilization of the , high cyanase activity was also detected in thiocyanate-induced cells. Three-stage column chromotography resulted in a highly purified thiocyanate-hydrolyzing protein with an apparent molecular mass of 140 kDa that consists of three subunits with masses 17, 19 and 29 kDa. The enzyme is a Co,Fe-containing protein resembling on its function and subunit composition the enzyme thiocyanate hydrolase from the Betaproteobacterium Thiobacillus thioparus. Cyanase, copurified with thiocyanate hydrolase, is a bisubstrate multisubunit enzyme with an apparent subunit molecular mass of 14 kDa. A possible role of cyanase in thiocyanate degradation by T. thiocyanoxidans is discussed.

  13. Enzyme-functionalized vascular grafts catalyze in-situ release of nitric oxide from exogenous NO prodrug.

    Science.gov (United States)

    Wang, Zhihong; Lu, Yaxin; Qin, Kang; Wu, Yifan; Tian, Yingping; Wang, Jianing; Zhang, Jimin; Hou, Jingli; Cui, Yun; Wang, Kai; Shen, Jie; Xu, Qingbo; Kong, Deling; Zhao, Qiang

    2015-07-28

    Nitric oxide (NO) is an important signaling molecule in cardiovascular system, and the sustained release of NO by endothelial cells plays a vital role in maintaining patency and homeostasis. In contrast, lack of endogenous NO in artificial blood vessel is believed to be the main cause of thrombus formation. In this study, enzyme prodrug therapy (EPT) technique was employed to construct a functional vascular graft by immobilization of galactosidase on the graft surface. The enzyme-functionalized grafts exhibited excellent catalytic property in decomposition of the exogenously administrated NO prodrug. Localized and on-demand release of NO was demonstrated by in vitro release assay and fluorescent probe tracing in an ex vivo model. The immobilized enzyme retained catalytic property even after subcutaneous implantation of the grafts for one month. The functional vascular grafts were implanted into the rat abdominal aorta with a 1-month monitoring period. Results showed effective inhibition of thrombus formation in vivo and enhancement of vascular tissue regeneration and remodeling on the grafts. Thus, we create an enzyme-functionalized vascular graft that can catalyze prodrug to release NO locally and sustainably, indicating that this approach may be useful to develop new cell-free vascular grafts for treatment of vascular diseases. PMID:26004323

  14. Site-Specific, Covalent Immobilization of Dehalogenase ST2570 Catalyzed by Formylglycine-Generating Enzymes and Its Application in Batch and Semi-Continuous Flow Reactors.

    Science.gov (United States)

    Jian, Hui; Wang, Yingwu; Bai, Yan; Li, Rong; Gao, Renjun

    2016-01-01

    Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly) residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 from Sulfolobus tokodaii was used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ) exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570. PMID:27409601

  15. Site-Specific, Covalent Immobilization of Dehalogenase ST2570 Catalyzed by Formylglycine-Generating Enzymes and Its Application in Batch and Semi-Continuous Flow Reactors

    Directory of Open Access Journals (Sweden)

    Hui Jian

    2016-07-01

    Full Text Available Formylglycine-generating enzymes can selectively recognize and oxidize cysteine residues within the sulfatase sub motif at the terminus of proteins to form aldehyde-bearing formylglycine (FGly residues, and are normally used in protein labeling. In this study, an aldehyde tag was introduced to proteins using formylglycine-generating enzymes encoded by a reconstructed set of the pET28a plasmid system for enzyme immobilization. The haloacid dehalogenase ST2570 from Sulfolobus tokodaii was used as a model enzyme. The C-terminal aldehyde-tagged ST2570 (ST2570CQ exhibited significant enzymological properties, such as new free aldehyde groups, a high level of protein expression and improved enzyme activity. SBA-15 has widely been used as an immobilization support for its large surface and excellent thermal and chemical stability. It was functionalized with amino groups by aminopropyltriethoxysilane. The C-terminal aldehyde-tagged ST2570 was immobilized to SBA-15 by covalent binding. The site-specific immobilization of ST2570 avoided the chemical denaturation that occurs in general covalent immobilization and resulted in better fastening compared to physical adsorption. The site-specific immobilized ST2570 showed 3-fold higher thermal stability, 1.2-fold higher catalytic ability and improved operational stability than free ST2570. The site-specific immobilized ST2570 retained 60% of its original activity after seven cycles of batch operation, and it was superior to the ST2570 immobilized to SBA-15 by physical adsorption, which loses 40% of its original activity when used for the second time. It is remarkable that the site-specific immobilized ST2570 still retained 100% of its original activity after 10 cycles of reuse in the semi-continuous flow reactor. Overall, these results provide support for the industrial-scale production and application of site-specific, covalently immobilized ST2570.

  16. The Anopheles gambiae oxidation resistance 1 (OXR1 gene regulates expression of enzymes that detoxify reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Giovanna Jaramillo-Gutierrez

    Full Text Available BACKGROUND: OXR1 is an ancient gene, present in all eukaryotes examined so far that confers protection from oxidative stress by an unknown mechanism. The most highly conserved region of the gene is the carboxyl-terminal TLDc domain, which has been shown to be sufficient to prevent oxidative damage. METHODOLOGY/PRINCIPAL FINDINGS: OXR1 has a complex genomic structure in the mosquito A. gambiae, and we confirm that multiple splice forms are expressed in adult females. Our studies revealed that OXR1 regulates the basal levels of catalase (CAT and glutathione peroxidase (Gpx expression, two enzymes involved in detoxification of hydrogen peroxide, giving new insight into the mechanism of action of OXR1. Gene silencing experiments indicate that the Jun Kinase (JNK gene acts upstream of OXR1 and also regulates expression of CAT and GPx. Both OXR1 and JNK genes are required for adult female mosquitoes to survive chronic oxidative stress. OXR1 silencing decreases P. berghei oocyst formation. Unexpectedly, JNK silencing has the opposite effect and enhances Plasmodium infection in the mosquito, suggesting that JNK may also mediate some, yet to be defined, antiparasitic response. CONCLUSION: The JNK pathway regulates OXR1 expression and OXR1, in turn, regulates expression of enzymes that detoxify reactive oxygen species (ROS in Anopheles gambiae. OXR1 silencing decreases Plasmodium infection in the mosquito, while JNK silencing has the opposite effect and enhances infection.

  17. Response of oxidative stress and isoflavone treatment on superoxide dismutase enzyme activities and lipid peroxidation in rat’s liver

    Directory of Open Access Journals (Sweden)

    Suarsana IN

    2013-06-01

    Full Text Available Oxidative stress is defined as over-production of free radicals which lead to cells damage, pathological condition and cell death. The objective of this study was to analyze respond of oxidative stress and isoflavone treatment on superoxide dismutase (SOD enzyme activities and lipid peroxidation in rat liver. A total of fifteen male Spraque Dawley rats were used in this study. They were sub-divided into three groups; (1 a negative control group, (2 a stress oxidative group, and (3 treatment by stress condition followed by treatment with isoflavone. Stress condition was achieved by five days fasting together with swimming for 5 mins/day and only drinking water ad libitum. Isoflavone was orally administrated on a dose of 1 mg/200g bw/day for five days. At the end of the experiment, rats were sacrificed by anesthesia. Liver was collected for analysis of SOD enzyme activities, SOD immunohistochemical analysis, and malondialdehyde (MDA level. Result showed that stress condition increase free radicals that showed by decreased SOD activity, and increased MDA level. Isoflavone treatment could get over reduction of SOD and prevented increase of MDA level in the liver of rats under stress conditions.

  18. The Anopheles gambiae Oxidation Resistance 1 (OXR1) Gene Regulates Expression of Enzymes That Detoxify Reactive Oxygen Species

    Science.gov (United States)

    Jaramillo-Gutierrez, Giovanna; Molina-Cruz, Alvaro; Kumar, Sanjeev; Barillas-Mury, Carolina

    2010-01-01

    Background OXR1 is an ancient gene, present in all eukaryotes examined so far that confers protection from oxidative stress by an unknown mechanism. The most highly conserved region of the gene is the carboxyl-terminal TLDc domain, which has been shown to be sufficient to prevent oxidative damage. Methodology/Principal Findings OXR1 has a complex genomic structure in the mosquito A. gambiae, and we confirm that multiple splice forms are expressed in adult females. Our studies revealed that OXR1 regulates the basal levels of catalase (CAT) and glutathione peroxidase (Gpx) expression, two enzymes involved in detoxification of hydrogen peroxide, giving new insight into the mechanism of action of OXR1. Gene silencing experiments indicate that the Jun Kinase (JNK) gene acts upstream of OXR1 and also regulates expression of CAT and GPx. Both OXR1 and JNK genes are required for adult female mosquitoes to survive chronic oxidative stress. OXR1 silencing decreases P. berghei oocyst formation. Unexpectedly, JNK silencing has the opposite effect and enhances Plasmodium infection in the mosquito, suggesting that JNK may also mediate some, yet to be defined, antiparasitic response. Conclusion The JNK pathway regulates OXR1 expression and OXR1, in turn, regulates expression of enzymes that detoxify reactive oxygen species (ROS) in Anopheles gambiae. OXR1 silencing decreases Plasmodium infection in the mosquito, while JNK silencing has the opposite effect and enhances infection. PMID:20567517

  19. Light-driven artificial enzymes for selective oxidation of guanosine triphosphate using water-soluble POSS network polymers.

    Science.gov (United States)

    Jeon, Jong-Hwan; Tanaka, Kazuo; Chujo, Yoshiki

    2014-09-01

    The light-driven artificial enzymes were constructed to realize unnatural reactions concerning bio-significant molecules. In this manuscript, the guanosine triphosphate (GTP)-selective oxidation is reported using the network polymers composed of polyhedral oligomeric silsesquioxane (POSS). We synthesized the water-soluble POSS network polymer containing the naphthyridine ligands to capture GTP inside the networks and the ruthenium complexes to oxidize the captured GTP under light irradiation. Initially, the binding affinities of the guanosine nucleosides to the naphthyridine ligand inside the POSS network polymer were evaluated from the emission quenching experiments. Accordingly, it was observed that the naphthyridine ligand can form the stable complex only with GTP (K(a) = 5.5 × 10(6) M(-1)). These results indicate that only GTP can be captured by the network polymer. Next, the photo-catalytic activity of the ruthenium complex-modified POSS network polymer was investigated. Finally, it was revealed that the network polymer can decompose GTP efficiently under light irradiation. This is the first example, to the best of our knowledge, to offer not only the GTP-selective host polymers but also the light-driven artificial enzyme for GTP oxidation. PMID:25026217

  20. Respiratory burst enzymes, pro-oxidants and antioxidants status in Bangladeshi population with β-thalassemia major

    Directory of Open Access Journals (Sweden)

    Md. Faruk Hossain

    2015-01-01

    Full Text Available Background: Oxidative stress is intimately associated with many diseases, including β-thalassemia. Aim: The study was to estimate the status of respiratory burst enzymes, pro-oxidants, and antioxidants in β-thalassemia major patients in Bangladesh and to compare with apparently healthy individuals. Materials and Methods: A total of 49 subjects were recruited which included 25 patients (age range 5 to 40 years with β-thalassemia major and 24 controls (age and sex matched. Superoxide dismutase (SOD and catalase (CAT represented respiratory burst enzymes; malondialdehyde (MDA, lipid hydroperoxide (LHP, and xanthine oxidase (XO were measured as pro-oxidants; and glutathione S transferase (GST, vitamin C (Vit.C, and glutathione (GSH were the measured antioxidants. Results: The activity of SOD was significantly (P < 0.001 increased by about 79% and the activity of CAT was significantly (P < 0.001 decreased by more than 34% in the blood of β-thalassemia major patients compared to the control group. The content of pro-oxidants such as MDA, LHP, and XO was significantly (P < 0.001 higher in patients by about 228%, 241.3% and 148.1% respectively compared to control group. The level of GSH and Vit.C were significantly (P = 0.000 decreased in patients by about 59% and 81% versus the healthy group, respectively; and GST activity was significantly (P < 0.001 declined by 44.25% in patients group. Conclusion: β-thalassemia major patients demonstrate raised oxidative stress compared to healthy subjects.

  1. Impact of L-FABP and glucose on polyunsaturated fatty acid induction of PPARα-regulated β-oxidative enzymes.

    Science.gov (United States)

    Petrescu, Anca D; Huang, Huan; Martin, Gregory G; McIntosh, Avery L; Storey, Stephen M; Landrock, Danilo; Kier, Ann B; Schroeder, Friedhelm

    2013-02-01

    Liver fatty acid binding protein (L-FABP) is the major soluble protein that binds very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) in hepatocytes. However, nothing is known about L-FABP's role in n-3 PUFA-mediated peroxisome proliferator activated receptor-α (PPARα) transcription of proteins involved in long-chain fatty acid (LCFA) β-oxidation. This issue was addressed in cultured primary hepatocytes from wild-type, L-FABP-null, and PPARα-null mice with these major findings: 1) PUFA-mediated increase in the expression of PPARα-regulated LCFA β-oxidative enzymes, LCFA/LCFA-CoA binding proteins (L-FABP, ACBP), and PPARα itself was L-FABP dependent; 2) PPARα transcription, robustly potentiated by high glucose but not maltose, a sugar not taken up, correlated with higher protein levels of these LCFA β-oxidative enzymes and with increased LCFA β-oxidation; and 3) high glucose altered the potency of n-3 relative to n-6 PUFA. This was not due to a direct effect of glucose on PPARα transcriptional activity nor indirectly through de novo fatty acid synthesis from glucose. Synergism was also not due to glucose impacting other signaling pathways, since it was observed only in hepatocytes expressing both L-FABP and PPARα. Ablation of L-FABP or PPARα as well as treatment with MK886 (PPARα inhibitor) abolished/reduced PUFA-mediated PPARα transcription of these genes, especially at high glucose. Finally, the PUFA-enhanced L-FABP distribution into nuclei with high glucose augmentation of the L-FABP/PPARα interaction reveals not only the importance of L-FABP for PUFA induction of PPARα target genes in fatty acid β-oxidation but also the significance of a high glucose enhancement effect in diabetes.

  2. Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant

    Science.gov (United States)

    Mohamed-Hussein, Zeti-Azura; Ng, Chyan Leong

    2016-01-01

    Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that’s highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity

  3. Neonatal hyperglycemia induces oxidative stress in the rat brain: the role of pentose phosphate pathway enzymes and NADPH oxidase.

    Science.gov (United States)

    Rosa, Andrea Pereira; Jacques, Carlos Eduardo Dias; de Souza, Laila Oliveira; Bitencourt, Fernanda; Mazzola, Priscila Nicolao; Coelho, Juliana Gonzales; Mescka, Caroline Paula; Dutra-Filho, Carlos Severo

    2015-05-01

    Recently, the consequences of diabetes on the central nervous system (CNS) have received great attention. However, the mechanisms by which hyperglycemia affects the central nervous system remain poorly understood. In addition, recent studies have shown that hyperglycemia induces oxidative damage in the adult rat brain. In this regard, no study has assessed oxidative stress as a possible mechanism that affects the brain normal function in neonatal hyperglycemic rats. Thus, the present study aimed to investigate whether neonatal hyperglycemia elicits oxidative stress in the brain of neonate rats subjected to a streptozotocin-induced neonatal hyperglycemia model (5-day-old rats). The activities of glucose-6-phosphate-dehydrogenase (G6PD), 6-phosphogluconate-dehydrogenase (6-PGD), NADPH oxidase (Nox), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), the production of superoxide anion, the thiobarbituric acid-reactive substances (TBA-RS), and the protein carbonyl content were measured. Neonatal hyperglycemic rats presented increased activities of G6PD, 6PGD, and Nox, which altogether may be responsible for the enhanced production of superoxide radical anion that was observed. The enhanced antioxidant enzyme activities (SOD, CAT, and GSHPx) that were observed in neonatal hyperglycemic rats, which may be caused by a rebound effect of oxidative stress, were not able to hinder the observed lipid peroxidation (TBA-RS) and protein damage in the brain. Consequently, these results suggest that oxidative stress could represent a mechanism that explains the harmful effects of neonatal hyperglycemia on the CNS.

  4. Enzymes oxidizing the azo dye 1-phenylazo-2-naphthol (Sudan I) and their contribution to its genotoxicity and carcinogenicity.

    Science.gov (United States)

    Stiborova, Marie; Schmeiser, Heinz H; Frei, Eva; Hodek, Petr; Martinek, Vaclav

    2014-01-01

    Sudan I [1-(phenylazo)-2-naphthol, C.I. Solvent Yellow 14] is an industrial dye, which was found as a contaminant in numerous foods in several European countries. Because Sudan I has been assigned by the IARC as a Category 3 carcinogen, the European Union decreed that it cannot be utilized as food colorant in any European country. Sudan I induces the malignancies in liver and urinary bladder of rats and mice. This carcinogen has also been found to be a potent mutagen, contact allergen and sensitizer, and exhibits clastogenic properties. The oxidation of Sudan I increases its toxic effects and leads to covalent adducts in DNA. Identification of enzymatic systems that contribute to Sudan I oxidative metabolism to reactive intermediates generating such covalent DNA adducts on the one hand, and to the detoxification of this carcinogen on the other, is necessary to evaluate susceptibility to this toxicant. This review summarizes the identification of such enzymes and the molecular mechanisms of oxidation reactions elucidated to date. Human and animal cytochrome P450 (CYP) and peroxidases are capable of oxidizing Sudan I. Of the CYP enzymes, CYP1A1 is most important both in Sudan I detoxification and its bio-activation. Ring-hydroxylated metabolites and a dimer of this carcinogen were found as detoxification products of Sudan I generated with CYPs and peroxidases, respectively. Oxidative bio-activation of this azo dye catalyzed by CYPs and peroxidases leads to generation of proximate genotoxic metabolites (the CYP-catalyzed formation of the benzenediazonium cation and the peroxidase-mediated generation of one-electron oxidation products), which covalently modify DNA both in vitro and in vivo. The predominant DNA adduct generated with the benzenediazonium cation was characterized to be 8-(phenylazo)guanine. The Sudan I radical species mediated by peroxidases reacts with the -NH2 group in (deoxy)guanosine, generating the 4-[(deoxy)guanosin-N(2)-yl]Sudan I product. Sudan I

  5. Oxidative stress and redox state-regulating enzymes have prognostic relevance in diffuse large B-cell lymphoma

    Directory of Open Access Journals (Sweden)

    Peroja Pekka

    2012-03-01

    Full Text Available Abstract Background Oxidative stress and redox-regulating enzymes may have roles both in lymphomagenesis and resistance to lymphoma therapy. Previous studies from the pre-rituximab era suggest that antioxidant enzyme expression is related to prognosis in diffuse large B-cell lymphoma (DLBCL, although these results cannot be extrapolated to patient populations undergoing modern treatment modalities. In this study we assessed expression of the oxidative stress markers 8-hydroxydeoxyguanosine (8-OHdG and nitrotyrosine and the antioxidant enzymes thioredoxin (Trx, manganese superoxide dismutase (MnSOD and glutamate-cysteine ligase (GCL via immunohistochemistry in 106 patients with DLBCL. All patients were treated with CHOP-like therapy combined with rituximab. Immunostaining results were correlated with progression-free survival, disease-specific survival and traditional prognostic factors of DLBCL. Results Strong 8-OHdG immunostaining intensity was associated with extranodal involvement (p = 0.00002, a high International Prognostic Index (p = 0.002 and strong Trx (p = 0.011 and GCL (p = 0.0003 expression. Strong Trx staining intensity was associated with poor progression-free survival (p = 0.046 and poor disease-specific survival (p = 0.015. Strong GCL immunostaining intensity predicted poor progression-free survival (p = 0.049. Patients with either strong Trx or strong nitrotyrosine expression showed significantly poorer progression-free survival (p = 0.003 and disease-specific survival (p = 0.031 compared with the other patients. Conclusions The redox state-regulating enzymes GCL and Trx are promising markers in the evaluation of DLBCL prognosis in the era of modern immunochemotherapy.

  6. Inducible nitric oxide synthase (NOS2) expressed in septic patients is nitrated on selected tyrosine residues: implications for enzymic activity.

    Science.gov (United States)

    Lanone, Sophie; Manivet, Philippe; Callebert, Jacques; Launay, Jean-Marie; Payen, Didier; Aubier, Michel; Boczkowski, Jorge; Mebazaa, Alexandre

    2002-01-01

    Tyrosine nitration is a post-translational protein modification with potentially significant biological implications. In the present study we demonstrate, for the first time, that tyrosine residues of human inducible nitric oxide synthase (NOS2) can be nitrated by peroxynitrite in vitro, leading to a decreased activity. Moreover, we show that NOS2 expressed in a skeletal muscle from septic patients is nitrated on selective tyrosine residues belonging to a canonic sequence. This phenomenon could be an endogenous mechanism of in vivo modulation of NOS2 enzymic activity. PMID:12097137

  7. Interaction of vitamin E and exercise training on oxidative stress and antioxidant enzyme activities in rat skeletal muscles.

    Science.gov (United States)

    Chang, Chen-Kang; Huang, Hui-Yu; Tseng, Hung-Fu; Hsuuw, Yan-Der; Tso, Tim K

    2007-01-01

    It has been shown that free radicals are increased during intensive exercise. We hypothesized that vitamin E (vit E) deficiency, which will increase oxidative stress, would augment the training-induced adaptation of antioxidant enzymes. This study investigated the interaction effect of vit E and exercise training on oxidative stress markers and activities of antioxidant enzymes in red quadriceps and white gastrocnemius of rats in a 2x2 design. Thirty-two male rats were divided into trained vit E-adequate, trained vit E-deficient, untrained vit E-adequate, and untrained vit E-deficient groups. The two trained groups swam 6 h/day, 6 days/week for 8 weeks. The two vit E-deficient groups consumed vit E-free diet for 8 weeks. Vitamin E-training interaction effect was significant on thiobarbituric acid reactive substances (TBARSs), glutathione peroxidase (GPX), and superoxide dismutase (SOD) in both muscles. The trained vit E-deficient group showed the highest TBARS and GPX activity and the lowest SOD activity in both muscles. A significant vit E effect on glutathione reductase and catalase was present in both muscles. Glutathione reductase and catalase activities were significantly lower in the two vit E-adequate groups combined than in the two vit E-deficient groups combined in both muscles. This study shows that vit E status and exercise training have interactive effect on oxidative stress and GPX and SOD activities in rat skeletal muscles. Vitamin E deprivation augmented the exercise-induced elevation in GPX activity while inhibiting exercise-induced SOD activity, possibly through elevated oxidative stress. PMID:16644199

  8. Effects of gaseous hydrogen fluoride on oxidative enzymes of Pelargonium zonale leaves

    Energy Technology Data Exchange (ETDEWEB)

    Poovaiah, B.W.; Wiebe, H.H.

    1971-10-01

    Changes in peroxidase and cytochrome oxidase enzymes were established histochemically in hydrogen fluoride fumigated leaves of Pelargonium zonale. Highest peroxidase and cytochrome oxidase activities were localized near the injured areas of fumigated leaves, and the greatest increase was observed in the phloem region.

  9. Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.

    Directory of Open Access Journals (Sweden)

    Young-Moo Choo

    Full Text Available Antennae-specific odorant-degrading enzymes (ODEs are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs. Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW, Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.

  10. Temperature stress, anti-oxidative enzyme activity and virus acquisition in Bemisia tabaci (Hemiptera: Aleyrodidae)

    Science.gov (United States)

    In most eukaryotic systems, antioxidants provide protection when cells are exposed to stressful environmental conditions. Antioxidants, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase, function in a stepwise series with SOD initially preventing oxidative damage by conve...

  11. Protective role of Cys-178 against the inactivation and oligomerization of human insulin-degrading enzyme by oxidation and nitrosylation.

    Science.gov (United States)

    Ralat, Luis A; Ren, Min; Schilling, Alexander B; Tang, Wei-Jen

    2009-12-01

    Insulin-degrading enzyme (IDE), a 110-kDa metalloendopeptidase, hydrolyzes several physiologically relevant peptides, including insulin and amyloid-beta (Abeta). Human IDE has 13 cysteines and is inhibited by hydrogen peroxide and S-nitrosoglutathione (GSNO), donors of reactive oxygen and nitrogen species, respectively. Here, we report that the oxidative burst of BV-2 microglial cells leads to oxidation or nitrosylation of secreted IDE, leading to the reduced activity. Hydrogen peroxide and GSNO treatment of IDE reduces the V(max) for Abeta degradation, increases IDE oligomerization, and decreases IDE thermostability. Additionally, this inhibitory response of IDE is substrate-dependent, biphasic for Abeta degradation but monophasic for a shorter bradykinin-mimetic substrate. Our mutational analysis of IDE and peptide mass fingerprinting of GSNO-treated IDE using Fourier transform-ion cyclotron resonance mass spectrometer reveal a surprising interplay of Cys-178 with Cys-110 and Cys-819 for catalytic activity and with Cys-789 and Cys-966 for oligomerization. Cys-110 is near the zinc-binding catalytic center and is normally buried. The oxidation and nitrosylation of Cys-819 allow Cys-110 to be oxidized or nitrosylated, leading to complete inactivation of IDE. Cys-789 is spatially adjacent to Cys-966, and their nitrosylation and oxidation together trigger the oligomerization and inhibition of IDE. Interestingly, the Cys-178 modification buffers the inhibition caused by Cys-819 modification and prevents the oxidation or nitrosylation of Cys-110. The Cys-178 modification can also prevent the oligomerization-mediated inhibition. Thus, IDE can be intricately regulated by reactive oxygen or nitrogen species. The structure of IDE reveals the molecular basis for the long distance interactions of these cysteines and how they regulate IDE function.

  12. Protective Role of Cys-178 against the Inactivation and Oligomerization of Human Insulin-degrading Enzyme by Oxidation and Nitrosylation*

    Science.gov (United States)

    Ralat, Luis A.; Ren, Min; Schilling, Alexander B.; Tang, Wei-Jen

    2009-01-01

    Insulin-degrading enzyme (IDE), a 110-kDa metalloendopeptidase, hydrolyzes several physiologically relevant peptides, including insulin and amyloid-β (Aβ). Human IDE has 13 cysteines and is inhibited by hydrogen peroxide and S-nitrosoglutathione (GSNO), donors of reactive oxygen and nitrogen species, respectively. Here, we report that the oxidative burst of BV-2 microglial cells leads to oxidation or nitrosylation of secreted IDE, leading to the reduced activity. Hydrogen peroxide and GSNO treatment of IDE reduces the Vmax for Aβ degradation, increases IDE oligomerization, and decreases IDE thermostability. Additionally, this inhibitory response of IDE is substrate-dependent, biphasic for Aβ degradation but monophasic for a shorter bradykinin-mimetic substrate. Our mutational analysis of IDE and peptide mass fingerprinting of GSNO-treated IDE using Fourier transform-ion cyclotron resonance mass spectrometer reveal a surprising interplay of Cys-178 with Cys-110 and Cys-819 for catalytic activity and with Cys-789 and Cys-966 for oligomerization. Cys-110 is near the zinc-binding catalytic center and is normally buried. The oxidation and nitrosylation of Cys-819 allow Cys-110 to be oxidized or nitrosylated, leading to complete inactivation of IDE. Cys-789 is spatially adjacent to Cys-966, and their nitrosylation and oxidation together trigger the oligomerization and inhibition of IDE. Interestingly, the Cys-178 modification buffers the inhibition caused by Cys-819 modification and prevents the oxidation or nitrosylation of Cys-110. The Cys-178 modification can also prevent the oligomerization-mediated inhibition. Thus, IDE can be intricately regulated by reactive oxygen or nitrogen species. The structure of IDE reveals the molecular basis for the long distance interactions of these cysteines and how they regulate IDE function. PMID:19808678

  13. Metal Oxide Nanosensors Using Polymeric Membranes, Enzymes and Antibody Receptors as Ion and Molecular Recognition Elements

    Directory of Open Access Journals (Sweden)

    Magnus Willander

    2014-05-01

    Full Text Available The concept of recognition and biofunctionality has attracted increasing interest in the fields of chemistry and material sciences. Advances in the field of nanotechnology for the synthesis of desired metal oxide nanostructures have provided a solid platform for the integration of nanoelectronic devices. These nanoelectronics-based devices have the ability to recognize molecular species of living organisms, and they have created the possibility for advanced chemical sensing functionalities with low limits of detection in the nanomolar range. In this review, various metal oxides, such as ZnO-, CuO-, and NiO-based nanosensors, are described using different methods (receptors of functionalization for molecular and ion recognition. These functionalized metal oxide surfaces with a specific receptor involve either a complex formation between the receptor and the analyte or an electrostatic interaction during the chemical sensing of analytes. Metal oxide nanostructures are considered revolutionary nanomaterials that have a specific surface for the immobilization of biomolecules with much needed orientation, good conformation and enhanced biological activity which further improve the sensing properties of nanosensors. Metal oxide nanostructures are associated with certain unique optical, electrical and molecular characteristics in addition to unique functionalities and surface charge features which shows attractive platforms for interfacing biorecognition elements with effective transducing properties for signal amplification. There is a great opportunity in the near future for metal oxide nanostructure-based miniaturization and the development of engineering sensor devices.

  14. Oxidised low density lipoprotein causes human macrophage cell death through oxidant generation and inhibition of key catabolic enzymes.

    Science.gov (United States)

    Katouah, Hanadi; Chen, Alpha; Othman, Izani; Gieseg, Steven P

    2015-10-01

    Oxidised low density lipoprotein (oxLDL) is thought to be a significant contributor to the death of macrophage cells observed in advanced atherosclerotic plaques. Using human-derived U937 cells we have examined the effect of cytotoxic oxLDL on oxidative stress and cellular catabolism. Within 3h of the addition of oxLDL, there was a rapid, concentration dependent rise in cellular reactive oxygen species followed by the loss of cellular GSH, and the enzyme activity of both glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and aconitase. The loss of these catabolic enzymes was accompanied by the loss of cellular ATP and lower lactate generation. Addition of the macrophage antioxidant 7,8-dihydroneopterin inhibited the ROS generation, glutathione loss and catabolic inactivation. NOX was shown to be activated by oxLDL addition while apocynin inhibited the loss of GSH and cell viability. The data suggests that oxLDL triggers an excess of ROS production through NOX activation, and catabolic failure through thiol oxidation resulting in cell death. PMID:26255116

  15. Organization of the Escherichia coli aerobic enzyme complexes of oxidative phosphorylation in dynamic domains within the cytoplasmic membrane.

    Science.gov (United States)

    Erhardt, Heiko; Dempwolff, Felix; Pfreundschuh, Moritz; Riehle, Marc; Schäfer, Caspar; Pohl, Thomas; Graumann, Peter; Friedrich, Thorsten

    2014-06-01

    The Escherichia coli cytoplasmic membrane contains the enzyme complexes of oxidative phosphorylation (OXPHOS). Not much is known about their supramolecular organization and their dynamics within the membrane in this model organism. In mitochondria and other bacteria, it was demonstrated by nondenaturing electrophoretic methods and electron microscopy that the OXPHOS complexes are organized in so-called supercomplexes, stable assemblies with a defined number of the individual enzyme complexes. To investigate the organization of the E. coli enzyme complexes of aerobic OXPHOS in vivo, we established fluorescent protein fusions of the NADH:ubiquinone oxidoreductase, the succinate:ubiquinone oxidoreductase, the cytochrome bd-I, and the cytochrome bo3 terminal oxidases, and the FoF1 ATP-synthase. The fusions were integrated in the chromosome to prevent artifacts caused by protein overproduction. Biochemical analysis revealed that all modified complexes were fully assembled, active, and stable. The distribution of the OXPHOS complexes in living cells was determined using total internal reflection fluorescence microscopy. The dynamics within the membrane were detected by fluorescence recovery after photobleaching. All aerobic OXPHOS complexes showed an uneven distribution in large mobile patches within the E. coli cytoplasmic membrane. It is discussed whether the individual OXPHOS complexes are organized as clustered individual complexes, here called "segrazones."

  16. Lytic polysaccharide monooxygenases and other oxidative enzymes are abundantly secreted by Aspergillus nidulans grown on different starches

    DEFF Research Database (Denmark)

    Nekiunaite, Laura; Arntzen, Magnus Ø.; Svensson, Birte;

    2016-01-01

    by amylolytic activity measurements. Nearly half of the 312 proteins in the secretomes were carbohydrate-active enzymes (CAZymes), mostly glycoside hydrolases (GHs) and oxidative auxiliary activities (AAs). The abundance of the GH13 α-amylase (AmyB) decreased with time, as opposed to other starch......-degrading enzymes, e.g., the GH13 AmyF, GH15 glucoamylases (GlaA and GlaB), and the GH31 α-glucosidase (AgdE). Two AA13 LPMOs displayed similar secretion patterns as amylolytic hydrolases and were among the most abundant CAZymes. The starch-active AnLPMO13A that possesses a CBM20 carbohydrate-binding module...... dominated the starch-binding secretome fraction. A striking observation is the co-secretion of several redox-active enzymes with the starch-active AA13 LPMOs and GHs, some at high abundance. Notably nine AA9 LPMOs, six AA3 sub-family 2 (AA_2) oxidoreductases, and ten AA7 glyco-oligosaccharide oxidases were...

  17. Crystal Structure of Reduced and of Oxidized Peroxiredoxin IV Enzyme Reveals a Stable Oxidized Decamer and a Non-disulfide-bonded Intermediate in the Catalytic Cycle*

    Science.gov (United States)

    Cao, Zhenbo; Tavender, Timothy J.; Roszak, Aleksander W.; Cogdell, Richard J.; Bulleid, Neil J.

    2011-01-01

    Peroxiredoxin IV (PrxIV) is an endoplasmic reticulum-localized enzyme that metabolizes the hydrogen peroxide produced by endoplasmic reticulum oxidase 1 (Ero1). It has been shown to play a role in de novo disulfide formation, oxidizing members of the protein disulfide isomerase family of enzymes, and is a member of the typical 2-Cys peroxiredoxin family. We have determined the crystal structure of both reduced and disulfide-bonded, as well as a resolving cysteine mutant of human PrxIV. We show that PrxIV has a similar structure to other typical 2-Cys peroxiredoxins and undergoes a conformational change from a fully folded to a locally unfolded form following the formation of a disulfide between the peroxidatic and resolving cysteine residues. Unlike other mammalian typical 2-Cys peroxiredoxins, we show that human PrxIV forms a stable decameric structure even in its disulfide-bonded state. In addition, the structure of a resolving cysteine mutant reveals an intermediate in the reaction cycle that adopts the locally unfolded conformation. Interestingly the peroxidatic cysteine in the crystal structure is sulfenylated rather than sulfinylated or sulfonylated. In addition, the peroxidatic cysteine in the resolving cysteine mutant is resistant to hyper-oxidation following incubation with high concentrations of hydrogen peroxide. These results highlight some unique properties of PrxIV and suggest that the equilibrium between the fully folded and locally unfolded forms favors the locally unfolded conformation upon sulfenylation of the peroxidatic cysteine residue. PMID:21994946

  18. Expression profile of oxidative and antioxidative stress enzymes based on ESTs approach of citrus

    OpenAIRE

    Luis Antonio Peroni; Renato Rodrigues Ferreira; Antonio Figueira; Marcos Antonio Machado; Dagmar Ruth Stach-Machado

    2007-01-01

    Plants not only evolve but also reduce oxygen in photosynthesis. An inevitable consequence of this normal process is the production of reactive oxygen species (ROS). Plants are adequately protected by the presence of multiple antioxidative enzymes in the cytosol and also in the different cell organelles such as chloroplasts, mitochondria, and peroxisomes. Traditionally, ROS were considered to be only a toxic byproduct of aerobic metabolism. However, recently it has become apparent that plants...

  19. Enzyme catalyzed oxidative gelation of sugar beet pectin: Kinetics and rheology

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz; Chronakis, Ioannis S.; Meyer, Anne S.

    2012-01-01

    effects and interactions between different factors on the gelation rates and gel properties were examined in response surface designs in which enzyme dosage (0.125–2.0 U mL−1 for HRP; 0.125–10 U mL−1 for laccase), substrate concentration (1.0–4.0%), temperature (25–55 °C), pH (3.5–5.5), and H2O2 (0...

  20. Immobilization of Leachable Toxic Soil Pollutants by Using Oxidative Enzymes

    OpenAIRE

    Shannon, Michael J. R.; Bartha, Richard

    1988-01-01

    Screening of leachable toxic chemicals in a horseradish peroxidase-H2O2 immobilization system established that immobilization was promising for most phenolic pollutants but not for benzoic acid, 2,6-dinitrocresol, or dibutyl phthalate. The treatment did not mobilize inherently nonmobile pollutants such as anilines and benzo[a]pyrene. In a separate study, an extracellular laccase in the culture filtrate of Geotrichum candidum was selected from five fungal enzymes evaluated as a cost-effective ...

  1. ANTI-OXIDANT AND ENZYME-INHIBITORY POTENTIAL OF MARINE STREPTOMYCES

    Directory of Open Access Journals (Sweden)

    K. Suthindhiran

    2013-01-01

    Full Text Available Marine actinomycetes are potential source for the discovery of novel compounds and enzymes. Though extensive research on marine actinomycetes is underway globally, the actinomycetes research from Indian marine ecosystem is unexplored and understudied. Hence, the present research is focussed on the screening of bioactive compounds from marine actinomycetes isolated from Indian coastal region. This study is designed to determine the antioxidant and enzyme inhibitory potential of Streptomyces sp. VITMSS05 strain, isolated from Marakkanam, southern coast of India. An actinomycetes strain designated as VITMSS05 was isolated. This strain was cultivated in Starch Caesin Agar medium (SCA supplemented with sea water. The cultural, morphological and molecular characterization was determined for the isolate. The crude extract of the isolate was extracted with ethyl acetate. Antioxidant activity of the crude extract was determined by DPPH radical scavenging assay. Alpha amylase and alpha glucosidase inhibitory potential of the extract was determined. Based on the phenotypic and phylogenetic analysis the strain was identified as Streptomyces sp. Significant antioxidant activity of the extract was observed with an IC50 value of 92.49 μg mL-1. The extract shows 64.1% inhibition on α-amylase and 91.5% inhibition on α-glucosidase at 100 μg mL-1 with an IC50 value of 385.97 and 42.89 μg mL-1. From the results it is evident that the ethyl acetate extract of Streptomyces sp. VITMSS05 has potent antioxidant and enzyme inhibitory activity in vitro. The combined effect of free radical scavenging and enzyme inhibition makes it a potent anti diabetic drug.

  2. Selenium ameliorates arsenic induced oxidative stress through modulation of antioxidant enzymes and thiols in rice (Oryza sativa L.).

    Science.gov (United States)

    Kumar, Amit; Singh, Rana Pratap; Singh, Pradyumna Kumar; Awasthi, Surabhi; Chakrabarty, Debasis; Trivedi, Prabodh Kumar; Tripathi, Rudra Deo

    2014-09-01

    Arsenic (As) contamination of rice is a major problem for South-East Asia. In the present study, the effect of selenium (Se) on rice (Oryza sativa L.) plants exposed to As was studied in hydroponic culture. Arsenic accumulation, plant growth, thiolic ligands and antioxidative enzyme activities were assayed after single (As and Se) and simultaneous supplementations (As + Se). The results indicated that the presence of Se (25 µM) decreased As accumulation by threefold in roots and twofold in shoots as compared to single As (25 µM) exposed plants. Arsenic induced oxidative stress in roots and shoots was significantly ameliorated by Se supplementation. The observed positive response was found associated with the increased activities of ascorbate peroxidase (APX; EC 1.11.1.11), catalase (CAT; EC 1.11.1.6) and glutathione peroxidase (GPx; EC 1.11.1.9) and induced levels of non-protein thiols (NPTs), glutathione (GSH) and phytochelatins (PCs) in As + Se exposed plants as compared to single As treatment. Selenium supplementation modulated the thiol metabolism enzymes viz., γ-glutamylcysteine synthetase (γ-ECS; EC 6.3.2.2), glutathione-S-transferase (GST; EC 2.5.1.18) and phytochelatin synthase (PCS; EC 2.3.2.15). Gene expression analysis of several metalloid responsive genes (LOX, SOD and MATE) showed upregulation during As stress, however, significant downregulation during As + Se exposure as compared to single As treatment. Gene expressions of enzymes of antioxidant and GSH and PC biosynthetic systems, such as APX, CAT, GPx, γ-ECS and PCS were found to be significantly positively correlated with their enzyme activities. The findings suggested that Se supplementation could be an effective strategy to reduce As accumulation and toxicity in rice plants.

  3. Health-Beneficial Phenolic Aldehyde in Antigonon leptopus Tea

    Directory of Open Access Journals (Sweden)

    Vanisree Mulabagal

    2011-01-01

    Full Text Available Tea prepared from the aerial parts of Antigonon leptopus is used as a remedy for cold and pain relief in many countries. In this study, A. leptopus tea, prepared from the dried aerial parts, was evaluated for lipid peroxidation (LPO and cyclooxygenase (COX-1 and COX-2 enzyme inhibitory activities. The tea as a dried extract inhibited LPO, COX-1 and COX-2 enzymes by 78%, 38% and 89%, respectively, at 100 g/mL. Bioassay-guided fractionation of the extract yielded a selective COX-2 enzyme inhibitory phenolic aldehyde, 2,3,4-trihydroxy benzaldehyde. Also, it showed LPO inhibitory activity by 68.3% at 6.25 g/mL. Therefore, we have studied other hydroxy benzaldehydes and their methoxy analogs for LPO, COX-1 and COX-2 enzymes inhibitory activities and found that compound 1 gave the highest COX-2 enzyme inhibitory activity as indicated by a 50% inhibitory concentration (IC50 at 9.7 g/mL. The analogs showed only marginal LPO activity at 6.25 g/mL. The hydroxy analogs 6, 7 and 9 showed 55%, 61% and 43% of COX-2 inhibition at 100 g/mL. However, hydroxy benzaldehydes 3 and 12 showed selective COX-1 inhibition while compounds 4 and 10 gave little or no COX-2 enzyme inhibition at 100 g/mL. At the same concentration, compounds 14, 21 and 22 inhibited COX-1 by 83, 85 and 70%, respectively. Similarly, compounds 18, 19 and 23 inhibited COX-2 by 68%, 72% and 70%, at 100 g/mL. This is the first report on the isolation of compound 1 from A. leptopus tea with selective COX-2 enzyme and LPO inhibitory activities.

  4. Plasma Homocysteine Is Associated with Increased Oxidative Stress and Antioxidant Enzyme Activity in Welders

    Directory of Open Access Journals (Sweden)

    Hung-Hsin Liu

    2013-01-01

    Full Text Available The purpose of this study was to examine the association of vitamin B6 status and plasma homocysteine with oxidative stress and antioxidant capacities in welders. Workers were divided into either the welding exposure group (n=57 or the nonexposure controls (n=42 based on whether they were employed as welders. There were no significant differences in vitamin B6 status and plasma homocysteine concentration between the welding exposure group and the nonexposure controls. The welding exposure group had significantly higher levels of oxidized low-density lipoprotein cholesterol and lower erythrocyte glutathione concentration and superoxide dismutase (SOD activities when compared to nonexposure controls. Plasma pyridoxal 5′-phosphate concentration did not correlate with oxidative stress indicators or antioxidant capacities in either group. However, plasma homocysteine significantly correlated with total antioxidant capacity (TAC (partial rs=-0.34, P<0.05 and erythrocyte SOD activities (partial rs=0.29, P<0.05 after adjusting for potential confounders in the welding exposure group. In the welding exposure group, adequate vitamin B6 status was not associated with oxidative stress or antioxidant capacities. However, elevated plasma homocysteine seemed to be a major contributing factor to antioxidant capacities (TAC and erythrocyte SOD activities in welders.

  5. Effect of curcumin on LDL oxidation in vitro, and lipid peroxidation and antioxidant enzymes in cholesterol fed rabbits.

    Science.gov (United States)

    Mahfouz, Mohamedain M; Zhou, Qi; Kummerow, Fred A

    2011-11-01

    In this study we examined the antioxidant effect of curcumin on lipid oxidation in vitro and in vivo. In vitro, curcumin at 5 microgM concentration completely prevented low-density lipoprotein (LDL) oxidation by CuS0(4), indicating that curcumin is an effective antioxidant in vitro. In vivo, feeding a pure cholesterol (PC)-rich diet to rabbits significantly increased the plasma and liver lipids as well as thiobarbituric acid reactive substances (TBARS) levels. Addition of curcumin to the PC diet did not show any effect on either plasma lipid and TBARS or liver lipids. Liver TBARS tended to decrease but that decrease was not significant. Erythrocyte glutathione peroxidase (GSH-Px) activity was significantly decreased while catalase activity was significantly increased in rabbits fed a PC diet. The addition of curcumin to a PC diet did not show any significant effect on erythrocyte enzyme activities compared to the rabbits fed a PC diet. The liver GSH-Px and catalase activities were significantly decreased in rabbits fed a PC diet, but the addition of curcumin to the PC diet enhanced the liver GSH-Px activity, which became nonsignificantly different from the control group. These results were discussed considering that curcumin may not be well absorbed and it did not reach a level high enough in vivo to overcome the severe hypercholesterolemia and oxidative stress produced by the PC-rich diet.

  6. Purification, characterization, and properties of an aryl aldehyde oxidoreductase from Nocardia sp. strain NRRL 5646.

    OpenAIRE

    Li, T.; Rosazza, J P

    1997-01-01

    An aryl aldehyde oxidoreductase from Nocardia sp. strain NRRL 5646 was purified 196-fold by a combination of Mono-Q, Reactive Green 19 agarose affinity, and hydroxyapatite chromatographies. The purified enzyme runs as a single band of 140 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular mass was estimated to be 163 +/- 3.8 kDa by gel filtration, indicating that this enzyme is a monomeric protein. The binding of the enzyme to Reactive Green 19 agarose was Mg2+ de...

  7. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean.

    Science.gov (United States)

    Pimentel, Marta S; Faleiro, Filipa; Diniz, Mário; Machado, Jorge; Pousão-Ferreira, Pedro; Peck, Myron A; Pörtner, Hans O; Rosa, Rui

    2015-01-01

    Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm) significantly decreased metabolic rates (up to 27.4 %) of flatfish larvae, Solea senegalensis, at both present (18 °C) and warmer temperatures (+4 °C). Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT) and glutathione S-transferase (GST), mainly in post-metamorphic larvae (30 dph). The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph) seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase) and intestinal enzymes (up to 36.1 % for alkaline phosphatase) in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels) were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems. PMID:26221723

  8. Oxidative Stress and Digestive Enzyme Activity of Flatfish Larvae in a Changing Ocean.

    Directory of Open Access Journals (Sweden)

    Marta S Pimentel

    Full Text Available Until now, it is not known how the antioxidant and digestive enzymatic machinery of fish early life stages will change with the combined effects of future ocean acidification and warming. Here we show that high pCO2 (~1600 μatm significantly decreased metabolic rates (up to 27.4 % of flatfish larvae, Solea senegalensis, at both present (18 °C and warmer temperatures (+4 °C. Moreover, both warming and hypercapnia increased the heat shock response and the activity of antioxidant enzymes, namely catalase (CAT and glutathione S-transferase (GST, mainly in post-metamorphic larvae (30 dph. The lack of changes in the activity of CAT and GST of pre-metamorphic larvae (10 dph seems to indicate that earlier stages lack a fully-developed antioxidant defense system. Nevertheless, the heat shock and antioxidant responses of post-metamorphic larvae were not enough to avoid the peroxidative damage, which was greatly increased under future environmental conditions. Digestive enzymatic activity of S. senegalensis larvae was also affected by future predictions. Hypercapnic conditions led to a decrease in the activity of digestive enzymes, both pancreatic (up to 26.1 % for trypsin and 74.5 % for amylase and intestinal enzymes (up to 36.1 % for alkaline phosphatase in post-metamorphic larvae. Moreover, the impact of ocean acidification and warming on some of these physiological and biochemical variables (namely, lower OCR and higher HSP and MDA levels were translated into larvae performance, being significantly correlated with decreased larval growth and survival or increased incidence of skeletal deformities. The increased vulnerability of flatfish early life stages under future ocean conditions is expected to potentially determine recruitment and population dynamics in marine ecosystems.

