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Sample records for methyl esterase activity

  1. Pectin methyl esterase activity in apple and orange pulps

    International Nuclear Information System (INIS)

    Abdullaev, A.; Djumaev, B.B.; Djumaev, N.B.; Mukhidinov, Z.K.

    2008-01-01

    The results of pectin methyl esterase activity from apple, orange pulp and orange peel depending of ph and temperature are discussed. It's shown that the methyl esterase activity form apple and orange pulps higher in range of temperatures from +37...+60 d ig C . The analysis of dependence of its activity from ph has shown that in both case the enzyme activity increase with increase of ph

  2. Activity of pectin methyl esterase during blanching of peaches

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Rodis, P.S.; Hertog, M.L.A.T.M.; Proxenia, N.; Dijk, van C.

    1999-01-01

    The activity of pectin methyl esterase (PE) in peaches during blanching treatments was modelled and analyzed. It was postulated that the enzyme exists in two configurations, one bound and one soluble. The bound configuration can be converted into the soluble configuration. These two configurations

  3. Inhibition of Pectin Methyl Esterase Activity By Green Tea Catechins

    OpenAIRE

    Sagi, Irit; Lewis, Kristin; Tworowski, Dmitry; Shahar, Chen; Selzer, Tzvia

    2008-01-01

    Pectin methyl esterases (PMEs) and their endogenous inhibitors are involved in the regulation of many processes in plant physiology, ranging from tissue growth and fruit ripening to parasitic plant haustorial formation and host invasion. Thus, control of PME activity is critical for enhancing our understanding of plant physiological processes and regulation. Here we report on the identification of epigallocatechin gallate (EGCG), a green tea component, as a natural inhibitor for pectin ...

  4. Inhibition of pectin methyl esterase activity by green tea catechins.

    Science.gov (United States)

    Lewis, Kristin C; Selzer, Tzvia; Shahar, Chen; Udi, Yael; Tworowski, Dmitry; Sagi, Irit

    2008-10-01

    Pectin methyl esterases (PMEs) and their endogenous inhibitors are involved in the regulation of many processes in plant physiology, ranging from tissue growth and fruit ripening to parasitic plant haustorial formation and host invasion. Thus, control of PME activity is critical for enhancing our understanding of plant physiological processes and regulation. Here, we report on the identification of epigallocatechin gallate (EGCG), a green tea component, as a natural inhibitor for pectin methyl esterases. In a gel assay for PME activity, EGCG blocked esterase activity of pure PME as well as PME extracts from citrus and from parasitic plants. Fluorometric tests were used to determine the IC50 for a synthetic substrate. Molecular docking analysis of PME and EGCG suggests close interaction of EGCG with the catalytic cleft of PME. Inhibition of PME by the green tea compound, EGCG, provides the means to study the diverse roles of PMEs in cell wall metabolism and plant development. In addition, this study introduces the use of EGCG as natural product to be used in the food industry and agriculture.

  5. An increase in pectin methyl esterase activity accompanies dormancy breakage and germination of yellow cedar seeds.

    Science.gov (United States)

    Ren, C; Kermode, A R

    2000-09-01

    Pectin methyl esterase (PME) (EC 3.1.1.11) catalyzes the hydrolysis of methylester groups of cell wall pectins. We investigated the role of this enzyme in dormancy termination and germination of yellow cedar (Chamaecyparis nootkatensis [D. Don] Spach) seeds. PME activity was not detected in dormant seeds of yellow cedar but was induced and gradually increased during moist chilling; high activity coincided with dormancy breakage and germination. PME activity was positively correlated to the degree of dormancy breakage of yellow cedar seeds. The enzyme produced in different seed parts and in seeds at different times during moist chilling, germination, and early post-germinative growth consisted of two isoforms, both basic with isoelectric points of 8.7 and 8.9 and the same molecular mass of 62 kD. The pH optimum for the enzyme was between 7.4 and 8.4. In intact yellow cedar seeds, activities of the two basic isoforms of PME that were induced in embryos and in megagametophytes following dormancy breakage were significantly suppressed by abscisic acid. Gibberellic acid had a stimulatory effect on the activities of these isoforms in embryos and megagametophytes of intact seeds at the germinative stage. We hypothesize that PME plays a role in weakening of the megagametophyte, allowing radicle emergence and the completion of germination.

  6. Pectin Methyl Esterase Activity Change in Intermediate Moisture Sun-Dried Figs after Storage

    Directory of Open Access Journals (Sweden)

    Dilek Demirbüker Kavak

    2015-12-01

    Full Text Available Intermediate moisture fruits can be obtained by rehydrating dried fruits. Intermediate moisture fruits are suitable for direct consumption compared to dry fruits and can be directly used in the production of various products such as bakery products, dairy products and candies. Aim of this study is to compare the pectin methyl esterase (PME activity of intermediate moisture figs which causes softening of the texture and to compare their microbial stability after 3 months storage period. For this purpose, dried figs were rehydrated in 30 and 80° C water until they reach 30% moisture content. Rehydrated samples were stored for 3 months at +4°C. Results showed that there was no statistically significant difference between the control samples and the samples rehydrated at 80°C according to the total viable counts. At the end of the storage period, results of residual PME activity in control samples was 24.1 μmol COOH min-1g-1, while it was found 17.4 μmol COOH min-1g-1 in samples rehydrated at 80°C. As a result rehydration conducted at 80°C provided 28% reduction in PME activity compared to the control samples rehydrated at 30°C, although it did not affect the microbial load significantly after storage.

  7. Potato tuber pectin structure is influenced by pectin methyl esterase activity and impacts on cooked potato texture

    OpenAIRE

    Ross, Heather A.; Wright, Kathryn M.; McDougall, Gordon J.; Roberts, Alison G.; Chapman, Sean N.; Morris, Wayne L.; Hancock, Robert D.; Stewart, Derek; Tucker, Gregory A.; James, Euan K.; Taylor, Mark A.

    2010-01-01

    Although cooked potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase activity (PME) as a potential factor impacting on textural properties. In this study, tuber PME isoform and gene expression profiles have been determined in potato germplasm with differing textural properties as assessed using an amended wedge fracture m...

  8. Multiple resistance to pirimiphos-methyl and bifenthrin in Tribolium castaneum involves the activity of lipases, esterases, and laccase2.

    Science.gov (United States)

    Julio, Alison Henrique Ferreira; Gigliolli, Adriana Aparecida Sinópolis; Cardoso, Kátia Aparecida Kern; Drosdoski, Sandro Daniel; Kulza, Rodrigo Amaral; Seixas, Flávio Augusto Vicente; Ruvolo-Takasusuki, Maria Claudia Colla; de Souza, Cristina Giatti Marques; Lapenta, Ana Silvia

    2017-05-01

    Several recent studies have elucidated the molecular mechanisms that confer insecticide resistance on insect pests. However, little is known about multiple resistance in red flour beetle (Tribolium castaneum) at molecular level. The multiple resistance is characterized as resistance to different classes of insecticides that have different target sites, and is mediated by several enzymatic systems. In this study, we investigated the biochemical and molecular mechanisms involved in multiple resistance of T. castaneum to bifenthrin (pyrethroid [Pyr]) and pirimiphos-methyl (organophosphate [Org]). We used artificial selection, biochemical and in silico approaches including structural computational biology. After five generations of artificial selection in the presence of bifenthrin (F5Pyr) or pirimiphos-methyl (F5Org), we found high levels of multiple resistance. The hierarchical enzymatic cluster revealed a pool of esterases (E), lipases (LIPs) and laccase2 (LAC2) potentially contributing to the resistance in different ways throughout development, after one or more generations in the presence of insecticides. The enzyme-insecticide interaction network indicated that E2, E3, LIP3, and LAC2 are enzymes potentially required for multiple resistance phenotype. Kinetic analysis of esterases from F5Pyr and F5Org showed that pirimiphos-methyl and specially bifenthrin promote enzyme inhibition, indicating that esterases mediate resistance by sequestering bifenthrin and pirimiphos-methyl. Our computational data were in accordance with kinetic results, indicating that bifenthrin has higher affinity at the active site of esterase than pirimiphos-methyl. We also report the capability of these insecticides to modify the development in T. castaneum. Our study provide insights into the biochemical mechanisms employed by T. castaneum to acquire multiple resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Potato tuber pectin structure is influenced by pectin methyl esterase activity and impacts on cooked potato texture.

    Science.gov (United States)

    Ross, Heather A; Wright, Kathryn M; McDougall, Gordon J; Roberts, Alison G; Chapman, Sean N; Morris, Wayne L; Hancock, Robert D; Stewart, Derek; Tucker, Gregory A; James, Euan K; Taylor, Mark A

    2011-01-01

    Although cooked potato tuber texture is an important trait that influences consumer preference, a detailed understanding of tuber textural properties at the molecular level is lacking. Previous work has identified tuber pectin methyl esterase activity (PME) as a potential factor impacting on textural properties. In this study, tuber PME isoform and gene expression profiles have been determined in potato germplasm with differing textural properties as assessed using an amended wedge fracture method and a sloughing assay, revealing major differences between the potato types. Differences in pectin structure between potato types with different textural properties were revealed using monoclonal antibodies specific for different pectic epitopes. Chemical analysis of tuber pectin clearly demonstrated that, in tubers containing a higher level of total PME activity, there was a reduced degree of methylation of cell wall pectin and consistently higher peak force and work done values during the fracture of cooked tuber samples, demonstrating the link between PME activity, the degree of methylation of cell wall pectin, and cooked tuber textural properties.

  10. Effect of temperature and high pressure on the activity and mode of action of fungal pectin methyl esterase.

    Science.gov (United States)

    Duvetter, Thomas; Fraeye, Ilse; Sila, Daniel N; Verlent, Isabel; Smout, Chantal; Clynen, Elke; Schoofs, Liliane; Schols, Henk; Hendrickx, Marc; Van Loey, Ann

    2006-01-01

    Pectin was de-esterified with purified recombinant Aspergillus aculeatus pectin methyl esterase (PME) during isothermal-isobaric treatments. By measuring the release of methanol as a function of treatment time, the rate of enzymatic pectin conversion was determined. Elevated temperature and pressure were found to stimulate PME activity. The highest rate of PME-catalyzed pectin de-esterification was obtained when combining pressures in the range 200-300 MPa with temperatures in the range 50-55 degrees C. The mode of pectin de-esterification was investigated by characterizing the pectin reaction products by enzymatic fingerprinting. No significant effect of increasing pressure (300 MPa) and/or temperature (50 degrees C) on the mode of pectin conversion was detected.

  11. Effect of Temperature and High Pressure on the Activity and Mode of Action of Fungal Pectin Methyl Esterase

    NARCIS (Netherlands)

    Duvetter, T.; Fraeye, I.; Sila, D.N.; Verlent, I.; Smout, C.; Clynen, E.; Schoofs, L.; Schols, H.A.; Hendrickx, M.; Loey, van A.

    2006-01-01

    Pectin was de-esterified with purified recombinant Aspergillus aculeatus pectin methyl esterase (PME) during isothermal-isobaric treatments. By measuring the release of methanol as a function of treatment time, the rate of enzymatic pectin conversion was determined. Elevated temperature and pressure

  12. Changes in pectin methyl esterase activity with different packaging materials and stages of fruit harvesting during cold storage of pear cv. Punjab beauty

    OpenAIRE

    Kaur, Kirandeep; Dhillon, W. S.; Mahajan, B. V. C.

    2012-01-01

    Pear cv. Punjab Beauty has become quite popular in Punjab. Excessive softening during cold storage leading to low shelf life is the major factor limiting its wider adoption. Studies were, therefore, conducted to determine the firmness and pectin methyl esterase (PME) activity at 4 harvest dates (2nd, 3rd and 4th week of July, and 1st week of August). Various packaging materials i.e. corrugated fiber board boxes and crates with high and low density polyethylene liners, corrugated fiber board b...

  13. Changes in pectin methyl esterase activity with different packaging materials and stages of fruit harvesting during cold storage of pear cv. Punjab beauty.

    Science.gov (United States)

    Kaur, Kirandeep; Dhillon, W S; Mahajan, B V C

    2014-10-01

    Pear cv. Punjab Beauty has become quite popular in Punjab. Excessive softening during cold storage leading to low shelf life is the major factor limiting its wider adoption. Studies were, therefore, conducted to determine the firmness and pectin methyl esterase (PME) activity at 4 harvest dates (2nd, 3rd and 4th week of July, and 1st week of August). Various packaging materials i.e. corrugated fiber board boxes and crates with high and low density polyethylene liners, corrugated fiber board boxes, crates and wooden boxes were also evaluated for their role in extending the shelf life of fruits. The enzyme activity and fruit firmness was evaluated periodically after 30, 45, 60 and 75 days of storage at 0-1 °C and 90-95 % RH. The firmness of the fruits decreased with the increase in storage intervals but the enzyme activity increased with the storage period up to 60 days and declined thereafter. Ripening-related changes in all the harvests were characterized mainly by an increase in the solubilization of pectin with a concomitant decrease in the degree of firmness. There was a continuous increase in enzyme activity with the advancement in harvesting dates and then fell sharply in the advanced ripening stages. Highest pectin methyl esterase activity was in fruits packed in crates followed by wooden boxes and corrugated fiber board boxes while the lowest was recorded in fruits packed in corrugated fiber board boxes with high density polyethylene liners. Therefore, high density polyethylene lined CFB boxes proved to be most effective in preventing the loss in firmness.

  14. Requirement for Pectin Methyl Esterase and Preference for Fragmented over Native Pectins for Wall-associated Kinase-activated, EDS1/PAD4-dependent Stress Response in Arabidopsis*

    Science.gov (United States)

    Kohorn, Bruce D.; Kohorn, Susan L.; Saba, Nicholas J.; Martinez, Victoriano Meco

    2014-01-01

    The wall-associated kinases (WAKs) have a cytoplasmic protein kinase domain that spans the plasma membrane and binds pectin in the extracellular matrix of plants. WAKs are required for cell expansion during Arabidopsis seedling development but are also an integral part of the response to pathogens and stress that present oligogalacturonides (OGs), which subsequently bind to WAKs and activate a MPK6 (mitogen-activated protein kinase)-dependent pathway. It was unclear how WAKs distinguish native pectin polymers and OGs to activate one or the other of these two pathways. A dominant allele of WAK2 constitutively activates the stress response, and we show here that the effect is dependent upon EDS1 and PAD4, transcriptional activators involved in the pathogen response. Moreover, the WAK2 dominant allele is suppressed by a null allele of a pectin methyl esterase (PME3) whose activity normally leads to cross-linking of pectins in the cell wall. Although OGs activate a transcriptional response in wild type, the response is enhanced in a pme3/pme3 null, consistent with a competition by OG and native polymers for activation of WAKs. This provides a plausible mechanism for WAKs to distinguish an expansion from a stress pathway. PMID:24855660

  15. Requirement for pectin methyl esterase and preference for fragmented over native pectins for wall-associated kinase-activated, EDS1/PAD4-dependent stress response in Arabidopsis.

    Science.gov (United States)

    Kohorn, Bruce D; Kohorn, Susan L; Saba, Nicholas J; Martinez, Victoriano Meco

    2014-07-04

    The wall-associated kinases (WAKs) have a cytoplasmic protein kinase domain that spans the plasma membrane and binds pectin in the extracellular matrix of plants. WAKs are required for cell expansion during Arabidopsis seedling development but are also an integral part of the response to pathogens and stress that present oligogalacturonides (OGs), which subsequently bind to WAKs and activate a MPK6 (mitogen-activated protein kinase)-dependent pathway. It was unclear how WAKs distinguish native pectin polymers and OGs to activate one or the other of these two pathways. A dominant allele of WAK2 constitutively activates the stress response, and we show here that the effect is dependent upon EDS1 and PAD4, transcriptional activators involved in the pathogen response. Moreover, the WAK2 dominant allele is suppressed by a null allele of a pectin methyl esterase (PME3) whose activity normally leads to cross-linking of pectins in the cell wall. Although OGs activate a transcriptional response in wild type, the response is enhanced in a pme3/pme3 null, consistent with a competition by OG and native polymers for activation of WAKs. This provides a plausible mechanism for WAKs to distinguish an expansion from a stress pathway. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. A p-coumaroyl esterase from Rhizoctonia solani with a pronounced chlorogenic acid esterase activity.

    Science.gov (United States)

    Nieter, Annabel; Kelle, Sebastian; Linke, Diana; Berger, Ralf G

    2017-07-25

    Extracellular esterase activity was detected in submerged cultures of Rhizoctonia solani grown in the presence of sugar beet pectin or Tween 80. Putative type B feruloyl esterase (FAE) coding sequences found in the genome data of the basidiomycete were heterologously expressed in Pichia pastoris. Recombinant enzyme production on the 5-L bioreactor scale (Rs pCAE: 3245UL -1 ) exceeded the productivity of the wild type strain by a factor of 800. Based on substrate specificity profiling, the purified recombinant Rs pCAE was classified as a p-coumaroyl esterase (pCAE) with a pronounced chlorogenic acid esterase side activity. The Rs pCAE was also active on methyl cinnamate, caffeate and ferulate and on feruloylated saccharides. The unprecedented substrate profile of Rs pCAE together with the lack of sequence similarity to known FAEs or pCAEs suggested that the Rs pCAE represents a new type of enzyme. Hydroxycinnamic acids were released from agro-industrial side-streams, such as destarched wheat bran (DSWB), sugar beet pectin (SBP) and coffee pulp (CP). Overnight incubation of coffee pulp with the Rs pCAE resulted in the efficient release of p-coumaric (100%), caffeic (100%) and ferulic acid (85%) indicating possible applications for the valorization of food processing wastes and for the enhanced degradation of lignified biomass. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Chromatographic study of highly methoxylated lime pectins deesterified by different pectin methyl-esterases.

    Science.gov (United States)

    Ralet, M C; Bonnin, E; Thibault, J F

    2001-03-25

    The inter-molecular distribution of free carboxyl groups of two highly methoxylated pectins enzymatically deesterified by plant and fungus pectin methyl-esterases were investigated by size-exclusion (SEC) and ion-exchange chromatography (IEC). "Homogeneous" populations with respect to molar mass or charge density were thereby obtained and their chemical composition and physico-chemical properties (transport parameter for monovalent cations and calcium, calcium activity coefficient) were studied. Chemical analysis showed that the composition varies from one SEC fraction to another, the highest molar mass fraction being richer in rhamnose and galactose and exhibiting a slightly higher degree of methylation. Separation of pectins by IEC revealed a quite homogeneous charge density distribution for F58 contrary to P60 which exhibited a large distribution of methoxyl groups. The free carboxyl groups distributions and calcium binding behaviours of SEC and IEC fractions were shown to differ widely for highly methoxylated pectins deesterified by plant and fungus pectin methyl-esterases.

  18. HIGHLY METHYL ESTERIFIED SEEDS is a pectin methyl esterase involved in embryo development.

    Science.gov (United States)

    Levesque-Tremblay, Gabriel; Müller, Kerstin; Mansfield, Shawn D; Haughn, George W

    2015-03-01

    Homogalacturonan pectin domains are synthesized in a highly methyl-esterified form that later can be differentially demethyl esterified by pectin methyl esterase (PME) to strengthen or loosen plant cell walls that contain pectin, including seed coat mucilage, a specialized secondary cell wall of seed coat epidermal cells. As a means to identify the active PMEs in seed coat mucilage, we identified seven PMEs expressed during seed coat development. One of these, HIGHLY METHYL ESTERIFIED SEEDS (HMS), is abundant during mucilage secretion, peaking at 7 d postanthesis in both the seed coat and the embryo. We have determined that this gene is required for normal levels of PME activity and homogalacturonan methyl esterification in the seed. The hms-1 mutant displays altered embryo morphology and mucilage extrusion, both of which are a consequence of defects in embryo development. A significant decrease in the size of cells in the embryo suggests that the changes in embryo morphology are a consequence of lack of cell expansion. Progeny from a cross between hms-1 and the previously characterized PME inhibitor5 overexpression line suggest that HMS acts independently from other cell wall-modifying enzymes in the embryo. We propose that HMS is required for cell wall loosening in the embryo to facilitate cell expansion during the accumulation of storage reserves and that its role in the seed coat is masked by redundancy. © 2015 American Society of Plant Biologists. All Rights Reserved.

  19. The ectopic expression of a pectin methyl esterase inhibitor increases pectin methyl esterification and limits fungal diseases in wheat.

    Science.gov (United States)

    Volpi, Chiara; Janni, Michela; Lionetti, Vincenzo; Bellincampi, Daniela; Favaron, Francesco; D'Ovidio, Renato

    2011-09-01

    Cell wall pectin methyl esterification can influence plant resistance because highly methyl-esterified pectin can be less susceptible to the hydrolysis by pectic enzymes such as fungal endopolygalacturonases (PG). Pectin is secreted into the cell wall in a highly methyl-esterified form and, here, is de-methyl esterified by pectin methyl esterase (PME). The activity of PME is controlled by specific protein inhibitors called PMEI; consequently, an increased inhibition of PME by PMEI might modify the pectin methyl esterification. In order to test the possibility of improving wheat resistance by modifying the methyl esterification of pectin cell wall, we have produced durum wheat transgenic lines expressing the PMEI from Actinidia chinensis (AcPMEI). The expression of AcPMEI endows wheat with a reduced endogenous PME activity, and transgenic lines expressing a high level of the inhibitor showed a significant increase in the degree of methyl esterification. These lines showed a significant reduction of disease symptoms caused by the fungal pathogens Bipolaris sorokiniana or Fusarium graminearum. This increased resistance was related to the impaired ability of these fungal pathogens to grow on methyl-esterified pectin and to a reduced activity of the fungal PG to hydrolyze methyl-esterified pectin. In addition to their importance for wheat improvement, these results highlight the primary role of pectin despite its low content in the wheat cell wall.

  20. Cholesterol esterase activity of human intestinal mucosa

    International Nuclear Information System (INIS)

    Ponz de Leon, M.; Carubbi, F.; Di Donato, P.; Carulli, N.

    1985-01-01

    It has been suggested that cholesterol absorption in humans is dependent on bile acid pool composition and that expansion of the cholic acid pool size is followed by an increase of the absorption values. Similar observations were reported in rats. In the present study, therefore, the authors investigated some general properties of human intestinal cholesterol esterase, with particular emphasis on the effect of bile acids on this enzymatic activity. Twenty-nine segments of small intestine were taken during operations; the enzymatic activity was studied by using mucosal homogenate as a source of enzyme and oleic acid, cholesterol, and 14 C-labeled cholesterol as substrates. The time-activity relationship was linear within the first two hours; optimal pH for esterification ranged between 5 and 6.2. There was little difference between the esterifying activity of the jejunal and ileal mucosa. Esterification of cholesterol was observed with all the investigated fatty acids but was maximal with oleic acid. Bile acids did not affect cholesterol esterase activity when present in the incubation mixture at 0.1 and 1.0 mM; the enzymatic activity, however, was significantly inhibited when bile acids were added at 20 mM. In conclusion, this study has shown that the human intestinal mucosa possesses a cholesterol esterase activity; at variance with the rat, however, the human enzyme does not seem to be stimulated by trihydroxy bile acids

  1. Characterization and distribution of esterase activity in activated sludge

    NARCIS (Netherlands)

    Boczar, BA; Forney, LJ; Begley, WM; Larson, RJ; Federle, TW

    2001-01-01

    The location and activity of esterase enzymes in activated Sludge from three Municipal wastewater treatment plants were characterized using model Substrate, and denaturing and nondenaturing polyacrylamide gel electrophoresis (PAGE) Of particulate, freeze thaw (primarily periplasmic enzymes and those

  2. Pectin methyl esterase inhibits intrusive and symplastic cell growth in developing wood cells of Populus.

    Science.gov (United States)

    Siedlecka, Anna; Wiklund, Susanne; Péronne, Marie-Amélie; Micheli, Fabienne; Lesniewska, Joanna; Sethson, Ingmar; Edlund, Ulf; Richard, Luc; Sundberg, Björn; Mellerowicz, Ewa J

    2008-02-01

    Wood cells, unlike most other cells in plants, grow by a unique combination of intrusive and symplastic growth. Fibers grow in diameter by diffuse symplastic growth, but they elongate solely by intrusive apical growth penetrating the pectin-rich middle lamella that cements neighboring cells together. In contrast, vessel elements grow in diameter by a combination of intrusive and symplastic growth. We demonstrate that an abundant pectin methyl esterase (PME; EC 3.1.1.11) from wood-forming tissues of hybrid aspen (Populus tremula x tremuloides) acts as a negative regulator of both symplastic and intrusive growth of developing wood cells. When PttPME1 expression was up- and down-regulated in transgenic aspen trees, the PME activity in wood-forming tissues was correspondingly altered. PME removes methyl ester groups from homogalacturonan (HG) and transgenic trees had modified HG methylesterification patterns, as demonstrated by two-dimensional nuclear magnetic resonance and immunostaining using PAM1 and LM7 antibodies. In situ distributions of PAM1 and LM7 epitopes revealed changes in pectin methylesterification in transgenic trees that were specifically localized in expanding wood cells. The results show that en block deesterification of HG by PttPME1 inhibits both symplastic growth and intrusive growth. PttPME1 is therefore involved in mechanisms determining fiber width and length in the wood of aspen trees.

  3. Pectin methyl esterases and pectins in normal and hyperhydric shoots of carnation cultured in vitro.

    Science.gov (United States)

    Saher, Shady; Piqueras, Abel; Hellin, Eladio; Olmos, Enrique

    2005-02-01

    Control and hyperhydric micropropagated plantlets from three carnation cultivars have been used to study their pectin composition and the activity of pectin methyl esterases (PMEs; EC 3.1.1.11). Pectins are a highly heterogeneous group of polymers that contribute to cell adhesion, cell wall architecture, and cell wall mechanical strength. Pectins control cell wall porosity and cell wall ionic status and are implicated in intercellular space development. The degree of esterification of pectins is controlled by the activity of cell wall PMEs; their different actions can affect the properties of the cell wall, which have been considered important with respect to controlling the development of hyperhydricity. The total pectins of hyperhydric leaves of the three varieties were significantly reduced in comparison with controls. The pectate fraction was significantly increased in hyperhydric leaves of all varieties while soluble pectins and protopectins were significantly lower. The PME activity of hyperhydric leaves was higher (4-10 times) compared to controls of the three varieties. Isoelectric focusing of PME isozymes revealed the presence of three isoforms; neutral PME activity was the major isozyme in control and hyperhydric leaves of the three varieties, whilst a decrease in the activity of the acidic isoforms was observed in hyperhydric leaves. The different PME activities could regulate some of the structural changes related to hyperhydricity in micropropagated carnation plants.

  4. Esterase activity as a novel parameter of spore germination in Bacillus anthracis

    International Nuclear Information System (INIS)

    Ferencko, Linda; Cote, Mindy A.; Rotman, Boris

    2004-01-01

    Spores of Bacillus anthracis were shown to produce esterase activity about 4 min after exposure to conventional germinants such as combinations of amino acids and purine ribosides. Neither amino acids nor ribosides alone induce germination and esterase activity. Expression of esterase activity was chloramphenicol resistant, and correlated with loss of spore refractivity, a traditional parameter of early germination. Based on these observations, we hypothesized that esterase activity could be used as a novel parameter for quantifying early events during spore germination. To test this hypothesis, we measured expression of esterase activity under a variety of germinating conditions. Using diacetyl fluorescein as fluorogenic substrate of esterases, we demonstrated that esterase activity was invariably induced whenever spores were triggered by known germinants. Moreover, D-alanine, an inhibitor of L-alanine-mediated germination, was found to significantly inhibit expression of esterase activity. In terms of molecular mechanisms, esterase expression could represent activation of proteases at the onset of spore germination

  5. High-pressure processing of apple juice: kinetics of pectin methyl esterase inactivation.

    Science.gov (United States)

    Riahi, Esmaeil; Ramaswamy, Hosahalli S

    2003-01-01

    High-pressure (HP) inactivation kinetics of pectin methyl esterase (PME) in apple juice were evaluated. Commercial PME was dispensed in clarified apple juice, sealed in dual peel sterilizable plastic bags, and subjected to different high-pressure processing conditions (200-400 MPa, 0-180 min). Residual enzyme activity was determined by a titration method estimating the rate of free carboxyl group released by the enzyme acting on pectin substrate at pH 7.5 (30 degrees C). The effects of pressure level and pressure holding time on enzyme inactivation were significant (p < 0.05). PME from the microbial source was found to be more resistant (p < 0.05) to pressure inactivation than PME from the orange peel. Almost a full decimal reduction in the activity of commercial PME was achieved by HP treatment at 400 MPa for 25 min. Inactivation kinetics were evaluated on the basis of a dual effect model involving a pressure pulse effect and a first-order rate model, and the pressure sensitivity of rate constants was modeled by using the z-value concept.

  6. Intron retention regulates the expression of pectin methyl esterase inhibitor (Pmei) genes during wheat growth and development.

    Science.gov (United States)

    Rocchi, V; Janni, M; Bellincampi, D; Giardina, T; D'Ovidio, R

    2012-03-01

    Pectin is an important component of the plant cell wall and its remodelling occurs during normal plant growth or following stress responses. Pectin is secreted into the cell wall in a highly methyl-esterified form and subsequently de-methyl-esterified by pectin methyl esterase (PME), whose activity is controlled by the pectin methyl esterase inhibitor protein (PMEI). Cereal cell wall contains a low amount of pectin; nonetheless the level and pattern of pectin methyl esterification play a primary role during development or pathogen infection. Since few data are available on the role of PMEI in plant development and defence of cereal species, we isolated and characterised three Pmei genes (Tdpmei2.1, Tdpmei2.2 and Tdpmei3) and their encoded products in wheat. Sequence comparisons showed a low level of intra- and inter-specific sequence conservation of PMEIs. Tdpmei2.1 and Tdpmei2.2 share 94% identity at protein level, but only 20% identity with the product of Tdpmei3. All three Tdpmei genes code for functional inhibitors of plant PMEs and do not inhibit microbial PMEs or a plant invertase. RT-PCR analyses demonstrated, for the first time to our knowledge, that Pmei genes are regulated by intron retention. Processed and unprocessed transcripts of Tdpmei2.1 and Tdpmei2.2 accumulated in several organs, but anthers contained only mature transcripts. Tdpmei3 lacks introns and its transcript accumulated mainly in stem internodes. These findings suggest that products encoded by these Tdpmei genes control organ- or tissue-specific activity of specific PME isoforms in wheat. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Purification and general properties of pectin methyl esterase from Curvularia inaequalis NRRL 13884 in solid state culture using orange peels as an inducer.

    Science.gov (United States)

    Afifi, A F; Fawzi, E M; Foaad, M A

    2002-01-01

    Pectin methyl esterase (PME) [E.C.3. 1.1.11] production by Curvularia inaequalis (Shear) Boedijn NRRL 13884 was investigated using solid-state culture. The highest level of extracellular pectin methyl esterase was detected with orange peels as an inducing substrate and as a sole carbon source. The enzyme was partially purified using Sephadex G-100 and DEAE-Cellulose column chromatography. It was purified about 40 fold with optimum activity at pH 4.4 and 45 degrees C. The enzyme was activated by Co++, Mg++, Na+, whereas it was slightly activated in the presence of Cu++, K+, Mn++, Zn++. On the other hand Ag++, Ca++ and Hg++ inhibited the activity of the enzyme. The Km was calculated to be 0.52 mM.

  8. Pectin methyl esterase and natural microflora of fresh mixed orange and carrot juice treated with pulsed electric fields.

    Science.gov (United States)

    Rodrigo, D; Barbosa-Cánovas, G V; Martínez, A; Rodrigo, M

    2003-12-01

    The effects of pulsed electric fields (PEFs) on pectin methyl esterase (PME), molds and yeast, and total flora in fresh (nonpasteurized) mixed orange and carrot juice were studied. The PEF effect was more extensive when juices with high levels of initial PME activity were subjected to treatment and when PEF treatment (at 25 kV/cm for 340 micros) was combined with a moderate temperature (63 degrees C), with the maximum level of PME inactivation being 81.4%. These conditions produced 3.7 decimal reductions in molds and yeast and 2.4 decimal reductions in total flora. Experimental inactivation data for PME, molds and yeast, and total flora were fitted to Bigelow, Hülsheger, and Weibull inactivation models by nonlinear regression. The best fit (lowest mean square error) was obtained with the Weibull model.

  9. Isolation and Expression analysis of OsPME1, encoding for a putative Pectin Methyl Esterase from Oryza sativa (subsp. indica).

    Science.gov (United States)

    Kanneganti, Vydehi; Gupta, Aditya Kumar

    2009-04-01

    Pectin Methyl Esterases (PMEs) play an essential role during plant development by affecting the mechanical properties of the plant cell walls. Recent studies indicated that PMEs play important role in pollen tube development. In this study, we isolated a 1.3 kb cDNA clone from rice panicle cDNA library. It contained a 1038 bp of open reading frame (ORF) encoding for a putative pectin methyl esterase of 345 aminoacids with a 20 aminoacid signal peptide and was hence designated as OsPME1 (Oryza sativaPectin Methyl Esterase 1). It contained the structural arrangement GXYXE and GXXDFIF, found in the active groups of all PMEs. OsPME1 gene product shared varying identities, ranging from 52 % to 33 % with PMEs from other plant species belonging to Brassicaceae, Fabaceae, Amaranthaceae and Funariaceae. Southern blot analysis indicated that PME1 exists as a single copy in the rice genome. Expression pattern analysis revealed that OsPME1 is expressed only in pollen grains, during the later stages of their development and was also regulated by various abiotic stress treatments and phytohormones. Functional characterization of this pollen specific PME from rice would enable us to understand its role in pollen development.

  10. Esterase activity able to hydrolyze dietary antioxidant hydroxycinnamates is distributed along the intestine of mammals

    DEFF Research Database (Denmark)

    Andreasen, Mette Findal; Kroon, P A; Williamson, G

    2001-01-01

    and may contribute to the beneficial effects derived from consumption of cereal bran. However, these compounds are ester linked to the main polymers in the plant cell wall and cannot be absorbed in this complex form. The present work shows that esterases with activity toward esters of the major dietary...... hydroxycinnamates are distributed throughout the intestinal tract of mammals. In rats, the cinnamoyl esterase activity in the small intestine is derived mainly from the mucosa, whereas in the large intestine the esterase activity was found predominantly in the luminal microflora. Mucosa cell-free extracts obtained...... from human duodenum, jejunum, and ileum efficiently hydrolyzed various hydroxycinnamoyl esters, providing the first evidence of human cinnamoyl esterase(s). This study first demonstrates the release by human colonic esterase(s) (mostly of microbial origin) of sinapic acid and p-coumaric acid from rye...

  11. Effects of temperature, ultraviolet radiation and pectin methyl esterase on aerobic methane release from plant material.

    Science.gov (United States)

    Bruhn, D; Mikkelsen, T N; Obro, J; Willats, W G T; Ambus, P

    2009-11-01

    This study examines the effects of different irradiance types on aerobic methane (CH(4)) efflux rates from terrestrial plant material. Furthermore, the role of the enzyme pectin methyl esterase (PME) on CH(4) efflux potential was also examined. Different types of plant tissue and purified pectin were incubated in glass vials with different combinations of irradiation and/or temperature. Purified dry pectin was incubated in solution, and with or without PME. Before and after incubation, the concentration of CH(4) was measured with a gas chromatograph. Rates of CH(4) emission were found to depend exponentially on temperature and linearly on UV-B irradiance. UV-B had a greater stimulating effect than UV-A, while visible light had no effect on emission rates. PME was found to substantially reduce the potential for aerobic CH(4) emissions upon demethylation of pectin.

  12. Biochemical and Structural Analyses of Two Cryptic Esterases in Bacteroides intestinalis and their Synergistic Activities with Cognate Xylanases.

    Science.gov (United States)

    Wefers, Daniel; Cavalcante, Janaina J V; Schendel, Rachel R; Deveryshetty, Jaigeeth; Wang, Kui; Wawrzak, Zdzislaw; Mackie, Roderick I; Koropatkin, Nicole M; Cann, Isaac

    2017-08-04

    Arabinoxylans are constituents of the human diet. Although not utilizable by the human host, they can be fermented by colonic bacteria. The arabinoxylan backbone is decorated with arabinose side chains that may be substituted with ferulic acid, thus limiting depolymerization to fermentable sugars. We investigated the polypeptides encoded by two genes upregulated during growth of the colonic bacterium Bacteroides intestinalis on wheat arabinoxylan. The recombinant proteins, designated BiFae1A and BiFae1B, were functionally assigned esterase activities. Both enzymes were active on acetylated substrates, although each showed a higher ferulic acid esterase activity on methyl-ferulate. BiFae1A showed a catalytic efficiency of 12mM s -1 on para-nitrophenyl-acetate, and on methyl-ferulate, the value was 27 times higher. BiFae1B showed low catalytic efficiencies for both substrates. Furthermore, the two enzymes released ferulic acid from various structural elements, and NMR spectroscopy indicated complete de-esterification of arabinoxylan oligosaccharides from wheat bran. BiFae1A is a tetramer based on the crystal structure, whereas BiFae1B is a dimer in solution based on size exclusion chromatography. The structure of BiFae1A was solved to 1.98Å resolution, and two tetramers were observed in the asymmetric unit. A flexible loop that may act as a hinge over the active site and likely coordinates critical interactions with the substrate was prominent in BiFae1A. Sequence alignments of the esterase domains in BiFae1B with the feruloyl esterase from Clostridium thermocellum suggest that both domains lack the flexible hinge in BiFae1A, an observation that may partly provide a molecular basis for the differences in activities in the two esterases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (Fragaria vesca).

    Science.gov (United States)

    Osorio, Sonia; Castillejo, Cristina; Quesada, Miguel A; Medina-Escobar, Nieves; Brownsey, Geoff J; Suau, Rafael; Heredia, Antonio; Botella, Miguel A; Valpuesta, Victoriano

    2008-04-01

    In addition to the role of the cell wall as a physical barrier against pathogens, some of its constituents, such as pectin-derived oligogalacturonides (OGA), are essential components for elicitation of defence responses. To investigate how modifications of pectin alter defence responses, we expressed the fruit-specific Fragaria x ananassa pectin methyl esterase FaPE1 in the wild strawberry Fragaria vesca. Pectin from transgenic ripe fruits differed from the wild-type with regard to the degree and pattern of methyl esterification, as well as the average size of pectin polymers. Purified oligogalacturonides from the transgenic fruits showed a reduced degree of esterification compared to oligogalacturonides from wild-type fruits. This reduced esterification is necessary to elicit defence responses in strawberry. The transgenic F. vesca lines had constitutively activated pathogen defence responses, resulting in higher resistance to the necrotropic fungus Botrytis cinerea. Further studies in F. vesca and Nicotiana benthamiana leaves showed that the elicitation capacity of the oligogalacturonides is more specific than previously envisaged.

  14. A comparison between activities for non-specific esterases and esterproteases

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1988-01-01

    Electrophoretic separation of non-specific esterases and esterproteases from kidney, lung, and liver have been carried out in polyacrylamide gels. By use of zone electrophoresis, isoelectric focusing, and 2-dimensional electrophoresis it was found that most of the esterprotease bands had the same...... localization in the gels as non-specific esterase bands. A number of esterase bands showed no activity towards the esterprotease substrates and a single kidney band possessed esterprotease activity only. Isozymes of the ES-6 and ES-9 zones showed sex dependent esterprotease reactions. In sections esterase...

  15. Identification of a Marine Bacillus Strain C5 and Parathion-Methyl Degradation Characteristics of the Extracellular Esterase B1

    Directory of Open Access Journals (Sweden)

    Jianhua Hao

    2014-01-01

    Full Text Available A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value.

  16. Alicyclobacillus acidocaldarius Thermophilic Esterase EST2's Activity in Milk and Cheese Models

    NARCIS (Netherlands)

    Mandrich, L.; Manco, M.; Rossie, M.; Floris, E.; Jansen-van den Bosch, T.; Smit, G.; Wouters, J.A.

    2006-01-01

    The aim of this work was to investigate the behavior of thermophilic esterase EST2 from Alicyclobacillus acidocaldarius in milk and cheese models. The pure enzyme was used to compare the EST2 hydrolytic activity to the activity of endogenous esterase EstA from Lactococcus lactis. The results

  17. Effects of high hydrostatic pressure and temperature increase on Escherichia coli spp. and pectin methyl esterase inactivation in orange juice.

    Science.gov (United States)

    Torres, E F; González-M, G; Klotz, B; Rodrigo, D

    2016-03-01

    The aim of this study was to evaluate the effect of high hydrostatic pressure treatment combined with moderate processing temperatures (25 ℃-50 ℃) on the inactivation of Escherichia coli O157: H7 (ATCC 700728), E. coli K12 (ATCC 23716), and pectin methyl esterase in orange juice, using pressures of 250 to 500 MPa with times ranging between 1 and 30 min. Loss of viability of E. coli O157:H7 increased significantly as pressure and treatment time increased, achieving a 6.5 log cycle reduction at 400 MPa for 3 min at 25 ℃ of treatment. With regard to the inactivation of pectin methyl esterase, the greatest reduction obtained was 90.05 ± 0.01% at 50 ℃ and 500 MPa of pressure for 15 min; therefore, the pectin methyl esterase enzyme was highly resistant to the treatments by high hydrostatic pressure. The results obtained in this study showed a synergistic effect between the high pressure and moderate temperatures in inactivating E. coli cells. © The Author(s) 2016.

  18. Plasma B-esterase activities in European raptors.

    Science.gov (United States)

    Roy, Claudie; Grolleau, Gérard; Chamoulaud, Serge; Rivière, Jean-Louis

    2005-01-01

    B-esterases are serine hydrolases composed of cholinesterases, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and carboxylesterase (CbE). These esterases, found in blood plasma, are inhibited by organophosphorus (OP) and carbamate (CB) insecticides and can be used as nondestructive biomarkers of exposure to anticholinesterase insecticides. Furthermore, B-esterases are involved in detoxification of these insecticides. In order to establish the level of these enzymes and to have reference values for their normal activities, total plasma cholinesterase (ChE), AChE and BChE activities, and plasma CbE activity were determined in 729 European raptors representing 20 species, four families, and two orders. The diurnal families of the Falconiforme order were represented by Accipitridae and Falconidae and the nocturnal families of the Strigiforme order by Tytonidae and Strigidae. Intraspecies differences in cholinesterase activities according to sex and/or age were investigated in buzzards (Buteo buteo), sparrowhawks (Accipiter nisus), kestrels (Falco tinnunculus), barn owls (Tyto alba), and tawny owls (Strix aluco). Sex-related differences affecting ChE and AChE activities were observed in young kestrels (2-3-mo-old) and age-related differences in kestrels (ChE and AChE), sparrowhawks (AChE), and tawny owls (ChE, AChE, and BChE). The interspecies analysis yielded a negative correlation between ChE activity and body mass taking into account the relative contribution of AChE and BChE to ChE activity, with the exception of the honey buzzard (Pernis apivorus). The lowest ChE activities were found in the two largest species, Bonelli's eagle (Hieraaetus fasciatus) and Egyptian vulture (Neophron percnopterus) belonging to the Accipitridae family. The highest ChE activities were found in the relatively small species belonging to the Tytonidae and Strigidae families and in honey buzzard of the Accipitridae family. Species of the Accipitridae, Tytonidae, and

  19. A new microplate screening method for the simultaneous activity quantification of feruloyl esterases, tannases, and chlorogenate esterases.

    Science.gov (United States)

    Ramírez, L; Arrizon, J; Sandoval, G; Cardador, A; Bello-Mendoza, R; Lappe, P; Mateos-Díaz, J C

    2008-12-01

    Feruloyl, chlorogenate esterases, and tannases are enzymes useful in phenolic modifications of pharmaceutical relevance as protectors against several degenerative human diseases. Therefore, there is a growing interest in discovering new sources of these enzymes. However, traditional methods for their activity measurements are time-consuming and poorly adapted for high-throughput screening. In this study, a successful new microplate high-throughput screening method for the simultaneous quantification of all mentioned activities is demonstrated. This method allows the detection of activities as low as 1.7 mU ml(-1). Furthermore, reaction rates increased proportionally with the amount of enzyme added, and no interferences with the other commercial hydrolases tested were found. The utility of the method was demonstrated after simultaneously screening feruloyl, chlorogenate esterase, and tannase activities in solid state fermentation extracts obtained during the kinetics of production of 20 fungal strains. Among these, seven strains were positive for at least one of the esterase activities tested. This result shows the potential for the rapid routine screening assays for multiple samples of moderate low to high enzymatic levels.

  20. Expression of a Petunia inflata pectin methyl esterase in Solanum tuberosum L. enhances stem elongation and modifies cation distribution.

    Science.gov (United States)

    Pilling, J; Willmitzer, L; Fisahn, J

    2000-02-01

    Transgenic potato (Solanum tuberosum L.) plants were constructed with a Petunia inflata-derived cDNA encoding a pectin methyl esterase (PME; EC 3.1.1.11) in sense orientation under the control of the cauliflower mosaic virus 35S promoter. The PME activity was elevated in leaves and tubers of the transgenic lines but slightly reduced in apical segments of stems from mature plants. Stem segments from the base of juvenile PME-overexpressing plants did not differ in PME activity from the control, whereas in apical parts PME was less active than in the wild-type. During the early stages of development stems of these transgenic plants elongated more rapidly than those of the wild-type. Further evidence that overexpression of a plant-derived PME has an impact on plant development is based on modifications of tuber yield, which was reduced in the transgenic lines. Cell walls from transgenic tubers showed significant differences in their cation-binding properties in comparison with the wild-type. In particular, cell walls displayed increased affinity for sodium and calcium, while potassium binding was constant. Furthermore, the total ion content of transgenic potatoes was modified. Indications of PME-mediated differences in the distribution of ions in transgenic plants were also obtained by monitoring relaxations of the membrane potential of roots subsequent to changes in the ionic composition of the bathing solution. However, no effects on the chemical structure of pectin from tuber cell walls could be detected.

  1. A Lactobacillus plantarum Esterase Active on a Broad Range of Phenolic Esters

    Science.gov (United States)

    Esteban-Torres, María; Landete, José María; Reverón, Inés; Santamaría, Laura; de las Rivas, Blanca

    2015-01-01

    Lactobacillus plantarum is the lactic acid bacterial species most frequently found in the fermentation of food products of plant origin on which phenolic compounds are abundant. L. plantarum strains showed great flexibility in their ability to adapt to different environments and growth substrates. Of 28 L. plantarum strains analyzed, only cultures from 7 strains were able to hydrolyze hydroxycinnamic esters, such as methyl ferulate or methyl caffeate. As revealed by PCR, only these seven strains possessed the est_1092 gene. When the est_1092 gene was introduced into L. plantarum WCFS1 or L. lactis MG1363, their cultures acquired the ability to degrade hydroxycinnamic esters. These results support the suggestion that Est_1092 is the enzyme responsible for the degradation of hydroxycinnamic esters on the L. plantarum strains analyzed. The Est_1092 protein was recombinantly produced and biochemically characterized. Surprisingly, Est_1092 was able to hydrolyze not only hydroxycinnamic esters, since all the phenolic esters assayed were hydrolyzed. Quantitative PCR experiments revealed that the expression of est_1092 was induced in the presence of methyl ferulate, an hydroxycinnamic ester, but was inhibited on methyl gallate, an hydroxybenzoic ester. As Est_1092 is an enzyme active on a broad range of phenolic esters, simultaneously possessing feruloyl esterase and tannase activities, its presence on some L. plantarum strains provides them with additional advantages to survive and grow on plant environments. PMID:25746986

  2. A Lactobacillus plantarum esterase active on a broad range of phenolic esters.

    Science.gov (United States)

    Esteban-Torres, María; Landete, José María; Reverón, Inés; Santamaría, Laura; de las Rivas, Blanca; Muñoz, Rosario

    2015-05-01

    Lactobacillus plantarum is the lactic acid bacterial species most frequently found in the fermentation of food products of plant origin on which phenolic compounds are abundant. L. plantarum strains showed great flexibility in their ability to adapt to different environments and growth substrates. Of 28 L. plantarum strains analyzed, only cultures from 7 strains were able to hydrolyze hydroxycinnamic esters, such as methyl ferulate or methyl caffeate. As revealed by PCR, only these seven strains possessed the est_1092 gene. When the est_1092 gene was introduced into L. plantarum WCFS1 or L. lactis MG1363, their cultures acquired the ability to degrade hydroxycinnamic esters. These results support the suggestion that Est_1092 is the enzyme responsible for the degradation of hydroxycinnamic esters on the L. plantarum strains analyzed. The Est_1092 protein was recombinantly produced and biochemically characterized. Surprisingly, Est_1092 was able to hydrolyze not only hydroxycinnamic esters, since all the phenolic esters assayed were hydrolyzed. Quantitative PCR experiments revealed that the expression of est_1092 was induced in the presence of methyl ferulate, an hydroxycinnamic ester, but was inhibited on methyl gallate, an hydroxybenzoic ester. As Est_1092 is an enzyme active on a broad range of phenolic esters, simultaneously possessing feruloyl esterase and tannase activities, its presence on some L. plantarum strains provides them with additional advantages to survive and grow on plant environments. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  3. Studies on the oxidizing system in Holt's medium for histochemical demonstration of esterase activity

    DEFF Research Database (Denmark)

    Kirkeby, S; Blecher, S R

    1978-01-01

    Esterase activity in guinea-pig thyroid and mouse epididymis epithelial cells has been studied using 5-bromoindoxyl acetate as substrate. The pattern of esterase activity in the thyroid of the guinea-pig is constant, irrespective of whether ferri-ferrocyanide (FFC) or certain copper compounds...... cells contain an esterase activity which is not inhibited by conventional SH blocking agents, nor by high concentrations of FFC. From these results it appears that the mode of action of FFC in Holt's medium is as follows. At low concentrations FFC appears to act primarily as a catalytic agent...... in oxidation of indoxyl to indigoid. At high concentration FFC acts as an inhibitor of guinea-pig thyroid esterase, by oxidation of SH groups in the active centre. The esterase of mouse epididymis cell type EH 1 is not subject to this inhibition by FFC, presumably because it does not contain accessible SH...

  4. A Novel Cold Active Esterase from a Deep Sea Sponge Stelletta normani Metagenomic Library

    Directory of Open Access Journals (Sweden)

    Erik Borchert

    2017-09-01

    Full Text Available Esterases catalyze the hydrolysis of ester bonds in fatty acid esters with short-chain acyl groups. Due to the widespread applications of lipolytic enzymes in various industrial applications, there continues to be an interest in novel esterases with unique properties. Marine ecosystems have long been acknowledged as a significant reservoir of microbial biodiversity and in particular of bacterial enzymes with desirable characteristics for industrial use, such as for example cold adaptation and activity in the alkaline pH range. We employed a functional metagenomic approach to exploit the enzymatic potential of one particular marine ecosystem, namely the microbiome of the deep sea sponge Stelletta normani. Screening of a metagenomics library from this sponge resulted in the identification of a number of lipolytic active clones. One of these encoded a highly, cold-active esterase 7N9, and the recombinant esterase was subsequently heterologously expressed in Escherichia coli. The esterase was classified as a type IV lipolytic enzyme, belonging to the GDSAG subfamily of hormone sensitive lipases. Furthermore, the recombinant 7N9 esterase was biochemically characterized and was found to be most active at alkaline pH (8.0 and displays salt tolerance over a wide range of concentrations. In silico docking studies confirmed the enzyme's activity toward short-chain fatty acids while also highlighting the specificity toward certain inhibitors. Furthermore, structural differences to a closely related mesophilic E40 esterase isolated from a marine sediment metagenomics library are discussed.

  5. Modulation of the degree and pattern of methyl-esterification of pectic homogalacturonan in plant cell walls. Implications for pectin methyl esterase action, matrix properties, and cell adhesion.

    Science.gov (United States)

    Willats, W G; Orfila, C; Limberg, G; Buchholt, H C; van Alebeek, G J; Voragen, A G; Marcus, S E; Christensen, T M; Mikkelsen, J D; Murray, B S; Knox, J P

    2001-06-01

    Homogalacturonan (HG) is a multifunctional pectic polysaccharide of the primary cell wall matrix of all land plants. HG is thought to be deposited in cell walls in a highly methyl-esterified form but can be subsequently de-esterified by wall-based pectin methyl esterases (PMEs) that have the capacity to remove methyl ester groups from HG. Plant PMEs typically occur in multigene families/isoforms, but the precise details of the functions of PMEs are far from clear. Most are thought to act in a processive or blockwise fashion resulting in domains of contiguous de-esterified galacturonic acid residues. Such de-esterified blocks of HG can be cross-linked by calcium resulting in gel formation and can contribute to intercellular adhesion. We demonstrate that, in addition to blockwise de-esterification, HG with a non-blockwise distribution of methyl esters is also an abundant feature of HG in primary plant cell walls. A partially methyl-esterified epitope of HG that is generated in greatest abundance by non-blockwise de-esterification is spatially regulated within the cell wall matrix and occurs at points of cell separation at intercellular spaces in parenchymatous tissues of pea and other angiosperms. Analysis of the properties of calcium-mediated gels formed from pectins containing HG domains with differing degrees and patterns of methyl-esterification indicated that HG with a non-blockwise pattern of methyl ester group distribution is likely to contribute distinct mechanical and porosity properties to the cell wall matrix. These findings have important implications for our understanding of both the action of pectin methyl esterases on matrix properties and mechanisms of intercellular adhesion and its loss in plants.

  6. A bacterial cocaine esterase protects against cocaine-induced epileptogenic activity and lethality.

    Science.gov (United States)

    Jutkiewicz, Emily M; Baladi, Michelle G; Cooper, Ziva D; Narasimhan, Diwahar; Sunahara, Roger K; Woods, James H

    2009-09-01

    Cocaine toxicity results in cardiovascular complications, seizures, and death and accounts for approximately 20% of drug-related emergency department visits every year. Presently, there are no treatments to eliminate the toxic effects of cocaine. The present study hypothesizes that a bacterial cocaine esterase with high catalytic efficiency would provide rapid and robust protection from cocaine-induced convulsions, epileptogenic activity, and lethality. Cocaine-induced paroxysmal activity and convulsions were evaluated in rats surgically implanted with radiotelemetry devices (N=6 per treatment group). Cocaine esterase was administered 1 minute after a lethal dose of cocaine or after cocaine-induced convulsions to determine the ability of the enzyme to prevent or reverse, respectively, the effects of cocaine. The cocaine esterase prevented all cocaine-induced electroencephalographic changes and lethality. This effect was specific for cocaine because the esterase did not prevent convulsions and death induced by a cocaine analog, (-)-2beta-carbomethoxy-3beta-phenyltropane. The esterase prevented lethality even after cocaine-induced convulsions occurred. In contrast, the short-acting benzodiazepine, midazolam, prevented cocaine-induced convulsions but not the lethal effects of cocaine. The data showed that cocaine esterase successfully degraded circulating cocaine to prevent lethality and that cocaine-induced convulsions alone are not responsible for the lethal effects of cocaine in this model. Therefore, further investigation into the use of cocaine esterase for treating cocaine overdose and its toxic effects is warranted.

  7. Glucuronoyl esterase--novel carbohydrate esterase produced by Schizophyllum commune.

    Science.gov (United States)

    Spániková, Silvia; Biely, Peter

    2006-08-21

    The cellulolytic system of the wood-rotting fungus Schizophyllum commune contains an esterase that hydrolyzes methyl ester of 4-O-methyl-d-glucuronic acid. The enzyme, called glucuronoyl esterase, was purified to electrophoretic homogeneity from a cellulose-spent culture fluid. Its substrate specificity was examined on a number of substrates of other carbohydrate esterases such as acetylxylan esterase, feruloyl esterase and pectin methylesterase. The glucuronoyl esterase attacks exclusively the esters of MeGlcA. The methyl ester of free or glycosidically linked MeGlcA was not hydrolysed by other carbohydrate esterases. The results suggest that we have discovered a new type of carbohydrate esterase that might be involved in disruption of ester linkages connecting hemicellulose and lignin in plant cell walls.

  8. Acetylcholine esterase activity in mild cognitive impairment and Alzheimer's disease

    International Nuclear Information System (INIS)

    Herholz, Karl

    2008-01-01

    Impairment of cholinergic neurotransmission is a well-established fact in Alzheimer's disease (AD), but there is controversy about its relevance at the early stages of the disease and in mild cognitive impairment (MCI). In vivo positron emission tomography imaging of cortical acetylcholine esterase (AChE) activity as a marker of cholinergic innervation that is expressed by cholinergic axons and cholinoceptive neurons has demonstrated a reduction of this enzyme activity in manifest AD. The technique is also useful to measure the inhibition of cerebral AChE induced by cholinesterase inhibitors for treatment of dementia symptoms. A reduction of cortical AchE activity was found consistently in all studies of AD and in few cases of MCI who later concerted to AD. The in vivo findings in MCI and very mild AD are still preliminary, and studies seem to suggest that cholinergic innervation and AChE as the main degrading enzyme are both reduced, which might result in partial compensation of their effect. (orig.)

  9. A cold active (2R,3R)-(-)-di-O-benzoyl-tartrate hydrolyzing esterase from Rhodotorula mucilaginosa.

    Science.gov (United States)

    Zimmer, Christian; Platz, Tanja; Cadez, Neza; Giffhorn, Friedrich; Kohring, Gert-Wieland

    2006-11-01

    In a screening procedure a pink-colored yeast was isolated from enrichment cultures with (2R,3R)-(-)-di-O-benzoyl-tartrate (benzoyl-tartrate) as the sole carbon source. The organism saar1 was identified by morphological, physiological, and 18S ribosomal DNA/internal transcribed spacer analysis as Rhodotorula mucilaginosa, a basidiomycetous yeast. During growth the yeast hydrolyzed the dibenzoyl ester stoichiometrically to the monoester using the separated benzoate as the growth substrate, before the monoester was further cleaved into benzoate and tartrate, which were both metabolized. The corresponding benzoyl esterase was purified from the culture supernatant and characterized as a monomeric glycosylated 86-kDa protein with an optimum pH of 7.5 and an optimum temperature of 45 degrees C. At 0 degrees C the esterase still exhibited 20% of the corresponding activity at 30 degrees C, which correlates it to psychrophilic enzymes. The esterase could hydrolyze short chain p-nitrophenyl-alkyl esters and several benzoyl esters like benzoyl-methyl ester, ethylene-glycol-dibenzoyl ester, phenyl-benzoyl ester, cocaine, and 1,5-anhydro-D: -fructose-tribenzoyl ester. However feruloyl-ethyl ester was not hydrolyzed. The activity characteristics let the enzyme appear as a promising tool for synthesis of benzoylated compounds for pharmaceutical, cosmetic, or fine chemical applications, even at low temperatures.

  10. Isolation and Expression analysis of OsPME1, encoding for a putative Pectin Methyl Esterase from Oryza sativa (subsp. indica)

    OpenAIRE

    Kanneganti, Vydehi; Gupta, Aditya Kumar

    2009-01-01

    Pectin Methyl Esterases (PMEs) play an essential role during plant development by affecting the mechanical properties of the plant cell walls. Recent studies indicated that PMEs play important role in pollen tube development. In this study, we isolated a 1.3 kb cDNA clone from rice panicle cDNA library. It contained a 1038 bp of open reading frame (ORF) encoding for a putative pectin methyl esterase of 345 aminoacids with a 20 aminoacid signal peptide and was hence designated as OsPME1 (Oryza...

  11. Chaperone-like activities of α-synuclein: α-Synuclein assists enzyme activities of esterases

    International Nuclear Information System (INIS)

    Ahn, Misun; Kim, SeungBum; Kang, Mira; Ryu, Yeonwoo; Doohun Kim, T.

    2006-01-01

    α-Synuclein, a major constituent of Lewy bodies (LBs), has been implicated to play a critical role in the pathogenesis of Parkinson's disease (PD), although the physiological function of α-synuclein has not yet been known. Here we have shown that α-synuclein, which has no well-defined secondary or tertiary structure, can protect the enzyme activity of microbial esterases against stress conditions such as heat, pH, and organic solvents. In particular, the flexibility of α-synuclein and its C-terminal region seems to be important for complex formation, but the structural integrity of the C-terminal region may not be required for stabilization of enzyme activity. In addition, atomic force microscopy (AFM) and in vivo enzyme assays showed highly specific interactions of esterases with α-synuclein. Our results indicate that α-synuclein not only protects the enzyme activity of microbial esterases in vitro, but also can stabilize the active conformation of microbial esterases in vivo

  12. Serine esterase and hemolytic activity in human cloned cytotoxic T lymphocytes

    OpenAIRE

    1988-01-01

    Target cell lysis by most murine cytotoxic T lymphocytes appears to be mediated by a complement (C9)-like protein called perforin, contained in high-density cytoplasmic granules. These granules also contain high levels of serine esterase activity, which may also play a role in cytolysis. Analysis of 17 cloned human cytotoxic T lymphocytes revealed the presence of serine esterase that is very similar to its murine counterpart in substrate and inhibitor specificities, pH optimum, and molecular ...

  13. The search of the target of promotion: Phenylbenzoate esterase activities in hen peripheral nerve

    International Nuclear Information System (INIS)

    Moretto, A.; Nicolli, A.; Lotti, M.

    2007-01-01

    Certain esterase inhibitors, such as carbamates, phosphinates and sulfonyl halides, do not cause neuropathy as some organophosphates, but they may exacerbate chemical or traumatic insults to axons. This phenomenon is called promotion of axonopathies. Given the biochemical and toxicological characteristics of these compounds, the hypothesis was made that the target of promotion is a phenyl valerate (PV) esterase similar to neuropathy target esterase (NTE), the target of organophosphate induced delayed polyneuropathy. However, attempts to identify a PV esterase in hen peripheral nerve have been, so far, unsuccessful. We tested several esters, other than PV, as substrates of esterases from crude homogenate of the hen peripheral nerve. The ideal substrate should be poorly hydrolysed by NTE but extensively by enzyme(s) that are insensitive to non-promoters, such as mipafox, and sensitive to promoters, such as phenyl methane sulfonyl fluoride (PMSF). When phenyl benzoate (PB) was used as substrate, about 65% of total activity was resistant to the non-promoter mipafox (up to 0.5 mM, 20 min, pH 8.0), that inhibits NTE and other esterases. More than 90% of this resistant activity was sensitive to the classical promoter PMSF (1 mM, 20 min, pH 8.0) with an IC 50 of about 0.08 mM (20 min, pH 8.0). On the contrary, the non-promoter p-toluene sulfonyl fluoride caused only about 10% inhibition at 0.5 mM. Several esterase inhibitors including, paraoxon, phenyl benzyl carbamate, di-n-butyl dichlorovinyl phosphate and di-isopropyl fluorophosphate, were tested both in vitro and in vivo for inhibition of this PB activity. Mipafox-resistant PMSF-sensitive PB esterase activity(ies) was inhibited by promoters but not by non promoters and neuropathic compounds

  14. Esterase Active in Polar Organic Solvents from the Yeast Pseudozyma sp. NII 08165

    Directory of Open Access Journals (Sweden)

    Deepthy Alex

    2014-01-01

    Full Text Available Esterases/lipases active in water miscible solvents are highly desired in biocatalysis where substrate solubility is limited and also when the solvent is desired as an acyl acceptor in transesterification reactions, as with the case of biodiesel production. We have isolated an esterase from the glycolipid producing yeast-Pseudozyma sp. NII 08165 which in its crude form was alkali active, thermo stable, halo tolerant and also capable of acting in presence of high methanol concentration. The crude enzyme which maintained 90% of its original activity after being treated at 70°C was purified and the properties were characterized. The partially purified esterase preparation had temperature and pH optima of 60°C and 8.0 respectively. The enzyme retained almost complete activity in presence of 25% methanol and 80% activity in the same strength of ethanol. Conditions of enzyme production were optimized, which lead to 9 fold increase in the esterase yield. One of the isoforms of the enzyme LIP1 was purified to homogeneity and characterized. Purified LIP1 had a Km and Vmax of 0.01 and 1.12, respectively. The purified esterase lost its thermo and halo tolerance but interestingly, retained 97% activity in methanol.

  15. Gender differences in the activities of aspirin-esterases in rat tissues

    Directory of Open Access Journals (Sweden)

    Benedito M.A.C.

    1998-01-01

    Full Text Available The activities of aspirin (acetylsalicylic acid-esterases were measured in several tissues (liver, kidney, adrenal glands, brain and serum from adult male and female Wistar rats. In males, both aspirin-esterase I (assayed at pH 5.5 and II (assayed at pH 7.4 activities were higher in liver homogenates when compared to females (aspirin-esterase I: males 48.9 ± 4.8 (N = 8 and females 29.3 ± 4.2 (N = 8 nmol of salicylic acid formed min-1 mg protein-1; aspirin-esterase II: males 41.4 ± 4.1 (N = 8 and females 26.1 ± 4.5 (N = 8 nmol of salicylic acid formed min-1 mg protein-1, P<0.001. In serum, enzyme activity was higher in females than in males (aspirin-esterase I: males 0.85 ± 0.06 (N = 6 and females 1.18 ± 0.11 (N = 6 nmol of salicylic acid formed min-1 mg protein-1; aspirin-esterase II: males 1.03 ± 0.13 (N = 6 and females 1.34 ± 0.11 (N = 6 nmol of salicylic acid formed min-1 mg protein-1, P<0.001. In the other tissues assayed, no statistically significant difference between males and females was found. There were no statistically significant differences when the enzymes were assayed in different phases of the estrous cycle in liver and serum. These results show that the differences in aspirin-esterase activity observed between males and females are not due to the estrous cycle. The gender difference obtained in our study may indicate an involvement of gonadal hormones in the control of the hydrolysis of aspirin. This possibility is currently under investigation.

  16. A cold-induced pectin methyl-esterase inhibitor gene contributes negatively to freezing tolerance but positively to salt tolerance in Arabidopsis.

    Science.gov (United States)

    Chen, Jian; Chen, Xuehui; Zhang, Qingfeng; Zhang, Yidan; Ou, Xiangli; An, Lizhe; Feng, Huyuan; Zhao, Zhiguang

    2018-03-01

    Plant pectin methyl-esterase (PME) and PME inhibitor (PMEI) belong to large gene families whose members are proposed to be widely involved in growth, development, and stress responses; however, the biological functions of most PMEs and PMEIs have not been characterized. In this study, we studied the roles of CbPMEI1, a cold-induced pectin methyl-esterase inhibitor (PMEI) gene from Chorispora bungeana, under freezing and salt stress. The putative CbPMEI1 peptide shares highest similarity (83%) with AT5G62360 (PMEI13) of Arabidopsis. Overexpression of either CbPMEI1 or PMEI13 in Arabidopsis decreased tissue PME activity and enhanced the degree of methoxylation of cell wall pectins, indicating that both genes encode functional PMEIs. CbPMEI1 and PMEI13 were induced by cold but repressed by salt stress and abscisic acid, suggesting distinct roles of the genes in freezing and salt stress tolerance. Interestingly, transgenic Arabidopsis plants overexpressing CbPMEI1 or PMEI13 showed decreased freezing tolerance, as indicated by survival and electrolyte leakage assays. On the other hand, the salt tolerance of transgenic plants was increased, showing higher rates of germination, root growth, and survival under salinity conditions as compared with non-transgenic wild-type plants. Although the transgenic plants were freezing-sensitive, they showed longer roots than wild-type plants under cold conditions, suggesting a role of PMEs in balancing the trade-off between freezing tolerance and growth. Thus, our study indicates that CbPMEI1 and PMEI13 are involved in root growth regulation under cold and salt stresses, and suggests that PMEIs may be potential targets for genetic engineering aimed to improve fitness of plants under stress conditions. Copyright © 2018 Elsevier GmbH. All rights reserved.

  17. In-vivo measurements of regional acetylcholine esterase activity in degenerative dementia: comparison with blood flow and glucose metabolism.

    Science.gov (United States)

    Herholz, K; Bauer, B; Wienhard, K; Kracht, L; Mielke, R; Lenz, M O; Strotmann, T; Heiss, W D

    2000-01-01

    Memory and attention are cognitive functions that depend heavily on the cholinergic system. Local activity of acetylcholine esterase (AChE) is an indicator of its integrity. Using a recently developed tracer for positron emission tomography (PET), C-11-labeled N-methyl-4-piperidyl-acetate (C11-MP4A), we measured regional AChE activity in 4 non-demented subjects, 4 patients with dementia of Alzheimer type (DAT) and 1 patient with senile dementia of Lewy body type (SDLT), and compared the findings with measurements of blood flow (CBF) and glucose metabolism (CMRGlc). Initial tracer extraction was closely related to CBF. AChE activity was reduced significantly in all brain regions in demented subjects, whereas reduction of CMRGlc and CBF was more limited to temporo-parietal association areas. AChE activity in SDLT was in the lower range of values in DAT. Our results indicate that, compared to non-demented controls, there is a global reduction of cortical AChE activity in dementia. Dementia, cholinergic system, acetylcholine esterase, positron emission tomography, cerebral blood flow, cerebral glucose metabolism.

  18. Zymography Detection of a Bacterial Extracellular Thermoalkaline Esterase/Lipase Activity.

    Science.gov (United States)

    Tapizquent, María; Fernández, Marleny; Barreto, Georgina; Hernández, Zully; Contreras, Lellys M; Kurz, Liliana; Wilkesman, Jeff

    2017-01-01

    Lipases are esterases that occur widely in nature, yet those with commercial relevance are exclusively from microbial origin. Glycerol and long-chain fatty acids are the products after hydrolysis of esters bonds in saponifiable lipids catalyzed by lipases. In this work, we describe lipase/esterase activity contained in cell-free fractions from thermophilic bacteria, cultured in medium containing olive oil. Analysis of the cell-free fractions by electrotransference zymography, using tributyrin as substrate, revealed bands corresponding to lipase activity. The method is simple, fast, and inexpensive.

  19. Esterase and protease activities of Bacillus spp. from afitin, iru and ...

    African Journals Online (AJOL)

    The electrophoretic profiles of fermented African locust bean protein (ALBP), using strains presenting the highest protease activities in casein agar, were analyzed by SDS-PAGE to select strains with good ability to be used as starter cultures. All the Bacillus spp. tested showed esterase activity against tributyrin with high ...

  20. Cholesterol esterase inhibitory activity of bioactives from leaves of Mangifera indica L

    Science.gov (United States)

    Gururaja, G. M.; Mundkinajeddu, Deepak; Dethe, Shekhar M.; Sangli, Gopala K.; Abhilash, K.; Agarwal, Amit

    2015-01-01

    Background: In the earlier studies, methanolic extract of Mangifera indica L leaf was exhibited hypocholesterol activity. However, the bioactive compounds responsible for the same are not reported so far. Objective: To isolate the bioactive compounds with hypocholesterol activity from the leaf extract using cholesterol esterase inhibition assay which can be used for the standardization of extract. Materials and Methods: The leaf methanolic extract of M. indica (Sindoora variety) was partitioned with ethyl acetate and chromatographed on silica gel to yield twelve fractions and the activity was monitored by using cholesterol esterase inhibition assay. Active fractions were re-chromatographed to yield individual compounds. Results and Discussion: A major compound mangiferin present in the extract was screened along with other varieties of mango leaves for cholesterol esterase inhibition assay. However, the result indicates that compounds other than mangiferin may be active in the extract. Invitro pancreatic cholesterol esterase inhibition assay was used for bioactivity guided fractionation (BAGF) to yield bioactive compound for standardization of extract. Bioactivity guided fractionation afford the active fraction containing 3b-taraxerol with an IC50 value of 0.86μg/ml. Conclusion: This study demonstrates that M. indica methanol extract of leaf have significant hypocholesterol activity which is standardized with 3b-taraxerol, a standardized extract for hypocholesterol activity resulted in development of dietary supplement from leaves of Mangifera indica. PMID:26692750

  1. The effect of EDTA and metal cations on the 5-bromoindoxyl acetate esterase activity in the thyroid of the guinea pig

    DEFF Research Database (Denmark)

    Kirkeby, S

    1976-01-01

    Miscellaneous metal cations and EDTA have been used as activators and inhibitors of esterase activity in the thyroid of the guinea-pig. The results indicate that the 5-bromoiondoxyl acetate esterase in the epithelial cells probably consists of two different A-esterase isoenzymes, one present...

  2. BIIDXI, the At4g32460 DUF642 gene, is involved in pectin methyl esterase regulation during Arabidopsis thaliana seed germination and plant development.

    Science.gov (United States)

    Zúñiga-Sánchez, Esther; Soriano, Diana; Martínez-Barajas, Eleazar; Orozco-Segovia, Alma; Gamboa-deBuen, Alicia

    2014-12-02

    DUF642 proteins constitute a highly conserved family of proteins that are associated with the cell wall and are specific to spermatophytes. Transcriptome studies have suggested that members of this family are involved in seed development and germination processes. Previous in vitro studies have revealed that At4g32460- and At5g11420-encoded proteins interact with the catalytic domain of pectin methyl esterase 3 (AtPME3, which is encoded by At3g14310). PMEs play an important role in plant development, including seed germination. The aim of this study was to evaluate the function of the DUF642 gene At4g32460 during seed germination and plant development and to determine its relation to PME activity regulation. Our results indicated that the DUF642 proteins encoded by At4g32460 and At5g11420 could be positive regulators of PME activity during several developmental processes. Transgenic lines overexpressing these proteins showed increased PME activity during seed germination, and improved seed germination performance. In plants expressing At4g32460 antisense RNA, PME activity was decreased in the leaves, and the siliques were very short and contained no seeds. This phenotype was also present in the SALK_142260 and SALK_054867 lines for At4g32460. Our results suggested that the DUF642 family contributes to the complexity of the methylesterification process by participating in the fine regulation of pectin status during plant development.

  3. Mode of de-esterification of alkaline and acidic pectin methyl esterases at different pH conditions.

    Science.gov (United States)

    Duvetter, Thomas; Fraeye, Ilse; Sila, Daniel N; Verlent, Isabel; Smout, Chantal; Hendrickx, Marc; Van Loey, Ann

    2006-10-04

    Highly esterified citrus pectin was de-esterified at pH 4.5 and 8.0 by a fungal pectin methyl esterase (PME) that was shown to have an acidic isoelectric pH (pI) and an acidic pH optimum and by a plant PME that was characterized by an alkaline pI and an alkaline pH optimum. Interchain and intrachain de-esterification patterns were studied by digestion of the pectin products with endo-polygalacturonase and subsequent analysis using size exclusion and anion-exchange chromatography. No effect of pH was observed on the de-esterification mode of either of the two enzymes. Acidic, fungal PME converted pectin according to a multiple-chain mechanism, with a limited degree of multiple attack at the intrachain level, both at pH 4.5 and at pH 8.0. A multiple-attack mechanism, with a high degree of multiple attack, was more appropriate to describe the action mode of alkaline, plant PME, both at pH 4.5 and at pH 8.0.

  4. Textural properties of gelling system of low-methoxy pectins produced by demethoxylating reaction of pectin methyl esterase.

    Science.gov (United States)

    Kim, Y; Yoo, Y-H; Kim, K-O; Park, J-B; Yoo, S-H

    2008-06-01

    After deesterification of commercial pectins with a pectin methyl esterase (PME), their gelling properties were characterized using instrumental texture analysis. The final degree of esterification (DE) of the high- and low-methoxy pectins reached approximately 6% after the PME treatment, while deesterification of low-methoxy amidated pectin stopped at 18% DE. Furthermore, DE of high-methoxy pectin was tailored to be 40%, which is equivalent to the DE of commercial low-methoxy pectin. As a result, significant changes in molecular weight (Mw) distribution were observed in the PME-treated pectins. The texture profile analysis showed that PME modification drastically increased hardness, gumminess, and chewiness, while decreasing cohesiveness and adhesiveness of the pectin gels (P pectin gel with relatively high peak molecular weight (Mp, 3.5 x 10(5)) and low DE (6), which was produced from high-methoxy pectin, exhibited the greatest hardness, gumminess, chewiness, and resilience. The hardness of low-methoxy amidated pectin increased over 300% after PME deesterification, suggesting that the effects of amide substitution could be reinforced when DE is even lower. The partial least square regression analysis indicated that the Mw and DE of the pectin molecule are the most crucial factors for hardness, chewiness, gumminess, and resilience of gel matrix.

  5. Pectin methyl esterase treatment on high-methoxy pectin for making fruit jam with reduced sugar content.

    Science.gov (United States)

    Wang, Yuh-Tai; Lien, Ling-Lan; Chang, Ya-Chu; Wu, James Swi-Bea

    2013-01-01

    Pectin methyl esterase (PME) has been postulated to catalyse the transacylation reaction between pectin molecules. The present study aimed to prove the occurrence of this reaction. The feasibility of applying PME-catalysed transacylation between high-methoxy pectin molecules in making fruit jam with reduced sugar content was also investigated. PME treatment increased the turbidity and particle size in pectin solution and the molecular weight of pectin, while it decreased the number of methoxy ester linkages and the intensity of the CH₃ absorption peak in the Fourier transform infrared spectrum without changes in the number of total ester linkages in pectin molecules. These findings support the occurrence of PME-catalysed transacylation between pectin molecules. Higher values of hardness, gumminess and chewiness were found in a jam containing PME-treated citrus pectin (10 g L⁻¹) and sugar (350 g L⁻¹) as compared with either a jam containing untreated citrus pectin (10 g L⁻¹) and sugar (350 g L⁻¹) or strawberry jam containing pectin (10 g L⁻¹) from the fruit and sugar (650 g L⁻¹). The demand for sugar in jam making can be greatly reduced by the use of PME-treated high-methoxy pectin. Copyright © 2012 Society of Chemical Industry.

  6. Wounding coordinately induces cell wall protein, cell cycle and pectin methyl esterase genes involved in tuber closing layer and wound periderm development.

    Science.gov (United States)

    Neubauer, Jonathan D; Lulai, Edward C; Thompson, Asunta L; Suttle, Jeffrey C; Bolton, Melvin D

    2012-04-15

    Little is known about the coordinate induction of genes that may be involved in agriculturally important wound-healing events. In this study, wound-healing events were determined together with wound-induced expression profiles of selected cell cycle, cell wall protein, and pectin methyl esterase genes using two diverse potato genotypes and two harvests (NDTX4271-5R and Russet Burbank tubers; 2008 and 2009 harvests). By 5 d after wounding, the closing layer and a nascent phellogen had formed. Phellogen cell divisions generated phellem layers until cessation of cell division at 28 d after wounding for both genotypes and harvests. Cell cycle genes encoding epidermal growth factor binding protein (StEBP), cyclin-dependent kinase B (StCDKB) and cyclin-dependent kinase regulatory subunit (StCKS1At) were induced by 1 d after wounding; these expressions coordinated with related phellogen formation and the induction and cessation of phellem cell formation. Genes encoding the structural cell wall proteins extensin (StExt1) and extensin-like (StExtlk) were dramatically up-regulated by 1-5 d after wounding, suggesting involvement with closing layer and later phellem cell layer formation. Wounding up-regulated pectin methyl esterase genes (StPME and StPrePME); StPME expression increased during closing layer and phellem cell formation, whereas maximum expression of StPrePME occurred at 5-14 d after wounding, implicating involvement in later modifications for closing layer and phellem cell formation. The coordinate induction and expression profile of StTLRP, a gene encoding a cell wall strengthening "tyrosine-and lysine-rich protein," suggested a role in the formation of the closing layer followed by phellem cell generation and maturation. Collectively, the genes monitored were wound-inducible and their expression profiles markedly coordinated with closing layer formation and the index for phellogen layer meristematic activity during wound periderm development; results were more

  7. Comparison of esterase gene amplification, gene expression and esterase activity in insecticide susceptible and resistant strains of the brown planthopper, Nilaparvata lugens (Stål).

    Science.gov (United States)

    Vontas, J G; Small, G J; Hemingway, J

    2000-12-01

    Organophosphorus and carbamate insecticide resistance in Nilaparvata lugens is based on amplification of a carboxylesterase gene, Nl-EST1. An identical gene occurs in susceptible insects. Quantitative real-time PCR was used to demonstrate that Nl-EST1 is amplified 3-7-fold in the genome of resistant compared to susceptible planthoppers. Expression levels were similar to amplification levels, with 1-15-fold more Nl-EST1 mRNA in individual insects and 5-11-fold more Nl-EST1 mRNA in mass whole body homogenates of resistant females compared to susceptibles. These values corresponded to an 8-10-fold increase in esterase activity in the head and thorax of individual resistant insects. Although amplification, expression and activity levels of Nl-EST1 in resistant N. lugens were similar, the correlation between esterase activity and Nl-EST1 mRNA levels in resistant individuals was not linear.

  8. Esterases activity in the axolotl Ambystoma mexicanum exposed to chlorpyrifos and its implication to motor activity.

    Science.gov (United States)

    Robles-Mendoza, Cecilia; Zúñiga-Lagunes, Sebastian R; Ponce de León-Hill, Claudia A; Hernández-Soto, Jesús; Vanegas-Pérez, Cecilia

    2011-10-01

    The axolotl Ambystoma mexicanum is a neotenic salamander considered a good biological model due to its ability to regenerate limbs, tail, brain and heart cells. Nevertheless, severe reduction of A. mexicanum wild populations in the lacustrine area of Xochimilco, the natural habitat of the axolotl, could be related to several environmental pressures as the presence of organophosphate pesticides (OPPs), intensively applied in agricultural activities in Xochimilco. Thus the aim of this study was to evaluate the effect of environmentally realistic chlorpyrifos (CPF) concentrations, a OPP commonly used in this zone, on esterases activity (acetylcholinesterase and carboxylesterase) and bioconcentration of CPF and to relate them with the motor activity of A. mexicanum juveniles. Axolotls were exposed 48 h to 0.05 and 0.1mg CPF/L, and the responses were evaluated at the end of the CPF exposure. Results suggest that CPF is bioconcentrated into axolotls and that the CPF internal concentrations are related with the observed inhibition activity of AChE (>50%) and CbE (≈ 50%). CPF concentration responsible of the inhibition of the 50% of AChE activity (IC50) was estimated in 0.04 mg CPF/L; however IC50 for CbE activity was not possible to calculate since inhibition levels were lower than 50%, results that suggest a higher resistance of CbE enzymatic activity to CPF. However, motor activity was a more sensitive endpoint to CPF poisoning since time that axolotls spent active and walking, frequency and speed of swimming, frequency of prey attack were reduced >90% of control groups. The motor activity alterations in the axolotl could be related with the registered esterases inhibition. Thus important alterations on axolotls were identified even at short time and low concentrations of CPF exposure. Also, it was possible to link biochemical responses as esterases activity with higher levels of biological organization as behavior. This study provides tools for the regulation of the

  9. Esterase activities of intracellular extracts of wild strains of lactic acid bacteria isolated from Serra da Estrela cheese

    OpenAIRE

    Macedo, Angela C.; Tavares, Tânia G.; Malcata, F. Xavier

    2003-01-01

    Lactococcus lactis subsp. lactis strain ESB110019 and Lactobacillus plantarum strain ESB5004, novel strains that were previously isolated from the wild adventitious microflora of certified Serra da Estrela cheeses, were assayed for esterase activity using, as substrates, ortho- and para-nitrophenyl derivatives of fatty acids. Both strains preferentially hydrolyzed short-chain fatty acids; L. lactis ESB110019 exhibited a stronger esterase activity than Lb. plantarum ESB5004 and cleaved the p-n...

  10. Environmental Factors Modulating the Stability and Enzymatic Activity of the Petrotoga mobilis Esterase (PmEst.

    Directory of Open Access Journals (Sweden)

    Jose L S Lopes

    Full Text Available Enzymes isolated from thermophilic organisms found in oil reservoirs can find applications in many fields, including the oleochemical, pharmaceutical, bioenergy, and food/dairy industries. In this study, in silico identification and recombinant production of an esterase from the extremophile bacteria Petrotoga mobilis (designated PmEst were performed. Then biochemical, bioinformatics and structural characterizations were undertaken using a combination of synchrotron radiation circular dichroism (SRCD and fluorescence spectroscopies to correlate PmEst stability and hydrolytic activity on different substrates. The enzyme presented a high Michaelis-Menten constant (KM 0.16 mM and optimum activity at ~55°C for p-nitrophenyl butyrate. The secondary structure of PmEst was preserved at acid pH, but not under alkaline conditions. PmEst was unfolded at high concentrations of urea or guanidine through apparently different mechanisms. The esterase activity of PmEst was preserved in the presence of ethanol or propanol and its melting temperature increased ~8°C in the presence of these organic solvents. PmEst is a mesophilic esterase with substrate preference towards short-to medium-length acyl chains. The SRCD data of PmEst is in agreement with the prediction of an α/β protein, which leads us to assume that it displays a typical fold of esterases from this family. The increased enzyme stability in organic solvents may enable novel applications for its use in synthetic biology. Taken together, our results demonstrate features of the PmEst enzyme that indicate it may be suitable for applications in industrial processes, particularly, when the use of polar organic solvents is required.

  11. Mechanism-Guided Discovery of an Esterase Scaffold with Promiscuous Amidase Activity

    Directory of Open Access Journals (Sweden)

    Charlotte Kürten

    2016-06-01

    Full Text Available The discovery and generation of biocatalysts with extended catalytic versatilities are of immense relevance in both chemistry and biotechnology. An enhanced atomistic understanding of enzyme promiscuity, a mechanism through which living systems acquire novel catalytic functions and specificities by evolution, would thus be of central interest. Using esterase-catalyzed amide bond hydrolysis as a model system, we pursued a simplistic in silico discovery program aiming for the identification of enzymes with an internal backbone hydrogen bond acceptor that could act as a reaction specificity shifter in hydrolytic enzymes. Focusing on stabilization of the rate limiting transition state of nitrogen inversion, our mechanism-guided approach predicted that the acyl hydrolase patatin of the α/β phospholipase fold would display reaction promiscuity. Experimental analysis confirmed previously unknown high amidase over esterase activity displayed by the first described esterase machinery with a protein backbone hydrogen bond acceptor to the reacting NH-group of amides. The present work highlights the importance of a fundamental understanding of enzymatic reactions and its potential for predicting enzyme scaffolds displaying alternative chemistries amenable to further evolution by enzyme engineering.

  12. Involvement of pectin methyl-esterase during the ripening of grape berries: partial cDNA isolation, transcript expression and changes in the degree of methyl-esterification of cell wall pectins.

    Science.gov (United States)

    Barnavon, L; Doco, T; Terrier, N; Ageorges, A; Romieu, C; Pellerin, P

    2001-11-01

    Grape berries (Vitis vinifera L., cv Ugni blanc) were harvested at 12 different weeks of development in 1996 and 1997. Ripening was induced at veraison, the crucial stage of berry softening, and was followed by a rapid accumulation of glucose and fructose and an increase of pH. Total RNAs, crude proteins and cell wall material were isolated from each developmental stage. A partial length cDNA (pme1, accession number AF159122, GenBank) encoding a pectin methyl-esterase (PME, EC 3.1.1.11) was cloned by RT-PCR with degenerate primers. Northern blots revealed that mRNAs coding for PME accumulate from one week before the onset of ripening until complete maturity, indicating that this transcript represents an early marker of veraison and could be involved in berry softening. However, PME activity was detected during all developmental stages. Total activity per berry increased, whereas "specific" activity, on a fresh weight basis, decreased during development. The amount of cell wall material (per berry and per g of berry) followed the same pattern as that of PME activity (total and "specific" respectively), indicating they were tightly correlated and that PME levels varied very little in the cell walls. Nevertheless, the degree of methyl-esterification of insoluble pectins decreased throughout the development from 68% in green stages to less than 20% for the ripe berries, and this observation is consistent with the induction of PME mRNAs during ripening. Relations between transcript expression, PME activity, the DE of insoluble pectic polysaccharides and their involvement in grape berry ripening are discussed.

  13. Arginine-esterase activity of kallikrein in the sera of whole-body irradiated rats and guinea-pigs

    Energy Technology Data Exchange (ETDEWEB)

    Pouckova, P; Pospisil, J; Dienstbier, Z [Karlova Univ., Prague (Czechoslovakia). Biofyzikalni Ustav

    1977-09-01

    In whole-body irradiated rats (800 R=LDsub(50/30)) and guinea pigs (300 R=LDsub(50/30)) changes were investigated in the arginine esterase activity of kallikrein in native serum as well as in serum exposed to contact with a clay suspension. From the values obtained the activity of prekallikrein was calculated. While in the rat serum significant changes in the arginine esterase activity of kallikrein were found, in the guinea pig serum the kallikrein activity did not change markedly. The activity of prekallikrein immediately after irradiation assumes a similar course in both types of laboratory animals while during later intervals a reverse pattern was observed.

  14. Inhibition of a ubiquitously expressed pectin methyl esterase in Solanum tuberosum L. affects plant growth, leaf growth polarity, and ion partitioning.

    Science.gov (United States)

    Pilling, J; Willmitzer, L; Bücking, H; Fisahn, J

    2004-05-01

    Two pectin methyl esterases (PMEs; EC 3.1.1.11) from Solanum tuberosum were isolated and their expression characterised. One partial clone ( pest1) was expressed in leaves and fruit tissue, while pest2 was a functional full-length clone and was expressed ubiquitously, with a preference for aerial organs. Potato plants were transformed with a chimeric antisense construct that was designed to simultaneously inhibit pest1 and pest2 transcript accumulation; however, reduction of mRNA levels was confined to pest2. The decrease in pest2 transcript was accompanied by up to 50% inhibition of total PME activity, which was probably due to the reduction of only one PME isoform. PME inhibition affected plant development as reflected by smaller stem elongation rates of selected transformants when compared with control plants, leading to a reduction in height throughout the entire course of development. Expansion rates of young developing leaves were measured simultaneously by two displacement transducers in the direction of the leaf tip (proximal-distal axis) and in the perpendicular direction (medial-lateral axis). Significant differences in leaf growth patterns were detected between wild-type and transgenic plants. We suggest that these visual phenotypes could be correlated with modifications of ion accumulation and partitioning within the transgenic plants. The ion-binding capacities of cell walls from PME-inhibited plants were specifically modified as they preferentially bound more sodium, but less potassium and calcium. X-ray microanalysis also indicated an increase in the concentration of several ions within the leaf apoplast of transgenic plants. Moreover, quantification of the total content of major cations revealed differences specific for a given element between the leaves of PME-inhibited and wild-type plants. Reduced growth rates might also be due to effects of PME inhibition on pectin metabolism, predominantly illustrated by an accumulation of galacturonic acid

  15. Esterase activity able to hydrolyze dietary antioxidant hydroxycinnamates is distributed along the intestine of mammals

    DEFF Research Database (Denmark)

    Andreasen, Mette Findal; Kroon, P A; Williamson, G

    2001-01-01

    and may contribute to the beneficial effects derived from consumption of cereal bran. However, these compounds are ester linked to the main polymers in the plant cell wall and cannot be absorbed in this complex form. The present work shows that esterases with activity toward esters of the major dietary......Hydroxycinnamic acids are effective antioxidants and are abundant components of plant cell walls, especially in cereal bran. For example, wheat and rye brans are rich sources of the hydroxycinnamates ferulic acid, sinapic acid, and p-coumaric acid. These phenolics are part of human and animal diets...

  16. Improved stability and catalytic activity of graphene oxide/chitosan hybrid beads loaded with porcine liver esterase.

    Science.gov (United States)

    Sunderrajan, Shruthi; Miranda, Lima Rose; Pennathur, Gautam

    2018-04-21

    Graphene oxide/chitosan and reduced graphene oxide/chitosan (GO/CS and RGO/CS) beads were prepared by precipitation with NaOH. Porcine liver esterase was immobilized on these beads to give GO/CS/E and RGO/CS/E beads. The optimum conditions for the maximum activity of RGO/CS/E beads were pH 8 and 50°C. The stability of the enzyme immobilized on GO/CS/E and RGO/CS/E was high in the pH range of 5-8. The GO/CS/E beads showed superior stability compared to that of the free enzyme and CS/E beads between 20 and 50°C. Kinetic analysis showed that GO/CS/E was a better catalyst than the RGO/CS/E beads with a lower K m value of 0.9 mM. The hybrid beads also retained more than 95% activity after 10 consecutive cycles. The GO/CS/E and RGO/CS/E beads retained 84% and 87% activity after 40 days at 4°C. The GO/CS/E beads were used for the successful hydrolysis of methyl 4-hydroxy benzoate.

  17. The activity of non-specific esterase in the thyroid epithelial cells of the guinea pig as influenced by various inhibitors and activators. A histochemical study

    DEFF Research Database (Denmark)

    Kirkeby, S

    1976-01-01

    The action of various inhibitors and activators upon esterase activity in the thyroid epithelial cells is demonstrated. The agents used were triorthocresylphosphate (TOCP), parachloromercuribenzoate (PCMB), Arsanillic acid, p-nitrophenyl dimethyl carbamate and bis p-nitrophenyl phosphate. TOCP wa...

  18. Evaluation of the nitrite and leukocyte esterase activity tests for the diagnosis of acute symptomatic urinary tract infection in men.

    NARCIS (Netherlands)

    Koeijers, J.J.; Kessels, A.G.H.; Nys, S.; Bartelds, A.; Donker, G.; Stobberingh, E.; Verbon, A.

    2007-01-01

    For 422 male patients with symptoms indicative of a urinary tract infection, nitrite and leukocyte esterase activity dipstick test results were compared with results of culture of urine samples. The positive predictive value of a positive nitrite test result was 96%. Addition of results of the

  19. Spatial distribution and esterase activity in populations of Aedes (Stegomyia aegypti (Linnaeus (Diptera: Culicidae resistant to temephos

    Directory of Open Access Journals (Sweden)

    Wanessa Porto Tito Gambarra

    2013-04-01

    Full Text Available INTRODUCTION: The need for studies that describe the resistance patterns in populations of Aedes aegypti (Linnaeus in function of their region of origin justified this research, which aimed to characterize the resistance to temephos and to obtain information on esterase activity in populations of Aedes aegypti collected in municipalities of the State of Paraíba. METHODS: Resistance to temephos was evaluated and characterized from the diagnostic dose of 0.352mg i.a./L and multiple concentrations that caused mortalities between 5% and 99%. Electrophoresis of isoenzymes was used to verify the patterns of esterase activity among populations of the vector. RESULTS: All populations of Aedes aegypti were resistant to temephos, presenting a resistance rate (RR greater than 20. The greatest lethal dose 50% of the sample (CL50 was found for the municipality of Lagoa Seca, approximately forty-one times the value of CL50 for the Rockefeller population. The populations characterized as resistant showed two to six regions of α and β-esterase, called EST-1 to EST-6, while the susceptible population was only seen in one region of activity. CONCLUSIONS: Aedes aegypti is widely distributed and shows a high degree of resistance to temephos in all municipalities studied. In all cases, esterases are involved in the metabolism and, consequently, in the resistance to temephos.

  20. Synthesis activity-based zymography for detection of lipases and esterases.

    Science.gov (United States)

    Kwon, Min-A; Kim, Hyun Suk; Hahm, Dae-Hyun; Song, Jae Kwang

    2011-04-01

    A new zymography method for lipases and esterases was developed on the basis of the esterification reaction between fatty acids and alcohols. The enzymes were separated by SDS-PAGE and native PAGE. The gel was washed and then incubated in an aqueous solution containing fatty acids (oleic acid 18:1 or caprylic acid 8:0) and dodecanol. Synthesis was visualized by in situ precipitation of water-insoluble and non-diffusible fatty acid esters, such as dodecyl oleate and dodecyl octanoate. The synthesis activity-based zymography was confirmed with different enzyme samples, including commercial lipase preparations, purified recombinant lipase and cutinase, and crude culture supernatants of lipolytic enzyme-producing soil bacteria.

  1. Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

    Science.gov (United States)

    Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

    2009-01-01

    Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that

  2. Analysing deltamethrin susceptibility and pyrethroid esterase activity variations in sylvatic and domestic Triatoma infestans at the embryonic stage

    Directory of Open Access Journals (Sweden)

    Pablo Luis Santo-Orihuela

    2013-12-01

    Full Text Available The aim of the present work was to study the deltamethrin susceptibility of eggs from Triatoma infestans populations and the contribution of pyrethroid esterases to deltamethrin degradation. Insects were collected from sylvatic areas, including Veinte de Octubre and Kirus-Mayu (Bolivia and from domiciliary areas, including El Palmar (Bolivia and La Pista (Argentina. Deltamethrin susceptibility was determined by dose-response bioassays. Serial dilutions of deltamethrin (0.0005-1 mg/mL were topically applied to 12-day-old eggs. Samples from El Palmar had the highest lethal dose ratio (LDR value (44.90 compared to the susceptible reference strain (NFS, whereas the Veinte de Octubre samples had the lowest value (0.50. Pyrethroid esterases were evaluated using 7-coumaryl permethrate (7-CP on individually homogenised eggs from each population and from NFS. The El Palmar and La Pista samples contained 40.11 and 36.64 pmol/min/mg protein, respectively, and these values were statistically similar to NFS (34.92 pmol/min/mg protein and different from Kirus-Mayu and Veinte de Octubre (27.49 and 22.69 pmol/min/mg protein, respectively. The toxicological data indicate that the domestic populations were resistant to deltamethrin, but no statistical contribution of 7-CP esterases was observed. The sylvatic populations had similar LDR values to NFS, but lower 7-CP esterase activities. Moreover, this is the first study of the pyrethroid esterases on T. infestans eggs employing a specific substrate (7-CP.

  3. Multiple nucleophilic elbows leading to multiple active sites in a single module esterase from Sorangium cellulosum

    DEFF Research Database (Denmark)

    Udatha, D.B.R.K. Gupta; Madsen, Karina Marie; Panagiotou, Gianni

    2015-01-01

    The catalytic residues in carbohydrate esterase enzyme families constitute a highly conserved triad: serine, histidine and aspartic acid. This catalytic triad is generally located in a very sharp turn of the protein backbone structure, called the nucleophilic elbow and identified by the consensus...... sequence GXSXG. An esterase from Sorangium cellulosum Soce56 that contains five nucleophilic elbows was cloned and expressed in Escherichia coli and the function of each nucleophilic elbowed site was characterized. In order to elucidate the function of each nucleophilic elbow, site directed mutagenesis....... To our knowledge, this is the first report presenting the role of multiple nucleophilic elbows in the catalytic promiscuity of an esterase. Further structural analysis at protein unit level indicates the new evolutionary trajectories in emerging promiscuous esterases....

  4. Acetylcholine esterase activity in mild cognitive impairment and Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, Karl [University of Manchester, Wolfson Molecular Imaging Centre, Clinical Neuroscience, Manchester (United Kingdom); University of Cologne, Cologne (Germany)

    2008-03-15

    Impairment of cholinergic neurotransmission is a well-established fact in Alzheimer's disease (AD), but there is controversy about its relevance at the early stages of the disease and in mild cognitive impairment (MCI). In vivo positron emission tomography imaging of cortical acetylcholine esterase (AChE) activity as a marker of cholinergic innervation that is expressed by cholinergic axons and cholinoceptive neurons has demonstrated a reduction of this enzyme activity in manifest AD. The technique is also useful to measure the inhibition of cerebral AChE induced by cholinesterase inhibitors for treatment of dementia symptoms. A reduction of cortical AchE activity was found consistently in all studies of AD and in few cases of MCI who later concerted to AD. The in vivo findings in MCI and very mild AD are still preliminary, and studies seem to suggest that cholinergic innervation and AChE as the main degrading enzyme are both reduced, which might result in partial compensation of their effect. (orig.)

  5. In-gel detection of esterase-like albumin activity: Characterization of esterase-free sera albumin and its putative role as non-invasive biomarker of hepatic fibrosis

    Directory of Open Access Journals (Sweden)

    Areeba Ahmad

    2017-07-01

    Full Text Available Albumin is a globular and un-glycosylated multifunctional plasma protein and thus correlated with several human diseases. Owing to esterase contamination, albumin levels are usually misleading. In this study, we propose methodical accuracy for albumin estimation taking healthy and fibrotic rats. Liver fibrosis in rats was generated by N′-Nitrosodimethylamine (NDMA (10 mg/kg body weight within three weeks followed by its confirmation through H&E and immunohistochemical staining for α-SMA expression. Animal sera were screened by native polyacrylamide gel electrophoresis (native-PAGE (7.5%. In-gel esterase-like albumin activity was detected using α- and β-naphthyl acetate (5.58 × 10−3 mM; pH 7.5 as substrate. Sera albumin was purified from unstained PA gel-slices through electroelution. Subsequent to conformation of albumin purity by its molecular weight determination using SDS–PAGE (10% and peptide mass fingerprinting by MALDI-TOF-MS, samples were treated with different concentrations of urea. Urea-treated albumins were screened for esterase activity, conformational change and, albumin levels by immunoblotting. Our results demonstrate that esterase-like albumin activity in rat sera albumin is located in domain-III. The esterase-like activity remains detectable up to 4 M urea, which diminishes with increasing urea concentrations. Further, immunoblotting of urea-treated albumin samples displays a significant decline in purified protein bands, indicating hypoalbuminemia during hepatic fibrosis in rats. In conclusion, the present approach of albumin separation and estimation is of potential interest and may be recommended for diagnostic purposes.

  6. Identification of novel esterase-active enzymes from hot environments by use of the host bacterium Thermus thermophilus

    Directory of Open Access Journals (Sweden)

    Benedikt eLeis

    2015-04-01

    Full Text Available Functional metagenomic screening strategies, which are independent of known sequence information, can lead to the identification of truly novel genes and enzymes. Since E. coli has been used exhaustively for this purpose as a host, it is important to establish alternative expression hosts and to use them for functional metagenomic screening for new enzymes. In this study we show that Thermus thermophilus HB27 is an excellent screening host and can be used as an alternative provider of truly novel biocatalysts. In a previous study we constructed the mutant strain BL03 that was no longer able to grow on defined minimal medium supplemented with tributyrin as the sole carbon source and could be used as a host to screen for metagenomic DNA fragments that could complement growth on tributyrin. Several thousand single fosmid clones from thermophilic metagenomic libraries from heated compost and hot spring water samples were subjected to a comparative screening for esterase activity in both T. thermophilus strain BL03 and E. coli EPI300. We scored a greater number of active clones in the thermophilic bacterium than in the mesophilic E. coli. From all clones functionally screened in E. coli, only two thermostable α/β-fold hydrolase enzymes with high amino acid sequence similarity to already characterized enzymes were identifiable. In contrast, five further fosmids were found that conferred lipolytic activities in T. thermophilus. Four open reading frames (ORFs were found which did not share significant similarity to known esterase enzymes. Two of the genes were expressed in both hosts and the novel thermophilic esterases, which based on their primary structures could not be assigned to known esterase or lipase families, were purified and preliminarily characterized. Our work underscores the benefit of using additional screening hosts other than E. coli for the identification of novel biocatalysts with industrial relevance.

  7. Vaginal Fornix Discharge Cellularity and Its Leukocyte Esterase Activity for Diagnosis of Endometritis in Dairy Cows

    Directory of Open Access Journals (Sweden)

    Abolfazl HAJIBEMANI

    2016-01-01

    Full Text Available The objective of the present study was to evaluate the application of some strip test markers (i.e., leukocyte esterase (LE activity, protein, nitrate and pH for diagnosis of endometritis in dairy cows using vaginal fornix discharge. Also, the total white blood cell count (t-WBC/l of this secretion and degenerative changes of neutrophils in cervical cytology were used as alternative methods to predict progression of the endometritis severity. Holstein cows (n=215 between 30-40 days in milk (DIM were included and examined. Giemsa-stained smear was prepared from cervical mucus. Cervical cytology test was considered as reference screening method for the detection of subclinical endometritis. The LE activity and t-WBC in the vaginal fornix discharge of subclinical endometritis cows were significantly higher than those from healthy cows. Sensitivity and specificity were 78% and 73% for LE10 activity (10 minutes after contacting with discharges and 60% and 69% for t-WBC (cut off point=210 cells/l for diagnosis of subclinical endometritis, respectively. There was a good agreement between LE10 activity, t-WBC and cervical cytology test with a Kappa coefficient of 0.4 and 0.42, respectively (P<0.0001. Total WBC count in discharge and degenerative neutrophils (DN percentages increase simultaneously with the degree and severity of endometritis. There was a highly significant (P<0.01 correlation between t-WBC and some reagent strip test markers (LE activity, protein and nitrate in clear discharge of studied cows. In conclusion, the present results suggest the LE activity and t-WBC in vaginal fornix discharge could be used as non-invasive reliable and valid methods for screening of subclinical endometritis in postpartum dairy herds.

  8. Immobilization of cholesterol esterase in mesoporous silica materials and its hydrolytic activity toward diethyl phthalate

    Energy Technology Data Exchange (ETDEWEB)

    Orita, Toru, E-mail: nqj45366@nifty.com [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Taiyo Kagaku Co. Ltd., 800 Yamada-cho, Yokkaichi, Mie 512-1111 (Japan); Tomita, Masahiro [Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-cho, Tsu, Mie 514-8570 (Japan); Saito, Takao; Nishida, Nasakazu; Kato, Katsuya [National Institute of Advanced Industrial Science and Technology, 2266-78 Anagahora, Moriyamaku, Nagoya, Aichi 463-8560 (Japan)

    2012-05-01

    Cholesterol esterase (CE, cholesteryl ester hydrolase, EC 3.1.1.13) from porcine pancreas (molecular weight 400-500 kDa) exhibits hydrolytic activity toward various toxic organic phthalate esters. CE was confined in the nanospace (diameter 3-30 nm) of five types of mesoporous silica (MPS) that differ in structural properties such as pore diameter, pore volume, and particle morphology. These structural properties were characterized by transmission electron microscopy, small-angle X-ray diffraction, N{sub 2} adsorption-desorption experiments, solid-state {sup 13}C nuclear magnetic resonance (NMR), and solid-state {sup 29}Si NMR. Catalytic activities of immobilized and free CE were evaluated by the hydrolysis of diethyl phthalate in phosphate buffer solutions containing an organic cosolvent. Optimal activity recovery was achieved when CE was immobilized in n-decane-functionalized MPS, which had a large pore size (22.5 nm). The immobilization also protected against effects of temperature within the range 30 Degree-Sign C-60 Degree-Sign C; CE immobilized in n-decyl-functionalized MPS exhibited better thermal stability than in non-functionalized MPS or free CE. Moreover, it retained approximately 60% of its catalytic activity even after six catalytic cycles. - Highlights: Black-Right-Pointing-Pointer The highest activity of immobilized CE was shown in MPS with a pore size of 22.5 nm. Black-Right-Pointing-Pointer Catalytic efficiency improved when MPS was functionalized by n-decyl substitution. Black-Right-Pointing-Pointer Immobilized CE exhibited good thermal stability and reusability. Black-Right-Pointing-Pointer Organic co-solvent and the substrate structures affected enzyme activities.

  9. Genome-wide characterization of pectin methyl esterase genes reveals members differentially expressed in tolerant and susceptible wheats in response to Fusarium graminearum.

    Science.gov (United States)

    Zega, Alessandra; D'Ovidio, Renato

    2016-11-01

    Pectin methyl esterase (PME) genes code for enzymes that are involved in structural modifications of the plant cell wall during plant growth and development. They are also involved in plant-pathogen interaction. PME genes belong to a multigene family and in this study we report the first comprehensive analysis of the PME gene family in bread wheat (Triticum aestivum L.). Like in other species, the members of the TaPME family are dispersed throughout the genome and their encoded products retain the typical structural features of PMEs. qRT-PCR analysis showed variation in the expression pattern of TaPME genes in different tissues and revealed that these genes are mainly expressed in flowering spikes. In our attempt to identify putative TaPME genes involved in wheat defense, we revealed a strong variation in the expression of the TaPME following Fusarium graminearum infection, the causal agent of Fusarium head blight (FHB). Particularly interesting was the finding that the expression profile of some PME genes was markedly different between the FHB-resistant wheat cultivar Sumai3 and the FHB-susceptible cultivar Bobwhite, suggesting a possible involvement of these PME genes in FHB resistance. Moreover, the expression analysis of the TaPME genes during F. graminearum progression within the spike revealed those genes that responded more promptly to pathogen invasion. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Endophytic fungi producing of esterases: evaluation in vitro of the enzymatic activity using pH indicator

    Directory of Open Access Journals (Sweden)

    Helen Cristina Fávero Lisboa

    2013-09-01

    Full Text Available A sensitive and efficient colorimetric method was optimized for detection of esterase enzymes produced by endophytic fungi for development of High-Throughput Screening (HTS. The fungi were isolated and obtained previously from plant species of Cerrado and Atlantic Forest located in areas of environmental preservation in the State of Sao Paulo / Brazil, as part of the project "Chemical and biological prospecting endophytic fungi associated to plant species of Cerrado and Atlantic Forest". The compounds ethyl butyrate, ethyl acetate and methyl propionate were used as standards esters which were hydrolyzed by extracellular enzyme from endophytic fungi (EC. 3.1.1.1 -carboxylesterases for production of carboxylic acids. Thus, the reduction of the pH increases the protonated indicator concentration (bromothymol blue, changing the color of the reaction medium (from blue to yellow, that can be observed and measured by spectrophotometry at 616 nm. The methodology with acid-base indicator was performed on 13 microorganisms, aiming Periconia atropurpurea asapotential source of esterase for biotransformation of short chain esters. The results also evidenced that this methodology showed to be efficient, fast, cheap, having low consumption of reagents and easy development, and can be applied to screen carboxylic-ester hydrolases in a large number of microorganisms.

  11. Effect of halogenated benzenes on acetanilide esterase, acetanilide hydroxylase and procaine esterase in rats.

    Science.gov (United States)

    Carlson, G P; Dziezak, J D; Johnson, K M

    1979-07-01

    1,2,4-Trichlorobenzene, 1,3,5-trichlorobenzene, hexachlorobenzene, 1,2,4-tribromobenzene, 1,3,5-tribromobenzene and hexabromobenzene were compared for their abilities to induce acetanilide esterase, acentailide hydroxylase and procaine esterase. Except for hexabromobenzene all induced acetanilide esterase whereas the hydroxylation of acetanilide was seen only with the fully halogenated benzenes and with 1,3,5-tribromobenzene. Hepatic procaine esterase activity was increased by the three chlorinated benzenes and 1,2,4-tribromobenzene.

  12. A stereospecific carboxyl esterase from Bacillus coagulans hosting nonlipase activity within a lipase-like fold.

    Science.gov (United States)

    De Vitis, Valerio; Nakhnoukh, Cristina; Pinto, Andrea; Contente, Martina L; Barbiroli, Alberto; Milani, Mario; Bolognesi, Martino; Molinari, Francesco; Gourlay, Louise J; Romano, Diego

    2018-03-01

    Microbial carboxylesterases are important biocatalysts that selectively hydrolyze an extensive range of esters. Here, we report the biochemical and structural characterization of an atypical carboxylesterase from Bacillus coagulans (BCE), endowed with high enantioselectivity toward different 1,2-O-isopropylideneglycerol (IPG or solketal) esters. BCE efficiently catalyzes the production of enantiopure (S)-IPG, a chiral building block for the synthesis of β-blockers, glycerophospholipids, and prostaglandins; efficient hydrolysis was observed up to 65 °C. To gain insight into the mechanistic bases of such enantioselectivity, we solved the crystal structures of BCE in apo- and glycerol-bound forms at resolutions of 1.9 and 1.8 Å, respectively. In silico docking studies on the BCE structure confirmed that IPG esters with small acyl chains (≤ C6) were easily accommodated in the active site pocket, indicating that small conformational changes are necessary to accept longer substrates. Furthermore, docking studies suggested that enantioselectivity may be due to an improved stabilization of the tetrahedral reaction intermediate for the S-enantiomer. Contrary to the above functional data implying nonlipolytic functions, BCE displays a lipase-like 3D structure that hosts a "lid" domain capping the main entrance to the active site. In lipases the lid mediates catalysis through interfacial activation, a process that we did not observe for BCE. Overall, we present the functional-structural properties of an atypical carboxyl esterase that has nonlipase-like functions, yet possesses a lipase-like 3D fold. Our data provide original enzymatic information in view of BCE applications as an inexpensive, efficient biocatalyst for the production of enantiopure (S)-IPG. Coordinates and structure factors have been deposited in the Protein Data Bank (www.rcsb.org) under accession numbers 5O7G (apo-BCE) and 5OLU (glycerol-bound BCE). © 2017 Federation of European Biochemical

  13. Esterase Isoenzyme Variants in Barley

    DEFF Research Database (Denmark)

    Hvid, S.; Nielsen, G.

    1977-01-01

    Gene symbols are proposed for 27 esterase isoenzyme alleles representing 10 loci in barley. Two new esterase loci, Est 9 and Est 10, each with an active and a silent allele, and three new alleles in previously described loci were found. A few chemical and physical characteristics of the different...... esterase isoenzyme systems were studied. The heat inactivation temperature differed for the isoenzymes coded by most of the loci, whereas the substrate and inhibitor specificity of the isoenzymes was less distinct. A possible relationship between some of the systems is discussed....

  14. Esterase profile of human masseter muscle

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D; Vilmann, H

    1988-01-01

    The esterase profile of fresh human masseter muscle was investigated by use of histochemistry and electrophoresis. The histochemical methods included reactions for alpha-naphthyl esterase, myofibrillar ATPase, reverse myofibrillar ATPase and succinic dehydrogenase. In frozen sections of the muscle...... the coloured reaction product for esterases was present both as a diffuse sarcoplasmic coloration and as distinct granules. The intensity of diffuse reaction was used to classify the muscle fibres as strongly, moderately and weakly reacting. The fibres with strong esterase activity belonged to Type I and ii......C. iM and Type II A fibres showed a moderate esterase reaction and Type II B fibres had a low activity. The electrophoretic gels stained for esterase activity showed that the human masseter muscle possesses a slow migrating double band with high enzyme activity and a cascade of faster migrating...

  15. SABP2, a methyl salicylate esterase is required for the systemic acquired resistance induced by acibenzolar-S-methyl in plants.

    Science.gov (United States)

    Tripathi, Diwaker; Jiang, Yu-Lin; Kumar, Dhirendra

    2010-08-04

    Tobacco SABP2, a 29kDa protein catalyzes the conversion of methyl salicylic acid (MeSA) into salicylic acid (SA) to induce SAR. Pretreatment of plants with acibenzolar-S-methyl (ASM), a functional analog of salicylic acid induces systemic acquired resistance (SAR). Data presented in this paper suggest that SABP2 catalyzes the conversion of ASM into acibenzolar to induce SAR. Transgenic SABP2-silenced tobacco plants when treated with ASM, fail to express PR-1 proteins and do not induce robust SAR expression. When treated with acibenzolar, full SAR is induced in SABP2-silenced plants. These results show that functional SABP2 is required for ASM-mediated induction of resistance. Copyright (c) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  16. Comparative Study of Esterase and Hemolytic Activities in Clinically Important Candida Species, Isolated From Oral Cavity of Diabetic and Non-diabetic Individuals.

    Science.gov (United States)

    Fatahinia, Mahnaz; Poormohamadi, Farzad; Zarei Mahmoudabadi, Ali

    2015-03-01

    Diabetes mellitus as a chronic metabolic disease occurs in patients with partial or complete deficiency of insulin secretion or disorder in action of insulin on tissue. The disease is known to provide conditions for overgrowth of Candida species. Candida spp. cause candidiasis by many virulence factors such as esterase, hemolysin and phospholipase. This study aimed to compare esterase and hemolytic activity in various Candida species isolated from oral cavity of diabetic and non-diabetic individuals. Swab samples were taken from 95 patients with diabetes (35 men and 60 women) and 95 normal persons (42 men and 53 women) and cultured on Sabouraud dextrose agar. Identification of isolated yeasts was performed by germ tube test, morphology on CHROMagar Candida medium, corn meal agar and ability to grow at 45°C. Hemolysin activity was evaluated using blood plate assay and esterase activity was determined using the Tween 80 opacity test. Different Candida species were isolated from 57 (60%) diabetic and 24 (25%) non-diabetic individuals. Esterase activity was detected in all Candida isolates. Only 21.6% of C. albicans from patients with diabetes had esterase activity as + 3, while it ranged from + 1 to + 2 in others. Hemolytic activity was determined in C. albicans, C. dubliniensis, C. glabrata and C. krusei as 0.79, 0.58, 0.66 and 0.74, respectively. Hemolytic activity was significantly different in the two groups of diabetics and non-diabetics. Oral carriage of C. albicans in the diabetic group (n = 42; 66.7%) was significantly greater than the control group (n = 16; 57.1%). Esterase activity of C. albicans in diabetic group was higher than non-diabetic group. Although C. albicans remains the most frequently pathogenic yeast for human, but other species are increasing.

  17. Heterologous expression, purification and characterization of three novel esterases secreted by the lignocellulolytic fungus Penicillium purpurogenum when grown on sugar beet pulp.

    Science.gov (United States)

    Oleas, Gabriela; Callegari, Eduardo; Sepúlveda, Romina; Eyzaguirre, Jaime

    2017-04-18

    The lignocellulolytic fungus, Penicillium purpurogenum, grows on a variety of natural carbon sources, among them sugar beet pulp. Culture supernatants of P. purpurogenum grown on sugar beet pulp were partially purified and the fractions obtained analyzed for esterase activity by zymograms. The bands with activity on methyl umbelliferyl acetate were subjected to mass spectrometry to identify peptides. The peptides obtained were probed against the proteins deduced from the genome sequence of P. purpurogenum. Eight putative esterases thus identified were chosen for future work. Their cDNAs were expressed in Pichia pastoris. The supernatants of the recombinant clones were assayed for esterase activity, and five of the proteins were active against one or more substrates: methyl umbelliferyl acetate, indoxyl acetate, methyl esterified pectin and fluorescein diacetate. Three of those enzymes were purified, further characterized and subjected to a BLAST search. Based on their amino acid sequence and properties, they were identified as follows: RAE1, pectin acetyl esterase (CAZy family CE 12); FAEA, feruloyl esterase (could not be assigned to a CAZy family) and EAN, acetyl esterase (former CAZy family CE 10). Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Characterization of a cold-active esterase from Serratia sp. and improvement of thermostability by directed evolution.

    Science.gov (United States)

    Jiang, Huang; Zhang, Shaowei; Gao, Haofeng; Hu, Nan

    2016-01-22

    In recent years, cold-active esterases have received increased attention due to their attractive properties for some industrial applications such as high catalytic activity at low temperatures. An esterase-encoding gene (estS, 909 bp) from Serratia sp. was identified, cloned and expressed in Escherichia coli DE3 (BL21). The estS encoded a protein (EstS) of 302 amino acids with a predicted molecular weight of 32.5 kDa. It showed the highest activity at 10 °C and pH 8.5. EstS was cold active and retained ~92 % of its original activity at 0 °C. Thermal inactivation analysis showed that the T1/2 value of EstS was 50 min at 50 °C (residual activity 41.23 %) after 1 h incubation. EstS is also quite stable in high salt conditions and displayed better catalytic activity in the presence of 4 M NaCl. To improve the thermo-stability of EstS, variants of estS gene were created by error-prone PCR. A mutant 1-D5 (A43V, R116W, D147N) that showed higher thermo-stability than its wild type predecessor was selected. 1-D5 showed enhanced T1/2 of 70 min at 50 °C and retained 63.29 % of activity after incubation at 50 °C for 60 min, which were about 22 % higher than the wild type (WT). CD spectrum showed that the secondary structure of WT and 1-D5 are more or less similar, but an increase in β-sheets was recorded, which enhanced the thermostability of mutant protein. EstS was a novel cold-active and salt-tolerant esterase and half-life of mutant 1-D5 was enhanced by 1.4 times compared with WT. The features of EstS are interesting and can be exploited for commercial applications. The results have also provided useful information about the structure and function of Est protein.

  19. Metagenomic mining of feruloyl esterases from termite enteric flora

    CSIR Research Space (South Africa)

    Rashamuse, K

    2014-01-01

    Full Text Available A metagenome expression library was created from Trinervitermes trinervoides termite hindgut symbionts and subsequently screened for feruloyl esterase (FAE) activities, resulting in seven recombinant fosmids conferring feruloyl esterase phenotypes...

  20. Effect of pectin methyl esterase and Ca²⁺ ions treatment on antioxidant capacity, shelf-life and quality of minimally processed pomegranate (Punica granatum L.) arils.

    Science.gov (United States)

    Kumar, Sunil; Kumar, Ramesh; Nambi, V E

    2016-03-01

    Pomegranate fruits are difficult to peel and once peeled, extracted arils have very short shelf-life. Therefore, present investigation was carried out to extend the shelf life of minimally processed pomegranate arils using pectin methyl esterase (PME) and CaCl2 treatment during refrigerated storage. The arils of freshly harvested pomegranate fruits (Punica granatum L.) were treated with different concentrations of food-grade PME (50-300 units) and calcium ions (0.5-2.0% CaCl₂) for a period of 5-30 min using response surface methodology. Treated and untreated arils were then packed in low density polyethylene bags (25 μ) and maintained under low temperature (5°C; 90% RH) for evaluating the physical, biochemical and microbial quality of pomegranate arils at four day interval. Physiological loss in weight increased during storage but no food-borne pathogens were found during 28 day of cold storage in treated arils. Color and firmness of both treated and untreated arils decreased during storage but it was better maintained in treated arils. The firmness was found to be 0.630 N in treated samples compared to untreated one (0.511 N) after 20 d of storage. Total antioxidant capacity, ferric reducing antioxidant power, polyphenol oxidase and lipoxygenase activities increased during storage. Treatment with 249.33 units of PME and 1.70% CaCl₂for an immersion time of 24.93 min was found to be most effective treatment for maintaining the quality of minimally processed arils for longer period. Sensory score was also higher in treated pomegranate arils that were quite acceptable even after 20 day of referigerated storage as against 12 day for untreated ones.

  1. Plasma-derived human C1-esterase inhibitor does not prevent mechanical ventilation-induced pulmonary complement activation in a rat model of Streptococcus pneumoniae pneumonia

    NARCIS (Netherlands)

    de Beer, F. M.; Aslami, H.; Hoeksma, J.; van Mierlo, G.; Wouters, D.; Zeerleder, S.; Roelofs, J. J. T. H.; Juffermans, N. P.; Schultz, M. J.; Lagrand, W. K.

    2014-01-01

    Mechanical ventilation has the potential to cause lung injury, and the role of complement activation herein is uncertain. We hypothesized that inhibition of the complement cascade by administration of plasma-derived human C1-esterase inhibitor (C1-INH) prevents ventilation-induced pulmonary

  2. Esterase activity in the guinea pig thyroid under normal and pathological conditions (vitamin A deficiency) with special regard to cyst-like structures

    DEFF Research Database (Denmark)

    Kirkeby, S

    1977-01-01

    By use of different activators and inhibitors, TOCP(tri-o-cresyl phosphate), PCMB (parachloromercury benzoate), NiCl2, Pb(NO3)2, HgCl2, Hg(NO3)2, eserine and sodium taurocholate, it is shown that the esterase in the cyst cells and in group I cells of the guinea pig thyroid probably are A...

  3. Three feruloyl esterases in Cellulosilyticum ruminicola H1 act synergistically to hydrolyze esterified polysaccharides.

    Science.gov (United States)

    Li, Jiabao; Cai, Shichun; Luo, Yuanming; Dong, Xiuzhu

    2011-09-01

    Feruloyl esterases (Faes) constitute a subclass of carboxyl esterases that specifically hydrolyze the ester linkages between ferulate and polysaccharides in plant cell walls. Until now, the described microbial Faes were mainly from fungi. In this study, we report that Cellulosilyticum ruminicola H1, a previously described fibrolytic rumen bacterium, possesses three different active feruloyl esterases, FaeI, FaeII, and FaeIII. Phylogenetic analysis classified the described bacterial Faes into two types, FaeI and FaeII in type I and FaeIII in type II. Substrate specificity assays indicated that FaeI is more active against the ester bonds in natural hemicelluloses and FaeIII preferentially attacks the ferulate esters with a small moiety, such as methyl groups, while FaeII is active on both types of substrates. Among the three feruloyl esterase genes, faeI was the only one induced significantly by xylose and xylan, while pectin appeared to moderately induce the three genes during the late log phase to stationary phase. Western blot analysis determined that FaeI and FaeIII were secreted and cytoplasmic proteins, respectively, whereas FaeII seemed to be cell associated. The addition of FaeI and FaeII but not FaeIII enhanced the activity of a xylanase on maize cob, suggesting a synergy of the former two with xylanase. Hence, we propose that the three feruloyl esterases work in concert to hydrolyze ferulate esters in natural hemicelluloses.

  4. Characterization and mode of action of two acetyl xylan esterases from Chrysosporium lucknowense C1 active towards acetylated xylans

    NARCIS (Netherlands)

    Pouvreau, L.A.M.; Jonathan, M.C.; Kabel, M.A.; Hinz, S.W.A.; Gruppen, H.; Schols, H.A.

    2011-01-01

    Two novel acetyl xylan esterases, Axe2 and Axe3, from Chrysosporium lucknowense (C1), belonging to the carbohydrate esterase families 5 and 1, respectively, were purified and biochemically characterized. Axe2 and Axe3 are able to hydrolyze acetyl groups both from simple acetylated

  5. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus), from India and its possible role in indoxacarb degradation.

    Science.gov (United States)

    Ramya, Shanivarsanthe Leelesh; Venkatesan, Thiruvengadam; Srinivasa Murthy, Kottilingam; Jalali, Sushil Kumar; Verghese, Abraham

    2016-01-01

    Diamondback moth (DBM), Plutella xylostella (Linnaeus), is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n=13) and adults (n=12) of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%), followed by bacilli (15.4%). Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%), bacilli (16.7%) and flavobacteria (16.7%). Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32μmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus - KC985225 and Pantoea agglomerans - KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26μmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  6. Detection of carboxylesterase and esterase activity in culturable gut bacterial flora isolated from diamondback moth, Plutella xylostella (Linnaeus, from India and its possible role in indoxacarb degradation

    Directory of Open Access Journals (Sweden)

    Shanivarsanthe Leelesh Ramya

    2016-06-01

    Full Text Available Abstract Diamondback moth (DBM, Plutella xylostella (Linnaeus, is a notorious pest of brassica crops worldwide and is resistant to all groups of insecticides. The insect system harbors diverse groups of microbiota, which in turn helps in enzymatic degradation of xenobiotic-like insecticides. The present study aimed to determine the diversity of gut microflora in DBM, quantify esterase activity and elucidate their possible role in degradation of indoxacarb. We screened 11 geographic populations of DBM in India and analyzed them for bacterial diversity. The culturable gut bacterial flora underwent molecular characterization with 16S rRNA. We obtained 25 bacterial isolates from larvae (n = 13 and adults (n = 12 of DBM. In larval gut isolates, gammaproteobacteria was the most abundant (76%, followed by bacilli (15.4%. Molecular characterization placed adult gut bacterial strains into three major classes based on abundance: gammaproteobacteria (66%, bacilli (16.7% and flavobacteria (16.7%. Esterase activity from 19 gut bacterial isolates ranged from 0.072 to 2.32 µmol/min/mg protein. Esterase bands were observed in 15 bacterial strains and the banding pattern differed in Bacillus cereus – KC985225 and Pantoea agglomerans – KC985229. The bands were characterized as carboxylesterase with profenofos used as an inhibitor. Minimal media study showed that B. cereus degraded indoxacarb up to 20%, so it could use indoxacarb for metabolism and growth. Furthermore, esterase activity was greater with minimal media than control media: 1.87 versus 0.26 µmol/min/mg protein. Apart from the insect esterases, bacterial carboxylesterase may aid in the degradation of insecticides in DBM.

  7. Probiotic Ferulic Acid Esterase Active Lactobacillus fermentum NCIMB 5221 APA Microcapsules for Oral Delivery: Preparation and in Vitro Characterization

    Directory of Open Access Journals (Sweden)

    Catherine Tomaro-Duchesneau

    2012-02-01

    Full Text Available Probiotics possess potential therapeutic and preventative effects for various diseases and metabolic disorders. One important limitation for the oral delivery of probiotics is the harsh conditions of the upper gastrointestinal tract (GIT which challenge bacterial viability and activity. One proposed method to surpass this obstacle is the use of microencapsulation to improve the delivery of bacterial cells to the lower GIT. The aim of this study is to use alginate-poly-L-lysine-alginate (APA microcapsules to encapsulate Lactobacillus fermentum NCIMB 5221 and characterize its enzymatic activity and viability through a simulated GIT. This specific strain, in previous research, was characterized for its inherent ferulic acid esterase (FAE activity which could prove beneficial in the development of a therapeutic for the treatment and prevention of cancers and metabolic disorders. Our findings demonstrate that the APA microcapsule does not slow the mass transfer of substrate into and that of the FA product out of the microcapsule, while also not impairing bacterial cell viability. The use of simulated gastrointestinal conditions led to a significant 2.5 log difference in viability between the free (1.10 × 104 ± 1.00 × 103 cfu/mL and the microencapsulated (5.50 × 106 ± 1.00 × 105 cfu/mL L. fermentum NCIMB 5221 following exposure. The work presented here suggests that APA microencapsulation can be used as an effective oral delivery method for L. fermentum NCIMB 5221, a FAE-active probiotic strain.