  9. Biomimetic oxidation studies. 9. Mechanistic aspects of the oxidation of alcohols with functional,active site methane monooxygenase enzyme models in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Rabion, A. [Lawrence Berkeley National Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)]|[Groupement de Recherche de Lacq, Artix (France); Chen, S.; Wang, J.; Buchanan, R.M. [Univ. of Louisville, KY (United States); Seris, J.L. [Groupement de recherche de Lacq, Artix (France); Fish, R.H. [Lawrence Berkeley National Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

    1995-12-13

    The syntheses of biomimetic complexes that mimic the major structural features of the hydroxylase component of methane monooxygenase enzyme (MMO) and, more importantly, that provide similar alkane functionalization activity, in the presence of an oxidant, have been of great interest to the discipline of bioinorganic chemistry. In this communication, we will demonstrate the feasibility of conducting biomimetic oxidation studies in H{sub 2}O with soluble substrates, i.e., alcohols (cyclohexanol, benzyl alcohol), using H{sub 2}O-stable MMO mimics at pH 4.2, and the oxidant, tert-butyl hydroperoxide (TBHP). Both the Mitusunobu procedure and the mesylate displacement reaction proceeded with complete inversion of the stereo-center and provided optically pure penultimate intermediate (>99.9% ee). The synthesis was completed by reduction of the nitro group under standard conditions to deliver LY300164 in 87%. In summary, we have developed an efficient and environmentally benign synthesis of the 5H-2,3-benzodiazepine LY300164 that provides the optically pure compound in 51% overall yield. Intramolecular hydrazone alkylation led to a remarkably facile and selective formation of the benzodiazepine. Furthermore, the application of resins to whole-cell-based biotransformations should find general utility for similar reactions that are complicated by component inhibition and product isolation. 11 refs., 1 fig.

  10. Catalytic production of methyl acrylates by gold-mediated cross coupling of unsaturated aldehydes with methanol

    Science.gov (United States)

    Karakalos, Stavros; Zugic, Branko; Stowers, Kara J.; Biener, Monika M.; Biener, Juergen; Friend, Cynthia M.; Madix, Robert J.

    2016-10-01

    Modern methods of esterification, one of the most important reactions in organic synthesis, are reaching their limits, as far as waste and expense are concerned. Novel chemical approaches to ester formation are therefore of importance. Here we report a simple procedure free of caustic reagents or byproducts for the facile direct oxidative methyl esterification of aldehydes over nanoporous Au catalysts. Complementary model studies on single crystal gold surfaces establish the fundamental reactions involved. We find that methanol more readily reacts with adsorbed active oxygen than do the aldehydes, but that once the aldehydes do react, they form strongly-bound acrylates that block reactive sites and decrease the yields of acrylic esters under steady flow conditions at 420 K. Significant improvements in yield can be achieved by operating at higher temperatures, which render the site-blocking acrylates unstable.

  11. Isolation of cDNA clones encoding an enzyme from bovine cells that repairs oxidative DNA damage in vitro: homology with bacterial repair enzymes.

    OpenAIRE

    Robson, C.N.; Milne, A M; Pappin, D J; Hickson, I. D.

    1991-01-01

    Ionizing radiation and radiomimetic compounds, such as hydrogen peroxide and bleomycin, generate DNA strand breaks with fragmented deoxyribose 3' termini via the formation of oxygen-derived free radicals. These fragmented sugars require removal by enzymes with 3' phosphodiesterase activity before DNA synthesis can proceed. An enzyme that reactivates bleomycin-damaged DNA to a substrate for Klenow polymerase has been purified from calf thymus. The enzyme, which has a Mr of 38,000 on SDS-PAGE, ...

  12. Effect of dose and source of supplemental zinc on immune response and oxidative enzymes in lambs.

    Science.gov (United States)

    Nagalakshmi, D; Dhanalakshmi, K; Himabindu, D

    2009-10-01

    An experiment of 150 days was conducted on 42 male Nellore lambs (28.3 +/- 0.64 kg) to determine the effect of zinc (Zn) supplementation (0,15, 30 and 45 ppm) in diet from inorganic (ZnSO(4)) and organic (Zn proteinate) sources on immune response and antioxidant enzyme activities by allotting them randomly to 7 groups in completely randomized design. The basal diet (BD) contained 29.28 ppm Zn. The humoral immune response assessed at 75 d against B. abortus was higher (Peffect on titres against chicken RBC antigen. The cell mediated immune response assessed as delayed type hypersensitivity (DTH) response against phytohaemagglutinin-P and in vitro lymphocyte proliferative response against concanavalin A at 150 d was higher (Peffect on immune response. The DTH response and antibody titres against B.abortus were higher (Pconcentration and alkaline phosphatase (ALP) activity (75 d of experiment) was higher in Zn supplemented lambs. The ALP activity increased (P enzyme activities and immune response compared to ZnSO(4).

  13. Nitrite promotes protein carbonylation and Strecker aldehyde formation in experimental fermented sausages: are both events connected?

    Science.gov (United States)

    Villaverde, A; Ventanas, J; Estévez, M

    2014-12-01

    The role played by curing agents (nitrite, ascorbate) on protein oxidation and Strecker aldehyde formation is studied. To fulfill this objective, increasing concentrations of nitrite (0, 75 and 150ppm) and ascorbate (0, 250 and 500ppm) were added to sausages subjected to a 54day drying process. The concurrence of intense proteolysis, protein carbonylation and formation of Strecker aldehydes during processing of sausages suggests that α-aminoadipic semialdehyde (AAS) and γ-glutamic semialdehyde (GGS) may be implicated in the formation of Strecker aldehydes. The fact that nitrite (150ppm, ingoing amount) significantly promoted the formation of protein carbonyls at early stages of processing and the subsequent formation of Strecker aldehydes provides strength to this hypothesis. Ascorbate (125 and 250ppm) controlled the overall extent of protein carbonylation in sausages without declining the formation of Strecker aldehydes. These results may contribute to understanding the chemistry fundamentals of the positive influence of nitrite on the flavor and overall acceptability of cured muscle foods.

  14. Impaired metabolism of senescent muscle satellite cells is associated with oxidative modifications of glycolytic enzymes

    DEFF Research Database (Denmark)

    Baraibar, Martin; Hyzewicz, Janek; Rogowska-Wrzesinska, Adelina;

    2014-01-01

    Accumulation of damaged macromolecules, including irreversibly oxidized proteins, is a hallmark of cellular and organismal ageing. Failure of protein homesotasis is a major contributor to the age-related accumulation of damaged proteins. In skeletal muscle, tissue maintenance and regeneration....... Inactivation of the proteasome in aged cells appeared as a key contributor to the accumulation of such damaged proteins. Untargeted metabolomic profiling and functional analyses indicated glucose metabolism impairment in senescent cells, although mitochondrial respiration remained unaffected. A metabolic shift...... lipids for energy production. Such changes reflect alterations in membrane composition and dysregulation of sphingolipids signaling during senescence. This study establishes a new concept connecting oxidative protein modifications with the altered cellular metabolism associated with the senescent...

  15. Pancreatic carboxyl ester lipase: a circulating enzyme that modifies normal and oxidized lipoproteins in vitro.

    OpenAIRE

    Shamir, R; Johnson, W. J.; Morlock-Fitzpatrick, K; Zolfaghari, R; Li, L; mas, e; Lombardo, D.; Morel, D W; Fisher, E A

    1996-01-01

    Pancreatic carboxyl ester lipase (CEL) hydrolyzes cholesteryl esters (CE), triglycerides (TG), and lysophospholipids, with CE and TG hydrolysis stimulated by cholate. Originally thought to be confined to the gastrointestinal system, CEL has been reported in the plasma of humans and other mammals, implying its potential in vivo to modify lipids associated with LDL, HDL (CE, TG), and oxidized LDL (lysophosphatidylcholine, lysoPC). We measured the concentration of CEL in human plasma as 1.2+/-0....

  16. Synthesis of Discodermolide Subunits by S(E)2' Addition of Nonracemic Allenylstannanes to Aldehydes.

    Science.gov (United States)

    Marshall, James A.; Lu, Zhi-Hui; Johns, Brian A.

    1998-02-01

    Three subunits, 15, 29, and 34, of the immunosuppressant discodermolide were prepared starting from (S)-3-[(tert-butyldimethylsilyl)oxy]-2-methylpropanal ((S)-1) and the enantioenriched allenylstannanes (P)-2a, (P)-2b, and (P)-31. The route to 15 involved BF(3)-promoted addition of stannane (P)-2a to aldehyde (S)-1 which afforded the syn,syn-homopropargylic alcohol adduct 3 in 97% yield. The derived p-methoxybenzylidene acetal 5 was treated with Red-Al to effect cleavage of the pivalate and reduction of the double bond leading to the (E)-allylic alcohol 6. Sharpless epoxidation and subsequent addition of Me(2)CuCNLi(2) yielded the syn,syn,syn,anti stereopentad, diol 8. Protection of the secondary alcohol and oxidation of the primary gave aldehyde 12, which was treated with the alpha-bromo allylsilane 13 and CrCl(2), followed by NaH to effect elimination to the diene 15. A similar sequence was employed to prepare aldehyde 29. In this case aldehyde (S)-1 was converted to the anti,syn-homopropargylic alcohol 20 by treatment with the allenyl indium reagent formed in situ from allenylstannane (P)-2b and InBr(3). Epoxy alcohol 24, prepared from alcohol 20 by the above-described sequence, was reduced with Red-Al to afford diol 25. Protection of the secondary alcohol and oxidation of the primary completed the synthesis of 29. The anti,syn-homopropargylic alcohol 32 was obtained through addition of the allenic indium reagent, from allenylstannane (P)-31, to aldehyde (S)-1. Protection of the derived diol 33 as the p-methoxybenzylidene acetal afforded the third subunit, acetylene 34. Addition of the lithio derivative of 34 to aldehyde 29 gave alcohol 35 with the carbinyl stereochemistry needed for C7 of discodermolide as the major product.

  17. Enzyme monolayer- and bilayer-modified tin oxide electrodes for the determination of hydrogen peroxide and glucose

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuma, Tetsu; Okawa, Yusuke; Watanabe, Tadashi (Univ. of Tokyo (Japan))

    1989-11-01

    An enzyme-based amperometric biosensor for hydrogen peroxide was developed, employing a horseradish peroxidase (HRP) monolayer covalently attached to a tin oxide electrode and a dissolved electron mediator. The sensor can determine hydrogen peroxide at levels down to 10{sup {minus}8} M and can be applied to a flow system. Stability of the electrode, kinetics of the surface process, and the efficiencies of different mediators were studied. As an extension, glucose oxidase (GOx) was chemically bound to the HRP-modified electrode. A GOx/HRP bilayer-modified electrode thus obtained exhibits much better performance in glucose detection limit, sensitivity, and response speed than previously reported GOx monolayer-modified electrodes.

  18. Regulation of oxidative enzyme activity and eukaryotic elongation factor 2 in human skeletal muscle: influence of gender and exercise

    DEFF Research Database (Denmark)

    Roepstorff, Carsten; Schjerling, P.; Vistisen, Bodil;

    2005-01-01

    AIM: To investigate gender-related differences in the responses of oxidative enzymes and eukaryotic elongation factor-2 (eEF2) to exercise. METHODS: The influence of exercise (90 min, 60%VO(2peak)) on citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (HAD) activity and mRNA content......, together with eEF2 expression and phosphorylation at rest, were assessed in skeletal muscle of untrained (UT) and endurance trained (ET) females and males. RESULTS: Citrate synthase and HAD mRNA were higher in females than in males (27% and 48%, respectively, P activity did...... not differ between females and males (NS). In females only, CS activity was enhanced (P activity was 56% higher in ET than in UT volunteers (P activity were not influenced...

  19. Combined Effects of Excess Mn and Low pH on Oxidative Stress and Antioxidant Enzymes in Cucumber Roots

    Institute of Scientific and Technical Information of China (English)

    SHI Qing-hua; ZHU Zhu-jun; LI Juan; QIAN Qiong-qiu

    2006-01-01

    The effects of excess Mn on oxidative stress and antioxidant enzymes in cucumber roots under different pH (pH 4.5 and 6.5) were studied. The results indicated that lipid peroxidation was increasingly serious with the increased concentration of Mn, especially under low pH. As a result, the growth of cucumber roots and shoots was significantly inhibited. CAT was sensitive to excess Mn, and its activity significantly decreased under excess Mn and low pH, while activities of GPX, APX, DHAR and GR increased under low pH and to some extent under excess Mn, which indicated their important roles in scavenging reactive oxygen in tolerance to low pH and excess Mn of cucumber roots.

  20. Determination of linear aliphatic aldehydes in heavy metal containing waters by high-performance liquid chromatography using 2,4-dinitrophenylhydrazine derivatization.

    Science.gov (United States)

    Lin, Yi-Liang; Wang, Po-Yen; Hsieh, Ling-Ling; Ku, Kuan-Hsuan; Yeh, Yun-Tai; Wu, Chien-Hou

    2009-09-01

    A simple and sensitive method is described for the determination of picomolar amounts of C(1)-C(9) linear aliphatic aldehydes in waters containing heavy metal ions. In this method, aldehydes were first derivatized with 2,4-dinitrophenylhydrazine (DNPH) at optimized pH 1.8 for 30 min and analyzed by HPLC with UV detector at 365 nm. Factors affecting the derivatization reaction of aldehydes and DNPH were investigated. Cupric ion, an example of heavy metals, is a common oxidative reagent, which may oxidize DNPH and greatly interfere with the determination of aldehydes. EDTA was used to effectively mask the interferences by heavy metal ions. The method detection limits for direct injection of derivatized most aldehydes except formaldehyde were of the order of 7-28 nM. The detection limit can be further lowered by using off-line C(18) adsorption cartridge enrichment. The recoveries of C(1)-C(9) aldehydes were 93-115% with a relative standard deviation of 3.6-8.1% at the 0.1 microM level for aldehydes. The HPLC-DNPH method has been applied for determining aldehyde photoproducts from Cu(II)-amino acid complex systems. PMID:19643424

  1. Interaction of carbohydrates with alcohol dehydrogenase: Effect on enzyme activity.

    Science.gov (United States)

    Jadhav, Swati B; Bankar, Sandip B; Granström, Tom; Ojamo, Heikki; Singhal, Rekha S; Survase, Shrikant A

    2015-09-01

    Alcohol dehydrogenase was covalently conjugated with three different oxidized carbohydrates i.e., glucose, starch and pectin. All the carbohydrates inhibited the enzyme. The inhibition was studied with respect to the inhibition rate constant, involvement of thiol groups in the binding, and structural changes in the enzyme. The enzyme activity decreased to half of its original activity at the concentration of 2 mg/mL of pectin, 4 mg/mL of glucose and 10 mg/mL of starch within 10 min at pH 7. This study showed oxidized pectin to be a potent inhibitor of alcohol dehydrogenase followed by glucose and starch. Along with the aldehyde-amino group interaction, thiol groups were also involved in the binding between alcohol dehydrogenase and carbohydrates. The structural changes occurring on binding of alcohol dehydrogenase with oxidized carbohydrates was also confirmed by fluorescence spectrophotometry. Oxidized carbohydrates could thus be used as potential inhibitors of alcohol dehydrogenase.

  2. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 73, Revision 2 (FGE.73Rev2). Consideration of alicyclic primary alcohols, aldehydes, acids and related esters evaluated by JECFA (59th meeting) structurally related to primary saturated or unsaturated alicyclic alcohols, aldehydes, acids and esters evaluated by EFSA in FGE.12Rev3 (2012)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... for the materials of commerce have also been considered and for all 18 substances, the information is adequate....

  3. S-nitrosylation of dimethylarginine dimethylaminohydrolase regulates enzyme activity: Further interactions between nitric oxide synthase and dimethylarginine dimethylaminohydrolase

    Science.gov (United States)

    Leiper, James; Murray-Rust, Judith; McDonald, Neil; Vallance, Patrick

    2002-01-01

    The enzyme dimethylarginine dimethylaminohydrolase (DDAH) hydrolyses asymmetrically methylated arginine residues that are endogenously produced inhibitors of nitric oxide synthases (NOS). We and others have proposed that DDAH activity is a key determinant of intracellular methylarginine concentrations and that factors that regulate the activity of DDAH may modulate nitric oxide (NO) production in vivo. We recently solved the crystal structure of a bacterial DDAH and identified a Cys-His-Glu catalytic triad [Murray-Rust, J., Leiper, J. M., McAlister, M., Phelan, J., Tilley, S., Santa Maria, J., Vallance, P. & McDonald, N. (2001) Nat. Struct. Biol. 8, 679–683]. The presence of a reactive cysteine residue (Cys-249) in the active site of DDAH raised the possibility that DDAH activity might be directly regulated by S-nitrosylation of this residue by NO. In the present study, we demonstrate that recombinant DDAH is reversibly inhibited after incubation with NO donors in vitro. Similarly mammalian DDAH in cytosolic extracts is also reversibly inhibited by NO donors. In cultured endothelial cells, heterologously expressed human DDAH II was S-nitrosylated after cytokine induced expression of the inducible NOS isoforms. The implication of these findings is that under certain conditions when NO generation increases, S-nitrosylation diminishes DDAH activity and this would be expected to lead to accumulation of asymmetric dimethylarginine and inhibition of NOS. This observation may help explain why expression of iNOS often leads to inhibition of activity of constitutively expressed NOS isozymes. We also identify Cys-His-Glu as a nitrosylation motif that is conserved in a family of arginine handling enzymes. PMID:12370443

  4. Oxidative burst and the activity of defense-related enzymes in compatible and incompatible tomato-Alternaria solani interactions

    Directory of Open Access Journals (Sweden)

    Maria Isabel Balbi-Peña

    2014-10-01

    Full Text Available The production of reactive oxygen species (ROS, hypersensitive response (HR, and the activity of the enzymes guaiacol peroxidase, catalase, polyphenol oxidase, B-1,3-glucanase and chitinase, were studied in leaves of resistant [CNPH 1287 (Solanum habrochaites syn. Lycopersicon hirsutum] and susceptible [Santa Cruz Kada (S. lycopersicum syn. L. esculentum] tomato genotypes inoculated with Alternaria solani. Leaves were collected at the time of inoculation and at 4, 8, 12, 24, 48, 72, 96 and 120 hours post inoculation. Conidia germination occurred equally onto the leaf surface in both genotypes and germination tubes grew without apparent orientation. Lesion frequency was lower in CNPH 1287, and it was the consequence of a lower number of appressoria formed in that genotype. ROS were observed in low frequency in both genotypes. HR was observed in penetrated epidermal host cells also in both genotypes. It seems that ROS and HR would not contribute to the resistance of S. habrochaites to A. solani in this study. The activity of guaiacol peroxidase, polyphenol oxidase, B-1,3-glucanase and chitinase was significantly increased in the resistant genotype. These results suggest that defense-related enzymes but no oxidative burst play a role in the defense response of S. habrochaites to A. solani.

  5. Oxidative stability and antioxidant enzyme activities of dry-cured bacons as affected by the partial substitution of NaCl with KCl.

    Science.gov (United States)

    Wu, Haizhou; Yan, Wenjing; Zhuang, Hong; Huang, Mingming; Zhao, Jianying; Zhang, Jianhao

    2016-06-15

    This study investigated the influence of partial substitution of NaCl with KCl on protein and lipid oxidation as well as antioxidant enzyme activities in dry-cured bacons during processing. The partial substitution was 0% KCl (I), 40% KCl (II), and 70% KCl (III). Compared with 0% KCl (I), the substitution of 40% NaCl with KCl did not significantly influence the protein and lipid oxidation and antioxidant enzyme activities. The bacons that were treated with 70% KCl treatment (III) showed increased lipid oxidation and antioxidant enzyme GSH-Px activity, whereas samples treated with formulas I and II showed higher protein oxidation and antioxidant enzyme catalase activity. These results demonstrate that the substitution of NaCl with KCl by more than 40% may significantly affect protein and lipid oxidation and that for the substitution of NaCl in further processed meat products with other chloride salts, salt content is very important for control of protein and lipid biochemical changes in finished products. PMID:26868571

  6. Role of beta-oxidation enzymes in gamma-decalactone production by the yeast Yarrowia lipolytica.

    Science.gov (United States)

    Waché, Y; Aguedo, M; Choquet, A; Gatfield, I L; Nicaud, J M; Belin, J M

    2001-12-01

    Some microorganisms can transform methyl ricinoleate into gamma-decalactone, a valuable aroma compound, but yields of the bioconversion are low due to (i) incomplete conversion of ricinoleate (C(18)) to the C(10) precursor of gamma-decalactone, (ii) accumulation of other lactones (3-hydroxy-gamma-decalactone and 2- and 3-decen-4-olide), and (iii) gamma-decalactone reconsumption. We evaluated acyl coenzyme A (acyl-CoA) oxidase activity (encoded by the POX1 through POX5 genes) in Yarrowia lipolytica in lactone accumulation and gamma-decalactone reconsumption in POX mutants. Mutants with no acyl-CoA oxidase activity could not reconsume gamma-decalactone, and mutants with a disruption of pox3, which encodes the short-chain acyl-CoA oxidase, reconsumed it more slowly. 3-Hydroxy-gamma-decalactone accumulation during transformation of methyl ricinoleate suggests that, in wild-type strains, beta-oxidation is controlled by 3-hydroxyacyl-CoA dehydrogenase. In mutants with low acyl-CoA oxidase activity, however, the acyl-CoA oxidase controls the beta-oxidation flux. We also identified mutant strains that produced 26 times more gamma-decalactone than the wild-type parents. PMID:11722925

  7. Magnetically triggered clustering of biotinylated iron oxide nanoparticles in the presence of streptavidinylated enzymes

    Science.gov (United States)

    Hodenius, Michael; Hieronymus, Thomas; Zenke, Martin; Becker, Christiane; Elling, Lothar; Bornemann, Jörg; Wong, John E.; Richtering, Walter; Himmelreich, Uwe; De Cuyper, Marcel

    2012-09-01

    This work deals with the production and characterization of water-compatible, iron oxide based nanoparticles covered with functional poly(ethylene glycol) (PEG)-biotin surface groups (SPIO-PEG-biotin). Synthesis of the functionalized colloids occurred by incubating the oleate coated particles used as precursor magnetic fluid with anionic liposomes containing 14 mol% of a phospholipid-PEG-biotin conjugate. The latter was prepared by coupling dimyristoylphosphatidylethanolamine (DC14:0PE) to activated α-biotinylamido-ω -N-hydroxy-succinimidcarbonyl-PEG (NHS-PEG-biotin). Physical characterization of the oleate and PEG-biotin iron oxide nanocolloids revealed that they appear as colloidal stable clusters with a hydrodynamic diameter of 160 nm and zeta potentials of - 39 mV (oleate coated particles) and - 14 mV (PEG-biotin covered particles), respectively, as measured by light scattering techniques. Superconducting quantum interference device (SQUID) measurements revealed specific saturation magnetizations of 62-73 emu g-1 Fe3O4 and no hysteresis was observed at 300 K. MR relaxometry at 3 T revealed very high r2 relaxivities and moderately high r1 values. Thus, both nanocolloids can be classified as small, superparamagnetic, negative MR contrast agents. The capacity to functionalize the particles was illustrated by binding streptavidin alkaline phosphatase (SAP). It was found, however, that these complexes become highly aggregated after capturing them on the magnetic filter device during high-gradient magnetophoresis, thereby reducing the accessibility of the SAP.

  8. 40 CFR 721.5762 - Aromatic aldehyde phenolic resin (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Aromatic aldehyde phenolic resin... Specific Chemical Substances § 721.5762 Aromatic aldehyde phenolic resin (generic). (a) Chemical substance... aromatic aldehyde phenolic resin (PMN P-01-573) is subject to reporting under this section for...

  9. Identification of a Substrate-binding Site in a Peroxisomal β-Oxidation Enzyme by Photoaffinity Labeling with a Novel Palmitoyl Derivative*

    OpenAIRE

    Kashiwayama, Yoshinori; Tomohiro, Takenori; Narita, Kotomi; Suzumura, Miyuki; Glumoff, Tuomo; Hiltunen, J. Kalervo; Van Veldhoven, Paul P.; Hatanaka, Yasumaru; Imanaka, Tsuneo

    2010-01-01

    Peroxisomes play an essential role in a number of important metabolic pathways including β-oxidation of fatty acids and their derivatives. Therefore, peroxisomes possess various β-oxidation enzymes and specialized fatty acid transport systems. However, the molecular mechanisms of these proteins, especially in terms of substrate binding, are still unknown. In this study, to identify the substrate-binding sites of these proteins, we synthesized a photoreactive palmitic acid analogue bearing a d...

  10. Comparative genomics of aldehyde dehydrogenase 5a1 (succinate semialdehyde dehydrogenase and accumulation of gamma-hydroxybutyrate associated with its deficiency

    Directory of Open Access Journals (Sweden)

    Malaspina Patrizia

    2009-01-01

    Full Text Available Abstract Succinic semialdehyde dehydrogenase (SSADH; aldehyde dehydrogenase 5A1 [ALDH5A1]; locus 6p22 occupies a central position in central nervous system (CNS neurotransmitter metabolism as one of two enzymes necessary for γ-aminobutyric acid (GABA recycling from the synaptic cleft. Its importance is highlighted by the neurometabolic disease associated with its inherited deficiency in humans, as well as the severe epileptic phenotype observed in Aldh5a1-/- knockout mice. Expanding evidence now suggests, however, that even subtle decreases in human SSADH activity, associated with rare and common single nucleotide polymorphisms, may produce subclinical pathological effects. SSADH, in conjunction with aldo-keto reductase 7A2 (AKR7A2, represent two neural enzymes responsible for further catabolism of succinic semialdehyde, producing either succinate (SSADH or γ-hydroxybutyrate (GHB; AKR7A2. A GABA analogue, GHB is a short-chain fatty alcohol with unusual properties in the CNS and a long pharmacological history. Moreover, SSADH occupies a further role in the CNS as the enzyme responsible for further metabolism of the lipid peroxidation aldehyde 4-hydroxy-2-nonenal (4-HNE, an intermediate known to induce oxidant stress. Accordingly, subtle decreases in SSADH activity may have the capacity to lead to regional accumulation of neurotoxic intermediates (GHB, 4-HNE. Polymorphisms in SSADH gene structure may also associate with quantitative traits, including intelligence quotient and life expectancy. Further population-based studies of human SSADH activity promise to reveal additional properties of its function and additional roles in CNS tissue.

  11. Enhanced oxidation of benzo[a]pyrene by crude enzyme extracts produced during interspecific fungal interaction of Trametes versicolor and Phanerochaete chrysosporium

    Institute of Scientific and Technical Information of China (English)

    Linbo Qian; Baoliang Chen

    2012-01-01

    The effects of interspecific fungal interactions between Trametes versicolor and Phanerochaete chrysosporium on laccase activity and enzymatic oxidation of polycyclic aromatic hydrocarbons (PAHs) were investigated.A deadlock between the two mycelia rather than replacement of one fungus by another was observed on an agar medium.The laccase activity in crude enzyme extracts from interaction zones reached a maximum after a 5-day incubation,which was significantly higher than that from regions of T.versicolor or P.chrysosporium alone.The enhanced induction of laccase activity lasted longer in half nutrition than in normal nutrition.A higher potential to oxidize benzo[a]pyrene by a crude enzyme preparation extracted from the interaction zones was demonstrated.After a 48 hr incubation period,the oxidation of benzo[a]pyrene by crude enzyme extracts from interaction zones reached 26.2%,while only 9.5% of benzo[a]pyrene was oxidized by crude extracts from T.versicolor.The oxidation was promoted by the co-oxidant 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate diammonium salt (ABTS).These findings indicate that the application of co-culturing of white-rot fungi in bioremediation is a potential ameliorating technique for the restoration of PAH-contaminated soil.

  12. PURIFICATION AND CHARACTERIZATION OF A BENZYLVIOLOGEN-LINKED, TUNGSTEN-CONTAINING ALDEHYDE OXIDOREDUCTASE FROM DESULFOVIBRIO-GIGAS

    NARCIS (Netherlands)

    HENSGENS, CMH; HAGEN, WR; HANSEN, TA

    1995-01-01

    Desulfovibrio gigas NCIMB 9332 cells grown in ethanol-containing medium with 0.1 mu M tungstate contained a benzylviologen-linked aldehyde oxidoreductase, The enzyme was purified to electrophoretic homogeneity and found to be a homodimer with a subunit M(r) of 62,000, It contained 0.68 a 0.08 W, 4.8

  13. Genome-wide identification and analysis of the aldehyde dehydrogenase (ALDH) gene superfamily in apple (Malus × domestica Borkh.).

    Science.gov (United States)

    Li, Xiaoqin; Guo, Rongrong; Li, Jun; Singer, Stacy D; Zhang, Yucheng; Yin, Xiangjing; Zheng, Yi; Fan, Chonghui; Wang, Xiping

    2013-10-01

    Aldehyde dehydrogenases (ALDHs) represent a protein superfamily encoding NAD(P)(+)-dependent enzymes that oxidize a wide range of endogenous and exogenous aliphatic and aromatic aldehydes. In plants, they are involved in many biological processes and play a role in the response to environmental stress. In this study, a total of 39 ALDH genes from ten families were identified in the apple (Malus × domestica Borkh.) genome. Synteny analysis of the apple ALDH (MdALDH) genes indicated that segmental and tandem duplications, as well as whole genome duplications, have likely contributed to the expansion and evolution of these gene families in apple. Moreover, synteny analysis between apple and Arabidopsis demonstrated that several MdALDH genes were found in the corresponding syntenic blocks of Arabidopsis, suggesting that these genes appeared before the divergence of lineages that led to apple and Arabidopsis. In addition, phylogenetic analysis, as well as comparisons of exon-intron and protein structures, provided further insight into both their evolutionary relationships and their putative functions. Tissue-specific expression analysis of the MdALDH genes demonstrated diverse spatiotemporal expression patterns, while their expression profiles under abiotic stress and various hormone treatments indicated that many MdALDH genes were responsive to high salinity and drought, as well as different plant hormones. This genome-wide identification, as well as characterization of evolutionary relationships and expression profiles, of the apple MdALDH genes will not only be useful for the further analysis of ALDH genes and their roles in stress response, but may also aid in the future improvement of apple stress tolerance.

  14. Tamarind seed coat extract restores reactive oxygen species through attenuation of glutathione level and antioxidant enzyme expression in human skin fibroblasts in response to oxidative stress

    Directory of Open Access Journals (Sweden)

    Oranuch Nakchat

    2014-05-01

    Conclusions: TSCE exhibited antioxidant activities by scavenging ROS, attenuating GSH level that could protect human skin fibroblast cells from oxidative stress. Our results highlight the antioxidant mechanism of tamarind seed coat through an antioxidant enzyme system, the extract potentially benefits for health food and cosmeceutical application of tamarind seed coat.

  15. Expression of a nitric oxide degrading enzyme induces a senescence programme in Arabidopsis.

    Science.gov (United States)

    Mishina, Tatiana E; Lamb, Chris; Zeier, Jürgen

    2007-01-01

    Nitric oxide (NO) has been proposed to act as a factor delaying leaf senescence and fruit maturation in plants. Here we show that expression of a NO degrading dioxygenase (NOD) in Arabidopsis thaliana initiates a senescence-like phenotype, an effect that proved to be more pronounced in older than in younger leaves. This senescence phenotype was preceded by a massive switch in gene expression in which photosynthetic genes were down-regulated, whereas many senescence-associated genes (SAGs) and the 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene ACS6 involved in ethylene synthesis were up-regulated. External fumigation of NOD plants with NO as well as environmental conditions known to stimulate endogenous NO production attenuated the induced senescence programme. For instance, both high light conditions and nitrate feeding reduced the senescence phenotype and attenuated the down-regulation of photosynthetic genes as well as the up-regulation of SAGs. Treatment of plants with the cytokinin 6-benzylaminopurin (BAP) reduced the down-regulation of photosynthesis, although it had no consistent effect on SAG expression. Metabolic changes during NOD-induced senescence comprehended increases in salicylic acid (SA) levels, accumulation of the phytoalexin camalexin and elevation of leaf gamma-tocopherol contents, all of which occurred during natural senescence in Arabidopsis leaves as well. Moreover, NO fumigation delayed the senescence process induced by darkening individual Arabidopsis Columbia-0 (Col-0) leaves. Our data thus support the notion that NO acts as a negative regulator of leaf senescence.

  16. Oxidative stress as a risk factor for osteoporosis in elderly Mexicans as characterized by antioxidant enzymes

    Directory of Open Access Journals (Sweden)

    Correa-Muñoz Elsa

    2007-12-01

    Full Text Available Abstract Background Oxidative stress (OxS has recently been linked with osteoporosis; however, we do not know the influence of OxS as an independent risk factor for this disease. Methods We conducted a case-control study in 94 subjects ≥60 years of age, 50 healthy and 44 with osteoporosis. We measured total antioxidant status, plasma lipid peroxides, antioxidant activity of superoxide dismutase and glutathione peroxidase (GPx, and calculated the SOD/GPx ratio. Bone mineral density was obtained at the peripheral DXA in calcaneus using a portable Norland Apollo Densitometer®. Osteoporosis was considered when subjects had a BMD of 2.5 standard deviations or more below the mean value for young adults. Results GPx antioxidant activity was significantly lower in the group of subjects with osteoporosis in comparison with the group of healthy subjects (p p p = 0.034. Conclusion Our findings suggest that OxS is an independent risk factor for osteoporosis linked to increase of SOD/GPx ratio.

  17. Organic acids and aldehydes in rainwater in a northwest region of Spain

    Energy Technology Data Exchange (ETDEWEB)

    Pena, R.M.; Garcia, S.; Herrero, C. [Universidad de Santiago de Compostela, Lugo (Spain). Departamento de Quimica Analitica, Nutricion y Bromatologia

    2002-11-01

    During a 1 year period, measurements of carboxylic acids and aldehydes were carried out in rainwater samples collected at nine different sites in NW Spain surrounding a thermal power plant in order to determine concentration levels and sources. In addition, certain major ions (Cl{sup -}, NO{sub 3}{sup -}, SO{sub 4}{sup 2-}, Na{sup +}, NH{sub 4}{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}) were also determined. Aldehyde and carboxylic acid concentration patterns and their effects on rainwater composition concerning temporal, seasonal and spatial variations were evaluated. Among carboxylic acids, formic and acetic were predominant (VWA 7.0 and 8.3 {mu}M), while formaldehyde and acroleine were the dominant aldehydes (VWA 0.42 and 1.25 {mu}M). Carboxylic acids were estimated to account for 27.5% of the total free acidity (TFA), whereas sulphuric and nitric acid accounted for 46.2% and 26.2%, respectively. Oxalic acid was demonstrated to be an important contributing compound to the acidification in rainwater representing 7.1% of the TFA. The concentration of aldehydes and carboxylic acids, which originated mainly from biogenic emissions in the area studied, was strongly dependent on the season of the year (growing and non-growing). The ratios of formic to acetic acids are considerably different in the two seasons suggesting that there exist distinct sources in both growing and non-growing seasons. Principal component analysis was applied in order to elucidate the sources of aldehydes and organic acids in rainwater. The prevalence of natural vegetative origins for both of these compounds versus anthropogenic emissions was demonstrated and the importance of the oxidation of aldehydes as a relevant source of organic acids was also established. (author)

  18. Effect of Sodium Chloride and Cadmium on the Growth, Oxidative Stress and Antioxidant Enzyme Activities of Zygosaccharomyces rouxii

    Institute of Scientific and Technical Information of China (English)

    LI Chunsheng; XU Ying; JIANG Wei; LV Xin; DONG Xiaoyan

    2014-01-01

    Zygosaccharomyces rouxii is a salt-tolerant yeast species capable of removing cadmium (Cd) pollutant from aqueous solution. Presently, the physiological characteristics of Z. rouxii under the stress of sodium chloride (NaCl) and Cd are poorly under-stood. This study investigated the effects of NaCl and Cd on the growth, oxidative stress and antioxidant enzyme activities of Z. rouxii after stress treatment for 24 h. Results showed that NaCl or Cd alone negatively affected the growth of Z. rouxii, but the growth-inhibiting effect of Cd on Z. rouxii was reduced in the presence of NaCl. Flow cytometry assay showed that under Cd stress, NaCl significantly reduced the production of reactive oxygen species (ROS) and cell death of Z. rouxii compared with those in the absence of NaCl. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) of Z. rouxii were significantly enhanced by 2%-6%NaCl, which likely contributed to the high salt tolerance of Z. rouxii. The POD activity was inhibited by 20 mg L-1 Cd while the SOD and CAT activities were enhanced by 8 mg L-1 Cd and inhibited by 20 mg L-1 or 50 mg L-1 Cd. The inhibitory ef-fect of high-level Cd on the antioxidant enzyme activities of Z. rouxii was counteracted by the combined use of NaCl, especially at 6%. This probably accounted for the decrease in Cd-induced ROS production and cell death of Z. rouxii after incubation with NaCl and Cd. Our work provided physiological clues as to the use of Z. rouxii as a biosorbent for Cd removal from seawater and liquid highly salty food.

  19. Effect of sodium chloride and cadmium on the growth, oxidative stress and antioxidant enzyme activities of Zygosaccharomyces rouxii

    Science.gov (United States)

    Li, Chunsheng; Xu, Ying; Jiang, Wei; Lv, Xin; Dong, Xiaoyan

    2014-06-01

    Zygosaccharomyces rouxii is a salt-tolerant yeast species capable of removing cadmium (Cd) pollutant from aqueous solution. Presently, the physiological characteristics of Z. rouxii under the stress of sodium chloride (NaCl) and Cd are poorly understood. This study investigated the effects of NaCl and Cd on the growth, oxidative stress and antioxidant enzyme activities of Z. rouxii after stress treatment for 24 h. Results showed that NaCl or Cd alone negatively affected the growth of Z. rouxii, but the growth-inhibiting effect of Cd on Z. rouxii was reduced in the presence of NaCl. Flow cytometry assay showed that under Cd stress, NaCl significantly reduced the production of reactive oxygen species (ROS) and cell death of Z. rouxii compared with those in the absence of NaCl. The activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) of Z. rouxii were significantly enhanced by 2%-6% NaCl, which likely contributed to the high salt tolerance of Z. rouxii. The POD activity was inhibited by 20 mg L-1 Cd while the SOD and CAT activities were enhanced by 8 mg L-1 Cd and inhibited by 20 mg L-1 or 50 mg L-1 Cd. The inhibitory effect of high-level Cd on the antioxidant enzyme activities of Z. rouxii was counteracted by the combined use of NaCl, especially at 6%. This probably accounted for the decrease in Cd-induced ROS production and cell death of Z. rouxii after incubation with NaCl and Cd. Our work provided physiological clues as to the use of Z. rouxii as a biosorbent for Cd removal from seawater and liquid highly salty food.

  20. Theoretical structural study on the adsorption properties of aliphatic aldehydes on ZnO nanoclusters and graphene-like nanosheets systems

    Science.gov (United States)

    Tayebee, R.; Zamand, N.; Hosseini-nasr, A.; Kargar Razi, M.

    2014-05-01

    The structure optimizations for some aliphatic aldehydes adsorbed on ZnO nanoclusters, and graphene-like nanosheets were carried out using the B3LYP/LanL2DZ calculations and the adsorption energies were calculated. It was considered that adsorption of the examined aldehydes on the ZnO nanoclusters and graphene-like nanosheets occurred through carbonyl oxygens of aldehyde molecules with the surface Zn2+ ions of the central ring. Aldehydes with the general formula of R-COH (R denotes a branched or linear aliphatic chain with maximum of three carbon atoms) were considered. Also, Effects of chain length were investigated on the orientation of the aldehyde molecules with respect to the nanosheet and nanocluster surfaces. Findings revealed that the adsorption energy was decreased with enhancing chain length. However, the most negative adsorption energy was obtained for iso-butyraldehyde, as a branched aldehyde. Interaction of the aldehyde molecules with the surfaces of nanosheets were analyzed by means of DOS analysis and Bader's method. We hope the obtained results be helpful in identifying the mechanism of cyclotrimerization of aliphatic aldehydes on the surface of zinc oxide nanoparticles.

  1. Creatine and pyruvate prevent the alterations caused by tyrosine on parameters of oxidative stress and enzyme activities of phosphoryltransfer network in cerebral cortex of Wistar rats.

    Science.gov (United States)

    de Andrade, Rodrigo Binkowski; Gemelli, Tanise; Rojas, Denise Bertin; Bonorino, Narielle Ferner; Costa, Bruna May Lopes; Funchal, Cláudia; Dutra-Filho, Carlos Severo; Wannmacher, Clovis Milton Duval

    2015-01-01

    Tyrosine accumulates in inborn errors of tyrosine catabolism, especially in tyrosinemia type II. In this disease caused by tyrosine aminotransferase deficiency, eyes, skin, and central nervous system disturbances are found. In the present study, we investigated the chronic effect of tyrosine methyl ester (TME) and/or creatine plus pyruvate on some parameters of oxidative stress and enzyme activities of phosphoryltransfer network in cerebral cortex homogenates of 21-day-old Wistar. Chronic administration of TME induced oxidative stress and altered the activities of adenylate kinase and mitochondrial and cytosolic creatine kinase. Total sulfhydryls content, GSH content, and GPx activity were significantly diminished, while DCFH oxidation, TBARS content, and SOD activity were significantly enhanced by TME. On the other hand, TME administration decreased the activity of CK from cytosolic and mitochondrial fractions but enhanced AK activity. In contrast, TME did not affect the carbonyl content and PK activity in cerebral cortex of rats. Co-administration of creatine plus pyruvate was effective in the prevention of alterations provoked by TME administration on the oxidative stress and the enzymes of phosphoryltransfer network, except in mitochondrial CK, AK, and SOD activities. These results indicate that chronic administration of TME may stimulate oxidative stress and alter the enzymes of phosphoryltransfer network in cerebral cortex of rats. In case this also occurs in the patients affected by these disorders, it may contribute, along with other mechanisms, to the neurological dysfunction of hypertyrosinemias, and creatine and pyruvate supplementation could be beneficial to the patients.

  2. Kinetics of Forming Aldehydes in Frying Oils and Their Distribution in French Fries Revealed by LC-MS-Based Chemometrics.

    Science.gov (United States)

    Wang, Lei; Csallany, A Saari; Kerr, Brian J; Shurson, Gerald C; Chen, Chi

    2016-05-18

    In this study, the kinetics of aldehyde formation in heated frying oils was characterized by 2-hydrazinoquinoline derivatization, liquid chromatography-mass spectrometry (LC-MS) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The aldehydes contributing to time-dependent separation of heated soybean oil (HSO) in a PCA model were grouped by the HCA into three clusters (A1, A2, and B) on the basis of their kinetics and fatty acid precursors. The increases of 4-hydroxynonenal (4-HNE) and the A2-to-B ratio in HSO were well-correlated with the duration of thermal stress. Chemometric and quantitative analysis of three frying oils (soybean, corn, and canola oils) and French fry extracts further supported the associations between aldehyde profiles and fatty acid precursors and also revealed that the concentrations of pentanal, hexanal, acrolein, and the A2-to-B ratio in French fry extracts were more comparable to their values in the frying oils than other unsaturated aldehydes. All of these results suggest the roles of specific aldehydes or aldehyde clusters as novel markers of the lipid oxidation status for frying oils or fried foods.

  3. Kinetics of Forming Aldehydes in Frying Oils and Their Distribution in French Fries Revealed by LC-MS-Based Chemometrics.

    Science.gov (United States)

    Wang, Lei; Csallany, A Saari; Kerr, Brian J; Shurson, Gerald C; Chen, Chi

    2016-05-18

    In this study, the kinetics of aldehyde formation in heated frying oils was characterized by 2-hydrazinoquinoline derivatization, liquid chromatography-mass spectrometry (LC-MS) analysis, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The aldehydes contributing to time-dependent separation of heated soybean oil (HSO) in a PCA model were grouped by the HCA into three clusters (A1, A2, and B) on the basis of their kinetics and fatty acid precursors. The increases of 4-hydroxynonenal (4-HNE) and the A2-to-B ratio in HSO were well-correlated with the duration of thermal stress. Chemometric and quantitative analysis of three frying oils (soybean, corn, and canola oils) and French fry extracts further supported the associations between aldehyde profiles and fatty acid precursors and also revealed that the concentrations of pentanal, hexanal, acrolein, and the A2-to-B ratio in French fry extracts were more comparable to their values in the frying oils than other unsaturated aldehydes. All of these results suggest the roles of specific aldehydes or aldehyde clusters as novel markers of the lipid oxidation status for frying oils or fried foods. PMID:27128101

  4. Antioxidant enzymes as potential targets in cardioprotection and treatment of cardiovascular diseases. Enzyme antioxidants: the next stage of pharmacological counterwork to the oxidative stress

    Directory of Open Access Journals (Sweden)

    Alexander V. Vavaev

    2012-02-01

    Full Text Available The focus in antioxidant research is on enzyme derivative investigations. Extracellular superoxide dismutase (EC-SOD is of particular interest, as it demonstrates in vivo the protective action against development of atherosclerosis, hypertension, heart failure, diabetes mellitus. The reliable association of coronary artery disease with decreased level of heparin-released EC-SOD was established in clinical research. To create a base for and to develop antioxidant therapy, various SOD isozymes, catalase (CAT, methods of gene therapy, and combined applications of enzymes are used. Covalent bienzyme SOD-CHS-CAT conjugate (CHS, chondroitin sulphate showed high efficacy and safety as the drug candidate. There is an evident trend to use the components of glycocalyx and extracellular matrix for target delivery of medical substances. Development of new enzyme antioxidants for therapeutic application is closely connected with progress in medical biotechnology, pharmaceutical industry, and bioeconomy.

  5. Allylation of Aromatic Aldehyde under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yu-Mei; JIA,Xue-Feng; WANG,Jin-Xian

    2004-01-01

    @@ Allylation of carbonyl compounds is one of the most interesting processes for the preparation of homoallylic alcohols. Over the past few decades, many reagents have been developed for such reactions[1~3]. In this paper, we first report allylic zinc reagent 1, which can be prepared from zinc dust and allyl bromide conveniently in THF, and reacted with aromatic aldehyde to give homo-allylic alcohols under microwave irradiation.