  8. Probiotic Ferulic Acid Esterase Active Lactobacillus fermentum NCIMB 5221 APA Microcapsules for Oral Delivery: Preparation and in Vitro Characterization

    Science.gov (United States)

    Tomaro-Duchesneau, Catherine; Saha, Shyamali; Malhotra, Meenakshi; Coussa-Charley, Michael; Kahouli, Imen; Jones, Mitchell L.; Labbé, Alain; Prakash, Satya

    2012-01-01

    Probiotics possess potential therapeutic and preventative effects for various diseases and metabolic disorders. One important limitation for the oral delivery of probiotics is the harsh conditions of the upper gastrointestinal tract (GIT) which challenge bacterial viability and activity. One proposed method to surpass this obstacle is the use of microencapsulation to improve the delivery of bacterial cells to the lower GIT. The aim of this study is to use alginate-poly-L-lysine-alginate (APA) microcapsules to encapsulate Lactobacillus fermentum NCIMB 5221 and characterize its enzymatic activity and viability through a simulated GIT. This specific strain, in previous research, was characterized for its inherent ferulic acid esterase (FAE) activity which could prove beneficial in the development of a therapeutic for the treatment and prevention of cancers and metabolic disorders. Our findings demonstrate that the APA microcapsule does not slow the mass transfer of substrate into and that of the FA product out of the microcapsule, while also not impairing bacterial cell viability. The use of simulated gastrointestinal conditions led to a significant 2.5 log difference in viability between the free (1.10 × 104 ± 1.00 × 103 cfu/mL) and the microencapsulated (5.50 × 106 ± 1.00 × 105 cfu/mL) L. fermentum NCIMB 5221 following exposure. The work presented here suggests that APA microencapsulation can be used as an effective oral delivery method for L. fermentum NCIMB 5221, a FAE-active probiotic strain. PMID:24288090

  9. Probiotic Ferulic Acid Esterase Active Lactobacillus fermentum NCIMB 5221 APA Microcapsules for Oral Delivery: Preparation and in Vitro Characterization.

    Science.gov (United States)

    Tomaro-Duchesneau, Catherine; Saha, Shyamali; Malhotra, Meenakshi; Coussa-Charley, Michael; Kahouli, Imen; Jones, Mitchell L; Labbé, Alain; Prakash, Satya

    2012-02-16

    Probiotics possess potential therapeutic and preventative effects for various diseases and metabolic disorders. One important limitation for the oral delivery of probiotics is the harsh conditions of the upper gastrointestinal tract (GIT) which challenge bacterial viability and activity. One proposed method to surpass this obstacle is the use of microencapsulation to improve the delivery of bacterial cells to the lower GIT. The aim of this study is to use alginate-poly-L-lysine-alginate (APA) microcapsules to encapsulate Lactobacillus fermentum NCIMB 5221 and characterize its enzymatic activity and viability through a simulated GIT. This specific strain, in previous research, was characterized for its inherent ferulic acid esterase (FAE) activity which could prove beneficial in the development of a therapeutic for the treatment and prevention of cancers and metabolic disorders. Our findings demonstrate that the APA microcapsule does not slow the mass transfer of substrate into and that of the FA product out of the microcapsule, while also not impairing bacterial cell viability. The use of simulated gastrointestinal conditions led to a significant 2.5 log difference in viability between the free (1.10 × 104 ± 1.00 × 103 cfu/mL) and the microencapsulated (5.50 × 106 ± 1.00 × 105 cfu/mL) L. fermentum NCIMB 5221 following exposure. The work presented here suggests that APA microencapsulation can be used as an effective oral delivery method for L. fermentum NCIMB 5221, a FAE-active probiotic strain.

  10. Effects of juvenile hormone (JH) analog insecticides on larval development and JH esterase activity in two spodopterans.

    Science.gov (United States)

    El-Sheikh, El-Sayed A; Kamita, Shizuo G; Hammock, Bruce D

    2016-03-01

    Juvenile hormone analog (JHA) insecticides are biological and structural mimics of JH, a key insect developmental hormone. Toxic and anti-developmental effects of the JHA insecticides methoprene, fenoxycarb, and pyriproxyfen were investigated on the larval and pupal stages of Spodoptera littoralis and Spodoptera frugiperda. Bioassays showed that fenoxycarb has the highest toxicity and fastest speed of kill in 2nd instar S. littoralis. All three JHAs affected the development of 6th instar (i.e., final instar) and pupal S. frugiperda. JH esterase (JHE) is a critical enzyme that helps to regulate JH levels during insect development. JHE activity in the last instar S. littoralis and S. frugiperda was 11 and 23 nmol min(-1) ml(-1) hemolymph, respectively. Methoprene and pyriproxyfen showed poor inhibition of JHE activity from these insects, whereas fenoxycarb showed stronger inhibition. The inhibitory activity of fenoxycarb, however, was more than 1000-fold lower than that of OTFP, a highly potent inhibitor of JHEs. Surprisingly, topical application of methoprene, fenoxycarb or pyriproxyfen on 6th instars of S. littoralis and S. frugiperda prevented the dramatic reduction in JHE activity that was found in control insects. Our findings suggest that JHAs may function as JH agonists that play a disruptive role or a hormonal replacement role in S. littoralis and S. frugiperda. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Interactions of p-Nitrobenzene Diazonium Fluoroborate and Analogs with the Active Sites of Acetylcholine-Receptor and -Esterase*

    Science.gov (United States)

    Mautner, Henry G.; Bartels, Eva

    1970-01-01

    p-Nitrobenzene diazonium fluoroborate (NDF) is a potent inhibitor of the carbamylcholine-induced depolarization of the electroplax and of acetylcholinesterase. It probably forms covalent bonds with the acetylcholine-receptor and -esterase at the active site of the proteins. Its inhibitory strength is at least the same as that of trimethylammonium diazonium fluoroborate (TDF). The p-acetoxy analog, with its weaker electron-withdrawing group, is about ten times weaker as an inhibitor than the trimethylammonium or p-nitro analogs, both of which have strong electron-withdrawing groups. After treatment of the electroplax preparation with dithiothreitol, NDF remains an irreversible receptor-inhibitor, while TDF becomes a potent reversible receptor-activator. TDF is self-inhibitory: applied before reduction, it no longer depolarizes. Although the first observations on TDF suggested that the compound labels both proteins by virtue of the steric complementary of its trimethylammonium group to a negative subsite in the proteins, the present study indicates that it is the positively charged diazonium group that reacts with the active sites of the proteins to form a covalent bond with an appropriate amino-acid residue. PMID:5272331

  12. Esterase reactions in acute myelomonocytic leukemia.

    Science.gov (United States)

    Kass, L

    1977-05-01

    Specific and nonspecific esterase reactions of bone marrow cells from 14 patients with untreated acute myelomonocytic leukemia and six patients with acute histiomonocytic leukemia were examined. The technic for esterase determination permitted simultaneous visualization of both esterases on the same glass coverslip containing the marrow cells. In cases of acute histiomonocytic leukemia, monocytes, monocytoid hemohistioblasts and undifferentiated blasts stained intensely positive for nonspecific esterase, using alpha-naphthyl acetate as the substrate. No evidence of specific esterase activity using naphthol ASD-chloroacetate as the substrate and fast blue BBN as the dye coupler was apparent in these cells. In all of the cases of acute myelomonocytic leukemia, both specific and nonspecific esterases were visualized within monocytes, monocytoid cells, and granulocytic cells that had monocytoid-type nuclei. Nonspecific esterase activity was not observed in polymorphonuclear leukocytes in cases of myelomonocytic leukemia. The results support a current viewpoint that acute myelomonocytic leukemia may be a variant of acute myeloblastic leukemia, and that cytochemically, many of the leukemic cells in myelomonocytic leukemia share properties of both granulocytes and monocytes.

  13. Selective Activation of N,N'-Diacyl Rhodamine Pro-fluorophores Paired with Releasing Enzyme, Porcine Liver Esterase (PLE).

    Science.gov (United States)

    Abney, Kristopher K; Ramos-Hunter, Susan J; Romaine, Ian M; Godwin, J Shawn; Sulikowski, Gary A; Weaver, Charles David

    2018-04-21

    This study reports the synthesis and testing of a family of rhodamine pro-fluorophores and an enzyme capable of converting pro-fluorophores to Rhodamine 110. We prepared a library of simple N,N'-diacyl rhodamines and investigated Porcine Liver Esterase (PLE) as an enzyme to activate rhodamine-based pro-fluorophores. A PLE-expressing cell line generated an increase in fluorescence rapidly upon pro-fluorophore addition demonstrating the rhodamine pro-fluorophores are readily taken up and fluorescent upon PLE-mediated release. Rhodamine pro-fluorophore amides trifluoroacetamide (TFAm) and proponamide (PAm) appeared to be the best substrates using a cell-based assay using PLE expressing HEK293. Our pro-fluorophore series showed diffusion into live cells and resisted endogenous hydrolysis. The use of our engineered cell line containing the exogenous enzyme PLE demonstrated the rigorousness of amide masking when compared to cells not containing PLE. This simple and selective pro-fluorophore rhodamine pair with PLE offers the potential to be used in vitro and in vivo fluorescence based assays. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Characterization and purification of a bacterial chlorogenic acid esterase detected during the extraction of chlorogenic acid from arbuscular mycorrhizal tomato roots.

    Science.gov (United States)

    Negrel, Jonathan; Javelle, Francine; Morandi, Dominique; Lucchi, Géraldine

    2016-12-01

    A Gram-negative bacterium able to grow using chlorogenic acid (5-caffeoylquinic acid) as sole carbon source has been isolated from the roots of tomato plants inoculated with the arbuscular mycorrhizal fungus Rhizophagus irregularis. An intracellular esterase exhibiting very high affinity (K m  = 2 μM) for chlorogenic acid has been extracted and purified by FPLC from the chlorogenate-grown cultures of this bacterium. The molecular mass of the purified esterase determined by SDS-PAGE was 61 kDa and its isoelectric point determined by chromatofocusing was 7.75. The esterase hydrolysed chlorogenic acid analogues (caffeoylshikimate, and the 4- and 3-caffeoylquinic acid isomers), feruloyl esterases substrates (methyl caffeate and methyl ferulate), and even caffeoyl-CoA in vitro but all of them were less active than chlorogenic acid, demonstrating that the esterase is a genuine chlorogenic acid esterase. It was also induced when the bacterial strain was cultured in the presence of hydroxycinnamic acids (caffeic, p-coumaric or ferulic acid) as sole carbon source, but not in the presence of simple phenolics such as catechol or protocatechuic acid, nor in the presence of organic acids such as succinic or quinic acids. The purified esterase was remarkably stable in the presence of methanol, rapid formation of methyl caffeate occurring when its activity was measured in aqueous solutions containing 10-60% methanol. Our results therefore show that this bacterial chlorogenase can catalyse the transesterification reaction previously detected during the methanolic extraction of chlorogenic acid from arbuscular mycorrhizal tomato roots. Data are presented suggesting that colonisation by Rhizophagus irregularis could increase chlorogenic acid exudation from tomato roots, especially in nutrient-deprived plants, and thus favour the growth of chlorogenate-metabolizing bacteria on the root surface or in the mycorhizosphere. Copyright © 2016 Elsevier Masson SAS. All rights

  15. Functional characterisation of a metagenome derived family VIII esterase with a deacetylation activity on ß-lactam antibiotics

    CSIR Research Space (South Africa)

    Mokoena, N

    2013-08-01

    Full Text Available characterisation of a novel esterase (Est22) derived from an acidic Leachate environment. The enzyme is 423 amino acids in length and contained 22aa signal peptide. Analysis of the Est22 primary structure revealed the presence of N-terminus S-x-x-K sequence, which...

  16. Non-specific esterases in partly mineralized bovine enamel

    DEFF Research Database (Denmark)

    Moe, D; Kirkeby, S

    1990-01-01

    Activity for non-specific esterase was demonstrated in the matrix of developing bovine enamel with alpha-naphthyl acetate and 5-bromoindoxyl acetate as the esterase substrates. By use of high-performance liquid chromatography gel filtration, ion-exchange chromatography, and electrophoresis three...... esterases were shown to be present in the enamel matrix. The enzymes showed highest activity at pH 6.5-7.5. In sections a strong reaction was observed in the secretory ameloblasts. The esterases may be proteolytic enzymes that participate in the degradation of the matrix proteins....

  17. Evaluation, partial characterization and purification of acetylcholine esterase enzyme and antiangiogenic activity from marine sponges

    Directory of Open Access Journals (Sweden)

    Maushmi Shailesh Kumar

    2014-11-01

    Full Text Available Objective: To test three marine sponges Halichondria glabrata Keller, 1891; Spirastrella pachyspira (S. pachyspira Levi, 1958 and Cliona lobata Hancock, 1849 for the presence of the acetylcholinesterase (AChE in both young and developed samples from western coastal area of India. S. pachyspira methanolic extract was selected for anti/pro angiogenic activity. Methods: They were evaluated for AChE activity using Ellman’s assay based on production of yellow colored 5-thio-2-nitrobenzoate. Purification of the enzyme was planned using ammonium sulphate precipitation and characterization by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Chorioallantoic membrane (ChAM assay model was used for angiogenic/ antiangiogenic testing. Results: All the three sponges showed good specific enzyme activity and S. pachyspira contained maximum specific enzyme activity. Sixty percent of ammonium sulphate precipitation of crude protein sample gave single band at 66 kDa corresponding to the true AChE. ChAM assay was performed at 62.5, 125.0 and 250.0 µg/mL. Dosage beyond 250 µg/mL extract showed toxic response with anti angiogenic activity at all the concentrations. Conclusions: AChE activity was detected in all samples. Extract showed good anti-angiogenic response at 62.5 µg/mL. Extract was highly toxic affecting microvasculature of ChAM as well as normal growth and development of the embryo at 500 µg/mL. With further characterization of bioactive compounds from the extract of S. pachyspira, the compounds can be developed for anti tumor activity.

  18. Determination of esterase activity and characterization of cholinesterases in the reef fish Haemulon plumieri.

    Science.gov (United States)

    Leticia, Alpuche-Gual; Gerardo, Gold-Bouchot

    2008-11-01

    White grunt (Haemulon plumieri) has been proposed by the Mesoamerican Barrier Reef System (MBRS) Synoptic Monitoring Program as a bioindicator species. It is in this sense that the present study has a main goal to evaluate this organism's suitability as an indicator species. Individuals were captured during three seasons at the port of Sisal, Yucatan, Mexico which is located in an area that is considered to be weakly impacted by human activities such as agriculture or industry. Both cholinesterase (ChE) and carboxylesterase (CbE) activities were measured in brain, muscle, liver and eye of sampled individuals. Results indicated that ChE and CbE activities were greatest in the brain (256.3 ± 43) and in the liver (191 ± 21), respectively. Furthermore, ChEs detected in brain, liver and muscle were characterized, and results suggested that the acetylcholinesterase (AChE) type was more abundant relative to pseudocholinesterase (BChE) which was rare. In addition, K(m) and V(max) and IC(50) values were calculated from the Michaelis-Menten equation. Finally, an additional experiment in vitro showed a significant decrease in both ChE and CbE activities when different tissues were exposed to model xenobiotics, such as benzo[a]pyrene and Chlorpyrifos. In conclusion, findings from this study confirm the potential suitability of H. plumieri as an organic pollution bioindicator species, and thus of practical use for environmental biomonitoring purposes.

  19. Expanding the feruloyl esterase gene family of Aspergillus niger by characterization of a feruloyl esterase, FaeC.

    Science.gov (United States)

    Dilokpimol, Adiphol; Mäkelä, Miia R; Mansouri, Sadegh; Belova, Olga; Waterstraat, Martin; Bunzel, Mirko; de Vries, Ronald P; Hildén, Kristiina S

    2017-07-25

    A feruloyl esterase (FAE) from Aspergillus niger N402, FaeC was heterologously produced in Pichia pastoris X-33 in a yield of 10mg/L. FaeC was most active at pH 7.0 and 50°C, and showed broad substrate specificity and catalyzed the hydrolysis of methyl 3,4-dimethoxycinnamate, ethyl ferulate, methyl ferulate, methyl p-coumarate, ethyl coumarate, methyl sinapate, and methyl caffeate. The enzyme released both ferulic acid and p-coumaric acid from wheat arabinoxylan and sugar beet pectin (up to 3mg/g polysaccharide), and acted synergistically with a commercial xylanase increasing the release of ferulic acid up to six-fold. The expression of faeC increased over time in the presence of feruloylated polysaccharides. Cinnamic, syringic, caffeic, vanillic and ferulic acid induced the expression of faeC. Overall expression of faeC was very low in all tested conditions, compared to two other A. niger FAE encoding genes, faeA and faeB. Our data showed that the fae genes responded differently towards the feruloylated polysaccharides and tested monomeric phenolic compounds suggesting that the corresponding FAE isoenzymes may target different substrates in a complementary manner. This may increase the efficiency of the degradation of diverse plant biomass. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Novel recombinant ethyl ferulate esterase from Burkholderia multivorans

    CSIR Research Space (South Africa)

    Rashamuse, KJ

    2007-11-01

    Full Text Available Isolation and identification of bacterial isolates with specific ferulic acid (FA) esterase activity and cloning of a gene encoding activity. A micro-organism with ethyl ferulate hydrolysing (EFH) activity was isolated by culture enrichment...

  1. Trans-methylation reactions in plants: focus on the activated methyl cycle.

    Science.gov (United States)

    Rahikainen, Moona; Alegre, Sara; Trotta, Andrea; Pascual, Jesús; Kangasjärvi, Saijaliisa

    2018-02-01

    Trans-methylation reactions are vital in basic metabolism, epigenetic regulation, RNA metabolism, and posttranslational control of protein function and therefore fundamental in determining the physiological processes in all living organisms. The plant kingdom is additionally characterized by the production of secondary metabolites that undergo specific hydroxylation, oxidation and methylation reactions to obtain a wide array of different chemical structures. Increasing research efforts have started to reveal the enzymatic pathways underlying the biosynthesis of complex metabolites in plants. Further engineering of these enzymatic machineries offers significant possibilities in the development of bio-based technologies, but necessitates deep understanding of their potential metabolic and regulatory interactions. Trans-methylation reactions are tightly coupled with the so-called activated methyl cycle (AMC), an essential metabolic circuit that maintains the trans-methylation capacity in all living cells. Tight regulation of the AMC is crucial in ensuring accurate trans-methylation reactions in different subcellular compartments, cell types, developmental stages and environmental conditions. This review addresses the organization and posttranslational regulation of the AMC and elaborates its critical role in determining metabolic regulation through modulation of methyl utilization in stress-exposed plants. © 2017 Scandinavian Plant Physiology Society.

  2. Mercury methylation and bacterial activity associated to tropical phytoplankton

    International Nuclear Information System (INIS)

    Coelho-Souza, Sergio A.; Guimaraes, Jean R.D.; Mauro, Jane B.N.; Miranda, Marcio R.; Azevedo, Sandra M.F.O.

    2006-01-01

    The methylated form of mercury (Hg), methylmercury (MeHg), is one of the most toxic pollutants. Biotic and/or abiotic methylation, often associated to sulfate-reducing bacteria metabolism, occurs in aquatic environments and in many tropical areas, mostly in the periphyton associated to floating macrophyte roots. Data about mercury methylation by phytoplankton are scarce and the aim of this study was to verify the biotic influence in the methylation process in Microcystis aeruginosa and Sineccocystis sp. laboratory strains and in natural populations of phytoplankton from two different aquatic systems, the mesotrophic Ribeirao das Lajes reservoir and hypereutrophic oligohaline Jacarepagua lagoon, Rio de Janeiro state, Brazil. Adapted radiochemical techniques were used to measure sulfate-reduction, mercury methylation and bacterial activity in phytoplankton samples. Methyl- 203 Hg formation from added inorganic 203 Hg and 3 H-Leucine uptake were measured by liquid scintillation as well as sulfate-reduction, estimated as H 2 35 S produced from added Na 2 35 SO 4 . There was no significant difference in low methylation potentials (0.37%) among the two cyanobacterium species studied in laboratory conditions. At Ribeirao das Lajes reservoir, there was no significant difference in methylation, bacterial activity and sulfate-reduction of surface sediment between the sampling points. Methylation in sediments (3-4%) was higher than in phytoplankton (1.5%), the opposite being true for bacterial activity (sediment mean 6.6 against 150.3 nmol gdw -1 h -1 for phytoplankton samples). At Jacarepagua lagoon, an expressive bacterial activity (477.1 x 10 3 nmol gdw -1 h -1 at a concentration of 1000 nM leucine) and sulfate-reduction (∼21% H 2 35 S trapped) associated to phytoplankton (mostly cyanobacteria M. aeruginosa) was observed, but mercury methylation was not detected

  3. Mercury methylation and bacterial activity associated to tropical phytoplankton

    Energy Technology Data Exchange (ETDEWEB)

    Coelho-Souza, Sergio A. [Laboratorio de Tracadores Wolfgang Pfeiffer, SL 62, Instituto de Biofisica Carlos Chagas Filho, Bloco G, Ilha do Fundao, Universidade Federal do Rio de Janeiro (IBCCF/UFRJ), RJ, CEP 21949-900 (Brazil); Guimaraes, Jean R.D. [Laboratorio de Tracadores Wolfgang Pfeiffer, SL 62, Instituto de Biofisica Carlos Chagas Filho, Bloco G, Ilha do Fundao, Universidade Federal do Rio de Janeiro (IBCCF/UFRJ), RJ, CEP 21949-900 (Brazil)]. E-mail: jeanrdg@biof.ufrj.br; Mauro, Jane B.N. [Laboratorio de Tracadores Wolfgang Pfeiffer, SL 62, Instituto de Biofisica Carlos Chagas Filho, Bloco G, Ilha do Fundao, Universidade Federal do Rio de Janeiro (IBCCF/UFRJ), RJ, CEP 21949-900 (Brazil); Miranda, Marcio R. [Laboratorio de Tracadores Wolfgang Pfeiffer, SL 62, Instituto de Biofisica Carlos Chagas Filho, Bloco G, Ilha do Fundao, Universidade Federal do Rio de Janeiro (IBCCF/UFRJ), RJ, CEP 21949-900 (Brazil); Azevedo, Sandra M.F.O. [Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, IBCCF/UFRJ, RJ (Brazil)

    2006-07-01

    The methylated form of mercury (Hg), methylmercury (MeHg), is one of the most toxic pollutants. Biotic and/or abiotic methylation, often associated to sulfate-reducing bacteria metabolism, occurs in aquatic environments and in many tropical areas, mostly in the periphyton associated to floating macrophyte roots. Data about mercury methylation by phytoplankton are scarce and the aim of this study was to verify the biotic influence in the methylation process in Microcystis aeruginosa and Sineccocystis sp. laboratory strains and in natural populations of phytoplankton from two different aquatic systems, the mesotrophic Ribeirao das Lajes reservoir and hypereutrophic oligohaline Jacarepagua lagoon, Rio de Janeiro state, Brazil. Adapted radiochemical techniques were used to measure sulfate-reduction, mercury methylation and bacterial activity in phytoplankton samples. Methyl-{sup 203}Hg formation from added inorganic {sup 203}Hg and {sup 3}H-Leucine uptake were measured by liquid scintillation as well as sulfate-reduction, estimated as H{sub 2} {sup 35}S produced from added Na{sub 2} {sup 35}SO{sub 4}. There was no significant difference in low methylation potentials (0.37%) among the two cyanobacterium species studied in laboratory conditions. At Ribeirao das Lajes reservoir, there was no significant difference in methylation, bacterial activity and sulfate-reduction of surface sediment between the sampling points. Methylation in sediments (3-4%) was higher than in phytoplankton (1.5%), the opposite being true for bacterial activity (sediment mean 6.6 against 150.3 nmol gdw{sup -1} h{sup -1} for phytoplankton samples). At Jacarepagua lagoon, an expressive bacterial activity (477.1 x 10{sup 3} nmol gdw{sup -1} h{sup -1} at a concentration of 1000 nM leucine) and sulfate-reduction ({approx}21% H{sub 2} {sup 35}S trapped) associated to phytoplankton (mostly cyanobacteria M. aeruginosa) was observed, but mercury methylation was not detected.

  4. Purification and characterization of a type B feruloyl esterase (StFAE-A) from the thermophilic fungus Sporotrichum thermophile

    DEFF Research Database (Denmark)

    Topakas, E.; Stamatis, H.; Biely, P.

    2004-01-01

    A feruloyl esterase (StFAE-A) produced by Sporotrichum thermophile was purified to homogeneity. The purified homogeneous preparation of native StFAE-A exhibited a molecular mass of 57.0+/-1.5 kDa, with a mass of 33+/-1 kDa on SDS-PAGE. The pI of the enzyme was estimated by cation......-exchange chromatofocusing to be at pH 3.1. The enzyme activity was optimal at pH 6.0 and 55-60 degreesC. The purified esterase was stable at the pH range 5.0-7.0. The enzyme retained 70% of activity after 7 h at 50 degreesC and lost 50% of its activity after 45 min at 55 degreesC and after 12 min at 60 degrees......C. Determination of k(cat)/K-m revealed that the enzyme hydrolyzed methyl p-coumarate 2.5- and 12-fold more efficiently than methyl caffeate and methyl ferulate, respectively. No activity on methyl sinapinate was detected. The enzyme was active on substrates containing ferulic acid ester linked to the C-5 and C-2...

  5. The structure of a novel thermophilic esterase from the Planctomycetes species, Thermogutta terrifontis reveals an open active site due to a minimal ‘cap’ domain.

    Directory of Open Access Journals (Sweden)

    Jennifer Ann Littlechild

    2015-11-01

    Full Text Available A carboxyl esterase (TtEst2 has been identified in a novel thermophilic bacterium, Thermogutta terrifontis from the phylum Planctomycetes and has been cloned and over-expressed in Escherichia coli. The enzyme has been characterised biochemically and shown to have activity towards small p-nitrophenyl (pNP carboxylic esters with optimal activity for pNP-acetate. The enzyme shows moderate thermostability retaining 75% activity after incubation for 30 minutes at 70°C. The crystal structures have been determined for the native TtEst2 and its complexes with the carboxylic acid products propionate, butyrate and valerate. TtEst2 differs from most enzymes of the α/β-hydrolase family 3 as it lacks the majority of the ‘cap’ domain and its active site cavity is exposed to the solvent. The bound ligands have allowed the identification of the carboxyl pocket in the enzyme active site. Comparison of TtEst2 with structurally related enzymes has given insight into how differences in their substrate preference can be rationalised based upon the properties of their active site pockets.

  6. The effect of increased yeast alcohol acetyltransferase and esterase activity on the flavour profiles of wine and distillates.

    Science.gov (United States)

    Lilly, Mariska; Bauer, Florian F; Lambrechts, Marius G; Swiegers, Jan H; Cozzolino, Daniel; Pretorius, Isak S

    2006-07-15

    The fruity odours of wine are largely derived from the synthesis of esters and higher alcohols during yeast fermentation. The ATF1- and ATF2-encoded alcohol acetyltransferases of S. cerevisiae are responsible for the synthesis of ethyl acetate and isoamyl acetate esters, while the EHT1-encoded ethanol hexanoyl transferase is responsible for synthesizing ethyl caproate. However, esters such as these might be degraded by the IAH1-encoded esterase. The objectives of this study were: (a) to overexpress the genes encoding ester-synthesizing and ester-degrading enzymes in wine yeast; (b) to prepare Colombard table wines and base wines for distillation using these modified strains; and (c) to analyse and compare the ester concentrations and aroma profiles of these wines and distillates. The overexpression of ATF1 significantly increased the concentrations of ethyl acetate, isoamyl acetate, 2-phenylethyl acetate and ethyl caproate, while the overexpression of ATF2 affected the concentrations of ethyl acetate and isoamyl acetate to a lesser degree. The overexpression of IAH1 resulted in a significant decrease in ethyl acetate, isoamyl acetate, hexyl acetate and 2-phenylethyl acetate. The overexpression of EHT1 resulted in a marked increase in ethyl caproate, ethyl caprylate and ethyl caprate. The flavour profile of the wines and distillates prepared using the modified strains were also significantly altered as indicated by formal sensory analysis. This study offers prospects for the development of wine yeast starter strains with optimized ester-producing capability that could assist winemakers in their effort to consistently produce wine and distillates such as brandy to definable flavour specifications and styles.

  7. Lactobacillus fermentum CRL1446 Ameliorates Oxidative and Metabolic Parameters by Increasing Intestinal Feruloyl Esterase Activity and Modulating Microbiota in Caloric-Restricted Mice

    Directory of Open Access Journals (Sweden)

    Matias Russo

    2016-07-01

    Full Text Available The purpose of this study was to determine whether the administration of the feruloyl esterase (FE-producing strain Lactobacillus fermentum CRL1446 enhances metabolic and oxidative parameters in caloric-restricted (CR mice. Balb/c male mice were divided into ad libitum fed Group (ALF Group, CR diet Group (CR Group and CR diet plus L. fermentum Group (CR-Lf Group. CR diet was administered during 45 days and CRL1446 strain was given in the dose of 108 cells/mL/day/mouse. FE activity was determined in intestinal mucosa and content at Day 1, 20 and 45. Triglyceride, total cholesterol, glucose, thiobarbituric acid reactive substances (TBARS levels and glutathione reductase activity were determined in plasma. Gut microbiota was evaluated by high-throughput sequencing of 16S rRNA gene amplicons. At Day 45, total intestinal FE activity in CR-Lf Group was higher (p = 0.020 than in CR and ALF groups and an improvement in both metabolic (reductions in triglyceride (p = 0.0025, total cholesterol (p = 0.005 and glucose (p < 0.0001 levels and oxidative (decrease of TBARS levels and increase of plasmatic glutathione reductase activity (p = 0.006 parameters was observed, compared to ALF Group. CR diet increased abundance of Bacteroidetes and CRL1446 administration increased abundance of Bifidobacterium and Lactobacillus genus. L. fermentun CRL1446 exerted a bifidogenic effect under CR conditions.

  8. Carbonic anhydrase (acetazolamide-sensitive esterase) activity in the blood, gill and kidney of the thermally acclimated rainbow trout, Salmo gairdneri

    Energy Technology Data Exchange (ETDEWEB)

    Houston, A.H.; McCarty, L.S.

    1978-04-01

    Gill, kidney and blood levels of acetazolamide-sensitive esterase (carbonic anhydrase) activity were estimated at acclimation temperature and at a common temperature (25/sup 0/C) in rainbow trout acclimated to 2, 10, and 18/sup 0/C. Plasma levels of sodium, potassium and chloride were also examined for possible acclimatory variations. Plasma sodium and chloride levels, and the sodium:chloride ratio were unaffected by thermal acclimation; potassium concentrations were significantly elevated at 18/sup 0/C. Significant, but modest changes in renal and branchial carbonic anhydrase activity were observed under physiologically realistic incubation temperature conditions. Blood carbonic anhydrase activity was sharply elevated at higher acclimation temperatures. The data are discussed in relation to the hypothesis that carbonic anhydrase in this relatively stenothermal freshwater salmonid, through its intimate association with the coupled HCO/sub 3//sup -//Cl/sup -/ and H/sup +/ + NH/sub 4//sup +//Na/sup +/ exchange systems may provide for relatively thermostable basal rates of sodium and chloride uptake from the medium and recovery from urine. The renal, and more notably the branchial (Na/sup +//K/sup +/)-simulated ATPase systems, and erythrocytic carbonic anhydrase may then serve primarily as high-temperature amplifiers of sodium and chloride recruitment respectively.

  9. B-esterase activities and blood cell morphology in the frog Leptodactylus chaquensis (Amphibia: Leptodactylidae) on rice agroecosystems from Santa Fe Province (Argentina).

    Science.gov (United States)

    Attademo, Andrés M; Cabagna-Zenklusen, Mariana; Lajmanovich, Rafael C; Peltzer, Paola M; Junges, Celina; Bassó, Agustín

    2011-01-01

    Activity of B-esterases (BChE: butyrylcholinesterase and CbE: carboxylesterase using two model substrates: α-naphthyl acetate and 4-nitrophenyl valerate) in a native frog, Leptodactylus chaquensis from rice fields (RF1: methamidophos and RF2: cypermethrin and endosulfan sprayed by aircraft) and non-contaminated area (pristine forest) was measured. The ability of pyridine-2-aldoxime methochloride (2-PAM) to reactivate BChE levels was also explored. In addition, changes in blood cell morphology and parasite infection were determined. Mean values of plasma BChE activities were lower in samples from the two rice fields than in those from the reference site. CbE (4-nitrophenyl valerate) levels varied in the three sites studied, being highest in RF1. Frog plasma from RF1 showed positive reactivation of BChE activity after incubation with 2-PAM. Blood parameters of frogs from RF2 revealed morphological alterations (anisochromasia and immature erythrocytes frequency). Moreover, a major infection of protozoan Trypanosoma sp. in individuals from the two rice fields was detected. We suggest that integrated use of several biomarkers (BChE and CBEs, chemical reactivation of plasma with 2-PAM, and blood cell parameters) may be a promising procedure for use in biomonitoring programmes to diagnose pesticide exposure of wild populations of this frog and other native anuran species in Argentina.

  10. A Method for Fast Assessment of OP/CB Exposure in the Japanese Quail (Coturnix coturnix japonica Using Combined Esterases Enzyme Activity as Biomarkers

    Directory of Open Access Journals (Sweden)

    Kasim Sakran Abass

    2014-01-01

    Full Text Available The aims of this study were to investigate the presence of different esterase activities in plasma and liver for Japanese quail and to combine determination of both carboxylesterase and cholinesterase as biochemical biomarker in order to identify the effects of carbamate and organophosphate compounds exposure. Carboxylesterase exhibits larger sensitivity to carbamate and organophosphate compounds than to cholinesterase and is present at higher levels. This permitted nature and distribution of carboxylesterase or cholinesterase to be measured. One predominant toxicological form of enzyme level constant in its patterns of motivation and inhibition with cholinesterase was identified in plasma with an apparent Michaelis constant for butyrylthiocholine iodide of 0.394 mM. Carboxylesterase activity in liver was considered by its preferential hydrolysis of the S-phenyl thioacetate. A concentration dependent decrease of carboxylesterase and cholinesterase has demonstrated during in vitro incubation of malathion, parathion, and trichlorfon in the range 0.125–2 mM, while with methomyl was in the range 0.25–4 mM. When quail (n=15 was exposed orally for 48 h to concentrations of carbamate or organophosphate compounds of 3–200 mg/kg, the percentage inhibition of cholinesterase was in each case larger than that of carboxylesterase and reached statistical significance (P<0.05 at lower concentrations.

  11. Mercuric chloride-induced alterations of levels of noradrenaline, dopamine, serotonin and acetylcholine esterase activity in different regions of rat brain during postnatal development

    Energy Technology Data Exchange (ETDEWEB)

    Lakshmana, M.K. (Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bangalore (India)); Desiraju, T. (Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bangalore (India)); Raju, T.R. (Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Bangalore (India))

    1993-07-01

    Wistar rats were fed mercuric chloride, 4 mg/kg body weight per day chronically from postnatal day 2 to 60 by gastric intubation. Mercury consumption was then discontinued until 170 days to allow time for recovery. Since mercury caused reduction in body weight, an underweight group was also included besides the normal saline group. Levels of noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT) and the activity of acetylcholine esterase (AChE) were assayed in various brain regions in different age groups. By 60 days of age, the mercury group showed elevations of NA levels in olfactory bulb (OB), visual cortex (VC) and brain stem (BS) but not in striatumaccumbens (SA) and hippocampus (HI). DA levels were also increased in OB, HI, VC and BS but not in SA. AChE activity was decreased in the mercury group only in HI and VC at 20 days of age. The Mercury group showed no behavioural abnormality outwardly; however, operant conditioning relevated a dificiency in performance. Nevertheless, all these changes disappeared after discontinuation of mercury intake. Thus the changes occurring in the brain at this level of oral mercuric chloride intake seem to reflect adaptive neural mechanisms rather than pathological damage. (orig.)

  12. Characterisation of a New Family of Carboxyl Esterases with an OsmC Domain.

    Directory of Open Access Journals (Sweden)

    Mai-Britt V Jensen

    Full Text Available Proteins in the serine esterase family are widely distributed in bacterial phyla and display activity against a range of biologically produced and chemically synthesized esters. A serine esterase from the psychrophilic bacterium Pseudoalteromonas arctica with a C-terminal OsmC-like domain was recently characterized; here we report on the identification and characterization of further putative esterases with OsmC-like domains constituting a new esterase family that is found in a variety of bacterial species from different environmental niches. All of these proteins contained the Ser-Asp-His motif common to serine esterases and a highly conserved pentapeptide nucleophilic elbow motif. We produced these proteins heterologously in Escherichia coli and demonstrated their activity against a range of esterase substrates. Two of the esterases characterized have activity of over two orders of magnitude higher than other members of the family, and are active over a wide temperature range. We determined the crystal structure of the esterase domain of the protein from Rhodothermus marinus and show that it conforms to the classical α/β hydrolase fold with an extended 'lid' region, which occludes the active site of the protein in the crystal. The expansion of characterized members of the esterase family and demonstration of activity over a wide-range of temperatures could be of use in biotechnological applications such as the pharmaceutical, detergent, bioremediation and dairy industries.

  13. Fungal glucuronoyl esterases : Genome mining based enzyme discovery and biochemical characterization

    NARCIS (Netherlands)

    Dilokpimol, Adiphol; Mäkelä, Miia R; Cerullo, Gabriella; Zhou, Miaomiao; Varriale, Simona; Gidijala, Loknath; Brás, Joana L A; Jütten, Peter; Piechot, Alexander; Verhaert, Raymond; Faraco, Vincenza; Hilden, Kristiina S.; de Vries, Ronald P

    2018-01-01

    4-O-Methyl-d-glucuronic acid (MeGlcA) is a side-residue of glucuronoarabinoxylan and can form ester linkages to lignin, contributing significantly to the strength and rigidity of the plant cell wall. Glucuronoyl esterases (4-O-methyl-glucuronoyl methylesterases, GEs) can cleave this ester bond, and

  14. Studies of the Interaction between Isoimperatorin and Human Serum Albumin by Multispectroscopic Method: Identification of Possible Binding Site of the Compound Using Esterase Activity of the Protein

    Directory of Open Access Journals (Sweden)

    Samira Ranjbar

    2013-01-01

    Full Text Available Isoimperatorin is one of the main components of Prangos ferulacea as a linear furanocoumarin and used as anti-inflammatory, analgesic, antispasmodic, and anticancer drug. Human serum albumin (HSA is a principal extracellular protein with a high concentration in blood plasma and carrier for many drugs to different molecular targets. Since the carrying of drug by HSA may affect on its structure and action, we decided to investigate the interaction between HSA and isoimperatorin using fluorescence and UV spectroscopy. Fluorescence data indicated that isoimperatorin quenches the intrinsic fluorescence of the HSA via a static mechanism and hydrophobic interaction play the major role in the drug binding. The binding average distance between isoimperatorin and Trp 214 of HSA was estimated on the basis of the theory of Förster energy transfer. Decrease of protein surface hydrophobicity (PSH was also documented upon isoimperatorin binding. Furthermore, the synchronous fluorescence spectra show that the microenvironment of the tryptophan residues does not have obvious changes. Site marker compettive and fluorescence experiments revealed that the binding of isoimperatorin to HSA occurred at or near site I. Finally, the binding details between isoimperatorin and HSA were further confirmed by molecular docking and esterase activity inhibition studies which revealed that drug was bound at subdomain IIA.

  15. Synthesis of a tritiated herbicide with high activity: methyl thifensulfuron

    International Nuclear Information System (INIS)

    Bastide, J.; Ortega, F.

    1993-01-01

    In order to study the binding on acetolactate synthase, a tritiated herbicide sulfonylurea (thifensulfuron methyl) of high specific activity was synthesized. By use of C 3 H 3 I for esterification of an acid group, a rapid incorporation of tritium into this compound may be achieved. (Author)

  16. Functional and structural characterization of a thermostable acetyl esterase from Thermotoga maritima

    NARCIS (Netherlands)

    Levisson, M.; Han, G.W.; Deller, M.C.; Hendriks, S.N.A.; Oost, van der J.; Kengen, S.W.M.

    2012-01-01

    TM0077 from Thermotoga maritima is a member of the carbohydrate esterase family 7 and is active on a variety of acetylated compounds, including cephalosporin C. TM0077 esterase activity is confined to short-chain acyl esters (C2-C3), and is optimal around 100°C and pH 7.5. The positional specificity

  17. Histochemical studies on genetical control of hormonal enzyme inducibility in the mouse. I. Non-specific esterase activity and regional histology of the epididymis

    DEFF Research Database (Denmark)

    Blecher, S R; Kirkeby, S

    1978-01-01

    As a base line for future cell genetical studies the authors record the distribution of non-specific esterase reaction in the various histologically distinguishable cell types of the mouse epididymis. The findings are correlated with previous descriptions of the lobar structure of the organ...

  18. Switching catalysis from hydrolysis to perhydrolysis in P. fluorescens esterase

    Science.gov (United States)

    Yin, De Lu (Tyler); Bernhardt, Peter; Morley, Krista L.; Jiang, Yun; Cheeseman, Jeremy D.; Purpero, Vincent; Schrag, Joseph D.; Kazlauskas, Romas J.

    2010-01-01

    Many serine hydrolases catalyze perhydrolysis – the reversible formation of per-acids from carboxylic acids and hydrogen peroxide. Recently we showed that a single amino acid substitution in the alcohol binding pocket - L29P - in Pseudomonas fluorescens (SIK WI) aryl esterase (PFE) increased the specificity constant of PFE for peracetic acid formation >100-fold [Bernhardt et al. Angew. Chem. Intl. Ed. 2005, 44, 2742]. In this paper, we extend this work to address the three following questions. First, what is the molecular basis of the increase in perhydrolysis activity? We previously proposed that the L29P substitution creates a hydrogen bond between the enzyme and hydrogen peroxide in the transition state. Here we report two x-ray structures of L29P PFE that support this proposal. Both structures show a main chain carbonyl oxygen closer to the active-site serine as expected. One structure further shows acetate in the active site in an orientation consistent with reaction by an acyl-enzyme mechanism. We also detected an acyl-enzyme intermediate in the hydrolysis of ε-caprolactone by mass spectrometry. Second, can we further increase perhydrolysis activity? We discovered that the reverse reaction – hydrolysis of peracetic acid to acetic acid and hydrogen peroxide – occurs at nearly the diffusion limited rate. Since the reverse reaction cannot increase further, neither can the forward reaction. Consistent with this prediction, two variants with additional amino acid substitutions showed two fold higher kcat, but Km also increased so the specificity constant, kcat/Km, remained similar. Third, how does the L29P substitution change the esterase activity? Ester hydrolysis decreased for most esters (75-fold for ethyl acetate), but not for methyl esters. In contrast, L29P PFE catalyzed hydrolysis of ε-caprolactone five times more efficiently than wild-type PFE. Molecular modeling suggests that moving the carbonyl group closer to the active site blocks access for

  19. Switching Catalysis from Hydrolysis to Perhydrolysis in Pseudomonas fluorescens Esterase

    Energy Technology Data Exchange (ETDEWEB)

    Yin, D.; Bernhardt, P; Morley, K; Jiang, Y; Cheeseman, J; Purpero, V; Schrag, J; Kazlauskas, R

    2010-01-01

    Many serine hydrolases catalyze perhydrolysis, the reversible formation of peracids from carboxylic acids and hydrogen peroxide. Recently, we showed that a single amino acid substitution in the alcohol binding pocket, L29P, in Pseudomonas fluorescens (SIK WI) aryl esterase (PFE) increased the specificity constant of PFE for peracetic acid formation >100-fold [Bernhardt et al. (2005) Angew. Chem., Int. Ed. 44, 2742]. In this paper, we extend this work to address the three following questions. First, what is the molecular basis of the increase in perhydrolysis activity? We previously proposed that the L29P substitution creates a hydrogen bond between the enzyme and hydrogen peroxide in the transition state. Here we report two X-ray structures of L29P PFE that support this proposal. Both structures show a main chain carbonyl oxygen closer to the active site serine as expected. One structure further shows acetate in the active site in an orientation consistent with reaction by an acyl-enzyme mechanism. We also detected an acyl-enzyme intermediate in the hydrolysis of {var_epsilon}-caprolactone by mass spectrometry. Second, can we further increase perhydrolysis activity? We discovered that the reverse reaction, hydrolysis of peracetic acid to acetic acid and hydrogen peroxide, occurs at nearly the diffusion limited rate. Since the reverse reaction cannot increase further, neither can the forward reaction. Consistent with this prediction, two variants with additional amino acid substitutions showed 2-fold higher k{sub cat}, but K{sub m} also increased so the specificity constant, k{sub cat}/K{sub m}, remained similar. Third, how does the L29P substitution change the esterase activity? Ester hydrolysis decreased for most esters (75-fold for ethyl acetate) but not for methyl esters. In contrast, L29P PFE catalyzed hydrolysis of {var_epsilon}-caprolactone five times more efficiently than wild-type PFE. Molecular modeling suggests that moving the carbonyl group closer to the

  20. Probiotic Ferulic Acid Esterase Active Lactobacillus fermentum NCIMB 5221 APA Microcapsules for Oral Delivery: Preparation and in Vitro Characterization

    OpenAIRE

    Tomaro-Duchesneau, Catherine; Saha, Shyamali; Malhotra, Meenakshi; Coussa-Charley, Michael; Kahouli, Imen; Jones, Mitchell L.; Labb?, Alain; Prakash, Satya

    2012-01-01

    Probiotics possess potential therapeutic and preventative effects for various diseases and metabolic disorders. One important limitation for the oral delivery of probiotics is the harsh conditions of the upper gastrointestinal tract (GIT) which challenge bacterial viability and activity. One proposed method to surpass this obstacle is the use of microencapsulation to improve the delivery of bacterial cells to the lower GIT. The aim of this study is to use alginate-poly-L-lysine-alginate (APA)...

  1. [Central muscle relaxant activities of 2-methyl-3-aminopropiophenone derivatives].

    Science.gov (United States)

    Kontani, H; Mano, A; Koshiura, R; Yamazaki, M; Shimada, Y; Oshita, M; Morikawa, K; Kato, H; Ito, Y

    1987-02-01

    In this experiment, we synthetized new 2-methyl-3-aminopropiophenone (MP) derivatives, whose structure is known to have central muscle relaxant activities, and quinolizidine and indan . tetralin derivatives derived from MP by cyclization, and we investigated the central muscle relaxant activity. Among the quinolizidine derivatives, there was a very strong central depressant agent, trans (3H, 9aH)-3-(p-chloro) benzoyl-quinolizidine (HSR-740), and among the indan . tetralin derivatives, there was an excitant agents, trans (1H, 2H)-5-methoxy-3, 3-dimethyl-2-piperidinomethyl indan-1-ol (HSR-719). From the results, these derivatives were not considered to be adequate for central muscle relaxant. Among the MP derivatives, (4'-chloro-2'-methoxy-3-piperidino) propiophenone HCl (HSR-733) and (4'-ethyl-2-methyl-3-pyrrolidino) propiophenone HCl (HSR-770) strongly inhibited the cooperative movement in the rotating rod method using mice, and it exerted almost the same depressant activity on the cross extensor reflex using alpha-chloralose anesthetized rats. However, the inhibitory effects of HSR-733 on the anemic decerebrate rigidity and the rigidity induced by intracollicular decerebration in rats were weaker than those of HSR-770 and eperisone. In spinal cats, at a low dose (5 mg/kg, i.v.), HSR-733 depressed monosynaptic and dorsal root reflex potentials as compared with polysynaptic reflex potentials, and inhibitory effects of HSR-733 on these three reflex potentials were more potent than those of eperisone and HSR-770. Although HSR-770 acts on the spinal cord and supraspinal level on which eperisone has been reported to act, HSR-733 may mainly act on the spinal cord. These results indicate that the MP derivative with a 2-methyl group may be suitable as a central muscle relaxant. HSR-770, which has equipotent muscle relaxant activity to eperisone, exerted strong inhibitory effects on oxotremorine-induced tremor and weak inhibitory effects on spontaneous motor activity in the

  2. Esterase screening using whole cells of Brazilian soil microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, Simone M.; Oliveira, Luciana G. de; Marsaioli, Anita J., E-mail: anita@iqm.unicamp.b [Universidade Estadual de Campinas (IQ/UNICAMP), SP (Brazil). Inst. de Quimica

    2010-07-01

    A miniaturized enzymatic assay using fluorescent probes to reveal esterase producing microorganisms was optimized and applied to screen 64 soil bacterial strains. The best results were validated using traditional non-fluorogenic assays with acetyl and propanoyl phenylethanol to confirm the miniaturized results. The most active microorganisms belong to the genus Bacillus showing esterase activity and good enantiomeric ratios for the resolution of phenylethanol derivatives (E > 30). Part of the microorganisms are kept in our laboratory in glycerol or freezedried and the best microorganisms will be deposited in the CBMAI/CPQBA/UNICAMP culture collection. (author)

  3. On-line anti-acetylcholine esterase activity of extracts of oxystelma esculentum, aerva javanica and zanthoxylum armatum

    International Nuclear Information System (INIS)

    Murtaza, S.; Ullah, R. S.; Abbas, A.; Riaz, T.; Ghous, T.; Altaf, Y.; Khan, M.; Ahmed, S.

    2013-01-01

    Alzheimer's disease (AD), a disease of brain, resulting in memory impairment and the loss of thinking. The main reason of Alzheimer's disease is firmly associated with some impairment in cholinergic transmission. This impairment may be improved by diminishing the breakdown of acetylcholine at the synaptic site in the brain by inhibiting acetylcholinesterase (AChE). In this work, extracts of three different plants Oxystelma esculentum (OEM), Aerva javanica (AJM) and Zanthoxylum armatum (ZAA) have been screened for their anti-AchE activity. Results of the study demonstrate that of the studied extracts, ZAA (IC/sub 50/ 55.5 micro g/ml) acquired stronger anti-AChE activity. While OEM with IC/sub 50/ 107.2 micro g/ml showed moderate and ZAE and AJM showed weaker action (IC/sub 50/ 182.5 and 275.2 micro g/ml). Galanthamine was used as a positive control (IC/sub 50/ 1.47 micro g/ml). (author)

  4. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

    Science.gov (United States)

    Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

    2012-10-01

    A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

  5. Xylella fastidiosa esterase rather than hydroxynitrile lyase.

    Science.gov (United States)

    Torrelo, Guzman; Ribeiro de Souza, Fayene Zeferino; Carrilho, Emanuel; Hanefeld, Ulf

    2015-03-02

    In 2009, we reported that the product of the gene SCJ21.16 (XFa0032) from Xylella fastidiosa, a xylem-restricted plant pathogen that causes a range of diseases in several important crops, encodes a protein (XfHNL) with putative hydroxynitrile lyase activity. Sequence analysis and activity tests indicated that XfHNL exhibits an α/β-hydrolase fold and could be classified as a member of the family of FAD-independent HNLs. Here we provide a more detailed sequence analysis and new experimental data. Using pure heterologously expressed XfHNL we show that this enzyme cannot catalyse the cleavage/synthesis of mandelonitrile and that this protein is in fact a non-enantioselective esterase. Homology modelling and ligand docking simulations were used to study the active site and support these results. This finding could help elucidate the common ancestor of esterases and hydroxynitrile lyases with an α/β -hydrolase fold. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Spectroscopic study of drug-binding characteristics of unmodified and pNPA-based acetylated human serum albumin: Does esterase activity affect microenvironment of drug binding sites on the protein?

    Energy Technology Data Exchange (ETDEWEB)

    Moradi, Nastaran [Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Faculty of Pharmaceutical Sciences, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Ashrafi-Kooshk, Mohammad Reza [Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Ghobadi, Sirous [Department of Biology, Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Shahlaei, Mohsen [Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Faculty of Pharmaceutical Sciences, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Khodarahmi, Reza, E-mail: rkhodarahmi@mbrc.ac.ir [Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of); Faculty of Pharmaceutical Sciences, Kermanshah University of Medical Sciences, Kermanshah (Iran, Islamic Republic of)

    2015-04-15

    Human serum albumin (HSA) is the most prominent extracellular protein in blood plasma. There are several binding sites on the protein which provide accommodation for structurally-unrelated endogenous and exogenous ligands and a wide variety of drugs. “Esterase-like” activity (hydrolysis of p-nitrophenyl esters) by the protein has been also reported. In the current study, we set out to investigate the interaction of indomethacin and ibuprofen with the unmodified and modified HSA (pNPA-modified HSA) using various spectroscopic techniques. Fluorescence data showed that 1:1 binding of drug to HSA is associated with quenching of the protein intrinsic fluorescence. Decrease of protein surface hydrophobicity (PSH), alteration in drug binding affinity and change of the protein stability, after esterase-like activity and permanent acetylation of HSA, were also documented. Analysis of the quenching and thermodynamic parameters indicated that forces involved in drug–HSA interactions change upon the protein modification. - Highlights: • Binding propensity of indomethacin extremely decreased upon the protein acetylation. • There is no ibuprofen binding after protein acetylation. • Protein stability changes upon drug binding as well as protein acetylation. • Drug pharmacokinetics may be influenced under co-administration of HSA-modifier drugs.

  7. Spectroscopic study of drug-binding characteristics of unmodified and pNPA-based acetylated human serum albumin: Does esterase activity affect microenvironment of drug binding sites on the protein?

    International Nuclear Information System (INIS)

    Moradi, Nastaran; Ashrafi-Kooshk, Mohammad Reza; Ghobadi, Sirous; Shahlaei, Mohsen; Khodarahmi, Reza

    2015-01-01

    Human serum albumin (HSA) is the most prominent extracellular protein in blood plasma. There are several binding sites on the protein which provide accommodation for structurally-unrelated endogenous and exogenous ligands and a wide variety of drugs. “Esterase-like” activity (hydrolysis of p-nitrophenyl esters) by the protein has been also reported. In the current study, we set out to investigate the interaction of indomethacin and ibuprofen with the unmodified and modified HSA (pNPA-modified HSA) using various spectroscopic techniques. Fluorescence data showed that 1:1 binding of drug to HSA is associated with quenching of the protein intrinsic fluorescence. Decrease of protein surface hydrophobicity (PSH), alteration in drug binding affinity and change of the protein stability, after esterase-like activity and permanent acetylation of HSA, were also documented. Analysis of the quenching and thermodynamic parameters indicated that forces involved in drug–HSA interactions change upon the protein modification. - Highlights: • Binding propensity of indomethacin extremely decreased upon the protein acetylation. • There is no ibuprofen binding after protein acetylation. • Protein stability changes upon drug binding as well as protein acetylation. • Drug pharmacokinetics may be influenced under co-administration of HSA-modifier drugs

  8. The Helicase Activity of Hyperthermophilic Archaeal MCM is Enhanced at High Temperatures by Lysine Methylation.

    Science.gov (United States)

    Xia, Yisui; Niu, Yanling; Cui, Jiamin; Fu, Yang; Chen, Xiaojiang S; Lou, Huiqiang; Cao, Qinhong

    2015-01-01

    Lysine methylation and methyltransferases are widespread in the third domain of life, archaea. Nevertheless, the effects of methylation on archaeal proteins wait to be defined. Here, we report that recombinant sisMCM, an archaeal homolog of Mcm2-7 eukaryotic replicative helicase, is methylated by aKMT4 in vitro. Mono-methylation of these lysine residues occurs coincidently in the endogenous sisMCM protein purified from the hyperthermophilic Sulfolobus islandicus cells as indicated by mass spectra. The helicase activity of mini-chromosome maintenance (MCM) is stimulated by methylation, particularly at temperatures over 70°C. The methylated MCM shows optimal DNA unwinding activity after heat-treatment between 76 and 82°C, which correlates well with the typical growth temperatures of hyperthermophilic Sulfolobus. After methylation, the half life of MCM helicase is dramatically extended at 80°C. The methylated sites are located on the accessible protein surface, which might modulate the intra- and inter- molecular interactions through changing the hydrophobicity and surface charge. Furthermore, the methylation-mimic mutants of MCM show heat resistance helicase activity comparable to the methylated MCM. These data provide the biochemical evidence that posttranslational modifications such as methylation may enhance kinetic stability of proteins under the elevated growth temperatures of hyperthermophilic archaea.

  9. Expression of mung bean pectin acetyl esterase in potato tubers: effect on acetylation of cell wall polymers and tuber mechanical properties.

    Science.gov (United States)

    Orfila, Caroline; Dal Degan, Florence; Jørgensen, Bodil; Scheller, Henrik Vibe; Ray, Peter M; Ulvskov, Peter

    2012-07-01

    A mung bean (Vigna radiata) pectin acetyl esterase (CAA67728) was heterologously expressed in tubers of potato (Solanum tuberosum) under the control of the granule-bound starch synthase promoter or the patatin promoter in order to probe the significance of O-acetylation on cell wall and tissue properties. The recombinant tubers showed no apparent macroscopic phenotype. The enzyme was recovered from transgenic tubers using a high ionic strength buffer and the extract was active against a range of pectic substrates. Partial in vivo de-acetylation of cell wall polysaccharides occurred in the transformants, as shown by a 39% decrease in the degree of acetylation (DA) of tuber cell wall material (CWM). Treatment of CWM using a combination of endo-polygalacturonase and pectin methyl esterase extracted more pectin polymers from the transformed tissue compared to wild type. The largest effect of the pectin acetyl esterase (68% decrease in DA) was seen in the residue from this extraction, suggesting that the enzyme is preferentially active on acetylated pectin that is tightly bound to the cell wall. The effects of acetylation on tuber mechanical properties were investigated by tests of failure under compression and by determination of viscoelastic relaxation spectra. These tests suggested that de-acetylation resulted in a stiffer tuber tissue and a stronger cell wall matrix, as a result of changes to a rapidly relaxing viscoelastic component. These results are discussed in relation to the role of pectin acetylation in primary cell walls and its implications for industrial uses of potato fibres.

  10. Potentiation of insulin release in response to amino acid methyl esters correlates to activation of islet glutamate dehydrogenase activity

    DEFF Research Database (Denmark)

    Kofod, Hans; Lernmark, A; Hedeskov, C J

    1986-01-01

    Column perifusion of mouse pancreatic islets was used to study the ability of amino acids and their methyl esters to influence insulin release and activate islet glutamate dehydrogenase activity. In the absence of L-glutamine, L-serine and the methyl ester of L-phenylalanine, but neither L...... glutamate dehydrogenase activity showed that only the two methyl esters of L-phenylalanine and L-serine activated the enzyme. It is concluded that the mechanism by which methyl esters of amino acids potentiate insulin release is most likely to be mediated by the activation of pancreatic beta-cell glutamate...

  11. In vitro comparison of rat and chicken brain neurotoxic esterase

    International Nuclear Information System (INIS)

    Novak, R.; Padilla, S.

    1986-01-01

    A systematic comparison was undertaken to characterize neurotoxic esterase (NTE) from rat and chicken brain in terms of inhibitor sensitivities, pH optima, and molecular weights. Paraoxon titration of phenyl valerate (PV)-hydrolyzing carboxylesterases showed that rat esterases were more sensitive than chicken to paraoxon inhibition at concentrations less than or equal to microM and superimposable with chicken esterases at concentrations of 2.5-1000 microM. Mipafox titration of the paraoxon-resistant esterases at a fixed paraoxon concentration of 100 microM (mipafox concentration: 0-1000 microM) resulted in a mipafox I50 of 7.3 microM for chicken brain NTE and 11.6 microM for rat brain NTE. NTE (i.e., paraoxon-resistant, mipafox-sensitive esterase activity) comprised 80% of chicken and 60% of rat brain paraoxon-resistant activity with the specific activity of chicken brain NTE approximately twice that of rat brain NTE. The pH maxima for NTE from both species was similar showing broad, slightly alkaline optima from pH 7.9 to 8.6. [ 3 H]Diisopropyl phosphorofluoridate (DFP)-labeled NTE from the brains of both species had an apparent mol wt of 160,000 measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In conclusion, NTE from both species was very similar, with the mipafox I50 for rat NTE within the range of reported values for chicken and human NTE, and the inhibitor parameters of the chicken NTE assay were applicable for the rat NTE assay

  12. Erythrocyte membrane stabilization effect and antioxidant activity of methyl methacrylate

    International Nuclear Information System (INIS)

    Popov, B.

    2004-01-01

    Methyl methacrylate (MMK) is a synthetic product with mild impact on human health that is not well studied on cellular basis. Here, human erythrocytes were used to investigate the effects MMK exerts on acid and heat-induced hemolysis. Biphasic effect of MMK was observed for acid-induced hemolysis; i.e., protection at low (0 - 0.05% v/v) and stimulation at higher (0.1- 0.4% v/v) concentrations. The maximal protective effect was produced at 0.03% (v/v). At this concentration MMK increased the temperatures of heat denaturation of erythrocyte membrane proteins, spectrin and integral proteins, by about 2 0 C and inhibited the heat-induced hemolysis by 20 %. This membrane stabilization effect of MMK is similar to that produced by some anti-inflammatory and antirheumatic drugs. The increased acid resistance possibly indicated anti-oxidant properties of MMK. The nonenzymatic antioxidant activity test evidenced that MMK has no superoxide dismutase-like activity but demonstrates strong catalase-like activity (about 900 kU/mmol at 0.05-0.1 mmol/l concentration). The results indicate that at low concentration MMK exerts benign effect on cellular membrane that could find therapeutic usage. (author)

  13. Hepatic esterase activity is increased in hepatocyte-like cells derived from human embryonic stem cells using a 3D culture system.

    Science.gov (United States)

    Choi, Young-Jun; Kim, Hyemin; Kim, Ji-Woo; Yoon, Seokjoo; Park, Han-Jin

    2018-05-01

    The aim of the study is to generate a spherical three-dimensional (3D) aggregate of hepatocyte-like cells (HLCs) differentiated from human embryonic stem cells and to investigate the effect of the 3D environment on hepatic maturation and drug metabolism. Quantitative real-time PCR analysis indicated that gene expression of mature hepatocyte markers, drug-metabolizing enzymes, and hepatic transporters was significantly higher in HLCs cultured in the 3D system than in those cultured in a two-dimensional system (p formation, were increased in HLCs cultured in the 3D system. In particular, 3D spheroidal culture increased expression of CES1 and BCHE, which encode hepatic esterases (p 3D spheroidal culture enhances the maturation and drug metabolism of stem cell-derived HLCs, and this may help to optimize hepatic differentiation protocols for hepatotoxicity testing.

  14. Functional classification of esterases from leaves of Aspidosperma polyneuron M. Arg. (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Carvalho Vanda Marilza de

    2003-01-01

    Full Text Available Polyacrylamide gel electrophoresis system (PAGE and inhibition tests for biochemical characterization of alpha- and beta-esterases were used to obtain a functional classification of esterases fromAspidosperma polyneuron. The characterization of alpha- and beta-esterases from young leaves of A. polyneuron by the PAGE system showed fourteen esterase isozymes. The differential staining pattern showed that Est-2 isozyme hydrolyzes beta-naphthyl acetate; Est-6, Est-7 and Est-8 isozymes hydrolyze alpha-naphthyl acetate, and Est-1, Est-3, Est-4, Est-5, Est-9, Est-10, Est-11, Est-12, Est-13, and Est-14 isozymes hydrolyze both alpha- and b-naphthyl acetate. Inhibition pattern of a- and beta-esterases showed that Folidol is a more potent inhibitor that Malathion, while Thiamethoxan (an insecticide with organophosphorus-like action acts as an Est-4 and Est-6 inhibitor and induces the appearance of Est-5 and Est-7 isozymes as more intensely stained bands. Inhibition tests showed that OPC insecticides inhibit or activate plant esterases. Thus, plant esterases may be used as bioindicators to detect the presence and toxicity of residues of topically applied insecticides in agriculture and may be valuable for monitoring pollutants in the environment.

  15. Reductive methylation of insulin. Production of a biologically active tritiated insulin

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, J W; Nahum, A; Steiner, D F [Department of Biochemistry, University of Chicago, Illinois, USA

    1983-01-01

    Reductive methylation of the three amino groups of porcine insulin was accomplished by incubation with formaldehyde and sodium cyanoborohydride. The two amino termini and the epsilon amino group of B29 lysine were each dimethylated within 1 h of incubation. The fully methylated insulin bound more tightly to a reverse phase column than did native insulin, had a slightly more acid isoelectric point, and maintained approximately 50% biological activity when examined with an insulin sensitive cultured cell line. Reductive methylation with sodium cyanoboro (/sup 3/H) hydride resulted in a (/sup 3/H) methylated insulin with a specific activity of 6 Ci/mmol.

  16. Hemi-methylated DNA regulates DNA methylation inheritance through allosteric activation of H3 ubiquitylation by UHRF1.

    Science.gov (United States)

    Harrison, Joseph S; Cornett, Evan M; Goldfarb, Dennis; DaRosa, Paul A; Li, Zimeng M; Yan, Feng; Dickson, Bradley M; Guo, Angela H; Cantu, Daniel V; Kaustov, Lilia; Brown, Peter J; Arrowsmith, Cheryl H; Erie, Dorothy A; Major, Michael B; Klevit, Rachel E; Krajewski, Krzysztof; Kuhlman, Brian; Strahl, Brian D; Rothbart, Scott B

    2016-09-06

    The epigenetic inheritance of DNA methylation requires UHRF1, a histone- and DNA-binding RING E3 ubiquitin ligase that recruits DNMT1 to sites of newly replicated DNA through ubiquitylation of histone H3. UHRF1 binds DNA with selectivity towards hemi-methylated CpGs (HeDNA); however, the contribution of HeDNA sensing to UHRF1 function remains elusive. Here, we reveal that the interaction of UHRF1 with HeDNA is required for DNA methylation but is dispensable for chromatin interaction, which is governed by reciprocal positive cooperativity between the UHRF1 histone- and DNA-binding domains. HeDNA recognition activates UHRF1 ubiquitylation towards multiple lysines on the H3 tail adjacent to the UHRF1 histone-binding site. Collectively, our studies are the first demonstrations of a DNA-protein interaction and an epigenetic modification directly regulating E3 ubiquitin ligase activity. They also define an orchestrated epigenetic control mechanism involving modifications both to histones and DNA that facilitate UHRF1 chromatin targeting, H3 ubiquitylation, and DNA methylation inheritance.

  17. MIRA: An R package for DNA methylation-based inference of regulatory activity.

    Science.gov (United States)

    Lawson, John T; Tomazou, Eleni M; Bock, Christoph; Sheffield, Nathan C

    2018-03-01

    DNA methylation contains information about the regulatory state of the cell. MIRA aggregates genome-scale DNA methylation data into a DNA methylation profile for independent region sets with shared biological annotation. Using this profile, MIRA infers and scores the collective regulatory activity for each region set. MIRA facilitates regulatory analysis in situations where classical regulatory assays would be difficult and allows public sources of open chromatin and protein binding regions to be leveraged for novel insight into the regulatory state of DNA methylation datasets. R package available on Bioconductor: http://bioconductor.org/packages/release/bioc/html/MIRA.html. nsheffield@virginia.edu.

  18. Esterase inhibition by synergists in the western flower thrips Frankliniella occidentalis.

    Science.gov (United States)

    López-Soler, Neus; Cervera, Amelia; Quinto, Vicente; Abellán, Jaime; Bielza, Pablo; Martínez-Pardo, Rafael; Garcerá, Maria Dolores

    2011-12-01

    Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is among the most important crop pests in the south-eastern region of Spain. Its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. Use of synergists to inhibit the enzymes involved in insecticide detoxification is widely used to determine their responsibility for insecticide resistance. However, they do not always act as intended or expected, and caution must be exercised when interpreting synergist results. Laboratory-selected strains of WFT were used to analyse the effects of the synergists piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and methiocarb on total esterase activity. Significant differences were found, indicating esterase activity inhibition by DEF, a lower effect for methiocarb and a small inhibition of the activity by PBO. Esterase isoenzyme inhibition by these compounds showed a similar result; this assay revealed an extreme sensitivity of Triplet A (resistance-associated esterases) to DEF. In an in vivo assay carried out with these compounds at different incubation times, only DEF caused posterior in vitro esterase activity inhibition, with a maximum effect 1 h after treatment. In this work, only DEF shows true synergistic inhibition of WFT esterases. Copyright © 2011 Society of Chemical Industry.

  19. Heterologous production and characterization of a chlorogenic acid esterase from Ustilago maydis with a potential use in baking.

    Science.gov (United States)

    Nieter, Annabel; Kelle, Sebastian; Takenberg, Meike; Linke, Diana; Bunzel, Mirko; Popper, Lutz; Berger, Ralf G

    2016-10-15

    Ustilago maydis, an edible mushroom growing on maize (Zea mays), is consumed as the food delicacy huitlacoche in Mexico. A chlorogenic acid esterase from this basidiomycete was expressed in good yields cultivating the heterologous host Pichia pastoris on the 5L bioreactor scale (reUmChlE; 45.9UL(-1)). In contrast to previously described chlorogenic acid esterases, the reUmChlE was also active towards feruloylated saccharides. The enzyme preferred substrates with the ferulic acid esterified to the O-5 position of arabinose residues, typical of graminaceous monocots, over the O-2 position of arabinose or the O-6 position of galactose residues. Determination of kcat/Km showed that the reUmChlE hydrolyzed chlorogenic acid 18-fold more efficiently than methyl ferulate, p-coumarate or caffeate. Phenolic acids were released by reUmChlE from natural substrates, such as destarched wheat bran, sugar beet pectin and coffee pulp. Treatment of wheat dough using reUmChlE resulted in a noticeable softening indicating a potential application of the enzyme in bakery and confectionery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Identifying carcinogenic activity of methylated and non-methylated polycyclic aromatic hydrocarbons (PAHs) through electronic and topological indices

    CERN Document Server

    Braga, R S; Barone, P M V B

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are a class of planar molecules, abundant in urban environment, which can induce chemical carcinogenesis. Their carcinogenic power varies in a large range, from very strong carcinogens to inactive ones. In a previous study, we proposed a methodology to identify the PAHs carcinogenic activity exploring electronic and topological indices. In the present work, we show that it is possible to simplify that methodology and expand its applicability to include methylated PAHs compounds. Using very simple rules, we can predict their carcinogenic activity with high accuracy (approx 89%).

  1. Altered mucosal DNA methylation in parallel with highly active Helicobacter pylori-related gastritis.

    Science.gov (United States)

    Yoshida, Takeichi; Kato, Jun; Maekita, Takao; Yamashita, Satoshi; Enomoto, Shotaro; Ando, Takayuki; Niwa, Tohru; Deguchi, Hisanobu; Ueda, Kazuki; Inoue, Izumi; Iguchi, Mikitaka; Tamai, Hideyuki; Ushijima, Toshikazu; Ichinose, Masao

    2013-10-01

    Chronic inflammation triggered by Helicobacter pylori causes altered DNA methylation in stomach mucosae, which is deeply involved in gastric carcinogenesis. This study aimed to elucidate the correlation between altered mucosal DNA methylation levels and activity of H. pylori-related gastritis, because inflammatory activity shows particular correlations with the development of diffuse-type cancer. Methylation levels in stomach mucosae of 78 healthy volunteers were determined by real-time methylation-specific PCR or bisulfite pyrosequencing. Examined loci were the promoter CpG islands of six genes (FLNc, HAND1, THBD, p41ARC, HRASLS, and LOX) and the CpG sites of non-coding repetitive elements (Alu and Satα) that are reportedly altered by H. pylori infection. Activity of H. pylori-related gastritis was evaluated using two serum markers: H. pylori antibody titer and pepsinogen II. Methylation levels of the six CpG islands were consistently increased, and those of the two repetitive elements were consistently decreased in a stepwise manner with the activity of gastric inflammation as represented by serum marker levels. Each serum marker level was well correlated with the overall DNA methylation status of stomach mucosa, and these two serologic markers were additive in the detection of the mucosa with severely altered DNA methylation. Alteration in mucosal DNA methylation level was closely correlated with activity of H. pylori-related gastritis as evaluated by serum markers. The observed correlation between altered DNA methylation levels and activity of H. pylori-related gastritis appears to be one of the relevant molecular mechanisms underlying the development of diffuse-type cancer.

  2. 3 Benzyl-6-chloropyrone: a suicide inhibitor of cholesterol esterase

    International Nuclear Information System (INIS)

    Saint, C.; Gallo, I.; Kantorow, M.; Bailey, J.M.

    1986-01-01

    Cholesterol, absorbed from the intestine, appears in lymph as the ester. Cholesterol esterase is essential for this process, since depletion of the enzyme blocks and repletion restores, absorption. Selective inhibitors of cholesterol esterase may thus prove useful in reducing cholesterol uptake. A series of potential suicide substrates were synthesized which, following cleavage by the enzyme, would attack the putative nucleophile in the active site. One of these, 3-benzyl-6-chloropyrone (3BCP), inhibited both synthesis and hydrolysis of 14 C-cholesteryl oleate with an I 50 of approximately 150 μM. The inactivation was time-dependent and characteristic of a suicide mechanism. The α pyrone structure (lactone analog) is cleaved by a serine-hydroxyl in the active site. This generates an enoyl chloride which inactivates the imidazole believed to play a part in the catalytic function of the enzyme. Inhibition by 3BCP is selective for cholesterol esterase. The activity of pancreatic lipase as not affected by concentrations up to 1 mM

  3. Synthesis and antinociceptive activity of methyl nicotinate | Erharuyi ...

    African Journals Online (AJOL)

    ... neutralization of the reaction mixture with 10% sodium bicarbonate. The product was purified by column chromatography and purity ascertained by thin layer chromatography. Structure of the desired product was confirmed by NMR and Mass spectroscopy. Methyl nicotinate was obtained as a white powder (m.p. 40-42oC, ...

  4. Esterase resistant to inactivation by heavy metals

    KAUST Repository

    El, Dorry Hamza

    2014-09-25

    EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II brine pool is an extreme environment that possesses multiple harsh conditions such as; high temperature, salinity, pH and high concentration of metals, including toxic heavy metals. A fosmid metagenomic library using DNA isolated from the lowest convective layer this pool was used to identify EstATII. Polynucleotides encoding EstATII and similar esterases are disclosed and can be used to make EstATII. EstATII or compositions or apparatuses that contain it may be used in various processes employing lipases/esterases especially when these processes are performed under harsh conditions that inactivate other kinds of lipases or esterases.

  5. Removal efficiency of radioactive methyl iodide on TEDA-impregnated activated carbons

    International Nuclear Information System (INIS)

    Gonzalez-Garcia, C.M.; Gonzalez, J.F.; Roman, S.

    2011-01-01

    Activated carbons were prepared by different series of carbon dioxide and steam activation from walnut shells for their optimal use as radioactive methyl iodide adsorbents in Nuclear Plants. The knowledge of the most favourable textural characteristics of the activated carbons was possible by the previous study of the commercial activated carbon currently used for this purpose. In order to increase their methyl iodide affinity, the effect of triethylenediamine impregnation was studied at 5 and 10 wt.%. The results obtained indicated that in both cases the adsorption efficiency is markedly improved by the addition of impregnant, which allows the adsorbate uptake to occur not only by physical adsorption, via non-specific interactions (as in non-impregnated carbons) but also by the specific interaction of triethylenediamine with radioactive methyl iodide. Methyl iodide retention efficiencies up to 98.1% were achieved. (author)

  6. Functional Cloning and Expression of the Schizophyllum commune Glucuronoyl Esterase Gene and Characterization of the Recombinant Enzyme

    Science.gov (United States)

    Wong, Dominic W. S.; Chan, Victor J.; McCormack, Amanda A.; Hirsch, Ján; Biely, Peter

    2012-01-01

    The gene encoding Schizophyllum commune glucuronoyl esterase was identified in the scaffold 17 of the genome, containing two introns of 50 bp and 48 bp, with a transcript sequence of 1179 bp. The gene was synthesized and cloned into Pichia pastoris expression vector pGAPZα to achieve constitutive expression and secretion of the recombinant enzyme in soluble active form. The purified protein was 53 kD with glycosylation and had an acidic pI of 3.7. Activity analysis on several uronic acids and their derivatives suggests that the enzyme recognized only esters of 4-O-methyl-D-glucuronic acid derivatives, even with a 4-nitrophenyl aglycon but did not hydrolyze the ester of D-galacturonic acid. The kinetic values were K m 0.25 mM, V max 16.3 μM·min−1, and k cat 9.27 s−1 with 4-nitrophenyl 2-O-(methyl 4-O-methyl-α-D-glucopyranosyluronate)-β-D-xylopyranoside as the substrate. PMID:22844600

  7. Properties of Two Novel Esterases Identified from Culture Supernatant of Penicillium purpurogenum Grown on Sugar Beet Pulp.

    Science.gov (United States)

    Oleas, Gabriela; Callegari, Eduardo; Sepulveda, Romina; Eyzaguirre, Jaime

    2016-01-01

    The filamentous fungus Penicillium purpurogenum grows on a variety of natural carbon sources, such as sugar beet pulp, and secretes to the medium a large number of enzymes that degrade the carbohydrate components of lignocellulose. Sugar beet pulp is rich in pectin, and the purpose of this work is to identify novel esterases produced by the fungus, which may participate in pectin degradation. Partially purified culture supernatants of the fungus grown on sugar beet pulp were subjected to mass spectrometry analysis. Peptides thus identified, which may be part of potential esterases were probed against the proteins deduced from the fungal genome sequence. The cDNAs of two putative esterases identified were expressed in Pichia pastoris and their properties studied. One of these enzymes, named FAET, is a feruloyl esterase, while the other, PE, is classified as a pectin methyl esterase. These findings add to our knowledge of the enzymology of pectin degradation by Penicillium purpurogenum, and define properties of two novel esterases acting on de-esterification of pectin. Their availability may be useful as tools for the study of pectin structure and degradation.

  8. Activity of cell wall degrading glycanases in methyl jasmonate-induced leaf abscission in Kalanchoe blossfeldiana

    OpenAIRE

    Marian Saniewski; Ewa Gajewska; Henryk Urbanek

    2013-01-01

    It was found previously that methyl jasmonate (JA-Me) induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in thi...

  9. BDNF Methylation and Maternal Brain Activity in a Violence-Related Sample.

    Directory of Open Access Journals (Sweden)

    Dominik A Moser

    Full Text Available It is known that increased circulating glucocorticoids in the wake of excessive, chronic, repetitive stress increases anxiety and impairs Brain-Derived Neurotrophic Factor (BDNF signaling. Recent studies of BDNF gene methylation in relation to maternal care have linked high BDNF methylation levels in the blood of adults to lower quality of received maternal care measured via self-report. Yet the specific mechanisms by which these phenomena occur remain to be established. The present study examines the link between methylation of the BDNF gene promoter region and patterns of neural activity that are associated with maternal response to stressful versus non-stressful child stimuli within a sample that includes mothers with interpersonal violence-related PTSD (IPV-PTSD. 46 mothers underwent fMRI. The contrast of neural activity when watching children-including their own-was then correlated to BDNF methylation. Consistent with the existing literature, the present study found that maternal BDNF methylation was associated with higher levels of maternal anxiety and greater childhood exposure to domestic violence. fMRI results showed a positive correlation of BDNF methylation with maternal brain activity in the anterior cingulate (ACC, and ventromedial prefrontal cortex (vmPFC, regions generally credited with a regulatory function toward brain areas that are generating emotions. Furthermore we found a negative correlation of BDNF methylation with the activity of the right hippocampus. Since our stimuli focus on stressful parenting conditions, these data suggest that the correlation between vmPFC/ACC activity and BDNF methylation may be linked to mothers who are at a disadvantage with respect to emotion regulation when facing stressful parenting situations. Overall, this study provides evidence that epigenetic signatures of stress-related genes can be linked to functional brain regions regulating parenting stress, thus advancing our understanding of

  10. Esterase variation in Turkish white-toothed shrews (Crocidura: Record of a trimeric esterase

    Directory of Open Access Journals (Sweden)

    Tez C.

    2009-01-01

    Full Text Available This study focuses on esterase variation of the genus Crocidura in Turkey. A total of 248 white-toothed shrews were analyzed by means of cellulose acetate gel electrophoresis. Liver tissue and alfa naphthyl acetate were used to investigate esterase variation in Turkish white-toothed shrews. A different esterase banding pattern was found in one Crocidura individual. This phenotype had four anodally migrated bands on cellulose acetate gel. The Crocidura individual displaying the given phenotype was identified as Crocidura suaveolens. The different esterase banding pattern observed in this study is considered to be a result of the trimeric structure of esterase in the lesser white-toothed shrew (Crocidura suaveolens.

  11. Enhanced biosurfactant production through cloning of three genes and role of esterase in biosurfactant release

    Science.gov (United States)

    2011-01-01

    Background Biosurfactants have been reported to utilize a number of immiscible substrates and thereby facilitate the biodegradation of panoply of polyaromatic hydrocarbons. Olive oil is one such carbon source which has been explored by many researchers. However, studying the concomitant production of biosurfactant and esterase enzyme in the presence of olive oil in the Bacillus species and its recombinants is a relatively novel approach. Results Bacillus species isolated from endosulfan sprayed cashew plantation soil was cultivated on a number of hydrophobic substrates. Olive oil was found to be the best inducer of biosurfactant activity. The protein associated with the release of the biosurfactant was found to be an esterase. There was a twofold increase in the biosurfactant and esterase activities after the successful cloning of the biosurfactant genes from Bacillus subtilis SK320 into E.coli. Multiple sequence alignment showed regions of similarity and conserved sequences between biosurfactant and esterase genes, further confirming the symbiotic correlation between the two. Biosurfactants produced by Bacillus subtilis SK320 and recombinant strains BioS a, BioS b, BioS c were found to be effective emulsifiers, reducing the surface tension of water from 72 dynes/cm to as low as 30.7 dynes/cm. Conclusion The attributes of enhanced biosurfactant and esterase production by hyper-producing recombinant strains have many utilities from industrial viewpoint. This study for the first time has shown a possible association between biosurfactant production and esterase activity in any Bacillus species. Biosurfactant-esterase complex has been found to have powerful emulsification properties, which shows promising bioremediation, hydrocarbon biodegradation and pharmaceutical applications. PMID:21707984

  12. Biological activity of 2,3-Di (quinolyl-2)-6-methyl quinoxaline

    International Nuclear Information System (INIS)

    Ansar, N.; Kaban, S.; Ahmed, R.

    2003-01-01

    The biological activities of the nitrogen containing conjugated heterocyclic compounds are considerably used pharmaceutically as antiulcer, antimalarial, tubercluocidal and sedatives besides their uses as dyes in the textile industries, pesticides, stabilizers and inhibitors etc. 2.3-Di(quinolyl-2)-6-methyl quinoxaline was synthesized by condensation followed by ring closure reaction when 1,2-di(quinolyl-2)-1,2 ethanedione was treated with methyl and substituted o-phenylenediamine. (author)

  13. Biological activity of 2,3-Di (quinolyl-2)-6-methyl quinoxaline

    Energy Technology Data Exchange (ETDEWEB)

    Ansar, N [Adamjee Government Science College, Karachi (Pakistan). Dept. of Chemistry; Kaban, S [Yildiz Technical Univ., Istanbul (Turkey). Dept. of Chemistry; Ahmed, R [University of Karachi, Karachi (Pakistan). Dept. of Chemistry

    2003-06-01

    The biological activities of the nitrogen containing conjugated heterocyclic compounds are considerably used pharmaceutically as antiulcer, antimalarial, tubercluocidal and sedatives besides their uses as dyes in the textile industries, pesticides, stabilizers and inhibitors etc. 2.3-Di(quinolyl-2)-6-methyl quinoxaline was synthesized by condensation followed by ring closure reaction when 1,2-di(quinolyl-2)-1,2 ethanedione was treated with methyl and substituted o-phenylenediamine. (author)

  14. Purification and properties of a novel quizalofop-p-ethyl-hydrolyzing esterase involved in quizalofop-p-ethyl degradation by Pseudomonas sp. J-2.

    Science.gov (United States)

    Zhang, Hui; Li, Mengya; Li, Jie; Wang, Guangli; Liu, Yuan

    2017-05-10

    Quizalofop-p-ethyl (QPE) is a post-emergence herbicide that effectively controls grass weeds and is often detected in the environment. However, the biochemical and molecular mechanisms of QPE degradation in the environment remains unclear. In this study, a highly effective QPE-degrading bacterial strain J-2 was isolated from acclimated activated sludge and identified as a Pseudomonas sp., containing the QPE breakdown metabolite quizalofop acid (QA) identified by Liquid Chromatography-Ion Trap-Mass Spectrometry (LC-IT-MS n ) analysis. A novel QPE hydrolase esterase-encoding gene qpeH was cloned from strain J-2 and functionally expressed in Escherichia coli BL21 (DE3). The specific activity of recombinant QpeH was 198.9 ± 2.7 U mg -1 for QPE with K m and K cat values of 41.3 ± 3.6 μM and 127.3 ± 4.5 s -1 . The optimal pH and temperature for the recombinant QpeH were 8.0 and 30 °C, respectively and the enzyme was activated by Ca 2+ , Cd 2+ , Li + , Fe 3+ and Co 2+ and inhibited by Ni 2+ , Fe 2+ , Ag + , DEPC, SDS, Tween 80, Triton X, β-mercaptoethanol, PMSF, and pCMB. In addition, the catalytic efficiency of QpeH toward different AOPP herbicides in descending order was as follows: fenoxaprop-P-ethyl > quizalofop-P-tefuryl > QPE > haloxyfop-P-methyl > cyhalofopbutyl > clodinafop-propargyl. On the basis of the phylogenetic analysis and multiple sequence alignment, the identified enzyme QpeH, was clustered with esterase family V, suggesting a new member of this family because of its low similarity of amino acid sequence with esterases reported previously.

  15. Diversity of hydrolases from hydrothermal vent sediments of the Levante Bay, Vulcano Island (Aeolian archipelago) identified by activity-based metagenomics and biochemical characterization of new esterases and an arabinopyranosidase.

    Science.gov (United States)

    Placido, Antonio; Hai, Tran; Ferrer, Manuel; Chernikova, Tatyana N; Distaso, Marco; Armstrong, Dale; Yakunin, Alexander F; Toshchakov, Stepan V; Yakimov, Michail M; Kublanov, Ilya V; Golyshina, Olga V; Pesole, Graziano; Ceci, Luigi R; Golyshin, Peter N

    2015-12-01

    A metagenomic fosmid expression library established from environmental DNA (eDNA) from the shallow hot vent sediment sample collected from the Levante Bay, Vulcano Island (Aeolian archipelago) was established in Escherichia coli. Using activity-based screening assays, we have assessed 9600 fosmid clones corresponding to approximately 350 Mbp of the cloned eDNA, for the lipases/esterases/lactamases, haloalkane and haloacid dehalogenases, and glycoside hydrolases. Thirty-four positive fosmid clones were selected from the total of 120 positive hits and sequenced to yield ca. 1360 kbp of high-quality assemblies. Fosmid inserts were attributed to the members of ten bacterial phyla, including Proteobacteria, Bacteroidetes, Acidobateria, Firmicutes, Verrucomicrobia, Chloroflexi, Spirochaetes, Thermotogae, Armatimonadetes, and Planctomycetes. Of ca. 200 proteins with high biotechnological potential identified therein, we have characterized in detail three distinct α/β-hydrolases (LIPESV12_9, LIPESV12_24, LIPESV12_26) and one new α-arabinopyranosidase (GLV12_5). All LIPESV12 enzymes revealed distinct substrate specificities tested against 43 structurally diverse esters and 4 p-nitrophenol carboxyl esters. Of 16 different glycosides tested, the GLV12_5 hydrolysed only p-nitrophenol-α-(L)-arabinopyranose with a high specific activity of about 2.7 kU/mg protein. Most of the α/β-hydrolases were thermophilic and revealed a high tolerance to, and high activities in the presence of, numerous heavy metal ions. Among them, the LIPESV12_24 was the best temperature-adapted, retaining its activity after 40 min of incubation at 90 °C. Furthermore, enzymes were active in organic solvents (e.g., >30% methanol). Both LIPESV12_24 and LIPESV12_26 had the GXSXG pentapeptides and the catalytic triads Ser-Asp-His typical to the representatives of carboxylesterases of EC 3.1.1.1.

  16. Isolation and characterization of novel lipases/esterases from a bovine rumen metagenome.

    Science.gov (United States)

    Privé, Florence; Newbold, C Jamie; Kaderbhai, Naheed N; Girdwood, Susan G; Golyshina, Olga V; Golyshin, Peter N; Scollan, Nigel D; Huws, Sharon A

    2015-07-01

    Improving the health beneficial fatty acid content of meat and milk is a major challenge requiring an increased understanding of rumen lipid metabolism. In this study, we isolated and characterized rumen bacterial lipases/esterases using functional metagenomics. Metagenomic libraries were constructed from DNA extracted from strained rumen fluid (SRF), solid-attached bacteria (SAB) and liquid-associated rumen bacteria (LAB), ligated into a fosmid vector and subsequently transformed into an Escherichia coli host. Fosmid libraries consisted of 7,744; 8,448; and 7,680 clones with an average insert size of 30 to 35 kbp for SRF, SAB and LAB, respectively. Transformants were screened on spirit blue agar plates containing tributyrin for lipase/esterase activity. Five SAB and four LAB clones exhibited lipolytic activity, and no positive clones were found in the SRF library. Fosmids from positive clones were pyrosequenced and twelve putative lipase/esterase genes and two phospholipase genes retrieved. Although the derived proteins clustered into diverse esterase and lipase families, a degree of novelty was seen, with homology ranging from 40 to 78% following BlastP searches. Isolated lipases/esterases exhibited activity against mostly short- to medium-chain substrates across a range of temperatures and pH. The function of these novel enzymes recovered in ruminal metabolism needs further investigation, alongside their potential industrial uses.

  17. Solid-state fermentation as a potential technique for esterase/lipase production by halophilic archaea.

    Science.gov (United States)

    Martin del Campo, Martha; Camacho, Rosa M; Mateos-Díaz, Juan C; Müller-Santos, Marcelo; Córdova, Jesus; Rodríguez, Jorge A

    2015-11-01

    Halophilic archaea are extremophiles, adapted to high-salt environments, showing a big biotechnological potential as enzyme, lipids and pigments producers. Four inert supports (perlite, vermiculite, polyurethane foam and glass fiber) were employed for solid-state fermentation (SSF) of the halophilic archaeon Natronococcus sp. TC6 to investigate biomass and esterase production. A very low esterase activity and high water activity were observed when perlite, vermiculite and polyurethane were used as supports. When glass fiber was employed, an important moisture loss was observed (8.6%). Moreover, moisture retention was improved by mixing polyurethane and glass fiber, resulting in maximal biomass and esterase production. Three halophilic archaea: Natronococcus sp. TC6, Halobacterium sp. NRC-1 and Haloarcula marismortui were cultured by submerged fermentation (SmF) and by SSF; an improvement of 1.3- to 6.2-fold was observed in the biomass and esterase production when SSF was used. Growth was not homogeneous in the mixture, but was predominant in the glass fiber thus was probably because the glass fiber provides a holder to the cells, while the polyurethane acts as an impregnation medium reservoir. To the best of our knowledge, this work is the first report on haloarchaea cultivation by SSF aiming biomass and esterase/lipase activity production.

  18. Biodegradation of triclosan and formation of methyl-triclosan in activated sludge under aerobic conditions

    DEFF Research Database (Denmark)

    Chen, Xijuan; Nielsen, Jeppe Lund; Furgal, Karolina

    2011-01-01

    of triclosan- methyl was investigated in activated sludge from a standard activated sludge WWTP equipped with enhanced biological phosphorus removal. The removal was found to occur mainly under aerobic conditions while under anoxic (nitrate reducing) and anaerobic conditions rather low removal rates were...... determined. In a laboratory-scale activated sludge reactor 75% of the triclosan was removed under aerobic conditions within 150 h, while no removal was observed under anaerobic or anoxic conditions. One percent of the triclosan was converted to triclosan-methyl under aerobic conditions, less under anoxic...

  19. Effect of pesticide applications on soil microbial activity and on 14C-methyl parathion dissipation

    International Nuclear Information System (INIS)

    Peres, Terezinha Bonanho

    2000-01-01

    Some crops, as cotton, need different pesticide application to control pests and diseases. These compounds reach soil and may affect the soil microbial activity. As the microorganisms play important role on the nutrient cycling, changes in their activities may affect the soil fertility. The influence of several pesticides on soil microbial activity of the 0-15 cm and 15-30 cm depth of the soil profile, and the 14 C-methyl parathion dissipation was studied under influence of other pesticide applications. The influence of pesticides on the microorganisms was followed in an experimental area of the Instituto Biologico, that was divided in two subareas, both under cotton crop. Columns of PVC was buried in both subareas and a solution of 14 C-methyl parathion diluted in the technical compound was applied on the soil surface of each column. One subarea received all the recommended pesticides for the cotton crop besides the 14 C-methyl parathion. The other subarea received only 14 C-methyl parathion solution on the columns soil surface. The soil microbial activity of both subareas was estimated by measurements of dehydrogenase, arylsulfatase and arginine deaminase enzymes. Further, the availability of total nitrogen in the soil was also measured. The dissipation of 14 C-methyl parathion was studied by radiocarbon recovery in soil extracts and combustion of extracted soil and quantification by radiometric techniques. (author)

  20. The Effects of Fenarimol and Methyl Parathion on Glucose 6-Phosphate Dehydrogenase Enzyme Activity in Rats

    Directory of Open Access Journals (Sweden)

    Ferda ARI

    2017-10-01

    Full Text Available Fenarimol and methyl parathion are pesticides that have been used in agriculture for several years. These pesticides have significant effects on environmental and human health. Therefore, we investigated the effects of methyl parathion and fenarimol on glucose 6-phosphate dehydrogenase (EC 1.1.1.49 enzyme activity in rats. The glucose 6- phosphate dehydrogenase is the first enzyme of the pentose phosphate pathway and it is important in detoxifying reactions by NADPH generated. In this study, wistar albino rats administrated with methyl parathion (7 mg kg–1 and fenarimol (200 mg kg−1 by intraperitoneally for different periods (2, 4, 8, 16, 32, 64, and 72 h. The glucose 6-phosphate dehydrogenase enzyme activity was assayed in liver, kidney, brain, and small intestine in male and female rats. The exposure of fenarimol and methyl parathion caused increase of glucose 6-phosphate dehydrogenase enzyme activity in rat tissues, especially at last periods. We suggest that this increment of enzyme activity may be the reason of toxic effects of fenarimol and methyl parathion.

  1. Effects of Model Salivary Esterases and MMP Inhibition on the Restoration's Marginal Integrity and Potential Degradative Contribution of Cariogenic Bacteria

    Science.gov (United States)

    Huang, Bo

    Enzyme-catalyzed degradation of the restoration-tooth interface compromises interfacial integrity, thereby contributing to secondary caries, which is a major cause of resin-based restoration failure. It is hypothesized that in addition to salivary esterases, the cariogenic bacterium Streptococcus mutans has specific esterases that degrade the resin-dentin interface, releasing biodegradation by- products (BBPs) such as bis-hydroxy-propoxy-phenyl-propane (BisHPPP). In turn, BisHPPP affects S. mutans by stimulating the expression of esterases. Another hypothesis is that the biostability of the resin-dentin interface is affected by simulated salivary esterases, dentinal matrix metalloproteinase (MMP) inhibition, and restorative materials. To test the first hypothesis, putative esterase genes in S. mutans UA159 were identified, purified, and characterized. SMU_118c was identified as the dominant esterase in S. mutans UA159 and showed a similar hydrolytic activity profile to salivary esterases. BisHPPP upregulated expression of the SMU_118c gene and related protein in a concentration-dependent manner. This positive feedback process could accelerate the degradation of the restoration-tooth interface and lead to premature restoration failure. To test the second hypothesis, an in vitro model was established to evaluate the effects of salivary esterases, MMP inhibition and restorative materials on interfacial integrity. It was confirmed that interfacial integrity was compromised with time and was further deteriorated by simulated salivary esterases, as indicated by the greater depth of bacterial ingress and more bacterial biomass of biofilm along the interface. However, this process could be modulated by using different restorative materials and MMPs inhibition. This project elucidated the mechanistic interaction between oral bacteria and restorative materials and established a new, in vitro, and physiologically relevant model to assess the effect of material chemistry

  2. A novel feruloyl esterase from rumen microbial metagenome: Gene cloning and enzyme characterization in the release of mono- and diferulic acids

    Science.gov (United States)

    A feruloyl esterase (FAE) gene was isolated from a rumen microbial metagenome, cloned into E. coli, and expressed in active form. The enzyme (RuFae4) was classified as a Type D feruloyl esterase based on its action on synthetic substrates and ability to release diferulates. The RuFae4 alone releas...

  3. Contribution of soil esterase to biodegradation of aliphatic polyester agricultural mulch film in cultivated soils.

    Science.gov (United States)

    Yamamoto-Tamura, Kimiko; Hiradate, Syuntaro; Watanabe, Takashi; Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Yarimizu, Tohru; Kitamoto, Hiroko

    2015-01-01

    The relationship between degradation speed of soil-buried biodegradable polyester film in a farmland and the characteristics of the predominant polyester-degrading soil microorganisms and enzymes were investigated to determine the BP-degrading ability of cultivated soils through characterization of the basal microbial activities and their transition in soils during BP film degradation. Degradation of poly(butylene succinate-co-adipate) (PBSA) film was evaluated in soil samples from different cultivated fields in Japan for 4 weeks. Both the degradation speed of the PBSA film and the esterase activity were found to be correlated with the ratio of colonies that produced clear zone on fungal minimum medium-agarose plate with emulsified PBSA to the total number colonies counted. Time-dependent change in viable counts of the PBSA-degrading fungi and esterase activities were monitored in soils where buried films showed the most and the least degree of degradation. During the degradation of PBSA film, the viable counts of the PBSA-degrading fungi and the esterase activities in soils, which adhered to the PBSA film, increased with time. The soil, where the film was degraded the fastest, recorded large PBSA-degrading fungal population and showed high esterase activity compared with the other soil samples throughout the incubation period. Meanwhile, esterase activity and viable counts of PBSA-degrading fungi were found to be stable in soils without PBSA film. These results suggest that the higher the distribution ratio of native PBSA-degrading fungi in the soil, the faster the film degradation is. This could be due to the rapid accumulation of secreted esterases in these soils.

  4. Activity of cell wall degrading glycanases in methyl jasmonate-induced leaf abscission in Kalanchoe blossfeldiana

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2013-12-01

    Full Text Available It was found previously that methyl jasmonate (JA-Me induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in this way induces leaf abscission in Kalanchoe blossfeldiana.

  5. The effect of fixation on esterases

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1984-01-01

    The localization of reaction product for non-specific esterase from fresh and aldehyde treated glandular tissue was examined. The electrophoretical studies showed a selective inhibition of certain isoenzymes and a change in mobility of some bands caused by aldehyde fixation. In sections a granular...

  6. Esterase resistant to inactivation by heavy metals

    KAUST Repository

    El, Dorry Hamza; Siam, Rania; Mohamed, Yasmine M.

    2014-01-01

    EstATII is an esterase that a halotolerant, thermophilic and resistant to a spectrum of heavy metals including toxic concentration of metals. It was isolated from the lowest convective layer of the Atlantis II Red Sea brine pool. The Atlantis II

  7. Colorimetric determination of DNase I activity with a DNA-methyl green substrate.

    Science.gov (United States)

    Sinicropi, D; Baker, D L; Prince, W S; Shiffer, K; Shak, S

    1994-11-01

    A simple, high throughput, and precise assay was developed for quantification of deoxyribonuclease I (DNase; IUB 3.1.21.1) activity. The method was adapted from the procedure devised by Kurnick which employs a substrate comprised of highly polymerized native DNA complexed with methyl green. Hydrolysis of the DNA produced unbound methyl green and a decrease in the absorbance of the solution at 620 nm. By adjusting the time and temperature of the reaction, the assay permits quantification of DNase activity over a wide concentration range (0.4 to 8900 ng/ml). Samples and standards were added to the substrate in microtiter plates and were incubated for 1-24 h at 25-37 degrees C to achieve the desired assay range. The DNase activity of the samples was interpolated from a standard curve generated with Pulmozyme recombinant human deoxyribonuclease I (rhDNase). Interassay precision was less than 12% CV and recovery was within 100 +/- 11%. Activity determination by the DNA-methyl green method correlated well with that determined by the widely used "hyperchromicity" method originated by Kunitz, which is based on the increase in absorbance at 260 nm upon hydrolysis of DNA. The DNA-methyl green assay was simpler and more versatile than the hyperchromicity method and was used to characterize the activity of rhDNase and DNase isolated from human urine.

  8. A novel esterase from Saccharomyces carlsbergensis, a possible function for the yeast TIP1 gene

    DEFF Research Database (Denmark)

    Horsted, M W; Dey, E S; Holmberg, S

    1998-01-01

    An extracellular esterase was isolated from the brewer's yeast, Saccharomyces carlsbergensis. Inhibition by diisopropyl fluorophosphate shows that the enzyme has a serine active site. By mass spectrometry, the molecular weight of the enzyme was 16.9 kDa. The optimal pH for activity was in the range...

  9. C1-esterase inhibitor blocks T lymphocyte proliferation and cytotoxic T lymphocyte generation in vitro

    DEFF Research Database (Denmark)

    Nissen, Mogens Holst; Bregenholt, S; Nording, J A

    1998-01-01

    We have previously shown that activated C1s complement and activated T cells cleave beta2-microglobulin (beta2m) in vitro leading to the formation of desLys58 beta2m. This process can specifically be inhibited by C1-esterase inhibitor (C1-inh). Furthermore we showed that exogenously added desLys58...

  10. A New Functional Classification of Glucuronoyl Esterases by Peptide Pattern Recognition

    DEFF Research Database (Denmark)

    Wittrup Agger, Jane; Busk, Peter Kamp; Pilgaard, Bo

    2017-01-01

    of characterized enzymes exist and the exact activity is still uncertain. Here peptide pattern recognition is used as a bioinformatic tool to identify and group new CE15 proteins that are likely to have glucuronoyl esterase activity. 1024 CE15-like sequences were drawn from GenBank and grouped into 24 groups...

  11. The natural catalytic function of CuGE glucuronoyl esterase in hydrolysis of genuine lignin-carbohydrate complexes from birch

    DEFF Research Database (Denmark)

    Mosbech, Caroline; Holck, Jesper; Meyer, Anne S.

    2018-01-01

    Glucuronoyl esterases belong to carbohydrate esterase family 15 and catalyze de-esterification. Their natural function is presumed to be cleavage of ester linkages in lignin-carbohydrate complexes particularly those linking lignin and glucuronoyl residues in xylans in hardwood. Here, we show...... for the first time a detailed product profile of aldouronic acids released from birchwood lignin by a glucuronoyl esterase from the white-rot fungus Cerrena unicolor (CuGE). CuGE releases substrate for GH10 endo-xylanase which results in significantly increased product release compared to the action of endo......-xylanase alone. CuGE also releases neutral xylo-oligosaccharides that can be ascribed to the enzymes feruloyl esterase side activity as demonstrated by release of ferulic acid from insoluble wheat arabinoxylan. The data verify the enzyme's unique ability to catalyze removal of all glucuronoxylan associated...

  12. Methyl esterification of pectin plays a role during plant-pathogen interactions and affects plant resistance to diseases.

    Science.gov (United States)

    Lionetti, Vincenzo; Cervone, Felice; Bellincampi, Daniela

    2012-11-01

    The cell wall is a complex structure mainly composed by a cellulose-hemicellulose network embedded in a cohesive pectin matrix. Pectin is synthesized in a highly methyl esterified form and is de-esterified in muro by pectin methyl esterases (PMEs). The degree and pattern of methyl esterification affect the cell wall structure and properties with consequences on both the physiological processes of the plants and their resistance to pathogens. PME activity displays a crucial role in the outcome of the plant-pathogen interactions by making pectin more susceptible to the action of the enzymes produced by the pathogens. This review focuses on the impact of pectin methyl esterification in plant-pathogen interactions and on the dynamic role of its alteration during pathogenesis. Copyright © 2012 Elsevier GmbH. All rights reserved.

  13. Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Arumugham Suresh

    2014-09-01

    Full Text Available Objective: To evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. Methods: Antimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp., Candida sp., and Aspergillus niger and Aspergillus flavus. The FAME profiles were determined through gas chromatography with a flame ionization detector. Results: The FAME was found to be radial effective in inhibiting the radial growth of both bacterial and fungal pathogens. The FAME extracts exhibited the antibacterial activity against three clinical pathogens, namely, Escherichia coli, Salmonella typhi and Enterobacter sp. with the maximum zone of inhibition of 12.0 mm, 12.0 mm and 11.0 mm, respectively. The FAME showed moderate antifungal activity against Cryptococcus sp. (11.8 mm, Aspergillus niger (10.5 mm, Candida sp. (11.8 mm and Fusarium sp. (10.4 mm. Gas chromatography-flame ionization detector analysis revealed about 30 different FAMEs. Conclusions: We assume that the observed antimicrobial potency may be due to the abundance of erucic acid methyl ester (C22:0, arachidic acid methyl ester (C20:0, palmitic acid methyl ester (C16:0, cis-11-eicosenoicmethyl ester (C20:1, cis-11, 14-eicosadienoic acid methyl ester (C20:2 and linolenic acid methyl ester (C18:3 in FAMEs which appears to be promising to treat microbial diseases.

  14. Activities of natural methyl farnesoids on pupariation and metamorphosis of Drosophila melanogaster

    Science.gov (United States)

    Methyl farnesoate (MF) and juvenile hormone (JH III), which respectively bind to the receptors USP and MET, and bisepoxy JH III (bisJHIII) were assessed for several activities during Drosophila larval development, and during prepupal development to eclosed adults. Dietary MF and JH III were similar...

  15. Anti-Inflammatory Activity of Methyl Salicylate Glycosides Isolated from Gaultheria yunnanensis (Franch. Rehder

    Directory of Open Access Journals (Sweden)

    Guan-Hua Du

    2011-05-01

    Full Text Available Gaultheria yunnanensis (Franch. Rehder is a kind of traditional Chinese herbal medicine used for the treatments of rheumatoid arthritis, swelling and pain. Two methyl salicylate glycosides, namely methyl benzoate-2-O-b-D-xylopyranosyl(1-6-O-b-D-gluco-pyranoside (J12122 and methyl benzoate-2-O-β-D-xylopyranosyl(1-2[O-β-D-xylopyranosyl(1-6]-O-β-D-glucopyranoside (J12123, are natural salicylic derivatives isolated from Gaultheria yunnanensis. In this study, we investigated the anti-inflammatory activity of J12122 and J12123 on LPS-induced RAW264.7 macrophage cells by measuring the production of pro-inflammatory cytokines, accumulation of nitric oxide (NO, and level of reactive oxygen species (ROS. The results showed that both methyl salicylate glycosides dose-dependently inhibited the production of tumor necrosis factor-α (TNF-α, interleukin-1β (IL-1β, and IL-6, respectively. Consistent with these observations, J12122 and J12123 significantly suppressed the accumulation of NO, with an inhibitory rate of 56.20% and 51.72% at 3.0 μg/mL concentration, respectively. Furthermore, the two methyl salicylate glycosides reduced the level of ROS induced by LPS. These results showed that the isolated compounds possess anti-inflammatory properties through inhibition the production pro-inflammatory cytokines, NO, and ROS.

  16. Anti-inflammatory activity of methyl salicylate glycosides isolated from Gaultheria yunnanensis (Franch.) Rehder.

    Science.gov (United States)

    Zhang, Dan; Liu, Rui; Sun, Lan; Huang, Chao; Wang, Chao; Zhang, Dong-Ming; Zhang, Tian-Tai; Du, Guan-Hua

    2011-05-09

    Gaultheria yunnanensis (Franch.) Rehder is a kind of traditional Chinese herbal medicine used for the treatments of rheumatoid arthritis, swelling and pain. Two methyl salicylate glycosides, namely methyl benzoate-2-O-β-D-xylopyranosyl(1-6)-O-β-D-gluco-pyranoside (J12122) and methyl benzoate-2-O-β-D-xylopyranosyl(1-2)[O-β-D-xylopyranosyl(1-6)]-O-β-D-glucopyranoside (J12123), are natural salicylic derivatives isolated from Gaultheria yunnanensis. In this study, we investigated the anti-inflammatory activity of J12122 and J12123 on LPS-induced RAW264.7 macrophage cells by measuring the production of pro-inflammatory cytokines, accumulation of nitric oxide (NO), and level of reactive oxygen species (ROS). The results showed that both methyl salicylate glycosides dose-dependently inhibited the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6, respectively. Consistent with these observations, J12122 and J12123 significantly suppressed the accumulation of NO, with an inhibitory rate of 56.20% and 51.72% at 3.0 μg/mL concentration, respectively. Furthermore, the two methyl salicylate glycosides reduced the level of ROS induced by LPS. These results showed that the isolated compounds possess anti-inflammatory properties through inhibition the production pro-inflammatory cytokines, NO, and ROS.

  17. Parametric study on removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide

    International Nuclear Information System (INIS)

    Shiomi, H.; Yuasa, Y.; Tani, A.; Ohki, M.; Nakagawa, T.

    1983-01-01

    The removal efficiency of impregnated activated charcoal and silver zeolite for radioactive methyl iodide is influenced by various parameters such as temperature, relative humidity, face velocity and packing density. This study is to evaluate the dependency of the removal efficiency on each parameter and these combined parameters, quantitatively. Four types of adsorbents, BC-727, AgX, CHC-50 and SS 208C 5KI 3 , were tested. From experimental data and mass transfer theory, an experimental equation for evaluating the removal efficiency of adsorbents was derived under a series of experiments for radioactive methyl iodine-131. It was concluded that the removal efficiency calculated from the experimental equation agreed well with the experimental value. Effects of experimental specific parameters, such as Pre-flow time, methyl iodide injection time and After-flow time, on the removal efficiency of adsorbent are also described

  18. Branched nanotrees with immobilized acetylcholine esterase for nanobiosensor applications

    Energy Technology Data Exchange (ETDEWEB)

    Risveden, Klas; Bhand, Sunil; Danielsson, Bengt [Department of Pure and Applied Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, PO Box 124, SE-22100 Lund (Sweden); Dick, Kimberly A; Samuelson, Lars [Solid State Physics, Lund University, Box 118, S-22100 Lund (Sweden); Rydberg, Patrik, E-mail: Kimberly.Dick@ftf.lth.se [Department of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen (Denmark)

    2010-02-05

    A novel lab-on-a-chip nanotree enzyme reactor is demonstrated for the detection of acetylcholine. The reactors are intended for use in the RISFET (regional ion sensitive field effect transistor) nanosensor, and are constructed from gold-tipped branched nanorod structures grown on SiN{sub x}-covered wafers. Two different reactors are shown: one with simple, one-dimensional nanorods and one with branched nanorod structures (nanotrees). Significantly higher enzymatic activity is found for the nanotree reactors than for the nanorod reactors, most likely due to the increased gold surface area and thereby higher enzyme binding capacity. A theoretical calculation is included to show how the enzyme kinetics and hence the sensitivity can be influenced and increased by the control of electrical fields in relation to the active sites of enzymes in an electronic biosensor. The possible effects of electrical fields employed in the RISFET on the function of acetylcholine esterase is investigated using quantum chemical methods, which show that the small electric field strengths used are unlikely to affect enzyme kinetics. Acetylcholine esterase activity is determined using choline oxidase and peroxidase by measuring the amount of choline formed using the chemiluminescent luminol reaction.

  19. Correlating Gene-specific DNA Methylation Changes with Expression and Transcriptional Activity of Astrocytic KCNJ10 (Kir4.1).

    Science.gov (United States)

    Nwaobi, Sinifunanya E; Olsen, Michelle L

    2015-09-26

    DNA methylation serves to regulate gene expression through the covalent attachment of a methyl group onto the C5 position of a cytosine in a cytosine-guanine dinucleotide. While DNA methylation provides long-lasting and stable changes in gene expression, patterns and levels of DNA methylation are also subject to change based on a variety of signals and stimuli. As such, DNA methylation functions as a powerful and dynamic regulator of gene expression. The study of neuroepigenetics has revealed a variety of physiological and pathological states that are associated with both global and gene-specific changes in DNA methylation. Specifically, striking correlations between changes in gene expression and DNA methylation exist in neuropsychiatric and neurodegenerative disorders, during synaptic plasticity, and following CNS injury. However, as the field of neuroepigenetics continues to expand its understanding of the role of DNA methylation in CNS physiology, delineating causal relationships in regards to changes in gene expression and DNA methylation are essential. Moreover, in regards to the larger field of neuroscience, the presence of vast region and cell-specific differences requires techniques that address these variances when studying the transcriptome, proteome, and epigenome. Here we describe FACS sorting of cortical astrocytes that allows for subsequent examination of a both RNA transcription and DNA methylation. Furthermore, we detail a technique to examine DNA methylation, methylation sensitive high resolution melt analysis (MS-HRMA) as well as a luciferase promoter assay. Through the use of these combined techniques one is able to not only explore correlative changes between DNA methylation and gene expression, but also directly assess if changes in the DNA methylation status of a given gene region are sufficient to affect transcriptional activity.

  20. Insecticidal and acetylcholine esterase inhibition activity of Asteraceae plant essential oils and their constituents against adults of the German cockroach (Blattella germanica).

    Science.gov (United States)

    Yeom, Hwa-Jeong; Jung, Chan-Sik; Kang, Jaesoon; Kim, Junheon; Lee, Jae-Hyeon; Kim, Dong-Soo; Kim, Hyun-Seok; Park, Pil-Sun; Kang, Kyu-Suk; Park, Il-Kwon

    2015-03-04

    The fumigant and contact toxicities of 16 Asteraceae plant essential oils and their constituents against adult male and female Blattella germanica were examined. In a fumigant toxicity test, tarragon oil exhibited 100% and 90% fumigant toxicity against adult male German cockroaches at 5 and 2.5 mg/filter paper, respectively. Fumigant toxicities of Artemisia arborescens and santolina oils against adult male German cockroaches were 100% at 20 mg/filter paper, but were reduced to 60% and 22.5% at 10 mg/filter paper, respectively. In contact toxicity tests, tarragon and santolina oils showed potent insecticidal activity against adult male German cockroaches. Components of active oils were analyzed using gas chromatography, gas chromatography-mass spectrometry, or nuclear magnetic resonance spectrometer. Among the identified compounds from active essential oils, estragole demonstrated potent fumigant and contact toxicity against adult German cockroaches. β-Phellandrene exhibited inhibition of male and female German cockroach acetylcholinesterase activity with IC50 values of 0.30 and 0.28 mg/mL, respectively.

  1. Lipase and esterase: to what extent can this classification be applied accurately?

    Directory of Open Access Journals (Sweden)

    Danielle Branta Lopes

    2011-09-01

    Full Text Available Enzyme technology is an ever-growing field of knowledge and, in recent years, this technology has raised renewed interest, due to the search for new paradigms in several productive processes. Lipases, esterases and cutinases are enzymes used in a wide range of processes involving synthesis and hydrolysis reactions. The objective of this work was to investigate and compare the specific lipase and esterase activities of five enzymes - four already classified as lipases and one classified as cutinase - in the presence of natural and synthetic substrates. All tested enzymes presented both esterase and lipase specific activities. The highest specific esterase activity was observed for Aspergillus 1068 lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate, while the highest specific lipase activity was observed for Geotrichum sp. lipase in natural substrate and for F. oxysporum cutinase in synthetic substrate. These results display some interface-independent lipolytic activity for all lipases tested. This is in accordance with the rationale that a new and broader definition of lipases may be necessary.

  2. Impacts of Activated Carbon Amendment on Hg Methylation, Demethylation and Microbial Activity in Marsh Soils

    Science.gov (United States)

    Gilmour, C. C.; Ghosh, U.; Santillan, E. F. U.; Soren, A.; Bell, J. T.; Butera, D.; McBurney, A. W.; Brown, S.; Henry, E.; Vlassopoulos, D.

    2015-12-01

    In-situ sorbent amendments are a low-impact approach for remediation of contaminants in sediments, particular in habitats like wetlands that provide important ecosystem services. Laboratory microcosm trials (Gilmour et al. 2013) and early field trials show that activated carbon (AC) can effectively increase partitioning of both inorganic Hg and methylmercury to the solid phase. Sediment-water partitioning can serve as a proxy for Hg and MeHg bioavailability in soils. One consideration in using AC in remediation is its potential impact on organisms. For mercury, a critical consideration is the potential impact on net MeHg accumulation and bioavailability. In this study, we specifically evaluated the impact of AC on rates of methylmercury production and degradation, and on overall microbial activity, in 4 different Hg-contaminated salt marsh soils. The study was done over 28 days in anaerobic, sulfate-reducing slurries. A double label of enriched mercury isotopes (Me199Hg and inorganic 201Hg) was used to separately follow de novo Me201Hg production and Me199Hg degradation. AC amendments decreased both methylation and demethylation rate constants relative to un-amended controls, but the impact on demethylation was stronger. The addition of 5% (dry weight) regenerated AC to soil slurries drove demethylation rate constants to nearly zero; i.e. MeHg sorption to AC almost totally blocked its degradation. The net impact was increased solid phase MeHg concentrations in some of the soil slurries with the highest methylation rate constants. However, the net impact of AC amendments was to increase MeHg (and inorganic Hg) partitioning to the soil phase and decrease concentrations in the aqueous phase. AC significantly decreased aqueous phase inorganic Hg and MeHg concentrations after 28 days. Overall, the efficacy of AC in reducing aqueous MeHg was highest in the soils with the highest MeHg concentrations. The AC addition did not significantly impact microbial activity, as

  3. Geissoschizine methyl ether N-oxide, a new alkaloid with antiacetylcholinesterase activity from Uncaria rhynchophylla.

    Science.gov (United States)

    Jiang, Wei-Wei; Su, Jia; Wu, Xing-De; He, Juan; Peng, Li-Yan; Cheng, Xiao; Zhao, Qin-Shi

    2015-01-01

    Geissoschizine methyl ether N-oxide, a new oxindole alkaloid, along with 14 known alkaloids, was isolated from the aerial part of Uncaria rhynchophylla. Their structures were identified by comprehensive spectral methods, including 2D NMR experiments, and confirmed by comparing with the literature data. In vitro acetylcholinesterase (AChE) inhibitory activity assay showed that the new compound exhibited anti-AChE activity with IC₅₀ value of 23.4 μM.

  4. Methylation-Dependent Activation of CDX1 through NF-κB

    Science.gov (United States)

    Rau, Tilman T.; Rogler, Anja; Frischauf, Myrjam; Jung, Andreas; Konturek, Peter C.; Dimmler, Arno; Faller, Gerhard; Sehnert, Bettina; El-Rifai, Wael; Hartmann, Arndt; Voll, Reinhard E.; Schneider-Stock, Regine

    2013-01-01

    The caudal homeobox factor 1 (CDX1) is an essential transcription factor for intestinal differentiation. Its aberrant expression in intestinal metaplasia of the upper gastrointestinal tract is a hallmark within the gastritis-metaplasia-carcinoma sequence. CDX1 expression is influenced by certain pathways, such as Wnt, Ras, or NF-κB signaling; however, these pathways alone cannot explain the transient expression of CDX1 in intestinal metaplasia or the molecular inactivation mechanism of its loss in cases of advanced gastric cancer. In this study, we investigated the epigenetic inactivation of CDX1 by promoter methylation, as well as the functional link of CDX1 promoter methylation to the inflammatory NF-κB signaling pathway. We identified methylation-dependent NF-κB binding to the CDX1 promoter and quantified it using competitive electrophoretic mobility shift assays and chromatin immunoprecipitation. A methylated CDX1 promoter was associated with closed chromatin structure, reduced NF-κB binding, and transcriptional silencing. Along the gastritis-metaplasia-carcinoma sequence, we observed a biphasic pattern of tumor necrosis factor-α (TNF-α) protein expression and an inverse biphasic pattern of CDX1 promoter methylation; both are highly consistent with CDX1 protein expression. The stages of hyper-, hypo-, and hyper-methylation patterns of the CDX1 promoter were inversely correlated with the NF-κB signaling activity along this sequence. In conclusion, these functionally interacting events drive CDX1 expression and contribute to intestinal metaplasia, epithelial dedifferentiation, and carcinogenesis in the human stomach. PMID:22749770

  5. Human active X-specific DNA methylation events showing stability across time and tissues

    Science.gov (United States)

    Joo, Jihoon Eric; Novakovic, Boris; Cruickshank, Mark; Doyle, Lex W; Craig, Jeffrey M; Saffery, Richard

    2014-01-01

    The phenomenon of X chromosome inactivation in female mammals is well characterised and remains the archetypal example of dosage compensation via monoallelic expression. The temporal series of events that culminates in inactive X-specific gene silencing by DNA methylation has revealed a ‘patchwork' of gene inactivation along the chromosome, with approximately 15% of genes escaping. Such genes are therefore potentially subject to sex-specific imbalance between males and females. Aside from XIST, the non-coding RNA on the X chromosome destined to be inactivated, very little is known about the extent of loci that may be selectively silenced on the active X chromosome (Xa). Using longitudinal array-based DNA methylation profiling of two human tissues, we have identified specific and widespread active X-specific DNA methylation showing stability over time and across tissues of disparate origin. Our panel of X-chromosome loci subject to methylation on Xa reflects a potentially novel mechanism for controlling female-specific X inactivation and sex-specific dimorphisms in humans. Further work is needed to investigate these phenomena. PMID:24713664

  6. Kinetic modeling of the purging of activated carbon after short term methyl iodide loading

    International Nuclear Information System (INIS)

    Friedrich, V.; Lux, I.

    1991-01-01

    A bimolecular reaction model containing the physico-chemical parameters of the adsorption and desorption was developed earlier to describe the kinetics of methyl iodide retention by activated carbon adsorber. Both theoretical model and experimental investigations postulated constant upstream methyl iodide concentration till the maximum break-through. The work reported here includes the extension of the theoretical model to the general case when the concentration of the challenging gas may change in time. The effect of short term loading followed by purging with air, and an impulse-like increase in upstream gas concentration has been simulated. The case of short term loading and subsequent purging has been experimentally studied to validate the model. The investigations were carried out on non-impregnated activated carbon. A 4 cm deep carbon bed had been challenged by methyl iodide for 30, 90, 120 and 180 min and then purged with air, downstream methyl iodide concentration had been measured continuously. The main characteristics of the observed downstream concentration curves (time and slope of break-through, time and amplitude of maximum values) showed acceptable agreement with those predicted by the model

  7. Methyl Salicylate Level Increase in Flax after Fusarium oxysporum Infection Is Associated with Phenylpropanoid Pathway Activation.

    Science.gov (United States)

    Boba, Aleksandra; Kostyn, Kamil; Kostyn, Anna; Wojtasik, Wioleta; Dziadas, Mariusz; Preisner, Marta; Szopa, Jan; Kulma, Anna

    2016-01-01

    Flax ( Linum usitatissimum ) is a crop plant valued for its oil and fiber. Unfortunately, large losses in cultivation of this plant are caused by fungal infections, with Fusarium oxysporum being one of its most dangerous pathogens. Among the plant's defense strategies, changes in the expression of genes of the shikimate/phenylpropanoid/benzoate pathway and thus in phenolic contents occur. Among the benzoates, salicylic acid, and its methylated form methyl salicylate play an important role in regulating plants' response to stress conditions. Upon treatment of flax plants with the fungus we found that methyl salicylate content increased (4.8-fold of the control) and the expression profiles of the analyzed genes suggest that it is produced most likely from cinnamic acid, through the β-oxidative route. At the same time activation of some genes involved in lignin and flavonoid biosynthesis was observed. We suggest that increased methyl salicylate biosynthesis during flax response to F. oxysporum infection may be associated with phenylpropanoid pathway activation.

  8. Distribution and substrate specificity of esterases in the housefly, Musca domestica L.

    NARCIS (Netherlands)

    Asperen, K. van

    1959-01-01

    Housefly homogenates perform high cholinesterase and ali-esterase activity. Warburg-manometric studies show that acetylcholine, acetyl-β-methylcholine, butyrylcholine, and benzoylcholine are exclusively hydrolysed by a cholinesterase, the properties of which are more or less comparable to those of

  9. Non-specific esterases and esterproteases in masticatory muscles from the muscular dystrophic mouse

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D; Vilmann, H

    1989-01-01

    With the aid of histochemical and electrophoretic techniques activities for esterase and esterprotease were investigated in the digastric and masseter muscles from normal and dystrophic mice. The substrates used were alpha-naphthyl acetate and N-acetyl-L-alanine alpha-naphthyl ester. According...

  10. An Aspergillus oryzae acetyl xylan esterase: molecular cloning and characteristics of recombinant enzyme expressed in Pichia pastoris.

    Science.gov (United States)

    Koseki, Takuya; Miwa, Yozo; Akao, Takeshi; Akita, Osamu; Hashizume, Katsumi

    2006-02-10

    We screened 20,000 clones of an expressed sequence tag (EST) library from Aspergillus oryzae (http://www.nrib.go.jp/ken/EST/db/index.html) and obtained one cDNA clone encoding a protein with similarity to fungal acetyl xylan esterase. We also cloned the corresponding gene, designated as Aoaxe, from the genomic DNA. The deduced amino acid sequence consisted of a putative signal peptide of 31-amino acids and a mature protein of 276-amino acids. We engineered Aoaxe for heterologous expression in P. pastoris. Recombinant AoAXE (rAoAXE) was secreted by the aid of fused alpha-factor secretion signal peptide and accumulated as an active enzyme in the culture medium to a final level of 190 mg/l after 5 days. Purified rAoAXEA before and after treatment with endoglycosidase H migrated by SDS-PAGE with a molecular mass of 31 and 30 kDa, respectively. Purified rAoAXE displayed the greatest hydrolytic activity toward alpha-naphthylacetate (C2), lower activity toward alpha-naphthylpropionate (C3) and no detectable activity toward acyl-chain substrates containing four or more carbon atoms. The recombinant enzyme catalyzed the release of acetic acid from birchwood xylan. No activity was detectable using methyl esters of ferulic, caffeic or sinapic acids. rAoAXE was thermolabile in comparison to other AXEs from Aspergillus.

  11. Chlropyrifos-methyl shows anti-androgenic activity without estrogenic activity in rats

    International Nuclear Information System (INIS)

    Kang, Hwan Goo; Jeong, Sang Hee; Cho, Joon Hyoung; Kim, Dong Gyu; Park, Jong Myung; Cho, Myung Haing

    2004-01-01

    Chlorpyrifos-methyl (CPM), an organophosphate insecticide, widely used for grain storage and agriculture, has been suspected as endocrine disrupter by a few in vitro studies. This study was performed to investigate the (anti-) estrogenicity and (anti-) androgenicity of CPM in vivo using immature rat uterotrophic assay and rat Hershberger assay. CPM with or without 17β-estradiol were administered to 20 days old female rats to investigate its (anti-) estrogenic activity. Uterine and vaginal weight, uterine epithelial cell height were not affected by the treatment of CPM (2, 10, 50, 250 mg/kg). CPM 250 mg/kg potentiated relative vagina weight in 17β-estradiol treated immature female rats without any changing of uterine weight. Relative liver weight was increased with decrease of body weight by CPM 250 mg/kg treatment. Uterine cell proliferation tested with bromodeoxyuridine labeling index was not observed in CPM treated rats. CPM with or without testosterone propionate were administered to castrated rat of 51 days old for 10 days to investigate the (anti-)androgenic activity,. The weight of relative and absolute androgen-dependent accessory sex organs; seminal vesicle with coagulating glands (SV/CG), ventral prostate gland (VP), glans penis (GP), levator ani plus bulbocarvernosus muscle (LABC) and Cowper's gland (CG,) were unchanged by the treatment of CPM alone. While CPM induced the increase of relative adrenal gland weight, CPM 50 mg/kg decreased the weights of CV/CG, VP, CG and LABC without change of GP without changing of GP when it was treated with TP. In conclusion, CPM dose not show estrogenic and anti-estrogenic activity in immature female rats, but it represents anti-androgenic activity by inhibition of the TP-stimulated increase of the weight of accessory sex organs

  12. Active transport, substrate specificity, and methylation of Hg(II) in anaerobic bacteria

    Science.gov (United States)

    Schaefer, Jeffra K.; Rocks, Sara S.; Zheng, Wang; Liang, Liyuan; Gu, Baohua; Morel, François M. M.