  6. Oxidative and nitrosative stress enzymes in relation to nitrotyrosine in Helicobacter pylori-infected humans

    Institute of Scientific and Technical Information of China (English)

    Anders; Elfvin; Anders; Edebo; Peter; Hallersund; Anna; Casselbrant; Lars; Fndriks

    2014-01-01

    AIM: To compare a possible relation between Helicobacter pylori(H. pylori) and the oxygen- and nitrogen radical system in humans. METHODS: Mechanisms for H. pylori to interfere with the oxygen and nitrogen radical system is of great importance for understanding of the H. pylori persistence and pathogenesis. Biopsies were obtained from the gastric wall of 21 individuals. Ongoing infection with H. pylori was detected using direct analyze from the biopsies using campylobacter-like organism test(CLO-test) and/or by using 14C-urea breath test. The individuals were divided in a negative H. pylori and a positive H. pylori group. Expression in the gastric mucosa of induc-ible nitric oxide syntase(iNOS), nicotinamide adenine dinucleotide phosphate-oxidase(NADPH-oxidase) myeloperoxidase(MPO), and nitrotyrosine were assessed by Western blotting.RESULTS: The individuals who undervent gastroscopy were divided in a H. pylori neg. [n = 13, m/f = 7/6, age(mean) = 39] and a H. pylori pos. group [n = 8, m/f = 5/3, age(mean) = 53]. Using western blot analysis iNOS was detected as a 130 kDa band. The iNOS expression was upregulated in the antrum of H. pylori infected individuals in comparison to the controls, mean ± SD being 12.6 ± 2.4 vs 8.3 ± 3.1, P < 0.01. There was a markedly upregulated expression of MPO in the antrum of H. pylori infected individuals in comparison to the control group without infection. In several of noninfected controls it was not possible to detect any MPO expression at all, whereas the expression was high in all the infected subjects, mean ± SD being 5.1 ± 3.4 vs 2.1 ± 1.9, P < 0.05. The NADPH-oxidase expression was analysed by detecting the NADPH-oxidase subunit p47-phox expression. P47-phox was detected as a 47 kDa band using Western blot, and showed a significantly higher expression of p47-phox in the antrum of the H. pylori infected individuals compared to the controls, mean ± SD being 3.1 ± 2.2 vs 0.3 ± 0.2, P < 0.01. Regarding nitrotyrosine

  7. Residues that influence coenzyme preference in the aldehyde dehydrogenases.

    Science.gov (United States)

    González-Segura, Lilian; Riveros-Rosas, Héctor; Julián-Sánchez, Adriana; Muñoz-Clares, Rosario A

    2015-06-01

    To find out the residues that influence the coenzyme preference of aldehyde dehydrogenases (ALDHs), we reviewed, analyzed and correlated data from their known crystal structures and amino-acid sequences with their published kinetic parameters for NAD(P)(+). We found that the conformation of the Rossmann-fold loops participating in binding the adenosine ribose is very conserved among ALDHs, so that coenzyme specificity is mainly determined by the nature of the residue at position 195 (human ALDH2 numbering). Enzymes with glutamate or proline at 195 prefer NAD(+) because the side-chains of these residues electrostatically and/or sterically repel the 2'-phosphate group of NADP(+). But contrary to the conformational rigidity of proline, the conformational flexibility of glutamate may allow NADP(+)-binding in some enzymes by moving the carboxyl group away from the 2'-phosphate group, which is possible if a small neutral residue is located at position 224, and favored if the residue at position 53 interacts with Glu195 in a NADP(+)-compatible conformation. Of the residues found at position 195, only glutamate interacts with the NAD(+)-adenosine ribose; glutamine and histidine cannot since their side-chain points are opposite to the ribose, probably because the absence of the electrostatic attraction by the conserved nearby Lys192, or its electrostatic repulsion, respectively. The shorter side-chains of other residues-aspartate, serine, threonine, alanine, valine, leucine, or isoleucine-are distant from the ribose but leave room for binding the 2'-phosphate group. Generally, enzymes having a residue different from Glu bind NAD(+) with less affinity, but they can also bind NADP(+) even sometimes with higher affinity than NAD(+), as do enzymes containing Thr/Ser/Gln195. Coenzyme preference is a variable feature within many ALDH families, consistent with being mainly dependent on a single residue that apparently has no other structural or functional roles, and therefore can

  8. Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    P. O. Wennberg

    2010-04-01

    Full Text Available Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene, the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA via methacrolein (a C4-unsaturated aldehyde under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232 is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(OOONO2 formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios, the SOA yields from isoprene high-NOxphotooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

  9. Role of aldehyde chemistry and NOx concentrations in secondary organic aerosol formation

    Directory of Open Access Journals (Sweden)

    P. O. Wennberg

    2010-08-01

    Full Text Available Aldehydes are an important class of products from atmospheric oxidation of hydrocarbons. Isoprene (2-methyl-1,3-butadiene, the most abundantly emitted atmospheric non-methane hydrocarbon, produces a significant amount of secondary organic aerosol (SOA via methacrolein (a C4-unsaturated aldehyde under urban high-NOx conditions. Previously, we have identified peroxy methacryloyl nitrate (MPAN as the important intermediate to isoprene and methacrolein SOA in this NOx regime. Here we show that as a result of this chemistry, NO2 enhances SOA formation from methacrolein and two other α, β-unsaturated aldehydes, specifically acrolein and crotonaldehyde, a NOx effect on SOA formation previously unrecognized. Oligoesters of dihydroxycarboxylic acids and hydroxynitrooxycarboxylic acids are observed to increase with increasing NO2/NO ratio, and previous characterizations are confirmed by both online and offline high-resolution mass spectrometry techniques. Molecular structure also determines the amount of SOA formation, as the SOA mass yields are the highest for aldehydes that are α, β-unsaturated and contain an additional methyl group on the α-carbon. Aerosol formation from 2-methyl-3-buten-2-ol (MBO232 is insignificant, even under high-NO2 conditions, as PAN (peroxy acyl nitrate, RC(OOONO2 formation is structurally unfavorable. At atmospherically relevant NO2/NO ratios (3–8, the SOA yields from isoprene high-NOx photooxidation are 3 times greater than previously measured at lower NO2/NO ratios. At sufficiently high NO2 concentrations, in systems of α, β-unsaturated aldehydes, SOA formation from subsequent oxidation of products from acyl peroxyl radicals+NO2 can exceed that from RO2+HO2 reactions under the same inorganic seed conditions, making RO2+NO2 an important channel for SOA formation.

  10. Phenolic Extract from Moringa oleifera Leaves Inhibits Key Enzymes Linked to Erectile Dysfunction and Oxidative Stress in Rats' Penile Tissues

    Science.gov (United States)

    Oboh, Ganiyu; Ademiluyi, Adedayo O.; Ademosun, Ayokunle O.; Olasehinde, Tosin A.; Oyeleye, Sunday I.; Boligon, Aline A.; Athayde, Margareth L.

    2015-01-01

    This study was designed to determine the antioxidant properties and inhibitory effects of extract from Moringa oleifera leaves on angiotensin-I-converting enzyme (ACE) and arginase activities in vitro. The extract was prepared and phenolic (total phenols and flavonoid) contents, radical (nitric oxide (NO), hydroxyl (OH)) scavenging abilities, and Fe2+-chelating ability were assessed. Characterization of the phenolic constituents was done via high performance liquid chromatography-diode array detection (HPLC-DAD) analysis. Furthermore, the effects of the extract on Fe2+-induced MDA production in rats' penile tissue homogenate as well as its action on ACE and arginase activities were also determined. The extract scavenged NO∗, OH∗, chelated Fe2+, and inhibited MDA production in a dose-dependent pattern with IC50 values of 1.36, 0.52, and 0.38 mg/mL and 194.23 µg/mL, respectively. Gallic acid, chlorogenic acid, quercetin, and kaempferol were the most abundant phenolic compounds identified in the leaf extract. The extract also inhibited ACE and arginase activities in a dose-dependent pattern and their IC50 values were 303.03 and 159.59 µg/mL, respectively. The phenolic contents, inhibition of ACE, arginase, and Fe2+-induced MDA production, and radical (OH∗, NO∗) scavenging and Fe2+-chelating abilities could be some of the possible mechanisms by which M. oleifera leaves could be used in the treatment and/or management of erectile dysfunction. PMID:26557995

  11. The effect of heavy metal-induced oxidative stress on the enzymes in white rot fungus Phanerochaete chrysosporium.

    Science.gov (United States)

    Zhang, Qihua; Zeng, Guangming; Chen, Guiqiu; Yan, Min; Chen, Anwei; Du, Jianjian; Huang, Jian; Yi, Bin; Zhou, Ying; He, Xiaoxiao; He, Yan

    2015-02-01

    Prevalence of heavy metals in the living environment causes chemical stress and reactive oxygen species (ROS) formation in Phanerochaete chrysosporium (P. chrysosporium). However, the mechanisms involved in ROS defense are still under investigation. In the present study, we evaluated the effect of lead- and cadmium-induced oxidative stress on the activities of catalase (CAT), peroxidase (POD), lignin peroxidase (LiP), and manganese peroxidase (MnP). A time-dependent change in all enzyme activities was observed following exposure to 50 μM cadmium and 25 μM lead. The lowest values were recorded at 4 h after exposure. Both cadmium and lead inhibited CAT and POD. The cytochrome P450 (CYP450) levels increased under 50-100 μM cadmium or lead exposure and decreased when heavy metal concentration was under 50 μM; this suggested that ROS is not the only factor that alters the CYP450 levels. The cadmium removal rate in the sample containing 900 μM taxifolin (inhibitor of CYP450) and 100 μM cadmium was reduced to 12.34 %, 9.73 % lower than that of 100 μM cadmium-induced sample, indicating CYP450 may play an indirect but key role in the process of clearance of heavy metals. The pH of the substrate solution decreased steadily during the incubation process.

  12. Phenolic Extract from Moringa oleifera Leaves Inhibits Key Enzymes Linked to Erectile Dysfunction and Oxidative Stress in Rats’ Penile Tissues

    Directory of Open Access Journals (Sweden)

    Ganiyu Oboh

    2015-01-01

    Full Text Available This study was designed to determine the antioxidant properties and inhibitory effects of extract from Moringa oleifera leaves on angiotensin-I-converting enzyme (ACE and arginase activities in vitro. The extract was prepared and phenolic (total phenols and flavonoid contents, radical (nitric oxide (NO, hydroxyl (OH scavenging abilities, and Fe2+-chelating ability were assessed. Characterization of the phenolic constituents was done via high performance liquid chromatography-diode array detection (HPLC-DAD analysis. Furthermore, the effects of the extract on Fe2+-induced MDA production in rats’ penile tissue homogenate as well as its action on ACE and arginase activities were also determined. The extract scavenged NO∗, OH∗, chelated Fe2+, and inhibited MDA production in a dose-dependent pattern with IC50 values of 1.36, 0.52, and 0.38 mg/mL and 194.23 µg/mL, respectively. Gallic acid, chlorogenic acid, quercetin, and kaempferol were the most abundant phenolic compounds identified in the leaf extract. The extract also inhibited ACE and arginase activities in a dose-dependent pattern and their IC50 values were 303.03 and 159.59 µg/mL, respectively. The phenolic contents, inhibition of ACE, arginase, and Fe2+-induced MDA production, and radical (OH∗, NO∗ scavenging and Fe2+-chelating abilities could be some of the possible mechanisms by which M. oleifera leaves could be used in the treatment and/or management of erectile dysfunction.

  13. Amplified inhibition of the electrochemical signal of ferrocene by enzyme-functionalized graphene oxide nanoprobe for ultrasensitive immunoassay.

    Science.gov (United States)

    Lai, Guosong; Cheng, Hui; Xin, Dinghong; Zhang, Haili; Yu, Aimin

    2016-01-01

    A nanoprobe-induced signal inhibition mechanism was designed for ultrasensitive electrochemical immunoassay at a chitosan-ferrocene (CS-Fc) based immunosensor. The nanoprobe was prepared by covalently loading signal antibody and high-content horseradish peroxidase (HRP) on the graphene oxide (GO) nanocarrier. The immunosensor was prepared through the stepwise assembly of gold nanoparticles (Au NPs) and capture antibody at a CS-Fc modified electrode. After sandwich immunoreaction, the GO-HRP nanoprobes were quantitatively captured onto the immunosensor surface and thus induced the production of a layer of insoluble film through the enzymatically catalytic reaction of the HRP labels. Both the dielectric immunocomplex formed on the immunosensor surface and the enzymatic precipitate with low electroconductivity led to the electrochemical signal decease of the Fc indicator, which was greatly amplified by the multi-enzyme signal amplification of the nanoprobe. Based on this amplified signal inhibition mechanism, a new ultrasensitive electrochemical immunoassay method was developed. Using carcinoembryonic antigen as a model analyte, this method showed a wide linear range over 5 orders of magnitude with a detection limit down to 0.54 pg/mL. Besides, the immunosensor showed good specificity, acceptable reproducibility and stability as well as satisfactory reliability for the serum sample analysis.

  14. The roles of bacterial biofilm and oxidizing enzymes in the biodegradation of plastic by the bacterium Rhodococcus ruber (C208)

    Science.gov (United States)

    Sivan, A.; Gilan, I.; Santo, M.

    2011-12-01

    novel method for isolating mutants impaired in their production of biofilms (but not in their growth performance) was developed and utilized to isolate such mutants. Indeed, combining the Crystal Violet staining with confocal microscopy we were able to show that such mutants, not only contains reduced amounts of biofilm but also alters biofilm architecture. The above characterization of wild type and mutant strains can be utilized to determine the role of biofilm on the biodegradation of polyethylene. C208 produces laccase (phenol oxidase). This is an oxidizing enzyme that requires copper for induction and activity. In the presence of copper the biodegradation of mineral oil and of polyethylene, by C208, increased by up to 25% and 100%, respectively. Treatment of polyethylene films with a cell free-extract of laccase resulted in an increase of more then 40% in the carbonyl peak (indicating oxidation) as measured by FTIR. Furthermore, during 2 weeks of incubation, with C208 laccase, the molecular weight of polyethylene was reduced by 25%. It seems that laccase alone could not account for all degrading activity and, presumably, more enzyme(s) capable of degrading olefins are yet to be discovered.

  15. Association between maternal micronutrient status, oxidative stress, and common genetic variants in antioxidant enzymes at 15 weeks׳ gestation in nulliparous women who subsequently develop preeclampsia.

    Science.gov (United States)

    Mistry, Hiten D; Gill, Carolyn A; Kurlak, Lesia O; Seed, Paul T; Hesketh, John E; Méplan, Catherine; Schomburg, Lutz; Chappell, Lucy C; Morgan, Linda; Poston, Lucilla

    2015-01-01

    Preeclampsia is a pregnancy-specific condition affecting 2-7% of women and a leading cause of perinatal and maternal morbidity and mortality. Deficiencies of specific micronutrient antioxidant activities associated with copper, selenium, zinc, and manganese have previously been linked to preeclampsia at the time of disease. Our aims were to investigate whether maternal plasma micronutrient concentrations and related antioxidant enzyme activities are altered before preeclampsia onset and to examine the dependence on genetic variations in these antioxidant enzymes. Predisease plasma samples (15±1 weeks׳ gestation) were obtained from women enrolled in the international Screening for Pregnancy Endpoints (SCOPE) study who subsequently developed preeclampsia (n=244) and from age- and BMI-matched normotensive controls (n=472). Micronutrient concentrations were measured by inductively coupled plasma mass spectrometry; associated antioxidant enzyme activities, selenoprotein-P, ceruloplasmin concentration and activity, antioxidant capacity, and markers of oxidative stress were measured by colorimetric assays. Sixty-four tag-single-nucleotide polymorphisms (SNPs) within genes encoding the antioxidant enzymes and selenoprotein-P were genotyped using allele-specific competitive PCR. Plasma copper and ceruloplasmin concentrations were modestly but significantly elevated in women who subsequently developed preeclampsia (both Ppreeclampsia. The modest elevation in copper may contribute to oxidative stress, later in pregnancy, in those women that go on to develop preeclampsia. The lack of evidence to support the hypothesis that functional SNPs influence antioxidant enzyme activity in pregnant women argues against a role for these genes in the etiology of preeclampsia.

  16. Analysis of endogenous aldehydes in human urine by static headspace gas chromatography-mass spectrometry.

    Science.gov (United States)

    Serrano, María; Gallego, Mercedes; Silva, Manuel

    2016-03-11

    Endogenous aldehydes (EAs) generated during oxidative stress and cell processes are associated with many pathogenic and toxicogenic processes. The aim of this research was to develop a solvent-free and automated analytical method for the determination of EAs in human urine using a static headspace generator sampler coupled with gas chromatography-mass spectrometry (HS-GC-MS). Twelve significant EAs used as markers of different biochemical and physiological processes, namely short- and medium-chain alkanals, α,β-unsaturated aldehydes and dicarbonyl aldehydes have been selected as target analytes. Human urine samples (no dilution is required) were derivatized with O-2,3,4,5,6-pentafluorobenzylhydroxylamine in alkaline medium (hydrogen carbonate-carbonate buffer, pH 10.3). The HS-GC-MS method developed renders an efficient tool for the sensitive and precise determination of EAs in human urine with limits of detection from 1 to 15ng/L and relative standard deviations, (RSDs) from 6.0 to 7.9%. Average recoveries by enriching urine samples ranged between 92 and 95%. Aldehydes were readily determined at 0.005-50μg/L levels in human urine from healthy subjects, smokers and diabetic adults.

  17. Study on physico-chemical properties of dialdehyde yam starch with different aldehyde group contents

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liming, E-mail: zhanglmd@yahoo.com.cn [Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457 (China); Liu, Peng; Wang, Yugao [College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457 (China); Gao, Wenyuan [Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457 (China)

    2011-01-10

    Dialdehyde yam starches (DASs) are prepared and characterized. Compared with native starch, viscosity average molecular weight of DASs decreases, and the extent of degradation depends on content of the aldehyde groups. Fourier transform infrared (FT-IR) spectra confirm that the characteristic peak for C=O group at 1732 cm{sup -1} is enhanced with the increasing of content of the aldehyde groups. Scanning electron microscopy (SEM) micrographs show that the surface of starch granules becomes wrinkled. X-ray diffraction (XRD) patterns clearly indicate that their crystallinity decreases with the increasing content of the aldehyde groups before they become amorphous at higher oxidation states. The experimental results of thermogravimetric analysis (TGA) show that DASs have poor stability as compared to native starch. With the increase in content of the aldehyde groups, the thermal stability of DAS declines gradually. According to the results of differential scanning calorimetry (DSC), gelatinization temperature (T{sub o} and T{sub p}) of DASs are increased, whereas the gelatinization enthalpy decreased.

  18. Curcumin Induces Nrf2 Nuclear Translocation and Prevents Glomerular Hypertension, Hyperfiltration, Oxidant Stress, and the Decrease in Antioxidant Enzymes in 5/6 Nephrectomized Rats

    Directory of Open Access Journals (Sweden)

    Edilia Tapia

    2012-01-01

    Full Text Available Renal injury resulting from renal ablation induced by 5/6 nephrectomy (5/6NX is associated with oxidant stress, glomerular hypertension, hyperfiltration, and impaired Nrf2-Keap1 pathway. The purpose of this work was to know if the bifunctional antioxidant curcumin may induce nuclear translocation of Nrf2 and prevents 5/6NX-induced oxidant stress, renal injury, decrease in antioxidant enzymes, and glomerular hypertension and hyperfiltration. Four groups of rats were studied: (1 control, (2 5/6NX, (3 5/6NX +CUR, and (4 CUR (n=8–10. Curcumin was given by gavage to NX5/6 +CUR and CUR groups (60 mg/kg/day starting seven days before surgery. Rats were studied 30 days after NX5/6 or sham surgery. Curcumin attenuated 5/6NX-induced proteinuria, systemic and glomerular hypertension, hyperfiltration, glomerular sclerosis, interstitial fibrosis, interstitial inflammation, and increase in plasma creatinine and blood urea nitrogen. This protective effect was associated with enhanced nuclear translocation of Nrf2 and with prevention of 5/6NX-induced oxidant stress and decrease in the activity of antioxidant enzymes. It is concluded that the protective effect of curcumin against 5/6NX-induced glomerular and systemic hypertension, hyperfiltration, renal dysfunction, and renal injury was associated with the nuclear translocation of Nrf2 and the prevention of both oxidant stress and the decrease of antioxidant enzymes.

  19. Benzene Exposure Alters Expression of Enzymes Involved in Fatty Acid β-Oxidation in Male C3H/He Mice

    Directory of Open Access Journals (Sweden)

    Rongli Sun

    2016-10-01

    Full Text Available Benzene is a well-known hematotoxic carcinogen that can cause leukemia and a variety of blood disorders. Our previous study indicated that benzene disturbs levels of metabolites in the fatty acid β-oxidation (FAO pathway, which is crucial for the maintenance and function of hematopoietic and leukemic cells. The present research aims to investigate the effects of benzene on changes in the expression of key enzymes in the FAO pathway in male C3H/He mice. Results showed that benzene exposure caused reduced peripheral white blood cell (WBC, red blood cell (RBC, platelet (Pit counts, and hemoglobin (Hgb concentration. Investigation of the effects of benzene on the expression of FA transport- and β-oxidation-related enzymes showed that expression of proteins Cpt1a, Crat, Acaa2, Aldh1l2, Acadvl, Crot, Echs1, and Hadha was significantly increased. The ATP levels and mitochondrial membrane potential decreased in mice exposed to benzene. Meanwhile, reactive oxygen species (ROS, hydrogen peroxide (H2O2, and malondialdehyde (MDA levels were significantly increased in the benzene group. Our results indicate that benzene induces increased expression of FA transport and β-oxidation enzymes, mitochondrial dysfunction, and oxidative stress, which may play a role in benzene-induced hematotoxicity.

  20. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18mg Mn-oxide NPs/kg shows enhanced (Pfeed conversion ratio (FCR) were observed in prawn fed with different diets. Additionally, prawns fed with 3.0-18mg/kg Mn-oxide NPs supplemented diets achieved significant (PCAT) metabolic enzymes status in muscle and hepatopancreas showed no significant (P>0.05) alterations in prawns fed with 3.0-18mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system. PMID:27049122

  1. Zinc oxide-montmorillonite hybrid influences diarrhea, intestinal mucosal integrity, and digestive enzyme activity in weaned pigs.

    Science.gov (United States)

    Hu, Caihong; Song, Juan; You, Zhaotong; Luan, Zhaoshuang; Li, Weifen

    2012-11-01

    One hundred-eighty piglets (Duroc × Landrace × Yorkshire), with an average initial weight of 7.4 kg weaned at 27 ± 1 days of age, were used to evaluate the effects of dietary zinc oxide-montmorillonite hybrid (ZnO-MMT) on growth performance, diarrhea, intestinal mucosal integrity, and digestive enzyme activity. All pigs were allotted to five treatments and fed with the basal diets supplemented with 0, 250, 500, and 750 mg/kg of Zn as ZnO-MMT or 2,000 mg/kg of Zn as ZnO. The results showed that supplementation with 500 or 750 mg/kg of Zn from ZnO-MMT and 2,000 mg/kg of Zn from ZnO improved average daily gain, enhanced average daily feed intake, decreased fecal scores at 4, 8, and 14 days postweaning, reduced intestinal permeability which was evident from the reduced lactulose recovery and urinary lactulose/mannitol ratio, and improved the activities of protease, amylase, lipase, trypsin, and chymotrypsin both in pancreas and small intestinal contents of pigs as compared with the control. Supplemental 250 mg/kg of Zn from ZnO-MMT also decreased fecal scores at 8 and 14 days postweaning, decreased urinary lactulose/mannitol ratio, and improved chymotrypsin activity in pancreas and small intestinal contents as well as protease activity in small intestinal contents compared with control. Moreover, the above indexes of weanling pigs fed with 500 or 750 mg/kg of Zn as ZnO-MMT did not differ from those fed with 2,000 mg/kg of Zn as ZnO. The results demonstrated that supplementation with 500 or 750 mg/kg of Zn from ZnO-MMT was as efficacious as 2,000 mg/kg of Zn from ZnO in improving growth performance, alleviating postweaning diarrhea, and enhancing intestinal mucosal integrity and the digestive enzyme activities in pancreas and small intestinal contents of pigs. The results that feeding lower concentrations of ZnO-MMT to weanling pigs maintained performance will be beneficial for the environment and for sustaining swine production. PMID:22539019

  2. Biomass Vanillin-Derived Polymeric Microspheres Containing Functional Aldehyde Groups: Preparation, Characterization, and Application as Adsorbent.

    Science.gov (United States)

    Zhang, Huanyu; Yong, Xueyong; Zhou, Jinyong; Deng, Jianping; Wu, Youping

    2016-02-01

    The contribution reports the first polymeric microspheres derived from a biomass, vanillin. It reacted with methacryloyl chloride, providing monomer vanillin methacrylate (VMA), which underwent suspension polymerization in aqueous media and yielded microspheres in high yield (>90 wt %). By controlling the N2 bubbling mode and by optimizing the cosolvent for dissolving the solid monomer, the microspheres were endowed with surface pores, demonstrated by SEM images and mercury intrusion porosimetry measurement. Taking advantage of the reactive aldehyde groups, the microspheres further reacted with glycine, thereby leading to a novel type of Schiff-base chelating material. The functionalized microspheres demonstrated remarkable adsorption toward Cu(2+) (maximum, 135 mg/g) which was taken as representative for metal ions. The present study provides an unprecedented class of biobased polymeric microspheres showing large potentials as adsorbents in wastewater treatment. Also importantly, the reactive aldehyde groups may enable the microspheres to be used as novel materials for immobilizing biomacromolecules, e.g. enzymes.

  3. Biomass Vanillin-Derived Polymeric Microspheres Containing Functional Aldehyde Groups: Preparation, Characterization, and Application as Adsorbent.

    Science.gov (United States)

    Zhang, Huanyu; Yong, Xueyong; Zhou, Jinyong; Deng, Jianping; Wu, Youping

    2016-02-01

    The contribution reports the first polymeric microspheres derived from a biomass, vanillin. It reacted with methacryloyl chloride, providing monomer vanillin methacrylate (VMA), which underwent suspension polymerization in aqueous media and yielded microspheres in high yield (>90 wt %). By controlling the N2 bubbling mode and by optimizing the cosolvent for dissolving the solid monomer, the microspheres were endowed with surface pores, demonstrated by SEM images and mercury intrusion porosimetry measurement. Taking advantage of the reactive aldehyde groups, the microspheres further reacted with glycine, thereby leading to a novel type of Schiff-base chelating material. The functionalized microspheres demonstrated remarkable adsorption toward Cu(2+) (maximum, 135 mg/g) which was taken as representative for metal ions. The present study provides an unprecedented class of biobased polymeric microspheres showing large potentials as adsorbents in wastewater treatment. Also importantly, the reactive aldehyde groups may enable the microspheres to be used as novel materials for immobilizing biomacromolecules, e.g. enzymes. PMID:26752344

  4. Potent inhibition of aldehyde dehydrogenase-2 by diphenyleneiodonium: focus on nitroglycerin bioactivation.

    Science.gov (United States)

    Neubauer, Regina; Neubauer, Andrea; Wölkart, Gerald; Schwarzenegger, Christine; Lang, Barbara; Schmidt, Kurt; Russwurm, Michael; Koesling, Doris; Gorren, Antonius C F; Schrammel, Astrid; Mayer, Bernd

    2013-09-01

    Aldehyde dehydrogenase-2 (ALDH2) catalyzes vascular bioactivation of the antianginal drug nitroglycerin (GTN) to yield nitric oxide (NO) or a related species that activates soluble guanylate cyclase (sGC), resulting in cGMP-mediated vasodilation. Accordingly, established ALDH2 inhibitors attenuate GTN-induced vasorelaxation in vitro and in vivo. However, the ALDH2 hypothesis has not been reconciled with early studies demonstrating potent inhibition of the GTN response by diphenyleneiodonium (DPI), a widely used inhibitor of flavoproteins, in particular NADPH oxidases. We addressed this issue and investigated the effects of DPI on GTN-induced relaxation of rat aortic rings and the function of purified ALDH2. DPI (0.3 µM) inhibited the high affinity component of aortic relaxation to GTN without affecting the response to NO, indicating that the drug interfered with GTN bioactivation. Denitration and bioactivation of 1-2 µM GTN, assayed as 1,2-glycerol dinitrate formation and activation of purified sGC, respectively, were inhibited by DPI with a half-maximally active concentration of about 0.2 µM in a GTN-competitive manner. Molecular modeling indicated that DPI binds to the catalytic site of ALDH2, and this was confirmed by experiments showing substrate-competitive inhibition of the dehydrogenase and esterase activities of the enzyme. Our data identify ALDH2 as highly sensitive target of DPI and explain inhibition of GTN-induced relaxation by this drug observed previously. In addition, the data provide new evidence for the essential role of ALDH2 in GTN bioactivation and may have implications to other fields of ALDH2 research, such as hepatic ethanol metabolism and cardiac ischemia/reperfusion injury.

  5. Aldehyde dehydrogenase-independent bioactivation of nitroglycerin in porcine and bovine blood vessels.

    Science.gov (United States)

    Neubauer, Regina; Wölkart, Gerald; Opelt, Marissa; Schwarzenegger, Christine; Hofinger, Marielies; Neubauer, Andrea; Kollau, Alexander; Schmidt, Kurt; Schrammel, Astrid; Mayer, Bernd

    2015-02-15

    The vascular bioactivation of the antianginal drug nitroglycerin (GTN), yielding 1,2-glycerol dinitrate and nitric oxide or a related activator of soluble guanylate cyclase, is catalyzed by aldehyde dehydrogenase-2 (ALDH2) in rodent and human blood vessels. The essential role of ALDH2 has been confirmed in many studies and is considered as general principle of GTN-induced vasodilation in mammals. However, this view is challenged by an early report showing that diphenyleneiodonium, which we recently characterized as potent ALDH2 inhibitor, has no effect on GTN-induced relaxation of bovine coronary arteries (De La Lande et al., 1996). We investigated this issue and found that inhibition of ALDH2 attenuates GTN-induced coronary vasodilation in isolated perfused rat hearts but has no effect on relaxation to GTN of bovine and porcine coronary arteries. This observation is explained by low levels of ALDH2 protein expression in bovine coronary arteries and several types of porcine blood vessels. ALDH2 mRNA expression and the rates of GTN denitration were similarly low, excluding a significant contribution of ALDH2 to the bioactivation of GTN in these vessels. Attempts to identify the responsible pathway with enzyme inhibitors did not provide conclusive evidence for the involvement of ALDH3A1, cytochrome P450, or GSH-S-transferase. Thus, the present manuscript describes a hitherto unrecognized pathway of GTN bioactivation in bovine and porcine blood vessels. If present in the human vasculature, this pathway might contribute to the therapeutic effects of organic nitrates that are not metabolized by ALDH2.

  6. Role of vitamin B6 status on antioxidant defenses, glutathione, and related enzyme activities in mice with homocysteine-induced oxidative stress

    OpenAIRE

    Huang, Yi-Chia; Hsu, Cheng-Chin; Cheng, Chien-Hsiang; Hsu, Chin-Lin; Lee, Wan-Ju; Huang, Shih-Chien

    2015-01-01

    Background: Vitamin B6 may directly or indirectly play a role in oxidative stress and the antioxidant defense system.Objective: The purpose of this study was to examine the associations of vitamin B6 status with cysteine, glutathione, and its related enzyme activities in mice with homocysteine-induced oxidative stress.Design: Four-week-old male BALB/c mice were weighed and divided into one of four dietary treatment groups fed either a normal diet (as a control group and a homocysteine group),...

  7. Exogenous Nitric Oxide Alleviated the Inhibition of Photosynthesis and Antioxidant Enzyme Activities in Iron-Deficient Chinese Cabbage(Brassica chinensis L.)

    Institute of Scientific and Technical Information of China (English)

    DING Fei; WANG Xiu-feng; SHI Qing-hua; WANG Mei-ling; YANG Feng-juan; GAO Qing-hai

    2008-01-01

    The effects of exogenous nitric oxide(NO)on plant growth,chlorophyll contents,photosynthetic and chlorophyll fluorescence parameters as well as lipid peroxidation and activities of antioxidant enzymes were investigated in Chinese cabbage plants exposed to iron(Fe)deficiency.Iron deficiency led to serious chlorosis in Chinese cabbage leaves,and resulted in significant decrease in plant growth,photosynthetic pigments,net photosynthetic rate,Fv/Fm,ΦPsⅡand activities of antioxidant enzymes,and increase in lipid peroxidation.While treatment with SNP,a NO donor,it could revert the iron deficiency symptoms,increased photosynthetic rate as well as activities of antioxidant enzymes,and protected membrane from lipid peroxidation,as a result,the growth inhibition of Chinese cabbage by Fe deficiency was alleviated.

  8. Acute liver failure in rats activates glutamine-glutamate cycle but declines antioxidant enzymes to induce oxidative stress in cerebral cortex and cerebellum.

    Directory of Open Access Journals (Sweden)

    Santosh Singh

    Full Text Available BACKGROUND AND PURPOSE: Liver dysfunction led hyperammonemia (HA causes a nervous system disorder; hepatic encephalopathy (HE. In the brain, ammonia induced glutamate-excitotoxicity and oxidative stress are considered to play important roles in the pathogenesis of HE. The brain ammonia metabolism and antioxidant enzymes constitute the main components of this mechanism; however, need to be defined in a suitable animal model. This study was aimed to examine this aspect in the rats with acute liver failure (ALF. METHODS: ALF in the rats was induced by intraperitoneal administration of 300 mg thioacetamide/Kg. b.w up to 2 days. Glutamine synthetase (GS and glutaminase (GA, the two brain ammonia metabolizing enzymes vis a vis ammonia and glutamate levels and profiles of all the antioxidant enzymes vis a vis oxidative stress markers were measured in the cerebral cortex and cerebellum of the control and the ALF rats. RESULTS: The ALF rats showed significantly increased levels of ammonia in the blood (HA but little changes in the cortex and cerebellum. This was consistent with the activation of the GS-GA cycle and static levels of glutamate in these brain regions. However, significantly increased levels of lipid peroxidation and protein carbonyl contents were consistent with the reduced levels of all the antioxidant enzymes in both the brain regions of these ALF rats. CONCLUSION: ALF activates the GS-GA cycle to metabolize excess ammonia and thereby, maintains static levels of ammonia and glutamate in the cerebral cortex and cerebellum. Moreover, ALF induces oxidative stress by reducing the levels of all the antioxidant enzymes which is likely to play important role, independent of glutamate levels, in the pathogenesis of acute HE.

  9. Biogenic aldehyde determination by reactive paper spray ionization mass spectrometry

    International Nuclear Information System (INIS)

    Highlights: • In-situ derivatization and simultaneous ionization used to detect aldehydes. • Biogenic aliphatic and aromatic aldehydes reacted with 4-aminophenol. • Derivatized products yield structurally characteristic fragment ions. • This measurement demonstrated using a miniaturized portable mass spectrometer. - Abstract: Ionization of aliphatic and aromatic aldehydes is improved by performing simultaneous chemical derivatization using 4-aminophenol to produce charged iminium ions during paper spray ionization. Accelerated reactions occur in the microdroplets generated during the paper spray ionization event for the tested aldehydes (formaldehyde, n-pentanaldehyde, n-nonanaldehyde, n-decanaldehyde, n-dodecanaldehyde, benzaldehyde, m-anisaldehyde, and p-hydroxybenzaldehyde). Tandem mass spectrometric analysis of the iminium ions using collision-induced dissociation demonstrated that straight chain aldehydes give a characteristic fragment at m/z 122 (shown to correspond to protonated 4-(methyleneamino)phenol), while the aromatic aldehyde iminium ions fragment to give a characteristic product ion at m/z 120. These features allow straightforward identification of linear and aromatic aldehydes. Quantitative analysis of n-nonaldehyde using a benchtop mass spectrometer demonstrated a linear response over 3 orders of magnitude from 2.5 ng to 5 μg of aldehyde loaded on the filter paper emitter. The limit of detection was determined to be 2.2 ng for this aldehyde. The method had a precision of 22%, relative standard deviation. The experiment was also implemented using a portable ion trap mass spectrometer

  10. Biogenic aldehyde determination by reactive paper spray ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bag, Soumabha; Hendricks, P.I. [Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907 (United States); Reynolds, J.C. [Centre for Analytical Science, Loughborough University, Loughborough, Leicestershire (United Kingdom); Cooks, R.G., E-mail: cooks@purdue.edu [Aston Labs, Department of Chemistry, Purdue University, West Lafayette, IN 47907 (United States)

    2015-02-20

    Highlights: • In-situ derivatization and simultaneous ionization used to detect aldehydes. • Biogenic aliphatic and aromatic aldehydes reacted with 4-aminophenol. • Derivatized products yield structurally characteristic fragment ions. • This measurement demonstrated using a miniaturized portable mass spectrometer. - Abstract: Ionization of aliphatic and aromatic aldehydes is improved by performing simultaneous chemical derivatization using 4-aminophenol to produce charged iminium ions during paper spray ionization. Accelerated reactions occur in the microdroplets generated during the paper spray ionization event for the tested aldehydes (formaldehyde, n-pentanaldehyde, n-nonanaldehyde, n-decanaldehyde, n-dodecanaldehyde, benzaldehyde, m-anisaldehyde, and p-hydroxybenzaldehyde). Tandem mass spectrometric analysis of the iminium ions using collision-induced dissociation demonstrated that straight chain aldehydes give a characteristic fragment at m/z 122 (shown to correspond to protonated 4-(methyleneamino)phenol), while the aromatic aldehyde iminium ions fragment to give a characteristic product ion at m/z 120. These features allow straightforward identification of linear and aromatic aldehydes. Quantitative analysis of n-nonaldehyde using a benchtop mass spectrometer demonstrated a linear response over 3 orders of magnitude from 2.5 ng to 5 μg of aldehyde loaded on the filter paper emitter. The limit of detection was determined to be 2.2 ng for this aldehyde. The method had a precision of 22%, relative standard deviation. The experiment was also implemented using a portable ion trap mass spectrometer.

  11. Alcohol dehydrogenase and aldehyde dehydrogenase gene polymorphisms, alcohol intake and the risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition study

    DEFF Research Database (Denmark)

    Ferrari, P.; McKay, J. D.; Jenab, M.;

    2012-01-01

    BACKGROUND/OBJECTIVES: Heavy alcohol drinking is a risk factor of colorectal cancer (CRC), but little is known on the effect of polymorphisms in the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) on the alcohol-related risk of CRC in Caucasian populati......BACKGROUND/OBJECTIVES: Heavy alcohol drinking is a risk factor of colorectal cancer (CRC), but little is known on the effect of polymorphisms in the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) on the alcohol-related risk of CRC in Caucasian...

  12. Toluene-4-monooxygenase, a three-component enzyme system that catalyzes the oxidation of toluene to p-cresol in Pseudomonas mendocina KR1.

    OpenAIRE

    Whited, G M; Gibson, D T

    1991-01-01

    Pseudomonas mendocina KR1 grows on toluene as a sole carbon and energy source. A multicomponent oxygenase was partially purified from toluene-grown cells and separated into three protein components. The reconstituted enzyme system, in the presence of NADH and Fe2+, oxidized toluene to p-cresol as the first detectable product. Experiments with p-deutero-toluene led to the isolation of p-cresol which retained 68% of the deuterium initially present in the parent molecule. When the reconstituted ...

  13. The putative endoglucanase PcGH61D from Phanerochaete chrysosporium is a metal-dependent oxidative enzyme that cleaves cellulose.

    Directory of Open Access Journals (Sweden)

    Bjørge Westereng

    Full Text Available Many fungi growing on plant biomass produce proteins currently classified as glycoside hydrolase family 61 (GH61, some of which are known to act synergistically with cellulases. In this study we show that PcGH61D, the gene product of an open reading frame in the genome of Phanerochaete chrysosporium, is an enzyme that cleaves cellulose using a metal-dependent oxidative mechanism that leads to generation of aldonic acids. The activity of this enzyme and its beneficial effect on the efficiency of classical cellulases are stimulated by the presence of electron donors. Experiments with reduced cellulose confirmed the oxidative nature of the reaction catalyzed by PcGH61D and indicated that the enzyme may be capable of penetrating into the substrate. Considering the abundance of GH61-encoding genes in fungi and genes encoding their functional bacterial homologues currently classified as carbohydrate binding modules family 33 (CBM33, this enzyme activity is likely to turn out as a major determinant of microbial biomass-degrading efficiency.

  14. Tea Catechins Protect Goat Skeletal Muscle against H₂O₂-Induced Oxidative Stress by Modulating Expression of Phase 2 Antioxidant Enzymes.

    Science.gov (United States)

    Zhong, Rong-Zhen; Fang, Yi; Qin, Gui-Xin; Li, Hao-Yang; Zhou, Dao-Wei

    2015-09-16

    To study the mechanisms of tea catechins (TCs) in goat muscles against oxidative stress, skeletal muscle cells (SMCs) induced by H2O2 or not were incubated with TCs or 3H-1,2-dithiole-3-thione (D3T) and were defined as H2O2, H2O2D3T, H2O2TC, D3T, and TC treatments, respectively. Results showed that, similar to effects of D3T, TCs regulated mRNA and protein expression of antioxidant enzymes by suppressing Keap1 protein expression in SMCs from 1.58 ± 0.12 to 0.71 ± 0.21 and 1.03 ± 0.11 in H2O2TC and TC groups, respectively; however, effects differed in oxidative condition of cells and among enzymes. In stressed cells, TCs increased catalase and glutathione S-transferases (GST) activities (P goats fed grain supplemented with TCs or D3T following infusion with H2O2 was conducted to further verify mechanisms of TC action. As seen in vitro, TCs reduced Keap1 protein expression (P goats under both conditions increased meat color and tenderness (P ≤ 0.001). In conclusion, TCs protected goat muscles against oxidative stress and subsequently improved meat quality by modulating phase 2 antioxidant enzymes and Keap1 expression. PMID:26118494

  15. Amelioration Effect of Zinc and Iron Supplementation on Selected Oxidative Stress Enzymes in Liver and Kidney of Cadmium-Treated Male Albino Rat.

    Science.gov (United States)

    Jamakala, Obaiah; Rani, Usha A

    2015-01-01

    Cadmium (Cd) is a highly toxic, nonessential heavy metal with many industrial uses that can contribute to a well-defined spectrum of diseases in animals as well as in humans. The present study examines the effect of zinc (Zn) and iron (Fe) supplementation on oxidative stress enzymes in Cd-treated rats. Wistar strain male albino rats were treated with cadmium chloride (CdCl2) at a dose of 1/10(th) LD50/48 h, that is, 22.5 mg/kg body weight for 7, 15, and 30 days (d) time intervals. The 15d Cd-treated rats were divided into three groups. The first group received Zn (12 mg/kg), second group Fe (40 mg/kg) alone, and third group supplemented with both Zn and Fe and observed for 7, 15, and 30d. After the specific time intervals, rats were decapitated and oxidative stress enzymes like catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) were assayed in liver and kidney. Simultaneously lipid peroxidation (LPO) levels were also measured. A significant elevation in LPO levels with decreased activity levels of CAT, SOD, GPx, and GST were observed during Cd intoxication. With Zn and/or Fe supplementation, a significant reversal in the oxidative stress enzymes was observed. Our study reveals that combination of Zn and Fe supplementation is effective in detoxifying the Cd body burden from the test tissues. PMID:26862254

  16. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 218, Revision 1 (FGE.218Rev1): alpha,beta-Unsaturated aldehydes and precursors from subgroup 4.2 of FGE.19: Furfural derivatives

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    .001], for which there was a request for genotoxicity data in FGE.218. Flavouring Group Evaluation 218 (FGE.218) consists of furfural [FL-no: 13.018] and seven substances structurally related to furfural, 5-methylfurfural [FL-no: 13.001], furfuryl alcohol [FL-no: 13.019] and five esters of furfuryl alcohol...... is expected to be oxidised to the alpha,beta-unsaturated aldehyde furfural. However, based on the data then available the Panel concluded that furfural is not of concern with respect to genotoxicity. Furthermore, the Panel concluded that not only furfural but also the structurally related furfuryl alcohol...... to 5-[(sulphoxy)methyl]furfural which shows genotoxic potential in vitro, 5-hydroxymethylfurfural could not be evaluated through the Procedure. Accordingly, the Panel concluded that 5-methylfurfural could not be evaluated through the Procedure either. Industry has submitted additional data on the 5...

  17. Possible involvement of membrane lipids peroxidation and oxidation of catalytically essential thiols of the cerebral transmembrane sodium pump as component mechanisms of iron-mediated oxidative stress-linked dysfunction of the pump's activity

    Directory of Open Access Journals (Sweden)

    T.I. Omotayo

    2015-04-01

    Full Text Available The precise molecular events defining the complex role of oxidative stress in the inactivation of the cerebral sodium pump in radical-induced neurodegenerative diseases is yet to be fully clarified and thus still open. Herein we investigated the modulation of the activity of the cerebral transmembrane electrogenic enzyme in Fe2+-mediated in vitro oxidative stress model. The results show that Fe2+ inhibited the transmembrane enzyme in a concentration dependent manner and this effect was accompanied by a biphasic generation of aldehydic product of lipid peroxidation. While dithiothreitol prevented both Fe2+ inhibitory effect on the pump and lipid peroxidation, vitamin E prevented only lipid peroxidation but not inhibition of the pump. Besides, malondialdehyde (MDA inhibited the pump by a mechanism not related to oxidation of its critical thiols. Apparently, the low activity of the pump in degenerative diseases mediated by Fe2+ may involve complex multi-component mechanisms which may partly involve an initial oxidation of the critical thiols of the enzyme directly mediated by Fe2+ and during severe progression of such diseases; aldehydic products of lipid peroxidation such as MDA may further exacerbate this inhibitory effect by a mechanism that is likely not related to the oxidation of the catalytically essential thiols of the ouabain-sensitive cerebral electrogenic pump.

  18. Reactivity of TEMPO anion as a nucleophile and its applications for selective transformations of haloalkanes or acyl halides to aldehydes

    OpenAIRE

    Inokuchi, Tsutomu; Kawafuchi, Hiroyuki

    2004-01-01

    Sodium 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO−Na+), generated by reduction of TEMPO· with sodium naphthalenide in THF, reacted with alkyl halides or acyl halides to produce O-alkylated or acylated TEMPOs, which were in turn oxidized with mCPBA or reduced with DIBAL-H to afford the corresponding aldehydes, thus accomplishing a new protocol for the halides-carbonyls conversion.

  19. Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

    Science.gov (United States)

    Jaja, S I; Ogungbemi, S O; Kehinde, M O; Anigbogu, C N

    2016-06-01

    The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (pconcentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects.

  20. Antioxidant enzymes and oxidative stress adaptation to exercise training: Comparison of endurance, resistance, and concurrent training in untrained males

    Directory of Open Access Journals (Sweden)

    Kamal Azizbeigi

    2014-06-01

    Full Text Available The aim of this study was to compare the effect of endurance training (ET, resistance training (RT, and concurrent training (CT on circulating antioxidant capacity and oxidative stress. For this purpose, 30 men aged 21.7 ± 2.4 years were assigned to the following three training groups: ET, which included continuous running with incremental intensity that was increased up to 80% of maximal heart rate (n = 10; RT, which included a beginning load of 50% of one repetition maximum (1RM that was increased up to 80% of 1RM (n = 10; and CT, which included ET and RT programs every other day during the week (n = 10. Activities of superoxide dismutase (SOD and glutathione peroxidase (GPx in erythrocytes and total antioxidant capacity (TAC and malondialdehyde (MDA level in plasma were measured. The results showed that SOD significantly increased by 21.85% (p = 0.020, 9.54% (p = 0.032, and 14.55% (p = 0.038 in the ET, RT, and CT groups, respectively. Furthermore, the activity of erythrocyte GPx significantly increased in the ET (p = 0.018 and CT (p = 0.042 groups. The TAC increased significantly in the ET (p = 0.040 and CT (p = 0.049 groups compared with the pretest values. The MDA level significantly decreased in the ET group by 32.7% (p = 0.028, by 32% in the RT group (p = 0.025, and by 29.1% (p = 0.047 in the CT group. However, there was no significant difference in the interaction of time and group between variables of SOD and GPx enzymes and TAC of plasma and MDA in the ET, RT, and CT groups (p < 0.05. It can be concluded that all three training types induced the same changes in redox state (increased SOD activity and reduction in MDA levels, but at different rates.

  1. Strictosidine-related enzymes involved in the alkaloid biosynthesis of Uncaria tomentosa root cultures grown under oxidative stress.

    Science.gov (United States)

    Vera-Reyes, Ileana; Huerta-Heredia, Ariana A; Ponce-Noyola, Teresa; Flores-Sanchez, Isvett Josefina; Esparza-García, Fernando; Cerda-García-Rojas, Carlos M; Trejo-Tapia, Gabriela; Ramos-Valdivia, Ana C

    2013-01-01

    The activity and gene expression of strictosidine-related enzymes in Uncaria tomentosa root cultures exposed to oxidative stress were studied. Elicitation with 0.2 mM hydrogen peroxide (H2 O2 ) or a combination of 0.8 mM buthionine sulfoximine and 0.2 mM jasmonic acid (BSO-JA) increased peroxidase activities by twofold at Day 8 and glutathione reductase by 1.4-fold at Day 5 in H2 O2 elicited cultures respect to the control. Production of monoterpenoid oxindole alkaloids (MOA), 3α-dihydrocadambine, and dolichantoside was stimulated after H2 O2 elicitation, reaching levels of 886.4 ± 23.6, 847.7 ± 25.4, and 87.5 ± 7.2 µg/g DW, at Day 8 which were 1.7-, 2.1-, and 2.3-fold higher relative to control. BSO-JA elicited cultures produced about twice alkaloids than H2 O2 -treated cultures, following a biphasic pattern with maxima at 0.5 and 8 days. Alkaloid production was preceded by increase in strictosidine synthase (STR) and strictosidine glucosidase (SGD) activities. After elicitation with H2 O2 or BSO-JA, the STR activity (pKat/mg protein) increased by 1.9-fold (93.8 ± 17.8 at 24 h) or 2.5-fold (102.4 ± 2.2 at 6 h) and the SGD activity (pKat/mg protein) by 2.8-fold (245.2 ± 14.4 at 6 h) or 4.2-fold (421.2 ± 1.8 at 18 h) relative to control. STR and SGD transcripts were upregulated after elicitation. H2 O2 -treated roots showed higher levels of STR at 48-192 h and SGD at 24-48 h, while BSO-JA treatments showed STR increased at 12 h and SGD at 24 h. Also, LC/ESI-MS confirmed the biosynthesis of dolichantoside from N-ω-methyltryptamine and secologanin by U. tomentosa protein extracts.

  2. Role of vitamin B6 status on antioxidant defenses, glutathione, and related enzyme activities in mice with homocysteine-induced oxidative stress

    Directory of Open Access Journals (Sweden)

    Cheng-Chin Hsu

    2015-04-01

    Full Text Available Background: Vitamin B6 may directly or indirectly play a role in oxidative stress and the antioxidant defense system. Objective: The purpose of this study was to examine the associations of vitamin B6 status with cysteine, glutathione, and its related enzyme activities in mice with homocysteine-induced oxidative stress. Design: Four-week-old male BALB/c mice were weighed and divided into one of four dietary treatment groups fed either a normal diet (as a control group and a homocysteine group, a vitamin B6-deficient diet (as a B6-deficient group, or a B6-supplemented diet (a pyridoxine-HCl-free diet supplemented with 14 mg/kg of pyridoxine-HCl, as a B6 supplement group for 28 days. Homocysteine thiolactone was then added to drinking water in three groups for 21 days to induce oxidative stress. At the end of the study, mice were sacrificed by decapitation and blood and liver samples were obtained. Results: Mice with vitamin B6-deficient diet had the highest homocysteine concentration in plasma and liver among groups. Significantly increased hepatic malondialdehyde levels were observed in the vitamin B6-deficient group. Among homocysteine-treated groups, mice with vitamin B6-deficient diet had the highest plasma glutathione concentration and relatively lower hepatic glutathione concentration. The glutathione peroxidase activities remained relatively stable in plasma and liver whether vitamin B6 was adequate, deficient, or supplemented. Conclusions: Mice with deficient vitamin B6 intakes had an aggravate effect under homocysteine-induced oxidative stress. The vitamin B6-deficient status seems to mediate the oxidative stress in connection with the redistribution of glutathione from liver to plasma, but not further affect glutathione-related enzyme activities in mice with homocysteine-induced oxidative stress.

  3. ‘Dopamine-first’ mechanism enables the rational engineering of the norcoclaurine synthase aldehyde activity profile

    Science.gov (United States)

    Lichman, Benjamin R; Gershater, Markus C; Lamming, Eleanor D; Pesnot, Thomas; Sula, Altin; Keep, Nicholas H; Hailes, Helen C; Ward, John M

    2015-01-01

    Norcoclaurine synthase (NCS) (EC 4.2.1.78) catalyzes the Pictet–Spengler condensation of dopamine and an aldehyde, forming a substituted (S)-tetrahydroisoquinoline, a pharmaceutically important moiety. This unique activity has led to NCS being used for both in vitro biocatalysis and in vivo recombinant metabolism. Future engineering of NCS activity to enable the synthesis of diverse tetrahydroisoquinolines is dependent on an understanding of the NCS mechanism and kinetics. We assess two proposed mechanisms for NCS activity: (a) one based on the holo X-ray crystal structure and (b) the ‘dopamine-first’ mechanism based on computational docking. Thalictrum flavum NCS variant activities support the dopamine-first mechanism. Suppression of the non-enzymatic background reaction reveals novel kinetic parameters for NCS, showing it to act with low catalytic efficiency. This kinetic behaviour can account for the ineffectiveness of recombinant NCS in in vivo systems, and also suggests NCS may have an in planta role as a metabolic gatekeeper. The amino acid substitution L76A, situated in the proposed aldehyde binding site, results in the alteration of the enzyme's aldehyde activity profile. This both verifies the dopamine-first mechanism and demonstrates the potential for the rational engineering of NCS activity. PMID:25620686

  4. 'Dopamine-first' mechanism enables the rational engineering of the norcoclaurine synthase aldehyde activity profile.

    Science.gov (United States)

    Lichman, Benjamin R; Gershater, Markus C; Lamming, Eleanor D; Pesnot, Thomas; Sula, Altin; Keep, Nicholas H; Hailes, Helen C; Ward, John M

    2015-03-01

    Norcoclaurine synthase (NCS) (EC 4.2.1.78) catalyzes the Pictet-Spengler condensation of dopamine and an aldehyde, forming a substituted (S)-tetrahydroisoquinoline, a pharmaceutically important moiety. This unique activity has led to NCS being used for both in vitro biocatalysis and in vivo recombinant metabolism. Future engineering of NCS activity to enable the synthesis of diverse tetrahydroisoquinolines is dependent on an understanding of the NCS mechanism and kinetics. We assess two proposed mechanisms for NCS activity: (a) one based on the holo X-ray crystal structure and (b) the 'dopamine-first' mechanism based on computational docking. Thalictrum flavum NCS variant activities support the dopamine-first mechanism. Suppression of the non-enzymatic background reaction reveals novel kinetic parameters for NCS, showing it to act with low catalytic efficiency. This kinetic behaviour can account for the ineffectiveness of recombinant NCS in in vivo systems, and also suggests NCS may have an in planta role as a metabolic gatekeeper. The amino acid substitution L76A, situated in the proposed aldehyde binding site, results in the alteration of the enzyme's aldehyde activity profile. This both verifies the dopamine-first mechanism and demonstrates the potential for the rational engineering of NCS activity. PMID:25620686

  5. Bioavailability of catechins from guaraná (Paullinia cupana) and its effect on antioxidant enzymes and other oxidative stress markers in healthy human subjects.

    Science.gov (United States)

    Yonekura, Lina; Martins, Carolina Aguiar; Sampaio, Geni Rodrigues; Monteiro, Marcela Piedade; César, Luiz Antônio Machado; Mioto, Bruno Mahler; Mori, Clara Satsuki; Mendes, Thaíse Maria Nogueira; Ribeiro, Marcelo Lima; Arçari, Demetrius Paiva; Torres, Elizabeth Aparecida Ferraz da Silva

    2016-07-13

    We assessed the effects of guaraná (Paullinia cupana) consumption on plasma catechins, erythrocyte antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase) and biomarkers of oxidative stress (ex vivo LDL oxidation, plasma total antioxidant status and ORAC, and lymphocyte single cell gel electrophoresis) in healthy overweight subjects. Twelve participants completed a 15-day run-in period followed by a 15-day intervention with a daily intake of 3 g guaraná seed powder containing 90 mg (+)-catechin and 60 mg (-)-epicatechin. Blood samples were taken on the first and last day of the intervention period, fasting and 1 h post-dose. The administration of guaraná increased plasma ORAC, while reducing ex vivo LDL oxidation (only in the first study day) and hydrogen peroxide-induced DNA damage in lymphocytes, at 1 h post-dose. Plasma catechin (0.38 ± 0.12 and 0.44 ± 0.18 nmol mL(-1)), epicatechin (0.59 ± 0.18 and 0.64 ± 0.25 nmol mL(-1)) and their methylated metabolites were observed at 1 h post-dose but were almost negligible after overnight fasting. The activities of catalase (in both study days) and glutathione peroxidase (in the last intervention day) increased at 1 h post-dose. Furthermore, the activity of both enzymes remained higher than the basal levels in overnight-fasting individuals on the last intervention day, suggesting a prolonged effect of guaraná that continues even after plasma catechin clearance. In conclusion, guaraná catechins are bioavailable and contribute to reduce the oxidative stress of clinically healthy individuals, by direct antioxidant action of the absorbed phytochemicals and up-regulation of antioxidant/detoxifying enzymes. PMID:27302304

  6. Purification, molecular cloning, and expression of 2-hydroxyphytanoyl- CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon-carbon bond cleavage during à-oxidation of 3- methyl-branched fatty acids

    CERN Document Server

    Foulon, V; Croes, K; Waelkens, E

    1999-01-01

    Purification, molecular cloning, and expression of 2-hydroxyphytanoyl- CoA lyase, a peroxisomal thiamine pyrophosphate-dependent enzyme that catalyzes the carbon-carbon bond cleavage during à-oxidation of 3- methyl-branched fatty acids

  7. Metabolite Profile Resulting from the Activation/Inactivation of 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 2-Methyltetrahydro-β-carboline by Oxidative Enzymes

    Directory of Open Access Journals (Sweden)

    Tomás Herraiz

    2013-01-01

    Full Text Available Metabolic enzymes are involved in the activation/deactivation of the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyiridine (MPTP neurotoxin and its naturally occurring analogs 2-methyltetrahydro-β-carbolines. The metabolic profile and biotransformation of these protoxins by three enzymes, monoamine oxidase (MAO, cytochrome P450, and heme peroxidases (myeloperoxidase and lactoperoxidase, were investigated and compared. The metabolite profile differed among the enzymes investigated. MAO and heme peroxidases activated these substances to toxic pyridinium and β-carbolinium species. MAO catalyzed the oxidation of MPTP to 1-methyl-4-phenyl-2,3-dihydropyridinium cation (MPDP+, whereas heme peroxidases catalyzed the oxidation of MPDP+ to 1-methyl-4-phenylpyridinium (MPP+ and of 2-methyltetrahydro-β-carboline to 2-methyl-3,4-dihydro-β-carbolinium cation (2-Me-3,4-DHβC+. These substances were inactivated by cytochrome P450 2D6 through N-demethylation and aromatic hydroxylation (MPTP and aromatic hydroxylation (2-methyltetrahydro-β-carboline. In conclusion, the toxicological effects of these protoxins might result from a balance between the rate of their activation to toxic products (i.e., N-methylpyridinium-MPP+ and MPDP+- and N-methyl-β-carbolinium—βC+— by MAO and heme peroxidases and the rate of inactivation (i.e., N-demethylation, aromatic hydroxylation by cytochrome P450 2D6.

  8. Computational study of recognition of DNA damages and their repair. 8-oxoguanine oxidative DNA damage with repair enzyme hOGG1

    International Nuclear Information System (INIS)

    The molecular dynamics (MD) simulations of DNA mutagenic oxidative lesion - 7,8-dihydro-8-oxoguanine (8-oxoG), single and complexed with the repair enzyme - human oxoguanine glycosylase 1 (hOGG1) were performed for 1 nanosecond (ns) in order to determine structural changes at the DNA molecule and to describe a dynamical process of DNA-enzyme complex formation. The molecule of 8-oxoG was inserted into central part of B-DNA 15-mer d(GCGTCCA'8-oxoG'GTCTACC)2 replacing the native guanine 8. In the case of simulation of single DNA molecule the broken hydrogen bonds resulting in locally collapsed B-DNA structure were observed at the lesion site. In addition the adenine on the complementary strand (separated from 8-oxoG by 1 base pair) was flipped-out of the DNA double helix. In the case of simulation of DNA and repair enzyme hOGG1, the DNA-enzyme complex was formed after 500 picoseconds of MD that lasted stable until the simulation was terminated at 1 ns. The complex was represented by the overlapping Van der Waals surfaces of DNA and enzyme molecules. The N-terminus of arginine 324 was located close to the phosphodiester bond of nucleotide with 8-oxoG enabling chemical reactions between amino acid and lesion. Phosphodiester bond at C5' of 8-oxoG was at the position close to the N-terminus of arginine 324. The water mediated hydrogen bonds network was formed in each contact area between DNA and enzyme further enhancing the stability of complex. In the background simulation of the identical molecular system with the native DNA, neither the complex nor the water mediated hydrogen bond network were observed. (author)

  9. Responses of soil hydrolytic enzymes, ammonia-oxidizing bacteria and archaea to nitrogen applications in a temperate grassland in Inner Mongolia.

    Science.gov (United States)

    Zhang, Xinyu; Tang, Yuqian; Shi, Yao; He, Nianpeng; Wen, Xuefa; Yu, Qiang; Zheng, Chunyu; Sun, Xiaomin; Qiu, Weiwen

    2016-01-01

    We used a seven-year urea gradient applied field experiment to investigate the effects of nitrogen (N) applications on soil N hydrolytic enzyme activity and ammonia-oxidizing microbial abundance in a typical steppe ecosystem in Inner Mongolia. The results showed that N additions inhibited the soil N-related hydrolytic enzyme activities, especially in 392 kg N ha(-1 )yr(-1) treatment. As N additions increased, the amoA gene copy ratios of ammonia-oxidizing archaea (AOA) to ammonia-oxidizing bacteria (AOB) decreased from 1.13 to 0.65. Pearson correlation analysis showed that the AOA gene copies were negatively related with NH4(+)-N content. However, the AOB gene copies were positively correlated with NO3(-)-N content. Moderate N application rates (56-224 kg N ha(-1 )yr(-1)) accompanied by P additions are beneficial to maintaining the abundance of AOB, as opposed to the inhibition of highest N application rate (392 kg N ha(-1 )yr(-1)) on the abundance of AOB. This study suggests that the abundance of AOB and AOA would not decrease unless N applications exceed 224 kg N ha(-1 )yr(-1) in temperate grasslands in Inner Mongolia. PMID:27596731

  10. Thiamine increases the resistance of baker's yeast Saccharomyces cerevisiae against oxidative, osmotic and thermal stress, through mechanisms partly independent of thiamine diphosphate-bound enzymes.

    Science.gov (United States)

    Wolak, Natalia; Kowalska, Ewa; Kozik, Andrzej; Rapala-Kozik, Maria

    2014-12-01

    Numerous recent studies have established a hypothesis that thiamine (vitamin B1 ) is involved in the responses of different organisms against stress, also suggesting that underlying mechanisms are not limited to the universal role of thiamine diphosphate (TDP) in the central cellular metabolism. The current work aimed at characterising the effect of exogenously added thiamine on the response of baker's yeast Saccharomyces cerevisiae to the oxidative (1 mM H2 O2 ), osmotic (1 M sorbitol) and thermal (42 °C) stress. As compared to the yeast culture in thiamine-free medium, in the presence of 1.4 μM external thiamine, (1) the relative mRNA levels of major TDP-dependent enzymes under stress conditions vs. unstressed control (the 'stress/control ratio') were moderately lower, (2) the stress/control ratio was strongly decreased for the transcript levels of several stress markers localised to the cytoplasm, peroxisomes, the cell wall and (with the strongest effect observed) the mitochondria (e.g. Mn-superoxide dismutase), (3) the production of reactive oxygen and nitrogen species under stress conditions was markedly decreased, with the significant alleviation of concomitant protein oxidation. The results obtained suggest the involvement of thiamine in the maintenance of redox balance in yeast cells under oxidative stress conditions, partly independent of the functions of TDP-dependent enzymes.

  11. Enzymes involved in the anaerobic oxidation of n-alkanes: from methane to long-chain paraffins

    OpenAIRE

    Amy V. Callaghan

    2013-01-01

    Anaerobic microorganisms play key roles in the biogeochemical cycling of methane and non-methane alkanes. To date, there appear to be at least three proposed mechanisms of anaerobic methane oxidation (AOM). The first pathway is mediated by consortia of archaeal anaerobic methane oxidizers and sulfate-reducing bacteria via ‘reverse methanogenesis’ and is catalyzed by a homologue of methyl-coenzyme M reductase. The second pathway is also mediated by anaerobic methane oxidizers and sulfate-red...

  12. Nitro-Oleic Acid Reduces J774A.1 Macrophage Oxidative Status and Triglyceride Mass: Involvement of Paraoxonase2 and Triglyceride Metabolizing Enzymes.

    Science.gov (United States)

    Rosenblat, Mira; Rom, Oren; Volkova, Nina; Aviram, Michael

    2016-08-01

    Nitro-fatty acids possess anti-atherogenic properties, but their effects on macrophage oxidative status and lipid metabolism that play important roles in atherosclerosis development are unclear. This study compared the effects of nitro-oleic acid (OLA-NO2) with those of native oleic acid (OLA) on intracellular reactive oxygen species (ROS) generation, anti-oxidants and metabolism of triglycerides and cholesterol in J774A.1 macrophages. Upon incubating the cells with physiological concentrations of OLA-NO2 (0-1 µM) or with equivalent levels of OLA, ROS levels measured by 2, 7-dichlorofluorescein diacetate, decreased dose-dependently, but the anti-oxidative effects of OLA-NO2 were significantly augmented. Copper ion addition increased ROS generation in OLA treated macrophages without affecting OLA-NO2 treated cells. These effects could be attributed to elevated glutathione levels and to increased activity and expression of paraoxonase2 that were observed in OLA-NO2 vs OLA treated cells. Beneficial effects on triglyceride metabolism were noted in OLA-NO2 vs OLA treated macrophages in which cellular triglycerides were reduced due to attenuated biosynthesis and accelerated hydrolysis of triglycerides. Accordingly, OLA-NO2 treated cells demonstrated down-regulation of diacylglycerol acyltransferase1, the key enzyme in triglyceride biosynthesis, and increased expression of hormone-sensitive lipase and adipose triglyceride lipase that regulate triglyceride hydrolysis. Finally, OLA-NO2 vs OLA treatment resulted in modest but significant beneficial effects on macrophage cholesterol metabolism, reducing cholesterol biosynthesis rate and low density lipoprotein influx into the cells, while increasing high density lipoprotein-mediated cholesterol efflux from the macrophages. Collectively, compared with OLA, OLA-NO2 modestly but significantly reduces macrophage oxidative status and cellular triglyceride content via modulation of cellular anti-oxidants and triglyceride

  13. Nitro-Oleic Acid Reduces J774A.1 Macrophage Oxidative Status and Triglyceride Mass: Involvement of Paraoxonase2 and Triglyceride Metabolizing Enzymes.

    Science.gov (United States)

    Rosenblat, Mira; Rom, Oren; Volkova, Nina; Aviram, Michael

    2016-08-01

    Nitro-fatty acids possess anti-atherogenic properties, but their effects on macrophage oxidative status and lipid metabolism that play important roles in atherosclerosis development are unclear. This study compared the effects of nitro-oleic acid (OLA-NO2) with those of native oleic acid (OLA) on intracellular reactive oxygen species (ROS) generation, anti-oxidants and metabolism of triglycerides and cholesterol in J774A.1 macrophages. Upon incubating the cells with physiological concentrations of OLA-NO2 (0-1 µM) or with equivalent levels of OLA, ROS levels measured by 2, 7-dichlorofluorescein diacetate, decreased dose-dependently, but the anti-oxidative effects of OLA-NO2 were significantly augmented. Copper ion addition increased ROS generation in OLA treated macrophages without affecting OLA-NO2 treated cells. These effects could be attributed to elevated glutathione levels and to increased activity and expression of paraoxonase2 that were observed in OLA-NO2 vs OLA treated cells. Beneficial effects on triglyceride metabolism were noted in OLA-NO2 vs OLA treated macrophages in which cellular triglycerides were reduced due to attenuated biosynthesis and accelerated hydrolysis of triglycerides. Accordingly, OLA-NO2 treated cells demonstrated down-regulation of diacylglycerol acyltransferase1, the key enzyme in triglyceride biosynthesis, and increased expression of hormone-sensitive lipase and adipose triglyceride lipase that regulate triglyceride hydrolysis. Finally, OLA-NO2 vs OLA treatment resulted in modest but significant beneficial effects on macrophage cholesterol metabolism, reducing cholesterol biosynthesis rate and low density lipoprotein influx into the cells, while increasing high density lipoprotein-mediated cholesterol efflux from the macrophages. Collectively, compared with OLA, OLA-NO2 modestly but significantly reduces macrophage oxidative status and cellular triglyceride content via modulation of cellular anti-oxidants and triglyceride

  14. The Radical S-Adenosyl-l-methionine Enzyme MftC Catalyzes an Oxidative Decarboxylation of the C-Terminus of the MftA Peptide.

    Science.gov (United States)

    Bruender, Nathan A; Bandarian, Vahe

    2016-05-24

    Ribosomally synthesized post-translationally modified peptides (RiPPs) are encoded in the genomes of a wide variety of microorganisms, in the proximity of open reading frames that encode enzymes that conduct extensive modifications, many of which are novel. Recently, members of the radical S-adenosyl-l-methionine (SAM) superfamily have been identified in these biosynthetic clusters. Herein, we demonstrate the putative radical SAM enzyme, MftC, oxidatively decarboxylates the C-terminus of the MftA peptide in the presence of the accessory protein MftB. The reaction catalyzed by MftC expands the repertoire of peptide-based radical SAM chemistry beyond the intramolecular cross-links. PMID:27158836

  15. Androgen regulation of aldehyde dehydrogenase 1A3 (ALDH1A3) in androgen responsive human prostate cancer cell LNCaP.

    Science.gov (United States)

    Previous gene array data from our laboratory identified the retinoic acid (RA) biosynthesis enzyme aldehyde dehydrogenase 1A3 (ALDH1A3) as a putative androgen-responsive gene in prostate cancer epithelial cells (LNCaP). In the present study we attempted to identify if any of the three ALDH1A/RA synt...

  16. Evaluation of 3-hydroxybutyrate as an enzyme-protective agent against heating and oxidative damage and its potential role in stress response of poly(3-hydroxybutyrate) accumulating cells.

    Science.gov (United States)

    Obruca, Stanislav; Sedlacek, Petr; Mravec, Filip; Samek, Ota; Marova, Ivana

    2016-02-01

    Poly(3-hydroxybutyrate) (PHB) is a common carbon- and energy-storage compound simultaneously produced and degraded into its monomer 3-hydroxybutyrate (3HB) by numerous bacteria and Archae in a metabolic pathway called the PHB cycle. We investigated 3HB as a chemical chaperone capable of protecting model enzymes, namely lipase and lysozyme, from adverse effects of high temperature and oxidation. Heat-mediated denaturation of lipase in the presence or absence of 3HB was monitored by dynamic light scattering (DLS) revealing a significant protective effect of 3HB which increased as its concentration rose. Furthermore, when compared at the same molar concentration, 3HB showed a greater protective effect than the well-known chemical chaperones trehalose and hydroxyectoine. The higher protective effect of 3HB was also confirmed when employing differential scanning calorimetry (DSC) and lysozyme as a model enzyme. Furthermore, 3HB was capable of protecting lipase not only against thermal-mediated denaturation but also against oxidative damage by Cu(2+) and H2O2; its protection was higher than that of trehalose and comparable to that of hydroxyectoine. Taking into account that the PHB-producing strain Cupriavidus necator H16 reveals a 16.5-fold higher intracellular concentration than the PHB non-producing mutant C. necator PHB(-4), it might be expected that the functional PHB cycle might be responsible for maintaining a higher intracellular level of 3HB which, aside from other positive aspects of functional PHB metabolism, enhances stress resistance of bacterial strains capable of simultaneous PHB synthesis and mobilization. In addition, 3HB can be used in various applications and formulations as an efficient enzyme-stabilizing and enzyme-protecting additive. PMID:26590589

  17. Improving the direct electron transfer in monolithic bioelectrodes prepared by immobilization of FDH enzyme on carbon-coated anodic aluminum oxide films

    Directory of Open Access Journals (Sweden)

    Alberto eCastro-Muñiz

    2016-02-01

    Full Text Available The present work reports the preparation of binderless carbon-coated porous films and the study of their performance as monolithic bioanodes. The films were prepared by coating anodic aluminum oxide (AAO films with a thin layer of nitrogen-doped carbon by chemical vapor deposition. The films have cylindrical straight pores with controllable diameter and length. These monolithic films were used directly as bioelectrodes by loading the films with D-fructose dehydrogenase (FDH, an oxidoreductase enzyme that catalyzes the oxidation of D-fructose to 5-keto-D-fructose. The immobilization of the enzymes was carried out by physical adsorption in liquid phase and with an electrostatic attraction method. The latter method takes advantage of the fact that FDH is negatively charged during the catalytic oxidation of fructose. Thus the immobilization was performed under the application of a positive voltage to the CAAO film in a FDH-fructose solution in McIlvaine buffer (pH 5 at 25 ºC. As a result, the FDH modified electrodes with the latter method show much better electrochemical response than that with the conventional physical adsorption method. Due to the singular porous structure of the monolithic films, which consists of an array of straight and parallel nanochannels, it is possible to rule out the effect of the diffusion of the D-fructose into the pores. Thus the improvement in the performance upon using the electrostatic attraction method can be ascribed not only to a higher uptake, but also to a more appropriate molecule orientation of the enzyme units on the surface of the electrodes.

  18. Improving the direct electron transfer in monolithic bioelectrodes prepared by immobilization of FDH enzyme on carbon-coated anodic aluminum oxide films

    Science.gov (United States)

    Castro-Muñiz, Alberto; Hoshikawa, Yasuto; Komiyama, Hiroshi; Nakayama, Wataru; Itoh, Tetsuji; Kyotani, Takashi

    2016-02-01

    The present work reports the preparation of binderless carbon-coated porous films and the study of their performance as monolithic bioanodes. The films were prepared by coating anodic aluminum oxide (AAO) films with a thin layer of nitrogen-doped carbon by chemical vapor deposition. The films have cylindrical straight pores with controllable diameter and length. These monolithic films were used directly as bioelectrodes by loading the films with D-fructose dehydrogenase (FDH), an oxidoreductase enzyme that catalyzes the oxidation of D-fructose to 5-keto-D-fructose. The immobilization of the enzymes was carried out by physical adsorption in liquid phase and with an electrostatic attraction method. The latter method takes advantage of the fact that FDH is negatively charged during the catalytic oxidation of fructose. Thus the immobilization was performed under the application of a positive voltage to the CAAO film in a FDH-fructose solution in McIlvaine buffer (pH 5) at 25 ºC. As a result, the FDH modified electrodes with the latter method show much better electrochemical response than that with the conventional physical adsorption method. Due to the singular porous structure of the monolithic films, which consists of an array of straight and parallel nanochannels, it is possible to rule out the effect of the diffusion of the D-fructose into the pores. Thus the improvement in the performance upon using the electrostatic attraction method can be ascribed not only to a higher uptake, but also to a more appropriate molecule orientation of the enzyme units on the surface of the electrodes.

  19. 植物酵素对茄子苹果抗氧化能力研究%The Research of Plant Enzymes Oxidation Resistance on Eggplants and Apples

    Institute of Scientific and Technical Information of China (English)

    沈孝霖

    2016-01-01

    抗氧化是延长蔬果贮藏时间的重要手段,传统的普通防腐剂对于人体存在危害.通过考察植物酵素、防腐剂、空白试样三种试样对茄子、苹果的失重率、褐变度、维生素C的含量和腐烂速度的影响,研究了植物酵素对于蔬果防腐的效果.通过称重、分光光度法得出相应的实验数据作为评价标准.实验结果得出,植物酵素可以有效减小植物的失重率、褐变度,并使植物腐烂速度变缓,对于维持维生素C含量无影响,具有一定的抗氧化能力,满足作为绿色防腐剂开发的基本要求.%Anti-oxidation is the key way to prolong storage time of vegetables and fruits, but normal preservative has negative effect on human's health. To study plant enzymes' oxidation resistance on vegetables and fruits, three groups of check test using plant enzymes,preservative and blank control were done. The check tests were designed to observe the plant enzymes' effect on vegetables and fruits'weight loss,degree of browning,Vitamin C content and rate of de-cay. Experimental data from weighing and spectrophotometry was used as evaluation criterion. Through the analysis of the experimental data,it can be concluded that plant enzymes are useful in decreasing weight loss,degree of browning and rate of decay, no effect been found in holding Vitamin C content. In conclusion, plant enzymes' oxidation resis-tance can be proved,the requirements of developing green preservative are met.

  20. Green tea extract protects against nonalcoholic steatohepatitis in ob/ob mice by decreasing oxidative and nitrative stress responses induced by proinflammatory enzymes.

    Science.gov (United States)

    Chung, Min-Yu; Park, Hea Jin; Manautou, Jose E; Koo, Sung I; Bruno, Richard S

    2012-04-01

    Oxidative and nitrative stress responses resulting from inflammation exacerbate liver injury associated with nonalcoholic steatohepatitis (NASH) by inducing lipid peroxidation and protein nitration. The objective of this study was to investigate whether the anti-inflammatory properties of green tea extract (GTE) would protect against NASH by suppressing oxidative and nitrative damage mediated by proinflammatory enzymes. Obese mice (ob/ob) and their 5-week-old C57BL6 lean littermates were fed 0%, 0.5% or 1% GTE for 6 weeks (n=12-13 mice/group). In obese mice, hepatic lipid accumulation, inflammatory infiltrates and serum alanine aminotransferase activity were markedly increased, whereas these markers of hepatic steatosis, inflammation and injury were significantly reduced among obese mice fed GTE. GTE also normalized hepatic 4-hydroxynonenal and 3-nitro-tyrosine (N-Tyr) concentrations to those observed in lean controls. These oxidative and nitrative damage markers were correlated with alanine aminotransferase (P<.05; r=0.410-0.471). Improvements in oxidative and nitrative damage by GTE were also associated with lower hepatic nicotinamide adenine dinucleotide phosphate oxidase activity. Likewise, GTE reduced protein expression levels of hepatic myeloperoxidase and inducible nitric oxide synthase and decreased the concentrations of nitric oxide metabolites. Correlative relationships between nicotinamide adenine dinucleotide phosphate oxidase and hepatic 4-hydroxynonenal (r=0.364) as well as nitric oxide metabolites and N-Tyr (r=0.598) suggest that GTE mitigates lipid peroxidation and protein nitration by suppressing the generation of reactive oxygen and nitrogen species. Further study is warranted to determine whether GTE can be recommended as an effective dietary strategy to reduce the risk of obesity-triggered NASH. PMID:21543212

  1. Amelioration Effect of Zinc and Iron Supplementation on Selected Oxidative Stress Enzymes in Liver and Kidney of Cadmium-Treated Male Albino Rat

    OpenAIRE

    Jamakala, Obaiah; Rani, Usha A.

    2015-01-01

    Cadmium (Cd) is a highly toxic, nonessential heavy metal with many industrial uses that can contribute to a well-defined spectrum of diseases in animals as well as in humans. The present study examines the effect of zinc (Zn) and iron (Fe) supplementation on oxidative stress enzymes in Cd-treated rats. Wistar strain male albino rats were treated with cadmium chloride (CdCl2) at a dose of 1/10th LD50/48 h, that is, 22.5 mg/kg body weight for 7, 15, and 30 days (d) time intervals. The 15d Cd-tr...

  2. Evaluation of Various Packaging Systems on the Activity of Antioxidant Enzyme, and Oxidation and Color Stabilities in Sliced Hanwoo (Korean Cattle) Beef Loin during Chill Storage

    OpenAIRE

    Kang, Sun Moon; Kang, Geunho; Seong, Pil-Nam; Park, Beomyoung; Cho, Soohyun

    2014-01-01

    The effects of various packaging systems, vacuum packaging (VACP), medium oxygen-modified atmosphere packaging (50% O2/20% CO2/30% N2, MOMAP), MOMAP combined with vacuum skin packaging (VSP-MOMAP), high oxygen-MAP (80% O2/20% CO2/0% N2, HOMAP), and HOMAP combined with VSP (VSP-HOMAP), on the activity of antioxidant enzyme, and oxidation and color stabilities in sliced Hanwoo (Korean cattle) beef loin were investigated at 4°C for 14 d. Higher (p

  3. Mild and efficient strategy for site-selective aldehyde modification of glycosaminoglycans: tailoring hydrogels with tunable release of growth factor.

    Science.gov (United States)

    Wang, Shujiang; Oommen, Oommen P; Yan, Hongji; Varghese, Oommen P

    2013-07-01

    Aldehydes have been used as an important bioorthogonal chemical reporter for conjugation of large polymers and bioactive substances. However, generating aldehyde functionality on carbohydrate-based biopolymers without changing its native chemical structure has always persisted as a challenging task. The common methods employed to achieve this require harsh reaction conditions, which often compromise the structural integrity and biological function of these sensitive molecules. Here we report a mild and simple method to graft aldehydes groups on glycosaminoglycans (GAGs) in a site-selective manner without compromising the structural integrity of the biopolymer. This regio-selective modification was achieved by conjugating the amino-glycerol moiety on the carboxylate residue of the polymer, which allowed selective cleavage of pendent diol groups without interfering with the C2-C3 diol groups of the native glucopyranose residue. Kinetic evaluation of this reaction demonstrated significant differences in second-order reaction rate for periodate oxidation (by four-orders of magnitude) between the two types of vicinal diols. We employed this chemistry to develop aldehyde modifications of sulfated and nonsulfated GAGs such as hyaluronic acid (HA), heparin (HP), and chondroitin sulfate (CS). We further utilized these aldehyde grafted GAGs to tailor extracellular matrix mimetic injectable hydrogels and evaluated its rheological properties. The composition of the hydrogels was also found to modulate release of therapeutic protein such as FGF-2, demonstrating controlled release (60%) for over 14 days. In short, our result clearly demonstrates a versatile strategy to graft aldehyde groups on sensitive biopolymers under mild conditions that could be applied for various bioconjugation and biomedical applications such as drug delivery and regenerative medicine.

  4. Wiring of Glucose Oxidizing Flavin Adenine Dinucleotide-Dependent Enzymes by Methylene Blue-Modified Third Generation Poly(amidoamine) Dendrimers Attached to Spectroscopic Graphite Electrodes

    DEFF Research Database (Denmark)

    Castaing, Victor; Álvarez-Martos, Isabel; Ferapontova, Elena

    2016-01-01

    ordered multiple redox centers, represent an advanced alternative to the existing approaches. Here we show that methylene blue (MB)-labeled G3 PAMAM dendrimers covalently attached to the high-surface area spectroscopic graphite (Gr) electrodes form stable and spatially resolved electronic wires......, characterized by the heterogeneous ET rate constant of 7.1 0.1 s1; they can be used for electronic wiring of glucose-oxidizing FAD-containing enzymes, such as hexose oxidase (HOX), and further bioelectrocatalysis of glucose oxidation, starting, at pH 7, from -100 mV vs. Ag/AgCl. Thus, dendrimer......-templated electronic wires, comprising MB molecules conjugated to the periphery of the PAMAM and anchored to the surface of cost-effective Gr electrodes represent an efficient and robust tool for protein wiring to electrodes for their perspective bioelectronic applications in biosensors and biofuel cells....

  5. Efficient Synthesis of 2-Amino-6-Arylbenzothiazoles via Pd(0 Suzuki Cross Coupling Reactions: Potent Urease Enzyme Inhibition and Nitric Oxide Scavenging Activities of the Products

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2013-07-01

    Full Text Available In general, benzothiazole derivatives have attracted great interest due to thier pharmaceutical and biological importance. New 2-amino-6-arylbenzothiazoles were synthesized in moderate to excellent yields via Suzuki cross coupling reactions using various aryl boronic acids and aryl boronic acid pinacol esters and the antiurease and nitric oxide (NO scavenging activity of the products were also examined. The most active compound concerning urease enzyme inhibition was 6-phenylbenzo[d]thiazole-2-amine 3e, with an IC50 value of 26.35 µg/mL. Compound 3c, 6-(4-methoxyphenyl benzo[d]thiazole-2-amine, exhibited the highest nitric oxide percentage scavenging at 100µg/mL.

  6. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD+-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  7. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Tomofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135 (Japan); Ichinose, Hirofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Wariishi, Hiroyuki, E-mail: hirowari@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Innovation Center for Medical Redox Navigation, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

    2010-04-09

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  8. Effects of cerium oxide supplementation to laying hen diets on performance, egg quality, some antioxidant enzymes in serum and lipid oxidation in egg yolk.

    Science.gov (United States)

    Bölükbaşı, S C; Al-Sagan, A A; Ürüşan, H; Erhan, M K; Durmuş, O; Kurt, N

    2016-08-01

    This study was conducted to determine the effects of dietary cerium oxide levels (0, 100, 200, 300 or 400 mg/kg) on the laying performance, egg quality, some blood serum parameters and egg lipid peroxidation of laying hen. In total, one hundred and twenty 22-week-old brown Lohman LSL laying hens were randomly assigned to five groups equally (n = 24). Each treatment was replicated six times. Dietary supplementation of cerium oxide had no significant effect on feed intake and egg weight. The addition of cerium oxide to the laying hens' feed improved feed conversion ratio and increased (p laying hens feed led to a significant (p hen diets. It was also observed that serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration decreased significantly with supplementation of cerium oxide in diets. Inclusion of cerium oxide resulted in a significant reduction in thiobarbituric acid reactive substance (TBARS) values in egg yolk in this study. It can be concluded that the addition of cerium oxide had positive effects on egg production, feed conversion ratio and egg shelf life. Based on the results of this study, it could be advised to supplement laying hens feed with cerium oxide as feed additives. PMID:26847677

  9. Distributive Processing by the Iron(II)/α-Ketoglutarate-Dependent Catalytic Domains of the TET Enzymes Is Consistent with Epigenetic Roles for Oxidized 5-Methylcytosine Bases.

    Science.gov (United States)

    Tamanaha, Esta; Guan, Shengxi; Marks, Katherine; Saleh, Lana

    2016-08-01

    The ten-eleven translocation (TET) proteins catalyze oxidation of 5-methylcytosine ((5m)C) residues in nucleic acids to 5-hydroxymethylcytosine ((5hm)C), 5-formylcytosine ((5f)C), and 5-carboxycytosine ((5ca)C). These nucleotide bases have been implicated as intermediates on the path to active demethylation, but recent reports have suggested that they might have specific regulatory roles in their own right. In this study, we present kinetic evidence showing that the catalytic domains (CDs) of TET2 and TET1 from mouse and their homologue from Naegleria gruberi, the full-length protein NgTET1, are distributive in both chemical and physical senses, as they carry out successive oxidations of a single (5m)C and multiple (5m)C residues along a polymethylated DNA substrate. We present data showing that the enzyme neither retains (5hm)C/(5f)C intermediates of preceding oxidations nor slides along a DNA substrate (without releasing it) to process an adjacent (5m)C residue. These findings contradict a recent report by Crawford et al. ( J. Am. Chem. Soc. 2016 , 138 , 730 ) claiming that oxidation of (5m)C by CD of mouse TET2 is chemically processive (iterative). We further elaborate that this distributive mechanism is maintained for TETs in two evolutionarily distant homologues and posit that this mode of function allows the introduction of (5m)C forms as epigenetic markers along the DNA. PMID:27362828

  10. Supplementation with l-arginine stabilizes plasma arginine and nitric oxide metabolites, suppresses elevated liver enzymes and peroxidation in sickle cell anaemia.

    Science.gov (United States)

    Jaja, S I; Ogungbemi, S O; Kehinde, M O; Anigbogu, C N

    2016-06-01

    The effect of l-arginine on liver function in SCD has received little or no attention. The effect of a chronic, oral, low-dose supplementation with l-arginine (1gm/day for 6 weeks) on some liver enzymes, lipid peroxidation and nitric oxide metabolites was studied in 20 normal (non-sickle cell anaemia; NSCA) subjects and 20 sickle cell anaemia (SCA) subjects. Ten milliliters of blood was withdrawn from an ante-cubital vein for the estimation of plasma arginine concentration ([R]), alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and alkaline phosphatase (ALP), plasma total bilirubin concentration [TB], malondialdehyde concentration [MDA] and nitric oxide metabolites concentration [NOx]. Before supplementation, ALT, AST, ALP (pNOx] were higher in NSCA subjects (pNOX] in SCA than in NSCA subjects (plow-dose supplementation with l-arginine improved liver function, oxidative stress, plasma arginine concentration and nitric oxide metabolites levels in NSCA and SCA subjects. Responses in SCA subjects to l-arginine were more sensitive than in NSCA subjects. PMID:27156372

  11. Induction of ROS generation by fluconazole in Candida glabrata: activation of antioxidant enzymes and oxidative DNA damage.

    Science.gov (United States)

    Mahl, Camila Donato; Behling, Camile Saul; Hackenhaar, Fernanda S; de Carvalho e Silva, Mélany Natuane; Putti, Jordana; Salomon, Tiago B; Alves, Sydney Hartz; Fuentefria, Alexandre; Benfato, Mara S

    2015-07-01

    In this study, we assessed the generation of reactive oxygen species (ROS) induced by subinhibitory concentration of fluconazole in susceptible and resistant Candida glabrata strains at stationary growth phase and measured their oxidative responses parameters: glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione-S-transferase (GST), consumption of hydrogen peroxide, and total glutathione, as well as oxidative damage in lipids, proteins, and DNA. Data showed that fluconazole increased generation of ROS and GPx and SOD enzymatic activity in treated cells; however, these enzymatic activities did not differ between resistant and susceptible strains. Susceptible strains exhibited higher GST activity than resistant, and when susceptible cells were treated with fluconazole, GST activity decreased. Fluconazole treatment cause oxidative damage only in DNA. There are a possible participation of ROS, as organic peroxides and O2(•-), in antifungal mechanism of fluconazole, which results in higher GPx and SOD enzymatic activities and oxidative DNA damage in C. glabrata.

  12. Dietary antioxidant supplementation enhances lipid and protein oxidative stability of chicken broiler meat through promotion of antioxidant enzyme activity.

    Science.gov (United States)

    Delles, Rebecca M; Xiong, Youling L; True, Alma D; Ao, Touying; Dawson, Karl A

    2014-06-01

    Recent nutrigenomic studies have shown that animal nutrition can have a major influence on tissue gene expression. Dietary antioxidant supplements can enhance the quality of meat through modification of tissue metabolic processes. This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler breast meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin packaging systems during retail display at 2 to 4°C for up to 21 d. Broilers were fed either a diet with a low-oxidized (peroxide value 23 mEq of O2/kg) or high-oxidized (peroxide value 121 mEq of O2/kg) oil, supplemented with or without an algae-based Se yeast and organic mineral antioxidant pack for 42 d. Lipid and protein oxidation and tissue enzymatic activity were analyzed. In all packaging systems, lipid oxidation (TBA reactive substances) was inhibited by up to 32.5% (P antioxidant-supplemented diet when compared with diets without antioxidants, particularly in the HiOx and PVC systems. Protein sulfhydryls were significantly protected by antioxidant diets (e.g., by 14.6 and 17.8% for low-and high-oxidized dietary groups, respectively, in PVC d 7 samples). Glutathione peroxidase, catalase, and superoxide dismutase activities were significantly higher (P antioxidant-supplemented diets compared with the basal diet, regardless of oil quality. Also, serum carbonyls were lower in broilers fed a low-oxidized antioxidant-supplemented treatment. The results demonstrate that dietary antioxidants can minimize the oxidative instability of proteins and lipids, and the protection may be linked to improved cellular antioxidant enzymatic activity.

  13. The Anopheles gambiae Oxidation Resistance 1 (OXR1) Gene Regulates Expression of Enzymes That Detoxify Reactive Oxygen Species

    OpenAIRE

    Jaramillo-Gutierrez, Giovanna; Molina-Cruz, Alvaro; Kumar, Sanjeev; Barillas-Mury, Carolina

    2010-01-01

    Background OXR1 is an ancient gene, present in all eukaryotes examined so far that confers protection from oxidative stress by an unknown mechanism. The most highly conserved region of the gene is the carboxyl-terminal TLDc domain, which has been shown to be sufficient to prevent oxidative damage. Methodology/Principal Findings OXR1 has a complex genomic structure in the mosquito A. gambiae, and we confirm that multiple splice forms are expressed in adult females. Our studies revealed that OX...

  14. Dietary antioxidant supplementation enhances lipid and protein oxidative stability of chicken broiler meat through promotion of antioxidant enzyme activity1

    Science.gov (United States)

    Delles, Rebecca M.; Xiong, Youling L.; True, Alma D.; Ao, Touying; Dawson, Karl A.

    2014-01-01

    Recent nutrigenomic studies have shown that animal nutrition can have a major influence on tissue gene expression. Dietary antioxidant supplements can enhance the quality of meat through modification of tissue metabolic processes. This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler breast meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin packaging systems during retail display at 2 to 4°C for up to 21 d. Broilers were fed either a diet with a low-oxidized (peroxide value 23 mEq of O2/kg) or high-oxidized (peroxide value 121 mEq of O2/kg) oil, supplemented with or without an algae-based Se yeast and organic mineral antioxidant pack for 42 d. Lipid and protein oxidation and tissue enzymatic activity were analyzed. In all packaging systems, lipid oxidation (TBA reactive substances) was inhibited by up to 32.5% (P < 0.05) with an antioxidant-supplemented diet when compared with diets without antioxidants, particularly in the HiOx and PVC systems. Protein sulfhydryls were significantly protected by antioxidant diets (e.g., by 14.6 and 17.8% for low-and high-oxidized dietary groups, respectively, in PVC d 7 samples). Glutathione peroxidase, catalase, and superoxide dismutase activities were significantly higher (P < 0.05) in antioxidant-supplemented diets compared with the basal diet, regardless of oil quality. Also, serum carbonyls were lower in broilers fed a low-oxidized antioxidant-supplemented treatment. The results demonstrate that dietary antioxidants can minimize the oxidative instability of proteins and lipids, and the protection may be linked to improved cellular antioxidant enzymatic activity. PMID:24879706

  15. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 226 (FGE.226): Consideration of genotoxicity data on one α,β-unsaturated aldehyde from chemical subgroup 1.1.1(b) of FGE.19 by EFSA

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of one flavouring substance from subgroup 1.1.1(b) of FGE.19 in the Flavouring Group Evaluation 226. The Flavour Industry has provi...

  16. Molecular Structure and Reactivity in the Pyrolysis of Aldehydes

    Science.gov (United States)

    Sias, Eric; Cole, Sarah; Sowards, John; Warner, Brian; Wright, Emily; McCunn, Laura R.