    2011-01-01

    The formation of methylmercury (MeHg), which is biomagnified in aquatic food chains and poses a risk to human health, is effected by some iron- and sulfate-reducing bacteria (FeRB and SRB) in anaerobic environments. However, very little is known regarding the mechanism of uptake of inorganic Hg by these organisms, in part because of the inherent difficulty in measuring the intracellular Hg concentration. By using the FeRB Geobacter sulfurreducens and the SRB Desulfovibrio desulfuricans ND132 as model organisms, we demonstrate that Hg(II) uptake occurs by active transport. We also establish that Hg(II) uptake by G. sulfurreducens is highly dependent on the characteristics of the thiols that bind Hg(II) in the external medium, with some thiols promoting uptake and methylation and others inhibiting both. The Hg(II) uptake system of D. desulfuricans has a higher affinity than that of G. sulfurreducens and promotes Hg methylation in the presence of stronger complexing thiols. We observed a tight coupling between Hg methylation and MeHg export from the cell, suggesting that these two processes may serve to avoid the build up and toxicity of cellular Hg. Our results bring up the question of whether cellular Hg uptake is specific for Hg(II) or accidental, occurring via some essential metal importer. Our data also point at Hg(II) complexation by thiols as an important factor controlling Hg methylation in anaerobic environments. PMID:21555571

  13. Adsorption of methyl orange using activated carbon prepared from lignin by ZnCl2 treatment

    Science.gov (United States)

    Mahmoudi, K.; Hamdi, N.; Kriaa, A.; Srasra, E.

    2012-08-01

    Lignocellulosic materials are good and cheap precursors for the production of activated carbon. In this study, activated carbons were prepared from the lignin at different temperatures (200 to 500°C) by ZnCl2. The effects influencing the surface area of the resulting activated carbon are activation temperature, activation time and impregnation ratio. The optimum condition, are found an impregnation ratio of 2, an activation temperature of 450°C, and an activation time of 2 h. The results showed that the surface area and micropores volume of activated carbon at the experimental conditions are achieved to 587 and 0.23 cm3 g-1, respectively. The adsorption behavior of methyl orange dye from aqueous solution onto activated lignin was investigated as a function of equilibrium time, pH and concentration. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms. A maximum adsorption capacity of 300 mg g-1 of methyl orange by activated carbon was achieved.

  14. Overexpression of Human-Derived DNMT3A Induced Intergenerational Inheritance of Active DNA Methylation Changes in Rat Sperm

    Directory of Open Access Journals (Sweden)

    Xiaoguo Zheng

    2017-12-01

    Full Text Available DNA methylation is the major focus of studies on paternal epigenetic inheritance in mammals, but most previous studies about inheritable DNA methylation changes are passively induced by environmental factors. However, it is unclear whether the active changes mediated by variations in DNA methyltransferase activity are heritable. Here, we established human-derived DNMT3A (hDNMT3A transgenic rats to study the effect of hDNMT3A overexpression on the DNA methylation pattern of rat sperm and to investigate whether this actively altered DNA methylation status is inheritable. Our results revealed that hDNMT3A was overexpressed in the testis of transgenic rats and induced genome-wide alterations in the DNA methylation pattern of rat sperm. Among 5438 reliable loci identified with 64 primer-pair combinations using a methylation-sensitive amplification polymorphism method, 28.01% showed altered amplified band types. Among these amplicons altered loci, 68.42% showed an altered DNA methylation status in the offspring of transgenic rats compared with wild-type rats. Further analysis based on loci which had identical DNA methylation status in all three biological replicates revealed that overexpression of hDNMT3A in paternal testis induced hypermethylation in sperm of both genotype-negative and genotype-positive offspring. Among the differentially methylated loci, 34.26% occurred in both positive and negative offspring of transgenic rats, indicating intergenerational inheritance of active DNA methylation changes in the absence of hDNM3A transmission. Furthermore, 75.07% of the inheritable loci were hyper-methylated while the remaining were hypomethylated. Distribution analysis revealed that the DNA methylation variations mainly occurred in introns and intergenic regions. Functional analysis revealed that genes related to differentially methylated loci were involved in a wide range of functions. Finally, this study demonstrated that active DNA methylation

  15. Stress-related methylation of the catechol-O-methyltransferase Val 158 allele predicts human prefrontal cognition and activity.

    Science.gov (United States)

    Ursini, Gianluca; Bollati, Valentina; Fazio, Leonardo; Porcelli, Annamaria; Iacovelli, Luisa; Catalani, Assia; Sinibaldi, Lorenzo; Gelao, Barbara; Romano, Raffaella; Rampino, Antonio; Taurisano, Paolo; Mancini, Marina; Di Giorgio, Annabella; Popolizio, Teresa; Baccarelli, Andrea; De Blasi, Antonio; Blasi, Giuseppe; Bertolino, Alessandro

    2011-05-04

    DNA methylation at CpG dinucleotides is associated with gene silencing, stress, and memory. The catechol-O-methyltransferase (COMT) Val(158) allele in rs4680 is associated with differential enzyme activity, stress responsivity, and prefrontal activity during working memory (WM), and it creates a CpG dinucleotide. We report that methylation of the Val(158) allele measured from peripheral blood mononuclear cells (PBMCs) of Val/Val humans is associated negatively with lifetime stress and positively with WM performance; it interacts with stress to modulate prefrontal activity during WM, such that greater stress and lower methylation are related to reduced cortical efficiency; and it is inversely related to mRNA expression and protein levels, potentially explaining the in vivo effects. Finally, methylation of COMT in prefrontal cortex and that in PBMCs of rats are correlated. The relationship of methylation of the COMT Val(158) allele with stress, gene expression, WM performance, and related brain activity suggests that stress-related methylation is associated with silencing of the gene, which partially compensates the physiological role of the high-activity Val allele in prefrontal cognition and activity. Moreover, these results demonstrate how stress-related DNA methylation of specific functional alleles impacts directly on human brain physiology beyond sequence variation.

  16. Microalgal fatty acid methyl ester a new source of bioactive compounds with antimicrobial activity

    OpenAIRE

    Arumugham Suresh; Ramasamy Praveenkumar; Ramasamy Thangaraj; Felix Lewis Oscar; Edachery Baldev; Dharumadurai Dhanasekaran; Nooruddin Thajuddin

    2014-01-01

    Objective: To evaluate fatty acid composition and the antimicrobial activity of the major fraction of fatty acid methyl ester (FAME) extracts from three microalgae collected from freshwater lakes in Theni District, Tamil Nadu, India. Methods: Antimicrobial study was carried out by well diffusion method against bacterial as well as fungal pathogens such as Escherichia coli, Staphylococcus aureus, Enterobacter sp., Klebsiella sp., Salmonella typhi, Fusarium sp., Cryptococcus sp.,...

  17. Synthesis and antiproliferative activity of diethyl 5- acetyl-4-methyl- 6 ...

    African Journals Online (AJOL)

    Diethyl 5-acetyl-4-methyl-6-(2-fluorophenylimino)-6H-thiopyran-2,3-dicarboxylate (3TM) was synthesized and the antiproliferative activity of 3TM is reported here. Compound 3TM inhibits the growth of human colon cancer HCT-15 with an IC50 value of 4.5 μM and breast cancer MCF-7 with an IC50 value of 7 μM in a ...

  18. Agonists and partial agonists of rhodopsin: retinal polyene methylation affects receptor activation.

    Science.gov (United States)

    Vogel, Reiner; Lüdeke, Steffen; Siebert, Friedrich; Sakmar, Thomas P; Hirshfeld, Amiram; Sheves, Mordechai

    2006-02-14

    Using Fourier transform infrared (FTIR) difference spectroscopy, we have studied the impact of sites and extent of methylation of the retinal polyene with respect to position and thermodynamic parameters of the conformational equilibrium between the Meta I and Meta II photoproducts of rhodopsin. Deletion of methyl groups to form 9-demethyl and 13-demethyl analogues, as well as addition of a methyl group at C10 or C12, shifted the Meta I/Meta II equilibrium toward Meta I, such that the retinal analogues behaved like partial agonists. This equilibrium shift resulted from an apparent reduction of the entropy gain of the transition of up to 65%, which was only partially offset by a concomitant reduction of the enthalpy increase. The analogues produced Meta II photoproducts with relatively small alterations, while their Meta I states were significantly altered, which accounted for the aberrant transitions to Meta II. Addition of a methyl group at C14 influenced the thermodynamic parameters but had little impact on the position of the Meta I/Meta II equilibrium. Neutralization of the residue 134 in the E134Q opsin mutant increased the Meta II content of the 13-demethyl analogue, but not of the 9-demethyl analogue, indicating a severe impairment of the allosteric coupling between the conserved cytoplasmic ERY motif involved in proton uptake and the Schiff base/Glu 113 microdomain in the 9-demethyl analogue. The 9-methyl group appears therefore essential for the correct positioning of retinal to link protonation of the cytoplasmic motif with protonation of Glu 113 during receptor activation.

  19. New Synthesis and Antiparasitic Activity of Model 5-Aryl-1-methyl-4-nitroimidazoles

    Directory of Open Access Journals (Sweden)

    Mustafa M. El-Abadelah

    2009-07-01

    Full Text Available A number of 5-aryl-1-methyl-4-nitroimidazoles 5a-f have been synthesized in good yields by the Suzuki coupling reaction between 5-chloro-1-methyl-4-nitroimidazole (3 and arylboronic acids 4a-f, aided by dichlorobis-(triphenylphosphinepalladium(II, K2CO3, and tetrabutylammonium bromide in water at 70-80 °C. Compounds 5a-f were characterized by elemental analysis, NMR and MS spectral data. On the basis of in vitro screening data, 5-(3-chlorophenyl-1-methyl-4-nitro-1H-imidazole (5fexhibited potent lethal activity against Entamoeba histolytica and Giardia intestinalis with IC50 = 1.47 µM/mL, a value lower by a factor of two than that of the standard drug, metronidazole. The boosted activity of 5f was not accompanied by any increased cytotoxicity.The rest of the series also exhibited potent antiparasitic activity with IC50 valuesin the 1.72-4.43 µM/mL range. The cytotoxicity of the derivatives 5c and 5e was increased compared to the precursor compound, metronidazole, although they remain non-cytotoxic at concentrations much higher than the antiparasitic concentration of the two derivatives.

  20. New synthesis and antiparasitic activity of model 5-aryl-1-methyl-4-nitroimidazoles.

    Science.gov (United States)

    Saadeh, Haythem A; Mosleh, Ibrahim M; El-Abadelah, Mustafa M

    2009-07-27

    A number of 5-aryl-1-methyl-4-nitroimidazoles 5a-f have been synthesized in good yields by the Suzuki coupling reaction between 5-chloro-1-methyl-4-nitroimidazole (3) and arylboronic acids 4a-f, aided by dichlorobis-(triphenylphosphine)palladium(II), K(2)CO(3, )and tetrabutylammonium bromide in water at 70-80 degrees C. Compounds 5a-f were characterized by elemental analysis, NMR and MS spectral data. On the basis of in vitro screening data, 5-(3-chlorophenyl)-1-methyl-4-nitro-1H-imidazole (5f) exhibited potent lethal activity against Entamoeba histolytica and Giardia intestinalis with IC(50) = 1.47 microM/mL, a value lower by a factor of two than that of the standard drug, metronidazole. The boosted activity of 5f was not accompanied by any increased cytotoxicity.The rest of the series also exhibited potent antiparasitic activity with IC(50 ) values in the 1.72-4.43 microM/mL range. The cytotoxicity of the derivatives 5c and 5e was increased compared to the precursor compound, metronidazole, although they remain non-cytotoxic at concentrations much higher than the antiparasitic concentration of the two derivatives.

  1. Proteinase activity in cell nuclei of rats exposed to γ-radiation and methyl nitrosourea

    International Nuclear Information System (INIS)

    Malakhova, L.V.; Surkenova, G.N.; Gaziev, A.I.

    1990-01-01

    Activity of nuclear proteinases in blood and liver cells of rats exposed to whole-body γ-irradiation (10 Gy) has been comparatively studied by the capacity of splitting the caseic substrate. Proteinase activity in nuclei of irradiated rat leukocytes was shown to increase by 2.5 times and to gradually decrease after 48 h reaching 150-160% as compared to the control. Two hours following a single injection of methyl nitrosourea the alteration in the activity of proteinases in nuclei of rat hepatocytes and leukocytes was different from the alteration of this index after γ-irradiation

  2. Study of desorption of methyl iodide from activated carbon impregnated by TEDA

    International Nuclear Information System (INIS)

    Yue Longqing; Luo Deli; Yue Ziyu

    2013-01-01

    The capability of iodine retention is an important parameter of solid sorbent, iodine could be desorbed from activated carbon once the parameter doesn't meet requirement. This work discussed the effects of nitrogen flow rate, dipping in water, temperature and K + on the iodine retention. The results show, the quantities of iodine released increase to 3.15 times when nitrogen flow rates increase from 0.1 m 3 /h to 1.5 m 3 /h; methyl iodine molecules are desorbed after half of an hour's dipping in water with no notable change observed thereafter to the desorption capacity at l.5 h, 2 h, 3 h, 4 h respectively; there was no release of iodine below 80 ℃; K + play a positive role for retention of iodine species; and that the quantities of methyl iodine released with 0.06 g KCl account for 56% of that without KCl. (authors)

  3. Synthesis of 1-isopropyl-3-acyl-5-methyl-benzimidazolone Derivatives and Their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Shaopeng Wei

    2013-03-01

    Full Text Available A series of N-acylated analogues of 1-isopropyl-3-acyl-5-methyl-benzimidazolone were synthesized. Bioassay results indicated that analogues 5-07 and 5-19 exhibited the most potency against Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Analogues 5-02, 5-07, 5-12, 5-15, 5-19, 5-20 and 5-25 could effectively inhibit the spore germination of Botrytis cinerea. The relationship between structure and their antimicrobial activity (SAR has also been discussed according to aliphatic acids and aromatic acids derivatives, respectively. This implied that the N-acylated derivatives of 5-methyl-benzimidazolone might be potential antimicrobial agents.

  4. Crystal Structure and Substrate Specificity Modification of Acetyl Xylan Esterase from Aspergillus luchuensis.

    Science.gov (United States)

    Komiya, Dai; Hori, Akane; Ishida, Takuya; Igarashi, Kiyohiko; Samejima, Masahiro; Koseki, Takuya; Fushinobu, Shinya

    2017-10-15

    Acetyl xylan esterase (AXE) catalyzes the hydrolysis of the acetyl bonds present in plant cell wall polysaccharides. Here, we determined the crystal structure of AXE from Aspergillus luchuensis ( Al AXEA), providing the three-dimensional structure of an enzyme in the Esterase_phb family. Al AXEA shares its core α/β-hydrolase fold structure with esterases in other families, but it has an extended central β-sheet at both its ends and an extra loop. Structural comparison with a ferulic acid esterase (FAE) from Aspergillus niger indicated that Al AXEA has a conserved catalytic machinery: a catalytic triad (Ser119, His259, and Asp202) and an oxyanion hole (Cys40 and Ser120). Near the catalytic triad of A lAXEA, two aromatic residues (Tyr39 and Trp160) form small pockets at both sides. Homology models of fungal FAEs in the same Esterase_phb family have wide pockets at the corresponding sites because they have residues with smaller side chains (Pro, Ser, and Gly). Mutants with site-directed mutations at Tyr39 showed a substrate specificity similar to that of the wild-type enzyme, whereas those with mutations at Trp160 acquired an expanded substrate specificity. Interestingly, the Trp160 mutants acquired weak but significant type B-like FAE activity. Moreover, the engineered enzymes exhibited ferulic acid-releasing activity from wheat arabinoxylan. IMPORTANCE Hemicelluloses in the plant cell wall are often decorated by acetyl and ferulic acid groups. Therefore, complete and efficient degradation of plant polysaccharides requires the enzymes for cleaving the side chains of the polymer. Since the Esterase_phb family contains a wide array of fungal FAEs and AXEs from fungi and bacteria, our study will provide a structural basis for the molecular mechanism of these industrially relevant enzymes in biopolymer degradation. The structure of the Esterase_phb family also provides information for bacterial polyhydroxyalkanoate depolymerases that are involved in biodegradation of

  5. Estimation of the fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2008-01-01

    The fraction of biologically active methyl tert-butyl ether degraders in reactors is just as important for prediction of removal rates as knowledge of the kinetic parameters. The fraction of biologically active methyl tert-butyl ether degraders in a heterogeneous biomass sample, taken from a packed...... bed reactor, was determined using a batch kinetic based approach. The procedure involved modeling of methyl tert-butyl ether removal rates from batch experiments followed by parameter estimations. It was estimated to be 5-14% (w/w) of the measured volatile suspended solids concentration in the reactor....

  6. Cyclical DNA Methylation and Histone Changes Are Induced by LPS to Activate COX-2 in Human Intestinal Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Tiziana Angrisano

    Full Text Available Bacterial lipopolysaccharide (LPS induces release of inflammatory mediators both in immune and epithelial cells. We investigated whether changes of epigenetic marks, including selected histone modification and DNA methylation, may drive or accompany the activation of COX-2 gene in HT-29 human intestinal epithelial cells upon exposure to LPS. Here we describe cyclical histone acetylation (H3, methylation (H3K4, H3K9, H3K27 and DNA methylation changes occurring at COX-2 gene promoter overtime after LPS stimulation. Histone K27 methylation changes are carried out by the H3 demethylase JMJD3 and are essential for COX-2 induction by LPS. The changes of the histone code are associated with cyclical methylation signatures at the promoter and gene body of COX-2 gene.

  7. Biological activities of essential oils of Endlicheria citriodora, a methyl geranate-rich lauraceae

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Klenicy K.L.; Veiga-Junior, Valdir F., E-mail: valdirveiga@ufam.edu.br [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal do Amazonas, Manaus - AM (Brazil); Pedrosa, Tatiana do Nascimento; Vasconcellos, Marne Carvalho de; Lima, Emerson Silva [Faculdade de Ciencias Farmaceuticas, Universidade Federal do Amazonas, Manaus, AM (Brazil)

    2013-09-01

    The essential oils of branches and leaves of Endlicheria citiodora were obtained by hydrodistillation and analysed using GC-FID, GC-MS and both NMR {sup 13}C and {sup 1}H, resulting in the identification of methyl geranate as major constituent (93%) in both oils. Cytotoxicity, tyrosinase-inhibition and antioxidant activities were studied and characterized. High antioxidant potential (15.52 and 13.53 {mu}g/mL), low cytotoxicity and tyrosinase inhibition (53.85%) were observed. This is the first paper reporting the biological activities and composition of the essential oils of this species. (author)

  8. Biological activities of essential oils of Endlicheria citriodora, a methyl geranate-rich lauraceae

    International Nuclear Information System (INIS)

    Yamaguchi, Klenicy K.L.; Veiga-Junior, Valdir F.; Pedrosa, Tatiana do Nascimento; Vasconcellos, Marne Carvalho de; Lima, Emerson Silva

    2013-01-01

    The essential oils of branches and leaves of Endlicheria citiodora were obtained by hydrodistillation and analysed using GC-FID, GC-MS and both NMR 13 C and 1 H, resulting in the identification of methyl geranate as major constituent (93%) in both oils. Cytotoxicity, tyrosinase-inhibition and antioxidant activities were studied and characterized. High antioxidant potential (15.52 and 13.53 μg/mL), low cytotoxicity and tyrosinase inhibition (53.85%) were observed. This is the first paper reporting the biological activities and composition of the essential oils of this species. (author)

  9. Antifungal and antioxidant activity of fatty acid methyl esters from vegetable oils

    Directory of Open Access Journals (Sweden)

    MARIA E.A. PINTO

    2017-08-01

    Full Text Available ABSTRACT Fatty acid methyl esters (FAMEs were obtained from vegetable oils of soybean, corn and sunflower. The current study was focused on evaluating the antifungal activity of FAMEs mainly against Paracoccidioides spp., as well as testing the interaction of these compounds with commercial antifungal drugs and also their antioxidant potential. FAMEs presented small IC50 values (1.86-9.42 μg/mL. All three FAMEs tested showed antifungal activity against isolates of Paracoccidioides spp. with MIC values ranging from 15.6-500 µg/mL. Sunflower FAMEs exhibited antifungal activity that extended also to other genera, with an MIC of 15.6 μg/mL against Candida glabrata and C. krusei and 31.2 μg/mL against C. parapsilosis. FAMEs exhibited a synergetic effect with itraconazole. The antifungal activity of the FAMEs against isolates of Paracoccidioides spp. is likely due to the presence of methyl linoleate, the major compound present in all three FAMEs. The results obtained indicate the potential of FAMEs as sources for antifungal and antioxidant activity.

  10. Simultaneous measurement of two enzyme activities using infrared spectroscopy: A comparative evaluation of PARAFAC, TUCKER and N-PLS modeling

    DEFF Research Database (Denmark)

    Baum, Andreas; Hansen, Per Waaben; Meyer, Anne S.

    2013-01-01

    multiway methods, namely PARAFAC, TUCKER3 and N-PLS, to establish simultaneous enzyme activity assays for pectin lyase and pectin methyl esterase. Correlation coefficients Rpred2 for prediction test sets are 0.48, 0.96 and 0.96 for pectin lyase and 0.70, 0.89 and 0.89 for pectin methyl esterase......Enzymes are used in many processes to release fermentable sugars for green production of biofuel, or the refinery of biomass for extraction of functional food ingredients such as pectin or prebiotic oligosaccharides. The complex biomasses may, however, require a multitude of specific enzymes which...... are active on specific substrates generating a multitude of products. In this paper we use the plant polymer, pectin, to present a method to quantify enzyme activity of two pectolytic enzymes by monitoring their superimposed spectral evolutions simultaneously. The data is analyzed by three chemometric...

  11. Arabidopsis phyllotaxis is controlled by the methyl-esterification status of cell-wall pectins.

    Science.gov (United States)

    Peaucelle, Alexis; Louvet, Romain; Johansen, Jorunn N; Höfte, Herman; Laufs, Patrick; Pelloux, Jérome; Mouille, Grégory

    2008-12-23

    Plant organs are produced from meristems in a characteristic pattern. This pattern, referred to as phyllotaxis, is thought to be generated by local gradients of an information molecule, auxin. Some studies propose a key role for the mechanical properties of the cell walls in the control of organ outgrowth. A major cell-wall component is the linear alpha-1-4-linked D-GalAp pectic polysaccharide homogalacturonan (HG), which plays a key role in cell-to-cell cohesion. HG is deposited in the cell wall in a highly (70%-80%) methyl-esterified form and is subsequently de-methyl-esterified by pectin methyl-esterases (PME, EC 3.1.1.11). PME activity is itself regulated by endogenous PME inhibitor (PMEI) proteins. PME action modulates cell-wall-matrix properties and plays a role in the control of cell growth. Here, we show that the formation of flower primordia in the Arabidopsis shoot apical meristem is accompanied by the de-methyl-esterification of pectic polysaccharides in the cell walls. In addition, experimental perturbation of the methyl-esterification status of pectins within the meristem dramatically alters the phyllotactic pattern. These results demonstrate that regulated de-methyl-esterification of pectins is a key event in the outgrowth of primordia and possibly also in phyllotactic patterning.

  12. Methyl salicylate is a critical mobile signal for plant systemic acquired resistance.

    Science.gov (United States)

    Park, Sang-Wook; Kaimoyo, Evans; Kumar, Dhirendra; Mosher, Stephen; Klessig, Daniel F

    2007-10-05

    In plants, the mobile signal for systemic acquired resistance (SAR), an organism-wide state of enhanced defense to subsequent infections, has been elusive. By stimulating immune responses in mosaic tobacco plants created by grafting different genetic backgrounds, we showed that the methyl salicylate (MeSA) esterase activity of salicylic acid-binding protein 2 (SABP2), which converts MeSA into salicylic acid (SA), is required for SAR signal perception in systemic tissue, the tissue that does not receive the primary (initial) infection. Moreover, in plants expressing mutant SABP2 with unregulated MeSA esterase activity in SAR signal-generating, primary infected leaves, SAR was compromised and the associated increase in MeSA levels was suppressed in primary infected leaves, their phloem exudates, and systemic leaves. SAR was also blocked when SA methyl transferase (which converts SA to MeSA) was silenced in primary infected leaves, and MeSA treatment of lower leaves induced SAR in upper untreated leaves. Therefore, we conclude that MeSA is a SAR signal in tobacco.

  13. Genome-wide analysis of esterase-like genes in the striped rice stem borer, Chilo suppressalis.

    Science.gov (United States)

    Wang, Baoju; Wang, Ying; Zhang, Yang; Han, Ping; Li, Fei; Han, Zhaojun

    2015-06-01

    The striped rice stem borer, Chilo suppressalis, a destructive pest of rice, has developed high levels of resistance to certain insecticides. Esterases are reported to be involved in insecticide resistance in several insects. Therefore, this study systematically analyzed esterase-like genes in C. suppressalis. Fifty-one esterase-like genes were identified in the draft genomic sequences of the species, and 20 cDNA sequences were derived which encoded full- or nearly full-length proteins. The putative esterase proteins derived from these full-length genes are overall highly diversified. However, key residues that are functionally important including the serine residue in the active site are conserved in 18 out of the 20 proteins. Phylogenetic analysis revealed that most of these genes have homologues in other lepidoptera insects. Genes CsuEst6, CsuEst10, CsuEst11, and CsuEst51 were induced by the insecticide triazophos, and genes CsuEst9, CsuEst11, CsuEst14, and CsuEst51 were induced by the insecticide chlorantraniliprole. Our results provide a foundation for future studies of insecticide resistance in C. suppressalis and for comparative research with esterase genes from other insect species.

  14. Determination of trace elements in poly(methyl methacrylate) by neutron activation analysis

    International Nuclear Information System (INIS)

    Kobayashi, M.

    1979-01-01

    The results are reported of the neutron activation analysis of poly(methyl methacrylate) polymerized with a redox system of chromium (II) acetate and p-chlorobenzyl peroxide in dimethylformamide at 30 0 C. Since the polymer was originally synthesized in experiments for kinetic studies, the results indicate an arbitrary background of purity of polymers obtained in a laboratory. Samples were irradiated for 28m and gamma spectra detected trace amounts of chlorine, aluminum, vanadium, magnesium, manganese, potassium, copper, zinc, sodium, bromine, lanthanum, gold, and chromium. 2 figures, 1 table

  15. Production and partial characterization of alkaline feruloyl esterases by Fusarium oxysporum during submerged batch cultivation

    DEFF Research Database (Denmark)

    Topakas, E.; Christakopoulos, Paul

    2004-01-01

    Production of feruloyl esterases (FAEs) by Fusarium oxysporum was enhanced by optimization of initial pH of the culture medium, the type and concentration of nitrogen and carbon source. Submerged batch cultivation in a laboratory bioreactor (17 1) produced activity at 82 nkat g(-1) dry substrate....... Production of FAE does not therefore, require FA, however, production is diminished by the removal of esterified FA from the growth substrate. Optimal FAE activity was observed at pH 7 and 50 degreesC with 68 and 55% activity at pH 8 and pH 9, respectively. The esterase was fully stable at pH 5-8 and up...

  16. Dampak Hipoksia Sistemik terhadap Malondialdehida, Glial Fibrillary Acidic Protein dan Aktivitas Asetilkolin Esterase Otak Tikus

    Directory of Open Access Journals (Sweden)

    Andriani Andriani

    2016-09-01

    Full Text Available Hipoksia sistemik menyebabkan berkurangnya oksigen dan energi di otak sehingga memicupenglepasan neurotransmiter asetilkolin, meningkatkan radikal bebas dan glial fibrillary acidic protein (GFAPyang berfungsi menjaga kekuatan membran. Tujuan penelitian untuk melihat gambaran adaptasi otak padahipoksia sistemik terhadap fungsi asetilkolin esterase, kerusakan membran sel neuron dan astrosit. Penelitiandilakukan di Laboratorium Biokimia & Biologi Molekuler FK Universitas Indonesia, pada tahun 2013.Penelitian ekperimental ini menggunakan hewan coba tikus spraque dawley yang diinduksi hipoksia sistemikyang diambil jaringan otak bagian korteks dan plasma tikus. Kelompok tikus terdiri atas kelompok kontrol,kelompok perlakuan induksi hipoksia hari ke-1, 3 hari, 5 hari dan hari ke-7. Parameter yang diukur adalahkadar malondialdehida (MDA otak dan plasma, aktivitas spesifik enzim AChE jaringan otak serta kadar GFAPjaringan otak. Hasil menunjukkan bahwa hipoksia sistemik tidak meningkatkankadar MDA otak dan plasma.Induksi hipoksia sistemik meningkatkan aktivitas spesifik enzim AChE dan kadar GFAP jaringan otak secarabermakna. Pada plasma tidak terjadi peningkatan kadar GFAP. Hipoksia sistemik selama hari ke-7 belummenyebabkan kerusakan oksidatif, namun memperlihatkan peningkatan aktivitas AChe dan adaptasi astrositmelalui peningkatan GFAP. Kata kunci: hipoksia, astrosit, glial fibrillary acidic protein, malondialdehida, asetilkolin esterase   Systemic Hypoxia Effect on Rat Brain Malondialdehyde, Glial FibrillaryAcidic Protein, and Acetylcholine Esterase Activity Abstract Sistemic hypoxia causes lack of oxygen and energy in brain that trigger the release of acetylcholine,free radical and Glial fibrillary acidic protein (GFAP, a specific protein in astrocyte cells that act to strenghtenastrocite membrane. The aim of the research was to evaluate the damages of brain in systemic hypoxiathrough activity of acetylcholine esterase, neuron and astrocyte membran

  17. Control of anthracnose disease via increased activity of defence related enzymes in 'Hass' avocado fruit treated with methyl jasmonate and methyl salicylate.

    Science.gov (United States)

    Glowacz, Marcin; Roets, Nico; Sivakumar, Dharini

    2017-11-01

    Development of anthracnose disease caused by Colletotrichum gloeosporioides Penz. is one of the major issues within the avocado supply chain. Exposure to methyl jasmonate (MeJA) and methyl salicylate (MeSA) vapours at 10 and 100µmoll -1 was investigated as an alternative solution to commercial fungicide - prochloraz® that is currently being used by the industry. The incidence of anthracnose disease was found to be significantly reduced in 'Hass' avocado fruit treated with MeJA or MeSA vapours, especially at 100μmoll -1 . The mechanism involved enhanced activity of defence related enzymes, i.e. chitinase, β-1,3-glucanase and PAL, and higher content of epicatechin. Copyright © 2017. Published by Elsevier Ltd.

  18. A Novel Halotolerant Thermoalkaliphilic Esterase from Marine Bacterium Erythrobacter seohaensis SW-135

    Directory of Open Access Journals (Sweden)

    Ying-Yi Huo

    2017-11-01

    Full Text Available A novel esterase gene, e69, was cloned from Erythrobacter seohaensis SW-135, which was isolated from a tidal flat sediment of the Yellow Sea in Korea. This gene is 825 bp in length and codes for a 29.54 kDa protein containing 274 amino acids. Phylogenetic analysis showed that E69 is a new member of the bacterial lipolytic enzyme family IV. This enzyme exhibited the highest level of activity toward p-nitrophenyl (NP butyrate but little or no activity toward the other p-NP esters tested. The optimum temperature and pH of the catalytic activity of E69 were 60°C and pH 10.5, respectively. The enzyme exhibited stable activity over a wide range of alkaline pH values (7.5–9.5. In addition, E69 was found to be a halotolerant esterase as it exhibited the highest hydrolytic activity in the presence of 0.5 M NaCl and was still active in the presence of 3 M NaCl. Moreover, it possessed some degree of tolerance to Triton X-100 and several organic solvents. Through homology modeling and comparison with other esterases, it was suggested that the absence of the cap domain and its narrow substrate-binding pocket might be responsible for its narrow substrate specificity. Sequence and structural analysis results suggested that its high ratio of negatively to positively charged residues, large hydrophobic surface area, and negative electrostatic potential on the surface may be responsible for its alkaline adaptation. The results of this study provide insight into marine alkaliphilic esterases, and the unique properties of E69 make it a promising candidate as a biocatalyst for industrial applications.

  19. Purification and biochemical characterization of feruloyl esterases from Aspergillus terreus MTCC 11096.

    Science.gov (United States)

    Kumar, C Ganesh; Kamle, Avijeet; Kamal, Ahmed

    2013-01-01

    Aspergillus terreus MTCC 11096 isolated from the soils of agricultural fields cultivating sweet sorghum was previously identified to produce feruloyl esterases (FAEs). The enzymes responsible for feruloyl esterase activity were purified to homogeneity and named as AtFAE-1, AtFAE-2, and AtFAE-3. The enzymes were monomeric having molecular masses of 74, 23 and 36 kDa, respectively. Active protein bands were identified by a developed pH-dependent zymogram on native PAGE. The three enzymes exhibited variation in pH tolerance ranging between pH 5-8 and thermostability of up to 55°C. Inhibition studies revealed that the serine residue was essential for feruloyl esterase activity; moreover aspartyl and glutamyl residues are not totally involved at the active site. Metal ions such as Ca(2+), K(+), and Mg(2+) stabilized the enzyme activity for all three FAEs. Kinetic data indicated that all three enzymes showed catalytic efficiencies (k(cat) /K(m)) against different synthesized alkyl and aryl esters indicating their broad substrate specificity. The peptide mass fingerprinting by MALDI/TOF-MS analysis and enzyme affinity toward methoxy and hydroxy substituents on the benzene ring revealed that the AtFAE-1 belonged to type A while AtFAE-2 and AtFAE-3 were type C FAE. The FAEs could release 65 to 90% of ferulic acid from agrowaste substrates in the presence of xylanase. © 2013 American Institute of Chemical Engineers.

  20. Crystallization and preliminary X-ray diffraction analysis of the glucuronoyl esterase catalytic domain from Hypocrea jecorina

    International Nuclear Information System (INIS)

    Wood, S. J.; Li, X.-L.; Cotta, M. A.; Biely, P.; Duke, N. E. C.; Schiffer, M.; Pokkuluri, P. R.

    2008-01-01

    The catalytic domain of the glucuronoyl esterase from H. jecorina was overexpresssed, purified and crystallized in space group P2 1 2 1 2 1 . X-ray diffraction data were collected to 1.9 Å resolution. The catalytic domain of the glucuronoyl esterase from Hypocrea jecorina (anamorph Trichoderma reesei) was overexpresssed, purified and crystallized by the sitting-drop vapor-diffusion method using 1.4 M sodium/potassium phosphate pH 6.9. The crystals belonged to space group P2 1 2 1 2 1 and X-ray diffraction data were collected to 1.9 Å resolution. This is the first enzyme with glucoronoyl esterase activity to be crystallized; its structure will be valuable in lignocellulose-degradation research

  1. Crystallization and preliminary X-ray diffraction analysis of the glucuronoyl esterase catalytic domain from Hypocrea jecorina

    Energy Technology Data Exchange (ETDEWEB)

    Wood, S. J. [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Li, X.-L.; Cotta, M. A. [Fermentation Biotechnology Research Unit, National Center for Agricultural Utilization Research, USDA-ARS, Peoria, Illinois 61604 (United States); Biely, P. [Institute of Chemistry, Slovak Academy of Sciences, 845 38 Bratislava (Slovakia); Duke, N. E. C.; Schiffer, M.; Pokkuluri, P. R., E-mail: rajp@anl.gov [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2008-04-01

    The catalytic domain of the glucuronoyl esterase from H. jecorina was overexpresssed, purified and crystallized in space group P2{sub 1}2{sub 1}2{sub 1}. X-ray diffraction data were collected to 1.9 Å resolution. The catalytic domain of the glucuronoyl esterase from Hypocrea jecorina (anamorph Trichoderma reesei) was overexpresssed, purified and crystallized by the sitting-drop vapor-diffusion method using 1.4 M sodium/potassium phosphate pH 6.9. The crystals belonged to space group P2{sub 1}2{sub 1}2{sub 1} and X-ray diffraction data were collected to 1.9 Å resolution. This is the first enzyme with glucoronoyl esterase activity to be crystallized; its structure will be valuable in lignocellulose-degradation research.

  2. Characterization of a cold-adapted esterase and mutants from a psychotolerant Pseudomonas sp. strain.

    Science.gov (United States)

    Dong, Juan; Gasmalla, Mohammed A A; Zhao, Wei; Sun, Jingtao; Liu, Wenyu; Wang, Mingming; Han, Liang; Yang, Ruijin

    2017-09-01

    A cold-adapted esterase-producing strain named T1-39 was isolated from Glacier No. 1, Tianshan, People's Republic of China and identified as Pseudomonas sp. from 16S rRNA sequence analysis. The esterase (EstT1-39) secreted by this strain preferentially hydrolyzed esters of glycerol with short- and medium-chain fatty acids. Mutants of T1-39 were generated by the atmospheric and room temperature plasma method and screened for enhanced esterase activity. Among all the mutants, strain TB11 had 4.45-fold higher esterase productivity than T1-39, with high genetic stability over 10 generations of continuous cultivation. Maximum activity of EstT1-39 and EstTB11 was observed at 30 ℃, pH 9.0 and 25 ℃, pH 8.5, respectively. EstTB11 was thermally more stable (50 ℃ for 1 H) and active over a broader pH range than EstT1-39. EstTB11 also retained 38% of its maximal activity at 0 ℃ and was found to be able to hydrolyze milk fats into short- and medium-chain fatty acids at 4 ℃. The characteristics of EstT1-39 made it a cold-adapted enzyme and the EstTB11 from the mutant, with its higher activity at lower temperatures, may be suitable for the production of aromas and flavors in the dairy industry. © 2016 International Union of Biochemistry and Molecular Biology, Inc.

  3. Enhancement of capacitance performance of activated carbon—Polyaniline composites by introducing methyl orange

    International Nuclear Information System (INIS)

    Jia Yujie; Jiang Jianchun; Sun Kang; Dai Tingyang

    2012-01-01

    Activated carbon–methyl orange–polyaniline (AC–MO–PAn) composites have been synthesized for the first time. The structural properties of the composites have been characterized with nitrogen absorption–desorption, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The electrostatic force between MO molecules and aniline (An) salt is assumed to promote the adsorption of aniline on the surface of AC. On the other hand, the sulfonic groups in MO molecules play a role of dopant and provide active sites for the polymerization of aniline. Although the loading amount and structure of PAn in as-prepared AC–MO–PAn composites and conventional AC–PAn composites are almost the same, the electrochemical measurements indicate that the AC–MO–PAn composites have preferable capacitive performance and are favorable to be used as the electrode materials in supercapacitors.

  4. {sup 13}C-Methyl isocyanide as an NMR probe for cytochrome P450 active sites

    Energy Technology Data Exchange (ETDEWEB)

    McCullough, Christopher R.; Pullela, Phani Kumar [Marquette University, Chemical Proteomics Facility at Marquette, Department of Chemistry (United States); Im, Sang-Choul; Waskell, Lucy [University of Michigan and VA Medical Center, Department of Anesthesiology (United States); Sem, Daniel S. [Marquette University, Chemical Proteomics Facility at Marquette, Department of Chemistry (United States)], E-mail: Daniel.sem@marquette.edu

    2009-03-15

    The cytochromes P450 (CYPs) play a central role in many biologically important oxidation reactions, including the metabolism of drugs and other xenobiotic compounds. Because they are often assayed as both drug targets and anti-targets, any tools that provide: (a) confirmation of active site binding and (b) structural data, would be of great utility, especially if data could be obtained in reasonably high throughput. To this end, we have developed an analog of the promiscuous heme ligand, cyanide, with a {sup 13}CH{sub 3}-reporter attached. This {sup 13}C-methyl isocyanide ligand binds to bacterial (P450cam) and membrane-bound mammalian (CYP2B4) CYPs. It can be used in a rapid 1D experiment to identify binders, and provides a qualitative measure of structural changes in the active site.

  5. PRODUCTION AND CHARACTERIZATION OF AN ALKALOTHERMOSTABLE, ORGANIC SOLVENT TOLERANT AND SURFACTANT TOLERANT ESTERASE PRODUCED BY A THERMOPHILIC BACTERIUM GEOBACILLUS SP. AGP-04, ISOLATED FROM BAKRESHWAR HOT SPRING, INDIA

    Directory of Open Access Journals (Sweden)

    Amit Ghati

    2013-10-01

    Full Text Available A thermophilic bacteria, Geobacillus sp. AGP-04, isolated from Surya Kund hot spring, Bakreshwar, West Bengal, India was studied in terms of capability of tributyrin hydrolysis and characterization of its thermostable esterase activity using p-nitrophenyl butyrate (PNPB as substrate. The extracellular crude preparation was characterized in terms of pH and temperature optima and stability, organic solvent tolerance capacity and stability, substrate specificity, surfactant tolerance capacity, kinetic parameters and activation/inhibition behavior towards some metal ions and chemicals. Tributyrin agar assay exhibited that Geobacillus sp. AGP-04 secretes an extracellular esterase. The Vmax and Km values of the esterase were found to be 5099 U/Land 103.5µM, respectively in the presence of PNPB as substrate. The optimum temperature and pH, for Geobacillus sp. AGP-04 esterase was 60oC and 8.0, respectively. Although the enzyme activity was not significantly altered by incubating crude extract solution at 20-70oC for 1 hour, the enzyme activity was fully lost at 90oC for same incubation period. The pH stability profile showed that original crude esterase activity is stable at a broad range (pH 5.0-10.0. Moreover, the enzyme was highly organic solvent and surfactant tolerant. The effect of some chemical on crude esterase activity indicated that Geobacillus sp. AGP-04 produce an esterase which contains a serine residue in active site and for its activity -SH groups are essential. Besides, enzyme production was highly induced if fermentation medium contain polysaccharides and oil as carbon source.

  6. Novel Cold-Adapted Esterase MHlip from an Antarctic Soil Metagenome

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    Moreno Galleni

    2013-01-01

    Full Text Available An Antarctic soil metagenomic library was screened for lipolytic enzymes and allowed for the isolation of a new cytosolic esterase from the a/b hydrolase family 6, named MHlip. This enzyme is related to hypothetical genes coding esterases, aryl-esterases and peroxydases, among others. MHlip was produced, purified and its activity was determined. The substrate profile of MHlip reveals a high specificity for short p-nitrophenyl-esters. The apparent optimal activity of MHlip was measured for p-nitrophenyl-acetate, at 33 °C, in the pH range of 6–9. The MHlip thermal unfolding was investigated by spectrophotometric methods, highlighting a transition (Tm at 50 °C. The biochemical characterization of this enzyme showed its adaptation to cold temperatures, even when it did not present evident signatures associated with cold-adapted proteins. Thus, MHlip adaptation to cold probably results from many discrete structural modifications, allowing the protein to remain active at low temperatures. Functional metagenomics is a powerful approach to isolate new enzymes with tailored biophysical properties (e.g., cold adaptation. In addition, beside the ever growing amount of sequenced DNA, the functional characterization of new catalysts derived from environment is still required, especially for poorly characterized protein families like α/b hydrolases.

  7. Discovery of potential cholesterol esterase inhibitors using in silico docking studies

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    Thirumalaisamy Sivashanmugam

    2013-08-01

    Full Text Available New drug discovery is considered broadly in terms of two kinds of investiga-tional activities such as exploration and exploitation. This study deals with the evaluation of the cholesterol esterase inhibitory activity of flavonoids apigenin, biochanin, curcumin, diosmetin, epipervilline, glycitein, okanin, rhamnazin and tangeritin using in silico docking studies. In silico docking studies were carried out using AutoDock 4.2, based on the Lamarckian genetic algorithm principle. The results showed that all the selected flavonoids showed binding energy ranging between -7.08 kcal/mol to -5.64 kcal/mol when compared with that of the standard compound gallic acid (-4.11 kcal/mol. Intermolecular energy (-9.13 kcal/mol to -7.09 kcal/mol and inhibition constant (6.48 µM to 73.18 µM of the ligands also coincide with the binding energy. All the selected flavonoids contributed cholesterol esterase inhibitory activity, these molecular docking analyses could lead to the further develop-ment of potent cholesterol esterase inhibitors for the treatment of obesity.

  8. Essential Oil Composition and Antimicrobial Activity of Methyl cinnamate-Linalool Chemovariant of Ocimum basilicum L. from India

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    Rajendra Chandra Padalia

    2017-03-01

    Full Text Available The essential oils obtained from hydrodistillation of Ocimum basilicum L. harvested at four different growth stages during spring-summer and rain-autumn cropping seasons , were characterized using GC and GC-MS. The e ssential oil yield was found to vary from 0.28–0.32% and 0.40–0.52% during spring-summer and rain-autumn cropping season, respectively with its maximal at full bloom stage. Altogether , forty constituents, comprising 94.9–98.3% were identified represented by ( E -methyl cinnamate (36.6 – 66.4%, linalool (11.2 – 43.8%, and (Z -methyl cinnamate (5.4-7.6% as main constituents. Results showed that growth stages strongly influenced the chemical composition of the essential oil in two cropping seasons, particularly concerning to the content of ( E -methyl cinnamate and linalool. Seed setting stage was optimized for harvesting ( E -methyl cinnamate rich oil (66.4% in rain-winter cropping season. The antimicrobial potential of the essential oil was tested againist eight pathogenic bacteria and three fungal strains. Antimicrobial assay showed that the essential oil possessed good antibacterial activity against Streptococcus mutans, Staphylococcus epidermidis, Escherichia coli , and antifungal activity against Candida kefyr and Candida albicans. Ocimum basilicum , essential oil, ( E - methyl cinnamate, linalool, antibacterial activity, antifungal activity

  9. Interactions between resin monomers and commercial composite resins with human saliva derived esterases.

    Science.gov (United States)

    Jaffer, F; Finer, Y; Santerre, J P

    2002-04-01

    Cholesterol esterase (CE) and pseudocholinesterase (PCE) have been reported to degrade commercial and model composite resins containing bisphenylglycidyl dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) or the latter in combination with urethane modified BisGMA monomer systems. In addition, human saliva has been shown to contain esterase like activities similar to CE and PCE. Hence, it was the aim of the current study to determine to what extent human saliva could degrade two common commercial composite resins (Z250 from 3M Inc. and Spectrum TPH from L.D. Caulk) which contain the above monomer systems. Saliva samples from different volunteers were collected, processed, pooled, and freeze-dried. TEGDMA and BisGMA monomers were incubated with human saliva derived esterase activity (HSDEA) and their respective hydrolysis was monitored using high performance liquid chromatography (HPLC). Both monomers were completely hydrolyzed within 25 h by HSDEA. Photopolymerized composites were incubated with buffer or human saliva (pH 7.0 and 37 C) for 2, 8 and 16 days. The incubation solutions were analyzed using HPLC and mass spectrometry. Surface morphology characterization was carried out using scanning electron microscopy. Upon biodegradation, the Z250 composite yielded higher amounts of BisGMA and TEGDMA related products relative to the TPH composite. However, there were higher amounts of ethoxylated bis-phenol A released from the TPH material. In terms of total mass of products released, human saliva demonstrated a greater ability to degrade Z250. In summary, HSDEA has been shown to contain esterase activities that can readily catalyze the biodegradation of current commercial composite resins.

  10. Seedless synthesis and efficient recyclable catalytic activity of Ag@Fe nanocomposites towards methyl orange

    Science.gov (United States)

    Alzahrani, Salma Ahmed; Malik, Maqsood Ahmad; Al-Thabaiti, Shaeel Ahmed; Khan, Zaheer

    2018-03-01

    This work demonstrates a competitive reduction method of synthesis of nanomaterials. In this method along cetyltrimethylammonium bromide (CTAB), the reduction of Ag+ and Fe3+ ions is achieved by ascorbic acid-to-bimetallic Ag@Fe yellow-colored nanomaterials. The shape of UV-visible spectra and wavelengths absorbed of Ag@Fe can be tuned from ca. 290-600 nm by controlling [CTAB] and [Ag+]. The apparent first-order rate constants were calculated within the approximation of 6.1 × 10-3 s-1. The as-prepared Ag@Fe NPs have been found to be very important catalyst in terms of depredate methyl orange in vicinity of sodium borohydride (NaBH4), which exhibits excellent efficiency and re-usability in the prototypical reaction. The cmc of cationic surfactant CTAB has been determined by conductivity method under different experimental conditions. In the presence of CTAB, Ag+ and Fe3+ ions reduce to Ag@Fe core/shell nanoparticles, comprehend a change in wavelength and intensity of SRP band. The apparent first-order rate constant, activation energy, and turnover frequency for the methyl orange reduction catalyzed by Ag@Fe NPs were found to be 1.6 × 10-3 s-1, 58.2 kJ mol-1, and 1.1 × 10-3 s-1, respectively.

  11. Induction of mitophagy-mediated antitumor activity with folate-appended methyl-β-cyclodextrin

    Directory of Open Access Journals (Sweden)

    Kameyama K

    2017-04-01

    Full Text Available Kazuhisa Kameyama,1,* Keiichi Motoyama,1,* Nao Tanaka,1 Yuki Yamashita,1 Taishi Higashi,1 Hidetoshi Arima1,2,* 1Department of Physical Pharmaceutics, Graduate School of Pharmaceutical Sciences, 2Program for Leading Graduate Schools “HIGO (Health Life Science: Interdisciplinary and Glocal Oriented Program,” Kumamoto University, Kumamoto, Japan *These authors contributed equally to this work Abstract: Mitophagy is the specific autophagic elimination system of mitochondria, which regulates cellular survival via the removal of damaged mitochondria. Recently, we revealed that folate-appended methyl-β-cyclodextrin (FA-M-β-CyD provides selective antitumor activity in folate receptor-α (FR-α-expressing cells by the induction of autophagy. In this study, to gain insight into the detailed mechanism of this antitumor activity, we focused on the induction of mitophagy by the treatment of FR-α-expressing tumor cells with FA-M-β-CyD. In contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered KB cells, human epithelial cells from a fatal cervical carcinoma (FR-α (+ through FR-α-mediated endocytosis. The transmembrane potential of isolated mitochondria after treatment with FA-M-β-CyD was significantly elevated. In addition, FA-M-β-CyD lowered adenosine triphosphate (ATP production and promoted reactive oxygen species production in KB cells (FR-α (+. Importantly, FA-M-β-CyD enhanced light chain 3 (LC3 conversion (LC3-I to LC3-II in KB cells (FR-α (+ and induced PTEN-induced putative kinase 1 (PINK1 protein expression, which is involved in the induction of mitophagy. Furthermore, FA-M-β-CyD had potent antitumor activity in BALB/c nu/nu mice xenografted with KB cells (FR-α (+ without any significant side effects. Taken together, these findings demonstrate that the autophagic cell death elicited by FA-M-β-CyD could be associated with mitophagy induced by an impaired mitochondrial function. Keywords: mitophagy, autophagy, folate receptor, methyl

  12. Core shell methyl methacrylate chitosan nanoparticles: In vitro mucoadhesion and complement activation

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    F Atyabi

    2011-10-01

    Full Text Available Background and the purpose of the study: Studies show that chitosan nanoparticles increase mucoadhesivity and penetration of large molecules across mucosal surface. The aim of the present study was to investigate the use of thiolated chitosan in the development of polysaccharide-coated nanoparticles in order to confer specific functionality to the system. Methods: Methyl methacrylate nanoparticles were coated with thiolated chitosan using a radical polymerization method. Thiolation was carried out using glutathione (GSH to improve mucoadhesivity and permeation enhancing properties of chitosan. Mucoadhesion studies were carried out by calculating the amount of mucin adsorbed on nanoparticles in a specific period of time. Complement consumption was assessed in human serum (HS by measurement of the hemolytic capacity of the complement system after contact with nanoparticles.   Results:   The FT-IR and 1HNMR spectra both confirmed the synthesis and showed the conjugation of thiolated chitosan to methyl methacrylate (MMA homopolymer. Nanoparticles were spherical having a mean diameter within the range of about 334-650 nm and their positive zeta potential values indicated the presence of the cationic polysaccharide at the nanoparticle surface. Increasing the amount of thiolated chitosan led to mucoadhesivity and complement activation. However there was not dose dependent correlation between these phenomenons and the absence of thiolated chitosan led to particles with larger size, and without ability to activate complement process. Major conclusion: It can be concluded that nanoparticles could be used for the mucosal delivery of peptides and proteins. Results show that the thiolated chitosan had higher mucoadhesion and complement activation than unmodified chitosan.

  13. Induction of mitophagy-mediated antitumor activity with folate-appended methyl-β-cyclodextrin.

    Science.gov (United States)

    Kameyama, Kazuhisa; Motoyama, Keiichi; Tanaka, Nao; Yamashita, Yuki; Higashi, Taishi; Arima, Hidetoshi

    2017-01-01

    Mitophagy is the specific autophagic elimination system of mitochondria, which regulates cellular survival via the removal of damaged mitochondria. Recently, we revealed that folate-appended methyl-β-cyclodextrin (FA-M-β-CyD) provides selective antitumor activity in folate receptor-α (FR-α)-expressing cells by the induction of autophagy. In this study, to gain insight into the detailed mechanism of this antitumor activity, we focused on the induction of mitophagy by the treatment of FR-α-expressing tumor cells with FA-M-β-CyD. In contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered KB cells, human epithelial cells from a fatal cervical carcinoma (FR-α (+)) through FR-α-mediated endocytosis. The transmembrane potential of isolated mitochondria after treatment with FA-M-β-CyD was significantly elevated. In addition, FA-M-β-CyD lowered adenosine triphosphate (ATP) production and promoted reactive oxygen species production in KB cells (FR-α (+)). Importantly, FA-M-β-CyD enhanced light chain 3 (LC3) conversion (LC3-I to LC3-II) in KB cells (FR-α (+)) and induced PTEN-induced putative kinase 1 (PINK1) protein expression, which is involved in the induction of mitophagy. Furthermore, FA-M-β-CyD had potent antitumor activity in BALB/c nu/nu mice xenografted with KB cells (FR-α (+)) without any significant side effects. Taken together, these findings demonstrate that the autophagic cell death elicited by FA-M-β-CyD could be associated with mitophagy induced by an impaired mitochondrial function.

  14. Generalized query-based active learning to identify differentially methylated regions in DNA.

    Science.gov (United States)

    Haque, Md Muksitul; Holder, Lawrence B; Skinner, Michael K; Cook, Diane J

    2013-01-01

    Active learning is a supervised learning technique that reduces the number of examples required for building a successful classifier, because it can choose the data it learns from. This technique holds promise for many biological domains in which classified examples are expensive and time-consuming to obtain. Most traditional active learning methods ask very specific queries to the Oracle (e.g., a human expert) to label an unlabeled example. The example may consist of numerous features, many of which are irrelevant. Removing such features will create a shorter query with only relevant features, and it will be easier for the Oracle to answer. We propose a generalized query-based active learning (GQAL) approach that constructs generalized queries based on multiple instances. By constructing appropriately generalized queries, we can achieve higher accuracy compared to traditional active learning methods. We apply our active learning method to find differentially DNA methylated regions (DMRs). DMRs are DNA locations in the genome that are known to be involved in tissue differentiation, epigenetic regulation, and disease. We also apply our method on 13 other data sets and show that our method is better than another popular active learning technique.

  15. Synthesis, and anticonvulsant activity of new amides derived from 3-methyl- or 3-ethyl-3-methyl-2,5-dioxo-pyrrolidin-1-yl-acetic acids.

    Science.gov (United States)

    Obniska, Jolanta; Rapacz, Anna; Rybka, Sabina; Góra, Małgorzata; Kamiński, Krzysztof; Sałat, Kinga; Żmudzki, Paweł

    2016-04-15

    This paper describes the synthesis of the library of 22 new 3-methyl- and 3-ethyl-3-methyl-2,5-dioxo-pyrrolidin-1-yl-acetamides as potential anticonvulsant agents. The maximal electroshock (MES) and the subcutaneous pentylenetetrazole (scPTZ) seizure models were used for screening all the compounds. The 6 Hz model of pharmacoresistant limbic seizures was applied for studying selected derivatives. Six amides were chosen for pharmacological characterization of their antinociceptive activity in the formalin model of tonic pain as well as local anesthetic activity was assessed in mice. The pharmacological data indicate on the broad spectra of activity across the preclinical seizure models. Compounds 10 (ED50=32.08 mg/kg, MES test) and 9 (ED50=40.34 mg/kg, scPTZ test) demonstrated the highest potency. These compounds displayed considerably better safety profiles than clinically relevant antiepileptic drugs phenytoin, ethosuximide, or valproic acid. Several molecules showed antinociceptive and local anesthetic properties. The in vitro radioligand binding studies demonstrated that the influence on the sodium and calcium channels may be one of the essential mechanisms of action. Copyright © 2016. Published by Elsevier Ltd.

  16. Cloning, expression and characterization of a novel esterase from a South China Sea sediment metagenome

    Science.gov (United States)

    Zhang, Hao; Li, Fuchao; Chen, Huaxin; Zhao, Jin; Yan, Jinfei; Jiang, Peng; Li, Ronggui; Zhu, Baoli

    2015-07-01

    Lipolytic enzymes, including esterases and lipases, represent a group of hydrolases that catalyze the cleavage and formation of ester bonds. A novel esterase gene, scsEst01, was cloned from a South China Sea sediment metagenome. The scsEst01 gene consisted of 921 bp encoding 307 amino acid residues. The predicted amino acid sequence shared less than 90% identity with other lipolytic enzymes in the NCBI nonredundant protein database. ScsEst01 was successfully co-expressed in Escherichia coli BL21 (DE3) with chaperones (dnaK-dnaJ-grpE) to prevent the formation of inclusion bodies. The recombinant protein was purified on an immobilized metal ion affinity column containing chelating Sepharose charged with Ni2+. The enzyme was characterized using p -nitrophenol butyrate as a substrate. ScsEst01 had the highest lipolytic activity at 35°C and pH 8.0, indicative of a meso-thermophilic alkaline esterase. ScsEst01 was thermostable at 20°C. The lipolytic activity of scsEst01 was strongly increased by Fe2+, Mn2+ and 1% Tween 80 or Tween 20.

  17. Spatial control of protein phosphatase 2A (de)methylation

    International Nuclear Information System (INIS)

    Longin, Sari; Zwaenepoel, Karen; Martens, Ellen; Louis, Justin V.; Rondelez, Evelien; Goris, Jozef; Janssens, Veerle

    2008-01-01

    Reversible methylation of the protein phosphatase 2A catalytic subunit (PP2A C ) is an important regulatory mechanism playing a crucial role in the selective recruitment of regulatory B subunits. Here, we investigated the subcellular localization of leucine carboxyl methyltransferase (LCMT1) and protein phosphatase methylesterase (PME-1), the two enzymes catalyzing this process. The results show that PME-1 is predominantly localized in the nucleus and harbors a functional nuclear localization signal, whereas LCMT1 is underrepresented in the nucleus and mainly localizes to the cytoplasm, Golgi region and late endosomes. Indirect immunofluorescence with methylation-sensitive anti-PP2A C antibodies revealed a good correlation with the methylation status of PP2A C , demethylated PP2A C being substantially nuclear. Throughout mitosis, demethylated PP2A C is associated with the mitotic spindle and during cytokinesis with the cleavage furrow. Overexpression of PME-1, but not of an inactive mutant, results in increased demethylation of PP2A C in the nucleus, whereas overexpression of a cytoplasmic PME-1 mutant lacking the NLS results in increased demethylation in the cytoplasm-in all cases, however, without any obvious functional consequences. PME-1 associates with an inactive PP2A population, regardless of its esterase activity or localization. We propose that stabilization of this inactive, nuclear PP2A pool is a major in vivo function of PME-1

  18. Biochemical Characterization of a Family 15 Carbohydrate Esterase from a Bacterial Marine Arctic Metagenome.

    Directory of Open Access Journals (Sweden)

    Concetta De Santi

    Full Text Available The glucuronoyl esterase enzymes of wood-degrading fungi (Carbohydrate Esterase family 15; CE15 form part of the hemicellulolytic and cellulolytic enzyme systems that break down plant biomass, and have possible applications in biotechnology. Homologous enzymes are predicted in the genomes of several bacteria, however these have been much less studied than their fungal counterparts. Here we describe the recombinant production and biochemical characterization of a bacterial CE15 enzyme denoted MZ0003, which was identified by in silico screening of a prokaryotic metagenome library derived from marine Arctic sediment. MZ0003 has high similarity to several uncharacterized gene products of polysaccharide-degrading bacterial species, and phylogenetic analysis indicates a deep evolutionary split between these CE15s and fungal homologs.MZ0003 appears to differ from previously-studied CE15s in some aspects. Some glucuronoyl esterase activity could be measured by qualitative thin-layer chromatography which confirms its assignment as a CE15, however MZ0003 can also hydrolyze a range of other esters, including p-nitrophenyl acetate, which is not acted upon by some fungal homologs. The structure of MZ0003 also appears to differ as it is predicted to have several large loop regions that are absent in previously studied CE15s, and a combination of homology-based modelling and site-directed mutagenesis indicate its catalytic residues deviate from the conserved Ser-His-Glu triad of many fungal CE15s. Taken together, these results indicate that potentially unexplored diversity exists among bacterial CE15s, and this may be accessed by investigation of the microbial metagenome. The combination of low activity on typical glucuronoyl esterase substrates, and the lack of glucuronic acid esters in the marine environment suggest that the physiological substrate of MZ0003 and its homologs is likely to be different from that of related fungal enzymes.

  19. Synthesis, Characterization, and Anti-Inflammatory Activities of Methyl Salicylate Derivatives Bearing Piperazine Moiety.

    Science.gov (United States)

    Li, Jingfen; Yin, Yong; Wang, Lisheng; Liang, Pengyun; Li, Menghua; Liu, Xu; Wu, Lichuan; Yang, Hua

    2016-11-23

    In this study, a new series of 16 methyl salicylate derivatives bearing a piperazine moiety were synthesized and characterized. The in vivo anti-inflammatory activities of target compounds were investigated against xylol-induced ear edema and carrageenan-induced paw edema in mice. The results showed that all synthesized compounds exhibited potent anti-inflammatory activities. Especially, the anti-inflammatory activities of compounds M15 and M16 were higher than that of aspirin and even equal to that of indomethacin at the same dose. In addition, the in vitro cytotoxicity activities and anti-inflammatory activities of four target compounds were performed in RAW264.7 macrophages, and compound M16 was found to significantly inhibit the release of lipopolysaccharide (LPS)-induced interleukin (IL)-6 and tumor necrosis factor (TNF)-α in a dose-dependent manner. In addition, compound M16 was found to attenuate LPS induced cyclooxygenase (COX)-2 up-regulation. The current preliminary study may provide information for the development of new and safe anti-inflammatory agents.

  20. Effect of methyl parathion on the muscle and brain acetylcholinesterase activity of matrinxã (Brycon cephalus

    Directory of Open Access Journals (Sweden)

    Almeida Luciana Cristina de

    2005-01-01

    Full Text Available Farming of the freshwater fish is emerging in Brazil and many species from the wild are promising. The teleost matrinxã (Brycon cephalus holds several characteristics such as fast growth rate, high commercial value and adaptability to artificial raring conditions, which make it a promising species for commerce. The use of pesticides in aquatic environment is frequent in Brazil, and methyl parathion is very common in aquaculture. We have determined the enzymatic activity of acetyl cholinesterase in white muscle and brain of matrinxã exposed to 2ppm of environmental methyl parathion for 24 hours. There was 64% and 69% of acetyl cholinesterase inhibition in muscle and brain respectively. These activities were not recovered after 8 days from exposure to this pesticide. It can be concluded that acetyl cholinesterase from those tissues was inhibited by small amounts of methyl parathion, and the main effect was observed in the brain.

  1. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm.

    Science.gov (United States)

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J; Madrid, Susan M; Brinch-Pedersen, Henrik; Holm, Preben B; Scheller, Henrik V

    2010-04-01

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and threefold relative to wild type. The grains were shrivelled and had a 25%-33% decrease in mass. Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13% and 34%. In all the plants, the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  2. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    Energy Technology Data Exchange (ETDEWEB)

    Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben B.; Scheller, Henrik V.

    2009-12-08

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and three fold relative to wild type. The grains were shriveled and had a 25-33% decrease in mass. Extensive analysis of the cell walls showed a 10-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water extractable arabinoxylan, and a shift in the MW of the water extractable arabinoxylan from being mainly larger than 85 kD to being between 2 kD and 85 kD. Ferulic acid esterase expressing grains were also shriveled and the seed weight was decreased by 20-50%. No ferulic acid esterase activity could be detected in wild type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15-40% increase in water unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13 and 34%. In all the plants the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

  3. Toxicity, antimicrobial and antioxidant activities of methyl salicylate dominated essential oils of Laportea aestuans (Gaud

    Directory of Open Access Journals (Sweden)

    Ganiyat K. Oloyede

    2016-09-01

    Full Text Available The colourless essential oils obtained by hydro-distillation from the whole plant of Laportea aestuans (Gaud were analysed by GC and GC/MS. The major constituents in the oil were methyl salicylate (54.50%, fenchol (10.59%, 1, 2-cyclohexanedione dioxime (9.40%, 1, 4-octadiene (8.86% and linalool (3.26%. The toxicity results obtained from brine shrimp lethality test gave LC50 value of 367.1805 μg/ml indicating that the oil is toxic. The oils showed appreciable antimicrobial activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Candida albicans, Rhizopus stolon, Aspergillus niger and Penicillium nonatum at 200 mg/ml when compared to standards; gentamicin for bacteria and tioconazole for fungi. The oil was however very active against the fungi R. stolon and A. niger at 25–200 mg/ml. While the in vitro antioxidant activities of the oils determined by scavenging effect on 2, 2-diphenyl-1-picryl hydrazyl radical method showed that the oils have promising antioxidant activity as a free radical scavenger. At 0.1 and 0.2 mg/ml, the % inhibition of the essential oil (84.46% and 86.87%, respectively was discovered to be higher than the % inhibition of α-tocopherol (15.4% and 12.4%.