    2016-06-01

    The effect of alkyl chain structure on pyrolysis mechanisms has been investigated in a series of aldehydes. Isovaleraldehyde, CH_3CH(CH_3)CH_2CHO, and pivaldehyde, (CH_3)_3CCHO, were subject to thermal decomposition in a resistively heated SiC tubular reactor at 800-1200 °C. Matrix-isolation FTIR spectroscopy was used to identify pyrolysis products. Carbon monoxide and isobutene were major products from each of the aldehydes, which is consistent with what is known from previous studies of unbranched alkyl-chain aldehydes. Other products observed include vinyl alcohol, propene, acetylene, and ethylene, revealing complexities to be considered in the pyrolysis of large, branched-chain aldehydes.

  17. NITRIC OXIDE (NO, CITRULLINE - NO CYCLE ENZYMES, GLUTAMINE SYNTHETASE AND OXIDATIVE STRESS IN ANOXIA (HYPOBARIC HYPOXIA AND REPERFUSION IN RAT BRAIN

    Directory of Open Access Journals (Sweden)

    M. Swamy, Mohd Jamsani Mat Salleh, K. N .S. Sirajudeen, Wan Roslina Wan Yusof, G. Chandran

    2010-01-01

    Full Text Available Nitric oxide is postulated to be involved in the pathophysiology of neurological disorders due to hypoxia/ anoxia in brain due to increased release of glutamate and activation of N-methyl-D-aspartate receptors. Reactive oxygen species have been implicated in pathophysiology of many neurological disorders and in brain function. To understand their role in anoxia (hypobaric hypoxia and reperfusion (reoxygenation, the nitric oxide synthase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase and arginase activities along with the concentration of nitrate /nitrite, thiobarbituric acid reactive substances and total antioxidant status were estimated in cerebral cortex, cerebellum and brain stem of rats subjected to anoxia and reperfusion. The results of this study clearly demonstrated the increased production of nitric oxide by increased activity of nitric oxide synthase. The increased activities of argininosuccinate synthetase and argininosuccinate lyase suggest the increased and effective recycling of citrulline to arginine in anoxia, making nitric oxide production more effective and contributing to its toxic effects. The decreased activity of glutamine synthetase may favor the prolonged availability of glutamic acid causing excitotoxicity leading to neuronal damage in anoxia. The increased formation of thiobarbituric acid reactive substances and decreased total antioxidant status indicate the presence of oxidative stress in anoxia and reperfusion. The increased arginase and sustained decrease of GS activity in reperfusion group likely to be protective.

  18. Effects of Different Levels of Water Stress on Leaf Water Potential, Stomatal Resistance, Protein and Chlorophyll Content and Certain Anti-oxidative Enzymes in Tomato Plants

    Institute of Scientific and Technical Information of China (English)

    Hatem Zgallai; Kathy Steppe; Raoul Lemeur

    2006-01-01

    A greenhouse experiment was performed in order to investigate the effects of different levels of water stress on leaf water potential (ψw), stomatal resistance (rs), protein content and chlorophyll (Chi) content of tomato plants (Lycopersicon esculentum Mill. cv. Nikita). Water stress was induced by adding polyethylene glycol (PEG 6 000) to the nutrient solution to reduce the osmotic potential (ψs). We investigated the behavior of anti-oxidant enzymes, such as catalase (CAT) and superoxide dismutase (SOD), during the development of water stress. Moderate and severe water stress (i.e.ψs= -0.51 and -1.22 MPa, respectively) caused a decrease in ψw for all treated (water-stressed) plants compared with control plants, with the reduction being more pronounced for severely stressed plants. In addition, rs was significantly affected by the induced water stress and a decrease in leaf soluble proteins and Chi content was observed. Whereas CAT activity remained constant, SOD activity was increased in water-stressed plants compared with unstressed plants. These results indicate the possible role of SOD as an anti-oxidant protector system for plants under water stress conditions. Moreover, it suggests the possibility of using this enzyme as an additional screening criterion for detecting water stress in plants.

  19. Tamarind seed coat extract restores reactive oxygen species through attenuation of glutathione level and antioxidant enzyme expression in human skin fibroblasts in response to oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Oranuch Nakchat; Nonthaneth Nalinratana; Duangdeun Meksuriyen; Sunanta Pongsamart

    2014-01-01

    Objective:To investigate the role and mechanism of tamarind seed coat extract (TSCE) on normal human skin fibroblast CCD-1064Sk cells under normal and oxidative stress conditions induced by hydrogen peroxide (H2O2). Methods:Tamarind seed coats were extracted with boiling water and then partitioned with ethyl acetate before the cell analysis. Effect of TSCE on intracellular reactive oxygen species (ROS), glutathione (GSH) level, antioxidant enzymes such as superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase activity including antioxidant protein expression was investigated. Results: TSCE significantly attenuated intracellular ROS in the absence and presence of H2O2 by increasing GSH level. In the absence of H2O2, TSCE significantly enhanced SOD and catalase activity but did not affected on GPx. Meanwhile, TSCE significantly increased the protein expression of SOD and GPx in H2O2-treated cells. Conclusions: TSCE exhibited antioxidant activities by scavenging ROS, attenuating GSH level that could protect human skin fibroblast cells from oxidative stress. Our results highlight the antioxidant mechanism of tamarind seed coat through an antioxidant enzyme system, the extract potentially benefits for health food and cosmeceutical application of tamarind seed coat.

  20. Recyclable enzyme mimic of cubic Fe3O4 nanoparticles loaded on graphene oxide-dispersed carbon nanotubes with enhanced peroxidase-like catalysis and electrocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hua; Li, Shuai; Si, Yanmei; Sun, Zhongzhao; Li, Shuying; Lin, Yuehe

    2014-01-01

    Fe3O4 nanoparticles as nanocatalysts may present peroxidase-like catalysis activities and high electrocatalysis if loaded on conductive carbon nanotube (CNT) supports; however, their catalysis performances in an aqueous system might still be challenged by the poor aqueous dispersion of hydrophobic carbon supports and/or low stability of loaded iron catalysts. In this work, amphiphilic graphene oxide nanosheets were employed as “surfactant” to disperse CNTs to create stable graphene oxide-dispersed CNT (GCNT) supports in water for covalently loading cubic Fe3O4 nanoparticles with improved distribution and binding efficiency. Compared with original Fe3O4 nanos and CNT-loaded Fe3O4 nanocomplex, the prepared GCNT–Fe3O4 nanocomposite could achieve higher aqueous stability and, especially, much stronger peroxidase-like catalysis and electrocatalysis to H2O2, presumably resulting from the synergetic effects of two conductive carbon supports and cubic Fe3O4 nanocatalysts effectively loaded. Colorimetric and direct electrochemical detections of H2O2 and glucose using the GCNT–Fe3O4 nanocomposite were conducted with high detection sensitivities, demonstrating the feasibility of practical sensing applications. Such a magnetically recyclable “enzyme mimic” may circumvent some disadvantages of natural protein enzymes and common inorganic catalysts, featuring the multi-functions of high peroxidase-like catalysis, strong electrocatalysis, magnetic separation/recyclability, environmental stability, and direct H2O2 electrochemistry.

  1. Metabolism of monoterpenes: oxidation of isopiperitenol to isopiperitenone, and subsequent isomerization to piperitenone by soluble enzyme preparations from peppermint (Mentha piperita) leaves

    Energy Technology Data Exchange (ETDEWEB)

    Kjonaas, R.B.; Venkatachalam, K.V.; Croteau, R.

    1985-04-01

    Soluble enzyme extracts from peppermint leaves, when treated with polystyrene resin to remove endogenous monoterpenes and assayed with unlabeled substrates coupled with capillary gas-liquid chromatographic/mass spectrometric detection methods, were shown to oxidize isopiperitenol to isopiperitenone, and to isomerize isopiperitenone to piperitenone. The enzymes responsible for the monoterpenol dehydrogenation and the subsequent allylic isomerization were separated and partially purified by chromatography on Sephadex G-150, and were shown to have molecular weights of approximately 66,000 and 54,000, respectively. The general properties of the NAD-dependent dehydrogenase were examined, and specificity studies indicated that a double bond adjacent to the carbinol carbon was a required structural feature of the monoterpenol substrate. General properties of the isomerase were also determined, and it was demonstrated that the double bond migration catalyzed by this enzyme involved an intramolecular 1,3-hydrogen transfer. These enzymatic transformations represent two key steps in the metabolic pathway for the conversion of the initially formed cyclic olefin, (+/-)-limonene, to (-)-menthol and related monoterpenes characteristic of peppermint. Some stereochemical features of these reactions, and of the overall biogenetic scheme, are described. 39 references, 5 figures.

  2. Two-Step biocatalytic conversion of an ester to an aldehyde in reverse micelles.

    Science.gov (United States)

    Yang, F; Russell, A J

    1994-02-01

    Lipases from Candida cyclindracea (L-1754) and wheat germ (L-3001) have been used to hydrolyze esters to their corresponding alcohols and acids in reverse micelles. Alcohol dehydrogenase from baker's yeast (YADH) was subsequently used to reduce the alcohol products to aldehydes. Cofactor recycling in the redox reaction was achieved using a sacrificial cosubstrate, as described previously. Four surfactants (sodium dioctylsulfosuccinate, Nonidet P-40 with Triton X-35, polyoxyethylene, 10-cetyl-ether, polyoxyethylene sorbitan trioleate) were employed to determine the effect of amphiphile on ester hydrolysis and redox reaction rates separately. The effect of type of organic solvent, W(0) [(water]/[surfactant)], and substrate concentration on separte enzyme activity were also investigated. A brief investigation of a single phase, two-step reaction catalyzed by the combination of lipase and YADH in reverse micelles is also reported. The activities of the enzymes are significantly different when used together instead of independently. (c) 1994 John Wiley & Sons, Inc.

  3. Amine-functionalized porous silicas as adsorbents for aldehyde abatement.

    Science.gov (United States)

    Nomura, Akihiro; Jones, Christopher W

    2013-06-26

    A series of aminopropyl-functionalized silicas containing of primary, secondary, or tertiary amines is fabricated via silane-grafting on mesoporous SBA-15 silica and the utility of each material in the adsorption of volatile aldehydes from air is systematically assessed. A particular emphasis is placed on low-molecular-weight aldehydes such as formaldehyde and acetaldehyde, which are highly problematic volatile organic compound (VOC) pollutants. The adsorption tests demonstrate that the aminosilica materials with primary amines most effectively adsorbed formaldehyde with an adsorption capacity of 1.4 mmolHCHO g(-1), whereas the aminosilica containing secondary amines showed lower adsorption capacity (0.80 mmolHCHO g(-1)) and the aminosilica containing tertiary amines adsorbed a negligible amount of formaldehyde. The primary amine containing silica also successfully abated higher aldehyde VOC pollutants, including acetaldehyde, hexanal, and benzaldehyde, by effectively adsorbing them. The adsorption mechanism is investigated by (13)C CP MAS solid-state NMR and FT-Raman spectroscopy, and it is demonstrated that the aldehydes are chemically attached to the surface of aminosilica in the form of imines and hemiaminals. The high aldehyde adsorption capacities of the primary aminosilicas in this study demonstrate the utility of amine-functionalized silica materials for reduction of gaseous aldehydes.

  4. The Multifunctional β-Oxidation Enzyme Is Required for Full Symptom Development by the Biotrophic Maize Pathogen Ustilago maydis▿

    OpenAIRE

    Klose, Jana; Kronstad, James W.

    2006-01-01

    The transition from yeast-like to filamentous growth in the biotrophic fungal phytopathogen Ustilago maydis is a crucial event for pathogenesis. Previously, we showed that fatty acids induce filamentation in U. maydis and that the resulting hyphal cells resemble the infectious filaments observed in planta. To explore the potential metabolic role of lipids in the morphological transition and in pathogenic development in host tissue, we deleted the mfe2 gene encoding the multifunctional enzyme ...

  5. YNL134C from Saccharomyces cerevisiae encodes a novel protein with aldehyde reductase activity for detoxification of furfural derived from lignocellulosic biomass.

    Science.gov (United States)

    Zhao, Xianxian; Tang, Juan; Wang, Xu; Yang, Ruoheng; Zhang, Xiaoping; Gu, Yunfu; Li, Xi; Ma, Menggen

    2015-05-01

    Furfural and 5-hydroxymethylfurfural (HMF) are the two main aldehyde compounds derived from pentoses and hexoses, respectively, during lignocellulosic biomass pretreatment. These two compounds inhibit microbial growth and interfere with subsequent alcohol fermentation. Saccharomyces cerevisiae has the in situ ability to detoxify furfural and HMF to the less toxic 2-furanmethanol (FM) and furan-2,5-dimethanol (FDM), respectively. Herein, we report that an uncharacterized gene, YNL134C, was highly up-regulated under furfural or HMF stress and Yap1p and Msn2/4p transcription factors likely controlled its up-regulated expression. Enzyme activity assays showed that YNL134C is an NADH-dependent aldehyde reductase, which plays a role in detoxification of furfural to FM. However, no NADH- or NADPH-dependent enzyme activity was observed for detoxification of HMF to FDM. This enzyme did not catalyse the reverse reaction of FM to furfural or FDM to HMF. Further studies showed that YNL134C is a broad-substrate aldehyde reductase, which can reduce multiple aldehydes to their corresponding alcohols. Although YNL134C is grouped into the quinone oxidoreductase family, no quinone reductase activity was observed using 1,2-naphthoquinone or 9,10-phenanthrenequinone as a substrate, and phylogenetic analysis indicates that it is genetically distant to quinone reductases. Proteins similar to YNL134C in sequence from S. cerevisiae and other microorganisms were phylogenetically analysed.

  6. Enantiospecific Total Synthesis of the Important Biogenetic Intermediates Along the Ajmaline Pathway, (+)-Polyneuridine and (+)-Polyneuridine Aldehyde, as well as 16-Epi-Vellosimine and Macusine A

    Science.gov (United States)

    Yin, Wenyuan; Kabir, M. Shahjahan; Wang, Zhijian; Rallapalli, Sundari K.; Ma, Jun; Cook, James M.

    2011-01-01

    The first stereospecific synthesis of polyneuridine aldehyde (6), 16-epi-vellosimine (7), (+)-polyneuridine (8), and (+)-macusine A (9) has been accomplished from commercially available D-(+)-tryptophan methyl ester. D-(+)-Tryptophan has served here both as the chiral auxiliary and the starting material for the synthesis of the common intermediate, (+)-vellosimine (13). This alkaloid was available in enantiospecific fashion in seven reaction vessels in 27% overall yield from D-(+)-trytophan methyl ester (14) via a combination of the asymmetric Pictet-Spengler reaction, Dieckmann cyclization, and a stereocontrolled intramolecular enolate-driven palladium-mediated cross-coupling reaction. A new process for this stereocontrolled intramolecular cross-coupling has been developed via a copper-mediated process. The initial results of this investigation indicated that an enolate driven palladium-mediated cross-coupling reaction can be accomplished by a copper-mediated process which is less expensive and much easier to work-up. An enantiospecific total synthesis of (+)-polyneuridine aldehyde (6), which has been proposed as an important biogenetic intermediate in the biosynthesis of quebrachidine (2), was then accomplished in an overall yield of 14.1% in 13 reaction vessels from D-(+)-tryptophan methyl ester (14). Aldehyde 13 was protected as the Na-Boc aldehyde 32 and then converted into the prochiral C (16)-quaternary diol 12 via the practical Tollens’ reaction and deprotection. The DDQ-mediated oxidative cyclization and TFA/Et3SiH reductive cleavage served as protection/deprotection steps to provide a versatile entry into the three alkaloids, polyneuridine aldehyde (6), polyneuridine (8) and macusine A (9) from the quarternary diol 12. The oxidation of the 16-hydroxymethyl group present in the axial position was achieved with the Corey-Kim reagent to provide the desired β-axial aldehydes, polyneuridine aldehyde (6) and 16-epi-vellosimine (7) with 100

  7. Enantiospecific total synthesis of the important biogenetic intermediates along the ajmaline pathway, (+)-polyneuridine and (+)-polyneuridine aldehyde, as well as 16-epivellosimine and macusine A.

    Science.gov (United States)

    Yin, Wenyuan; Kabir, M Shahjahan; Wang, Zhijian; Rallapalli, Sundari K; Ma, Jun; Cook, James M

    2010-05-21

    The first stereospecific synthesis of polyneuridine aldehyde (6), 16-epivellosimine (7), (+)-polyneuridine (8), and (+)-macusine A (9) has been accomplished from commercially available d-(+)-tryptophan methyl ester. d-(+)-Tryptophan has served here both as the chiral auxiliary and the starting material for the synthesis of the common intermediate, (+)-vellosimine (13). This alkaloid was available in enantiospecific fashion in seven reaction vessels in 27% overall yield from d-(+)-trytophan methyl ester (14) via a combination of the asymmetric Pictet-Spengler reaction, Dieckmann cyclization, and a stereocontrolled intramolecular enolate-driven palladium-mediated cross-coupling reaction. A new process for this stereocontrolled intramolecular cross-coupling has been developed via a copper-mediated process. The initial results of this investigation indicated that an enolate-driven palladium-mediated cross-coupling reaction can be accomplished by a copper-mediated process which is less expensive and much easier to work up. An enantiospecific total synthesis of (+)-polyneuridine aldehyde (6), which has been proposed as an important biogenetic intermediate in the biosynthesis of quebrachidine (2), was then accomplished in an overall yield of 14.1% in 13 reaction vessels from d-(+)-tryptophan methyl ester (14). Aldehyde 13 was protected as the N(a)-Boc aldehyde 32 and then converted into the prochiral C(16)-quaternary diol 12 via the practical Tollens' reaction and deprotection. The DDQ-mediated oxidative cyclization and TFA/Et(3)SiH reductive cleavage served as protection/deprotection steps to provide a versatile entry into the three alkaloids polyneuridine aldehyde (6), polyneuridine (8), and macusine A (9) from the quarternary diol 12. The oxidation of the 16-hydroxymethyl group present in the axial position was achieved with the Corey-Kim reagent to provide the desired beta-axial aldehydes, polyneuridine aldehyde (6), and 16-epivellosimine (7) with 100

  8. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 10, Revision 3 (FGE.10Rev3): Aliphatic primary and secondary saturated and unsaturated alcohols, aldehydes, acetals, carboxylic acids and esters containing an additional oxygenated functional group and lactones from chemical groups 9, 13 and 30

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 63 flavouring substances in the Flavouring Group Evaluation 10, including additional two substances in this Revision 3, using the Procedure in Commission R...... for the materials of commerce have also been considered. For four substances evaluated through the Procedure, the stereoisomeric composition has not been specified sufficiently....

  9. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 12, Revision 4 (FGE.12Rev4): primary saturated or unsaturated alicyclic alcohols, aldehydes, acids and esters from chemical groups 1 and 7

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate 12 flavouring substances in Flavouring Group Evaluation 12, Revision 4 (FGE.12Rev4), including two additional substances, using the Procedure in Commission...... of commerce have also been considered. Specifications including complete purity criteria and identity for the materials of commerce have been provided for all 12 candidate substances....

  10. Oxidative and nitrative stress and pro-inflammatory cytokines in Mucopolysaccharidosis type II patients: effect of long-term enzyme replacement therapy and relation with glycosaminoglycan accumulation.

    Science.gov (United States)

    Jacques, Carlos Eduardo Diaz; Donida, Bruna; Mescka, Caroline P; Rodrigues, Daiane G B; Marchetti, Desirèe P; Bitencourt, Fernanda H; Burin, Maira G; de Souza, Carolina F M; Giugliani, Roberto; Vargas, Carmen Regla

    2016-09-01

    Mucopolysaccharidosis type II (MPS II) is a lysosomal storage disease caused by a deficient activity of iduronate-2-sulfatase, leading to abnormal accumulation of glycosaminoglycans (GAG). The main treatment for MPS II is enzyme replacement therapy (ERT). Previous studies described potential benefits of six months of ERT against oxidative stress in patients. Thus, the aim of this study was to investigate oxidative, nitrative and inflammatory biomarkers in MPS II patients submitted to long term ERT. It were analyzed urine and blood samples from patients on ERT (mean time: 5.2years) and healthy controls. Patients presented increased levels of lipid peroxidation, assessed by urinary 15-F2t-isoprostane and plasmatic thiobarbituric acid-reactive substances. Concerning to protein damage, urinary di-tyrosine (di-Tyr) was increased in patients; however, sulfhydryl and carbonyl groups in plasma were not altered. It were also verified increased levels of urinary nitrate+nitrite and plasmatic nitric oxide (NO) in MPS II patients. Pro-inflammatory cytokines IL-1β and TNF-α were increased in treated patients. GAG levels were correlated to di-Tyr and nitrate+nitrite. Furthermore, IL-1β was positively correlated with TNF-α and NO. Contrastingly, we did not observed alterations in erythrocyte superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities, in reduced glutathione content and in the plasmatic antioxidant capacity. Although some parameters were still altered in MPS II patients, these results may suggest a protective role of long-term ERT against oxidative stress, especially upon oxidative damage to protein and enzymatic and non-enzymatic defenses. Moreover, the redox imbalance observed in treated patients seems to be GAG- and pro-inflammatory cytokine-related. PMID:27251652

  11. Inhibition of human alcohol and aldehyde dehydrogenases by aspirin and salicylate: assessment of the effects on first-pass metabolism of ethanol.

    Science.gov (United States)

    Lee, Shou-Lun; Lee, Yung-Pin; Wu, Min-Li; Chi, Yu-Chou; Liu, Chiu-Ming; Lai, Ching-Long; Yin, Shih-Jiun

    2015-05-01

    Previous studies have reported that aspirin significantly reduced the first-pass metabolism (FPM) of ethanol in humans thereby increasing adverse effects of alcohol. The underlying causes, however, remain poorly understood. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), principal enzymes responsible for metabolism of ethanol, are complex enzyme families that exhibit functional polymorphisms among ethnic groups and distinct tissue distributions. We investigated the inhibition profiles by aspirin and its major metabolite salicylate of ethanol oxidation by recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and acetaldehyde oxidation by ALDH1A1 and ALDH2, at pH 7.5 and 0.5 mM NAD(+). Competitive inhibition pattern was found to be a predominant type among the ADHs and ALDHs studied, although noncompetitive and uncompetitive inhibitions were also detected in a few cases. The inhibition constants of salicylate for the ADHs and ALDHs were considerably lower than that of aspirin with the exception of ADH1A that can be ascribed to a substitution of Ala-93 at the bottom of substrate pocket as revealed by molecular docking experiments. Kinetic inhibition equation-based simulations show at higher therapeutic levels of blood plasma salicylate (1.5 mM) that the decrease of activities at 2-10 mM ethanol for ADH1A/ADH2 and ADH1B2/ADH1B3 are predicted to be 75-86% and 31-52%, respectively, and that the activity decline for ALDH1A1 and ALDH2 at 10-50 μM acetaldehyde to be 62-73%. Our findings suggest that salicylate may substantially inhibit hepatic FPM of alcohol at both the ADH and ALDH steps when concurrent intaking aspirin.

  12. Inhibition of human alcohol and aldehyde dehydrogenases by aspirin and salicylate: assessment of the effects on first-pass metabolism of ethanol.

    Science.gov (United States)

    Lee, Shou-Lun; Lee, Yung-Pin; Wu, Min-Li; Chi, Yu-Chou; Liu, Chiu-Ming; Lai, Ching-Long; Yin, Shih-Jiun

    2015-05-01

    Previous studies have reported that aspirin significantly reduced the first-pass metabolism (FPM) of ethanol in humans thereby increasing adverse effects of alcohol. The underlying causes, however, remain poorly understood. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), principal enzymes responsible for metabolism of ethanol, are complex enzyme families that exhibit functional polymorphisms among ethnic groups and distinct tissue distributions. We investigated the inhibition profiles by aspirin and its major metabolite salicylate of ethanol oxidation by recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and acetaldehyde oxidation by ALDH1A1 and ALDH2, at pH 7.5 and 0.5 mM NAD(+). Competitive inhibition pattern was found to be a predominant type among the ADHs and ALDHs studied, although noncompetitive and uncompetitive inhibitions were also detected in a few cases. The inhibition constants of salicylate for the ADHs and ALDHs were considerably lower than that of aspirin with the exception of ADH1A that can be ascribed to a substitution of Ala-93 at the bottom of substrate pocket as revealed by molecular docking experiments. Kinetic inhibition equation-based simulations show at higher therapeutic levels of blood plasma salicylate (1.5 mM) that the decrease of activities at 2-10 mM ethanol for ADH1A/ADH2 and ADH1B2/ADH1B3 are predicted to be 75-86% and 31-52%, respectively, and that the activity decline for ALDH1A1 and ALDH2 at 10-50 μM acetaldehyde to be 62-73%. Our findings suggest that salicylate may substantially inhibit hepatic FPM of alcohol at both the ADH and ALDH steps when concurrent intaking aspirin. PMID:25772736

  13. Spectroscopic Analyses of the Biofuels-Critical Phytochemical Coniferyl Alcohol and Its Enzyme-Catalyzed Oxidation Products

    Energy Technology Data Exchange (ETDEWEB)

    Achyuthan, Komandoor; Adams, Paul; Simmons, Blake; Singh, Anup

    2011-07-13

    Lignin composition (monolignol types of coniferyl, sinapyl or p-coumaryl alcohol) is causally related to biomass recalcitrance. We describe multiwavelength (220, 228, 240, 250, 260, 290, 295, 300, 310 or 320 nm) absorption spectroscopy of coniferyl alcohol and its laccase- or peroxidase-catalyzed products during real time kinetic, pseudo-kinetic and endpoint analyses, in optical turn on or turn off modes, under acidic or basic conditions. Reactions in microwell plates and 100 mu L volumes demonstrated assay miniaturization and high throughput screening capabilities. Bathochromic and hypsochromic shifts along with hyperchromicity or hypochromicity accompanied enzymatic oxidations by laccase or peroxidase. The limits of detection and quantitation of coniferyl alcohol averaged 2.4 and 7.1 mu M respectively, with linear trend lines over 3 to 4 orders of magnitude. Coniferyl alcohol oxidation was evident within 10 minutes or with 0.01 mu g/mL laccase and 2 minutes or 0.001 mu g/mL peroxidase. Detection limit improved to 1.0 mu M coniferyl alcohol with Km of 978.7 +/- 150.7 mu M when examined at 260 nm following 30 minutes oxidation with 1.0 mu g/mL laccase. Our assays utilized the intrinsic spectroscopic properties of coniferyl alcohol or its oxidation products for enabling detection, without requiring chemical synthesis or modification of the substrate or product(s). These studies facilitate lignin compositional analyses and augment pretreatment strategies for reducing biomass recalcitrance.

  14. Inhibition of human alcohol and aldehyde dehydrogenases by acetaminophen: Assessment of the effects on first-pass metabolism of ethanol.

    Science.gov (United States)

    Lee, Yung-Pin; Liao, Jian-Tong; Cheng, Ya-Wen; Wu, Ting-Lun; Lee, Shou-Lun; Liu, Jong-Kang; Yin, Shih-Jiun

    2013-11-01

    Acetaminophen is one of the most widely used over-the-counter analgesic, antipyretic medications. Use of acetaminophen and alcohol are commonly associated. Previous studies showed that acetaminophen might affect bioavailability of ethanol by inhibiting gastric alcohol dehydrogenase (ADH). However, potential inhibitions by acetaminophen of first-pass metabolism (FPM) of ethanol, catalyzed by the human ADH family and by relevant aldehyde dehydrogenase (ALDH) isozymes, remain undefined. ADH and ALDH both exhibit racially distinct allozymes and tissue-specific distribution of isozymes, and are principal enzymes responsible for ethanol metabolism in humans. In this study, we investigated acetaminophen inhibition of ethanol oxidation with recombinant human ADH1A, ADH1B1, ADH1B2, ADH1B3, ADH1C1, ADH1C2, ADH2, and ADH4, and inhibition of acetaldehyde oxidation with recombinant human ALDH1A1 and ALDH2. The investigations were done at near physiological pH 7.5 and with a cytoplasmic coenzyme concentration of 0.5 mM NAD(+). Acetaminophen acted as a noncompetitive inhibitor for ADH enzymes, with the slope inhibition constants (Kis) ranging from 0.90 mM (ADH2) to 20 mM (ADH1A), and the intercept inhibition constants (Kii) ranging from 1.4 mM (ADH1C allozymes) to 19 mM (ADH1A). Acetaminophen exhibited noncompetitive inhibition for ALDH2 (Kis = 3.0 mM and Kii = 2.2 mM), but competitive inhibition for ALDH1A1 (Kis = 0.96 mM). The metabolic interactions between acetaminophen and ethanol/acetaldehyde were assessed by computer simulation using inhibition equations and the determined kinetic constants. At therapeutic to subtoxic plasma levels of acetaminophen (i.e., 0.2-0.5 mM) and physiologically relevant concentrations of ethanol (10 mM) and acetaldehyde (10 μm) in target tissues, acetaminophen could inhibit ADH1C allozymes (12-26%) and ADH2 (14-28%) in the liver and small intestine, ADH4 (15-31%) in the stomach, and ALDH1A1 (16-33%) and ALDH2 (8.3-19%) in all 3 tissues. The

  15. Hepatic ischemia-reperfusion syndrome after partial liver resection (LR): hepatic venous oxygen saturation, enzyme pattern, reduced and oxidized glutathione, procalcitonin and interleukin-6.

    Science.gov (United States)

    Kretzschmar, Michael; Krüger, Antie; Schirrmeister, Wulf

    2003-06-01

    The hepatic ischemia-reperfusion syndrome was investigated in 28 patients undergoing elective partial liver resection with intraoperative occlusion of hepatic inflow (Pringle maneuver) using the technique of liver vein catheterization. Hepatic venous oxygen saturation (ShvO2) was monitored continuously up to 24 hours after surgery. Aspartate aminotransferase, glutamate dehydrogenase, gamma-glutamyl transpeptidase, pseudocholinesterase, alpha-glutathione S-transferase, reduced and oxidized glutathione, procalcitonine, and interleukin-6 were serially measured both before and after Pringle maneuver during the resection and postoperatively in arterial and/or hepatic venous blood. ShvO2 measurement demonstrated that peri- and postoperative management was suitable to maintain an optimal hepatic oxygen supply. As expected, we were able to demonstrate a typical enzyme pattern of postischemic liver injury. There was a distinct decrease of reduced glutathione levels both in arterial and hepatic venous plasma after LR accompanied by a strong increase in oxidized glutathione concentration during the phase of reperfusion. We observed increases in procalcitonin and interleukin-6 levels both in arterial and hepatic venous blood after declamping. Our data support the view that liver resection in man under conditions of inflow occlusion resulted in ischemic lesion of the liver (loss of glutathione synthesizing capacity with disturbance of protection against oxidative stress) and an additional impairment during reperfusion (liberation of reactive oxygen species, local and systemic inflammation reaction with cytokine production). Additionally, we found some evidence for the assumption that the liver has an export function for reduced glutathione into plasma in man. PMID:12877355

  16. Virgin Olive Oil Enriched with Its Own Phenols or Complemented with Thyme Phenols Improves DNA Protection against Oxidation and Antioxidant Enzyme Activity in Hyperlipidemic Subjects.

    Science.gov (United States)

    Romeu, Marta; Rubió, Laura; Sánchez-Martos, Vanessa; Castañer, Olga; de la Torre, Rafael; Valls, Rosa M; Ras, Rosa; Pedret, Anna; Catalán, Úrsula; López de las Hazas, María del Carmen; Motilva, María J; Fitó, Montserrat; Solà, Rosa; Giralt, Montserrat

    2016-03-01

    The effects of virgin olive oil (VOO) enriched with its own phenolic compounds (PC) and/or thyme PC on the protection against oxidative DNA damage and antioxidant endogenous enzymatic system (AEES) were estimated in 33 hyperlipidemic subjects after the consumption of VOO, VOO enriched with its own PC (FVOO), or VOO complemented with thyme PC (FVOOT). Compared to pre-intervention, 8-hydroxy-2'-deoxyguanosine (a marker for DNA damage) decreased in the FVOO intervention and to a greater extent in the FVOOT with a parallel significant increase in olive and thyme phenolic metabolites. Superoxide dismutase (AEES enzyme) significantly increased in the FVOO intervention and to a greater extent in the FVOOT with a parallel significant increase in thyme phenolic metabolites. When all three oils were compared, FVOOT appeared to have the greatest effect in protecting against oxidative DNA damage and improving AEES. The sustained intake of a FVOOT improves DNA protection against oxidation and AEES probably due to a greater bioavailability of thyme PC in hyperlipidemic subjects. PMID:26889783

  17. Paraoxonases-2 and -3 Are Important Defense Enzymes against Pseudomonas aeruginosa Virulence Factors due to Their Anti-Oxidative and Anti-Inflammatory Properties

    Directory of Open Access Journals (Sweden)

    Eva-Maria Schweikert

    2012-01-01

    Full Text Available The pathogen Pseudomonas aeruginosa causes serious damage in immunocompromised patients by secretion of various virulence factors, among them the quorum sensing N-(3-oxododecanoyl-L-homoserine lactone (3OC12 and the redox-active pyocyanin (PCN. Paraoxonase-2 (PON2 may protect against P. aeruginosa infections, as it efficiently inactivates 3OC12 and diminishes PCN-induced oxidative stress. This defense could be circumvented because 3OC12 mediates intracellular Ca2+-rise in host cells, which causes rapid inactivation and degradation of PON2. Importantly, we recently found that the PON2 paralogue PON3 prevents mitochondrial radical formation. Here we investigated its role as additional potential defense mechanism against P. aeruginosa infections. Our studies demonstrate that PON3 diminished PCN-induced oxidative stress. Moreover, it showed clear anti-inflammatory potential by protecting against NF-κB activation and IL-8 release. The latter similarly applied to PON2. Furthermore, we observed a Ca2+-mediated inactivation and degradation of PON3, again in accordance with previous findings for PON2. Our results suggest that the anti-oxidative and anti-inflammatory functions of PON2 and PON3 are an important part of our innate defense system against P. aeruginosa infections. Furthermore, we conclude that P. aeruginosa circumvents PON3 protection by the same pathway as for PON2. This may help identifying underlying mechanisms in order to sustain the protection afforded by these enzymes.

  18. Purification, crystallization and preliminary X-ray analysis of recombinant betaine aldehyde dehydrogenase 2 (OsBADH2), a protein involved in jasmine aroma, from Thai fragrant rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Crystals of betaine aldehyde dehydrogenase 2 from rice (O. sativa L.) belonged to a C-centred orthorhombic space group and diffraceted X-rays to 2.6 Å resolution. Fragrant rice (Oryza sativa L.) betaine aldehyde dehydrogenase 2 (OsBADH2) is a key enzyme in the synthesis of fragrance aroma compounds. The extremely low activity of OsBADH2 in catalyzing the oxidation of acetaldehyde is believed to be crucial for the accumulation of the volatile compound 2-acetyl-1-pyrroline (2AP) in many scented plants, including fragrant rice. Recombinant fragrant rice OsBADH2 was expressed in Escherichia coli as an N-terminal hexahistidine fusion protein, purified using Ni Sepharose affinity chromatography and crystallized using the microbatch method. Initial crystals were obtained within 24 h using 0.1 M Tris pH 8.5 with 30%(w/v) PEG 4000 and 0.2 M magnesium chloride as the precipitating agent at 291 K. Crystal quality was improved when the enzyme was cocrystallized with NAD+. Improved crystals were grown in 0.1 M HEPES pH 7.4, 24%(w/v) PEG 4000 and 0.2 M ammonium chloride and diffracted to beyond 2.95 Å resolution after being cooled in a stream of N2 immediately prior to X-ray diffraction experiments. The crystals belonged to space group C2221, with unit-cell parameters a = 66.03, b = 183.94, c = 172.28 Å. An initial molecular-replacement solution has been obtained and refinement is in progress

  19. Identification and Overexpression of a Bifunctional Aldehyde/Alcohol Dehydrogenase Responsible for Ethanol Production in Thermoanaerobacter mathranii

    DEFF Research Database (Denmark)

    Yao, Shuo; Just Mikkelsen, Marie

    2010-01-01

    Thermoanaerobacter mathranii contains four genes, adhA, adhB, bdhA and adhE, predicted to code for alcohol dehydrogenases involved in ethanol metabolism. These alcohol dehydrogenases were characterized as NADP(H)-dependent primary alcohol dehydrogenase (AdhA), secondary alcohol dehydrogenase (Adh......B), butanol dehydrogenase (BdhA) and NAD(H)-dependent bifunctional aldehyde/alcohol dehydrogenase (AdhE), respectively. Here we observed that AdhE is an important enzyme responsible for ethanol production in T. mathranii based on the constructed adh knockout strains. An adhE knockout strain fails to produce...... ethanol as a fermentation product, while other adh knockout strains showed no significant difference from the wild type. Further analysis revealed that the ΔadhE strain was defective in aldehyde dehydrogenase activity, but still maintained alcohol dehydrogenase activity. This showed that AdhE is the major...

  20. Improved tolerance to various abiotic stresses in transgenic sweet potato (Ipomoea batatas expressing spinach betaine aldehyde dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Weijuan Fan

    Full Text Available Abiotic stresses are critical delimiters for the increased productivity and cultivation expansion of sweet potato (Ipomoea batatas, a root crop with worldwide importance. The increased production of glycine betaine (GB improves plant tolerance to various abiotic stresses without strong phenotypic changes, providing a feasible approach to improve stable yield production under unfavorable conditions. The gene encoding betaine aldehyde dehydrogenase (BADH is involved in the biosynthesis of GB in plants, and the accumulation of GB by the heterologous overexpression of BADH improves abiotic stress tolerance in plants. This study is to improve sweet potato, a GB accumulator, resistant to multiple abiotic stresses by promoted GB biosynthesis. A chloroplastic BADH gene from Spinacia oleracea (SoBADH was introduced into the sweet potato cultivar Sushu-2 via Agrobacterium-mediated transformation. The overexpression of SoBADH in the transgenic sweet potato improved tolerance to various abiotic stresses, including salt, oxidative stress, and low temperature. The increased BADH activity and GB accumulation in the transgenic plant lines under normal and multiple environmental stresses resulted in increased protection against cell damage through the maintenance of cell membrane integrity, stronger photosynthetic activity, reduced reactive oxygen species (ROS production, and induction or activation of ROS scavenging by the increased activity of free radical-scavenging enzymes. The increased proline accumulation and systemic upregulation of many ROS-scavenging genes in stress-treated transgenic plants also indicated that GB accumulation might stimulate the ROS-scavenging system and proline biosynthesis via an integrative mechanism. This study demonstrates that the enhancement of GB biosynthesis in sweet potato is an effective and feasible approach to improve its tolerance to multiple abiotic stresses without causing phenotypic defects. This strategy for trait

  1. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  2. Magnetically responsive enzyme powders

    International Nuclear Information System (INIS)

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction

  3. Species Differences in the Oxidative Desulfurization of a Thiouracil-Based Irreversible Myeloperoxidase Inactivator by Flavin-Containing Monooxygenase Enzymes.

    Science.gov (United States)

    Eng, Heather; Sharma, Raman; Wolford, Angela; Di, Li; Ruggeri, Roger B; Buckbinder, Leonard; Conn, Edward L; Dalvie, Deepak K; Kalgutkar, Amit S

    2016-08-01

    N1-Substituted-6-arylthiouracils, represented by compound 1 [6-(2,4-dimethoxyphenyl)-1-(2-hydroxyethyl)-2-thioxo-2,3-dihydropyrimidin-4(1H)-one], are a novel class of selective irreversible inhibitors of human myeloperoxidase. The present account is a summary of our in vitro studies on the facile oxidative desulfurization in compound 1 to a cyclic ether metabolite M1 [5-(2,4-dimethoxyphenyl)-2,3-dihydro-7H-oxazolo[3,2-a]pyrimidin-7-one] in NADPH-supplemented rats (t1/2 [half-life = mean ± S.D.] = 8.6 ± 0.4 minutes) and dog liver microsomes (t1/2 = 11.2 ± 0.4 minutes), but not in human liver microsomes (t1/2 > 120 minutes). The in vitro metabolic instability also manifested in moderate-to-high plasma clearances of the parent compound in rats and dogs with significant concentrations of M1 detected in circulation. Mild heat deactivation of liver microsomes or coincubation with the flavin-containing monooxygenase (FMO) inhibitor imipramine significantly diminished M1 formation. In contrast, oxidative metabolism of compound 1 to M1 was not inhibited by the pan cytochrome P450 inactivator 1-aminobenzotriazole. Incubations with recombinant FMO isoforms (FMO1, FMO3, and FMO5) revealed that FMO1 principally catalyzed the conversion of compound 1 to M1. FMO1 is not expressed in adult human liver, which rationalizes the species difference in oxidative desulfurization. Oxidation by FMO1 followed Michaelis-Menten kinetics with Michaelis-Menten constant, maximum rate of oxidative desulfurization, and intrinsic clearance values of 209 μM, 20.4 nmol/min/mg protein, and 82.7 μl/min/mg protein, respectively. Addition of excess glutathione essentially eliminated the conversion of compound 1 to M1 in NADPH-supplemented rat and dog liver microsomes, which suggests that the initial FMO1-mediated S-oxygenation of compound 1 yields a sulfenic acid intermediate capable of redox cycling to the parent compound in a glutathione-dependent fashion or undergoing further oxidation to a more

  4. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Ai ds (CEF); Scientific Opinion on Flavouring Group Evaluation 208 (FGE.208): Consideration of genotoxicity data on representatives for 10 alicyclic aldehydes with the α , β - unsaturation in ring / side - chain

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Lund, Pia;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to evaluate the genotoxic potential of one flavouring substance from subgroup 2.2 of FGE.19 in the Flavouring Group Evaluation 208. The Flavour Industry has provided....... In order to clarify the genotoxic potential of this substance, the Panel considered that further in vivo testing should be performed. To address this, an in vivo Comet assay, considering the first site of contact (e.g. stomach or duodenum) and liver, should be carried out according to the Scientific Report...

  5. EFSA Panel on Food Contact Material, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 201Rev1: 2-Alkylated, aliphatic, acyclic alpha,beta-unsaturated aldehydes and precursors, with or without additional double-bonds, from chemical subgroup 1

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider in this revision 1 of Flavouring Group Evaluation 201, the additional data on genotoxicity submitted by the Industry on two substances, 2-methylpent-2-enal....... The Panel therefore concluded that further data are required in order to clarify the genotoxic potential of this subgroup. The Panel considers the Comet assay with [FL-no: 05.095] as test material and performed on liver, blood and first site of contact, as a preferred option to further investigate...

  6. Bioaccumulation of Cry1Ab protein from an herbivore reduces anti-oxidant enzyme activities in two spider species.

    Directory of Open Access Journals (Sweden)

    Ji Zhou

    Full Text Available Cry proteins are expressed in rice lines for lepidopteran pest control. These proteins can be transferred from transgenic rice plants to non-target arthropods, including planthoppers and then to a predatory spider. Movement of Cry proteins through food webs may reduce fitness of non-target arthropods, although recent publications indicated no serious changes in non-target populations. Nonetheless, Cry protein intoxication influences gene expression in Cry-sensitive insects. We posed the hypothesis that Cry protein intoxication influences enzyme activities in spiders acting in tri-trophic food webs. Here we report on the outcomes of experiments designed to test our hypothesis with two spider species. We demonstrated that the movement of CryAb protein from Drosophila culture medium into fruit flies maintained on the CryAb containing medium and from the flies to the spiders Ummeliata insecticeps and Pardosa pseudoannulata. We also show that the activities of three key metabolic enzymes, acetylcholine esterase (AchE, glutathione peroxidase (GSH-Px, and superoxide dismutase (SOD were significantly influenced in the spiders after feeding on Cry1Ab-containing fruit flies. We infer from these data that Cry proteins originating in transgenic crops impacts non-target arthropods at the physiological and biochemical levels, which may be one mechanism of Cry protein-related reductions in fitness of non-target beneficial predators.

  7. Analysis of Oxidative Stress Enzymes and Structural and Functional Proteins on Human Aortic Tissue from Different Aortopathies

    Science.gov (United States)

    Soto, María Elena; Soria-Castro, Elizabeth; Guarner Lans, Verónica; Muruato Ontiveros, Eleazar; Iván Hernández Mejía, Benjamín; Jorge Martínez Hernandez, Humberto; Barragán García, Rodolfo; Herrera, Valentín; Pérez-Torres, Israel

    2014-01-01

    The role of oxidative stress in different aortopathies is evaluated. Thirty-two tissue samples from 18 men and 14 women were divided into: 4 control (C) subjects, 11 patients with systemic arterial hypertension (SAH), 4 with variants of Marfan's syndrome (MV), 9 with Marfan's syndrome (M), 2 with Turner's syndrome, and 2 with Takayasu's arteritis (TA). Aorta fragments were homogenized. Lipoperoxidation (LPO), copper-zinc and manganese superoxide dismutase (Mn and Cu-Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), endothelial nitric oxide synthase (eNOS), nitrates and nitrites (NO3−/NO2−), and type IV collagen, and laminin were evaluated. There was an increase in Mn- and Cu-Zn-SOD activity in SAH, MV, M, and Turner's syndrome. There was also an increase in CAT activity in M and Turner' syndrome. GPx and GST activity decreased and LPO increased in all groups. eNOS was decreased in SAH, MV, and M and NO3−/NO2− were increased in SAH and TA. Type IV collagen was decreased in Turner's syndrome and TA. Laminin γ-1 was decreased in MV and increased in M. In conclusion, similarities and differences in oxidative stress in the different aortopathies studied including pathologies with aneurysms were found with alterations in SOD, CAT, GPx, GST, and eNOS activity that modify subendothelial basement membrane proteins. PMID:25101153

  8. Activity-Based Protein Profiling Reveals Mitochondrial Oxidative Enzyme Impairment and Restoration in Diet-Induced Obese Mice

    Energy Technology Data Exchange (ETDEWEB)

    Sadler, Natalie C.; Angel, Thomas E.; Lewis, Michael P.; Pederson, Leeanna M.; Chauvigne-Hines, Lacie M.; Wiedner, Susan D.; Zink, Erika M.; Smith, Richard D.; Wright, Aaron T.

    2012-10-24

    High-fat diet (HFD) induced obesity and concomitant development of insulin resistance (IR) and type 2 diabetes mellitus have been linked to mitochondrial dysfunction. However, it is not clear whether mitochondrial dysfunction is a direct effect of a HFD or if the mitochondrial function is reduced with increased HFD duration. We hypothesized that the function of mitochondrial oxidative and lipid metabolism functions in skeletal muscle mitochondria for HFD mice are similar or elevated relative to standard diet (SD) mice, thereby IR is neither cause nor consequence of mitochondrial dysfunction. We applied a chemical probe approach to identify functionally reactive ATPases and nucleotide-binding proteins in mitochondria isolated from skeletal muscle of C57Bl/6J mice fed HFD or SD chow for 2-, 8-, or 16-weeks; feeding time points known to induce IR. A total of 293 probe-labeled proteins were identified by mass spectrometry-based proteomics, of which 54 differed in abundance between HFD and SD mice. We found proteins associated with the TCA cycle, oxidative phosphorylation (OXPHOS), and lipid metabolism were altered in function when comparing SD to HFD fed mice at 2-weeks, however by 16-weeks HFD mice had TCA cycle, β-oxidation, and respiratory chain function at levels similar to or higher than SD mice.