  4. Ferulic acid: an antioxidant found naturally in plant cell walls and feruloyl esterases involved in its release and their applications.

    Science.gov (United States)

    Mathew, Sindhu; Abraham, T Emilia

    2004-01-01

    Ferulic acid is the most abundant hydroxycinnamic acid in the plant world and maize bran with 3.1% (w/w) ferulic acid is one of the most promising sources of this antioxidant. The dehydrodimers of ferulic acid are important structural components in the plant cell wall and serve to enhance its rigidity and strength. Feruloyl esterases are a subclass of the carboxylic acid esterases that hydrolyze the ester bond between hydroxycinnamic acids and sugars present in plant cell walls and they have been isolated from a wide range of microorganisms, when grown on complex substrates such as cereal brans, sugar beet pulp, pectin and xylan. These enzymes perform a function similar to alkali in the deesterification of plant cell wall and differ in their specificities towards the methyl esters of cinnamic acids and ferulolylated oligosaccharides. They act synergistically with xylanases and pectinases and facilitate the access of hydrolases to the backbone of cell wall polymers. The applications of ferulic acid and feruloyl esterase enzymes are many and varied. Ferulic acid obtained from agricultural byproducts is a potential precursor for the production of natural vanillin, due to the lower production cost.

  5. Eco-friendly surface modification on polyester fabrics by esterase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping, E-mail: jipingwanghz@gmail.com

    2014-03-01

    Graphical abstract: - Highlights: • We used a simple and easy way to measure the enzyme activity. • We studied the mechanism by characterizing the chemical changes in the surface of fabric. • We studied the advantages in surface wettability, fiber integrity and mechanical performance of cutinase treated fabrics. • Cutinase pretreated fibers exhibited much improved fabric wicking and better fiber integrity comparing to alkali treated ones. • Cutinase pretreatment technology promotes energy conservation and emission reduction. - Abstract: Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

  6. Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

    DEFF Research Database (Denmark)

    Harholt, Jesper; Bach, Inga Christensen; Lind Bouquin, Solveig

    2010-01-01

    Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used....... Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase......-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan...

  7. SYNTHESIS OF METHYL TERT-BUTYL ETHER CATALYZED BY ACIDIC ION-EXCHANGE RESINS - INFLUENCE OF THE PROTON ACTIVITY

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1995-01-01

    The catalytic activity of various strong acid ion-exchange resins on the synthesis of methyl tert-butyl ether (MtBE) from methanol and isobutene has been investigated. Relative to Amberlyst 15, Kastel CS 381 and Amberlyst CSP have similar rate constants, whereas Duolite ES 276 and Amberlyst XE 307

  8. Body size, physical activity and risk of colorectal cancer with or without the CpG island methylator phenotype (CIMP)

    NARCIS (Netherlands)

    Hughes, L.A.E.; Simons, C.C.J.M.; Brandt, P.A. van den; Goldbohm, R.A.; Goeij, A.F. de; Bruïne, A.P. de; Engeland, M. van; Weijenberg, M.P.

    2011-01-01

    Background: We investigated how body size and physical activity influence the risk of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC). Methods: In the Netherlands Cohort Study (n = 120,852), risk factors were self-reported at baseline in 1986. After 7.3 years of follow-up, 603

  9. Methyl jasmonate enhances memory performance through inhibition of oxidative stress and acetylcholinesterase activity in mice.

    Science.gov (United States)

    Eduviere, Anthony T; Umukoro, S; Aderibigbe, Adegbuyi O; Ajayi, Abayomi M; Adewole, Folashade A

    2015-07-01

    Current research effort focuses on the development of safer natural compounds with multipronged mechanisms of action that could be used to ameliorate memory deficits in patients with Alzheimer's disease, as cure for the disease still remains elusive. In this study, we evaluated the effect of methyl jasmonate (MJ), a naturally occurring bioactive compound on memory, acetylcholinesterase activity and biomarkers of oxidative stress in mice. Male Swiss mice were treated with intraperitoneal injection of MJ (10-40 mg/kg) alone or in combination with scopolamine (3mg/kg) once daily for 7 days. Thirty minutes after the last treatment, memory functions were assessed using Y-maze and object recognition tests. Thereafter, acetylcholinesterase activity and levels of biomarkers of oxidative stress were assessed in mice brains using standard biochemical procedures. MJ significantly enhanced memory performance and reversed scopolamine-induced cognitive impairment in mice. MJ demonstrated significant inhibition of acetylcholinesterase activity suggesting increased cholinergic neurotransmission. It further decreased malondialdehyde concentrations in mouse brain indicating antioxidant activity. Moreover, MJ significantly increased glutathione levels and activity of antioxidant enzymes (catalase and superoxide dismutase) in mice brains. The increased oxidative stress; evidenced by elevated levels of malondialdehyde and decreased antioxidant defense systems in scopolamine-treated mice was attenuated by MJ. The results of this study suggest that MJ may be useful in conditions associated with memory dysfunctions or age-related cognitive decline. The positive effect of MJ on memory may be related to inhibition of oxidative stress and enhancement of cholinergic neurotransmission through inhibition of acetylcholinesterase activity. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic Acid Amides.

    Science.gov (United States)

    Du, Shijie; Tian, Zaimin; Yang, Dongyan; Li, Xiuyun; Li, Hong; Jia, Changqing; Che, Chuanliang; Wang, Mian; Qin, Zhaohai

    2015-05-08

    A series of novel 3-(difluoromethyl)-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-yl)phenyl)-3-(difluoro-methyl)-1-methyl-1H-pyrazole-4-carboxamide (9m) exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  11. Synthesis, Antifungal Activity and Structure-Activity Relationships of Novel 3-(Difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic Acid Amides

    Directory of Open Access Journals (Sweden)

    Shijie Du

    2015-05-01

    Full Text Available A series of novel 3-(difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid amides were synthesized and their activities were tested against seven phytopathogenic fungi by an in vitro mycelia growth inhibition assay. Most of them displayed moderate to excellent activities. Among them N-(2-(5-bromo-1H-indazol-1-ylphenyl-3-(difluoro-methyl-1-methyl-1H-pyrazole-4-carboxamide (9m exhibited higher antifungal activity against the seven phytopathogenic fungi than boscalid. Topomer CoMFA was employed to develop a three-dimensional quantitative structure-activity relationship model for the compounds. In molecular docking, the carbonyl oxygen atom of 9m could form hydrogen bonds towards the hydroxyl of TYR58 and TRP173 on SDH.

  12. Exogenous Methyl Jasmonate Treatment Increases Glucosinolate Biosynthesis and Quinone Reductase Activity in Kale Leaf Tissue

    Science.gov (United States)

    Ku, Kang-Mo; Jeffery, Elizabeth H.; Juvik, John A.

    2014-01-01

    Methyl jasmonate (MeJA) spray treatments were applied to the kale varieties ‘Dwarf Blue Curled Vates’ and ‘Red Winter’ in replicated field plantings in 2010 and 2011 to investigate alteration of glucosinolate (GS) composition in harvested leaf tissue. Aqueous solutions of 250 µM MeJA were sprayed to saturation on aerial plant tissues four days prior to harvest at commercial maturity. The MeJA treatment significantly increased gluconasturtiin (56%), glucobrassicin (98%), and neoglucobrassicin (150%) concentrations in the apical leaf tissue of these genotypes over two seasons. Induction of quinone reductase (QR) activity, a biomarker for anti-carcinogenesis, was significantly increased by the extracts from the leaf tissue of these two cultivars. Extracts of apical leaf tissues had greater MeJA mediated increases in phenolics, glucosinolate concentrations, GS hydrolysis products, and QR activity than extracts from basal leaf tissue samples. The concentration of the hydrolysis product of glucoraphanin, sulforphane was significantly increased in apical leaf tissue of the cultivar ‘Red Winter’ in both 2010 and 2011. There was interaction between exogenous MeJA treatment and environmental conditions to induce endogenous JA. Correlation analysis revealed that indole-3-carbanol (I3C) generated from the hydrolysis of glucobrassicin significantly correlated with QR activity (r = 0.800, Pkale leaf tissues of both cultivars in 2011. Correlation analysis of these results indicated that sulforaphane, NI3C, neoascorbigen, I3C, and diindolylmethane were all significantly correlated with QR activity. Thus, increased QR activity may be due to combined increases in phenolics (quercetin and kaempferol) and GS hydrolysis product concentrations rather than by individual products alone. PMID:25084454

  13. 4'-Methyl derivatives of 5-MOP and 5-MOA: synthesis, photoreactivity, and photobiological activity.

    Science.gov (United States)

    Gia, O; Anselmo, A; Conconi, M T; Antonello, C; Uriarte, E; Caffieri, S

    1996-10-25

    The synthesis and photobiological activity of four new 4'-methyl derivatives of 5-MOP (5-methoxypsoralen) and 5-MOA (5-methoxyangelicin), i.e., 4,4'-dimethyl-5-methoxypsoralen, 3,4'-dimethyl-5-methoxypsoralen, 4,4'-dimethyl-5-methoxyangelicin, and 3,4'-dimethyl-5-methoxyangelicin, are described. All these compounds photobind efficiently to DNA. The DNA-photobinding process was investigated using various nucleic acid structures such as double-helix DNA, bacterial DNA, and synthetic polydeoxyribonucleotides. Photoreaction experiments showed that, unlike 8-MOP (8-methoxypsoralen) and 5-MOP, both angular derivatives bind thymine and cytosine with the same efficiency. The principal nucleoside-psoralen monoadducts were isolated and characterized after enzymatic digestion or acid hydrolysis. Biological activity studies revealed a good correlation with the extent of covalent photoaddition. Moreover, the two angular derivatives and the 4,4'-dimethyl-5-methoxypsoralen were unable to induce skin erythema, in striking contrast with the reference drugs, 8-MOP and 5-MOP; only the 3,4'-dimethyl-5-methoxypsoralen caused erythema, although to a substantially lower extent than that induced by the two parent compounds.

  14. Anti-inflammatory activity of methyl palmitate and ethyl palmitate in different experimental rat models

    Energy Technology Data Exchange (ETDEWEB)

    Saeed, Noha M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); El-Demerdash, Ebtehal [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt); Abdel-Rahman, Hanaa M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); Algandaby, Mardi M. [Department of Biology (Botany), Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Al-Abbasi, Fahad A. [Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-Naim, Ashraf B., E-mail: abnaim@pharma.asu.edu.eg [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)

    2012-10-01

    Methyl palmitate (MP) and ethyl palmitate (EP) are naturally occurring fatty acid esters reported as inflammatory cell inhibitors. In the current study, the potential anti-inflammatory activity of MP and EP was evaluated in different experimental rat models. Results showed that MP and EP caused reduction of carrageenan-induced rat paw edema in addition to diminishing prostaglandin E2 (PGE2) level in the inflammatory exudates. In lipopolysaccharide (LPS)-induced endotoxemia in rats, MP and EP reduced plasma levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). MP and EP decreased NF-κB expression in liver and lung tissues and ameliorated histopathological changes caused by LPS. Topical application of MP and EP reduced ear edema induced by croton oil in rats. In the same animal model, MP and EP reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In conclusion, this study demonstrates the effectiveness of MP and EP in combating inflammation in several experimental models. -- Highlights: ► Efficacy of MP and EP in combating inflammation was displayed in several models. ► MP and EP reduced carrageenan-induced rat paw edema and prostaglandin E2 level. ► MP and EP decreased TNF-α and IL-6 levels in experimental endotoxemia. ► MP and EP reduced NF-κB expression and histological changes in rat liver and lung. ► MP and EP reduced croton oil-induced ear edema and neutrophil infiltration.

  15. TWO-PARAMETER ISOTHERMS OF METHYL ORANGE SORPTION BY PINECONE DERIVED ACTIVATED CARBON

    Directory of Open Access Journals (Sweden)

    M. R. Samarghandi ، M. Hadi ، S. Moayedi ، F. Barjasteh Askari

    2009-10-01

    Full Text Available The adsorption of a mono azo dye methyl-orange (MeO onto granular pinecone derived activated carbon (GPAC, from aqueous solutions, was studied in a batch system. Seven two-parameter isotherm models Langmuir, Freundlich, Dubinin-Radushkevic, Temkin, Halsey, Jovanovic and Hurkins-Jura were used to fit the experimental data. The results revealed that the adsorption isotherm models fitted the data in the order of Jovanovic (X2=1.374 > Langmuir > Dubinin-Radushkevic > Temkin > Freundlich > Halsey > Hurkins-Jura isotherms. Adsorption isotherms modeling showed that the interaction of dye with activated carbon surface is localized monolayer adsorption. A comparison of kinetic models was evaluated for the pseudo-second order, Elovich and Lagergren kinetic models. Lagergren first order model was found to agree well with the experimental data (X2=9.231. In order to determine the best-fit isotherm and kinetic models, two error analysis methods of Residual Mean Square Error and Chi-square statistic (X2 were used to evaluate the data.

  16. Biochemical Characterization and Relative Expression Levels of Multiple Carbohydrate Esterases of the Xylanolytic Rumen Bacterium Prevotella ruminicola 23 Grown on an Ester-Enriched Substrate ▿ †

    Science.gov (United States)

    Kabel, Mirjam A.; Yeoman, Carl J.; Han, Yejun; Dodd, Dylan; Abbas, Charles A.; de Bont, Jan A. M.; Morrison, Mark; Cann, Isaac K. O.; Mackie, Roderick I.

    2011-01-01

    We measured expression and used biochemical characterization of multiple carbohydrate esterases by the xylanolytic rumen bacterium Prevotella ruminicola 23 grown on an ester-enriched substrate to gain insight into the carbohydrate esterase activities of this hemicellulolytic rumen bacterium. The P. ruminicola 23 genome contains 16 genes predicted to encode carbohydrate esterase activity, and based on microarray data, four of these were upregulated >2-fold at the transcriptional level during growth on an ester-enriched oligosaccharide (XOSFA,Ac) from corn relative to a nonesterified fraction of corn oligosaccharides (AXOS). Four of the 16 esterases (Xyn10D-Fae1A, Axe1-6A, AxeA1, and Axe7A), including the two most highly induced esterases (Xyn10D-Fae1A and Axe1-6A), were heterologously expressed in Escherichia coli, purified, and biochemically characterized. All four enzymes showed the highest activity at physiologically relevant pH (6 to 7) and temperature (30 to 40°C) ranges. The P. ruminicola 23 Xyn10D-Fae1A (a carbohydrate esterase [CE] family 1 enzyme) released ferulic acid from methylferulate, wheat bran, corn fiber, and XOSFA,Ac, a corn fiber-derived substrate enriched in O-acetyl and ferulic acid esters, but exhibited negligible activity on sugar acetates. As expected, the P. ruminicola Axe1-6A enzyme, which was predicted to possess two distinct esterase family domains (CE1 and CE6), released ferulic acid from the same substrates as Xyn10D-Fae1 and was also able to cleave O-acetyl ester bonds from various acetylated oligosaccharides (AcXOS). The P. ruminicola 23 AxeA1, which is not assigned to a CE family, and Axe7A (CE7) were found to be acetyl esterases that had activity toward a broad range of mostly nonpolymeric acetylated substrates along with AcXOS. All enzymes were inhibited by the proximal location of other side groups like 4-O-methylglucuronic acid, ferulic acid, or acetyl groups. The unique diversity of carbohydrate esterases in P. ruminicola 23

  17. Magnetic Fe2MO4 (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    International Nuclear Information System (INIS)

    Nguyen, Thi Dung; Phan, Ngoc Hoa; Do, Manh Huy; Ngo, Kim Tham

    2011-01-01

    We present a simple and efficient method for the fabrication of magnetic Fe 2 MO 4 (M:Fe and Mn) activated carbons (Fe 2 MO 4 /AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe 2 MnO 4 /AC-H showed higher catalytic activity in the methyl orange oxidation than Fe 3 O 4 /AC-H. The effect of operational parameters (pH, catalyst loading H 2 O 2 dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  18. Homogalacturonan methyl-esterification and plant development.

    Science.gov (United States)

    Wolf, Sebastian; Mouille, Grégory; Pelloux, Jérome

    2009-09-01

    The ability of a plant cell to expand is largely defined by the physical constraints imposed by its cell wall. Accordingly, cell wall properties have to be regulated during development. The pectic polysaccharide homogalacturonan is a major component of the plant primary walls. Biosynthesis and in muro modification of homogalacturonan have recently emerged as key determinants of plant development, controlling cell adhesion, organ development, and phyllotactic patterning. This review will focus on recent findings regarding impact of homogalacturonan content and methyl-esterification status of this polymer on plant life. De-methyl-esterification of homogalacturonan occurs through the action of the ubiquitous enzyme 'pectin methyl-esterase'. We here describe various strategies developed by the plant to finely tune the methyl-esterification status of homogalacturonan along key events of the plant lifecycle.

  19. Fibrillarin methylates H2A in RNA polymerase I trans-active promoters in Brassica oleracea

    Directory of Open Access Journals (Sweden)

    lloyd eLoza-Muller

    2015-11-01

    Full Text Available Fibrillarin is a well conserved methyltransferase involved in several if not all of the more than 100 methylations sites in rRNA which are essential for proper ribosome function. It is mainly localized in the nucleoli and Cajal bodies inside the cell nucleus where it exerts most of its functions. In plants, fibrillarin binds directly the guide RNA together with Nop56, Nop58 and 15.5ka proteins to form a snoRNP complex that selects the sites to be methylated in pre-processing of ribosomal RNA. Recently, the yeast counterpart NOP1 was found to methylate histone H2A in the nucleolar regions. Here we show that plant fibrillarin can also methylate histone H2A. In Brassica floral meristem cells the methylated histone H2A is mainly localized in the nucleolus but unlike yeast or human cells it also localize in the periphery of the nucleus. In specialized transport cells the pattern is altered and it exhibits a more diffuse staining in the nucleus for methylated histone H2A as well as for fibrillarin. Here we also show that plant fibrillarin is capable of interacting with H2A and carry out its methylation in the rDNA promoter.

  20. Activity of Aniline Methylation over Fe-Cu-Cr Ternary Spinel Systems

    Directory of Open Access Journals (Sweden)

    Reni George

    2014-03-01

    Full Text Available A series of spinels having thegeneral formula CuCr2-xFexO4 with x=0.25,0.75, 1.25, 1.75 were prepared by co-precipitation method. The catalysts werecharacterized by various physico-chemical methods like XRD, BET, UV-DRS, SEM,EDX, TPD etc. The reaction of aniline with methanol was studied in a fixed-bedreactor system as a potential source for the production of various methylanilines. It was observed that systems possessing low ‘x’ values are highlyselective and active for N-monoalkylation of aniline leading toN-methylaniline. Reaction parameters were properly varied to optimize thereaction conditions for obtaining N-methylaniline selectively and in betteryield. Among the systems CuCr1.75Fe0.25O4 isremarkable due to its very high activity and excellent stability. Under theoptimized conditions N-methylaniline selectivity exceeded 91%. CuCr1.25Fe0.75O4gives better conversion than CuCr1.75Fe0.25O4in CuCr2-xFexO4 series. The Lewis acid sitesof the catalysts are mainly responsible for the good catalytic performance. © 2014 BCREC UNDIP. All rights reservedSubmitted: 18th July 2013; Revised: 5th November 2013; Accepted: 1st December 2013[How to Cite: George, R., George, K., Sugunan, S. (2014. Activity of Aniline Methylation over Fe-Cu-Cr Ternary Spinel Systems. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 39-44. (doi:10.9767/bcrec.9.1.5169.39-44][Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.5169.39-44] 

  1. Biomimetic synthesis of silver nanoparticles and evaluation of their catalytic activity towards degradation of methyl orange

    Science.gov (United States)

    Manjari Mishra, Pravat; Bihari Pani, Khirod

    2017-11-01

    This paper described the significant effect of process variables like reductant concentrations, substrate concentration, reaction pH and reaction temperature on the size, morphology and yield of the silver nanoparticles (AgNPs) synthesized using aqueous leaf extract of a medicinal plant Momordica charantia (Bitter guard). By means of UV-vis spectroscopy, XRD analysis, TEM analysis and Fluorescence analysis, it is observed that the reaction solution containing 10-3 M of AgNO3 of pH 5.3  +  10 ml of aqueous leaf extract at normal room temperature, was optimum for synthesis of stable, polydisperse, predominantly spherical AgNPs with average size of 12.15 nm. FT-IR and TEM studies confirmed the stability of AgNPs was due to the capping of phytoconstituents present in the leaf extract. The aqueous solution of leaf extract containing AgNPs showed remarkable catalytic activity towards degradation of methyl orange (MO) in aqueous medium.

  2. Increased antioxidant activity and polyphenol metabolites in methyl jasmonate treated mung bean (Vigna radiata sprouts

    Directory of Open Access Journals (Sweden)

    Li LI

    Full Text Available Abstract Mung bean sprouts are a popular health food both in China and worldwide. We determined the optimal concentration of exogenous methyl jasmonate (MeJA for the promotion of the sprouting in mung beans (Vigna radiata. The 1,1-diphenyl-2- picrylhydrazyl radical (DPPH scavenging test showed that MeJA application resulted in significantly improved antioxidant capacity in the sprouts 72 h later. Measurement of total polyphenols in MeJA-treated beans from 0 to 168 h, using Folin–Ciocalteu colorimetry, showed that the polyphenols changing was significantly correlated with antioxidant activity. The main polyphenols isovitexin, kaempferol-3-O-rutinoside, daidzein, genistein, isoquercitrin, p-coumaric acid, and caffeic acid were quantified using high-performance liquid chromatography (HPLC/QqQ MS and partial least squares discriminant analysis (PLS-DA. MeJA promoted the production of polyphenols, metabolites, and antioxidants in the sprouts; therefore, its use may allow sprouts to be prepared more quickly or increase their nutritional value.

  3. THE ROLE OF VALENCE AND METHYLATION STATE ON THE ACTIVITY OF ARSENIC DURING MITOSIS

    Science.gov (United States)

    Trivalent methylated arsenicals are much more potent DNA damaging agents, clastogens, and large deletion mutagens than are their inorganic and pentavalent counterparts. Previously we had noticed that many of the arsenicals induced "c-type" anaphases characteristic of spindle pois...

  4. 21 CFR 173.140 - Esterase-lipase derived from Mucor miehei.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Esterase-lipase derived from Mucor miehei. 173.140... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.140 Esterase-lipase derived from Mucor miehei. Esterase-lipase enzyme, consisting of enzyme derived from Mucor miehei var. Cooney et Emerson by...

  5. Impact of Stepwise NH2-Methylation of Triapine on the Physicochemical Properties, Anticancer Activity, and Resistance Circumvention.

    Science.gov (United States)

    Kowol, Christian R; Miklos, Walter; Pfaff, Sarah; Hager, Sonja; Kallus, Sebastian; Pelivan, Karla; Kubanik, Mario; Enyedy, Éva A; Berger, Walter; Heffeter, Petra; Keppler, Bernhard K

    2016-07-28

    One of the most promising classes of iron chelators are α-N-heterocyclic thiosemicarbazones with Triapine as the most prominent representative. In several clinical trials Triapine showed anticancer activity against hematological diseases, however, studies on solid tumors failed due to widely unknown reasons. Some years ago, it was recognized that "terminal dimethylation" of thiosemicarbazones can lead to a more than 100-fold increased activity, probably due to interactions with cellular copper depots. To better understand the structural requirements for the switch to nanomolar cytotoxicity, we systematically synthesized all eight possible N-methylated derivatives of Triapine and investigated their potential against Triapine-sensitive as well as -resistant cell lines. While only the "completely" methylated compound exerted nanomolar activity, the data revealed that all compounds with at least one N-dimethylation were not affected by acquired Triapine resistance. In addition, these compounds were highly synergistic with copper treatment accompanied by induction of reactive oxygen species and massive necrotic cell death.

  6. Methyl Salicylate Level Increase in Flax after Fusarium oxysporum Infection Is Associated with Phenylpropanoid Pathway Activation

    OpenAIRE

    Boba, Aleksandra; Kostyn, Kamil; Kostyn, Anna; Wojtasik, Wioleta; Dziadas, Mariusz; Preisner, Marta; Szopa, Jan; Kulma, Anna

    2017-01-01

    Flax (Linum usitatissimum) is a crop plant valued for its oil and fiber. Unfortunately, large losses in cultivation of this plant are caused by fungal infections, with Fusarium oxysporum being one of its most dangerous pathogens. Among the plant's defense strategies, changes in the expression of genes of the shikimate/phenylpropanoid/benzoate pathway and thus in phenolic contents occur. Among the benzoates, salicylic acid, and its methylated form methyl salicylate play an important role in re...

  7. O6-methylguanine-DNA methyltransferase activity is associated with response to alkylating agent therapy and with MGMT promoter methylation in glioblastoma and anaplastic glioma

    Science.gov (United States)

    Bobola, Michael S.; Alnoor, Mohammad; Chen, John Y.-S.; Kolstoe, Douglas D.; Silbergeld, Daniel L.; Rostomily, Robert C.; Blank, A.; Chamberlain, Marc C.; Silber, John R.

    2014-01-01

    Background CpG methylation in the O6-methylguanine-DNA methyltransferase (MGMT) promoter is associated with better outcome following alkylating agent chemotherapy in glioblastoma (GBM) and anaplastic glioma (AG). To what extent improved response reflects low or absent MGMT activity in glioma tissue has not been unequivocally assessed. This information is central to developing anti-resistance therapies. Methods We examined the relationship of MGMT activity in 91 GBMs and 84 AGs with progression-free survival (PFS) following alkylator therapy and with promoter methylation status determined by methylation-specific PCR (MSP). Results Cox regression analysis revealed that GBMs with high activity had a significantly greater risk for progression in dichotomous (P ≤ 0.001) and continuous (P ≤ 0.003) models, an association observed for different alkylator regimens, including concurrent chemo-radiation with temozolomide. Analysis of MGMT promoter methylation status in 47 of the GBMs revealed that methylated tumors had significantly lower activity (P ≤ 0.005) and longer PFS (P ≤ 0.036) compared to unmethylated tumors, despite overlapping activities. PFS was also significantly greater in methylated vs. unmethylated GBMs with comparable activity (P ≤ 0.005), and among unmethylated tumors with less than median activity (P ≤ 0.026), suggesting that mechanisms in addition to MGMT promote alkylator resistance. Similar associations of MGMT activity with PFS and promoter methylation status were observed for AGs. Conclusions Our results provide strong support for the hypotheses that MGMT activity promotes alkylator resistance and reflects promoter methylation status in malignant gliomas. General significance MGMT activity is an attractive target for anti-resistance therapy regardless of methylation status. PMID:25558448

  8. Prenatal polycyclic aromatic hydrocarbon, adiposity, peroxisome proliferator-activated receptor (PPAR γ methylation in offspring, grand-offspring mice.

    Directory of Open Access Journals (Sweden)

    Zhonghai Yan

    Full Text Available Greater levels of prenatal exposure to polycyclic aromatic hydrocarbon (PAH have been associated with childhood obesity in epidemiological studies. However, the underlying mechanisms are unclear.We hypothesized that prenatal PAH over-exposure during gestation would lead to weight gain and increased fat mass in offspring and grand-offspring mice. Further, we hypothesized that altered adipose gene expression and DNA methylation in genes important to adipocyte differentiation would be affected.Pregnant dams were exposed to a nebulized PAH mixture versus negative control aerosol 5 days a week, for 3 weeks. Body weight was recorded from postnatal day (PND 21 through PND60. Body composition, adipose cell size, gene expression of peroxisome proliferator-activated receptor (PPAR γ, CCAAT/enhancer-binding proteins (C/EBP α, cyclooxygenase (Cox-2, fatty acid synthase (FAS and adiponectin, and DNA methylation of PPAR γ, were assayed in both the offspring and grand-offspring adipose tissue.Offspring of dams exposed to greater PAH during gestation had increased weight, fat mass, as well as higher gene expression of PPAR γ, C/EBP α, Cox2, FAS and adiponectin and lower DNA methylation of PPAR γ. Similar differences in phenotype and DNA methylation extended through the grand-offspring mice.Greater prenatal PAH exposure was associated with increased weight, fat mass, adipose gene expression and epigenetic changes in progeny.

  9. Acidic-alkaline ferulic acid esterase from Chaetomium thermophilum var. dissitum: Molecular cloning and characterization of recombinant enzyme expressed in Pichia pastoris

    DEFF Research Database (Denmark)

    Dotsenko, Gleb; Tong, Xiaoxue; Pilgaard, Bo

    2016-01-01

    A novel ferulic acid esterase encoding gene CtFae, was successfully cloned from a highly esterase active strain of the thermophile ascomycetous fungus Chaetomium thermophilum var. dissitum; the gene was heterologously expressed in Pichia pastoris KM71H. The recombinant enzyme (CtFae) was purified...... to homogeneity and subsequently characterized. CtFae was active towards synthetic esters of ferulic, p-coumaric, and caffeic acids, as well as towards wide range of p-nitrophenyl substrates. Its temperature and pH optima were 55 °C and pH 6.0, respectively. Enzyme rare features were broad pH optimum, high...

  10. Structure-activity relationship of daptomycin analogues with substitution at (2S, 3R) 3-methyl glutamic acid position.

    Science.gov (United States)

    Lin, Du'an; Lam, Hiu Yung; Han, Wenbo; Cotroneo, Nicole; Pandya, Bhaumik A; Li, Xuechen

    2017-02-01

    Daptomycin is a highly effective lipopeptide antibiotic against Gram-positive pathogens. The presence of (2S, 3R) 3-methyl glutamic acid (mGlu) in daptomycin has been found to be important to the antibacterial activity. However the role of (2S, 3R) mGlu is yet to be revealed. Herein, we reported the syntheses of three daptomycin analogues with (2S, 3R) mGlu substituted by (2S, 3R) methyl glutamine (mGln), dimethyl glutamic acid and (2S, 3R) ethyl glutamic acid (eGlu), respectively, and their antibacterial activities. The detailed synthesis of dimethyl glutamic acid was also reported. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Design, Synthesis and Antitumor Activity of Novel 4-Methyl-(3'S,4'S-cis-khellactone Derivatives

    Directory of Open Access Journals (Sweden)

    Taigang Liang

    2013-04-01

    Full Text Available An asymmetric synthesis of a series of novel 4-methyl-(3'S,4'S-cis-khellactone derivatives 3a–o is reported for the first time. Their structures were confirmed by 1H-NMR, 13C-NMR and MS. Their cytotoxic activity was evaluated by the MTT assay against three selected human cancer cell lines: HEPG-2 (human liver carcinoma, SGC-7901 (human gastric carcinoma, LS174T (human colon carcinoma. Some compounds showed high inhibitory activity against these human cancer cell lines. Among them, compound 3a exhibited strong cytotoxicity, with IC50 values ranging from 8.51 to 29.65 μM. The results showed that 4-methyl-cis-khellactone derivatives with S,S configuration could be a potential antitumor agents.

  12. Cellular function of neuropathy target esterase in lysophosphatidylcholine action

    International Nuclear Information System (INIS)

    Vose, Sarah C.; Fujioka, Kazutoshi; Gulevich, Alex G.; Lin, Amy Y.; Holland, Nina T.; Casida, John E.

    2008-01-01

    Neuropathy target esterase (NTE) plays critical roles in embryonic development and maintenance of peripheral axons. It is a secondary target of some organophosphorus toxicants including analogs of insecticides and chemical warfare agents. Although the mechanistic role of NTE in vivo is poorly defined, it is known to hydrolyze lysophosphatidylcholine (LPC) in vitro and may protect cell membranes from cytotoxic accumulation of LPC. To determine the cellular function of NTE, Neuro-2a and COS-7 cells were transfected with a full-length human NTE-containing plasmid yielding recombinant NTE (rNTE). We find the same inhibitor sensitivity and specificity profiles for rNTE assayed with LPC or phenyl valerate (a standard NTE substrate) and that this correlation extends to the LPC hydrolases of human brain, lymphocytes and erythrocytes. All of these LPC hydrolases are therefore very similar to each other in respect to a conserved inhibitor binding site conformation. NTE is expressed in brain and lymphocytes and contributes to LPC hydrolase activities in these tissues. The enzyme or enzymes responsible for erythrocyte LPC hydrolase activity remain to be identified. We also show that rNTE protects Neuro-2a and COS-7 cells from exogenous LPC cytotoxicity. Expression of rNTE in Neuro-2a cells alters their phospholipid balance (analyzed by liquid chromatography-mass spectrometry with single ion monitoring) by lowering LPC-16:0 and LPC-18:0 and elevating glycerophosphocholine without a change in phosphatidylcholine-16:0/18:1 or 16:0/18:2. NTE therefore serves an important function in LPC homeostasis and action

  13. Behaviour of Some Activated Nitriles Toward Barbituric Acid, Thiobarbituric Acid and 3-Methyl-1-Phenylpyrazol-5-one

    Directory of Open Access Journals (Sweden)

    M. M. Habashy

    2000-05-01

    Full Text Available The effect of some active methylene containing heterocyclic compounds, namely barbituric acid, thiobarbituric acid and 3-methyl-1-phenylpyrazol-5-one on a-cyano-3,4,5-trimethoxycinnamonitrile and ethyl a-cyano-3,4,5-trimethoxycinnamate (1a,b was investigated. The structure of the new products was substantiated by their IR,1H-NMR and mass spectra.

  14. Molecular cloning and characterization of a novel pyrethroid-hydrolyzing esterase originating from the Metagenome

    Directory of Open Access Journals (Sweden)

    Liu Yu

    2008-12-01

    Full Text Available Abstract Background Pyrethroids and pyrethrins are widely used insecticides. Extensive applications not only result in pest resistance to these insecticides, but also may lead to environmental issues and human exposure. Numerous studies have shown that very high exposure to pyrethroids might cause potential problems to man and aquatic organisms. Therefore, it is important to develop a rapid and efficient disposal process to eliminate or minimize contamination of surface water, groundwater and agricultural products by pyrethroid insecticides. Bioremediation is considered to be a reliable and cost-effective technique for pesticides abatement and a major factor determining the fate of pyrethroid pesticides in the environment, and suitable esterase is expected to be useful for potential application for detoxification of pyrethroid residues. Soil is a complex environment considered as one of the main reservoirs of microbial diversity on the planet. However, most of the microorganisms in nature are inaccessible as they are uncultivable in the laboratory. Metagenomic approaches provide a powerful tool for accessing novel valuable genetic resources (novel enzymes and developing various biotechnological applications. Results The pyrethroid pesticides residues on foods and the environmental contamination are a public safety concern. Pretreatment with pyrethroid-hydrolyzing esterase has the potential to alleviate the conditions. To this end, a pyrethroid-hydrolyzing esterase gene was successfully cloned using metagenomic DNA combined with activity-based functional screening from soil, sequence analysis of the DNA responsible for the pye3 gene revealed an open reading frame of 819 bp encoding for a protein of 272 amino acid residues. Extensive multiple sequence alignments of the deduced amino acid of Pye3 with the most homologous carboxylesterases revealed moderate identity (45–49%. The recombinant Pye3 was heterologously expressed in E. coli BL21(DE3

  15. Molecular characterization of a novel family VIII esterase from burkholderia multivorans UWC10

    CSIR Research Space (South Africa)

    Rashamuse, KJ

    2007-02-01

    Full Text Available et al., 1992). Here we report the cloning, purification, and 3D model of a novel family VIII esterase from Burkholderia multivorans UWC10. To our knowledge no report of esterolytic activity from B. multivorans is currently available. METHODOLOGY... stream_source_info Rashamuse1_2007_d.pdf.txt stream_content_type text/plain stream_size 9884 Content-Encoding UTF-8 stream_name Rashamuse1_2007_d.pdf.txt Content-Type text/plain; charset=UTF-8 Molecular Characterization...

  16. Solubilization, partial purification, and reconstitution of glutamate- and N-methyl-D-aspartate-activated cation channels from brain synaptic membranes

    International Nuclear Information System (INIS)

    Ly, A.M.; Michaelis, E.K.

    1991-01-01

    L-Glutamate-activated cation channel proteins from rat brain synaptic membranes were solubilized, partially purified, and reconstituted into liposomes. Optimal conditions for solubilization and reconstitution included treatment of the membranes with nonionic detergents in the presence of neutral phospholipids plus glycerol. Quench-flow procedures were developed to characterize the rapid kinetics of ion flux induced by receptor agonists. [ 14 C]Methylamine, a cation that permeates through the open channel of both vertebrate and invertebrate glutamate receptors, was used to measure the activity of glutamate receptor-ion channel complexes in reconstituted liposomes. L-Glutamate caused an increase in the rate of [ 14 C]methylamine influx into liposomes reconstituted with either solubilized membrane proteins or partially purified glutamate-binding proteins. Of the major glutamate receptor agonists, only N-methyl-D-aspartate activated cation fluxes in liposomes reconstituted with glutamate-binding proteins. In liposomes reconstituted with glutamate-binding proteins, N-methyl-D-aspartate- or glutamate-induced influx of NA + led to a transient increase in the influx of the lipid-permeable anion probe S 14 CN - . These results indicate the functional reconstitution of N-methyl-D-aspartate-sensitive glutamate receptors and the role of the ∼69-kDa protein in the function of these ion channels

  17. A feruloyl esterase derived from a leachate metagenome library

    CSIR Research Space (South Africa)

    Rashamuse, K

    2012-01-01

    Full Text Available A feruloyl esterase encoding gene (designated fae6), derived from a leachate metagenomic library, was cloned and the nucleotide sequence of the insert DNA determined. Translational analysis revealed that fae6 consists of a 515 amino acid polypeptide...

  18. New cholesterol esterase inhibitors based on rhodanine and thiazolidinedione scaffolds

    DEFF Research Database (Denmark)

    Heng, Sabrina; Tieu, William; Hautmann, Stephanie

    2011-01-01

    We present a new class of inhibitors of pancreatic cholesterol esterase (CEase) based on 'priviledged' 5-benzylidenerhodanine and 5-benzylidene-2,4-thiazolidinedione structural scaffolds. The lead structures (5-benzylidenerhodanine 4a and 5-benzylidene-2,4-thiazolidinedione 4b) were identified in...

  19. Reactions of 3-Formylchromone with Active Methylene and Methyl Compounds and Some Subsequent Reactions of the Resulting Condensation Products

    Directory of Open Access Journals (Sweden)

    M. Lácova

    2005-08-01

    Full Text Available This review presents a survey of the condensations of 3-formylchromone with various active methylene and methyl compounds, e.g. malonic or barbituric acid derivatives, five-membered heterocycles, etc. The utilisation of the condensation products for the synthesis of different heterocyclic systems, which is based on the ability of the γ-pyrone ring to be opened by the nucleophilic attack is also reviewed. Finally, the applications of microwave irradiation as an unconventional method of reaction activation in the synthesis of condensation products is described and the biological activity of some chromone derivatives is noted.

  20. Inhibition of aromatase activity by methyl sulfonyl PCB metabolites in primary culture of human mammary fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M. van den; Heneweer, M.; Geest, M. de; Sanderson, T. [Inst. for Risk Assessment Sciences and Utrecht Univ. (Netherlands); Jong, P. de [St. Antonius Hospital, Nieuwegein (Netherlands); Bergman, A. [Stockholm Univ., Stockholm (Sweden)

    2004-09-15

    Methyl sulfonyl PCB metabolites (MeSO2-PCBs) are persistent contaminants and are ubiquitously present in humans and the environment. Lipophilicity of MeSO2- PCB metabolites is similar to the parent compounds and they have been detected in human milk, adipose, liver and lung tissue. 4- MeSO2-PCB-149 is the most abundant PCB metabolite in human adipose tissue and milk at a level of 1.5 ng/g lipids. Human blood concentration of 4-MeSO2-PCB-149 is approximately 0.03 nM. 3- MeSO2-PCB-101 is the predominant PCB metabolite in muscle and blubber in wildlife, such as otter, mink and grey seal. In the environment, they have been linked to chronic and reproductive toxicity in exposed mink. Additionaly, some MeSO{sub 2}-PCBs have been shown to be glucocorticoid receptor (GR) antagonists. Since approximately 60% of all breast tumors are estrogen responsive, exposure to compounds that are able to alter estrogen synthesis through interference with the aromatase enzyme, can lead to changes in estrogen levels and possibly to accelerated or inhibit breast tumor growth. Therefore, it is important to identify exogenous compounds that can alter aromatase activity in addition to those compounds which have direct interaction with the estrogen receptor (ER). Aromatase (CYP19) comprises the ubiquitous flavoprotein, NADPH-cytochrome P450 reductase, and a unique cytochrome P450 that is exclusively expressed in estrogen producing cells. Previous studies have revealed that expression of the aromatase gene is regulated in a species- and tissue specific manner. In healthy breast tissue, the predominantly active aromatase promoter region I.4 is regulated by glucocorticoids and class I cytokines. Therefore, it is important to investigate possible aromatase inhibiting properties of MeSO{sub 2}-PCBs (as anti glucocorticoids?) in relevant human tissues. We used primary human mammary fibroblasts because of their role in breast cancer development. We compared the results in primary fibroblasts with

  1. Esterase polymorphism marking cultivars of Manihot esculenta, Crantz

    Directory of Open Access Journals (Sweden)

    Adriana Gazoli Resende

    2004-07-01

    Full Text Available Esterase isozymes were used to detected substrate-preference polymorphism in twenty cultivars of Manihot esculenta, and to show cultivar-specific variation of this species. A relatively complex extraction solution of proteins from leaves was needed to show a larger number of esterase isozymes. Similarity between cultivars from six groups ranged from 51 to 96%. The cultivars identified by the same name seemed to be biochemically different regarding esterase isozymes. Esterase isozyme electrophoretic patterns could, therefore, be used to discriminate the cultivars identified by the same name, and to monitor the vegetative propagation of cultivars maintained in the germplasm collection. In breeding strategies, isoesterase analysis could be used to avoid intercrossing between the similar genotypes.Isoenzimas esterases foram usadas no presente estudo, para detectar polimorfismos específicos para diferentes substratos em vinte cultivares de Manihot esculenta, e para mostrar variações específicas de cultivares nesta espécie. Os diferentes cultivares de M. esculenta tem sido mantidos na coleção de germoplasma do Departamento de Agronomia da Universidade Estadual de Maringá (Maringá, PR, e foram provenientes de cultivares tradicionais coletados nas regiões sudoeste e noroeste do Estado. Foi necessário a utilização de uma solução de extração de proteínas relativamente mais complexa, para evidenciar um maior número de isoenzimas esterases. A similaridade entre os cultivares variou de 51 a 96%. Cultivares identificados pelo mesmo nome parecem ser bioquimicamente diferentes para as isoenzimas esterases. Os padrões eletroforéticos das isoesterases podem, portanto, serem usados para discriminar os cultivares que são identificados pelo mesmo nome, e para monitorar a propagação vegetativa dos cultivares mantidos na coleção de germoplasma. A análise das isoesterases pode também ser usada para evitar cruzamentos entre genótipos mais

  2. Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta)

    International Nuclear Information System (INIS)

    Hannam, Marie L.; Hagger, Josephine A.; Jones, Malcolm B.; Galloway, Tamara S.

    2008-01-01

    Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC 50 of 5 μg l -1 for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 μg l -1 azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F = 2.75, P = 0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F = 15.33, P < 0.001). Whilst causality cannot be directly attributed from these latter exposures, they provide an important illustration of the potential utility of esterase activity as a biomarker of environmental quality in this ecologically relevant sentinel species. - This paper provides a preliminary characterisation of esterase enzyme activities in the tissues and body fluids of the sediment dwelling worm Arenicola marina and explores their potential use as biomarkers of organophosphorus pesticide exposure in the marine environment

  3. Characterisation of esterases as potential biomarkers of pesticide exposure in the lugworm Arenicola marina (Annelida: Polychaeta)

    Energy Technology Data Exchange (ETDEWEB)

    Hannam, Marie L. [Ecotoxicology and Stress Biology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA (United Kingdom)], E-mail: marie.hannam@plymouth.ac.uk; Hagger, Josephine A.; Jones, Malcolm B.; Galloway, Tamara S. [Ecotoxicology and Stress Biology Research Centre, School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA (United Kingdom)

    2008-03-15

    Here, we identify and characterise cholinesterase (ChE) and carboxylesterase (CbE) activities in the body tissues of the sediment dwelling worm Arenicola marina. Exposure to the organophosphorus pesticide azamethiphos yielded an in vitro IC{sub 50} of 5 {mu}g l{sup -1} for propionylcholinesterase (PChE). PChE was significantly inhibited in vivo after a 10 day exposure to 100 {mu}g l{sup -1} azamethiphos, equivalent to the recommended aquatic application rate (ANOVA; F = 2.75, P = 0.033). To determine sensitivity to environmental conditions, A. marina were exposed for 10 days to field collected sediments. PChE activity was significantly lower in worms exposed to sediments from an estuary classified to be at high risk from point source pollution by the UK Environment Agency (ANOVA; F = 15.33, P < 0.001). Whilst causality cannot be directly attributed from these latter exposures, they provide an important illustration of the potential utility of esterase activity as a biomarker of environmental quality in this ecologically relevant sentinel species. - This paper provides a preliminary characterisation of esterase enzyme activities in the tissues and body fluids of the sediment dwelling worm Arenicola marina and explores their potential use as biomarkers of organophosphorus pesticide exposure in the marine environment.

  4. Isolation and characterization of a heavy metal-resistant, thermophilic esterase from a Red Sea Brine Pool

    KAUST Repository

    Mohamed, Yasmine M.; Ghazy, Mohamed A.; Sayed, Ahmed; Ouf, Amged; El-Dorry, Hamza; Siam, Rania

    2013-01-01

    The Red Sea Atlantis II brine pool is an extreme environment that displays multiple harsh conditions such as high temperature, high salinity and high concentrations of multiple, toxic heavy metals. The survival of microbes in such an environment by utilizing resistant enzymes makes them an excellent source of extremophilic enzymes. We constructed a fosmid metagenomic library using DNA isolated from the deepest and most secluded layer of this pool. We report the isolation and biochemical characterization of an unusual esterase: EstATII. EstATII is thermophilic (optimum temperature, 65 C), halotolerant (maintains its activity in up to 4.5â€...M NaCl) and maintains at least 60% of its activity in the presence of a wide spectrum of heavy metals. The combination of biochemical characteristics of the Red Sea Atlantis II brine pool esterase, i.e., halotolerance, thermophilicity and resistance to heavy metals, makes it a potentially useful biocatalyst.

  5. Isolation and characterization of a heavy metal-resistant, thermophilic esterase from a Red Sea Brine Pool

    KAUST Repository

    Mohamed, Yasmine M.

    2013-11-28

    The Red Sea Atlantis II brine pool is an extreme environment that displays multiple harsh conditions such as high temperature, high salinity and high concentrations of multiple, toxic heavy metals. The survival of microbes in such an environment by utilizing resistant enzymes makes them an excellent source of extremophilic enzymes. We constructed a fosmid metagenomic library using DNA isolated from the deepest and most secluded layer of this pool. We report the isolation and biochemical characterization of an unusual esterase: EstATII. EstATII is thermophilic (optimum temperature, 65 C), halotolerant (maintains its activity in up to 4.5â€...M NaCl) and maintains at least 60% of its activity in the presence of a wide spectrum of heavy metals. The combination of biochemical characteristics of the Red Sea Atlantis II brine pool esterase, i.e., halotolerance, thermophilicity and resistance to heavy metals, makes it a potentially useful biocatalyst.

  6. Ionizing radiation-induced modulation of activities of the enzymes involved in DNA methylation

    International Nuclear Information System (INIS)

    Batra, Vipen; Kesavan, V.; Mishra, K.P.

    2004-01-01

    Studies have indicated that radiation might create a state of folate insufficiency by mobilization of cellular folate in DNA repair pathways. The present result indicates an optimization between methylation reaction versus deoxithymidylate synthesis took place in vivo after whole body irradiation as both the reaction depended upon folate, which possibly was a limiting factor under radiation stress

  7. Biosynthesis of estragole and methyl-eugenol in sweet basil (Ocimum basilicum L). Developmental and chemotypic association of allylphenol O-methyltransferase activities.

    Science.gov (United States)

    Lewinsohn, E; Ziv-Raz, I; Dudai, N; Tadmor, Y; Lastochkin, E; Larkov, O; Chaimovitsh, D; Ravid, U; Putievsky, E; Pichersky, E; Shoham, Y

    2000-12-07

    Sweet basil (Ocimum basilicum L., Lamiaceae) is a common herb, used for culinary and medicinal purposes. The essential oils of different sweet basil chemotypes contain various proportions of the allyl phenol derivatives estragole (methyl chavicol), eugenol, and methyl eugenol, as well as the monoterpene alcohol linalool. To monitor the developmental regulation of estragole biosynthesis in sweet basil, an enzymatic assay for S-adenosyl-L-methionine (SAM):chavicol O-methyltransferase activity was developed. Young leaves display high levels of chavicol O-methyltransferase activity, but the activity was negligible in older leaves, indicating that the O-methylation of chavicol primarily occurs early during leaf development. The O-methyltransferase activities detected in different sweet basil genotypes differed in their substrate specificities towards the methyl acceptor substrate. In the high-estragole-containing chemotype R3, the O-methyltransferase activity was highly specific for chavicol, while eugenol was virtually not O-methylated. In contrast, chemotype 147/97, that contains equal levels of estragole and methyl eugenol, displayed O-methyltransferase activities that accepted both chavicol and eugenol as substrates, generating estragole and methyl eugenol, respectively. Chemotype SW that contains high levels of eugenol, but lacks both estragole and methyl eugenol, had apparently no allylphenol dependent O-methyltransferase activities. These results indicate the presence of at least two types of allylphenol-specific O-methyltransferase activities in sweet basil chemotypes, one highly specific for chavicol; and a different one that can accept eugenol as a substrate. The relative availability and substrate specificities of these O-methyltransferase activities biochemically rationalizes the variation in the composition of the essential oils of these chemotypes.

  8. Effect of O-methylated and glucuronosylated flavonoids from Tamarix gallica on α-glucosidase inhibitory activity: structure-activity relationship and synergistic potential.

    Science.gov (United States)

    Ben Hmidene, Asma; Smaoui, Abderrazak; Abdelly, Chedly; Isoda, Hiroko; Shigemori, Hideyuki

    2017-03-01

    O-Methylated and glucuronosylated flavonoids were isolated from Tamarix gallica as α-glucosidase inhibitors. Structure-activity relationship of these flavonoids suggests that catechol moiety and glucuronic acid at C-3 are factors in the increase in α-glucosidase inhibitory activity. Furthermore, rhamnetin, tamarixetin, rhamnazin, KGlcA, KGlcA-Me, QGlcA, and QGlcA-Me exhibit synergistic potential when applied with a very low concentration of acarbose to α-glucosidase from rat intestine.

  9. Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuting, E-mail: wuyuting1302@sina.com; Bu, Fangtian; Yu, Haixia; Li, Wanxia; Huang, Cheng; Meng, Xiaoming; Zhang, Lei; Ma, Taotao; Li, Jun, E-mail: lj@ahmu.edu.cn

    2017-01-15

    Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP) analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. - Highlights: • This is the first report of Sept9 methylation and function in liver fibrosis. • Ectopic expression of Sept9 could block the liver fibrogenesis. • DNMT3a might be responsible for the suppression of Sept9 in liver fibrosis.

  10. Methylation of Septin9 mediated by DNMT3a enhances hepatic stellate cells activation and liver fibrogenesis

    International Nuclear Information System (INIS)

    Wu, Yuting; Bu, Fangtian; Yu, Haixia; Li, Wanxia; Huang, Cheng; Meng, Xiaoming; Zhang, Lei; Ma, Taotao; Li, Jun

    2017-01-01

    Liver fibrosis, resulting from chronic and persistent injury to the liver, is a worldwide health problem. Advanced liver fibrosis results in cirrhosis, liver failure and even hepatocellular cancer (HCC), often eventually requiring liver transplantation, poses a huge health burden on the global community. However, the specific pathogenesis of liver fibrosis remains not fully understood. Numerous basic and clinical studies have provided evidence that epigenetic modifications, especially DNA methylation, might contribute to the activation of hepatic stellate cells (HSCs), the pivotal cell type responsible for the fibrous scar in liver. Here, reduced representation bisulfite sequencing (RRBS) and bisulfite pyrosequencing PCR (BSP) analysis identified hypermethylation status of Septin9 (Sept9) gene in liver fibrogenesis. Sept9 protein was dramatically decreased in livers of CCl4-treated mice and immortalized HSC-T6 cells exposed to TGF-β1. Nevertheless, the suppression of Sept9 could be blocked by DNMT3a-siRNA and DNA methyltransferase inhibitor, 5-aza-2′-deoxycytidine (5-azadC). Overexpressed Sept9 attenuated TGF-β1-induced expression of myofibroblast markers α-SMA and Col1a1, accompanied by up-regulation of cell apoptosis-related proteins. Conversely, RNAi-mediated silencing of Sept9 enhanced accumulation of extracellular matrix. These observations suggested that Sept9 contributed to alleviate liver fibrosis might partially through promoting activated HSCs apoptosis and this anti-fibrogenesis effect might be blocked by DNMT-3a mediated methylation of Sept9. Therefore, pharmacological agents that inhibit Sept9 methylation and increase its expression could be considered as valuable treatments for liver fibrosis. - Highlights: • This is the first report of Sept9 methylation and function in liver fibrosis. • Ectopic expression of Sept9 could block the liver fibrogenesis. • DNMT3a might be responsible for the suppression of Sept9 in liver fibrosis.

  11. Method of preparing [methyl-3H]thymine and 5-hydroxy[3H]methyluracil mixture of high molar activity

    International Nuclear Information System (INIS)

    Filip, J.; Bohacek, L.

    1981-01-01

    Non-active 5-formyluracil dissolved in 0.01 N to 1.0 N of hydrochloric acid is acted upon by gaseous carrier-free tritium at room temperature in the presence of a heterogeneous palladium/carrier catalyst, with advantage palladium on barium sulfate. The described procedure allows the preparation of [methyl- 3 H]thymine on a microscale, with a high molar activity in a single reaction stage with a high chemical (50-70%) and radiochemical (15-25%) yield. (J.P.)

  12. DNA methylation in porcine preimplantation embryos developed in vivo and produced by in vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer

    DEFF Research Database (Denmark)

    Deshmukh, Rahul Shahaji; Østrup, Olga; Østrup, Esben

    2011-01-01

    DNA demethylation and remethylation are crucial for reprogramming of the differentiated parental/somatic genome in the recipient ooplasm upon somatic cell nuclear transfer. Here, we analyzed the DNA methylation dynamics during porcine preimplantation development. Porcine in vivo developed (IV......), in vitro fertilized (IVF), somatic cell nuclear transfer (SCNT) and parthenogenetically activated (PA) embryos were evaluated for DNA methylation quantification at different developmental stages. Fertilized (IV and IVF) one-cell stages lacked a substantial active demethylation of the paternal genome...

  13. DNA methylation in porcine preimplantation embryos developed in-vivo or produced by in-vitro fertilization, parthenogenetic activation and somatic cell nuclear transfer

    DEFF Research Database (Denmark)

    Deshmukh, Rahul Shahaji; Østrup, Olga; Østrup, Esben

    2011-01-01

    DNA demethylation and remethylation are crucial for reprogramming of the differentiated parental/somatic genome in the recipient ooplasm upon somatic cell nuclear transfer. Here, we analyzed the DNA methylation dynamics during porcine preimplantation development. Porcine in vivo developed (IV......), in vitro fertilized (IVF), somatic cell nuclear transfer (SCNT) and parthenogenetically activated (PA) embryos were evaluated for DNA methylation quantification at different developmental stages. Fertilized (IV and IVF) one-cell stages lacked a substantial active demethylation of the paternal genome...

  14. Increased intragenic IGF2 methylation is associated with repression of insulator activity and elevated expression in serous ovarian carcinoma

    Directory of Open Access Journals (Sweden)

    Zhiqing eHuang

    2013-05-01

    Full Text Available Overexpression of insulin-like growth factor-II (IGF2 is a prominent characteristic of many epithelial ovarian malignancies. IGF2 imprinting and transcription are regulated in part through DNA methylation, which in turn regulates binding of the insulator protein, CTCF, within the IGF2/H19 imprint center. We have shown that IGF2 overexpression in ovarian cancer is associated with hypermethylation of CTCF binding sites within the IGF2/H19 imprint center. The aim of this study was to investigate the methylation and binding capacity of a novel putative CTCF binding motif located intragenic to IGF2 and determine how this relates to IGF2 expression. In 35 primary serous epithelial ovarian cancer specimens, methylation of two CpGs, including one within the core binding motif and another adjacent to this motif, was higher in the 18 cancers with elevated IGF2 expression versus 10 with low expression (avg. 68.2% vs. 38.5%; p<0.0001. We also found that the CpG site within the CTCF binding motif is hypermethylated in male gametes (>92%; avg. 93.2%; N=16. We confirmed binding of CTCF to this region in ovarian cancer cells, as well as the paralog of CTCF, BORIS, which is frequently overexpressed in cancers. The unmethylated CTCF binding motif has insulator activity in cells that express CTCF or BORIS, but not in cells that express both CTCF and BORIS. These intragenic CpG dinucleotides comprise a novel paternal germline imprint mark and are located in a binding motif for the insulator protein CTCF. Methylation of the CpG dinucleotides is positively correlated with IGF2 transcription, supporting that increased methylation represses insulator function. These combined results suggest that methylation and CTCF binding at this region play important roles in regulating the level of IGF2 transcription. Our data have revealed a novel epigenetic regulatory element within the IGF2/H19 imprinted domain that is highly relevant to aberrant IGF2 expression in ovarian

  15. Improved stability and enhanced efficiency to degrade chlorimuron-ethyl by the entrapment of esterase SulE in cross-linked poly (γ-glutamic acid)/gelatin hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liqiang [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China); University of Chinese Academy of Sciences, Beijing (China); Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Xu, MingKai [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China); Zhang, Huiwen, E-mail: hwzhang@iae.ac.cn [State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang (China)

    2015-04-28

    Highlights: • Esterase SulE was entrapped in a three-dimensional network of CPE. • CPE-SulE obviously improved thermostability, pH stability and reusability. • CPE-SulE displayed obviously enhanced efficiency in degrading chlorimuron-ethyl. • The three-dimensional network and kinetic parameters of CPE-SulE were analysed. • CPE-SulE possesses the great potential to remediate chlorimuron-ethyl contaminated in situ. - Abstract: Free enzymes often undergo some problems such as easy deactivation, low stability, and less recycling in biodegradation processes, especially in soil condition. A novel esterase SulE, which is responsible for primary degradation of a wide range of sulfonylurea herbicides by methyl or ethyl ester de-esterification, was expressed by strain Hansschlegelia sp. CHL1 and entrapped for the first time in an environment-friendly, biocompatible and biodegradable cross-linked poly (γ-glutamic acid)/gelatin hydrogel (CPE). The activity and stability of CPE-SulE were compared with free SulE under varying pH and temperature condition by measuring chlorimuron-ethyl residue. Meanwhile, the three-dimensional network of CPE-SulE was verified by scanning electron microscopy (SEM). The results showed that CPE-SulE obviously improved thermostability, pH stability and reusability compared with free SulE. Furthermore, CPE-SulE enhanced degrading efficiency of chlorimuron-ethyl in both soil and water system, especially in acid environment. The characteristics of CPE-SulE suggested the great potential to remediate chlorimuron-ethyl contaminated soils in situ.

  16. Improved stability and enhanced efficiency to degrade chlorimuron-ethyl by the entrapment of esterase SulE in cross-linked poly (γ-glutamic acid)/gelatin hydrogel

    International Nuclear Information System (INIS)

    Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Xu, MingKai; Zhang, Huiwen

    2015-01-01

    Highlights: • Esterase SulE was entrapped in a three-dimensional network of CPE. • CPE-SulE obviously improved thermostability, pH stability and reusability. • CPE-SulE displayed obviously enhanced efficiency in degrading chlorimuron-ethyl. • The three-dimensional network and kinetic parameters of CPE-SulE were analysed. • CPE-SulE possesses the great potential to remediate chlorimuron-ethyl contaminated in situ. - Abstract: Free enzymes often undergo some problems such as easy deactivation, low stability, and less recycling in biodegradation processes, especially in soil condition. A novel esterase SulE, which is responsible for primary degradation of a wide range of sulfonylurea herbicides by methyl or ethyl ester de-esterification, was expressed by strain Hansschlegelia sp. CHL1 and entrapped for the first time in an environment-friendly, biocompatible and biodegradable cross-linked poly (γ-glutamic acid)/gelatin hydrogel (CPE). The activity and stability of CPE-SulE were compared with free SulE under varying pH and temperature condition by measuring chlorimuron-ethyl residue. Meanwhile, the three-dimensional network of CPE-SulE was verified by scanning electron microscopy (SEM). The results showed that CPE-SulE obviously improved thermostability, pH stability and reusability compared with free SulE. Furthermore, CPE-SulE enhanced degrading efficiency of chlorimuron-ethyl in both soil and water system, especially in acid environment. The characteristics of CPE-SulE suggested the great potential to remediate chlorimuron-ethyl contaminated soils in situ

  17. B-type esterases in the snail Xeropicta derbentina: An enzymological analysis to evaluate their use as biomarkers of pesticide exposure

    Energy Technology Data Exchange (ETDEWEB)

    Laguerre, Christel [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France); Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo (Spain); Koehler, Heinz R. [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Strasse 20, D-72072 Tuebingen (Germany); Triebskorn, Rita [Animal Physiological Ecology, University of Tuebingen, Konrad-Adenauer-Strasse 20, D-72072 Tuebingen (Germany); Steinbeis-Transfer Center for Ecotoxicology and Ecophysiology, Blumenstrasse 13, D-72108 Rottenburg (Germany); Capowiez, Yvan [INRA, Unite PSH, F- 84914 Avignon (France); Rault, Magali [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France); Mazzia, Christophe [Universite d' Avignon et des Pays de Vaucluse, UMR 406 UAPV/INRA, F-84914 Avignon (France); INRA, Laboratoire de Toxicologie Environnementale, UMR 406 UAPV/INRA, F-84914 Avignon (France)], E-mail: mazzia@avignon.inra.fr

    2009-01-15

    The study was prompted to characterize the B-type esterase activities in the terrestrial snail Xeropicta derbentina and to evaluate its sensitivity to organophosphorus and carbamate pesticides. Specific cholinesterase and carboxylesterase activities were mainly obtained with acetylthiocholine (K{sub m} = 77.2 mM; V{sub max} = 38.2 mU/mg protein) and 1-naphthyl acetate (K{sub m} = 222 mM, V{sub max} = 1095 mU/mg protein) substrates, respectively. Acetylcholinesterase activity was concentration-dependently inhibited by chlorpyrifos-oxon, dichlorvos, carbaryl and carbofuran (IC50 = 1.35 x 10{sup -5}-3.80 x 10{sup -8} M). The organophosphate-inhibited acetylcholinesterase activity was reactivated in the presence of pyridine-2-aldoxime methochloride. Carboxylesterase activity was inhibited by organophosphorus insecticides (IC50 = 1.20 x 10{sup -5}-2.98 x 10{sup -8} M) but not by carbamates. B-esterase-specific differences in the inhibition by organophosphates and carbamates are discussed with respect to the buffering capacity of the carboxylesterase to reduce pesticide toxicity. These results suggest that B-type esterases in X. derbentina are suitable biomarkers of pesticide exposure and that this snail could be used as sentinel species in field monitoring of Mediterranean climate regions. - Characterization of the B-type esterases in the terrestrial snail Xeropicta derbentina in order to evaluate pesticide exposure.

  18. Whole-Cell Biocatalytic Synthesis of Cinnamyl Acetate with a Novel Esterase from the DNA Library of Acinetobacter hemolyticus.

    Science.gov (United States)

    Dong, Hao; Secundo, Francesco; Xue, Changhu; Mao, Xiangzhao

    2017-03-15

    Cinnamyl acetate has a wide application in the flavor and fragrance industry because of its sweet, balsamic, and floral odor. Up to now, lipases have been mainly used in enzyme-mediated synthesis of cinnamyl acetate, whereas esterases are used in only a few cases. Moreover, the use of purified enzymes is often a disadvantage, which leads to increases of the production costs. In this paper, a genomic DNA library of Acinetobacter hemolyticus was constructed, and a novel esterase (EstK1) was identified. After expression in Escherichia coli, the whole-cell catalyst of EstK1 displayed high transesterification activity to produce cinnamyl acetate in nonaqueous systems. Furthermore, under optimal conditions (vinyl acetate as acyl donor, isooctane as solvent, molar ratio 1:4, temperature 40 °C), the conversion ratio of cinnamyl alcohol could be up to 94.1% at 1 h, and it reached an even higher level (97.1%) at 2 h.

  19. Synthesis of SnO{sub 2}-activated carbon fiber hybrid catalyst for the removal of methyl violet from water

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jia, E-mail: mse_lij@ujn.edu.cn [School of Material Science and Engineering, University of Jinan, Jinan 250022 (China); Ng, Dickon H.L. [Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong (China); Song, Peng; Kong, Chao; Song, Yi [School of Material Science and Engineering, University of Jinan, Jinan 250022 (China)

    2015-04-15

    Graphical abstract: - Highlights: • A new biomass route for the synthesis of SnO{sub 2}/ACF hybrid catalyst was proposed. • The original fibrous structure of kapok fiber was retained in the SnO{sub 2}/ACF hybrid catalyst. • SnO{sub 2}/ACF hybrid catalyst exhibited high BET surface area (647–897 m{sup 2}/g) and large pore volume (0.36–0.56 cm{sup 3} g{sup −1}). • High microwave-induced catalytic activity for methyl violet degradation was obtained. - Abstract: SnO{sub 2}/activated carbon fiber (ACF) hybrid catalyst was synthesized from kapok precursor via a two-step process involving pore-fabricating and self-assembly of SnO{sub 2} nanoparticles. The morphology and phase structure of the obtained samples were characterized by X-ray diffraction, field emission scanning electron microscope, high resolution transmission electron microscopy and N{sub 2} adsorption-desorption isotherm. These results demonstrated that the synthesized SnO{sub 2}/ACF retained the hollow-fiber structure of kapok fibers. SnO{sub 2} nanoparticles dispersed uniformly over the ACF support. The obtained hybrid catalyst showed porous structure with high surface area (647–897 m{sup 2}/g) and large pore volume (0.36–0.56 cm{sup 3} g{sup −1}). In addition, the catalytic activities of the obtained samples for methyl violet degradation under microwave irradiation were also evaluated. It was found that the SnO{sub 2}/ACF catalyst exhibited high catalytic activity for methyl violet degradation due to the synergistic effect of microwave and SnO{sub 2}/ACF catalyst.

  20. Synthesis and Characterization of the Most Active Copper ATRP Catalyst Based on Tris[(4-dimethylaminopyridyl)methyl]amine.

    Science.gov (United States)

    Ribelli, Thomas G; Fantin, Marco; Daran, Jean-Claude; Augustine, Kyle F; Poli, Rinaldo; Matyjaszewski, Krzysztof

    2018-01-31

    The tris[(4-dimethylaminopyridyl)methyl]amine (TPMA NMe2 ) as a ligand for copper-catalyzed atom transfer radical polymerization (ATRP) is reported. In solution, the [Cu I (TPMA NMe2 )Br] complex shows fluxionality by variable-temperature NMR, indicating rapid ligand exchange. In the solid state, the [Cu II (TPMA NMe2 )Br][Br] complex exhibits a slightly distorted trigonal bipyramidal geometry (τ = 0.89). The UV-vis spectrum of [Cu II (TPMA NMe2 )Br] + salts is similar to those of other pyridine-based ATRP catalysts. Electrochemical studies of [Cu(TPMA NMe2 )] 2+ and [Cu(TPMA NMe2 )Br] + showed highly negative redox potentials (E 1/2 = -302 and -554 mV vs SCE, respectively), suggesting unprecedented ATRP catalytic activity. Cyclic voltammetry (CV) in the presence of methyl 2-bromopropionate (MBrP; acrylate mimic) was used to determine activation rate constant k a = 1.1 × 10 6 M -1 s -1 , confirming the extremely high catalyst reactivity. In the presence of the more active ethyl α-bromoisobutyrate (EBiB; methacrylate mimic), total catalysis was observed and an activation rate constant k a = 7.2 × 10 6 M -1 s -1 was calculated with values of K ATRP ≈ 1. ATRP of methyl acrylate showed a well-controlled polymerization using as little as 10 ppm of catalyst relative to monomer, while side reactions such as Cu I -catalyzed radical termination (CRT) could be suppressed due to the low concentration of L/Cu I at a steady state.

  1. CpG methylation suppresses transcriptional activity of human syncytin-1 in non-placental tissues

    Czech Academy of Sciences Publication Activity Database

    Matoušková, Magda; Blažková, Jana; Pajer, Petr; Pavlíček, Adam; Hejnar, Jiří

    2006-01-01

    Roč. 312, č. 7 (2006), s. 1011-1020 ISSN 0014-4827 R&D Projects: GA ČR(CZ) GA204/05/0939; GA AV ČR(CZ) IAA5052207 Institutional research plan: CEZ:AV0Z50520514 Keywords : syncytin-1 * trophoblast * DNA methylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.777, year: 2006

  2. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhang, Heyu; Nan, Xu; Li, Xuefen; Chen, Yan; Zhang, Jianyun; Sun, Lisha; Han, Wenlin; Li, Tiejun

    2014-01-01

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma

  3. CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Heyu [Central Laboratory, Peking University School of Stomatology, Beijing (China); Nan, Xu [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Xuefen [Central Laboratory, Peking University School of Stomatology, Beijing (China); Chen, Yan; Zhang, Jianyun [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China); Sun, Lisha [Central Laboratory, Peking University School of Stomatology, Beijing (China); Han, Wenlin [Center for Human Disease Genomics, Department of Immunology, Key Laboratory of Medical Immunology, Ministry of Health, School of Basic Medical Sciences, Peking University, Beijing (China); Li, Tiejun, E-mail: litiejun22@vip.sina.com [Department of Oral Pathology, Peking University School of Stomatology, Beijing (China)

    2014-05-02

    Highlights: • Down-regulation of CMTM5 expression in OSCC tissues was found. • The promoter methylation status of CMTM5 was measured. • CMTM5-v1 inhibited cell proliferation and migration and induced apoptosis. • CMTM5 might act as a putative tumor suppressor gene in OSCC. - Abstract: Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.

  4. Cloning and characterization of a pyrethroid pesticide decomposing esterase gene, Est3385, from Rhodopseudomonas palustris PSB-S.

    Science.gov (United States)

    Luo, Xiangwen; Zhang, Deyong; Zhou, Xuguo; Du, Jiao; Zhang, Songbai; Liu, Yong

    2018-05-09

    Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30-46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could detoxify various pyrethroid pesticides and degrade the optimal substrate fenpropathrin with a Km and Vmax value of 0.734 ± 0.013 mmol·l -1 and 0.918 ± 0.025 U·µg -1 , respectively. No cofactor was found to affect Est3385 activity but substantial reduction of enzymatic activity was observed when metal ions were applied. Taken together, a new pyrethroid degradation esterase was identified and characterized. Modification of Est3385 with protein engineering toolsets should enhance its potential for field application to reduce the pesticide residue from agroecosystems.

  5. Damped Quantum Rotation of the Methyl Group in 9-Methyltriptycene Derivatives. The Magnitude of The Effect vs. The Activation Energy

    International Nuclear Information System (INIS)

    Czerski, I.; Szymanski, S.

    2005-01-01

    According to the damped quantum rotation (DQR) theory, hindered rotation of methyl groups, reflected in NMR spectra, is a quantum mechanical process controlled by two quantum mechanical rate constants k t and k K . The subscripts t and K, designating '' tunneling '' and '' Kramers '', refer to two specific, long-lived quantum coherence in the methyl rotor system each of which engages the space and spin coordinates of the three protons, correlated by the Pauli principle. Only in the instances where k t and k K happen to be equal, the NMR picture will be the same as for a hypothetical CH 3 group undergoing classical jumps between its three equivalent orientations, described by single rate constant k '. Departure of the ratio c = k t /k K from 1 can thus serve as a quick measure of the degree of non classicality in the stochastic dynamics of the methyl group or, in other words, of the magnitude of the DQR effect. When the Arrhenius activation energy, Ea, for k K is about 12 kJmol -1 , the non classicality factor c can exceed 5. This is an inference from our recent single-crystal NMR studies at temperatures 60 - 110 K. On an intuitive ground, there should be an inverse (but hardly linear) correlation between E a and c. Indeed, for strongly hindered methyl group in 9-methyltripticene derivatives for which the activation energies can exceed 37 kJmol -1 , the DQR effect proves to be much smaller, with the corresponding values of c not exceeding 1.20. Nonetheless, for the values of c above 1.10 it can still be clearly seen in liquid-phase NMR spectra. Here we report on our recent liquid-phase NMR experiments with a series of 9-methyltriptycene derivatives for which the values of E a for k K span the range 37.4 - 44.8 kJmol -1 while the respective, average values of c vary between 1.04 and 1.20. It comes out that, within such a narrow variability range of E a , the correlation between c and E a no longer holds. For example, for 1,2,3,4-tetrabromo-9,10-dimethyltriptycene

  6. Isolation, structure elucidation and antibacterial activity of methyl-4,8-dimethylundecanate from the marine actinobacterium Streptomyces albogriseolus ECR64.

    Science.gov (United States)

    Thirumurugan, Durairaj; Vijayakumar, Ramasamy; Vadivalagan, Chithravel; Karthika, Pushparaj; Alam Khan, Md Khurshid

    2018-05-25

    Around 120 actinobacterial colonies were isolated from various regions of marine East coast region of Tamil Nadu, India. Among them, 33 were morphologically distinct and they were preliminarily screened for their antibacterial activity against Pseudomonas fluorescens, Vibrio cholerae, V. parahaemolyticus, V. alginolyticus, and Aeromonas hydrophila by cross-streak plate technique. Among the isolated, the isolate ECR64 exhibited maximum zone of inhibition against fish pathogenic bacteria. The crude bioactive compounds were extracted from the isolate ECR64 using different organic solvents which exhibited maximum antibacterial activity. Separation and purification of the bioactive compounds were made by column chromatography which yielded 27 fractions and were re-chromatographed to obtain the active compound. Ultra violet (UV), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectral studies were used to predict the structure of the active compound which was identified as methyl-4,8-dimethylundecanate. The potential isolate ECR64 was identified as Streptomyces albogriseolus by phylogenetic, phenotypic and genotypic (16S rRNA gene sequence) analyses. The identified compound methyl-4,8-dimethylundecanate can be used as potential and alternative drug in disease management of aquaculture. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Overexpression of esterase D in kidney from trisomy 13 fetuses

    Energy Technology Data Exchange (ETDEWEB)

    Loughna, S.; Moore, G. (Institute of Obstetrics and Gynaecology, London (United Kingdom)); Gau, G.; Blunt, S. (Cytogenetics Lab., London (United Kingdom)); Nicolaides, K. (King' s College School of Medicine and Dentistry, London (United Kingdom))

    1993-10-01

    Human trisomy 13 (Patau syndrome) occurs in approximately 1 in 5,000 live births. It is compatible with life, but prolonged survival is rare. Anomalies often involve the urogenital, cardiac, craniofacial, and central nervous systems. It is possible that these abnormalities may be due to the overexpression of developmentally important genes on chromosome 13. The expression of esterase D (localized to chromosome 13q14.11) has been investigated in both muscle and kidney from trisomy 13 fetuses and has been compared with normal age- and sex-matched fetal tissues, by using northern analysis. More than a twofold increase in expression of esterase D was found in the kidney of two trisomy 13 fetuses, with normal levels in a third. Overexpression was not seen in the muscle tissues from these fetuses. 34 refs., 3 figs., 2 tabs.

  8. Leucocyte esterase in the rapid diagnosis of paediatric septic arthritis.

    LENUS (Irish Health Repository)

    Kelly, E G

    2013-02-01

    Septic arthritis may affect any age group but is more common in the paediatric population. Infection is generally bacterial in nature. Prompt diagnosis is crucial, as delayed treatment is associated with lifelong joint dysfunction. A clinical history and application of Kocher\\'s criteria may indicate that there is a septic arthritis. However, definitive diagnosis is made on culture of septic synovial fluid. The culture process can take over 24h for the initial culture to yield bacterial colonies. Leucocyte esterase is released by leucocytes at the site of an infection. We hypothesise that leucocyte esterase can be utilized in the rapid diagnosis of septic arthritis and shorten the time to decisive treatment whilst simultaneously decreasing unnecessary treatment of non-septic joints.

  9. Tet1 Oxidase Regulates Neuronal Gene Transcription, Active DNA Hydroxy-methylation, Object Location Memory, and Threat Recognition Memory.

    Science.gov (United States)

    Kumar, Dinesh; Aggarwal, Milan; Kaas, Garrett A; Lewis, John; Wang, Jing; Ross, Daniel L; Zhong, Chun; Kennedy, Andrew; Song, Hongjun; Sweatt, J David

    2015-10-01

    A dynamic equilibrium between DNA methylation and demethylation of neuronal activity-regulated genes is crucial for memory processes. However, the mechanisms underlying this equilibrium remain elusive. Tet1 oxidase has been shown to play a key role in the active DNA demethylation in the CNS. In this study, we used Tet1 gene knockout (Tet1KO) mice to examine the involvement of Tet1 in memory consolidation and storage in the adult brain. We found that Tet1 ablation leads to: altered expression of numerous neuronal activity-regulated genes, compensatory upregulation of active demethylation pathway genes, and upregulation of various epigenetic modifiers. Moreover, Tet1KO mice showed an enhancement in the consolidation and storage of threat recognition (cued and contextual fear conditioning) and object location memories. We conclude that Tet1 plays a critical role in regulating neuronal transcription and in maintaining the epigenetic state of the brain associated with memory consolidation and storage.

  10. DNA methylation in an enhancer region of the FADS cluster is associated with FADS activity in human liver.

    Directory of Open Access Journals (Sweden)

    Timothy D Howard

    Full Text Available Levels of omega-6 (n-6 and omega-3 (n-3, long chain polyunsaturated fatty acids (LcPUFAs such as arachidonic acid (AA; 20:4, n-6, eicosapentaenoic acid (EPA; 20:5, n-3 and docosahexaenoic acid (DHA; 22:6, n-3 impact a wide range of biological activities, including immune signaling, inflammation, and brain development and function. Two desaturase steps (Δ6, encoded by FADS2 and Δ5, encoded by FADS1 are rate limiting in the conversion of dietary essential 18 carbon PUFAs (18C-PUFAs such as LA (18:2, n-6 to AA and α-linolenic acid (ALA, 18:3, n-3 to EPA and DHA. GWAS and candidate gene studies have consistently identified genetic variants within FADS1 and FADS2 as determinants of desaturase efficiencies and levels of LcPUFAs in circulating, cellular and breast milk lipids. Importantly, these same variants are documented determinants of important cardiovascular disease risk factors (total, LDL, and HDL cholesterol, triglycerides, CRP and proinflammatory eicosanoids. FADS1 and FADS2 lie head-to-head (5' to 5' in a cluster configuration on chromosome 11 (11q12.2. There is considerable linkage disequilibrium (LD in this region, where multiple SNPs display association with LcPUFA levels. For instance, rs174537, located ∼ 15 kb downstream of FADS1, is associated with both FADS1 desaturase activity and with circulating AA levels (p-value for AA levels = 5.95 × 10(-46 in humans. To determine if DNA methylation variation impacts FADS activities, we performed genome-wide allele-specific methylation (ASM with rs174537 in 144 human liver samples. This approach identified highly significant ASM with CpG sites between FADS1 and FADS2 in a putative enhancer signature region, leading to the hypothesis that the phenotypic associations of rs174537 are likely due to methylation differences. In support of this hypothesis, methylation levels of the most significant probe were strongly associated with FADS1 and, to a lesser degree, FADS2 activities.

  11. Effects of piperonyl butoxide on the toxicity of the organophosphate temephos and the role of esterases in the insecticide resistance of Aedes aegypti

    Directory of Open Access Journals (Sweden)

    Boscolli Barbosa Pereira

    2014-10-01

    Full Text Available Introduction The effects of piperonyl butoxide (PBO on the toxicity of the organophosphate temephos (TE and the role of esterases in the resistance of Aedes aegypti to this insecticide were evaluated. Methods A. aegypti L4 larvae susceptible and resistant to TE were pre-treated with PBO solutions in acetone at concentrations of 0.125, 0.25, 0.5, 1, and 2% for 24h and subsequently exposed to a diagnostic concentration of 0.02mg/L aqueous TE solution. The esterase activity of the larvae extracts pre-treated with varying PBO concentrations and exposed to TE for three time periods was determined. Results At concentrations of 0.25, 0.5, 1, and 2%, PBO showed a significant synergistic effect with TE toxicity. High levels of esterase activity were associated with the survival of A. aegypti L4 larvae exposed to TE only. Conclusions The results of the biochemical assays suggest that PBO has a significant inhibitory effect on the total esterase activity in A. aegypti larvae.

  12. Methylation associated inactivation of RASSF1A and its synergistic effect with activated K-Ras in nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Yu Jing

    2009-12-01

    Full Text Available Abstract Background Epigenetic silencing of tumor suppressor genes associated with promoter methylation is considered to be a hallmark of oncogenesis. RASSF1A is a candidate tumor suppressor gene which was found to be inactivated in many human cancers. Although we have had a prelimilary cognition about the function of RASSF1A, the exact mechanisms about how RASSF1A functions in human cancers were largely unknown. Moreover, the effect of mutated K-Ras gene on the function of RASSF1A is lacking. The aim of this study was to investigate the expression profile and methylation status of RASSF1A gene, and to explore its concrete mechanisms as a tumor suppressor gene in Nasopharyngeal Carcinoma. Methods We examined the expression profile and methylation status of RASSF1A in two NPC cell lines, 38 primary nasopharyngeal carcinoma and 14 normal nasopharyngeal epithelia using RT-PCR and methylated specific PCR(MSP respectively. 5-aza-dC was then added to confirm the correlation between hypermethylation status and inactivation of RASSF1A. The NPC cell line CNE-2 was transfected with exogenous pcDNA3.1(+/RASSF1A plasmid in the presence or absence of mutated K-Ras by liposome-mediated gene transfer method. Flow cytometry was used to examine the effect of RASSF1A on cell cycle modulation and apoptosis. Meanwhile, trypan blue dye exclusion assays was used to detect the effect of RASSF1A transfection alone and the co-transfection of RASSF1A and K-Ras on cell proliferation. Results Promoter methylation of RASSF1A could be detected in 71.05% (27/38 of NPC samples, but not in normal nasopharyngeal epithelia. RASSF1A expression in NPC primary tumors was lower than that in normal nasopharyngeal epithelial (p p p p Conclusion Expression of RASSF1A is down-regulated in NPC due to the hypermethylation of promoter. Exogenous expression of RASSF1A is able to induce growth inhibition effect and apoptosis in tumor cell lines, and this effect could be enhanced by activated

  13. Analysis of esterase isozyme and SSR for mutagenic progenies induced by space mutation in mustard

    International Nuclear Information System (INIS)

    Shen Jinjuan; Liu Yihua; Zhang Zhaorong; Ran Guangkui; Zhao Shouzhong; Xiao Li

    2012-01-01

    Seeds of five mustard (Brassica juncea Coss) varieties were carried into outer space by 'Shijian No.8' satellite. After five years' consecutive planting and selection, ten relatively stable mutant lines were obtained, which had significant variation in agronomic and economic characters. The mutant lines and their original varieties without space mutation treatment as control were studied by esterase isozyme and SSR analyses. Electrophoresis analysis of esterase isozymes indicated that there were differences between mutant lines and their controls in enzyme types and enzyme activity. Different mustard varieties had different enzymographs, and so did the mutants induced by space mutation, which shows different sensitivity among different mustard varieties. The SSR analysis showed that large differences were found in the SSR loci between mutant lines and their original variety, the variation frequency was between 9.52% and 57.14% with an average frequency of 26.19% for all the mutant lines. Among the mutant SSR loci, about 56.36% showed changes in band number and 43.64% in molecular weight. These results indicated that the ten mutant lines had large genetic difference in phenotype, genomic sequence and gene expression, and the outer space mutation would be an effective method to develop new mustard germplasm and variety. (authors)

  14. Est16, a New Esterase Isolated from a Metagenomic Library of a Microbial Consortium Specializing in Diesel Oil Degradation.

    Science.gov (United States)

    Pereira, Mariana Rangel; Mercaldi, Gustavo Fernando; Maester, Thaís Carvalho; Balan, Andrea; Lemos, Eliana Gertrudes de Macedo

    2015-01-01

    Lipolytic enzymes have attracted attention from a global market because they show enormous biotechnological potential for applications such as detergent production, leather processing, cosmetics production, and use in perfumes and biodiesel. Due to the intense demand for biocatalysts, a metagenomic approach provides methods of identifying new enzymes. In this study, an esterase designated as Est16 was selected from 4224 clones of a fosmid metagenomic library, revealing an 87% amino acid identity with an esterase/lipase (accession number ADM63076.1) from an uncultured bacterium. Phylogenetic studies showed that the enzyme belongs to family V of bacterial lipolytic enzymes and has sequence and structural similarities with an aryl-esterase from Pseudomonas fluorescens and a patented Anti-Kazlauskas lipase (patent number US20050153404). The protein was expressed and purified as a highly soluble, thermally stable enzyme that showed a preference for basic pH. Est16 exhibited activity toward a wide range of substrates and the highest catalytic efficiency against p-nitrophenyl butyrate and p-nitrophenyl valerate. Est16 also showed tolerance to the presence of organic solvents, detergents and metals. Based on molecular modeling, we showed that the large alpha-beta domain is conserved in the patented enzymes but not the substrate pocket. Here, it was demonstrated that a metagenomic approach is suitable for discovering the lipolytic enzyme diversity and that Est16 has the biotechnological potential for use in industrial processes.

  15. Est16, a New Esterase Isolated from a Metagenomic Library of a Microbial Consortium Specializing in Diesel Oil Degradation.

    Directory of Open Access Journals (Sweden)

    Mariana Rangel Pereira

    Full Text Available Lipolytic enzymes have attracted attention from a global market because they show enormous biotechnological potential for applications such as detergent production, leather processing, cosmetics production, and use in perfumes and biodiesel. Due to the intense demand for biocatalysts, a metagenomic approach provides methods of identifying new enzymes. In this study, an esterase designated as Est16 was selected from 4224 clones of a fosmid metagenomic library, revealing an 87% amino acid identity with an esterase/lipase (accession number ADM63076.1 from an uncultured bacterium. Phylogenetic studies showed that the enzyme belongs to family V of bacterial lipolytic enzymes and has sequence and structural similarities with an aryl-esterase from Pseudomonas fluorescens and a patented Anti-Kazlauskas lipase (patent number US20050153404. The protein was expressed and purified as a highly soluble, thermally stable enzyme that showed a preference for basic pH. Est16 exhibited activity toward a wide range of substrates and the highest catalytic efficiency against p-nitrophenyl butyrate and p-nitrophenyl valerate. Est16 also showed tolerance to the presence of organic solvents, detergents and metals. Based on molecular modeling, we showed that the large alpha-beta domain is conserved in the patented enzymes but not the substrate pocket. Here, it was demonstrated that a metagenomic approach is suitable for discovering the lipolytic enzyme diversity and that Est16 has the biotechnological potential for use in industrial processes.

  16. Mining pathway associations for disease-related pathway activity analysis based on gene expression and methylation data.

    Science.gov (United States)

    Lee, Hyeonjeong; Shin, Miyoung

    2017-01-01

    The problem of discovering genetic markers as disease signatures is of great significance for the successful diagnosis, treatment, and prognosis of complex diseases. Even if many earlier studies worked on identifying disease markers from a variety of biological resources, they mostly focused on the markers of genes or gene-sets (i.e., pathways). However, these markers may not be enough to explain biological interactions between genetic variables that are related to diseases. Thus, in this study, our aim is to investigate distinctive associations among active pathways (i.e., pathway-sets) shown each in case and control samples which can be observed from gene expression and/or methylation data. The pathway-sets are obtained by identifying a set of associated pathways that are often active together over a significant number of class samples. For this purpose, gene expression or methylation profiles are first analyzed to identify significant (active) pathways via gene-set enrichment analysis. Then, regarding these active pathways, an association rule mining approach is applied to examine interesting pathway-sets in each class of samples (case or control). By doing so, the sets of associated pathways often working together in activity profiles are finally chosen as our distinctive signature of each class. The identified pathway-sets are aggregated into a pathway activity network (PAN), which facilitates the visualization of differential pathway associations between case and control samples. From our experiments with two publicly available datasets, we could find interesting PAN structures as the distinctive signatures of breast cancer and uterine leiomyoma cancer, respectively. Our pathway-set markers were shown to be superior or very comparable to other genetic markers (such as genes or gene-sets) in disease classification. Furthermore, the PAN structure, which can be constructed from the identified markers of pathway-sets, could provide deeper insights into

  17. Fibrillarin methylates H2A in RNA polymerase I trans-active promoters in Brassica oleracea

    Czech Academy of Sciences Publication Activity Database

    Loza-Muller, L.; Rodriguez-Corona, U.; Sobol, Margaryta; Rodriguez-Zapata, L.C.; Hozák, Pavel; Castano, E.

    2015-01-01

    Roč. 6, Nov 6 (2015) ISSN 1664-462X R&D Projects: GA ČR GAP305/11/2232; GA ČR GA15-08738S; GA MPO FR-TI3/588; GA TA ČR(CZ) TE01020118; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : histones * methylation * RNA polymerase I * Brassica * phosphoinositide Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.495, year: 2015

  18. Synthesis and Herbicidal Activities of Novel 4-(4-(5-methyl-3-arylisoxazol-4-ylthiazol-2-ylpiperidyl Carboxamides and Thiocarboxamides

    Directory of Open Access Journals (Sweden)

    Ai-Dong Zhang

    2009-03-01

    Full Text Available A series of novel 4-(4-(5-methyl-3-arylisoxazol-4-ylthiazol-2-ylpiperidyl carboxamides and thiocarboxamides were synthesized as potential lead compounds of inhibitors targeting D1 protease in plants. These compounds were designed on the basis of a D1 protease inhibitor hit structure identified by homology modeling and virtual screening. The syntheses of these compounds were accomplished via a four-step procedure including the isoxazole ring formation, a-bromination of acetyl group, thiazole ring formation, and carboxamide/thiocarboxamide attachment. The in vivo herbicidal activity tests show that most compounds possess moderate to good herbicidal activities. The enzyme activity of one compound against the native spinach D1 protease exhibits a competitive inhibition. The results suggest that these compounds are indeed potential inhibitors for targeting D1 protease in plants.

  19. The Lp_3561 and Lp_3562 enzymes support a functional divergence process in the lipase/esterase toolkit from Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Maria Esteban-Torres

    2016-07-01

    Full Text Available Lactobacillus plantarum species is a good source of esterases since both lipolytic and esterase activities have been described for strains of this species. No fundamental biochemical difference exists among esterases and lipases since both share a common catalytic mechanism. L. plantarum WCFS1 possesses a protein, Lp_3561, which is 44% identical to a previously described lipase, Lp_3562. In contrast to Lp_3562, Lp_3561 was unable to degrade esters possessing a chain length higher than C4 and the triglyceride tributyrin. As in other L. plantarum esterases, the electrostatic potential surface around the active site in Lp_3561 is predicted to be basic, whereas it is essentially neutral in the Lp_3562 lipase. The fact that the genes encoding both proteins were located contiguously in the L. plantarum WCFS1 genome, suggests that they originated by tandem duplication, and therefore are paralogs as new functions have arisen during evolution. The presence of the contiguous lp_3561 and lp_3562 genes was studied among L. plantarum strains. They are located in a 8,903 bp DNA fragment that encodes proteins involved in the catabolism of sialic acid and are predicted to increase bacterial adaptability under certain growth conditions.

  20. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  1. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  2. Arsenic activates the expression of 3β-HSD in mouse Leydig cells through repression of histone H3K9 methylation

    DEFF Research Database (Denmark)

    Alamdar, Ambreen; Xi, Guochen; Huang, Qingyu

    2017-01-01

    methylation. The results showed that H3K9me2/3 demethylase (JMJD2A) inhibitor, quercetin (Que) significantly attenuated the decrease of H3K9me2/3 and increase of 3β-HSD expression induced by arsenic. To further elucidate the mechanism for the activation of 3β-HSD, we determined the histone H3K9 methylation......Arsenic exposure has been associated with male reproductive dysfunction by disrupting steroidogenesis; however, the roles of epigenetic drivers, especially histone methylation in arsenic-induced steroidogenic toxicity remain not well documented. In this study, we investigated the role of histone H3...... lysine 9 (H3K9) methylation in steroidogenesis disturbance in mouse Leydig cells (MLTC-1) due to arsenic exposure. Our results indicated that mRNA and protein expression levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) were both significantly up-regulated while the rest of key genes involved...

  3. Larvicidal activity of oils, fatty acids, and methyl esters from ripe and unripe fruit of Solanum lycocarpum (Solanaceae against the vector Culex quinquefasciatus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Viviane de Cássia Bicalho Silva

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION:The larvicidal activity of oils, fatty acids, and methyl esters of Solanum lycocarpum fruit against Culex quinquefasciatus is unknown.METHODS:The larvicidal activity of samples of ripe and unripe fruit from S. lycocarpum was evaluated against third and fourth instar larvae of C. quinquefasciatus .RESULTS:The oils, fatty acids, and methyl esters of S. lycocarpum showed the greatest larvicidal effect (57.1-95.0% at a concentration of 100mg/L (LC 50values between 0.70 and 27.54mg/L.CONCLUSIONS:Solanum lycocarpum fruit may be a good source of new natural products with larvicidal activity.

  4. Body size, physical activity and risk of colorectal cancer with or without the CpG island methylator phenotype (CIMP.

    Directory of Open Access Journals (Sweden)

    Laura A E Hughes

    Full Text Available BACKGROUND: We investigated how body size and physical activity influence the risk of the CpG island methylator phenotype (CIMP in colorectal cancer (CRC. METHODS: In the Netherlands Cohort Study (n = 120,852, risk factors were self-reported at baseline in 1986. After 7.3 years of follow-up, 603 cases and 4,631 sub-cohort members were available. CIMP status according to the Weisenberger markers was determined using methylation specific PCR on DNA from paraffin embedded tumor tissue. Hazard rate ratios (HR and 95% confidence intervals for CIMP (27.7% and non-CIMP (72.3% tumors were calculated according to BMI, BMI at age 20, BMI change, trouser/skirt size, height, and physical activity. RESULTS: BMI modeled per 5 kg/m(2 increase was associated with both CIMP and non-CIMP tumors, however, HRs were attenuated when additionally adjusted for trouser/skirt size. Trouser/skirt size, per 2 size increase, was associated with both tumor subtypes, even after adjustment for BMI (CIMP HR: 1.20, 95%CI: 1.01-1.43; non-CIMP HR: 1.14, 95%CI: 1.04-1.28. Height per 5 cm was associated with both tumor sub-types, but HRs were attenuated when adjusted for body weight. BMI at age 20 was positively associated with increased risk of CIMP tumors and the association was significantly less pronounced for non-CIMP tumors (P-heterogeneity = 0.01. Physical activity was inversely associated with both subtypes, but a dose-response association was observed only for non-CIMP tumors (P-trend = 0.02. CONCLUSIONS: Body size, especially central adiposity, may increase the risk of both CIMP and non-CIMP tumors. Body fat at young age may differentially influence risk. Physical activity appears to decrease the risk of CRC regardless of these molecular subtypes.

  5. Body size, physical activity and risk of colorectal cancer with or without the CpG island methylator phenotype (CIMP).

    Science.gov (United States)

    Hughes, Laura A E; Simons, Colinda C J M; van den Brandt, Piet A; Goldbohm, R Alexandra; de Goeij, Anton F; de Bruïne, Adriaan P; van Engeland, Manon; Weijenberg, Matty P

    2011-04-05

    We investigated how body size and physical activity influence the risk of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC). In the Netherlands Cohort Study (n = 120,852), risk factors were self-reported at baseline in 1986. After 7.3 years of follow-up, 603 cases and 4,631 sub-cohort members were available. CIMP status according to the Weisenberger markers was determined using methylation specific PCR on DNA from paraffin embedded tumor tissue. Hazard rate ratios (HR) and 95% confidence intervals for CIMP (27.7%) and non-CIMP (72.3%) tumors were calculated according to BMI, BMI at age 20, BMI change, trouser/skirt size, height, and physical activity. BMI modeled per 5 kg/m(2) increase was associated with both CIMP and non-CIMP tumors, however, HRs were attenuated when additionally adjusted for trouser/skirt size. Trouser/skirt size, per 2 size increase, was associated with both tumor subtypes, even after adjustment for BMI (CIMP HR: 1.20, 95%CI: 1.01-1.43; non-CIMP HR: 1.14, 95%CI: 1.04-1.28). Height per 5 cm was associated with both tumor sub-types, but HRs were attenuated when adjusted for body weight. BMI at age 20 was positively associated with increased risk of CIMP tumors and the association was significantly less pronounced for non-CIMP tumors (P-heterogeneity = 0.01). Physical activity was inversely associated with both subtypes, but a dose-response association was observed only for non-CIMP tumors (P-trend = 0.02). Body size, especially central adiposity, may increase the risk of both CIMP and non-CIMP tumors. Body fat at young age may differentially influence risk. Physical activity appears to decrease the risk of CRC regardless of these molecular subtypes.

  6. L1 retrotransposition is activated by Ten-eleven-translocation protein 1 and repressed by methyl-CpG binding proteins.

    Science.gov (United States)

    Zhang, Peng; Ludwig, Anne K; Hastert, Florian D; Rausch, Cathia; Lehmkuhl, Anne; Hellmann, Ines; Smets, Martha; Leonhardt, Heinrich; Cardoso, M Cristina

    2017-09-03

    One of the major functions of DNA methylation is the repression of transposable elements, such as the long-interspersed nuclear element 1 (L1). The underlying mechanism(s), however, are unclear. Here, we addressed how retrotransposon activation and mobilization are regulated by methyl-cytosine modifying ten-eleven-translocation (Tet) proteins and how this is modulated by methyl-CpG binding domain (MBD) proteins. We show that Tet1 activates both, endogenous and engineered L1 retrotransposons. Furthermore, we found that Mecp2 and Mbd2 repress Tet1-mediated activation of L1 by preventing 5hmC formation at the L1 promoter. Finally, we demonstrate that the methyl-CpG binding domain, as well as the adjacent non-sequence specific DNA binding domain of Mecp2 are each sufficient to mediate repression of Tet1-induced L1 mobilization. Our study reveals a mechanism how L1 elements get activated in the absence of Mecp2 and suggests that Tet1 may contribute to Mecp2/Mbd2-deficiency phenotypes, such as the Rett syndrome. We propose that the balance between methylation "reader" and "eraser/writer" controls L1 retrotransposition.

  7. Urinary retinoic acid receptor-β2 gene promoter methylation and hyaluronidase activity as noninvasive tests for diagnosis of bladder cancer.

    Science.gov (United States)

    Eissa, Sanaa; Zohny, Samir F; Shehata, Hanan Hussien; Hegazy, Marwa G A; Salem, Ahmed M; Esmat, Mohamed

    2012-04-01

    We evaluated the significance of urinary retinoic acid receptor-β2 (RAR-β2) gene promoter methylation and hyaluronidase activity in comparison with voided urine cytology (VUC) in diagnosis of bladder cancer. This study included 100 patients diagnosed with bladder cancer, 65 patients with benign urological disorders and 51 healthy volunteers. Urine supernatant was used for determining hyaluronidase activity by zymography while urine sediment was used for cytology and detection of methylated RAR-β2 gene promoter by methylation specific nested PCR. The sensitivity and specificity were 53% and 90.5% for VUC, 65% and 89.7% for percent methylation fraction of RAR-β2 gene promoter, and 89% and 90.5% for hyaluronidase activity; combination of the three parameters increased sensitivity to 95%. A significant association was observed between investigated markers and advanced grade tumor. Combined use of RAR-β2 gene promoter methylation, hyaluronidase activity and VUC is promising non-invasive tool for bladder cancer detection. Copyright © 2012. Published by Elsevier Inc.

  8. Extracellular esterases of phylloplane yeast Pseudozyma antarctica induce defect on cuticle layer structure and water-holding ability of plant leaves.

    Science.gov (United States)

    Ueda, Hirokazu; Mitsuhara, Ichiro; Tabata, Jun; Kugimiya, Soichi; Watanabe, Takashi; Suzuki, Ken; Yoshida, Shigenobu; Kitamoto, Hiroko

    2015-08-01

    Aerial plant surface (phylloplane) is a primary key habitat for many microorganisms but is generally recognized as limited in nutrient resources. Pseudozyma antarctica, a nonpathogenic yeast, is commonly isolated from plant surfaces and characterized as an esterase producer with fatty acid assimilation ability. In order to elucidate the biological functions of these esterases, culture filtrate with high esterase activity (crude enzyme) of P. antarctica was applied onto leaves of tomato and Arabidopsis. These leaves showed a wilty phenotype, which is typically associated with water deficiency. Furthermore, we confirmed that crude enzyme-treated detached leaves clearly lost their water-holding ability. In treated leaves of both plants, genes associated to abscisic acid (ABA; a plant stress hormone responding osmotic stress) were activated and accumulation of ABA was confirmed in tomato plants. Microscopic observation of treated leaf surfaces revealed that cuticle layer covering the aerial epidermis of leaves became thinner. A gas chromatography-mass spectrometry (GC-MS) analysis exhibited that fatty acids with 16 and 18 carbon chains were released in larger amounts from treated leaf surfaces, indicating that the crude enzyme has ability to degrade lipid components of cuticle layer. Among the three esterases detected in the crude enzyme, lipase A, lipase B, and P. antarctica esterase (PaE), an in vitro enzyme assay using para-nitrophenyl palmitate as substrate demonstrated that PaE was the most responsible for the degradation. These results suggest that PaE has a potential role in the extraction of fatty acids from plant surfaces, making them available for the growth of phylloplane yeasts.

  9. The monotony of transferrin and esterase electrophoretic patterns in pirarucu, Arapaima gigas (Schinz, 1822) from Santa Cruz Lake, Tefé River, Amazonas, Brazil.

    Science.gov (United States)

    Teixeira, A S

    2008-05-07

    Starch gel electrophoresis was used for examining the transferrin gene locus (Tf) and two esterase gene loci (Est-1 and Est-D1) of a pirarucu (Arapaima gigas) population sample collected from Santa Cruz Lake, Tefé River, Amazonas, Brazil. The Tf locus was tentatively classified as being polymorphic, showing two double-banded patterns (Tf(12) and Tf(22)) of the three theoretically expected ones (Tf(11), Tf(12) and Tf(22)), presumably controlled by two co-dominant alleles, Tf(1) and Tf(2). The monotony detected in pirarucu Tf locus genotypes showing a very high proportion of the double-banded heterozygote pattern Tf(12) (95% of the sampled individuals) may indicate the possibility of their having come from representatives of the same brood begotten by a pair of fish, where a single-banded Tf(11) homozygote pattern male would have crossed with a single-banded Tf(22) homozygote pattern female, or vice versa. One zone of electrophoretic activity was detected in esterase, presumably controlled by a monomorphic Est-1 locus with the fixed allele Est-1(1) where all individuals showed the single-banded Est-1(11) homozygote pattern. Esterase-D also displayed one zone of electrophoretic activity, presumably controlled by a monomorphic Est-D1 locus with a fixed allele Est-D1(1) where all individuals revealed the single-banded Est-D1(11) genotype pattern. The monotony comprised by single-banded genotype patterns in both esterase systems tested may also indicate the possibility of the individuals from the sample examined having come from representatives of the same brood begotten by a pair of fish with both the male and female having the same genotypes.

  10. Methylation of 6-mercaptopurine and 6-thioguanine by thiopurine S-methyltransferase. A comparison of activity in red blood cell samples of 199 blood donors.

    Science.gov (United States)

    Kröplin, T; Iven, H

    2000-07-01

    To compare 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG) as substrates for the methylation reaction catalysed by the enzyme thiopurine S-methyltransferase (TPMT). TPMT activity in haemolysed red blood cells of healthy blood donors was determined twice, using the same experimental setting and equal molar concentrations of 6-TG and 6-MP as substrates. After extraction, the reaction products 6-methyl-TG and 6-methyl-MP were quantified using specific high-performance liquid chromatography procedures. The medians of the TPMT activities from 199 blood donors were 54.4 nmol 6-MTG g(-1)Hb h(-1) when measured with 6-TG as the substrate and 35.8 nmol 6-MMP g(-1) Hb h(-1) when measured with 6-MP. The correlation coefficient for the 199 pairs of values was 0.8695. On average, TPMT activity was 34% lower with 6-MP as substrate than with 6-TG as substrate.

  11. Esterases of laboratory-reared and field-collected cotton boll weevils, Anthonomus grandis Boh.: polymorphism of adult esterases and formal genetics of esterase II.

    Science.gov (United States)

    Biggers, C J; Bancroft, H R

    1977-04-01

    The esterases of the cotton boll weevil were separated by polyacrylamide gel electrophoresis into four major regions. These were named Est I-IV in order of migration from anode to origin. Polymorphism was observed in all regions. The Est II region was shown to consist of no more than two bands (fast and slow). The inheritance of the fast and slow bands of Est II was demonstrated to be controlled by codominant autosomal alleles. Analysis of the gene frequency of the Est II region showed that one field population was consistent with the Hardy-Weinberg law (P = 0.995), while a second field population was not at equilibrium (P less than 0.001).

  12. Esterases in striated muscle from mice with the Chediak-Higashi syndrome

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1981-01-01

    In this paper a localized strong reaction for non-specific esterase forming cylindric structures is described within skeletal muscle fibres from the beige mouse. It seems from zymograms and protein electrophoresis that this esterase is membrane bound, highly reactive and present in rather small...

  13. Esterase Isoenzyme Profiles in Acute and Chronic Leukemias.

    Science.gov (United States)

    Drexler, H G; Gignac, S M; Hoffbrand, A V; Minowada, J

    1991-01-01

    Using isoelectric focusing (IEF) a number of carboxylic esterase isoenzymes (EC 3.1.1.1) with isoelectric points between pH 4.5-8.0 can be separated. One particular isoenzyme with an isoelectric point at about pH 6.0, the Mono-band, can be selectively and completely inhibited by sodium fluoride; this isoenzyme comprises a number of closely related subcomponents and may appear in more than one band on the gel. We analyzed the expression of typical esterase isoenzyme patterns in cells from a large panel of leukemias which were tested under identical conditions by IEF on horizontal thin-layer polyacrylamide gels with an ampholyte of pH 2-11. The 442 cases of acute and chronic myeloid and lymphoid leukemia (AML/AMMoL, CML/CMML, ALL, CLL) were classified according to clinical, morpho-cytochemical and immunophenotyping criteria. While bands between pH 4.5-5.5 appeared not to be specific for lineage or stage of differentiation, isoenzymes between pH 6.6-7.7 provided information on the type of leukemia involved. Seven typical isoenzyme patterns termed Mono1/Mono2 (fo monocyte-associated), My1/My2 (myeloid), Lym1/Lym2 (lymphoid) and Und (undifferentiated) could be discerned. Lym and Und patterns are characterized by fewer bands with a weaker staining intensity than Mono and My patterns. Nearly all cases of lymphoid leukemias (acute and chronic) expressed only Lym or Und esterase isoenzyme patterns, but no Mono or My patterns. Cases of acute or chronic myeloid and (myelo)monocytic leukemia showed strong isoenzyme staining displaying predominantly Mono or My isoenzyme patterns. The isoenzyme patterns found in CML in lymphoid or myeloid blast crisis corresponded to those seen in the respective acute leukemias, ALL or AML. The Mono-band was found in most cases of leukemias with monocytic elements (AMMoL 80%, CML 44%, CMML 100%), in the occasional case of CML-myeloid blast crisis or AML, but in none of the cases of ALL or CLL. This isoenzyme is a distinctive, specific marker for

  14. Photo Degradation of Methyl Orange by Persulfate Activated with Zero Valent Iron

    Science.gov (United States)

    Munkoeva, V. A.; Sizykh, M. R.; Batoeva, A. A.

    2017-11-01

    The oxidative degradation of Methyl Orange (MO) subjected to direct photolysis (Solar) and various oxidative systems was studied. The comparative experiments have shown that MO conversion and mineralization increases in the following order: Solar ∼ Solar/Fe0 ∼ Solar/S2O82- influence of the main factors (duration of exposure, the ratio of initial concentrations of MO:S2O82-:Fe0, pH and temperature of the reaction medium) on the degree of MO conversion and mineralization was studied. The optimal pH and temperature of the reaction medium were 5.8 and 25°C, respectively. The rate of MO decomposition and mineralization increased proportionally to the initial concentration of the oxidant at the molar ratios [S2O82-] :[MO] ≤ 12. Judging by the nature of the kinetic curves, a further increase of this ratio is impractical. However, an increase in the oxidant concentration had a positive effect on the degrees of conversion and mineralization of total organic carbon (TOC). Thus, at the ratios of 12:1 and 48:1, the conversion efficiency of TOC was 23 and 60 %, respectively. The optimal concentration of Fe0 was 100 mg/l.

  15. Synthesis and photocatalytic activity of anatase TiO2 nanoparticles for degradation of methyl orange

    Science.gov (United States)

    Singh, Manmeet; Duklan, Neha; Singh, Pritpal; Sharma, Jeewan

    2018-05-01

    In present study, TiO2 nanoparticles, in anatase form, were successfully synthesized using TiCl4 as precursor. These nanoparticles were synthesized by sol-gel method at room temperature (298 K). As prepared samples were characterized for phase structure, optical absorption and surface properties using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy and UV-Visible spectroscopy. The synthesized TiO2 nanoparticles sample was compared with one of the most efficient commercial photocatalyst Degussa TiO2 also known as P(25). The effect of phase composition of anatase TiO2 nanoparticles, as compared to P(25), on photocatalytic decomposition of organic dye, methyl orange (MO) was studies under UV light illumination. An enhanced degradation of hazardous dye was observed in the presence of anatase TiO2 nanoparticles as compared to P(25) due to slow recombination rate. Other possible reasons for this enhancement have also been discussed.

  16. Simultaneous determination of carboprost methylate and its active metabolite carboprost in dog plasma by liquid chromatography-tandem mass spectrometry with positive/negative ion-switching electrospray ionization and its application to a pharmacokinetic study.

    Science.gov (United States)

    Yin, Lei; Meng, Xiangjun; Zhou, Xiaotong; Zhang, Tinglan; Sun, Heping; Yang, Zhichao; Yang, Bo; Xiao, Ning; Fawcett, J Paul; Yang, Yan; Gu, Jingkai

    2015-08-15

    A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method using positive/negative electrospray ionization (ESI) switching for the simultaneous quantitation of carboprost methylate and carboprost in dog plasma has been developed and validated. After screening, the esterase inhibitor, dichlorvos was added to the whole blood at a ratio of 1:99 (v/v) to stabilize carboprost methylate during blood collection, sample storage and LLE. Indomethacin was added to plasma to inhibit prostaglandins synthesis after sampling. After liquid-liquid extraction of 500μL plasma with ethyl ether-dichloromethane (75:25, v/v), analytes and internal standard (IS), alprostadil-d4, were chromatographed on a CAPCELL PAK Phenyl column (150×2.0mm, 5μm) using acetonitrile-5mM ammonium acetate as mobile phase. Carboprost methylate was detected by positive ion electrospray ionization followed by multiple reaction monitoring (MRM) of the transition at m/z 400.5→329.3; the carboprost and IS were detected by negative ion electrospray ionization followed by MRM of the transitions at m/z 367.2→323.2, and 357.1→321.2, respectively. The method was linear for both analytes in the concentration range 0.05-30ng/mL with intra- and inter-day precisions (as relative standard deviation) of ≤6.75% and accuracy (as relative error) of ≤7.21% and limit of detection (LOD) values were 10 and 20pg/mL, respectively. The method was successfully applied to a pharmacokinetic study of the analytes in beagle dogs after intravaginal administration of a suppository containing 0.5mg carboprost methylate. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Feruloyl esterase from Aspergillus clavatus improves xylan hydrolysis of sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Dyoni M. de Oliveira

    2016-12-01

    Full Text Available Feruloyl esterase is a subclass of carboxylic acid esterases with the capacity to release ferulic acid and other cinnamic acids from plant cell walls and synthetic substrates. Feruloyl esterases act synergistically with xylanases removing ferulic acid residues esterified to arabinoxylans. Feruloyl esterase type D from Aspergillus clavatus (AcFAE was expressed in Escherichia coli, purified, and applied with a commercial xylanase consortium (Novozymes for hydrolysis of sugarcane bagasse. Feruloyl esterase plus xylanase increased 5.13-fold the releasing of ferulic acid from sugarcane bagasse. Removal of only 7.7% of ferulic acid content by AcFAE increased 97.3% the sugarcane bagasse hydrolysis by xylanase. These data support the use of AcFAE as an interesting adjuvant enzyme to improve lignocellulose digestion and biotechnological tool for biorefineries.

  18. Organophosphate acetylcholine esterase inhibitor poisoning from a home-made shampoo.

    Science.gov (United States)

    Sadaka, Yair; Broides, Arnon; Tzion, Raffi Lev; Lifshitz, Matitiahu

    2011-07-01

    Organophosphate acetylcholine esterase inhibitor poisoning is a major health problem in children. We report an unusual cause of organophosphate acetylcholine esterase inhibitor poisoning. Two children were admitted to the pediatric intensive care unit due to organophosphate acetylcholine esterase inhibitor poisoning after exposure from a home-made shampoo that was used for the treatment of head lice. Owing to no obvious source of poisoning, the diagnosis of organophosphate acetylcholine esterase inhibitor poisoning in one of these patients was delayed. Both patients had an uneventful recovery. Organophosphate acetylcholine esterase inhibitor poisoning from home-made shampoo is possible. In cases where the mode of poisoning is unclear, direct questioning about the use of home-made shampoo is warranted, in these cases the skin and particularly the scalp should be rinsed thoroughly as soon as possible.

  19. Synthesis, Characterization and Antimicrobial Activities of Transition Metal Complexes of methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate

    International Nuclear Information System (INIS)

    Ikram, M.; Rehman, S.

    2016-01-01

    New metal complexes with Schiff base ligand methyl 2-(((E)-(2-hydroxyphenyl)methylidene)amino)benzoate, were synthesized and characterized. Elemental analyses, EI-MS, 1H and 13C(1H)-NMR were used for ligand characterization whereas elemental analyses, EI-MS, IR and UV-Visible spectroscopic techniques were used for the transition metal compounds. All these analyses reveal the bis arrangement of the ligand around the metal centres. The compounds were studied for their antimicrobial activities against different pathogenic microbial species. It was found that the Schiff base ligand was completely inactive in comparison to the transition metal compounds. It was also observed that nickel based metal complex shown good results against Candida albican (25 mm) and zinc based metal complex against Agrobacterium tumefaciens (16 mm). (author)

  20. Plasmon-resonance-enhanced visible-light photocatalytic activity of Ag quantum dots/TiO2 microspheres for methyl orange degradation

    Science.gov (United States)

    Yu, Xin; Shang, Liwei; Wang, Dongjun; An, Li; Li, Zhonghua; Liu, Jiawen; Shen, Jun

    2018-06-01

    We successfully prepared Ag quantum dots modified TiO2 microspheres by facile solvothermal and calcination method. The as-prepared Ag quantum dots/TiO2 microspheres were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The Ag quantum dots/TiO2 photocatalyst showed excellent visible light absorption and efficient photocatalytic activity for methyl orange degradation. And the sample with the molar ratio of 0.05 (Ag to Ti) showed the best visible light photocatalytic activity for methyl orange degradation, mainly because of the surface plasmon resonance (SPR) effects of Ag quantum dots to generate electron and hole pairs for enhanced visible light photocatalysis. Finally, possible visible light photocatalytic mechanism of Ag quantum dots/TiO2 microspheres for methyl orange degradation was proposed in detail.

  1. N-acetyltransferase-dependent activation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine: formation of 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo [4,5-b]pyridine, a possible biomarker for the reactive dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lauritz; Alexander, J.

    2000-01-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. PhIP is metabolically activated to the ultimate mutagenic metabolite by CYP P450-mediated N-hydroxylation followed by phase II esterification, Incubation of N...

  2. Preparation of ErMnO3 by Sol-gel Method and its Photocatalytic Activity for Removal of Methyl Orange from Water

    Science.gov (United States)

    Xie, X. Y.; Yang, J. N.; Yu, L. L.; Min, J. Y.; Sun, D. D.; Tang, P. S.; Chen, H. F.

    2018-05-01

    The single phase perovskite ErMnO3 was synthesized using Er(NO3)3, manganese acetate, citric acid and urea by a facile sol-gel method. The gel of ErMnO3 precursor was kept for 36 hours in 100 °C oven to get the xerogel. Then, the xerogel was calcined at 800 °C for 12 hours in muffle furnace to prepare single phase ErMnO3. The prepared sample was characterized by thermogravimetry differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Under ultraviolet light, the photocatalytic activity of ErMnO3 was studied with methyl orange of 20 mg/L as the simulated sewage. The results show that the ErMnO3 sample particle size distribution is relatively uniform, the average grain size is mainly around 100 nm. The photocatalytic experiment demonstrates that ErMnO3 is highly photocatalytic activity for removal of methyl orange from water. When methyl orange of 20 mg/L is degraded for 120 min in the presence of ErMnO3, the degradation rate of methyl orange can reach about 95%. The degradation of methyl orange accords with first order kinetic model in presence ErMnO3 sample, and the apparent rate constant is 0.022 min-1.

  3. Direct Imaging of ER Calcium with Targeted-Esterase Induced Dye Loading (TED)

    Science.gov (United States)

    Samtleben, Samira; Jaepel, Juliane; Fecher, Caroline; Andreska, Thomas; Rehberg, Markus; Blum, Robert

    2013-01-01

    Visualization of calcium dynamics is important to understand the role of calcium in cell physiology. To examine calcium dynamics, synthetic fluorescent Ca2+ indictors have become popular. Here we demonstrate TED (= targeted-esterase induced dye loading), a method to improve the release of Ca2+ indicator dyes in the ER lumen of different cell types. To date, TED was used in cell lines, glial cells, and neurons in vitro. TED bases on efficient, recombinant targeting of a high carboxylesterase activity to the ER lumen using vector-constructs that express Carboxylesterases (CES). The latest TED vectors contain a core element of CES2 fused to a red fluorescent protein, thus enabling simultaneous two-color imaging. The dynamics of free calcium in the ER are imaged in one color, while the corresponding ER structure appears in red. At the beginning of the procedure, cells are transduced with a lentivirus. Subsequently, the infected cells are seeded on coverslips to finally enable live cell imaging. Then, living cells are incubated with the acetoxymethyl ester (AM-ester) form of low-affinity Ca2+ indicators, for instance Fluo5N-AM, Mag-Fluo4-AM, or Mag-Fura2-AM. The esterase activity in the ER cleaves off hydrophobic side chains from the AM form of the Ca2+ indicator and a hydrophilic fluorescent dye/Ca2+ complex is formed and trapped in the ER lumen. After dye loading, the cells are analyzed at an inverted confocal laser scanning microscope. Cells are continuously perfused with Ringer-like solutions and the ER calcium dynamics are directly visualized by time-lapse imaging. Calcium release from the ER is identified by a decrease in fluorescence intensity in regions of interest, whereas the refilling of the ER calcium store produces an increase in fluorescence intensity. Finally, the change in fluorescent intensity over time is determined by calculation of ΔF/F0. PMID:23685703

  4. Direct imaging of ER calcium with targeted-esterase induced dye loading (TED).

    Science.gov (United States)

    Samtleben, Samira; Jaepel, Juliane; Fecher, Caroline; Andreska, Thomas; Rehberg, Markus; Blum, Robert

    2013-05-07

    Visualization of calcium dynamics is important to understand the role of calcium in cell physiology. To examine calcium dynamics, synthetic fluorescent Ca(2+) indictors have become popular. Here we demonstrate TED (= targeted-esterase induced dye loading), a method to improve the release of Ca(2+) indicator dyes in the ER lumen of different cell types. To date, TED was used in cell lines, glial cells, and neurons in vitro. TED bases on efficient, recombinant targeting of a high carboxylesterase activity to the ER lumen using vector-constructs that express Carboxylesterases (CES). The latest TED vectors contain a core element of CES2 fused to a red fluorescent protein, thus enabling simultaneous two-color imaging. The dynamics of free calcium in the ER are imaged in one color, while the corresponding ER structure appears in red. At the beginning of the procedure, cells are transduced with a lentivirus. Subsequently, the infected cells are seeded on coverslips to finally enable live cell imaging. Then, living cells are incubated with the acetoxymethyl ester (AM-ester) form of low-affinity Ca(2+) indicators, for instance Fluo5N-AM, Mag-Fluo4-AM, or Mag-Fura2-AM. The esterase activity in the ER cleaves off hydrophobic side chains from the AM form of the Ca(2+) indicator and a hydrophilic fluorescent dye/Ca(2+) complex is formed and trapped in the ER lumen. After dye loading, the cells are analyzed at an inverted confocal laser scanning microscope. Cells are continuously perfused with Ringer-like solutions and the ER calcium dynamics are directly visualized by time-lapse imaging. Calcium release from the ER is identified by a decrease in fluorescence intensity in regions of interest, whereas the refilling of the ER calcium store produces an increase in fluorescence intensity. Finally, the change in fluorescent intensity over time is determined by calculation of ΔF/F0.

  5. Relationship between changes of N-methyl-D-aspartate receptor activity and brain edema after brain injury in rats

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To investigate the relationship between the changes of N-methyl-D-aspartate (NMDA) receptor activity and brain edema after injury in rats.   Methods: The brain injury models were made by using a free-falling body. The treatment model was induced by means of injecting AP5 into lateral ventricle before brain injury; water contents in brain cortex were measured with dry-wet method; and NMDA receptor activity was detected with a radio ligand binding assay.   Results: The water contents began to increase at 30 minutes and reached the peak at 6 hours after brain injury. The maximal binding (Bmax) of NMDA receptor increased significantly at 15 minutes and reached the peak at 30 minutes, then decreased gradually and had the lowest value 6 hours after brain injury. Followed the treatment with AP5, NMDA receptor activity in the injured brain showed a normal value; and the water contents were lower than that of AP5-free injury group 24 hours after brain injury.   Conclusions: It suggests that excessive activation of NMDA receptor may be one of the most important factors to induce the secondary cerebral impairments, and AP5 may protect the brain from edema after brain injury.

  6. Effects of temperature, ultraviolet radiation and pectin methyl esterase on aerobic methane release from plant material

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Øbro, J.

    2009-01-01

    exponentially on temperature and linearly on UV-B irradiance. UV-B had a greater stimulating effect than UV-A, while visible light had no effect on emission rates. PME was found to substantially reduce the potential for aerobic CH4 emissions upon demethylation of pectin....

  7. A novel esterase gene cloned from a metagenomic library from neritic sediments of the South China Sea

    Science.gov (United States)

    2011-01-01

    Background Marine microbes are a large and diverse group, which are exposed to a wide variety of pressure, temperature, salinity, nutrient availability and other environmental conditions. They provide a huge potential source of novel enzymes with unique properties that may be useful in industry and biotechnology. To explore the lipolytic genetic resources in the South China Sea, 23 sediment samples were collected in the depth South China Sea sediments assemblage in plasmid vector containing about 194 Mb of community DNA was prepared. Screening of a part of the unamplified library resulted in isolation of 15 unique lipolytic clones with the ability to hydrolyze tributyrin. A positive recombinant clone (pNLE1), containing a novel esterase (Est_p1), was successfully expressed in E. coli and purified. In a series of assays, Est_p1 displayed maximal activity at pH 8.57, 40°C, with ρ-Nitrophenyl butyrate (C4) as substrate. Compared to other metagenomic esterases, Est_p1 played a notable role in specificity for substrate C4 (kcat/Km value 11,500 S-1m M-1) and showed no inhibited by phenylmethylsulfonyl fluoride, suggested that the substrate binding pocket was suitable for substrate C4 and the serine active-site residue was buried at the bottom of substrate binding pocket which sheltered by a lid structure. Conclusions Esterase, which specificity towards short chain fatty acids, especially butanoic acid, is commercially available as potent flavoring tools. According the outstanding activity and specificity for substrate C4, Est_p1 has potential application in flavor industries requiring hydrolysis of short chain esters. PMID:22067554

  8. Alpha-Adrenoceptor Antagonists Improve Memory by Activating -methyl-D-Aspartate-Induced Ion Currents in the Rat Hippocampus

    Directory of Open Access Journals (Sweden)

    Chang Hee Kim

    2015-12-01

    Full Text Available Purpose: Alpha1 (α1-adrenoceptor antagonists are widely used to treat lower urinary tract symptoms. These drugs not only act on peripheral tissues, but also cross the blood-brain barrier and affect the central nervous system. Therefore, α1-adrenoceptor antagonists may enhance brain functions. In the present study, we investigated the effects of tamsulosin, an α1-adrenoceptor antagonist, on short-term memory, as well as spatial learning and memory, in rats. Methods: The step-down avoidance test was used to evaluate short-term memory, and an eight-arm radial maze test was used to evaluate spatial learning and memory. TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling staining was performed in order to evaluate the effect of tamsulosin on apoptosis in the hippocampal dentate gyrus. Patch clamp recordings were used to evaluate the effect of tamsulosin on ionotropic glutamate receptors, such as N-methyl-D-aspartate (NMDA, amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA, and kainate receptors, in hippocampal CA1 neurons. Results: Tamsulosin treatment improved short-term memory, as well as spatial learning and memory, without altering apoptosis. The amplitudes of NMDA-induced ion currents were dose-dependently increased by tamsulosin. However, the amplitudes of AMPA- and kainate-induced ion currents were not affected by tamsulosin. Conclusions: Tamsulosin enhanced memory function by activating NMDA receptor-mediated ion currents in the hippocampus without initiating apoptosis. The present study suggests the possibility of using tamsulosin to enhance memory under normal conditions, in addition to its use in treating overactive bladder.

  9. Heterogeneous Photochemistry of Agrochemicals at the Leaf Surface: A Case Study of Plant Activator Acibenzolar-S-methyl.

    Science.gov (United States)

    Sleiman, M; de Sainte Claire, P; Richard, C

    2017-09-06

    The photoreactivity of plant activator benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), commonly named acibenzolar-S-methyl, was studied on the surfaces of glass, paraffinic wax films, and apple leaves. Experiments were carried out in a solar simulator using pure and formulated BTH (BION). Surface photoproducts were identified using liquid chromatography coupled with electrospray ionization and high-resolution Orbitrap mass spectrometry, while volatile photoproducts were characterized using an online thermal desorption system coupled to a gas chromatography-mass spectrometry (GC-MS) system. Pure BTH degraded quickly on wax surfaces with a half-life of 5.0 ± 0.5 h, whereas photolysis of formulated BTH was 7 times slower (t 1/2 = 36 ± 14 h). On the other hand, formulated BTH was found to photolyze quickly on detached apple leaves with a half-life of 2.8 h ± 0.4 h. This drastic difference in photoreactivity was attributed to the nature and spreading of the BTH deposit, as influenced by the surfactant and surface characteristics. Abiotic stress of irradiated apple leaf was also shown to produce OH radicals which might contribute to the enhanced photodegradability. Eight surface photoproducts were identified, whereas GC-MS analyses revealed the formation of gaseous dimethyl disulfide and methanethiol. The yield of dimethyl disulfide ranged between 1.5% and 12%, and a significant fraction of dimethyl disulfide produced was found to be absorbed by the leaf. This is the first study to report on the formation of volatile chemicals and OH radicals during agrochemical photolysis on plant surfaces. The developed experimental approach can provide valuable insights into the heterogeneous photoreactivity of sprayed agrochemicals and could help improve dissipation models.

  10. One-night sleep deprivation induces changes in the DNA methylation and serum activity indices of stearoyl-CoA desaturase in young healthy men.