  9. Analysis of Oxidative Stress Enzymes and Structural and Functional Proteins on Human Aortic Tissue from Different Aortopathies

    Directory of Open Access Journals (Sweden)

    María Elena Soto

    2014-01-01

    Full Text Available The role of oxidative stress in different aortopathies is evaluated. Thirty-two tissue samples from 18 men and 14 women were divided into: 4 control (C subjects, 11 patients with systemic arterial hypertension (SAH, 4 with variants of Marfan’s syndrome (MV, 9 with Marfan’s syndrome (M, 2 with Turner’s syndrome, and 2 with Takayasu’s arteritis (TA. Aorta fragments were homogenized. Lipoperoxidation (LPO, copper-zinc and manganese superoxide dismutase (Mn and Cu-Zn-SOD, catalase (CAT, glutathione peroxidase (GPx, glutathione S-transferase (GST, endothelial nitric oxide synthase (eNOS, nitrates and nitrites (NO3−/NO2−, and type IV collagen, and laminin were evaluated. There was an increase in Mn- and Cu-Zn-SOD activity in SAH, MV, M, and Turner’s syndrome. There was also an increase in CAT activity in M and Turner’ syndrome. GPx and GST activity decreased and LPO increased in all groups. eNOS was decreased in SAH, MV, and M and NO3−/NO2− were increased in SAH and TA. Type IV collagen was decreased in Turner’s syndrome and TA. Laminin γ-1 was decreased in MV and increased in M. In conclusion, similarities and differences in oxidative stress in the different aortopathies studied including pathologies with aneurysms were found with alterations in SOD, CAT, GPx, GST, and eNOS activity that modify subendothelial basement membrane proteins.

  10. The roles of aldehyde dehydrogenases (ALDHs in the PDH bypass of Arabidopsis

    Directory of Open Access Journals (Sweden)

    Lin Ming

    2009-03-01

    Full Text Available Abstract Background Eukaryotic aldehyde dehydrogenases (ALDHs, EC 1.2.1, which oxidize aldehydes into carboxylic acids, have been classified into more than 20 families. In mammals, Family 2 ALDHs detoxify acetaldehyde. It has been hypothesized that plant Family 2 ALDHs oxidize acetaldehyde generated via ethanolic fermentation, producing acetate for acetyl-CoA biosynthesis via acetyl-CoA synthetase (ACS, similar to the yeast pathway termed the "pyruvate dehydrogenase (PDH bypass". Evidence for this pathway in plants has been obtained from pollen. Results To test for the presence of the PDH bypass in the sporophytic tissue of plants, Arabidopsis plants homozygous for mutant alleles of all three Family 2 ALDH genes were fed with 14C-ethanol along with wild type controls. Comparisons of the incorporation rates of 14C-ethanol into fatty acids in mutants and wild type controls provided direct evidence for the presence of the PDH bypass in sporophytic tissue. Among the three Family 2 ALDHs, one of the two mitochondrial ALDHs (ALDH2B4 appears to be the primary contributor to this pathway. Surprisingly, single, double and triple ALDH mutants of Arabidopsis did not exhibit detectable phenotypes, even though a Family 2 ALDH gene is required for normal anther development in maize. Conclusion The PDH bypass is active in sporophytic tissue of plants. Blocking this pathway via triple ALDH mutants does not uncover obvious visible phenotypes.

  11. Inhibitory potential of ginger extracts against enzymes linked to type 2 diabetes, inflammation and induced oxidative stress.

    Science.gov (United States)

    Rani, M Priya; Padmakumari, K P; Sankarikutty, B; Cherian, O Lijo; Nisha, V M; Raghu, K G

    2011-03-01

    Ginger (Zingiber officinale Roscoe) continues to be used as an important cooking spice and herbal medicine around the world. Gingerols, the major pungent components of ginger, are known to improve diabetes, including the effect of enhancement against insulin sensitivity. In the current study, ginger sequentially extracted with different solvents-namely, hexane, ethyl acetate, methanol, 70% methanol-water and water-were screened to determine the variations in phenolic-linked active constituents. The potential of these extracts to inhibit key enzymes relevant to type 2 diabetes and inflammation was studied. Phenolic compounds-namely, gingerols and shoagols-were quantified using high-performance liquid chromatography. Ethyl acetate extract showed higher activity compared with other extracts. These studies indicate that ginger has very good potential for α-glucosidase and α-amylase inhibition relevant for type 2 diabetes management and cyclooxygenase inhibition for inflammation. PMID:20874376

  12. Effect of different methods of hypoxic exercise training on free radical oxidation and antioxidant enzyme activity in the rat brain.

    Science.gov (United States)

    Li, Jie; Wang, Yuxia

    2013-11-01

    The effects of different modes of hypoxic exercise training on free radical production and antioxidant enzyme activity in the brain of rats were investigated in this study. A total of 40 healthy 2-month-old male Wister rats were randomly assigned to 5 groups according to different training modes. Endurance training sessions were performed for 5 weeks under different normoxic (atmospheric pressure ~632 mmHg, altitude ~1,500 m) and hypoxic conditions (atmospheric pressure ~493 mmHg, altitude ~3,500 m) at the same relative intensity. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activity and the malondialdehyde (MDA) content of the brain were evaluated by spectrophotometric analysis. Compared to the low-training low (LL) group, the SOD activity was significantly increased by 68.73, 54.28 and 304.02% in the high-training high (HH), high-training low (HL) and high-exercise high-training low (HHL) groups, respectively. However, no obvious change was observed for the low-training high (LH) group. In comparison to the LL group, the GSH-Px activity was found to be significantly higher in the HH, HL, LH and HHL groups. Similarly, in comparison to the LL group, the CAT activity exhibited a significant increase in the HH, HL, LH and HHL groups. Compared to the LL group, the MDA content was significantly increased in the HH, HL and HHL groups, although no significant difference was detected for the LH group. Following exhaustive exercise, the antioxidant enzyme activities in the rat brains were immediately improved in all the hypoxia modes. Moreover, the free radical production was increased after all the modes of hypoxic exercise training, with the LH mode being the only exception. PMID:24649054

  13. Effect of different methods of hypoxic exercise training on free radical oxidation and antioxidant enzyme activity in the rat brain

    Science.gov (United States)

    LI, JIE; WANG, YUXIA

    2013-01-01

    The effects of different modes of hypoxic exercise training on free radical production and antioxidant enzyme activity in the brain of rats were investigated in this study. A total of 40 healthy 2-month-old male Wister rats were randomly assigned to 5 groups according to different training modes. Endurance training sessions were performed for 5 weeks under different normoxic (atmospheric pressure ~632 mmHg, altitude ~1,500 m) and hypoxic conditions (atmospheric pressure ~493 mmHg, altitude ~3,500 m) at the same relative intensity. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activity and the malondialdehyde (MDA) content of the brain were evaluated by spectrophotometric analysis. Compared to the low-training low (LL) group, the SOD activity was significantly increased by 68.73, 54.28 and 304.02% in the high-training high (HH), high-training low (HL) and high-exercise high-training low (HHL) groups, respectively. However, no obvious change was observed for the low-training high (LH) group. In comparison to the LL group, the GSH-Px activity was found to be significantly higher in the HH, HL, LH and HHL groups. Similarly, in comparison to the LL group, the CAT activity exhibited a significant increase in the HH, HL, LH and HHL groups. Compared to the LL group, the MDA content was significantly increased in the HH, HL and HHL groups, although no significant difference was detected for the LH group. Following exhaustive exercise, the antioxidant enzyme activities in the rat brains were immediately improved in all the hypoxia modes. Moreover, the free radical production was increased after all the modes of hypoxic exercise training, with the LH mode being the only exception. PMID:24649054

  14. Effects of small peptides, probiotics, prebiotics, and synbiotics on growth performance, digestive enzymes, and oxidative stress in orange-spotted grouper, Epinephelus coioides, juveniles reared in artificial seawater

    Science.gov (United States)

    Wang, Tao; Cheng, Yongzhou; Chen, Xiaoyan; Liu, Zhaopu; Long, Xiaohua

    2016-04-01

    Aquaculture production efficiency may increase by using feed additives. This study investigated the effects of diff erent dietary additives [w/w: 2% small peptides, 0.01% probiotics (Bacillus licheniformis) and 0.2% prebiotics (inulin)] on growth performance, digestive enzyme activities, and oxidative stress in juvenile Epinephelus coioides reared in artificial seawater of two salt concentrations (13.5 vs. 28.5). Weight gain rate was significantly higher in fish fed the diet supplemented with small peptides, B. licheniformis, inulin, or synbiotics than that in fish fed the basal diet; the greatest weight gain rate was found in fish fed the small peptide treatment [56.0% higher than basal diet]. Higher feed efficiency was detected in fish fed the diet supplemented with small peptides than that of fish in the other dietary treatments. Total protease activity in the stomach and intestines was highest in fish fed the small peptide-treated diet, whereas lipase activity was highest in those fed synbiotics (combination of Bacillus licheniformis and inulin) than that in fish fed the other treatments. Antioxidant enzyme (total superoxide dismutase and catalase) activities and hepatic malondialdehyde content were higher in fish receiving the dietary supplements and maintained in artificial seawater containing 13.5 salinity compared with those in the control (28.5). Hepatic catalase activity in grouper fed the diets with small peptides or synbiotics decreased significantly compared with that in control fish. Overall, the three types of additives improved growth rate of juvenile grouper and digestive enzymes activities to varying degrees but did not effectively improve antioxidant capacity under low-salinity stress conditions.

  15. Changes of the activities of glycolytic and oxidative enzymes before and after slaughter in the longissimus muscle of Pietrain and Duroc pigs and a Duroc-Pietrain crossbreed.

    Science.gov (United States)

    Werner, C; Natter, R; Wicke, M

    2010-12-01

    After slaughter of pigs, the pH of the meat decreases due to lactate accumulation within the tissue. In addition to calcium homeostasis, energy metabolism plays a key role during the muscle-to-meat transition, and it is interesting to know how specific enzymes of the glycolytic and oxidative pathways change during this process, especially in relation to the antemortem situation, and if there is an impact of these alterations on the meat quality characteristics. Therefore, in the present study samples of the LM from the pig genetic groups Pietrain (Pi), Duroc (Du), and a Du × Pi crossbreed population (DuPi) were collected 24 h before as well as 1 min, 40 min, and 12 h after slaughter, and the activities of the glycogen phosphorylase (GP), phosphofructokinase (PFK), lactate dehydrogenase (LDH), citrate synthase (CS), NADH-ubiquinone oxidoreductase (complex I), and cytochrome oxidase were analyzed. Additional investigations include carcass and meat quality characteristics as well as the microstructure of the LM. The Pi breed had greater (P meat values, but no differences (P > 0.05) of the meat quality traits could be determined between the investigated pig breeds. The Pi pigs exhibited a greater (P after slaughter (1 min postmortem) of the pigs and the activity of the LDH within 40 min postmortem. After 12 h, the GP, PFK, LDH, and complex I activities decreased to the amount of the preslaughter sample. No differences could be found with regard to the enzyme activities of the CS and cytochrome oxidase at all determination times. Considering the enzyme activities within the different breeds, the Pi pigs exhibited greater (P animals exhibited greater (P meat transition process after slaughter of the animals without an impact on the muscle quality. The activities of the GP, PFK, CS, and complex I reflect the differences of the muscle fiber composition between the Pi and Du pigs.

  16. Exercise-induced oxidative stress and antioxidant enzyme activity in type 2 diabetic patients with and without diastolic dysfunction and hypertension

    Directory of Open Access Journals (Sweden)

    Kostić Nada

    2009-01-01

    Full Text Available Introduction. Antioxidant systems are important factors affecting the oxidation of lipoproteins and thereby the progression of atherosclerotic disease. It has been suggested that physical activity might maintain and promote the antioxidant defence capacity against the oxidative stress. Left ventricular dysfunction (LVDD and hypertension are more common in subjects with diabetes mellitus (DM type 2. Objective. To evaluate the oxidative stress in patients with DM type 2, particularly with LVDD and hypertension and to determine the influence of acute exercise training on the investigated parameters. Methods. To assess the oxidative stress of patients, we determined the following antioxidative parameters: triglycerides (TG, total cholesterol, low density cholesterol, OxLDL cholesterol, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, plasminogen activator-type 1 (PAI-1 which were measured at rest and immediately after the acute bout of the cardiopulmonary exercise cycle ergometer test. Results. In basal conditions, diabetic patients had a significant increase of TG (3.12±1.09 vs 1.74±0.9 mmol/l; p<0.01, OxLDL cholesterol (84.73±16.9 vs 79.00±29.26 mmol/l; p<0.05 and SOD enzyme activity (913.38±120.36 vs 877.14 ±153.18; p<0.05 compared to controls. During the acute exercise test, there were significantly greater levels of OxLDL (84.73±16.90 vs 92.33±23.29 mmol/l; p<0.05 in study patients. SOD significantly increased in both groups during exercise, in diabetic patients (913.38±120.36 vs 921.50±130.03 U/g Hb; p<0.05 and in controls (877.14±153.18 vs 895.00±193.49 U/g Hb; p<0.05. GSH-Px significantly increased only in diabetic patients after acute exercise (45.04±11.19 vs 51.81±15.07 U/g Hb; p<0.01, but not in controls. PAI significantly decreased during the exercise test only in healthy subjects (2.60±0.35 vs 2.22±0.65; p<0.05. Type 2 diabetic patients with cardiovascular complications (LVDD and hypertension had a significant

  17. Impact of L-FABP and glucose on polyunsaturated fatty acid induction of PPARα-regulated β-oxidative enzymes

    OpenAIRE

    Petrescu, Anca D.; Huang, Huan; Martin, Gregory G.; McIntosh, Avery L.; Storey, Stephen M.; Landrock, Danilo; Kier, Ann B.; Schroeder, Friedhelm

    2012-01-01

    Liver fatty acid binding protein (L-FABP) is the major soluble protein that binds very-long-chain n-3 polyunsaturated fatty acids (n-3 PUFAs) in hepatocytes. However, nothing is known about L-FABP's role in n-3 PUFA-mediated peroxisome proliferator activated receptor-α (PPARα) transcription of proteins involved in long-chain fatty acid (LCFA) β-oxidation. This issue was addressed in cultured primary hepatocytes from wild-type, L-FABP-null, and PPARα-null mice with these major findings: 1) PUF...

  18. Cardiovascular diseases: oxidative damage and antioxidant protection.

    Science.gov (United States)

    Zhang, P-Y; Xu, X; Li, X-C

    2014-10-01

    Atherosclerosis, the hardening of arteries under oxidative stress is related to oxidative changes of low density lipoproteins (LDL). The antioxidants prevent the formation of oxidized LDL during atherogenesis. Perhaps more than one mechanism is involved in the atherosclerosis disease where LDL is oxidized in all the cells of arterial wall during the development of this disease. The oxidation of LDL produces lipid peroxidation products such as isoprostans from arachidonic, eicosapentaenoic and docosahexaenoic acids, oxysterols from cholesterol, hydroxyl fatty acids, lipid peroxides and aldehydes. The lipid peroxidation bioassay can serve as a marker for the risk of cardiovascular. An in vivo test of levels of oxidative lipid damage is an early prediction of development of cardiovascular disease (CVD). Serum paraoxonase (PON) activity is correlated to severity of the coronary artery disease. The antioxidants level in the serum and serum paraoxonase activity provides information for the risk of CVD. The antioxidant enzyme superoxide dismutase is responsible for dismutation of superoxide, a free radical chain initiator. The subcellular changes in the equilibrium in favor of free radicals can cause increase in the oxidative stress which leads to cardiomyopathy, heart attack or cardiac dysfunction. The oxidative damage and defense of heart disease has been reported where dietary antioxidants protect the free radical damage to DNA, proteins and lipids. The ascorbic acid, vitamin C is an effective antioxidant and high vitamin E intake can reduce the risk of coronary heart disease (CHD) by inhibition of atherogenic forms of oxidized LDL. The vitamin A and beta-carotene protect lipid peroxidation and provitamin-A activity. It has been recently suggested that the protection of oxidative damage and related CVD is best served by antioxidants found in the fruits and vegetables. The oxidative damage and antioxidant protection of CVD have been described here. PMID:25392110

  19. Chemical trapping of labile aldehyde intermediates in the metabolism of propranolol and oxprenolol.

    Science.gov (United States)

    Goldszer, F; Tindell, G L; Walle, U K; Walle, T

    1981-11-01

    Propranolol is N-dealkylated to N-desisopropylpropranolol (DIP) by microsomal enzymes. DIP was shown in this study to be rapidly deaminated by monoamine oxidase (MAO). Thus, incubation of DIP (10(-4) M) with rat liver mitochondria for 90 min demonstrated 74.8 +/- 4.1% metabolism which was almost completely blocked by the MAO inhibitor pargyline (10(-5) M). The end products of this deamination were 3-(alpha-naphthoxy)-1,2-propylene glycol (Glycol) and 3-(alpha-naphthoxy)lactic acid (NLA). In the presence of excess NADH the Glycol was the major product whereas NLA was the major product in the presence of excess NAD+. The intermediate aldehyde in this deamination reaction, 3-(alpha-naphthoxy)-2-hydroxypropanal (Ald), was extremely labile and decomposed quantitatively to alpha-naphthol when removed from the incubates. However, the addition of methoxyamine hydrochloride directly to the incubates made it possible to chemically trap the intact Ald as an O-methyloxime and prove its structure by gas chromatography-mass spectrometry. The deamination of the primary amine of oxprenolol also gave rise to a labile aldehyde which could be trapped and identified as its O-methyloxime. PMID:7335950

  20. An electric detection of immunoglobulin G in the enzyme-linked immunosorbent assay using an indium oxide nanoparticle ion-sensitive field-effect transistor

    Science.gov (United States)

    Lee, Dongjin; Cui, Tianhong

    2012-01-01

    Semiconducting nanoparticle ion-sensitive field-effect transistors (ISFETs) are used to detect immunoglobulin G (IgG) in the conventional enzyme-linked immunosorbent assay (ELISA). Indium oxide and silica nanoparticles were layer-by-layer self-assembled with the oppositely charged polyelectrolyte as the electrochemical transducer and antibody immobilization site, respectively. The assay was conducted on a novel platform of indium oxide nanoparticle ISFETs, where the electric signals are generated in response to the concentration of target IgG using the labeled detecting antibody. The sandwiched ELISA structure catalyzed the conversion of the acidic substrate into neutral substance with the aid of horseradish peroxidase. The pH change in the substrate solution was detected by nanoparticle ISFETs. Normal rabbit IgG was used as a model antigen whose detection limit of 0.04 ng ml-1 was found. The facile electric detection in the conventional assay through the semiconducting nanoparticle ISFET has potential applications as a point-of-care detection or a sensing element in a lab-on-a-chip system.

  1. In vitro antidiabetic and inhibitory potential of turmeric (Curcuma longa L) rhizome against cellular and LDL oxidation and angiotensin converting enzyme.

    Science.gov (United States)

    Lekshmi, P C; Arimboor, Ranjith; Nisha, V M; Menon, A Nirmala; Raghu, K G

    2014-12-01

    Turmeric (Curcuma longa L) rhizome extracts were evaluated for their antidiabetic, antihypertensive and antioxidant potentials. α-Glucosidase (0.4 μg/mL) and α-amylase (0.4 μg/mL) inhibitory potential of turmeric ethyl acetate extract was significantly higher than those of the reference drug acarbose (17.1 μg/mL and 290.6 μg/mL respectively). Protein glycation inhibitory potential of ethyl acetate extract was 800 times higher than that of ascorbic acid. High potential of ethyl acetate extract to scavenge free radicals and to reduce LDL oxidation and cellular oxidative stress was also revealed. The positive correlation obtained between the free radical scavenging capacity of the extracts and their antiglycation potential further confirmed the role of antioxidants in controlling glycation reactions. Ethyl acetate extract was also found as effective in reducing hypertension by inhibiting angiotensin converting enzyme (ACE). Antidiabetic, ACE inhibitory and antioxidant capacities of the extracts were in the order of their curcumin contents.

  2. Antioxidant-enzyme reaction to the oxidative stress due to alpha-cypermethrin, chlorpyriphos, and pirimicarb in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Chahid, Karim; Laglaoui, Amin; Zantar, Said; Ennabili, Abdeslam

    2015-11-01

    Tomato (Lycopersicon esculentum Mill.) becomes one of the world's foremost vegetables, and its world production and consumption have increased fairly quickly. The capacity to induce oxidative stress in tomato plant, exposed to three xenobiotics such as alpha-cypermethrin, chlorpyriphos, and pirimicarb, was investigated by the evaluation of lipid peroxidation by measuring malondialdehyde (MDA) rate; also, we studied the response of tomato to this stress by assessing the response of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), glutathione-s-transferase (GST), and glutathione reductase (GR). The effect of the insecticides was observed using four concentrations (25, 50, 75, and 100%) for germinating seeds and only the recommended concentration in agriculture (100%) for growing plants. Our results show an important accumulation of MDA, demonstrating the increase of lipid peroxidation in consequence of the excessive reactive oxygen species (ROS) production due to insecticide treatment. In response to this oxidative stress in tomato seedlings and plants, the activities of antioxidant-enzyme system were generally enhanced. The electrophoretic analysis showed also the apparition of new isoenzymes as the case for CAT and POD.

  3. An electric detection of immunoglobulin G in the enzyme-linked immunosorbent assay using an indium oxide nanoparticle ion-sensitive field-effect transistor

    International Nuclear Information System (INIS)

    Semiconducting nanoparticle ion-sensitive field-effect transistors (ISFETs) are used to detect immunoglobulin G (IgG) in the conventional enzyme-linked immunosorbent assay (ELISA). Indium oxide and silica nanoparticles were layer-by-layer self-assembled with the oppositely charged polyelectrolyte as the electrochemical transducer and antibody immobilization site, respectively. The assay was conducted on a novel platform of indium oxide nanoparticle ISFETs, where the electric signals are generated in response to the concentration of target IgG using the labeled detecting antibody. The sandwiched ELISA structure catalyzed the conversion of the acidic substrate into neutral substance with the aid of horseradish peroxidase. The pH change in the substrate solution was detected by nanoparticle ISFETs. Normal rabbit IgG was used as a model antigen whose detection limit of 0.04 ng ml−1 was found. The facile electric detection in the conventional assay through the semiconducting nanoparticle ISFET has potential applications as a point-of-care detection or a sensing element in a lab-on-a-chip system

  4. Effects of tributyltin (TBT) on enzyme activity and oxidative stress in hepatopancreas and hemolymph of small abalone, Haliotis diversicolor supertexta

    Institute of Scientific and Technical Information of China (English)

    Jia Xiwei; Zhang Ziping; Wang Shuhong; Lin Peng; Zou Zhihua; Huang Bangqin; Wang Yilei

    2009-01-01

    We investigated the effect of tributyltin (TBT) exposure on the concentration of malondialdehyde (MDA) and the activity levels of the superoxide dismutase (SOD), catalase (CAT), and acid and alkaline phosphatase (ACP and AKP) enzymes in the small abalone, Haliotis diversicolor supertexta. We collected samples of the hepatopancreas and hemolymph 2, 6, 24, 48, 96, and 192 h after exposure to 0.35μg (Sn)/L TBT. In the hepatopancreas, ACP activity was significantly higher in animals exposed to TBT 2, 24, and 96 h post-exposure compared with the control animals. AKP activity was also higher after 2 h, but SOD and CAT activity was unchanged. The concentration of MDA in the hemolymph was significantly higher than the control animals 2 and 6 h post-exposure. In the hemolymph of animals exposed to TBT, ACP activity was significantly lower than in the control animals 192 h post-exposure, whereas AKP activity was significantly lower 2 and 192 h post-exposure. Hemolymph SOD activity and levels of MDA were significantly lower than in the control animals 24 h after exposure but significantly higher after 96 h. Our results demonstrate that exposure to TBT cause rapid changes in ACP and AKP activity as well as altering the concentration of MDA in the hepatopancreas and hemolymph. SOD and CAT do not appear to be involved in the detoxification of TBT in the hepatopancreas of small abalone.

  5. Enzyme mimics of spinel-type CoxNi1−xFe2O4 magnetic nanomaterial for eletroctrocatalytic oxidation of hydrogen peroxide

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Spinel-type CoxNi1−xFe2O4 (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) were synthesized. •CoxNi1−xFe2O4 were first employed as novel enzyme mimic sensing materials of H2O2. •Co0.5Ni0.5Fe2O4/CPE showed excellent electrocatalytic activity to H2O2. •Co0.5Ni0.5Fe2O4/CPE was successfully applied to determine H2O2 in toothpastes. -- Abstract: A series of spinel-type CoxNi1−xFe2O4 (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1.0) magnetic nanomaterials were solvothermally synthesized as enzyme mimics for the eletroctrocatalytic oxidation of H2O2. X-ray diffraction and scanning electron microscope were employed to characterize the composition, structure and morphology of the material. The electrochemical properties of spinel-type CoxNi1−xFe2O4 with different (Co/Ni) molar ratio toward H2O2 oxidation were investigated, and the results demonstrated that Co0.5Ni0.5Fe2O4 modified carbon paste electrode (Co0.5Ni0.5Fe2O4/CPE) possessed the best electrocatalytic activity for H2O2 oxidation. Under optimum conditions, the calibration curve for H2O2 determination on Co0.5Ni0.5Fe2O4/CPE was linear in a wide range of 1.0 × 10−8–1.0 × 10−3 M with low detection limit of 3.0 × 10−9 M (S/N = 3). The proposed Co0.5Ni0.5Fe2O4/CPE was also applied to the determination of H2O2 in commercial toothpastes with satisfactory results, indicating that CoxNi1−xFe2O4 is a promising hydrogen peroxidase mimics for the detection of H2O2

  6. Effect of mild-to-moderate smoking on viral load, cytokines, oxidative stress, and cytochrome P450 enzymes in HIV-infected individuals.

    Directory of Open Access Journals (Sweden)

    Anusha Ande

    Full Text Available Mild-to-moderate tobacco smoking is highly prevalent in HIV-infected individuals, and is known to exacerbate HIV pathogenesis. The objective of this study was to determine the specific effects of mild-to-moderate smoking on viral load, cytokine production, and oxidative stress and cytochrome P450 (CYP pathways in HIV-infected individuals who have not yet received antiretroviral therapy (ART. Thirty-two human subjects were recruited and assigned to four different cohorts as follows: a HIV negative non-smokers, b HIV positive non-smokers, c HIV negative mild-to-moderate smokers, and d HIV positive mild-to-moderate smokers. Patients were recruited in Cameroon, Africa using strict selection criteria to exclude patients not yet eligible for ART and not receiving conventional or traditional medications. Those with active tuberculosis, hepatitis B or with a history of substance abuse were also excluded. Our results showed an increase in the viral load in the plasma of HIV positive patients who were mild-to-moderate smokers compared to individuals who did not smoke. Furthermore, although we did not observe significant changes in the levels of most pro-inflammatory cytokines, the cytokine IL-8 and MCP-1 showed a significant decrease in the plasma of HIV-infected patients and smokers compared with HIV negative non-smokers. Importantly, HIV-infected individuals and smokers showed a significant increase in oxidative stress compared with HIV negative non-smoker subjects in both plasma and monocytes. To examine the possible pathways involved in increased oxidative stress and viral load, we determined the mRNA levels of several antioxidant and cytochrome P450 enzymes in monocytes. The results showed that the levels of most antioxidants are unaltered, suggesting their inability to counter oxidative stress. While CYP2A6 was induced in smokers, CYP3A4 was induced in HIV and HIV positive smokers compared with HIV negative non-smokers. Overall, the findings suggest

  7. Oxidative stress in deep scattering layers: Heat shock response and antioxidant enzymes activities of myctophid fishes thriving in oxygen minimum zones

    Science.gov (United States)

    Lopes, Ana Rita; Trübenbach, Katja; Teixeira, Tatiana; Lopes, Vanessa M.; Pires, Vanessa; Baptista, Miguel; Repolho, Tiago; Calado, Ricardo; Diniz, Mário; Rosa, Rui

    2013-12-01

    Diel vertical migrators, such as myctophid fishes, are known to encounter oxygen minimum zones (OMZ) during daytime in the Eastern Pacific Ocean and, therefore, have to cope with temperature and oxidative stress that arise while ascending to warmer, normoxic surface waters at night-time. The aim of this study was to investigate the antioxidant defense strategies and heat shock response (HSR) in two myctophid species, namely Triphoturus mexicanus and Benthosema panamense, at shallow and warm surface waters (21 kPa, 20-25 °C) and at hypoxic, cold (≤1 kPa, 10 °C) mesopelagic depths. More specifically, we quantified (i) heat shock protein concentrations (HSP70/HSC70) (ii) antioxidant enzyme activities [including superoxide dismutase (SOD), catalase (CAT) and glutathione-S-transferase (GST)], and (iii) lipid peroxidation [malondialdehyde (MDA) levels]. HSP70/HSC70 levels increased in both myctophid species at warmer, well-oxygenated surface waters probably to prevent cellular damage (oxidative stress) due to increased oxygen demand under elevated temperatures and reactive oxygen species (ROS) formation. On the other hand, CAT and GST activities were augmented under hypoxic conditions, probably as preparatory response to a burst of oxyradicals during the reoxygenation phase (while ascending). SOD activity decreased under hypoxia in B. panamense, but was kept unchanged in T. mexicanus. MDA levels in B. panamense did not change between the surface and deep-sea conditions, whereas T. mexicanus showed elevated MDA and HSP70/HSC70 concentrations at warmer surface waters. This indicated that T. mexicanus seems to be not so well tuned to temperature and oxidative stress associated to diel vertical migrations. The understanding of such physiological strategies that are linked to oxygen deprivation and reoxygenation phases may provide valuable information about how different species might respond to the impacts of environmental stressors (e.g. expanding mesopelagic hypoxia

  8. Climate change (elevated CO{sub 2}, elevated temperature and moderate drought) triggers the antioxidant enzymes' response of grapevine cv. Tempranillo, avoiding oxidative damage

    Energy Technology Data Exchange (ETDEWEB)

    Salazar-Parra, C.; Aguirreolea, J.; Sanchez-Diaz, M.; Irigoyen, J.J.; Morales, F. (Departamento de Biologia Vegetal, Seccion Biologia Vegetal (Unidad Asociada al CSIC, EEAD, Zaragoza e ICVV, Logrono), Facultades de Ciencias y Farmacia, Universidad de Navarra, Pamplona (Spain))

    2012-07-01

    Photosynthetic carbon fixation (A{sub N}) and photosynthetic electron transport rate (ETR) are affected by different environmental stress factors, such as those associated with climate change. Under stress conditions, it can be generated an electron excess that cannot be consumed, which can react with O{sub 2}, producing reactive oxygen species. This work was aimed to evaluate the influence of climate change (elevated CO{sub 2}, elevated temperature and moderate drought) on the antioxidant status of grapevine (Vitis vinifera) cv. Tempranillo leaves, from veraison to ripeness. The lowest ratios between electrons generated (ETR) and consumed (A{sub N} + respiration + photorespiration) were observed in plants treated with elevated CO{sub 2} and elevated temperature. In partially irrigated plants under current ambient conditions, electrons not consumed seemed to be diverted to alternative ways. Oxidative damage to chlorophylls and carotenoids was not observed. However, these plants had increases in thiobarbituric acid reacting substances, an indication of lipid peroxidation. These increases matched well with an early rise of H{sub 2}O{sub 2} and antioxidant enzyme activities, superoxide dismutase (EC 1.15.1.1), ascorbate peroxidase (EC 1.11.1.11) and catalase (EC 1.11.1.6). Enzymatic activities were maintained high until ripeness. In conclusion, plants grown under current ambient conditions and moderate drought were less efficient to cope with oxidative damage than well-irrigated plants, and more interestingly, plants grown under moderate drought but treated with elevated CO{sub 2} and elevated temperature were not affected by oxidative damage, mainly because of higher rates of electrons consumed in photosynthetic carbon fixation. (Author)

  9. Genetic inactivation of mitochondria-targeted redox enzyme p66ShcA preserves neuronal viability and mitochondrial integrity in response to oxidative challenges

    Directory of Open Access Journals (Sweden)

    Michael eForte

    2012-07-01

    Full Text Available Mitochondria are essential to neuronal viability and function due to their roles in ATP production, intracellular calcium regulation, and activation of apoptotic pathways. Accordingly, mitochondrial dysfunction has been indicated in a wide variety of neurodegenerative diseases, including Alzheimer’s disease, Huntington’s disease, amyotrophic lateral sclerosis, stroke and multiple sclerosis (MS. Recent evidence points to the permeability transition pore (PTP as a key player in mitochondrial dysfunction in these diseases, in which pathologic opening leads to mitochondrial swelling, rupture, release of cytochrome c, and neuronal death. Reactive oxygen species (ROS, which are inducers of PTP opening, have been prominently implicated in the progression of many of these neurodegenerative diseases. In this context, inactivation of a mitochondria-targeted redox enzyme p66ShcA (p66 has been recently shown to prevent the neuronal cell death leading to axonal severing in the murine model of MS, experimental autoimmune encephalomyelitis (EAE. To further characterize the response of neurons lacking p66, we assessed their reaction to treatment with oxidative stressors implicated in neurodegenerative pathways. Specifically, p66-knockout (p66-KO and wild-type (WT neurons were treated with hydrogen peroxide (H2O2 and nitric oxide (NO, and assessed for cell viability and changes in mitochondrial properties, including morphology and ROS production. The results showed that p66-KO neurons had greater survival following treatment with oxidative stressors and generated less ROS when compared to WT neurons. Correspondingly, mitochondria in p66-KO neurons showed diminished morphological changes in response to these challenges. Overall, these findings highlight the importance of developing mitochondria-targeted therapeutics for neurodegenerative disorders, and emphasize p66, mitochondrial ROS, and the PTP as key targets for maintaining mitochondrial and neuronal

  10. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 208 Revision 1 (FGE.208Rev1): Consideration of genotoxicity data on representatives for 10 alicyclic aldehydes with the a,b-unsaturation in ring

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Nørby, Karin Kristiane

    The EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids was requested to evaluate the genotoxic potential of flavouring substances from subgroup 2.2 of FGE.19 in the Flavouring Group Evaluation 208 Revision 1 (FGE.208Rev1). The Flavour Industry has provided additional...... genotoxicity studies on p-mentha-1,8-dien-7-al [FL-no: 05.117], the representative substance for FGE.19 subgroup 2.2. This substance was tested in vivo in a combined micronucleus assay in bone marrow and Comet assay in liver and duodenum. It did not induce any increase in micronucleated polychromatic...... erythrocytes of the bone marrow of male rats in the micronucleus test and it did not induce DNA damage in duodenum of the same animals as analysed by the Comet assay. The Comet assay performed in liver shows a positive result and therefore the Panel concluded that p-mentha-1,8-dien-7-al [FL-no: 05...

  11. Tunable Ether Production via Coupling of Aldehydes or Aldehyde/Alcohol over Hydrogen-Modified Gold Catalysts at Low Temperatures.

    Science.gov (United States)

    Pan, Ming; Brush, Adrian J; Dong, Guangbin; Mullins, C Buddie

    2012-09-01

    Ethers are an important group of organic compounds that are primarily prepared via homogeneous catalysis, which can lead to operational and environmental issues. Here we demonstrate the production of ethers via heterogeneous catalysis over H adatom-covered gold at temperatures lower than 250 K. Symmetrical ethers can be formed via a self-coupling reaction of corresponding aldehydes; for example, homocoupling of acetaldehyde and propionaldehyde yields diethyl ether and di-n-propyl ether, respectively. In addition, coupling reactions between alcohols and aldehydes, with different carbon chain lengths, are observed via the production of the corresponding unsymmetrical ethers. A reaction mechanism is proposed, suggesting that an alcohol-like intermediate via partial hydrogenation of aldehydes on the surface plays a key role in these reactions. These surface chemical reactions suggest possible heterogeneous routes to low-temperature production of ethers. PMID:26292142

  12. Kunstige Enzymer

    DEFF Research Database (Denmark)

    Bols, Mikael; Bjerre, Jeannette; Marinescu, Lavinia

    2007-01-01

    Enzymer har en enestående evne til at accelerere kemiske processer. Der forskes målrettet i at optimere enzymer baseret på cyclodextrin.......Enzymer har en enestående evne til at accelerere kemiske processer. Der forskes målrettet i at optimere enzymer baseret på cyclodextrin....

  13. Expression of betaine aldehyde dehydrogenase gene and salinity tolerance in rice transgenic plants

    Institute of Scientific and Technical Information of China (English)

    郭岩; 张莉; 肖岗; 曹守云; 谷冬梅; 田文忠; 陈受宜

    1997-01-01

    Betaine as one of osmolytes plays an important role in osmoregulation of most high plants. Betaine aldehyde dehydrogenase C BADH) is the second enzyme involved in betaine biosynthesis. The BADH gene from a halophite, Atriplex hortensis, was transformed into rice cultivars by bombarment method. Totally 192 transgenic rice plants were obtained and most of them had higher salt tolerance than controls. Among transgenic plants transplanted in the saline pool containing 0.5% NaCl in a greenhouse, 22 survived, 13 of which set seeds, and the frequency of seed setting was very low, only 10% . But the controls could not grow under the same condition. The results of BADH ac-tivity assay and Northern blot showed that the BADH gene was integrated into chromosomes of transgenic plants and expressed.

  14. Aldehyde dehydrogenase 1a1 mediates a GABA synthesis pathway in midbrain dopaminergic neurons.

    Science.gov (United States)

    Kim, Jae-Ick; Ganesan, Subhashree; Luo, Sarah X; Wu, Yu-Wei; Park, Esther; Huang, Eric J; Chen, Lu; Ding, Jun B

    2015-10-01

    Midbrain dopamine neurons are an essential component of the basal ganglia circuitry, playing key roles in the control of fine movement and reward. Recently, it has been demonstrated that γ-aminobutyric acid (GABA), the chief inhibitory neurotransmitter, is co-released by dopamine neurons. Here, we show that GABA co-release in dopamine neurons does not use the conventional GABA-synthesizing enzymes, glutamate decarboxylases GAD65 and GAD67. Our experiments reveal an evolutionarily conserved GABA synthesis pathway mediated by aldehyde dehydrogenase 1a1 (ALDH1a1). Moreover, GABA co-release is modulated by ethanol (EtOH) at concentrations seen in blood alcohol after binge drinking, and diminished ALDH1a1 leads to enhanced alcohol consumption and preference. These findings provide insights into the functional role of GABA co-release in midbrain dopamine neurons, which may be essential for reward-based behavior and addiction.

  15. Trimethylamine oxide, betaine and other osmolytes in deep-sea animals: depth trends and effects on enzymes under hydrostatic pressure.

    Science.gov (United States)

    Yancey, P H; Rhea, M D; Kemp, K M; Bailey, D M

    2004-06-01

    Most shallow teleosts have low organic osmolyte contents, e.g. 70 mmol/kg or less of trimethylamine oxide (TMAO). Our previous work showed that TMAO contents increase with depth in muscles of several Pacific families of teleost fishes, to about 180 mmol/kg wet wt at 2.9 km depth in grenadiers. We now report that abyssal grenadiers (Coryphaenoides armatus, Macrouridae) from the Atlantic at 4.8 km depth contain 261 mmol/kg wet wt in muscle tissue. This precisely fits a linear trend extrapolated from the earlier data. We also found that anemones show a trend of increasing contents of methylamines (TMAO, betaine) and scyllo-inositol with increasing depth. Previously we found that TMAO counteracts the inhibitory effects of hydrostatic pressure on a variety of proteins. We now report that TMAO and, to a lesser extent, betaine, are generally better stabilizers than other common osmolytes (myo-inositol, taurine and glycine), in terms of counteracting the effects of pressure on NADH Km of grenadier lactate dehydrogenase and ADP Km of anemone and rabbit pyruvate kinase. PMID:15529747

  16. Effect of Excess Iodine on Oxidative Stress Markers, Steroidogenic-Enzyme Activities, Testicular Morphology, and Functions in Adult Male Rats.

    Science.gov (United States)

    Chakraborty, Arijit; Mandal, Jagadis; Mondal, Chiranjit; Sinha, Sabyasachi; Chandra, Amar K

    2016-08-01

    Improper iodine intake is a major concern in public health. Chronic intake of low iodine affects gonadal functions of man and animals; however, such effects of excess iodine in male reproduction, specially on testicular morphology, testicular steroidogenic enzyme activities, sperm morphology, sperm viability, and sperm count including male hormonal profiles in reference to iodine status and thyroid hormone profiles are yet to be explored. With this background, adult male rats of 120 ± 10 gm Bw of 90 ± 5 days were divided broadly in two groups depending on the duration of the treatment for 30 and 60 days, respectively. Both the groups consisted of control animals. Excess iodine (100EI), i.e., 100 times more than its recommended level but within its tolerable ranges, was administered through gavage regularly to the first group of experimental animals for 30 and 60 days, respectively, and excessive iodine (500EI), i.e., 500 times more than its recommended level and above tolerable range in the same way and for the same durations, was administered to the other group of experimental animals. Overall results revealed that regular consumption of iodine in excess impairs reproductive functions in adult male rats depending on the dose and duration of its exposure through different mechanisms. Excess iodine accumulates in the testis which results in generation of reactive oxygen species (ROS) as evidenced by higher lipid peroxidation level as well as an imbalance in the pro-/antioxidant status inhibiting the activity of ∆(5) 3β- hydroxysteroid dehydrogenase (HSD) and 17β-HSD resulting to reduced synthesis of testosterone that causes structural and functional changes of the testis. Secondly, persistent generation of ROS in testis as a result of prolonged excess iodine exposure affects hypothalamo-pituitary-adrenal axis that stimulates synthesis and secretion of corticosterone which inhibits LH release that downregulates testosterone synthesis causing further

  17. VX-509 (Decernotinib)-Mediated CYP3A Time-Dependent Inhibition: An Aldehyde Oxidase Metabolite as a Perpetrator of Drug-Drug Interactions.

    Science.gov (United States)

    Zetterberg, Craig; Maltais, Francois; Laitinen, Leena; Liao, Shengkai; Tsao, Hong; Chakilam, Ananthsrinivas; Hariparsad, Niresh

    2016-08-01

    (R)-2-((2-(1H-pyrrolo[2,3-b]pyridin-3-yl)pyrimidin-4-yl)amino)-2-methyl-N-(2,2,2-trifluoroethyl)butanamide (VX-509, decernotinib) is an oral Janus kinase 3 inhibitor that has been studied in patients with rheumatoid arthritis. Patients with rheumatoid arthritis often receive multiple medications, such as statins and steroids, to manage the signs and symptoms of comorbidities, which increases the chances of drug-drug interactions (DDIs). Mechanism-based inhibition is a subset of time-dependent inhibition (TDI) and occurs when a molecule forms a reactive metabolite which irreversibly binds and inactivates drug-metabolizing enzymes, potentially increasing the systemic load to toxic concentrations. Traditionally, perpetrating compounds are screened using human liver microsomes (HLMs); however, this system may be inadequate when the precipitant is activated by a non-cytochrome P450 (P450)-mediated pathway. Even though studies assessing competitive inhibition and TDI using HLM suggested a low risk for CYP3A4-mediated DDI in the clinic, VX-509 increased the area under the curve of midazolam, atorvastatin, and methyl-prednisolone by approximately 12.0-, 2.7-, and 4.3-fold, respectively. Metabolite identification studies using human liver cytosol indicated that VX-509 is converted to an oxidative metabolite, which is the perpetrator of the DDIs observed in the clinic. As opposed to HLM, hepatocytes contain the full complement of drug-metabolizing enzymes and transporters and can be used to assess TDI arising from non-P450-mediated metabolic pathways. In the current study, we highlight the role of aldehyde oxidase in the formation of the hydroxyl-metabolite of VX-509, which is involved in clinically significant TDI-based DDIs and represents an additional example in which a system-dependent prediction of TDI would be evident. PMID:27298338

  18. Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA.

    Science.gov (United States)

    Badalyan, Artavazd; Dierich, Marlen; Stiba, Konstanze; Schwuchow, Viola; Leimkühler, Silke; Wollenberger, Ulla

    2014-12-01

    Biosensors for the detection of benzaldehyde and γ-aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below -0.15 V (vs. Ag|AgCl, 1 M KCl). The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A "reagentless" biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10-150 µM and the detection limit of 5 µM (signal to noise ratio 3:1) of benzaldehyde. The relative standard deviation in a series (n = 13) for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T) and PaoABC in the osmium containing redox polymer.

  19. Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA

    Directory of Open Access Journals (Sweden)

    Artavazd Badalyan

    2014-11-01

    Full Text Available Biosensors for the detection of benzaldehyde and g-aminobutyric acid (GABA are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below −0.15 V (vs. Ag|AgCl, 1 M KCl. The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A “reagentless” biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10–150 µM and the detection limit of 5 µM (signal to noise ratio 3:1 of benzaldehyde. The relative standard deviation in a series (n = 13 for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T and PaoABC in the osmium containing redox polymer.

  20. Acetic acid assisted cobalt methanesulfonate catalysed chemoselective diacetylation of aldehydes

    Institute of Scientific and Technical Information of China (English)

    Min Wang; Zhi Guo Song; Hong Gong; Heng Jiang

    2008-01-01

    Cobalt methanesulfonate in combination with acetic acid catalysed the chemoselective diacetylation of aldehyde with acetic anhydride at room temperature under solvent free conditions. After reaction, cobalt methanesulfonate can be easily recovered and mused many times. The reaction was mild and efficient with good to high yields.

  1. Reaction of benzoxasilocines with aromatic aldehydes: Synthesis of homopterocarpans

    Directory of Open Access Journals (Sweden)

    Rodríguez-García Ignacio

    2007-02-01

    Full Text Available Abstract Condensation of 2H-benzo[g][1,2]oxasilocines with aromatic aldehydes in the presence of boron trifluoride affords mixtures of cis/trans 2-phenyl-3-vinylchromans with moderate yields. These can be transformed into homopterocarpans, a synthetic group of substances homologous to the natural isoflavonoid pterocarpans.

  2. Tandem Aldol Condensation – Platinacycle-Catalyzed Addition Reactions of Aldehydes, Methyl Ketones and Arylboronic Acids

    OpenAIRE

    Liao, Yuan-Xi; Hu, Qiao-Sheng

    2012-01-01

    Tandem aldol condensation of aldehydes with methyl ketones followed by anionic four-electron donor-based (Type I) platinacycle-catalyzed addition reactions of arylboronic acids to form β-arylated ketones is described. Good to excellent yields of β-arylated ketones were obtained for the tandem reactions of aromatic/aliphatic aldehydes, methyl ketones and arylboronic acids, and moderate yields were observed for the tandem reaction with α, β-unsaturated aldehydes as the aldehyde source.

  3. Identification and characterisation of Aedes aegypti aldehyde dehydrogenases involved in pyrethroid metabolism.

    Directory of Open Access Journals (Sweden)

    Nongkran Lumjuan

    Full Text Available Pyrethroid insecticides, especially permethrin and deltamethrin, have been used extensively worldwide for mosquito control. However, insecticide resistance can spread through a population very rapidly under strong selection pressure from insecticide use. The upregulation of aldehyde dehydrogenase (ALDH has been reported upon pyrethroid treatment. In Aedes aegypti, the increase in ALDH activity against the hydrolytic product of pyrethroid has been observed in DDT/permethrin-resistant strains. The objective of this study was to identify the role of individual ALDHs involved in pyrethroid metabolism.Three ALDHs were identified; two of these, ALDH9948 and ALDH14080, were upregulated in terms of both mRNA and protein levels in a DDT/pyrethroid-resistant strain of Ae. aegypti. Recombinant ALDH9948 and ALDH14080 exhibited oxidase activities to catalyse the oxidation of a permethrin intermediate, phenoxybenzyl aldehyde (PBald, to phenoxybenzoic acid (PBacid.ALDHs have been identified in association with permethrin resistance in Ae. aegypti. Characterisation of recombinant ALDHs confirmed the role of this protein in pyrethroid metabolism. Understanding the biochemical and molecular mechanisms of pyrethroid resistance provides information for improving vector control strategies.

  4. 外源NO处理对韭菜抗氧化酶活性的影响%Effects of Nitrogen Oxide Treatment on Antioxidant Enzymes in Chinese Chives

    Institute of Scientific and Technical Information of China (English)

    周春丽; 苏虎; 李玉萍; 范鸿冰; 吕玲琴; 钟贤武; 林彤

    2011-01-01

    [Objective] In order to study Chinese chives storage capacity, using external sources nitrogen oxide dealing with Chinese chives, the antioxidant enzyme activities were detected to speculate from Chinese chives freshness. [ Method] Different concentrations of exogenous NO donor sodium nitroprusside (SNP) solution were used to treat fresh-cut Chinese Chives, four kinds of antioxidant enzymes APX, CAT, POD and SOD activities were measured. [Result] The results showed that at a concentration of 0. 05 mmol/LSNP closed immersion 2 h, 7 days storage, fresh-cut Chinese Chives APX, CAT, POD activities were higher than those of control, SOD activity showed a downward trend. So the suitable concentration of NO could extend the storage life of fresh-cut Chinese Chives, slow the aging process, which had a good role in promoting the preservation of fresh-cut Chinese Chives. [ Conclusion] The right amount extraneous source NO can effectively enhance the antioxidant enzyme activities, extend shelf life preservation, and enhance effectiveness, providea theoretical basis for exploration of the fruit and vegetable preservation methods.%[目的]为了研究韭菜的耐贮能力,采用外源NO处理韭菜,通过韭菜体内抗氧化酶活性的检测,推断韭菜的新鲜度.[方法]用不同浓度外源NO供体硝普钠(SNP)溶液处理韭菜,分别测定4种抗氧化酶抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)的活性.[结果]用浓度0.05 mmol/L SNP密闭浸泡2h,贮藏7d左右,韭菜中APX、CAT、POD活性均比对照组高,SOD活性呈现缓慢下降的趋势.这说明适宜浓度外源NO处理能够延长韭菜的贮藏期,延缓衰老进程,对韭菜的保鲜有较好的促进作用.[结论]适量外源NO处理,能有效地提高贮藏过程中抗氧化酶活性,延长贮藏期,增强保鲜效果,可为果蔬保鲜方法的探索提供理论基础.

  5. Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction

    DEFF Research Database (Denmark)

    Taarning, Esben; Madsen, Robert

    2008-01-01

    A one-pot procedure is described for using alpha,beta-unsaturated aldehydes as olefin equivalents in the Diels-Alder reaction. The method combines the normal electron demand cycloaddition with aldehyde dienophiles and the rhodium-catalyzed decarbonylation of aldehydes to afford cyclohexenes with ...

  6. The enzymes associated with denitrification

    Science.gov (United States)

    Hochstein, L. I.; Tomlinson, G. A.

    1988-01-01

    The enzymes involved in the reduction of nitrogenous oxides are thought to be intermediates in denitrification processes. This review examines the roles of nitrate reductase, nitrite reductases, nitric oxide reductase, mechanisms of N-N bond formation, and nitrous oxide reductases.

  7. Effect of the allelic variants of aldehyde dehydrogenase ALDH2*2 and alcohol dehydrogenase ADH1B*2 on blood acetaldehyde concentrations

    OpenAIRE

    Peng Giia-Sheun; Yin Shih-Jiun

    2009-01-01

    Abstract Alcoholism is a complex behavioural disorder. Molecular genetics studies have identified numerous candidate genes associated with alcoholism. It is crucial to verify the disease susceptibility genes by correlating the pinpointed allelic variations to the causal phenotypes. Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the principal enzymes responsible for ethanol metabolism in humans. Both ADH and ALDH exhibit functional polymorphisms among racial populations; the...

  8. A new role for an old enzyme: Nitrate reductase-mediated nitric oxide generation is required for abscisic acid-induced stomatal closure in Arabidopsis thaliana

    Science.gov (United States)

    Desikan, Radhika; Griffiths, Rachael; Hancock, John; Neill, Steven

    2002-01-01

    The plant hormone abscisic acid (ABA), synthesized in response to water-deficit stress, induces stomatal closure via activation of complex signaling cascades. Recent work has established that nitric oxide (NO) is a key signaling molecule mediating ABA-induced stomatal closure. However, the biosynthetic origin of NO in guard cells has not yet been resolved. Here, we provide pharmacological, physiological, and genetic evidence that NO synthesis in Arabidopsis guard cells is mediated by the enzyme nitrate reductase (NR). Guard cells of wild-type Arabidopsis generate NO in response to treatment with ABA and nitrite, a substrate for NR. Moreover, NR-mediated NO synthesis is required for ABA-induced stomatal closure. However, in the NR double mutant, nia1, nia2 that has diminished NR activity, guard cells do not synthesize NO nor do the stomata close in response to ABA or nitrite, although stomatal opening is still inhibited by ABA. Furthermore, by using the ABA-insensitive (ABI) abi1–1 and abi2–1 mutants, we show that the ABI1 and ABI2 protein phosphatases are downstream of NO in the ABA signal-transduction cascade. These data demonstrate a previously uncharacterized signaling role for NR, that of mediating ABA-induced NO synthesis in Arabidopsis guard cells. PMID:12446847

  9. Preparation, crystallization and X-ray diffraction analysis to 1.5 Å resolution of rat cysteine dioxygenase, a mononuclear iron enzyme responsible for cysteine thiol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Chad R. [Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853-8001 (United States); Hao, Quan [MacCHESS at the Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853-8001 (United States); Stipanuk, Martha H., E-mail: mhs6@cornell.edu [Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853-8001 (United States)

    2005-11-01

    Recombinant rat cysteine dioxygenase (CDO) has been expressed, purified and crystallized and X-ray diffraction data have been collected to 1.5 Å resolution. Cysteine dioxygenase (CDO; EC 1.13.11.20) is an ∼23 kDa non-heme iron metalloenzyme that is responsible for the oxidation of cysteine by O{sub 2}, yielding cysteinesulfinate. CDO catalyzes the first step in the conversion of cysteine to taurine, as well as the first step in the catabolism of cysteine to pyruvate plus sulfate. Recombinant rat CDO was heterologously expressed, purified and crystallized. The protein was expressed as a fusion protein bearing a polyhistidine tag to facilitate purification, a thioredoxin tag to improve solubility and a factor Xa cleavage site to permit removal of the entire N-terminus, leaving only the 200 amino acids inherent to the native protein. A multi-step purification scheme was used to achieve >95% purity of CDO. The optimal CDO crystals diffracted to 1.5 Å resolution and belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 57.55, c = 123.06 Å, α = β = γ = 90°. CDO shows little homology to any other proteins; therefore, the structure of the enzyme will be determined by ab initio phasing using a selenomethionyl derivative.

  10. Preparation, Crystallization and X-ray Diffraction Analysis to 1.5 A Resolution of Rat Cysteine Dioxygenase, a Mononuclear Iron Enzyme Responsible for Cysteine Thiol Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Simmons,C.; Hao, Q.; Stipanuk, M.

    2005-01-01

    Cysteine dioxygenase (CDO; EC 1.13.11.20) is an {approx}23 kDa non-heme iron metalloenzyme that is responsible for the oxidation of cysteine by O2, yielding cysteinesulfinate. CDO catalyzes the first step in the conversion of cysteine to taurine, as well as the first step in the catabolism of cysteine to pyruvate plus sulfate. Recombinant rat CDO was heterologously expressed, purified and crystallized. The protein was expressed as a fusion protein bearing a polyhistidine tag to facilitate purification, a thioredoxin tag to improve solubility and a factor Xa cleavage site to permit removal of the entire N-terminus, leaving only the 200 amino acids inherent to the native protein. A multi-step purification scheme was used to achieve >95% purity of CDO. The optimal CDO crystals diffracted to 1.5 Angstroms resolution and belonged to space group P4{sub 3}2{sub 1}2 or P4{sub 1}2{sub 1}2, with unit-cell parameters a = b = 57.55, c = 123.06 Angstrom, {alpha} = {beta} = {gamma} = 90. CDO shows little homology to any other proteins; therefore, the structure of the enzyme will be determined by ab initio phasing using a selenomethionyl derivative.

  11. Possible Involvement of Anti-Oxidant Enzymes in the Cross-Tolerance of the Germination/Growth of Wheat Seeds to Salinity and Heat Stress

    Institute of Scientific and Technical Information of China (English)

    Yan-Bao LEI; Song-Quan SONG; Jia-Rui FU

    2005-01-01

    The germination/growth of wheat (Triticun aestivum L. cv. Zimai 1) seeds and changes in the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT), as well as in the content of thiobarbituric acid-reactive substances (TBARS), in response to salt and heat stress, as well as cross-stress, were investigated in the present study. With increasing temperature and decreasing water potential caused by NaC1 solution, the germination percentage of seeds and the fresh weight of seedlings decreased markedly, SOD activity increased, activities of APX and CAT decreased distinctly, and the TBARS content increased gradually. Seeds pretreated at 33 ℃ for different times displayed increased tolerance to subsequent salt stress, enhanced SOD, APX, and CAT activities, and decreased TBARS content. Seeds pretreated at -0.8 MPa NaC1 for different times displayed increased tolerance to subsequent heat stress and marked increases in SOD, APX, and CAT activities, which were associated with decreased TBARS content. It is considered that the common component in the cross-tolerance of the germination and growth of wheat seeds to salinity and heat stress is the anti-oxidant enzyme system.

  12. Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Gunnarsson, Thomas Gunnar Petursson; Thomassen, Martin;

    2015-01-01

    The present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic...... perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50...... between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P training with a volume reduction did not increase the content...

  13. An efficient and versatile synthesis of aromatic nitriles from aldehydes

    Institute of Scientific and Technical Information of China (English)

    Maryam Hajjami; Arash Ghorbani-Choghamarani; Mohammad Ali Zolfigol; Fatemeh Gholamian

    2012-01-01

    A simple and direct method has been developed for synthesis of nitriles based on one-pot reaction of aromatic aldehydes with three different kind of reagents:CeCl3·7H2O/KI/H2O2,CeCl3·7H2O/KI/UHP and (NH4)2Ce(NO3)6/KI/H2O2 in aqueous ammonia.

  14. Characterization of the rat Class 3 aldehyde dehydrogenase gene promoter.

    OpenAIRE

    Xie, Y Q; Takimoto, K; Pitot, H. C.; Miskimins, W K; Lindahl, R

    1996-01-01

    The Class 3 aldehyde dehydrogenase gene (ALDH-3) is differentially expressed. Expression is either constitutive or xenobiotic inducible via an aromatic hydrocarbon (Ah) receptor-mediated pathway, depending upon the tissue. A series of studies were performed to examine the regulation of rat ALDH-3 basal expression. DNase I footprint analysis identified four DNA regions within the proximal 1 kb of the 5' flanking region of rat ALDH-3 which interact with regulatory proteins. Reporter gene and ge...

  15. γ-Unsaturated aldehydes as potential Lilial replacers.

    Science.gov (United States)

    Schroeder, Martin; Mathys, Marion; Ehrensperger, Nadja; Büchel, Michelle

    2014-10-01

    A series of Claisen rearrangements was undertaken in order to find a replacement for Lilial (=3-(4-(tert-butyl)phenyl)-2-methylpropanal), a high-tonnage perfumery ingredient with a lily-of-the-valley odour, which is a CMR2 material [1]. 5,7,7-Trimethyl-4-methyleneoctanal (10), the synthesis of which is described, became the main lead. It possesses an odour which is very close to that of Lilial but lacks its substantivity. Aldehydes with higher molecular weights than that of 10 were, therefore, synthesised in order to boost substantivity and to understand the structural requirements for a 'Lilial' odour. The aldehydes were obtained via Claisen rearrangements of 'exo-methylidene' vinyl ethers, allenyl vinyl ethers, or allenyl allyl ethers. Alternatively, coupling of terminal alkynes with allyl alcohols led to the desired aldehydes. Derivatives of 10 and their sila analogues were also synthesised. The olfactory properties of all synthesised molecules were evaluated for possible structure-odour relationships (SOR). PMID:25329790

  16. Evaluation of milk enzymes and electrolytes, plasma metabolites, and oxidative status in twin cows milked in an automatic milking system or twice daily in a conventional milking parlor.

    Science.gov (United States)

    Abeni, F; Terzano, M G; Speroni, M; Migliorati, L; Capelletti, M; Calza, F; Bianchi, L; Pirlo, G

    2008-09-01

    The aim of this paper was to evaluate the effects of automatic milking (AM) on milk enzymes and minerals related to mammary epithelial integrity in comparison with twice-daily conventional milking (CM). One cow from each of 6 pairs of twins was assigned to be milked with AM or with CM throughout first lactation. Milk production was recorded and milk samples were collected at 4, 11, 18, 25, 32, and 39 wk of lactation (WOL) to determine fat and protein content, somatic cell count, pH, plasminogen (pl) and plasmin (Pl) activities, Na, K, and Cl. Body condition score was monitored; blood samples were collected to determine energy-related metabolites in the first third of lactation (14 WOL), and plasma oxidative status throughout lactation. Overall mean and standard deviation of milking frequency (MF) in AM were 2.69 and 0.88, respectively. Milk production, fat and protein contents, and somatic cell count did not differ between milking systems. The pl and pl+Pl activities were lesser in AM than in CM. Milk pH was greater in AM than in CM. Milk Na, K, Na/K ratio, and Cl did not differ across the whole lactation. Milk pH had a positive correlation with milk Pl activity (r = 0.41), Na (r = 0.37), and Cl (r = 0.40) concentration, and negative correlation with the log(10) of pl/Pl ratio (r = -0.47). The milk Na/K ratio had a positive correlation (r = 0.55) with milk Pl activity. Milking system (MS) did not seem to affect mammary epithelial permeability. The differences in enzymatic (proteolytic) activity due to the MS, probably related to daily MF, lead one to suppose that the quality of the protein fraction for the cheese-making process was preserved better with AM than with CM, even if differences in pH might negatively interfere. No difference was detected in BCS, and in plasma concentration of triglycerides and nonesterified fatty acids, whereas plasma cholesterol concentration during the first 10 WOL was lesser in AM than CM. Oxidative status, measured by plasma

  17. Characterization of aldehyde dehydrogenase isozymes in ovarian cancer tissues and sphere cultures

    International Nuclear Information System (INIS)

    Aldehyde dehydrogenases belong to a superfamily of detoxifying enzymes that protect cells from carcinogenic aldehydes. Of the superfamily, ALDH1A1 has gained most attention because current studies have shown that its expression is associated with human cancer stem cells. However, ALDH1A1 is only one of the 19 human ALDH subfamilies currently known. The purpose of the present study was to determine if the expression and activities of other major ALDH isozymes are associated with human ovarian cancer and ovarian cancer sphere cultures. Immunohistochemistry was used to delineate ALDH isozyme localization in clinical ovarian tissues. Western Blot analyses were performed on lysates prepared from cancer cell lines and ovarian cancer spheres to confirm the immunohistochemistry findings. Quantitative reverse transcription-polymerase chain reactions were used to measure the mRNA expression levels. The Aldefluor® assay was used to measure ALDH activity in cancer cells from the four tumor subtypes. Immunohistochemical staining showed significant overexpression of ALDH1A3, ALDH3A2, and ALDH7A1 isozymes in ovarian tumors relative to normal ovarian tissues. The expression and activity of ALDH1A1 is tumor type-dependent, as seen from immunohistochemisty, Western blot analysis, and the Aldefluor® assay. The expression was elevated in the mucinous and endometrioid ovarian epithelial tumors than in serous and clear cell tumors. In some serous and most clear cell tumors, ALDH1A1 expression was found in the stromal fibroblasts. RNA expression of all studied ALDH isozymes also showed higher expression in endometrioid and mucinous tumors than in the serous and clear cell subtypes. The expression of ALDH enzymes showed tumor type-dependent induction in ovarian cancer cells growing as sphere suspensions in serum-free medium. The results of our study indicate that ALDH enzyme expression and activity may be associated with specific cell types in ovarian tumor tissues and vary according to

  18. Protocatechuic aldehyde inhibits migration and proliferation of vascular smooth muscle cells and intravascular thrombosis

    International Nuclear Information System (INIS)

    Highlights: ► Protocatechuic aldehyde (PCA) inhibits ROS production in VSMCs. ► PCA inhibits proliferation and migration in PDGF-induced VSMCs. ► PCA has anti-platelet effects in ex vivo rat whole blood. ► We report the potential therapeutic role of PCA in atherosclerosis. -- Abstract: The migration and proliferation of vascular smooth muscle cells (VSMCs) and formation of intravascular thrombosis play crucial roles in the development of atherosclerotic lesions. This study examined the effects of protocatechuic aldehyde (PCA), a compound isolated from the aqueous extract of the root of Salvia miltiorrhiza, an herb used in traditional Chinese medicine to treat a variety of vascular diseases, on the migration and proliferation of VSMCs and platelets due to platelet-derived growth factor (PDGF). DNA 5-bromo-2′-deoxy-uridine (BrdU) incorporation and wound-healing assays indicated that PCA significantly attenuated PDGF-induced proliferation and migration of VSMCs at a pharmacologically relevant concentration (100 μM). On a molecular level, we observed down-regulation of the phosphatidylinositol 3-kinase (PI3K)/Akt and the mitogen-activated protein kinase (MAPK) pathways, both of which regulate key enzymes associated with migration and proliferation. We also found that PCA induced S-phase arrest of the VSMC cell cycle and suppressed cyclin D2 expression. In addition, PCA inhibited PDGF-BB-stimulated reactive oxygen species production in VSMCs, indicating that PCA’s antioxidant properties may contribute to its suppression of PDGF-induced migration and proliferation in VSMCs. Finally, PCA exhibited an anti-thrombotic effect related to its inhibition of platelet aggregation, confirmed with an aggregometer. Together, these findings suggest a potential therapeutic role of PCA in the treatment of atherosclerosis and angioplasty-induced vascular restenosis.

  19. Protocatechuic aldehyde inhibits migration and proliferation of vascular smooth muscle cells and intravascular thrombosis

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Chang Yoon [The Hotchkiss School, Lakeville, CT (United States); Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Ku, Cheol Ryong [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cho, Yoon Hee, E-mail: wooriminji@gmail.com [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Lee, Eun Jig, E-mail: ejlee423@yuhs.ac [Endocrinology, Brain Korea 21 Project for Medical Science, Institute of Endocrine Research, and Severance Integrative Research Institute for Cerebral and Cardiovascular Disease, Yonsei University College of Medicine, Seoul (Korea, Republic of); Endocrinology, Northwestern University Feinberg School of Medicine, Chicago, IL (United States)

    2012-06-22

    Highlights: Black-Right-Pointing-Pointer Protocatechuic aldehyde (PCA) inhibits ROS production in VSMCs. Black-Right-Pointing-Pointer PCA inhibits proliferation and migration in PDGF-induced VSMCs. Black-Right-Pointing-Pointer PCA has anti-platelet effects in ex vivo rat whole blood. Black-Right-Pointing-Pointer We report the potential therapeutic role of PCA in atherosclerosis. -- Abstract: The migration and proliferation of vascular smooth muscle cells (VSMCs) and formation of intravascular thrombosis play crucial roles in the development of atherosclerotic lesions. This study examined the effects of protocatechuic aldehyde (PCA), a compound isolated from the aqueous extract of the root of Salvia miltiorrhiza, an herb used in traditional Chinese medicine to treat a variety of vascular diseases, on the migration and proliferation of VSMCs and platelets due to platelet-derived growth factor (PDGF). DNA 5-bromo-2 Prime -deoxy-uridine (BrdU) incorporation and wound-healing assays indicated that PCA significantly attenuated PDGF-induced proliferation and migration of VSMCs at a pharmacologically relevant concentration (100 {mu}M). On a molecular level, we observed down-regulation of the phosphatidylinositol 3-kinase (PI3K)/Akt and the mitogen-activated protein kinase (MAPK) pathways, both of which regulate key enzymes associated with migration and proliferation. We also found that PCA induced S-phase arrest of the VSMC cell cycle and suppressed cyclin D2 expression. In addition, PCA inhibited PDGF-BB-stimulated reactive oxygen species production in VSMCs, indicating that PCA's antioxidant properties may contribute to its suppression of PDGF-induced migration and proliferation in VSMCs. Finally, PCA exhibited an anti-thrombotic effect related to its inhibition of platelet aggregation, confirmed with an aggregometer. Together, these findings suggest a potential therapeutic role of PCA in the treatment of atherosclerosis and angioplasty-induced vascular restenosis.

  20. Protective effects of a wheat germ rich diet against the toxic influence of profenofos on rat tissue lipids and oxidative pentose phosphate shunt enzymes

    Directory of Open Access Journals (Sweden)

    Abdel-Rahim, G. A.

    2011-09-01

    Full Text Available The effects of technical and formulated forms of profenofos on the metabolic lipid fractions of the liver, brain and kidneys as well as the activity of glucose-6-phosphate dehydrogenase (G6PD and 6-phosphogluconate dehydrogenase (6PGD, which consider lipid related enzymes, were studied. The two forms of profenofos were given separately either orally or by dermal at doses of 1/20 LD50 for 3 months (one dose every 48 h. Total lipids and lipid fractions (cholesterol, triglycerides and phospholipid contents decreased in the three studied organ tissues either in technical or formulated profenofos-induced rats compared with normal control animals. The highest effect was observed in the case of orally formulated profenofo induction, and the lowest was detected for the dermal technical one. The same trend was found in the activities of G6PD and 6PGD associated with lipid metabolism in the liver, brain and kidney tissues under the same conditions. On other hand, the treatment of profenofos-induced animals by feeding a wheat germ rich diet (as antioxidant agent produced significant improvements in both lipid fraction content and enzyme activity. In addition, the effects of the wheat germ rich diet (α-tocopherol rich source readjusted and improved the disturbed metabolic fractions of the lipid profiles in the profenofos-induced rats as well as their related enzyme activities (G6PD and 6PGD: oxidative pentose phosphate shunt.

    El efecto de formas técnicas o formuladas de profenofós en la fracción lipídica metabólica de hígado, cerebro y riñones así como la actividad de la glucosa-6-fosfato deshidrogenasa (G6PD y 6-fosfogluconato deshidrogenasa (6PGD, que son consideradas enzimas relacionadas con los lípidos, fueron estudiadas. Ambas formas de profenofós fueron suministradas separadamente tanto por vía oral como cutánea a una dosis de 1/20 LD50 durante 3 meses (una dosis cada 48 horas. Los lípidos totales y

  1. [GENES ALLELE STATUS OF ANGIOTENSINCONVERTING ENZYME (I/D) AND ENDOTHELIAL NITRIC OXIDE SYNTHASE (894 G > T) IN PATIENTS WITH ACUTE CORONARY SYNDROME].

    Science.gov (United States)

    Sydorchuk, L P; Ursuliak, Y V

    2015-01-01

    The association of genes polymorphism of angiotensin-converting enzyme ACE (I/D) and endothelial nitric oxide synthase eNOS (894 G > T) with acute myocardial infarction (MI) among residents of North Bukovina region was evaluated. II/GG and ID/GG haplotypesre associated with more frequent presence of Q-MI, with localization on anterior wall and primary appearance. ID/TT, or II/TG haplotypes are associated with the presence of a severe re-Q-MI, with localization on the posterior wall. ID/TG variant is associated in 93.7% of cases with Q-MI, regardless of its location and times of occurrence. ID/TG increased relative risk of Q-MI by 2,93 times (OR = 4,79; P = 0,002), which confirmed the severity of the disease and increases the risk of MI inanterior and higher in posterior walls of the left ventricle (OR = 4.31; P = 0.007 and OR = 4.6; P = 0.005, respectively) increases the likelihood of the first Ml by 2.88 times (OR = 4.62; P = 0.003) and its re-occurrence or recurrence--by 2.67 times (OR = 4; P = 0.022). Mutations absence: in haplotypes (II/GG) is a protective factor of Q-MI appearance (OR = 0.19; P = 0.004) and makes the chances for the first MI the lowest in observed population (OR = 0.36; P = 0.045). PMID:27089712

  2. CorA affects tolerance of Escherichia coli and Salmonella enterica serovar Typhimurium to the lactoperoxidase enzyme system but not to other forms of oxidative stress.

    Science.gov (United States)

    Sermon, Jan; Wevers, Eva M-R P; Jansen, Leentje; De Spiegeleer, Philipp; Vanoirbeek, Kristof; Aertsen, Abram; Michiels, Chris W

    2005-11-01

    The enzyme lactoperoxidase is part of the innate immune system in vertebrates and owes its antimicrobial activity to the formation of oxidative reaction products from various substrates. In a previous study, we have reported that, with thiocyanate as a substrate, the lactoperoxidase system elicits a distinct stress response in Escherichia coli MG1655. This response is different from but partly overlapping with the stress responses to hydrogen peroxide and to superoxide. In the current work, we constructed knockouts in 10 lactoperoxidase system-inducible genes to investigate their role in the tolerance of E. coli MG1655 to this antimicrobial system. Five mutations resulted in a slightly increased sensitivity, but one mutation (corA) caused hypersensitivity to the lactoperoxidase system. This hypersensitive phenotype was specific to the lactoperoxidase system, since neither the sensitivity to hydrogen peroxide nor to the superoxide generator plumbagin was affected in the corA mutant. Salmonella enterica serovar Typhimurium corA had a similar phenotype. Although corA encodes an Mg2+ transporter and at least three other inducible open reading frames belonged to the Mg2+ regulon, repression of the Mg stimulon by Mg2+ did not change the lactoperoxidase sensitivity of either the wild-type or corA mutant. Prior exposure to 0.3 mM Ni2+, which is also transported by CorA, strongly sensitized MG1655 but not the corA mutant to the lactoperoxidase system. Furthermore, this Ni2+-dependent sensitization was suppressed by the CorA-specific inhibitor Co(III) hexaammine. These results indicate that CorA affects the lactoperoxidase sensitivity of E. coli by modulating the cytoplasmic concentrations of transition metals that enhance the toxicity of the lactoperoxidase system.

  3. Alpha lipoic acid protects lens from H2O2-induced cataract by inhibiting apoptosis of lens epithelial cells and inducing activation of anti-oxidative enzymes

    Institute of Scientific and Technical Information of China (English)

    Yun Li; Ya-Zhen Liu; Jing-Ming Shi; Song-Bai Jia

    2013-01-01

    Objective: To determine whether alpha lipoic acid (LA) can effectively protect lenses from hydrogen peroxide (H2O2)-induced cataract. Methods: Lens from adult Sprague-Dawley rats were cultured in 24-well plates and treated without or with 0.2 mM of H2O2, 0.2 mM of H2O2 plus 0.5 mM, 1.0 mM, or 2.0 mM of LA for 24 h. Cataract was assessed using cross line grey scale measurement. Superoxide dismutase (SOD), glutathione (GSH-Px), lactate dehydrogenase (LDH), and malondialdehyde (MDA) activity or level in lens homogenates was measured. Apoptosis of lens epithelial cells in each group were detected by Terminal Deoxynucleotidyl Transferase dUTP Nick End Labeling (TUNEL) Assay. Results: A total of 0.2 mM of H2O2 induced obvious cataract formation and apoptosis in lens’ epithelial cells, but 0.5-2.0 mM of LA could block the effect of 0.2 mM H2O2 in inducing cataract and apoptosis. Furthermore, 0.2 mM of H2O2 significantly decreased SOD, GSH-Px, and LDH activity and significant increased MDA level in the lens, but 0.5-2.0 mM of LA blocked the effect of 0.2 mM H2O2. One mM of LA was found to be the most effective. Conclusions: LA can protect lens from H2O2-induced cataract. LA exerts protective effects through inhibition of lens’ epithelial cell apoptosis and activation of anti-oxidative enzymes.

  4. Stopped-flow kinetic studies of electron transfer in the reductase domain of neuronal nitric oxide synthase: re-evaluation of the kinetic mechanism reveals new enzyme intermediates and variation with cytochrome P450 reductase.

    Science.gov (United States)

    Knight, Kirsty; Scrutton, Nigel S

    2002-01-01

    The reduction by NADPH of the FAD and FMN redox centres in the isolated flavin reductase domain of calmodulin-bound rat neuronal nitric oxide synthase (nNOS) has been studied by anaerobic stopped-flow spectroscopy using absorption and fluorescence detection. We show by global analysis of time-dependent photodiode array spectra, single wavelength absorption and NADPH fluorescence studies, that at least four resolvable steps are observed in stopped-flow studies with NADPH and that flavin reduction is reversible. The first reductive step represents the rapid formation of an equilibrium between an NADPH-enzyme charge-transfer species and two-electron-reduced enzyme bound to NADP(+). The second and third steps represent further reduction of the enzyme flavins and NADP(+) release. The fourth step is attributed to the slow accumulation of an enzyme species that is inferred not to be relevant catalytically in steady-state reactions. Stopped-flow flavin fluorescence studies indicate the presence of slow kinetic phases, the timescales of which correspond to the slow phase observed in absorption and NADPH fluorescence transients. By analogy with stopped-flow studies of cytochrome P450 reductase, we attribute these slow fluorescence and absorption changes to enzyme disproportionation and/or conformational change. Unlike for the functionally related cytochrome P450 reductase, transfer of the first hydride equivalent from NADPH to nNOS reductase does not generate the flavin di-semiquinoid state. This indicates that internal electron transfer is relatively slow and is probably gated by NADP(+) release. Release of calmodulin from the nNOS reductase does not affect the kinetics of inter-flavin electron transfer under stopped-flow conditions, although the observed rate of formation of the equilibrium between the NADPH-oxidized enzyme charge-transfer species and two-electron-reduced enzyme bound to NADP(+) is modestly slower in calmodulin-depleted enzyme. Our studies indicate the

  5. In vitro assessment of human airway toxicity from major aldehydes in automotive emissions

    Energy Technology Data Exchange (ETDEWEB)

    Grafstroem, R.C. [Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine

    1997-09-01

    Automotive exhausts can significantly contribute to the levels of reactive aldehydes, including formaldehyde, acetaldehyde and acrolein, in urban air. The use of alcohols as an alternative fuel for gasoline or diesel may further increase these emissions. Since it is unclear if aldehyde inhalation may induce pathological states, including cancer, in human airways, the toxic properties of the above-mentioned aldehydes were studied in cultured target cell types. Each aldehyde modified vital cellular functions in a dose-dependent manner, and invariably inhibited growth and induced abnormal terminal differentiation. Decreases of cellular thiols and increases of intracellular Ca{sup 2+} were observed, and moreover, variable types and amounts of short-lived or persistent genetic damage were induced. The concentrations required for specified levels of a particular type of injury varied up to 10000-fold among the aldehydes. Overall, distinctive patterns of cytopathological activity were observed, which differed both qualitatively and quantitatively among the aldehydes. Finally, aldehydes inhibited DNA repair processes and increased cytotoxicity and mutagenesis in synergy with other known toxicants, indicating that aldehydes may also enhance damage by other constituents in automotive exhausts. In summary, the aldehydes, notably {sup m}u{sup M}-mM formaldehyde, caused pathological effects and induced mechanisms that relate to acute toxicity and cancer development in airway epithelial cells. Since `no-effect` levels may not exist for carcinogenic agents, the overall results support a need for elimination of aldehydes in automotive exhausts. 41 refs

  6. Selective oxidation of benzylic alcohols using copper-manganese mixed oxide nanoparticles as catalyst

    Directory of Open Access Journals (Sweden)

    Roushown Ali

    2015-07-01

    Full Text Available The catalytic activity of copper-manganese (CuMn2 mixed oxide nanoparticles (Cu/Mn = 1:2 has been studied for the selective oxidation of benzylic alcohols to the corresponding aldehydes using molecular oxygen as an oxidizing agent. The CuMn2 mixed oxide showed excellent catalytic activity for the oxidation of benzylic alcohols to the corresponding aldehydes with high selectivity (>99%. The complete conversion (100% of all the benzylic alcohols to the corresponding aldehydes is achieved within a short reaction period at 102 °C. The catalytic performance is obtained to be dependent on the electronic and steric effects of the substituents present on the phenyl ring. Electron withdrawing and bulky groups attached to the phenyl ring required longer reaction time for a complete conversion of the benzylic alcohols.

  7. Development of a microfluidic paper-based analytical device for the determination of salivary aldehydes.

    Science.gov (United States)

    Ramdzan, Adlin N; Almeida, M Inês G S; McCullough, Michael J; Kolev, Spas D

    2016-05-01

    A low cost, disposable and easy to use microfluidic paper-based analytical device (μPAD) was developed for simple and non-invasive determination of total aldehydes in saliva with a potential to be used in epidemiological studies to assess oral cancer risk. The μPAD is based on the colour reaction between aldehydes (e.g. acetaldehyde, formaldehyde), 3-methyl-2-benzothiazolinone hydrazone (MBTH) and iron(III) to form an intense blue coloured formazan dye. The newly developed μPAD has a 3D design with two overlapping paper layers. The first layer comprises 15 circular detection zones (8 mm in diameter), each impregnated with 8 μL of MBTH, while the second layer contains 15 reagent zones (4 mm in diameter). Two μL of iron(III) chloride are added to each one of the second layer zones after the addition of sample to the detection zones in the first layer. All hydrophilic zones of the μPAD are defined by wax printing using a commercial wax printer. Due to the 2-step nature of the analytical reaction, the two paper layers are separated by a cellulose acetate interleaving sheet to allow for the reaction between the aldehydes in the saliva sample with MBTH to proceed first with the formation of an azine, followed by a blue coloured reaction between the azine and the oxidized by iron(III) form of MBTH, produced after the removal of the interleaving sheet. After obtaining a high resolution image of the detection side zone of the device using a flatbed scanner, the intensity of the blue colour within each detection zone is measured with Image J software. Under optimal conditions, the μPAD is characterised by a working range of 20.4-114.0 μM, limit of detection of 6.1 μM, and repeatability, expressed as RSD, of less than 12.7% (n = 5). There is no statistically significant difference at the 95% confidence level between the results obtained by the μPAD and the reference method (Student's t-test: 0.090 < 0.38). The optimized μPAD is stable for more than 41 days

  8. Loss of collectrin, an angiotensin-converting enzyme 2 homolog, uncouples endothelial nitric oxide synthase and causes hypertension and vascular dysfunction

    DEFF Research Database (Denmark)

    Cechova, Sylvia; Zeng, Qing; Billaud, Marie;

    2013-01-01

    Collectrin is an orphan member of the renin-angiotensin system and is a homolog of angiotensin-converting enzyme 2, sharing ≈50% sequence identity. Unlike angiotensin-converting enzyme 2, collectrin lacks any catalytic domain. Collectrin has been shown to function as a chaperone of amino acid tra...

  9. Gold-catalyzed oxidation of arylallenes: Synthesis of quinoxalines and benzimidazoles

    OpenAIRE

    Ying Chen; Dan-Wen Zhuang; Dong-Mei Cui; Chen Zhang

    2011-01-01

    A gold-catalyzed oxidation of arylallenes to form α-diketones and aldehydes in good yields is presented. Further directed synthesis of quinoxalines and benzimidazoles, via the condensation of the resulting α-diketones and aldehydes with benzene-1,2-diamine, was achieved in high yields.

  10. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    OpenAIRE

    Phillips, T. K.; Clarke, Stuart M.; Castro Arroyo, Miguel Ángel; Millán, Carmen; Medina, Santiago

    2011-01-01

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C 7, C 9 and C 11) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C 11 homologue...

  11. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    International Nuclear Information System (INIS)

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C7, C9 and C11) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C11 homologue is determined to have a plane group of either p2, pgb or pgg, and for the C7 homologue the p2 plane group is preferred.

  12. Hydrogenations without Hydrogen: Titania Photocatalyzed Reductions of Maleimides and Aldehydes

    Directory of Open Access Journals (Sweden)

    David W. Manley

    2014-09-01

    Full Text Available A mild procedure for the reduction of electron-deficient alkenes and carbonyl compounds is described. UVA irradiations of substituted maleimides with dispersions of titania (Aeroxide P25 in methanol/acetonitrile (1:9 solvent under dry anoxic conditions led to hydrogenation and production of the corresponding succinimides. Aromatic and heteroaromatic aldehydes were reduced to primary alcohols in similar titania photocatalyzed reactions. A mechanism is proposed which involves two proton-coupled electron transfers to the substrates at the titania surface.

  13. Nuclear alkylated pyridine aldehyde polymers and conductive compositions thereof

    Science.gov (United States)

    Rembaum, A.; Singer, S. (Inventor)

    1970-01-01

    A thermally stable, relatively conductive polymer was disclosed. The polymer was synthesized by condensing in the presence of catalyst a 2, 4, or 6 nuclear alklylated 2, 3, or 4 pyridine aldehyde or quaternary derivatives thereof to form a polymer. The pyridine groups were liked by olefinic groups between 2-4, 2-6, 2-3, 3-4, 3-6 or 4-6 positions. Conductive compositions were prepared by dissolving the quaternary polymer and an organic charge transfer complexing agent such as TCNQ in a mutual solvent such as methanol.

  14. Inhibitory Potencies of Several Iridoids on Cyclooxygenase-1, Cyclooxygnase-2 Enzymes Activities, Tumor Necrosis Factor-α and Nitric Oxide Production In Vitro

    Directory of Open Access Journals (Sweden)

    Kyoung Sik Park

    2010-01-01

    Full Text Available To verify the anti-inflammatory potency of iridoids, seven iridoid glucosides (aucubin, catalpol, gentiopicroside, swertiamarin, geniposide, geniposidic acid and loganin and an iridoid aglycone (genipin were investigated with in vitro testing model systems based on inhibition of cyclooxygenase (COX-1/-2 enzymes, the tumor necrosis factor-α (TNF-α formation and nitric oxide (NO production. The hydrolyzed-iridoid products (H-iridoid with β-gludosidase treatment only showed inhibitory activities, and revealed different potencies, depending on their chemical structures. Without the β-gludosidase treatment, no single iridoid glycoside exhibited any activities. The aglycone form (genipin also did not show inhibitory activities. To compare anti-inflammatory potency, the inhibitory concentrations (IC50 in each testing system were measured. The hydrolyzed-aucubin product (H-aucubin with β-gludosidase treatment showed a moderate inhibition on COX-2 with IC50 of 8.83 μM, but much less inhibition (IC50, 68.9 μM on COX-1 was noted. Of the other H-iridoid products, the H-loganin and the H-geniposide exhibited higher inhibitory effects on COX-1, revealing IC50 values of 3.55 and 5.37 μM, respectively. In the case of TNF-α assay, four H-iridoid products: H-aucubin, H-catalpol, H-geniposide and H-loganin suppressed the TNF-α formation with IC50 values of 11.2, 33.3, 58.2 and 154.6 μM, respectively. But other H-iridoid products manifested no significant activity. Additional experiments on NO production were conducted. We observed that only the H-aucubin exhibited a significant suppression with IC50 value of 14.1 μM. Genipin, an agycone form, showed no inhibitory effects on all testing models, implying the hydrolysis of the glycosidic bond of iridoid glycoside is a pre-requisite step to produce various biological activities.

  15. Microwave Assisted Solvent Free Synthesis of Azomethines from Aryl Aldehydes on Melamin Formaldehyde as Solid Support

    OpenAIRE

    Ramin Rezaei; Mohammadi, Mohammad K; Tahereh Ranjbar

    2011-01-01

    Various aryl aldehydes underwent prompt one pot conversion into the corresponding azomethines in high yields by reacting with hydroxylamine hydrochloride supported on melamine formaldehyde under microwave irradiation.

  16. A Catalase-related Hemoprotein in Coral Is Specialized for Synthesis of Short-chain Aldehydes: DISCOVERY OF P450-TYPE HYDROPEROXIDE LYASE ACTIVITY IN A CATALASE.

    Science.gov (United States)

    Teder, Tarvi; Lõhelaid, Helike; Boeglin, William E; Calcutt, Wade M; Brash, Alan R; Samel, Nigulas

    2015-08-01

    In corals a catalase-lipoxygenase fusion protein transforms arachidonic acid to the allene oxide 8R,9-epoxy-5,9,11,14-eicosatetraenoic acid from which arise cyclopentenones such as the prostanoid-related clavulones. Recently we cloned two catalase-lipoxygenase fusion protein genes (a and b) from the coral Capnella imbricata, form a being an allene oxide synthase and form b giving uncharacterized polar products (Lõhelaid, H., Teder, T., Tõldsepp, K., Ekins, M., and Samel, N. (2014) PloS ONE 9, e89215). Here, using HPLC-UV, LC-MS, and NMR methods, we identify a novel activity of fusion protein b, establishing its role in cleaving the lipoxygenase product 8R-hydroperoxy-eicosatetraenoic acid into the short-chain aldehydes (5Z)-8-oxo-octenoic acid and (3Z,6Z)-dodecadienal; these primary products readily isomerize in an aqueous medium to the corresponding 6E- and 2E,6Z derivatives. This type of enzymatic cleavage, splitting the carbon chain within the conjugated diene of the hydroperoxide substrate, is known only in plant cytochrome P450 hydroperoxide lyases. In mechanistic studies using (18)O-labeled substrate and incubations in H2(18)O, we established synthesis of the C8-oxo acid and C12 aldehyde with the retention of the hydroperoxy oxygens, consistent with synthesis of a short-lived hemiacetal intermediate that breaks down spontaneously into the two aldehydes. Taken together with our initial studies indicating differing gene regulation of the allene oxide synthase and the newly identified catalase-related hydroperoxide lyase and given the role of aldehydes in plant defense, this work uncovers a potential pathway in coral stress signaling and a novel enzymatic activity in the animal kingdom.

  17. Dietary supplementation of green synthesized manganese-oxide nanoparticles and its effect on growth performance, muscle composition and digestive enzyme activities of the giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Asaikkutti, Annamalai; Bhavan, Periyakali Saravana; Vimala, Karuppaiya; Karthik, Madhayan; Cheruparambath, Praseeja

    2016-05-01

    The green synthesized Mn3O4 nanoparticles (manganese-oxide nanoparticles) using Ananas comosus (L.) peel extract was characterized by various techniques. HR-SEM photograph showed that manganese-oxide nanoparticles (Mn-oxide NPs) were spherical in shape, with an average size of 40-50 nm. The Zeta potential revealed the surface charge of Mn-oxide NPs to be negative. Further, the Mn-oxide NPs were dietary supplemented for freshwater prawn Macrobrachium rosenbergii. The experimental basal diets were supplemented with Mn-oxide NPs at the rates of 0 (control), 3.0, 6.0, 9.0, 12, 15 and 18 mg/kg dry feed weight. The as-supplemented Mn-oxide NPs were fed in M. rosenbergii for a period of 90 days. The experimental study demonstrated that prawns fed with diet supplemented with 3-18 mg Mn-oxide NPs/kg shows enhanced (P0.05) alterations in prawns fed with 3.0-18 mg/kg of Mn-oxide NPs supplemented diets. Consequently, the present work proposed that 16 mg/kg of Mn-oxide NPs could be supplemented for flexible enhanced survival, growth and production of M. rosenbergii. Therefore, the data of the present study recommend the addition of 16 mg/kg of Mn-oxide NPs diet to developed prawn growth and antioxidant defense system.

  18. CYP76C1 (Cytochrome P450)-Mediated Linalool Metabolism and the Formation of Volatile and Soluble Linalool Oxides in Arabidopsis Flowers: A Strategy for Defense against Floral Antagonists.

    Science.gov (United States)

    Boachon, Benoît; Junker, Robert R; Miesch, Laurence; Bassard, Jean-Etienne; Höfer, René; Caillieaudeaux, Robin; Seidel, Dana E; Lesot, Agnès; Heinrich, Clément; Ginglinger, Jean-François; Allouche, Lionel; Vincent, Bruno; Wahyuni, Dinar S C; Paetz, Christian; Beran, Franziska; Miesch, Michel; Schneider, Bernd; Leiss, Kirsten; Werck-Reichhart, Danièle

    2015-10-01

    The acyclic monoterpene alcohol linalool is one of the most frequently encountered volatile compounds in floral scents. Various linalool oxides are usually emitted along with linalool, some of which are cyclic, such as the furanoid lilac compounds. Recent work has revealed the coexistence of two flower-expressed linalool synthases that produce the (S)- or (R)-linalool enantiomers and the involvement of two P450 enzymes in the linalool oxidation in the flowers of Arabidopsis thaliana. Partially redundant enzymes may also contribute to floral linalool metabolism. Here, we provide evidence that CYP76C1 is a multifunctional enzyme that catalyzes a cascade of oxidation reactions and is the major linalool metabolizing oxygenase in Arabidopsis flowers. Based on the activity of the recombinant enzyme and mutant analyses, we demonstrate its prominent role in the formation of most of the linalool oxides identified in vivo, both as volatiles and soluble conjugated compounds, including 8-hydroxy, 8-oxo, and 8-COOH-linalool, as well as lilac aldehydes and alcohols. Analysis of insect behavior on CYP76C1 mutants and in response to linalool and its oxygenated derivatives demonstrates that CYP76C1-dependent modulation of linalool emission and production of linalool oxides contribute to reduced floral attraction and favor protection against visitors and pests.

  19. CYP76C1 (Cytochrome P450)-Mediated Linalool Metabolism and the Formation of Volatile and Soluble Linalool Oxides in Arabidopsis Flowers: A Strategy for Defense against Floral Antagonists[OPEN

    Science.gov (United States)

    Lesot, Agnès; Ginglinger, Jean-François; Beran, Franziska; Schneider, Bernd; Leiss, Kirsten; Werck-Reichhart, Danièle

    2015-01-01

    The acyclic monoterpene alcohol linalool is one of the most frequently encountered volatile compounds in floral scents. Various linalool oxides are usually emitted along with linalool, some of which are cyclic, such as the furanoid lilac compounds. Recent work has revealed the coexistence of two flower-expressed linalool synthases that produce the (S)- or (R)-linalool enantiomers and the involvement of two P450 enzymes in the linalool oxidation in the flowers of Arabidopsis thaliana. Partially redundant enzymes may also contribute to floral linalool metabolism. Here, we provide evidence that CYP76C1 is a multifunctional enzyme that catalyzes a cascade of oxidation reactions and is the major linalool metabolizing oxygenase in Arabidopsis flowers. Based on the activity of the recombinant enzyme and mutant analyses, we demonstrate its prominent role in the formation of most of the linalool oxides identified in vivo, both as volatiles and soluble conjugated compounds, including 8-hydroxy, 8-oxo, and 8-COOH-linalool, as well as lilac aldehydes and alcohols. Analysis of insect behavior on CYP76C1 mutants and in response to linalool and its oxygenated derivatives demonstrates that CYP76C1-dependent modulation of linalool emission and production of linalool oxides contribute to reduced floral attraction and favor protection against visitors and pests. PMID:26475865

  20. CYP76C1 (Cytochrome P450)-Mediated Linalool Metabolism and the Formation of Volatile and Soluble Linalool Oxides in Arabidopsis Flowers: A Strategy for Defense against Floral Antagonists.

    Science.gov (United States)

    Boachon, Benoît; Junker, Robert R; Miesch, Laurence; Bassard, Jean-Etienne; Höfer, René; Caillieaudeaux, Robin; Seidel, Dana E; Lesot, Agnès; Heinrich, Clément; Ginglinger, Jean-François; Allouche, Lionel; Vincent, Bruno; Wahyuni, Dinar S C; Paetz, Christian; Beran, Franziska; Miesch, Michel; Schneider, Bernd; Leiss, Kirsten; Werck-Reichhart, Danièle

    2015-10-01

    The acyclic monoterpene alcohol linalool is one of the most frequently encountered volatile compounds in floral scents. Various linalool oxides are usually emitted along with linalool, some of which are cyclic, such as the furanoid lilac compounds. Recent work has revealed the coexistence of two flower-expressed linalool synthases that produce the (S)- or (R)-linalool enantiomers and the involvement of two P450 enzymes in the linalool oxidation in the flowers of Arabidopsis thaliana. Partially redundant enzymes may also contribute to floral linalool metabolism. Here, we provide evidence that CYP76C1 is a multifunctional enzyme that catalyzes a cascade of oxidation reactions and is the major linalool metabolizing oxygenase in Arabidopsis flowers. Based on the activity of the recombinant enzyme and mutant analyses, we demonstrate its prominent role in the formation of most of the linalool oxides identified in vivo, both as volatiles and soluble conjugated compounds, including 8-hydroxy, 8-oxo, and 8-COOH-linalool, as well as lilac aldehydes and alcohols. Analysis of insect behavior on CYP76C1 mutants and in response to linalool and its oxygenated derivatives demonstrates that CYP76C1-dependent modulation of linalool emission and production of linalool oxides contribute to reduced floral attraction and favor protection against visitors and pests. PMID:26475865

  1. The effect of peroxynitrite decomposition catalyst MnTBAP on aldehyde dehydrogenase-2 nitration by organic nitrates: role in nitrate tolerance.

    Science.gov (United States)

    Mollace, Vincenzo; Muscoli, Carolina; Dagostino, Concetta; Giancotti, Luigino Antonio; Gliozzi, Micaela; Sacco, Iolanda; Visalli, Valeria; Gratteri, Santo; Palma, Ernesto; Malara, Natalia; Musolino, Vincenzo; Carresi, Cristina; Muscoli, Saverio; Vitale, Cristiana; Salvemini, Daniela; Romeo, Francesco

    2014-11-01

    Bioconversion of glyceryl trinitrate (GTN) into nitric oxide (NO) by aldehyde dehydrogenase-2 (ALDH-2) is a crucial mechanism which drives vasodilatory and antiplatelet effect of organic nitrates in vitro and in vivo. Oxidative stress generated by overproduction of free radical species, mostly superoxide anions and NO-derived peroxynitrite, has been suggested to play a pivotal role in the development of nitrate tolerance, though the mechanism still remains unclear. Here we studied the free radical-dependent impairment of ALDH-2 in platelets as well as vascular tissues undergoing organic nitrate ester tolerance and potential benefit when using the selective peroxynitrite decomposition catalyst Mn(III) tetrakis (4-Benzoic acid) porphyrin (MnTBAP). Washed human platelets were made tolerant to nitrates via incubation with GTN for 4h. This was expressed by attenuation of platelet aggregation induced by thrombin (40U/mL), an effect accompanied by GTN-related induction of cGMP levels in platelets undergoing thrombin-induced aggregation. Both effects were associated to attenuated GTN-induced nitrite formation in platelets supernatants and to prominent nitration of ALDH-2, the GTN to NO metabolizing enzyme, suggesting that GTN tolerance was associated to reduced NO formation via impairment of ALDH-2. These effects were all antagonized by co-incubation of platelets with MnTBAP, which restored GTN-induced responses in tolerant platelets. Comparable effect was found under in in vivo settings. Indeed, MnTBAP (10mg/kg, i.p.) significantly restored the hypotensive effect of bolus injection of GTN in rats made tolerants to organic nitrates via chronic administration of isosorbide-5-mononitrate (IS-5-MN), thus confirming the role of peroxynitrite overproduction in the development of tolerance to vascular responses induced by organic nitrates. In conclusion, oxidative stress subsequent to prolonged use of organic nitrates, which occurs via nitration of ALDH-2, represents a key event

  2. Radon and aldehyde concentrations in the indoor environment. Final report

    International Nuclear Information System (INIS)

    Findings regarding indoor air contaminants in the energy-efficient residence (EER) in Mt. Airy, Maryland are reported. The objectives of the study were to collect and analyze relevant air quality samples (specifically radon and aldehydes), characterize the indoor air quality with respect to radon and aldehydes, and develop relationships between air infiltration rates and contaminant levels. One-fifth of the measured formaldehyde concentrations were in the range that may cause health concerns. Although indoor temperature and relative humidity affect indoor HCHO concentration, the elevated formaldehyde concentrations were measured under very low air infiltration rates. The data show that ventilation of the indoor air space is somewhat effective in reducing high HCHO concentrations. The operation of the heat exchanger led to an increase of the air infiltration rate which in turn resulted in substantial reduction of formaldehyde concentrations. A considerable number of the collected samples of indoor air displayed radon concentrations at levels higher than 1.0 to 4.0 nCim-3 (assuming an equilibrium factor of 0.5, these radon levels would correspond to working levels above the health guidelines suggested by the US EPA for homes in Florida built on land reclaimed from phosphate mining). As in the case of indoor formaldehyde concentrations, elevated indoor concentrations are substantially reduced when the infiltration rate is increased. The data base shows that the use of the air to air heat exchanger leads to reduction of indoor radon concentration by increasing the residential ventilation rate

  3. Iodine-Catalyzed Prins Cyclization of Homoallylic Alcohols and Aldehydes

    Directory of Open Access Journals (Sweden)

    Luiz F. Silva

    2013-09-01

    Full Text Available The iodine-catalyzed Prins cyclization of homoallylic alcohols and aldehydes was investigated under metal-free conditions and without additives. Anhydrous conditions and inert atmosphere are not required. The reaction of 2-(3,4-dihydronaphthalen-1-ylpropan-1-ol and 21 aldehydes (aliphatic and aromatic in CH2Cl2 in the presence of 5 mol % of iodine gave 1,4,5,6-tetrahydro-2H-benzo[f]isochromenes in 54%–86% yield. Under similar conditions, the Prins cyclization of six alcohols containing an endocyclic double bond (primary, secondary, or tertiary led to dihydropyrans in 52%–91% yield. The acyclic homoallylic alcohols gave 4-iodo-tetrahydropyran in 29%–41% yield in the presence of 50 mol % of iodine. This type of substrate is the main limitation of the methodology. The relative configuration of the products was assigned by NMR and X-ray analysis. The mechanism and the ratio of the products are discussed, based on DFT calculations.

  4. Aldehyde dehydrogenase 1a3 defines a subset of failing pancreatic β cells in diabetic mice.

    Science.gov (United States)

    Kim-Muller, Ja Young; Fan, Jason; Kim, Young Jung R; Lee, Seung-Ah; Ishida, Emi; Blaner, William S; Accili, Domenico

    2016-01-01

    Insulin-producing β cells become dedifferentiated during diabetes progression. An impaired ability to select substrates for oxidative phosphorylation, or metabolic inflexibility, initiates progression from β-cell dysfunction to β-cell dedifferentiation. The identification of pathways involved in dedifferentiation may provide clues to its reversal. Here we isolate and functionally characterize failing β cells from various experimental models of diabetes and report a striking enrichment in the expression of aldehyde dehydrogenase 1 isoform A3 (ALDH(+)) as β cells become dedifferentiated. Flow-sorted ALDH(+) islet cells demonstrate impaired glucose-induced insulin secretion, are depleted of Foxo1 and MafA, and include a Neurogenin3-positive subset. RNA sequencing analysis demonstrates that ALDH(+) cells are characterized by: (i) impaired oxidative phosphorylation and mitochondrial complex I, IV and V; (ii) activated RICTOR; and (iii) progenitor cell markers. We propose that impaired mitochondrial function marks the progression from metabolic inflexibility to dedifferentiation in the natural history of β-cell failure. PMID:27572106

  5. Enhanced direct electron transfer between laccase and hierarchical carbon microfibers/carbon nanotubes composite electrodes. Comparison of three enzyme immobilization methods

    International Nuclear Information System (INIS)

    Three immobilization protocols were investigated with respect to direct electron transfer between hierarchical carbon microfibers/carbon nanotubes composite material on graphite rod electrodes and Trametes hirsuta laccase. Immobilization was done by covalent binding of laccase to aminophenyl-modified electrodes via amide-bond formation with carboxylic acid residues or imino-bond formation with aldehyde groups introduced by oxidation of sugar residues of the enzyme's glycosylation shell. Moreover, immobilization was achieved by adsorbing laccase to electrodes hydrophilized with pyrene-hexanoic acid. High current densities for biocatalytic oxygen reduction were obtained for all immobilization strategies. The formation of the imino bonds let to the binding of laccase in close to 100% direct electron transfer configuration and consequently to the highest oxygen reduction currents.

  6. Vitamin E and C supplementation reduces oxidative stress, improves antioxidant enzymes and positive muscle work in chronically loaded muscles of aged rats

    OpenAIRE

    Ryan, Michael J.; Dudash, Holly J.; Docherty, Megan; Geronilla, Kenneth B.; Baker, Brent A.; Haff, G. Gregory; Cutlip, Robert G; Alway, Stephen E.

    2010-01-01

    Aging is associated with increased oxidative stress. Muscle levels of oxidative stress are further elevated with exercise. The purpose of this study was to determine if dietary antioxidant supplementation would improve muscle function and cellular markers of oxidative stress in response to chronic repetitive loading in aging. The dorsiflexors of the left limb of aged and young adult Fischer 344 Brown x Norway rats were loaded 3 times weekly for 4.5 weeks using 80 maximal stretch-shortening co...

  7. Role of the Molybdoflavoenzyme Aldehyde Oxidase Homolog 2 in the Biosynthesis of Retinoic Acid: Generation and Characterization of a Knockout Mouse▿ †

    Science.gov (United States)

    Terao, Mineko; Kurosaki, Mami; Barzago, Maria Monica; Fratelli, Maddalena; Bagnati, Renzo; Bastone, Antonio; Giudice, Chiara; Scanziani, Eugenio; Mancuso, Alessandra; Tiveron, Cecilia; Garattini, Enrico

    2009-01-01

    The mouse aldehyde oxidase AOH2 (aldehyde oxidase homolog 2) is a molybdoflavoenzyme. Harderian glands are the richest source of AOH2, although the protein is detectable also in sebaceous glands, epidermis, and other keratinized epithelia. The levels of AOH2 in the Harderian gland and skin are controlled by genetic background, being maximal in CD1 and C57BL/6 and minimal in DBA/2, CBA, and 129/Sv strains. Testosterone is a negative regulator of AOH2 in Harderian glands. Purified AOH2 oxidizes retinaldehyde into retinoic acid, while it is devoid of pyridoxal-oxidizing activity. Aoh2−/− mice, the first aldehyde oxidase knockout animals ever generated, are viable and fertile. The data obtained for this knockout model indicate a significant role of AOH2 in the local synthesis and biodisposition of endogenous retinoids in the Harderian gland and skin. The Harderian gland's transcriptome of knockout mice demonstrates overall downregulation of direct retinoid-dependent genes as well as perturbations in pathways controlling lipid homeostasis and cellular secretion, particularly in sexually immature animals. The skin of knockout mice is characterized by thickening of the epidermis in basal conditions and after UV light exposure. This has correlates in the corresponding transcriptome, which shows enrichment and overall upregulation of genes involved in hypertrophic responses. PMID:18981221

  8. A Novel NADPH-Dependent Aldehyde Reductase Gene from Saccharomyces cerevisiae NRRL Y-12632 Involved in the Detoxification of Aldehyde Inhibitors Derived from Lignocellulosic Biomass Conversion

    Science.gov (United States)

    Aldehyde inhibitors such as furfural, 5-hydroxymethylfurfural (HMF), anisaldehyde, benzaldehyde, cinnamaldehyde, and phenylaldehyde are commonly generated during lignocellulosic biomass conversion process for low-cost cellulosic ethanol production that interferes with subsequent microbial growth and...

  9. Effect of various chemicals on the aldehyde dehydrogenase activity of the rat liver cytosol.

    Science.gov (United States)

    Marselos, M; Vasiliou, V

    1991-01-01

    The cytosolic activity of aldehyde dehydrogenase (ALDH) was studied in the rat liver, after acute administration of various carcinogenic and chemically related compounds. Male Wistar rats were treated with 27 different chemicals, including polycyclic aromatic hydrocarbons, aromatic amines, nitrosamines, azo dyes, as well as with some known direct-acting carcinogens. The cytosolic ALDH activity of the liver was determined either with propionaldehyde and NAD (P/NAD), or with benzaldehyde and NADP (B/NADP). The activity of ALDH remained unaffected after treatment with 1-naphthylamine, nitrosamines and also with the direct-acting chemical carcinogens tested. On the contrary, polycyclic aromatic hydrocarbons, polychlorinated biphenyls (Arochlor 1254) and 2-naphthylamine produced a remarkable increase of ALDH. In general, the response to the effectors was disproportionate between the two types of enzyme activity, being much in favour for the B/NADP activity. This fact resulted to an inversion of the ratio B/NADP vs. P/NAD, which under constitutive conditions is lower than 1. In this respect, the most potent compounds were found to be polychlorinated biphenyls, 3-methylcholanthrene, benzo(a)pyrene and 1,2,5,6-dibenzoanthracene. Our results suggest that the B/NADP activity of the soluble ALDH is greatly induced after treatment with compounds possessing aromatic ring(s) in their molecule. It is not known, if this response of the hepatocytes is related with the process of chemical carcinogenesis. PMID:2060039

  10. Aldehyde dehydrogenase 2 is associated with cognitive functions in patients with Parkinson’s disease

    Science.gov (United States)

    Yu, Rwei-Ling; Tan, Chun-Hsiang; Lu, Ying-Che; Wu, Ruey-Meei

    2016-01-01

    Neurotransmitter degradation has been proposed to cause the accumulation of neurotoxic metabolites. The metabolism of these metabolites involves aldehyde dehydrogenase 2 (ALDH2). The Asian-specific single nucleotide polymorphism rs671 causes reduced enzyme activity. This study aims to explore whether Parkinson’s disease (PD) patients with reduced ALDH2 activity owing to the rs671 polymorphism are at risk for neuropsychological impairments. A total of 139 PD patients were recruited. Each participant was assessed for medical characteristics and their ALDH2 genotype. The Mini-Mental State Examination (MMSE), the Clinical Dementia Rating Scale and the Frontal Behavioral Inventory were used to measure neuropsychological functions. We found that the MMSE scores were significantly lower in patients with inactive ALDH2 (U = 1873.5, p = 0.02). The presence of cognitive impairments was significantly more frequent in the inactive ALDH2 group (46.0%) than in the active ALDH2 group (26.3%) (χ2 = 5.886, p = 0.01). The inactive group showed significant deterioration in hobbies and exhibited more severe “disorganization” and “hyper-sexuality” behaviours. The additive effects of the allele on the development of cognitive impairments in PD patients may be an important finding that provides further insight into the pathogenic mechanism of cognitive dysfunction in PD. PMID:27453488

  11. Threshold responses in cinnamic-aldehyde-sensitive subjects: results and methodological aspects

    DEFF Research Database (Denmark)

    Johansen, J D; Andersen, Klaus Ejner; Rastogi, S C;

    1996-01-01

    Cinnamic aldehyde is an important fragrance material and contact allergen. The present study was performed to provide quantitative data on the eliciting capacity of cinnamic aldehyde, to be considered in assessment of clinical relevance and health hazard. The skin response to serial dilution patc...

  12. Direct chemoselective synthesis of glyconanoparticles from unprotected reducing glycans and glycopeptide aldehydes

    DEFF Research Database (Denmark)

    Thygesen, Mikkel Boas; Sørensen, Kasper Kildegaard; Cló, Emiliano;

    2009-01-01

    Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell.......Chemoselective oxime coupling was used for facile conjugation of unprotected, reducing glycans and glycopeptide aldehydes with core-shell gold nanoparticles carrying reactive aminooxy groups on the organic shell....

  13. Draft Genome Sequence of Aldehyde-Degrading Strain Halomonas axialensis ACH-L-8

    OpenAIRE

    Ye, Jun; Ren, Chong; Shan, Xiexie; Zeng, Runying

    2016-01-01

    Halomonas axialensis ACH-L-8, a deep-sea strain isolated from the South China Sea, has the ability to degrade aldehydes. Here, we present an annotated draft genome sequence of this species, which could provide fundamental molecular information on the aldehydes-degrading mechanism.

  14. Draft Genome Sequence of Aldehyde-Degrading Strain Halomonas axialensis ACH-L-8.

    Science.gov (United States)

    Ye, Jun; Ren, Chong; Shan, Xiexie; Zeng, Runying

    2016-01-01

    Halomonas axialensisACH-L-8, a deep-sea strain isolated from the South China Sea, has the ability to degrade aldehydes. Here, we present an annotated draft genome sequence of this species, which could provide fundamental molecular information on the aldehydes-degrading mechanism. PMID:27081145

  15. The importance of antioxidants which play the role in cellular response against oxidative/nitrosative stress: current state.

    Science.gov (United States)

    Kurutas, Ergul Belge

    2016-01-01

    Remarkable interest has risen in the idea that oxidative/nitrosative stress is mediated in the etiology of numerous human diseases. Oxidative/Nitrosative stress is the result of an disequilibrium in oxidant/antioxidant which reveals from continuous increase of Reactive Oxygen and Reactive Nitrogen Species production. The aim of this review is to emphasize with current information the importance of antioxidants which play the role in cellular responce against oxidative/nitrosative stress, which would be helpful in enhancing the knowledge of any biochemist, pathophysiologist, or medical personnel regarding this important issue. Products of lipid peroxidation have commonly been used as biomarkers of oxidative/nitrosative stress damage. Lipid peroxidation generates a variety of relatively stable decomposition end products, mainly α, β-unsaturated reactive aldehydes, such as malondialdehyde, 4-hydroxy-2-nonenal, 2-propenal (acrolein) and isoprostanes, which can be measured in plasma and urine as an indirect index of oxidative/nitrosative stress. Antioxidants are exogenous or endogenous molecules that mitigate any form of oxidative/nitrosative stress or its consequences. They may act from directly scavenging free radicals to increasing antioxidative defences. Antioxidant deficiencies can develop as a result of decreased antioxidant intake, synthesis of endogenous enzymes or increased antioxidant utilization. Antioxidant supplementation has become an increasingly popular practice to maintain optimal body function. However, antoxidants exhibit pro-oxidant activity depending on the specific set of conditions. Of particular importance are their dosage and redox conditions in the cell. PMID:27456681

  16. An Investigation of Measuring Apparatus for Vo_2 During Exercise,and Effects of 10-week Exercise Training on Aerobic Work Capacity,Body Composition and Oxidative Enzymes in Skeletal Muscle in Obese-Diabetic Model OLETF Rats

    OpenAIRE

    Suzuki, Masato; Seino, Tetsuya; Kimura, Masaki; Hodumi, Noriko; Terada, Shin; Higuchi, Mitsuru; Shibasaki, Toshiaki

    2005-01-01

    SUZUKI, M., SEINO, T., KIMURA, M., HODUMI, N., TERADA, S., HIGUCHI, M., and SHIBASAKI, T. An Investigation of Measuring Appatratus for VO2 During Exercise, and Effects of 10-week Exercise Training on Aerobic Work Capacity, Body Composition and Oxidative Enzymes in Skeletal Muscle in Obese-Diabetic Model OLETF Rats. Abv. Exerc. Sports Physiol., Vol.11, No.1 pp.21-31, 2005. This study was conducted to develop an open-cicuit metabolic apparatus equipped with a treadmill for obese-diabetic model ...

  17. O3浓度升高和UV-B辐射增强对大豆叶片抗氧化酶活性及POD同工酶的影响%Combined Effects of Elevated O3 Concentration and UV-B Radiation on Anti-Oxidative Enzymes Activities and POD Enzymes Isozymes of Soybean

    Institute of Scientific and Technical Information of China (English)

    刘轶鸥; 王岩; 刘波; 杨兴; 赵天宏

    2013-01-01

    During the last several decades, significant reductions in the concentrations of stratospheric ozone( O3) have been reported. The decrease of ozone concentration causes an increment of ultraviolet-B radiation to earth surface. The objective of this experiment is to reveal the toxicological mechanism under elevated ozone concentration and UV-B radiation singly or in combination on plant anti-oxidation enzymes activities and POD isoenzyme. Open-top chambers ( OTCs) were utilized to investigate change of anti-oxidation enzymes activities and POD isoenzyme band in soybean( Glycine max) leaves under elevated ozone concentration and UV-B radiation singly or in combination treatment. The results of anti-oxidation enzymes activities indicated that either O3 treatment or UV-B treatment induced a decrease on SOD,POD and CAT,and in the combined stress,anti-oxidation enzymes activities had intensified this trend to a certain degree. The result of POD isozyme band showed that a new band appeared under O3 treatment in branching stage and two new bands appeared in flowering stage and podding stage compared of branching stage,and the shade of color of POD isoenzyme bands was lighter compared to CK treatment. It was suggested that in all growth period,POD isoenzyme activity was inhibited under combined stress.%以大豆品种铁丰29为材料,利用开顶式气室(OTCs)研究了O3浓度升高和UV-B辐射增强单独胁迫及复合胁迫下大豆叶片抗氧化酶(SOD、POD和CAT)活性及POD同工酶谱带的变化.结果表明:O3处理大豆叶片SOD、CAT和POD活性均低于对照;UV处理下,大豆叶片SOD、CAT、POD活性也均低于对照,但基本高于O3处理;O3及UV复合处理下,加剧了SOD、CAT、POD活性的减弱.对POD同工酶研究发现,在分枝期,O3处理产生Ⅰ条新谱带,开花期和结荚期均比分枝期多2条谱带,并且受胁迫处理的POD酶谱带与对照相比颜色较浅,说明在整个生育期,胁迫处理下的大豆叶片POD同工酶活性受到抑制.

  18. Synthesis of bio-based aldehyde from seaweed polysaccharide and its interaction with bovine serum albumin.

    Science.gov (United States)

    Kholiya, Faisal; Chaudhary, Jai Prakash; Vadodariya, Nilesh; Meena, Ramavatar

    2016-10-01

    Here, we demonstrate a successful synthesis of bio-based aldehyde namely dialdehyde-carboxymethylagarose (DCMA) using carboxymethyagarose (CMA). Further reaction parameters (i.e. reaction temperature, pH and periodate concentration) were optimized to achieve maximum aldehyde content and product yield. The synthesis of DCMA was confirmed by employing FTIR, (1)H NMR, XRD, SEM, AFM, TGA, DSC, EA and GPC techniques. To investigate the aldehyde functionality, DCMA was allowed to interact with BSA and obtained results were found to be comparable with that of synthetic aldehyde (Formaldehyde). Further interaction of DCMA with BSA was confirmed by using UV-vis, FTIR, fluorescent spectroscopy, CD and DLS analysis. Results of this study revealed that bio-based aldehyde behaves like formaldehyde. This study adds value to abundant marine biopolymers and opens the new research area for polymer researchers. PMID:27312639

  19. Aldehyde dehydrogenases inhibition eradicates leukemia stem cells while sparing normal progenitors.

    Science.gov (United States)

    Venton, G; Pérez-Alea, M; Baier, C; Fournet, G; Quash, G; Labiad, Y; Martin, G; Sanderson, F; Poullin, P; Suchon, P; Farnault, L; Nguyen, C; Brunet, C; Ceylan, I; Costello, R T

    2016-01-01

    The vast majority of patients with acute myeloid leukemia (AML) achieve complete remission (CR) after standard induction chemotherapy. However, the majority subsequently relapse and die of the disease. A leukemia stem cell (LSC) paradigm has been invoked to explain this failure of CR to reliably translate into cure. Indeed, LSCs are highly enriched in CD34+CD38- leukemic cells that exhibit positive aldehyde dehydrogenase activity (ALDH+) on flow cytometry, these LSCs are resistant to currently existing treatments in AML such as cytarabine and anthracycline that, at the cost of great toxicity on normal cells, are highly active against the leukemic bulk, but spare the LSCs responsible for relapse. To try to combat the LSC population selectively, a well-characterized ALDH inhibitor by the trivial name of dimethyl ampal thiolester (DIMATE) was assessed on sorted CD34+CD38- subpopulations from AML patients and healthy patients. ALDH activity and cell viability were monitored by flow cytometry. From enzyme kinetic studies DIMATE is an active enzyme-dependent, competitive, irreversible inhibitor of ALDH1. On cells in culture, DIMATE is a powerful inhibitor of ALDHs 1 and 3, has a major cytotoxic activity on human AML cell lines. Moreover, DIMATE is highly active against leukemic populations enriched in LSCs, but, unlike conventional chemotherapy, DIMATE is not toxic for healthy hematopoietic stem cells which retained, after treatment, their self-renewing and multi-lineage differentiation capacity in immunodeficient mice, xenografted with human leukemic cells. DIMATE eradicates specifically human AML cells and spares healthy mouse hematologic cells. PMID:27611922

  20. Xanthine dehydrogenase and aldehyde oxidase impact plant hormone homeostasis and affect fruit size in 'Hass' avocado.

    Science.gov (United States)

    Taylor, Nicky J; Cowan, A Keith

    2004-04-01

    The contribution of xanthine dehydrogenase (XDH, EC 1.1.1.204) to fruit size was investigated using the normal and small-fruit variants of Persea americana Mill. cv. 'Hass'. Inhibition of XDH by treatment of normal fruit, in the linear phase of growth (phase II), with allopurinol (Allo) arrested fruit growth. Adenine (Ade), a less effective inhibitor of this enzyme, also arrested fruit growth when applied in phase II and slowed fruit growth when applied in phase III. A time-course study on the activity of XDH in mesocarp tissue from normal and small fruit showed that maximum activity occurred late in phase II and that the peak in activity was absent in mesocarp of the small fruit. Feeding Ade to growing fruit in phase III caused a transient decline in fruit growth (measured as change in fruit length). Thereafter, growth resumed although fruit size was irreversibly affected. Treatment of fruit with Ade and Ade-containing cytokinins altered activity of another molybdenum enzyme, aldehyde oxidase (EC 1.2.3.1). Cytokinin oxidase was induced by cytokinin and auxin. Purine catabolism via hypoxanthine/xanthine was operative in normal fruit and in mesocarp from the small-fruit variant and as expected, Allo treatment caused accumulation of xanthine and adenine. In the absence of an increase in XDH during growth of the small-fruit phenotype, low levels of Ade were interpreted as resulting from respiration-enhanced adenylate depletion. Stress and/or pathogen induction of the alternative oxidase pathway is proposed as a possible cause.

  1. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2013. Scientific Opinion on Flavouring Group Evaluation 72, Revision 1 (FGE.72Rev1): Consideration of aliphatic, branched-chain saturated and unsaturated alcohols, aldehydes, acids, and related esters evaluated by the JECFA (61st meeting) structurally related to branched- and straight-chain unsaturated carboxylic acids, esters of these and straight-chain aliphatic saturated alcohols evaluated by EFSA in FGE.05Rev2

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz;

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further......” based on the MSDI approach. Besides the safety assessment of these flavouring substances, the specifications for the materials of commerce have also been considered and for all 23 substances, the information is adequate...

  2. DNA-Templated Introduction of an Aldehyde Handle in Proteins

    DEFF Research Database (Denmark)

    Kodal, Anne Louise Bank; Rosen, Christian Bech; Mortensen, Michael Rosholm;

    2016-01-01

    Many medical and biotechnological applications rely on labeling of proteins, but one key challenge is the production of homogeneous and site-specific conjugates. This can rarely be achieved by mere residue-specific random labeling, but requires genetic engineering. Using site-selective DNA......-templated reductive amination we create DNA-protein conjugates with control over labeling stoichiometry without genetic engineering. A guiding DNA strand with a metal-binding functionality facilitates site-selectivity by directing coupling of a second reactive DNA strand to the vicinity of a protein metal......-binding site. Here, we demonstrate DNA-templated reductive amination for His6-tagged proteins and native metal-binding proteins, including IgG1 antibodies. We also use a cleavable linker between the DNA and the protein to remove the DNA and introduce a single aldehyde to proteins. This functions as a handle...

  3. Monolayer structures of alkyl aldehydes: Odd-membered homologues

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, T.K. [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Clarke, S.M., E-mail: stuart@bpi.cam.ac.u [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Bhinde, T. [BP Institute, Department of Chemistry, University of Cambridge, Cambridge (United Kingdom); Castro, M.A.; Millan, C. [Instituto Ciencia de los Materiales de Sevilla, Departamento de Quimica Inorganica (CSIC-Universidad de Sevilla) (Spain); Medina, S. [Centro de Investigacion, Tecnologia e Innovacion de la Universidad de Sevilla (CITIUS), Sevilla (Spain)

    2011-03-01

    Crystalline monolayers of three aldehydes with an odd number of carbon atoms in the alkyl chain (C{sub 7}, C{sub 9} and C{sub 11}) at low coverages are observed by a combination of X-ray and neutron diffraction. Analysis of the diffraction data is discussed and possible monolayer crystal structures are proposed; although unique structures could not be ascertained for all molecules. We conclude that the structures are flat on the surface, with the molecules lying in the plane of the layer. The C{sub 11} homologue is determined to have a plane group of either p2, pgb or pgg, and for the C{sub 7} homologue the p2 plane group is preferred.

  4. Reduction of Aldehydes and Ketones with Potassium Borohydride as Reductant

    Institute of Scientific and Technical Information of China (English)

    罗慧谋; 李毅群

    2005-01-01

    A series of aldehydes and ketones were reduced by potassium borohydride in an ionic liquid/water ([bmim]PF6/H2O) biphasic system to afford corresponding alcohol with high purity in excellent yields. The ionic liquid/water biphasic system could promote the chemoselectivity and the substituents such as nitro group and chlorine remained intact. Aromatic ketones were not as active as aromatic aldhydes and cyclic ketones owing to their higher steric hindrance. The ionic liquid could be recycled and reused. This protocol has notable advantages of no need of phase transfer catalyst and organic solvents, mild conditions, simple operation, short reaction time, ease work-up, high yields and recycling of the ionic liquid.

  5. Food Enzymes

    Science.gov (United States)

    McBroom, Rachel; Oliver-Hoyo, Maria T.

    2007-01-01

    Many students view biology and chemistry as two unrelated, separate sciences; how these courses are generally taught in high schools may do little to change that impression. The study of enzymes provide a great opportunity for both biology and chemistry teachers to share with students the interdisciplinary nature of science. This article describes…

  6. Enzyme immunoassay

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, B; Dinesen, B; Deckert, M

    1985-01-01

    An enzyme linked immunoadsorbent assay for urinary albumin using commercially available reagents is described. The assay range is 2.5-120 micrograms/l. When samples are analysed in two standard dilutions, the assayable albumin concentration range is 2.5-240 mg/l, covering the clinical range from...

  7. Pharmacological activities of cilantro's aliphatic aldehydes against Leishmania donovani.

    Science.gov (United States)

    Donega, Mateus A; Mello, Simone C; Moraes, Rita M; Jain, Surendra K; Tekwani, Babu L; Cantrell, Charles L

    2014-12-01

    Leishmaniasis is a chronic infectious disease caused by different Leishmania species. Global occurrences of this disease are primarily limited to tropical and subtropical regions. Treatments are available; however, patients complain of side effects. Different species of plants have been screened as a potential source of new drugs against leishmaniasis. In this study, we investigated the antileishmanial activity of cilantro (Coriandrum sativum) essential oil and its main components: (E)-2-undecenal, (E)-2-decenal, (E)-2-dodecenal, decanal, dodecanal, and tetradecanal. The essential oil of C. sativum leaves inhibits growth of Leishmani donovani promastigotes in culture with an IC50 of 26.58 ± 6.11 µg/mL. The aliphatic aldehydes (E)-2-decenal (7.85 ± 0.28 µg/mL), (E)-2-undecenal (2.81 ± 0.21 µg/mL), and (E)-2-dodecenal (4.35 ± 0.15 µg/mL), all isolated from C. sativum essential oil, are effective inhibitors of in vitro cultures of L. donovani promastigotes. Aldehydes (E)-2-decenal, (E)-2-undecenal, and (E)-2-dodecenal were also evaluated against axenic amastigotes and IC50 values were determined to be 2.47 ± 0.25 µg/mL, 1.25 ± 0.11 µg/mL, and 4.78 ± 1.12 µg/mL, respectively. (E)-2-Undecenal and (E)-2-dodecenal demonstrated IC50 values of 5.65 ± 0.19 µg/mL and 9.60 ± 0.89 µg/mL, respectively, against macrophage amastigotes. These cilantro compounds showed no cytotoxicity against THP-1 macrophages. PMID:25340465

  8. Quantification of Carnosine-Aldehyde Adducts in Human Urine.

    Science.gov (United States)

    da Silva Bispo, Vanderson; Di Mascio, Paolo; Medeiros, Marisa

    2014-10-01

    Lipid peroxidation generates several reactive carbonyl species, including 4-hydroxy-2-nonenal (HNE), acrolein (ACR), 4-hydroxy-2-hexenal (HHE) and malondialdehyde. One major pathwayof aldehydes detoxification is through conjugation with glutathione catalyzed by glutathione-S-transferases or, alternatively, by conjugation with endogenous histidine containing dipeptides, such as carnosine (CAR). In this study, on-line reverse-phase high-performance liquid chromatography (HPLC) separation with tandem mass spectrometry detection was utilized for the accurate quantification of CAR- ACR, CAR-HHE and CAR-HNE adducts in human urinary samples from non-smokers young adults. Standard adducts were prepared and isolated by HPLC. The results showed the presence of a new product from the reaction of CAR with ACR. This new adduct was completely characterized by HPLC/MS-MSn, 1H RMN, COSY and HSQC. The new HPLC/MS/MS methodology employing stable isotope-labeled internal standards (CAR-HHEd5 and CAR-HNEd11) was developed for adducts quantification. This methodology permits quantification of 10pmol CAR-HHE and 1pmol of CAR-ACR and CAR-HNE. Accurate determinations in human urine sample were performed and showed 4.65±1.71 to CAR-ACR, 5.13±1.76 to CAR-HHE and 5.99±3.19nmol/mg creatinine to CAR-HNE. Our results indicate that carnosine pathways can be an important detoxification route of a, ß -unsaturated aldehydes. Moreover, carnosine adducts may be useful as redox stress indicator. PMID:26461323

  9. Acetylene hydratase of Pelobacter acetylenicus. Molecular and spectroscopic properties of the tungsten iron-sulfur enzyme.

    Science.gov (United States)

    Meckenstock, R U; Krieger, R; Ensign, S; Kroneck, P M; Schink, B

    1999-08-01

    Acetylene hydratase of Pelobacter acetylenicus is a tungsten iron-sulfur protein involved in the fermentation of acetylene to ethanol and acetate. Expression of the enzyme was increased 10-fold by feeding a 50-L batch culture continuously with 104 Pa acetylene at pH 6.8-7.0. Acetylene hydratase was purified to homogeneity by a three-step procedure in either the absence or presence of dioxygen. The enzyme was a monomer with a molecular mass of 73 kDa (SDS/PAGE) or 83 kDa (matrix-assisted laser-desorption ionization MS) and contained 0.5 +/- 0.1 W (inductively coupled plasma/MS) and 1.3 +/- 0.1 molybdopterin-guanine dinucleotide per mol. Selenium was absent. EPR spectra (enzyme as isolated, under air) showed a signal typical of a [3Fe-4S] cluster with gav = 2.01, at 10 K. In enzyme prepared under N2/H2, this signal was absent and reaction with dithionite led to a rhombic signal with gz = 2.048, gy = 1.939 and gx = 1.920 indicative of a low-potential ferredoxin-type [4Fe-4S] cluster. Upon oxidation with hexacyanoferrate(III), a new signal appeared with gx = 2.007, gy = 2.019 and gz = 2.048 (gav = 2.022), which disappeared after further oxidation. The signal was still visible at 150 K and was tentatively assigned to a W(V) center. The iron-sulfur center of acetylene hydratase (prepared under N2/H2) gave a midpoint redox potential of -410 +/- 20 mV in a spectrophotometric titration with dithionite. Enzyme activity depended on the redox potential of the solution, with 50% of maximum activity at -340 +/- 20 mV. The presence of a pterin-guanine dinucleotide cofactor differentiates acetylene hydratase from the aldehyde ferredoxin oxidoreductase-type enzymes which have a pterin mononucleotide cofactor. PMID:10447686

  10. Estimating rates of denitrification enzyme activity in wetland soils and direct simultaneous quantification of nitrogen and nitrous oxide by membrane inlet mass spectrometry

    Science.gov (United States)

    Denitrification enzyme activity (DEA) was measured in short-term (4 h) anaerobic assays using Membrane Inlet Mass Spectrometry (MIMS) and electron capture gas chromatography (GC-ECD). Using MIMS, modifications of the instrument and sample handling allowed for the simultaneous me...

  11. The longitudinal effect of the aldehyde dehydrogenase 2*2 allele on the risk for nonalcoholic fatty liver disease

    Science.gov (United States)

    Oniki, K; Morita, K; Watanabe, T; Kajiwara, A; Otake, K; Nakagawa, K; Sasaki, Y; Ogata, Y; Saruwatari, J

    2016-01-01

    Aldehyde dehydrogenase 2 (ALDH2) detoxifies toxic aldehydes and has a key role in protecting the liver. An elevated gamma-glutamyl transferase (GGT) level is related to oxidative stress and nonalcoholic fatty liver disease (NAFLD). We herein investigated the association between inactive ALDH2*2 allele (rs671) and the risk of NAFLD, including the relationship to the GGT level. A retrospective follow-up study (mean 5.4±1.1 years) was conducted among 341 Japanese health screening program participants. The receiver operating characteristic curve indicated that the GGT level predicted the development of NAFLD (area under the curve: 0.65, P<0.05) with a cutoff value of 25.5 IUl−1. The longitudinal risk of NAFLD was higher in the ALDH2*2 allele carriers than in the noncarriers (odds ratio (OR): 2.30, 95% confidence interval (CI): 1.21–4.40), and the risk was further increased among the *2 allele carriers with GGT values ⩾25.5 IUl−1 (OR: 4.28, 95% CI: 1.80–10.19). On the other hand, there were no significant changes in the subjects' body weight and body mass index during observation period. The ALDH2*2 allele, in relation to the GGT level, may potentially be a novel risk factor for NAFLD. PMID:27214654

  12. Anesthetic effects changeable in habitual drinkers: Mechanistic drug interactions with neuro-active indoleamine-aldehyde condensation products associated with alcoholic beverage consumption.

    Science.gov (United States)

    Tsuchiya, Hironori

    2016-07-01

    Clinicians often experience the reduced efficacy of general and local anesthetics and anesthesia-related drugs in habitual drinkers and chronic alcoholics. However, the mechanistic background underlying such anesthetic tolerance remains unclear. Biogenic indoleamines condense with alcohol-derived aldehydes during fermentation processes and under physiological conditions to produce neuro-active tetrahydro-β-carbolines and β-carbolines, many of which are contained not only in various alcoholic beverages but also in human tissues and body fluids. These indoleamine-aldehyde condensation products are increased in the human body because of their exogenous and endogenous supply enhanced by alcoholic beverage consumption. Since tetrahydro-β-carbolines and β-carbolines target receptors, ion channels and neuronal membranes which are common to anesthetic agents, we propose a hypothesis that they may pharmacodynamically interact at GABAA receptors, NMDA receptors, voltage-gated Na(+) channels and membrane lipid bilayers to attenuate anesthetics-induced positive allosteric GABAA receptor modulation, NMDA receptor antagonism, ion channel blockade and neuronal membrane modification, thereby affecting anesthetic efficacy. The condensation products may also cooperatively interact with ethanol that induces adaptive changes and cross-tolerance to anesthetics and with dopamine-aldehyde adducts that act on GABAA receptors and membrane lipids. Because tetrahydro-β-carbolines and β-carbolines are metabolized to lose or decrease their neuro-activities, induction of the relevant enzymes by habitual drinking could produce an inter-individual difference of drinkers in susceptibility to anesthetic agents. The present hypothesis would also provide a unified framework for different modes of anesthetic action, which are inhibited by neuro-active indoleamine-aldehyde condensation products associated with alcoholic beverage consumption. PMID:27241259

  13. Transcriptome analysis of Zymomonas mobilis ZM4 reveals mechanisms of tolerance and detoxification of phenolic aldehyde inhibitors from lignocellulose pretreatment

    OpenAIRE

    Yi, Xia; Gu, Hanqi; Gao, Qiuqiang; Liu, Z. Lewis; Bao, Jie

    2015-01-01

    Background Phenolic aldehydes generated from lignocellulose pretreatment exhibited severe toxic inhibitions on microbial growth and fermentation. Numerous tolerance studies against furfural, 5-hydroxymethyl-2-furaldehyde (HMF), acetate, and ethanol were reported, but studies on inhibition of phenolic aldehyde inhibitors are rare. For ethanologenic strains, Zymomonas mobilis ZM4 is high in ethanol productivity and genetic manipulation feasibility, but sensitive to phenolic aldehyde inhibitors....

  14. Selective Oxidation of Alcohols Using Photoactive VO@g‑C3N4

    Data.gov (United States)

    U.S. Environmental Protection Agency — A photoactive VO@g-C3N4 catalyst has been developed for the selective oxidation of alcohols to the corresponding aldehydes and ketones. The visible light mediated...

  15. Fe-Catalyzed Oxidative Cleavage of Unsaturated Fatty Acids

    OpenAIRE

    Spannring, P.

    2013-01-01

    The oxidative cleavage of unsaturated fatty acids into aldehydes or carboxylic acids gives access to valuable products. The products can be used as chemical building blocks, as emulsifiers or in the paint or polymer industry. Ozonolysis is applied industrially to cleave the fatty acid oleic acid into the aldehydes nonanal and 9-oxo-nonanoic acid or into pelargonic and azelaic acid. Considerable hazards, including explosion risks, are associated with the use of ozone, and alternative processes...

  16. Alkylating enzymes.

    Science.gov (United States)

    Wessjohann, Ludger A; Keim, Jeanette; Weigel, Benjamin; Dippe, Martin

    2013-04-01

    Chemospecific and regiospecific modifications of natural products by methyl, prenyl, or C-glycosyl moieties are a challenging and cumbersome task in organic synthesis. Because of the availability of an increasing number of stable and selective transferases and cofactor regeneration processes, enzyme-assisted strategies turn out to be promising alternatives to classical synthesis. Two categories of alkylating enzymes become increasingly relevant for applications: firstly prenyltransferases and terpene synthases (including terpene cyclases), which are used in the production of terpenoids such as artemisinin, or meroterpenoids like alkylated phenolics and indoles, and secondly methyltransferases, which modify flavonoids and alkaloids to yield products with a specific methylation pattern such as 7-O-methylaromadendrin and scopolamine.

  17. The oxidation of yeast alcohol dehydrogenase-1 by hydrogen peroxide in vitro.

    Science.gov (United States)

    Men, Lijie; Wang, Yinsheng

    2007-01-01

    Yeast alcohol dehydrogenase (YADH) plays an important role in the conversion of alcohols to aldehydes or ketones. YADH-1 is a zinc-containing protein, and it accounts for the major part of ADH activity in growing baker's yeast. To gain insight into how oxidative modification of the enzyme affects its function, we exposed YADH-1 to hydrogen peroxide in vitro and assessed the oxidized protein by LC-MS/MS analysis of proteolytic cleavage products of the protein and by measurements of enzymatic activity, zinc release, and thiol/thiolate loss. The results illustrated that Cys43 and Cys153, which reside at the active site of the protein, could be selectively oxidized to cysteine sulfinic acid (Cys-SO2H) and cysteine sulfonic acid (Cys-SO3H). In addition, H2O2 induced the formation of three disulfide bonds: Cys43-Cys153 in the catalytic domain, Cys103-Cys111 in the noncatalytic zinc center, and Cys276-Cys277. Therefore, our results support the notion that the oxidation of cysteine residues in the zinc-binding domain of proteins can go beyond the formation of disulfide bond(s); the formation of Cys-SO2H and Cys-SO3H is also possible. Furthermore, most methionines could be oxidized to methionine sulfoxides. Quantitative measurement results revealed that, among all the cysteine residues, Cys43 was the most susceptible to H2O2 oxidation, and the major oxidation products of this cysteine were Cys-SO2H and Cys-SO3H. The oxidation of Cys43 might be responsible for the inactivation of the enzyme upon H2O2 treatment.

  18. Engineering enzymes

    OpenAIRE

    Dutton, P. Leslie; Moser, Christopher C.

    2011-01-01

    Fundamental research into bioinorganic catalysis of the kind presented at this Faraday Discussion has the potential to turn inspiration drawn from impressive natural energy and chemical transformations into artificial catalyst constructions useful to mankind. Creating bio-inspired artificial constructions requires a level of understanding well beyond simple description of structures and mechanisms of natural enzymes. To be useful, such description must be augmented by a practical sense of str...

  19. Neuroprotective effects of protocatechuic aldehyde against neurotoxin-induced cellular and animal models of Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Xin Zhao

    Full Text Available Protocatechuic aldehyde (PAL has been reported to bind to DJ-1, a key protein involved in Parkinson's disease (PD, and exerts potential neuroprotective effects via DJ-1 in SH-SY5Y cells. In this study, we investigated the neuroprotective pharmacological effects of PAL against neurotoxin-induced cell and animal models of PD. In cellular models of PD, PAL markedly increased cell viability rates, mitochondrial oxidation-reduction activity and mitochondrial membrane potential, and reduced intracellular ROS levels to prevent neurotoxicity in PC12 cells. In animal models of PD, PAL reduced the apomorphine injection, caused turning in 6-OHDA treated rats, and increased the motor coordination and stride decreases in MPTP treated mice. Meanwhile, in an MPTP mouse model, PAL prevented a decrease of the contents of dopamine (DA and its metabolites in the striatum and TH-positive dopaminergic neuron loss in the substantia nigra (SN. In addition, PAL increased the protein expression of DJ-1 and reduced the level of α-synuclein in the SN of MPTP lesioned mice. PAL also increased the spine density in hippocampal CA1 neurons. The current study demonstrates that PAL can efficiently protect dopaminergic neurons against neurotoxin injury in vitro and in vivo, and that the potential mechanisms may be related to its effects in increasing DJ-1, decreasing α-synuclein and its growth-promoting effect on spine density.

  20. α,β-Unsaturated aldehyde of hyaluronan--Synthesis, analysis and applications.

    Science.gov (United States)

    Buffa, Radovan; Šedová, Petra; Basarabová, Ivana; Moravcová, Martina; Wolfová, Lucie; Bobula, Tomáš; Velebný, Vladimír

    2015-12-10

    Hyaluronic acid (HA) modified with an aldehyde group (HA-CHO or HA-aldehyde) has been extensively used for various biomedical applications. The main advantage of the aldehyde moieties is the ability to react with a wide range of amino compounds under physiological conditions. Reactions of aldehydes with primary amines in water are reversible and equilibrium is thoroughly shifted towards starting aldehyde and amine. This work presents an unique modification of HA: α,β-unsaturated aldehyde of HA (4,5-anhydro-6(GlcNAc)-oxo HA or ΔHA-CHO), which allows the primary amines to be attached to HA more effectively in comparison to the saturated HA-CHO. Higher hydrolytic stability is caused by the conjugation of imine with an adjacent --C=C-- double bond. Two strategies for the preparation of unsaturated HA-aldehyde were developed and chemical structures were studied in details. Cross-linked materials prepared from this precursor are biocompatible and suitable for applications in drug delivery and regenerative medicine. PMID:26428127