    Science.gov (United States)

    Skuladottir, Gudrun Valgerdur; Nilsson, Emil Karl; Mwinyi, Jessica; Schiöth, Helgi Birgir

    2016-08-26

    Sleep deprivation has been associated with obesity among adults, and accumulating data suggests that stearoyl-CoA desaturase 1 (SCD1) expression has a relevant impact on fatty acid (FA) composition of lipid pools and obesity. The aim of this study was to investigate the effect of one-night total sleep deprivation (TSD) on DNA methylation in the 5'-prime region of SCD1, and whether detected changes in DNA methylation are associated with SCD activity indices (product to precursor FA ratios; 16:1n-7/16:0 and 18:1n-9/18:0) derived from serum phospholipids (PL). Sixteen young, normal-weight, healthy men completed two study sessions, one with one-night TSD and one with one-night normal sleep (NS). Sleep quality and length was assessed by polysomnography, and consisted of electroencephalography, electrooculography, and electromyography. Fasting whole blood samples were collected on the subsequent morning for analysis of DNA methylation and FAs in serum PL. Linear regression analyses were performed to assess the association between changes in DNA methylation and SCD activity indices. Three CpG sites close to the transcription start site (TSS) of SCD1 (cg00954566, cg24503796, cg14089512) were significantly differentially methylated in dependency of sleep duration (-log10 P-value > 1.3). Both SCD-16 and SCD-18 activity indices were significantly elevated (P DNA methylation changes of the three mentioned probes in the 5' region of SCD1. Our results suggest a relevant link between TSD, hepatic SCD1 expression and de-novo fatty acid synthesis via epigenetically driven regulatory mechanisms.

  11. Enhanced visible light photocatalytic activity of copper-doped titanium oxide-zinc oxide heterojunction for methyl orange degradation

    Science.gov (United States)

    Dorraj, Masoumeh; Alizadeh, Mahdi; Sairi, Nor Asrina; Basirun, Wan Jefrey; Goh, Boon Tong; Woi, Pei Meng; Alias, Yatimah

    2017-08-01

    A novel Cu-doped TiO2 coupled with ZnO nanoparticles (Cu-TiO2/ZnO) was prepared by sol-gel method and subsequent precipitation for methyl orange (MO) photodegradation under visible light irradiation. The compositions and shapes of the as-prepared Cu-TiO2/ZnO nanocomposites were characterized by photoluminescence spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra and Brunauer-Emmett-Teller adsorption isotherm techniques. The Cu-TiO2/ZnO nanocomposites showed considerably higher photocatalytic activity for MO removal from water under visible light irradiation than that of single-doped semiconductors. The effects of Cu-TiO2 and ZnO mass ratios on the photocatalytic reaction were also studied. A coupling percentage of 30% ZnO exhibited the highest photocatalytic activity. The enhanced photocatalytic activity of the Cu-TiO2/ZnO nanocomposites was mainly attributed to heterojunction formation, which allowed the efficient separation of photoinduced electron-hole pairs at the interface. Moreover, these novel nanocomposites could be recycled during MO degradation in a three-cycle experiment without evident deactivation, which is particularly important in environmental applications.

  12. Biotransformation of Bicyclic Halolactones with a Methyl Group in the Cyclohexane Ring into Hydroxylactones and Their Biological Activity

    Directory of Open Access Journals (Sweden)

    Katarzyna Wińska

    2016-10-01

    Full Text Available The aim of this study was the chemical synthesis of a series of halo- and unsaturated lactones, as well as their microbial transformation products. Finally some of their biological activities were assessed. Three bicyclic halolactones with a methyl group in the cyclohexane ring were obtained from the corresponding γ,δ-unsaturated ester during a two-step synthesis. These lactones were subjected to screening biotransformation using twenty two fungal strains. These strains were tested on their ability to transform halolactones into new hydroxylactones. Among the six strains able to catalyze hydrolytic dehalogenation, only two (Fusarium equiseti, AM22 and Yarrowia lipolytica, AM71 gave a product in a high yield. Moreover, one strain (Penicillium wermiculatum, AM30 introduced the hydroxy group on the cyclohexane ring without removing the halogen atom. The biological activity of five of the obtained lactones was tested. Some of these compounds exhibited growth inhibition against bacteria, yeasts and fungi and deterrent activity against peach-potato aphid.

  13. Pretreatment of Parsley (Petroselinum crispum L.) Suspension Cultures with Methyl Jasmonate Enhances Elicitation of Activated Oxygen Species.

    Science.gov (United States)

    Kauss, H.; Jeblick, W.; Ziegler, J.; Krabler, W.

    1994-01-01

    Suspension-cultured cells of parsley (Petroselinum crispum L.) were used to demonstrate an influence of jasmonic acid methyl ester (JAME) on the elicitation of activated oxygen species. Preincubation of the cell cultures for 1 d with JAME greatly enhanced the subsequent induction by an elicitor preparation from cell walls of Phytophtora megasperma f. sp. glycinea (Pmg elicitor) and by the polycation chitosan. Shorter preincubation times with JAME were less efficient, and the effect was saturated at about 5 [mu]M JAME. Treatment of the crude Pmg elicitor with trypsin abolished induction of activated oxygen species, an effect similar to that seen with elicitation of coumarin secretion. These results suggest that JAME conditioned the parsley suspension cells in a time-dependent manner to become more responsive to elicitation, reminiscent of developmental effects caused by JAME in whole plants. It is interesting that pretreatment of the parsley cultures with 2,6-dichloroisonicotinic and 5-chlorosalicylic acid only slightly enhanced the elicitation of activated oxygen species, whereas these substances greatly enhanced the elicitation of coumarin secretion. Therefore, these presumed inducers of systemic acquired resistance exhibit a specificity different from JAME. PMID:12232189

  14. Redox-active quinones induces genome-wide DNA methylation changes by an iron-mediated and Tet-dependent mechanism

    DEFF Research Database (Denmark)

    Zhao, Bailin; Yang, Ying; Wang, Xiaoli

    2014-01-01

    DNA methylation has been proven to be a critical epigenetic mark important for various cellular processes. Here, we report that redox-active quinones, a ubiquitous class of chemicals found in natural products, cancer therapeutics and environment, stimulate the conversion of 5 mC to 5 hmC in vivo,...

  15. Antioxidant activity of gallic acid and methyl gallate in triacylglycerols of Kilka fish oil and its oil-in-water emulsion.

    Science.gov (United States)

    Asnaashari, Maryam; Farhoosh, Reza; Sharif, Ali

    2014-09-15

    The anti-DPPH radical effect as well as anti-peroxide activity of gallic acid, methyl gallate, and α-tocopherol in a bulk Kilka fish oil and its oil-in-water emulsion stabilized by soy protein isolate at 55°C were investigated. Gallic acid with the lowest hydrophobicity (log P=-0.28) was found to be the most active antiradical agent (IC50=29.5 μM), followed by methyl gallate (IC50=38.0 μM, log P=-0.23) and α-tocopherol (IC50=105.3 μM, log P=0.70). The anti-peroxide activity in the bulk oil system decreased in the order of methyl gallate>gallic acid>α-tocopherol. In the emulsion system, methyl gallate still behaved better than gallic acid, but the highest activity belonged to α-tocopherol. Based on the calculation of a number of kinetic parameters, the antioxidants, in general, showed better performances in the bulk oil system than in the emulsion system. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Inhibition, recovery and oxime-induced reactivation of muscle esterases following chlorpyrifos exposure in the earthworm Lumbricus terrestris

    International Nuclear Information System (INIS)

    Collange, B.; Wheelock, C.E.; Rault, M.; Mazzia, C.; Capowiez, Y.; Sanchez-Hernandez, J.C.

    2010-01-01

    Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus terrestris exposed to chlorpyrifos, and the ability of oximes to reactivate the phosphorylated ChE activity. Results indicated that these esterase activities are a suitable multibiomarker scheme for monitoring OP exposure due to their high sensitivity to OP inhibition and slow recovery to full activity levels following pesticide exposure. Moreover, oximes reactivated the inhibited ChE activity of the earthworms exposed to 12 and 48 mg kg -1 chlorpyrifos during the first week following pesticide exposure. This methodology is useful for providing evidence for OP-mediated ChE inhibition in individuals with a short history of OP exposure (≤1 week); resulting a valuable approach for assessing multiple OP exposure episodes in the field. - Esterase inhibition combined with oxime reactivation methods is a suitable approach for monitoring organophosphate contamination

  17. Inhibition, recovery and oxime-induced reactivation of muscle esterases following chlorpyrifos exposure in the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Collange, B. [Universite d' Avignon et des Pays de Vaucluse, UMR 406 Abeilles et Environnement, Site AGROPARC, F-84914, Avignon Cede 09 (France); Wheelock, C.E. [Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm (Sweden); Rault, M.; Mazzia, C. [Universite d' Avignon et des Pays de Vaucluse, UMR 406 Abeilles et Environnement, Site AGROPARC, F-84914, Avignon Cede 09 (France); Capowiez, Y. [INRA, Unite PSH, Site AGROPARC, F-84914 Avignon Cedex 09 (France); Sanchez-Hernandez, J.C., E-mail: juancarlos.sanchez@uclm.e [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071, Toledo (Spain)

    2010-06-15

    Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus terrestris exposed to chlorpyrifos, and the ability of oximes to reactivate the phosphorylated ChE activity. Results indicated that these esterase activities are a suitable multibiomarker scheme for monitoring OP exposure due to their high sensitivity to OP inhibition and slow recovery to full activity levels following pesticide exposure. Moreover, oximes reactivated the inhibited ChE activity of the earthworms exposed to 12 and 48 mg kg{sup -1} chlorpyrifos during the first week following pesticide exposure. This methodology is useful for providing evidence for OP-mediated ChE inhibition in individuals with a short history of OP exposure (<=1 week); resulting a valuable approach for assessing multiple OP exposure episodes in the field. - Esterase inhibition combined with oxime reactivation methods is a suitable approach for monitoring organophosphate contamination

  18. The role of Ca2+ and Mg2+ in the cytotoxic T lymphocyte reaction and in the secretion of N alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester-serine esterase by human T cell clones

    NARCIS (Netherlands)

    Blanchard, D.; Aubry, J. P.; de Vries, J. E.; Spits, H.

    1989-01-01

    Human T cell clones contain enzymes that can cleave the substrate N-alpha-benzyloxycarbonyl-L-lysine thiobenzyl ester (BLT). All CTL clones tested in this study secreted BLT-serine esterase activity, whereas only one of three tested non-cytolytic T cell clones secreted this enzymatic activity upon

  19. Antimycobacterial Activities of Novel 5-(1H-1,2,3-TriazolylMethyl Oxazolidinones

    Directory of Open Access Journals (Sweden)

    Oludotun Adebayo Phillips

    2012-01-01

    Full Text Available The antibacterial activities of a series of triazolyl oxazolidinones against Mycobacterium tuberculosis strain in vitro and in vivo in a mice model are presented. Most active compounds were noncytotoxic against VERO cells with acceptable selectivity indexes (SI as measures of compound tolerability. Structure activity relationships (SARs revealed that analogs with alkylcarbonyl (IC90: < 0.2 to 0.422 μg/mL and arylcarbonyl (IC90: < 0.2 to 2.103 μg/mL groups at the piperazine 4N-position-displayed potent antimycobacterium activities, comparable to the methanesulfonyl (IC90: < 0.2 μg/mL analog, linezolid (IC90: < 0.2 μg/mL, and isoniazid (IC90: < 0.034 μg/mL. The furanylcarbonyl derivative also displayed potent activity, while the arylsulfonyl analogs were inactive. Of the triazolyl oxazolidinones, the morpholino (PH-27 derivative with medium bioavailability in plasma was most active in vivo, but relatively less efficacious than isoniazid.

  20. Radical scavenging potential, antiinflammatory and antiarthritic activity of isolated isomer Methyl-γ-Orsellinate and roccellatol from Roccella montagnei Bel

    Directory of Open Access Journals (Sweden)

    Syed Zameer Ahmed Khader

    2018-06-01

    Full Text Available The burden of multiple drug resistance towards chronic diseases is rapidly increasing globally at an alarm rate. The present study aims to isolate active principles via bioassay guided fractionation of traditionally used lichen Roccella montagnei for in vitro radical scavenging activity with potential to combat arthritis and inflammation. The results of proximate composition and mineral analysis revealed the presence of essential amount of micro and macro nutrients which are required for secondary metabolite production. Fractions of Roccella montagnei and pure compounds were assessed for its in vitro antioxidant (DPPH, FRAP, OH radical, SOD, CAT, GPX, antiarthritic and antiinflammatory activity. The results indicates that lichen sample and fractions exhibited potent radical scavenger demonstrated in vitro antiarthritic and antiinflammatory activity in dose dependent manner. Bioassay fractionation lead to isolation of two pure compounds ie., Compound I and Compound II which were characterized using spectral data such as FT-IR, 1H NMR, 13C NMR, DEPT NMR spectroscopy, COSY & HMQC NMR spectroscopy and LC-MS analysis and was identified as Methyl-γ-Orsellinate (C9H10O4 a novel isomer from fractions E2d5a with a molecular weight of 182.2 and Roccellatol (C12H16O7 from fractions D3d4c with a molecular weight of 272.3. The present findings suggest that the secondary metabolites present in the lichens have direct relation, with biological activities revealing different properties and can be a future novel antioxidant and a potent anti-arthritic agent.

  1. Intracellular and membrane-damaging activities of methyl gallate isolated from Terminalia chebula against multidrug-resistant Shigella spp.

    Science.gov (United States)

    Acharyya, Saurabh; Sarkar, Prodipta; Saha, Dhira R; Patra, Amarendra; Ramamurthy, T; Bag, Prasanta K

    2015-08-01

    Shigella spp. (Shigella dysenteriae, Shigella flexneri, Shigella boydii and Shigella sonnei) cause bacillary dysentery (shigellosis), which is characterized by bloody mucous diarrhoea. Although a variety of antibiotics have been effective for treatment of shigellosis, options are becoming limited due to globally emerging drug resistance. In the present study, in vitro antibacterial activity of methyl gallate (MG) isolated from Terminalia chebula was determined by performing MIC, minimal bactericidal concentration (MBC) and time-kill kinetic studies. Bacterial membrane-damaging activity of MG was determined by membrane perturbation and transmission electron microscopy (TEM). Cellular drug accumulation, cell infection and assessment of intracellular activities of MG and reference antibiotics were performed using HeLa cell cultures. The bactericidal activity of MG against multidrug-resistant (MDR) Shigella spp. in comparison with other commonly used drugs including fluoroquinolone was demonstrated here. TEM findings in the present study revealed that MG caused the total disintegration of inner and outer membranes, and leakage of the cytoplasmic contents of S. dysenteriae. The level of accumulation of MG and tetracycline in HeLa cells incubated for 24  h was relatively higher than that of ciprofloxacin and nalidixic acid (ratio of intracellular concentration/extracellular concentration of antibiotic for MG and tetracycline>ciprofloxacin and nalidixic acid). The viable number of intracellular S. dysenteriae was decreased in a time-dependent manner in the presence of MG (4 × MBC) and reduced to zero within 20  h. The significant intracellular activities of MG suggested that it could potentially be used as an effective antibacterial agent for the treatment of severe infections caused by MDR Shigella spp.

  2. Evolution of the feruloyl esterase MtFae1a from Myceliophthora thermophila towards improved catalysts for antioxidants synthesis.

    Science.gov (United States)

    Varriale, Simona; Cerullo, Gabriella; Antonopoulou, Io; Christakopoulos, Paul; Rova, Ulrika; Tron, Thierry; Fauré, Régis; Jütten, Peter; Piechot, Alexander; Brás, Joana L A; Fontes, Carlos M G A; Faraco, Vincenza

    2018-04-23

    The chemical syntheses currently employed for industrial purposes, including in the manufacture of cosmetics, present limitations such as unwanted side reactions and the need for harsh chemical reaction conditions. In order to overcome these drawbacks, novel enzymes are developed to catalyze the targeted bioconversions. In the present study, a methodology for the construction and the automated screening of evolved variants library of a Type B feruloyl esterase from Myceliophthora thermophila (MtFae1a) was developed and applied to generation of 30,000 mutants and their screening for selecting the variants with higher activity than the wild-type enzyme. The library was generated by error-prone PCR of mtfae1a cDNA and expressed in Saccharomyces cerevisiae. Screening for extracellular enzymatic activity towards 4-nitrocatechol-1-yl ferulate, a new substrate developed ad hoc for high-throughput assays of feruloyl esterases, led to the selection of 30 improved enzyme variants. The best four variants and the wild-type MtFae1a were investigated in docking experiments with hydroxycinnamic acid esters using a model of 3D structure of MtFae1a. These variants were also used as biocatalysts in transesterification reactions leading to different target products in detergentless microemulsions and showed enhanced synthetic activities, although the screening strategy had been based on improved hydrolytic activity.

  3. The Aspergillus niger faeB gene encodes a second feruloyl esterase involved in pectin and xylan degradation and is specifically induced in the presence of aromatic compounds.

    Science.gov (United States)

    de Vries, Ronald P; vanKuyk, Patricia A; Kester, Harry C M; Visser, Jaap

    2002-04-15

    The faeB gene encoding a second feruloyl esterase from Aspergillus niger has been cloned and characterized. It consists of an open reading frame of 1644 bp containing one intron. The gene encodes a protein of 521 amino acids that has sequence similarity to that of an Aspergillus oryzae tannase. However, the encoded enzyme, feruloyl esterase B (FAEB), does not have tannase activity. Comparison of the physical characteristics and substrate specificity of FAEB with those of a cinnamoyl esterase from A. niger [Kroon, Faulds and Williamson (1996) Biotechnol. Appl. Biochem. 23, 255-262] suggests that they are in fact the same enzyme. The expression of faeB is specifically induced in the presence of certain aromatic compounds, but not in the presence of other constituents present in plant-cell-wall polysaccharides such as arabinoxylan or pectin. The expression profile of faeB in the presence of aromatic compounds was compared with the expression of A. niger faeA, encoding feruloyl esterase A (FAEA), and A. niger bphA, the gene encoding a benzoate-p-hydroxylase. All three genes have different subsets of aromatic compounds that induce their expression, indicating the presence of different transcription activating systems in A. niger that respond to aromatic compounds. Comparison of the activity of FAEA and FAEB on sugar-beet pectin and wheat arabinoxylan demonstrated that they are both involved in the degradation of both polysaccharides, but have opposite preferences for these substrates. FAEA is more active than FAEB towards wheat arabinoxylan, whereas FAEB is more active than FAEA towards sugar-beet pectin.

  4. Enhancement of lipase catalyzed-fatty acid methyl esters production from waste activated bleaching earth by nullification of lipase inhibitors.

    Science.gov (United States)

    Dwiarti, Lies; Ali, Ehsan; Park, Enoch Y

    2010-01-01

    This study sought to identify inhibitory factors of lipase catalyzed-fatty acid methyl esters (FAME) production from waste activated bleaching earth (wABE). During the vegetable oil refinery process, activated bleaching earth (ABE) is used for removing the impure compounds, but adsorbs vegetable oil up to 35-40% as on a weight basis, and then the wABE is discarded as waste material. The impurities were extracted from the wABE with methanol and evaluated by infra-red (IR) spectroscopy, which revealed that some were chlorophyll-plant pigments. The chlorophylls inhibited the lipase during FAME conversion from wABE. The inhibition by a mixture of chlorophyll a and b was found to be competitive. The inhibition of the enzymatic hydrolysis of waste vegetable oil contained in wABE by chlorophyll a alone was competitive, while the inhibition by chlorophyll b alone was non-competitive. Furthermore, the addition of a small amount of alkali nullified this inhibitory effect and accelerated the FAME production rate. When 0.9% KOH (w/w wABE) was added to the transesterification reaction with only 0.05% lipase (w/w wABE), the maximum FAME production rate improved 120-fold, as compared to that without the addition of KOH. The alkali-combined lipase significantly enhanced the FAME production rate from wABE, in spite of the presence of the plant pigments, and even when a lower amount of lipase was used as a catalyst.

  5. Fatty acid methyl ester (FAME) technology for monitoring biological foaming in activated sludge: full scale plant verification.

    Science.gov (United States)

    Lee, J W; Cha, D K; Kim, I; Son, A; Ahn, K H

    2008-02-01

    Fatty acid methyl ester (FAME) technology was evaluated as a monitoring tool for quantification of Gordonia amarae in activated sludge systems. The fatty acid, 19:1 alcohol, which was identified as a unique fatty acid in G. amarae was not only confirmed to be present in foaming plant samples, but the quantity of the signature peak correlated closely with the degree of foaming. Foaming potential experiment provided a range of critical foaming levels that corresponded to G. amarae population. This range of critical Gordonia levels was correlated to the threshold signature FAME amount. Six full-scale wastewater treatment plants were selected based on a survey to participate in our full-scale study to evaluate the potential application of the FAME technique as the Gordonia monitoring tool. Greater amounts of signature FAME were extracted from the mixed liquor samples obtained from treatment plants experiencing Gordonia foaming problems. The amounts of signature FAME correlated well with the conventional filamentous counting technique. These results demonstrated that the relative abundance of the signature FAMEs can be used to quantitatively monitor the abundance of foam-causing microorganism in activated sludge.

  6. Potential antimalarial activity of Methyl Jasmonate and its effect on lipid profiles in Plasmodium Berghei infected mice.

    Science.gov (United States)

    Oyinloye, Oladapo E; Kosoko, Ayokulehin M; Emikpe, Benjamin; Falade, Catherine O; Ademowo, Olusegun G

    2015-09-01

    The antimalarial activity and lipid profiles of Methyl Jasmonate (MJ) were investigated against established malaria infection in vivo using BALB/c mice. Arteether (AE) and chloroquine (CQ) were used as reference drugs while ethanol was used as the vehicle for drug delivery for MJ. Mice treated with 10 and 25 mg/kg MJ showed a remarkable reduction in percentage parasitemia by 68.3% and 78.2% on day 10(post treatment) respectively while 45.4% and 87.2% reduction in percentage parasitemia were observed in the group treated with 50 mg/kg on day 3 and 10 (post treatment) respectively. The highest mean survival time was observed in CQ followed by AE and MJ in dose-dependent manner. A progressive decrease in packed cell volume (PCV) was observed in infected untreated mice which led to the death of all the mice by day 9 (post treatment). Infected mice treated with MJ showed reduced level of HDL and LDL compared with infected untreated group. As the dose of MJ increased in infected mice cholesterol levels increased while there was reduction in triglyceride. Overall there was marked decrease in parasitemia in Plasmodium berghei infected mice treated with graded doses of MJ but appears to have reduced antimalarial activity compared with CQ and AE.

  7. Antigenotoxic and Antimutagenic Activities of Probiotic Lactobacillus rhamnosus Vc against N-Methyl-N'-Nitro-N-Nitrosoguanidine.

    Science.gov (United States)

    Pithva, Sheetal P; Ambalam, Padma S; Ramoliya, Jignesh M; Dave, Jayantilal M; Vyas, Bharatkumar Rajiv Manuel

    2015-01-01

    The present study provides experimental evidence of in vivo reduction of genotoxic and mutagenic activities of potent carcinogen N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) by the strain Lactobacillus rhamnosus Vc. In vitro studies revealed that coincubation of MNNG with viable cells of L. rhamnosus Vc resulted in the detoxification of the parent compound accompanied with reduction in genotoxicity (69%) and mutagenicity (61%) as evaluated by SOS-Chromotest and Ames test, respectively. Oral feeding of probiotic bacteria L. rhamnosus Vc (10(9) cfu) to Gallus gallus (chicks) for 30 days provided protection against MNNG-induced damage as evidenced from the significant decrease (P = 0.009) in glutathione S-transferase activity in the L. rhamnosus Vc+MNNG-treated chicks in comparison to the MNNG-treated chicks. Histopathology of colon and liver showed intact cells and mild inflammation in the L. rhamnosus Vc+MNNG-treated chicks, whereas heavy inflammation and degenerative changes were observed in MNNG-treated chicks. The results indicate that the probiotic L. rhamnosus Vc provided in vivo protection against MNNG-induced colon damage by detoxification of MNNG to less toxic metabolites.

  8. Studies on esterase isozymes and mycelium growth speed of ganoderma lucidum carried by Shenzhou spaceship

    International Nuclear Information System (INIS)

    Qi Jianjun; Chen Xiangdong; Lan Jin

    2002-01-01

    The esterase isozymes and mycelium growth speed of four Ganoderma lucidum strains carried by Shenzhou spaceship were studied. The results showed that different effects occurred to esterase and mycelium growth speed. The SX, S3 esterase band had changed compared with their control CX, C3, respectively, but there were no differences between SH and CH, S4 and C4. The growth speed of S4 strain was faster than its control C4, SX strain lower than its control CX, and there were no difference between SH and CH, S3 and C3

  9. Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol

    International Nuclear Information System (INIS)

    Miyano, Yoshimori; Kobashi, Takahiro; Shinjo, Hiroshi; Kumada, Shinya; Watanabe, Yusuke; Niya, Wataru; Tateishi, Yoko

    2006-01-01

    Henry's law constants and infinite dilution activity coefficients of cis-2-butene, dimethylether, chloroethane, and 1,1-difluoroethane in methanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, and 2-methyl-2-butanol in the temperature range of 250 K to 330 K were measured by a gas stripping method and partial molar excess enthalpies were calculated from the activity coefficients. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Poynting correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality

  10. Enhanced visible light photocatalytic activity of copper-doped titanium oxide–zinc oxide heterojunction for methyl orange degradation

    Energy Technology Data Exchange (ETDEWEB)

    Dorraj, Masoumeh, E-mail: masidor20@gmail.com [Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Alizadeh, Mahdi [UM Power Energy Dedicated Advanced Centre (UMPEDAC), Level 4 Wisma R& D, University of Malaya, Jalan Pantai Baharu, 59990 Kuala Lumpur (Malaysia); Sairi, Nor Asrina, E-mail: asrina@um.edu.my [Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); University of Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Basirun, Wan Jefrey [Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Goh, Boon Tong [Low Dimensional Materials Research Centre, Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Woi, Pei Meng; Alias, Yatimah [Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); University of Malaya Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2017-08-31

    Highlights: • The novel Cu-TiO{sub 2}/ZnO heterojunction nanocomposite was synthesized for the first time via a two-step process. • The Cu-TiO{sub 2}/ZnO heterostructured nanocomposite exhibited an enhanced visible-light-driven photocatalytic activity for MO degradation. • The heterostructured nanocomposite could be recycled during the degradation of MO in a three-cycle experiment with good stability. - Abstract: A novel Cu-doped TiO{sub 2} coupled with ZnO nanoparticles (Cu-TiO{sub 2}/ZnO) was prepared by sol-gel method and subsequent precipitation for methyl orange (MO) photodegradation under visible light irradiation. The compositions and shapes of the as-prepared Cu-TiO{sub 2}/ZnO nanocomposites were characterized by photoluminescence spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV–vis diffuse reflectance spectra and Brunauer–Emmett–Teller adsorption isotherm techniques. The Cu-TiO{sub 2}/ZnO nanocomposites showed considerably higher photocatalytic activity for MO removal from water under visible light irradiation than that of single-doped semiconductors. The effects of Cu-TiO{sub 2} and ZnO mass ratios on the photocatalytic reaction were also studied. A coupling percentage of 30% ZnO exhibited the highest photocatalytic activity. The enhanced photocatalytic activity of the Cu-TiO{sub 2}/ZnO nanocomposites was mainly attributed to heterojunction formation, which allowed the efficient separation of photoinduced electron−hole pairs at the interface. Moreover, these novel nanocomposites could be recycled during MO degradation in a three-cycle experiment without evident deactivation, which is particularly important in environmental applications.

  11. Murine T cell activation is regulated by surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide)

    Energy Technology Data Exchange (ETDEWEB)

    Warford, Jordan, E-mail: jordan.warford@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Doucette, Carolyn D., E-mail: carolyn.doucette@dal.ca [Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Hoskin, David W., E-mail: d.w.hoskin@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Easton, Alexander S., E-mail: alexander.easton@dal.ca [Department of Pathology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Microbiology and Immunology, Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Surgery (Neurosurgery), Dalhousie University, Tupper Building, 5850 College Street, Halifax, Nova Scotia B3H 4R2 (Canada)

    2014-01-10

    Highlights: •Surfen is the first inhibitor of glycosaminoglycan function to be studied in murine T cells. •Surfen reduces T cell proliferation stimulated in vitro and in vivo. •Surfen reduces CD25 expression in T cells activated in vivo but not in vitro. •Surfen increases T cell proliferation when T cell receptor activation is bypassed. •Surfen’s effects are blocked by co-administration of heparin sulfate. -- Abstract: Surfen (bis-2-methyl-4-amino-quinolyl-6-carbamide) binds to glycosaminoglycans (GAGs) and has been shown to influence their function, and the function of proteoglycans (complexes of GAGs linked to a core protein). T cells synthesize, secrete and express GAGs and proteoglycans which are involved in several aspects of T cell function. However, there are as yet no studies on the effect of GAG-binding agents such as surfen on T cell function. In this study, surfen was found to influence murine T cell activation. Doses between 2.5 and 20 μM produced a graduated reduction in the proliferation of T cells activated with anti-CD3/CD28 antibody-coated T cell expander beads. Surfen (20 mg/kg) was also administered to mice treated with anti-CD3 antibody to activate T cells in vivo. Lymphocytes from surfen-treated mice also showed reduced proliferation and lymph node cell counts were reduced. Surfen reduced labeling with a cell viability marker (7-ADD) but to a much lower extent than its effect on proliferation. Surfen also reduced CD25 (the α-subunit of the interleukin (IL)-2 receptor) expression with no effect on CD69 expression in T cells treated in vivo but not in vitro. When receptor activation was bypassed by treating T cells in vitro with phorbyl myristate acetate (10 ng/ml) and ionomycin (100 ng/ml), surfen treatment either increased proliferation (10 μM) or had no effect (2.5, 5 and 20 μM). In vitro treatment of T cells with surfen had no effect on IL-2 or interferon-γ synthesis and did not alter proliferation of the IL-2 dependent cell

  12. Efficient production of fatty acid methyl ester from waste activated bleaching earth using diesel oil as organic solvent.

    Science.gov (United States)

    Kojima, Seiji; Du, Dongning; Sato, Masayasu; Park, Enoch Y

    2004-01-01

    Fatty acid methyl ester (FAME) production from waste activated bleaching earth (ABE) discarded by the crude oil refining industry was investigated using fossil fuel as a solvent in the esterification of triglycerides. Lipase from Candida cylindracea showed the highest stability in diesel oil. Using diesel oil as a solvent, 3 h was sufficient to obtain a yield of approximately 100% of FAME in the presence of 10% lipase from waste ABE. Kerosene was also a good solvent in the esterification of triglycerides embedded in the waste ABE. Fuel analysis showed that the FAME produced using diesel oil as a solvent complied with the Japanese diesel standard and the 10% residual carbon amount was lower than that of FAME produced using other solvents. Use of diesel oil as solvent in the FAME production from the waste ABE simplified the process, because there was no need to separate the organic solvent from the FAME-solvent mixture. These results demonstrate a promising reutilization method for the production of FAME, for use as a biodiesel, from industrial waste resources containing waste vegetable oils.

  13. Low concentrations of salicylic acid delay methyl jasmonate-induced leaf senescence by up-regulating nitric oxide synthase activity.

    Science.gov (United States)

    Ji, Yingbin; Liu, Jian; Xing, Da

    2016-09-01

    In plants, extensive efforts have been devoted to understanding the crosstalk between salicylic acid (SA) and jasmonic acid (JA) signaling in pathogen defenses, but this crosstalk has scarcely been addressed during senescence. In this study, the effect of SA application on methyl jasmonate (MeJA)-induced leaf senescence was assessed. We found that low concentrations of SA (1-50 μM) played a delayed role against the senescence promoted by MeJA. Furthermore, low concentrations of SA enhanced plant antioxidant defenses and restricted reactive oxygen species (ROS) accumulation in MeJA-treated leaves. When applied simultaneously with MeJA, low concentrations of SA triggered a nitric oxide (NO) burst, and the elevated NO levels were linked to the nitric oxide associated 1 (NOA1)-dependent pathway via nitric oxide synthase (NOS) activity. The ability of SA to up-regulate plant antioxidant defenses, reduce ROS accumulation, and suppress leaf senescence was lost in NO-deficient Atnoa1 plants. In a converse manner, exogenous addition of NO donors increased the plant antioxidant capacity and lowered the ROS levels in MeJA-treated leaves. Taken together, the results indicate that SA at low concentrations counteracts MeJA-induced leaf senescence through NOA1-dependent NO signaling and strengthening of the antioxidant defense. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  14. N-Methyl-D-aspartate Receptor Excessive Activation Inhibited Fetal Rat Lung Development In Vivo and In Vitro

    Directory of Open Access Journals (Sweden)

    Zhengchang Liao

    2016-01-01

    Full Text Available Background. Intrauterine hypoxia is a common cause of fetal growth and lung development restriction. Although N-methyl-D-aspartate receptors (NMDARs are distributed in the postnatal lung and play a role in lung injury, little is known about NMDAR’s expression and role in fetal lung development. Methods. Real-time PCR and western blotting analysis were performed to detect NMDARs between embryonic days (E 15.5 and E21.5 in fetal rat lungs. NMDAR antagonist MK-801’s influence on intrauterine hypoxia-induced retardation of fetal lung development was tested in vivo, and NMDA’s direct effect on fetal lung development was observed using fetal lung organ culture in vitro. Results. All seven NMDARs are expressed in fetal rat lungs. Intrauterine hypoxia upregulated NMDARs expression in fetal lungs and decreased fetal body weight, lung weight, lung-weight-to-body-weight ratio, and radial alveolar count, whereas MK-801 alleviated this damage in vivo. In vitro experiments showed that NMDA decreased saccular circumference and area per unit and downregulated thyroid transcription factor-1 and surfactant protein-C mRNA expression. Conclusions. The excessive activation of NMDARs contributed to hypoxia-induced fetal lung development retardation and appropriate blockade of NMDAR might be a novel therapeutic strategy for minimizing the negative outcomes of prenatal hypoxia on lung development.

  15. Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, No Stack, More than 8 Hours

    Science.gov (United States)

    This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

  16. Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, Horizontal Stacks, 8 Hours or Less

    Science.gov (United States)

    This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

  17. Methyl Bromide Buffer Zone Distances for Commodity and Structural Fumigation: Active Aeration, No Stack, 8 Hours or Less

    Science.gov (United States)

    This document contains buffer zone tables required by certain methyl bromide commodity fumigant product labels that refer to Buffer Zone Lookup Tables located at epa.gov/pesticide-registration/mbcommoditybuffer on the label.

  18. Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location

    International Nuclear Information System (INIS)

    Hamers, T.; Brink, P.J. van den; Mos, L.; Linden, S.C. van der; Legler, J.; Koeman, J.H.; Murk, A.J.

    2003-01-01

    Estrogenic potency of rainwater correlated well with organochlorine concentrations, but could not be attributed to specific pesticides. - In a year-round monitoring program (1998), pesticide composition and toxic potency of the mix of pollutants present in rainwater were measured. The goal of the study was to relate atmospheric deposition of toxic potency and pesticide composition to each other and to sampling period and local agricultural activity. Rainwater was collected in 26 consecutive periods of 14 days in a background location (BACK) and in two locations representative for different agricultural practices, i.e. intensive greenhouse horticulture (HORT) and flower bulb culture (BULB). Samples were chemically analyzed for carbamate (CARB), organophosphate (OP) and organochlorine (OC) pesticides and metabolites. Esterase inhibiting potency of rainwater extracts was measured in a specially developed bio-assay with honeybee esterases and was expressed as an equivalent concentration of the model inhibitor dichlorvos. Estrogenic potency of the extracts was measured in the ER-CALUX reporter gene assay and was expressed as an equivalent concentration of estradiol. Multivariate principal component analysis (PCA) techniques proved to be valuable tools to analyze the numerous pesticide concentrations in relation to toxic potency, sampling location, and sampling season. Pesticide composition in rainwater depended much more on sampling season than on sampling location, but differences between SPRING and SUMMER were mainly attributed to local differences in agricultural practice. On average, the esterase inhibiting potency exceeded the maximum permissible concentration set for dichlorvos in The Netherlands, and was significantly higher in HORT than in BACK and BULB. Esterase inhibition correlated significantly with OP and CARB concentrations, as expected given the working mechanism of these insecticides. The estrogenic potency incidentally exceeded NOEC levels reported for

  19. Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, T.; Brink, P.J. van den; Mos, L.; Linden, S.C. van der; Legler, J.; Koeman, J.H.; Murk, A.J

    2003-05-01

    Estrogenic potency of rainwater correlated well with organochlorine concentrations, but could not be attributed to specific pesticides. - In a year-round monitoring program (1998), pesticide composition and toxic potency of the mix of pollutants present in rainwater were measured. The goal of the study was to relate atmospheric deposition of toxic potency and pesticide composition to each other and to sampling period and local agricultural activity. Rainwater was collected in 26 consecutive periods of 14 days in a background location (BACK) and in two locations representative for different agricultural practices, i.e. intensive greenhouse horticulture (HORT) and flower bulb culture (BULB). Samples were chemically analyzed for carbamate (CARB), organophosphate (OP) and organochlorine (OC) pesticides and metabolites. Esterase inhibiting potency of rainwater extracts was measured in a specially developed bio-assay with honeybee esterases and was expressed as an equivalent concentration of the model inhibitor dichlorvos. Estrogenic potency of the extracts was measured in the ER-CALUX reporter gene assay and was expressed as an equivalent concentration of estradiol. Multivariate principal component analysis (PCA) techniques proved to be valuable tools to analyze the numerous pesticide concentrations in relation to toxic potency, sampling location, and sampling season. Pesticide composition in rainwater depended much more on sampling season than on sampling location, but differences between SPRING and SUMMER were mainly attributed to local differences in agricultural practice. On average, the esterase inhibiting potency exceeded the maximum permissible concentration set for dichlorvos in The Netherlands, and was significantly higher in HORT than in BACK and BULB. Esterase inhibition correlated significantly with OP and CARB concentrations, as expected given the working mechanism of these insecticides. The estrogenic potency incidentally exceeded NOEC levels reported for

  20. DNA methylation

    DEFF Research Database (Denmark)

    Williams, Kristine; Christensen, Jesper; Helin, Kristian

    2012-01-01

    DNA methylation is involved in key cellular processes, including X-chromosome inactivation, imprinting and transcriptional silencing of specific genes and repetitive elements. DNA methylation patterns are frequently perturbed in human diseases such as imprinting disorders and cancer. The recent...... discovery that the three members of the TET protein family can convert 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC) has provided a potential mechanism leading to DNA demethylation. Moreover, the demonstration that TET2 is frequently mutated in haematopoietic tumours suggests that the TET...... proteins are important regulators of cellular identity. Here, we review the current knowledge regarding the function of the TET proteins, and discuss various mechanisms by which they contribute to transcriptional control. We propose that the TET proteins have an important role in regulating DNA methylation...

  1. Arsenic activates the expression of 3β-HSD in mouse Leydig cells through repression of histone H3K9 methylation

    Energy Technology Data Exchange (ETDEWEB)

    Alamdar, Ambreen; Xi, Guochen [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Huang, Qingyu, E-mail: qyhuang@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Centre for Epigenetics, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M (Denmark); Tian, Meiping [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Eqani, Syed Ali Musstjab Akber Shah [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Public Health and Environment Division, Department of Biosciences, COMSAT Institute of Information & Technology, Islamabad (Pakistan); Shen, Heqing, E-mail: hqshen@iue.ac.cn [Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China)

    2017-07-01

    Arsenic exposure has been associated with male reproductive dysfunction by disrupting steroidogenesis; however, the roles of epigenetic drivers, especially histone methylation in arsenic-induced steroidogenic toxicity remain not well documented. In this study, we investigated the role of histone H3 lysine 9 (H3K9) methylation in steroidogenesis disturbance in mouse Leydig cells (MLTC-1) due to arsenic exposure. Our results indicated that mRNA and protein expression levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) were both significantly up-regulated while the rest of key genes involved in steroidogenesis were down-regulated. Moreover, arsenic exposure significantly decreased the histone H3K9 di- and tri-methylation (H3K9me2/3) levels in MLTC-1 cells. Since H3K9 demethylation leads to gene activation, we further investigated whether the induction of 3β-HSD expression was ascribed to reduced H3K9 methylation. The results showed that H3K9me2/3 demethylase (JMJD2A) inhibitor, quercetin (Que) significantly attenuated the decrease of H3K9me2/3 and increase of 3β-HSD expression induced by arsenic. To further elucidate the mechanism for the activation of 3β-HSD, we determined the histone H3K9 methylation levels in Hsd3b gene promoter, which also showed significant decrease of H3K9me2/3 in the investigated region after arsenic exposure. Considering these results, we conclude that arsenic exposure induced 3β-HSD up-regulation by suppressing H3K9me2/3 status, which is suggested as a compensatory mechanism for steroidogenic disturbance in MLTC-1 cells. - Highlights: • Epigenetic mechanisms of arsenic-induced male reproductive toxicity remain unclear. • Arsenic disturbs the expression of key steroidogenic genes in MLTC-1 cells. • Histone H3K9 di- and tri-methylation was suppressed in arsenic-exposed cells. • Arsenic activates 3β-HSD expression through repression of histone H3K9 methylation.

  2. Arsenic activates the expression of 3β-HSD in mouse Leydig cells through repression of histone H3K9 methylation

    International Nuclear Information System (INIS)

    Alamdar, Ambreen; Xi, Guochen; Huang, Qingyu; Tian, Meiping; Eqani, Syed Ali Musstjab Akber Shah; Shen, Heqing

    2017-01-01

    Arsenic exposure has been associated with male reproductive dysfunction by disrupting steroidogenesis; however, the roles of epigenetic drivers, especially histone methylation in arsenic-induced steroidogenic toxicity remain not well documented. In this study, we investigated the role of histone H3 lysine 9 (H3K9) methylation in steroidogenesis disturbance in mouse Leydig cells (MLTC-1) due to arsenic exposure. Our results indicated that mRNA and protein expression levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) were both significantly up-regulated while the rest of key genes involved in steroidogenesis were down-regulated. Moreover, arsenic exposure significantly decreased the histone H3K9 di- and tri-methylation (H3K9me2/3) levels in MLTC-1 cells. Since H3K9 demethylation leads to gene activation, we further investigated whether the induction of 3β-HSD expression was ascribed to reduced H3K9 methylation. The results showed that H3K9me2/3 demethylase (JMJD2A) inhibitor, quercetin (Que) significantly attenuated the decrease of H3K9me2/3 and increase of 3β-HSD expression induced by arsenic. To further elucidate the mechanism for the activation of 3β-HSD, we determined the histone H3K9 methylation levels in Hsd3b gene promoter, which also showed significant decrease of H3K9me2/3 in the investigated region after arsenic exposure. Considering these results, we conclude that arsenic exposure induced 3β-HSD up-regulation by suppressing H3K9me2/3 status, which is suggested as a compensatory mechanism for steroidogenic disturbance in MLTC-1 cells. - Highlights: • Epigenetic mechanisms of arsenic-induced male reproductive toxicity remain unclear. • Arsenic disturbs the expression of key steroidogenic genes in MLTC-1 cells. • Histone H3K9 di- and tri-methylation was suppressed in arsenic-exposed cells. • Arsenic activates 3β-HSD expression through repression of histone H3K9 methylation.

  3. Fitness differences due to allelic variation at Esterase-4 locus in ...

    Indian Academy of Sciences (India)

    KAVITA KRISHNAMOORTI

    2017-08-31

    Aug 31, 2017 ... Keywords. esterases; null allele; reproductive fitness; natural selection; Drosophila ananassae. .... cific substrate (1-naphthylacetate AR) and stain (fast blue. RR). On the ... transferred to fresh food vials and eggs were counted.

  4. Common and Distant Structural Characteristics of Feruloyl Esterase Families from Aspergillus oryzae

    DEFF Research Database (Denmark)

    Udatha, D. B. R. K. Gupta; Mapelli, Valeria; Panagiotou, Gianni

    2012-01-01

    Background: Feruloyl esterases (FAEs) are important biomass degrading accessory enzymes due to their capability of cleaving the ester links between hemicellulose and pectin to aromatic compounds of lignin, thus enhancing the accessibility of plant tissues to cellulolytic and hemicellulolytic...

  5. Esterase-sensitive sulfur dioxide prodrugs inspired by modified Julia olefination.

    Science.gov (United States)

    Wang, Wenyi; Wang, Binghe

    2017-09-12

    Sulfur dioxide (SO 2 ) is an endogenously produced gaseous molecule, and is emerging as a potential gasotransmitter. Herein, we describe the first series of esterase-sensitive prodrugs inspired by modified Julia olefination as SO 2 donors.

  6. Esterase-D and chromosome patterns in Central Amazon piranha (Serrasalmus rhombeus Linnaeus, 1766 from Lake Catalão

    Directory of Open Access Journals (Sweden)

    Aylton Saturnino Teixeira

    2006-01-01

    Full Text Available This study presents additional genetic data on piranha (Serrasalmus rhombeus Linnaeus, 1766 complex previously diagnosed due to the presence of distinct cytotypes 2n = 58 and 2n = 60. Three esterase-D enzyme loci (Est-D1, Est-D2 and Est-D3 were examined and complemented with chromosomal data from 66 piranha specimens collected from Lake Catalão. For all specimens the Est-D1 and Est-D2 loci were monomorphic. In contrast, the Est-D3 locus was polymorphic with genotypes and alleles being differentially distributed in the previously described cytotypes and served as the basis for detecting a new cytotype (2n = 60 B. In cytotype 2n = 58 the Est-D3 locus was also polymorphic and presented Mendelian allelic segregation with four genotypes (Est-D3(11, Est-D3(12, Est-D3(22 and Est-D3(33 out of six theoretically possible genotypes, presumably encoded by alleles Est-D3¹ (frequency = 0.237, EsT-D3² (0.710 and Est-D3³ (0.053. A Chi-squared (chi2 test for Hardy-Weinberg equilibrium was applied to the Est-D3 locus and revealed a genetic unbalance in cytotype 2n = 58, indicating the probable existence in the surveyed area of different stocks for that karyotypic structure. A silent null allele (Est-D3(0 with a high frequency (0.959 occurred exclusively in the 2n = 60 cytotype. On the other hand, the new cytotype 2n = 60 B described here for the first time was monomorphic for the presumably fixed Est-D3³ allele. The data as a whole should contribute to the better understanding the rhombeus complex taxonomic status definition in the Central Amazon.

  7. Effect of NaHCO3 treatments on the activity of cell wall-degrading enzymes produced by Penicillium digitatum during the pathogenesis process on grapefruit.

    Science.gov (United States)

    Venditti, Tullio; D'hallewin, Guy; Ladu, Gianfranca; Petretto, Giacomo L; Pintore, Giorgio; Labavitch, John M

    2018-03-25

    The present study was performed to clarify the strategies of Penicillium digitatum during pathogenesis on citrus, assessing, on albedo plugs, the effects of treatment with NaHCO 3 , at two different pH (5 and 8.3), on cell wall-degrading enzymes activity, over a period of 72 h. The treatment with NaHCO 3 , under alkaline pH, delayed the polygalacturonase activity for 72 h, or 48 h in the case of the pectin lyase, if compared to the control or the same treatment at pH 5. On the contrary, the pectin methyl esterase activity rapidly increased after 24 h, in plugs dipped in the same solution. In this case, the activity remained higher than untreated or pH 5 treated plugs up to 72 h. The rapid increase in pectin methyl esterase activity, under alkaline conditions, is presumably the strategy of the pathogen to lower the pH, soon after the initiation of infection, in order to restore an optimal environment for the subsequent polygalacturonase and pectin lyase action. In fact at the same time, a low pH delayed the enzymatic activity of polygalacturonase and pectin lyase, the two enzymes that actually cleave the α-1,4-linkages between the galacturonic acid residues. This article is protected by copyright. All rights reserved.

  8. Biodegradation of methyl tertiary butyl ether (MTBE) using a granular activated carbon trickling filter

    Energy Technology Data Exchange (ETDEWEB)

    Converse, B.M.; Schroeder, E.D.; Chang, D.P.Y.

    1999-07-01

    A pilot scale trickling filter was constructed using granular activated carbon (GAC) as the packing medium and inoculated with a microbial culture known to degrade MTBE. The packing dimensions were 0.076 m in diameter and 0.22 m deep. The unit operated with recycling flow for two months before a biofilm was observed on the GAC. After two additional months the biofilm had visibly spread throughout the packing. A few pieces of GAC were placed in a sealed bottle with MTBE-contaminated water and nutrients. Headspace analysis performed over 14 days confirmed that MTBE degradation was occurring. The trickling filter was converted to continuous flow and operated for one month at a nominal flow rate of 0.1 L/min and a hydraulic loading rate of 32 m{sup 3}/m{sup 2}-d. Samples were collected for analysis at the spray nozzle and at the bottom of the trickling filter. Fractional removal varied with influent MTBE concentration, temperature and liquid flow rate. Percent MTBE removal was as high as 85%. A mechanical failure resulted in the trickling filter bed drying and percent removal dropping to less than 1 percent. However, the system recovered within five days.

  9. Methyl Jasmonate and 1-Methylcyclopropene Treatment Effects on Quinone Reductase Inducing Activity and Post-Harvest Quality of Broccoli

    Science.gov (United States)

    Ku, Kang Mo; Choi, Jeong Hee; Kim, Hyoung Seok; Kushad, Mosbah M.; Jeffery, Elizabeth H.; Juvik, John A.

    2013-01-01

    Effect of pre-harvest methyl jasmonate (MeJA) and post-harvest 1-methylcyclopropene (1-MCP) treatments on broccoli floret glucosinolate (GS) concentrations and quinone reductase (QR, an in vitro anti-cancer biomarker) inducing activity were evaluated two days prior to harvest, at harvest and at 10, 20, and 30 days of post-harvest storage at 4 °C. MeJA treatments four days prior to harvest of broccoli heads was observed to significantly increase floret ethylene biosynthesis resulting in chlorophyll catabolism during post-harvest storage and reduced product quality. Post-harvest treatment with 1-methylcyclopropene (1-MCP), which competitively binds to protein ethylene receptors, maintained post-harvest floret chlorophyll concentrations and product visual quality in both control and MeJA-treated broccoli. Transcript abundance of BoPPH, a gene which is responsible for the synthesis of pheophytinase, the primary enzyme associated with chlorophyll catabolism in broccoli, was reduced by 1-MCP treatment and showed a significant, negative correlation with floret chlorophyll concentrations. The GS, glucobrassicin, neoglucobrassicin, and gluconasturtiin were significantly increased by MeJA treatments. The products of some of the GS from endogenous myrosinase hydrolysis [sulforaphane (SF), neoascorbigen (NeoASG), N-methoxyindole-3-carbinol (NI3C), and phenethyl isothiocyanate (PEITC)] were also quantified and found to be significantly correlated with QR. Sulforaphane, the isothiocyanate hydrolysis product of the GS glucoraphanin, was found to be the most potent QR induction agent. Increased sulforaphane formation from the hydrolysis of glucoraphanin was associated with up-regulated gene expression of myrosinase (BoMyo) and the myrosinase enzyme co-factor gene, epithiospecifier modifier1 (BoESM1). This study demonstrates the combined treatment of MeJA and 1-MCP increased QR activity without post-harvest quality loss. PMID:24146962

  10. Methyl jasmonate differentially affects tocopherol content and tyrosine amino transferase activity in cultured cells of Amaranthus caudatus and Chenopodium quinoa.

    Science.gov (United States)

    Antognoni, F; Faudale, M; Poli, F; Biondi, S

    2009-03-01

    Tocopherols are lipid-soluble compounds synthesised exclusively by photosynthetic organisms. In this study, in vitro callus cultures were established from two plants that are naturally rich in tocopherols, Amaranthus caudatus and Chenopodium quinoa, in order to examine whether callus cultures were able to produce these compounds at levels comparable to those observed in planta. In both species, cotyledon explants produced the best callus induction and, once established, callus cultures were grown under two different hormonal treatments to check for effects of growth and to induce chloroplast differentiation in the cells. A rapid differentiation of chloroplasts occurred only in C. quinoa cell aggregates grown in the presence of benzyladenine, leading to the production of a homogeneous green callus. In both species, only alpha-tocopherol was produced by callus cultures, although levels were much lower than in planta, and the production was not influenced by the hormonal conditions. Interestingly, cell cultures of the two species responded in different ways to methyl jasmonate (MJ). In A. caudatus cultures, treatment with 100 mum MJ increased the production of alpha-tocopherol up to fivefold, and the inductive effect was influenced by the hormonal composition of the medium. This increase in alpha-tocopherol was associated with a proportional increase in tyrosine aminotransferase (TAT) activity, one of the key enzymes involved in tocopherol biosynthesis. By contrast, in C. quinoa cultures, elicitation with MJ did not have any effect, neither on tocopherol production, nor on TAT activity. These results are discussed in relation to chloroplast differentiation and the interplay between jasmonates and phytohormones.

  11. Design, characterisation and application of alginate-based encapsulated pig liver esterase.

    Science.gov (United States)

    Pauly, Jan; Gröger, Harald; Patel, Anant V

    2018-06-05

    Encapsulation of hydrolases in biopolymer-based hydrogels often suffers from low activities and encapsulation efficiencies along with high leaching and unsatisfactory recycling properties. Exemplified for the encapsulation of pig liver esterase the coating of alginate and chitosan beads have been studied by creating various biopolymer hydrogel beads. Enzyme activity and encapsulation efficiency were notably enhanced by chitosan coating of alginate beads while leaching remained nearly unchanged. This was caused by the enzymatic reaction acidifying the matrix, which increased enzyme retention through enhanced electrostatic enzyme-alginate interaction but decreased activity through enzyme deactivation. A practical and ready-to-use method for visualising pH in beads during reaction by co-encapsulation of a conventional pH indicator was also found. Our method proves that pH control inside the beads can only be realised by buffering. The resulting beads provided a specific activity of 0.267 μmol ∙ min -1 ∙ mg -1 , effectiveness factor 0.88, encapsulation efficiency of 88%, 5% leaching and good recycling properties. This work will contribute towards better understanding and application of encapsulated hydrolases for enzymatic syntheses. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Relationships among cell survival, O6-alkylguanine-DNA alkyltransferase activity, and reactivation of methylated adenovirus 5 and herpes simplex virus type 1 in human melanoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Maynard, K.; Parsons, P.G.; Cerny, T.; Margison, G.P. (Queensland Institute of Medical Research, Herston (Australia))

    1989-09-01

    O6-Alkylguanine-DNA alkyltransferase (ATase) activity and host cell reactivation (HCR) of 5-(3-methyl-1-triazeno)imidazole-4-carboxamide (MTIC)-methylated viruses were compared in human melanoma cell lines that were sensitive or resistant to killing by the antitumor DNA-methylating agent MTIC. Enhanced HCR of adenovirus 5 (defined as the Mer+ phenotype) generally showed a semiquantitative correlation with the natural or induced resistance of the host cells to the toxic effects of MTIC and to the level of ATase activity. However, one MTIC-resistant cell line was found (MM170) which had a low level of ATase and intermediate HCR of adenovirus. The HCR of herpes simplex virus type 1 (HSV-1) was enhanced in the Mer+ cells that had natural resistance to MTIC compared with Mer- cells. On the other hand, HCR of HSV-1 in Mer+ cells with induced resistance to MTIC was similar to that in Mer- cells. Neither adenovirus 5 nor HSV-1 infection induced ATase activity in Mer- cells. This indicates that resistance to the toxic effects of methylating agents is not invariably associated with high levels of ATase activity in human melanoma cells. Furthermore, while induction of the Mer+ phenotype from Mer- cells was usually accompanied by the recovery of ATase activity, induced Mer+ cells had less proficient repair than natural Mer+ cells, as judged quantitatively by slightly lower cellular resistance and qualitatively by deficient HCR response for HSV-1. These results suggest that the Mer- and induced Mer+ cells lack an ATase-independent DNA repair mechanism. No differences in MTIC-induced DNA repair synthesis or strand breaks were found between the Mer-, natural Mer+, and induced Mer+ phenotypes. However, UV-induced DNA repair synthesis was higher in the natural Mer+ than in the Mer- or induced Mer+ cells, both of which had increased cellular sensitivity to the antimetabolites methotrexate and hydroxyurea.

  13. Relationships among cell survival, O6-alkylguanine-DNA alkyltransferase activity, and reactivation of methylated adenovirus 5 and herpes simplex virus type 1 in human melanoma cell lines

    International Nuclear Information System (INIS)

    Maynard, K.; Parsons, P.G.; Cerny, T.; Margison, G.P.

    1989-01-01

    O6-Alkylguanine-DNA alkyltransferase (ATase) activity and host cell reactivation (HCR) of 5-(3-methyl-1-triazeno)imidazole-4-carboxamide (MTIC)-methylated viruses were compared in human melanoma cell lines that were sensitive or resistant to killing by the antitumor DNA-methylating agent MTIC. Enhanced HCR of adenovirus 5 (defined as the Mer+ phenotype) generally showed a semiquantitative correlation with the natural or induced resistance of the host cells to the toxic effects of MTIC and to the level of ATase activity. However, one MTIC-resistant cell line was found (MM170) which had a low level of ATase and intermediate HCR of adenovirus. The HCR of herpes simplex virus type 1 (HSV-1) was enhanced in the Mer+ cells that had natural resistance to MTIC compared with Mer- cells. On the other hand, HCR of HSV-1 in Mer+ cells with induced resistance to MTIC was similar to that in Mer- cells. Neither adenovirus 5 nor HSV-1 infection induced ATase activity in Mer- cells. This indicates that resistance to the toxic effects of methylating agents is not invariably associated with high levels of ATase activity in human melanoma cells. Furthermore, while induction of the Mer+ phenotype from Mer- cells was usually accompanied by the recovery of ATase activity, induced Mer+ cells had less proficient repair than natural Mer+ cells, as judged quantitatively by slightly lower cellular resistance and qualitatively by deficient HCR response for HSV-1. These results suggest that the Mer- and induced Mer+ cells lack an ATase-independent DNA repair mechanism. No differences in MTIC-induced DNA repair synthesis or strand breaks were found between the Mer-, natural Mer+, and induced Mer+ phenotypes. However, UV-induced DNA repair synthesis was higher in the natural Mer+ than in the Mer- or induced Mer+ cells, both of which had increased cellular sensitivity to the antimetabolites methotrexate and hydroxyurea

  14. Photocatalytic activity of attapulgite–BiOCl–TiO2 toward degradation of methyl orange under UV and visible light irradiation

    International Nuclear Information System (INIS)

    Zhang, Lili; Zhang, Jiahui; Zhang, Weiguang; Liu, Jianquan; Zhong, Hui; Zhao, Yijiang

    2015-01-01

    Highlights: • Excellent photocatalyst was obtained by introducing BiOCl–TiO 2 onto attapulgite. • 100 mg L −1 methyl orange (MO) was totally decomposed under UV light within 70 min. • 92.6% of 10 mg L −1 MO was decomposed within 120 min under visible light. • ATT–BiOCl–TiO 2 show better activity than P 25 especially under visible light. • Mechanism of photocatalytic activity enhancement was identified. - Abstract: An environmental friendly composite photocatalyst with efficient UV and visible light activity has been synthesized by introducing BiOCl–TiO 2 hybrid oxide onto the surface of attapulgite (ATT) (denoted as ATT–BiOCl–TiO 2 ), using a simple in situ depositing technique. The obtained products were characterized by XRD, TEM, BET and UV–vis diffuse reflectance spectra measurements. Results showed that BiOCl–TiO 2 composite particles were successfully loaded onto attapulgite fibers' surface without obvious aggregation. The photocatalytic activity of ATT–BiOCl–TiO 2 was investigated by degradation of methyl orange under UV and visible light irradiation. It was found that 100 mg L −1 methyl orange was totally decomposed under UV light within 70 min and 92.57% of 10 mg L −1 methyl orange was decomposed under visible light within 120 min using ATT–BiOCl–TiO 2 as photocatalyst. These results were quite better than that of P 25 , especially under visible light irradiation. Possible mechanism for the enhancement was proposed

  15. Fibulin-1C, C1 Esterase Inhibitor and Glucose Regulated Protein 75 Interact with the CREC Proteins, Calumenin and Reticulocalbin.

    Directory of Open Access Journals (Sweden)

    Gry Aune Westergaard Hansen

    Full Text Available Affinity purification, immunoprecipitation, gel electrophoresis and mass spectrometry were used to identify fibulin-1C, C1 esterase inhibitor and glucose regulated protein 75, grp75, as binding partners of the CREC proteins, calumenin and reticulocalbin. Surface plasmon resonance was used to verify the interaction of all three proteins with each of the CREC proteins. Fibulin-1C interacts with calumenin and reticulocalbin with an estimated dissociation constant around 50-60 nM. The interaction, at least for reticulocalbin, was not dependent upon the presence of Ca2+. C1 esterase inhibitor interacted with both proteins with an estimated dissociation constant at 1 μM for reticulocalbin and 150 nM for calumenin. The interaction, at least for calumenin, was dependent upon the presence of Ca2+ with strong interaction at 3.5 mM while no detectable interaction could be found at 0.1 mM. Grp75 binds with an affinity of approximately 3-7 nM with reticulocalbin as well as with calumenin. These interactions suggest functional participation of the CREC proteins in chaperone activity, cell proliferation and transformation, cellular aging, haemostasis and thrombosis as well as modulation of the complement system in fighting bacterial infection.

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

    Directory of Open Access Journals (Sweden)

    Hampus Sunner

    2015-09-01

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

  17. Study of the role of β-adrenoceptors in the mechanisms of hemodynamic action and radioprotective activity of 2-methyl-5-vinylpyridine copolymer with 2-methyl-5-vinylpyridinium-N-oxide

    International Nuclear Information System (INIS)

    Korovkina, Eh.P.; Mikhajlov, P.P.; Tsorin, I.B.

    2000-01-01

    The effect of the new water soluble copolymer 2-methyl-5-vinylpyridine with 2-methyl-5-vinylpyridinium-N-oxide on the arterial pressure in dogs and cats is studied; the possibility of modifying the polymer hemodynamical activity under the impact of the β-propranolol blocking is investigated; the effect of the latter one on the copolymer in dogs is evaluated. The therapeutic antiradiation efficiency of the copolymer was judged by the irradiated dogs survival during 45 days. The dogs were subjected to the 137 Cs γ-radiation impact with the dose rate of 153 cGy in the 330 cGy. It is shown that the copolymer causes depression reaction in the anesthetized dogs and cats characteristic for the β-adrenomimetics This effect is leveled by the nonselective β-adrenoblocking - propranolol. The preliminary introduction of propranolol in dogs decreased the therapeutic antiradiation-efficiency of the given copolymer from 68.4 up to 8.3 % [ru

  18. Telomerase activity, telomere length and hTERT DNA methylation in peripheral blood mononuclear cells from monozygotic twins with discordant smoking habits.

    Science.gov (United States)

    Marcon, Francesca; Siniscalchi, Ester; Andreoli, Cristina; Allione, Alessandra; Fiorito, Giovanni; Medda, Emanuela; Guarrera, Simonetta; Matullo, Giuseppe; Crebelli, Riccardo

    2017-10-01

    Increased telomerase expression has been implicated in the pathogenesis of lung cancer and, since the primary cause of lung cancer is smoking, an association between telomerase reactivation and tobacco smoke has been proposed. In this work an investigation has been performed to assess the relationship between tobacco smoke exposure and telomerase activity (TA) in peripheral blood mononuclear cells of healthy smokers. The methylation status of the catalytic subunit of telomerase hTERT was concurrently investigated to assess the possible association between epigenetic modifications of hTERT and TA. Besides, the association between smoke and telomere length (TL) has been evaluated. Healthy monozygotic twins with discordant smoking habits were selected as study population to minimize inter-individual differences because of demographic characteristics and genetic heterogeneity. Statistically significant higher values of TA and TL were observed in smokers compared to nonsmoker co-twins. The multivariate analysis of data showed, besides smoking habits (P = 0.02), an influence of gender (P = 0.006) and BMI (P = 0.001) on TA and a borderline effect of gender (P = 0.05) on TL. DNA methylation analysis, focused on 100 CpG sites mapping in hTERT, highlighted nine CpG sites differentially methylated in smokers. When co-twins were contrasted, selecting as variables the intra-twin difference in TA and hTERT DNA methylation, a statistically significant inverse correlation (P = 0.003) was observed between TA and DNA methylation at the cg05521538 site. In conclusion, these results indicate an association of tobacco smoke with TA and TL and suggest a possible association between smoke-induced epigenetic effects and TA in healthy smokers. Environ. Mol. Mutagen. 58:551-559, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. Simultaneous measurement of two enzyme activities using infrared spectroscopy: A comparative evaluation of PARAFAC, TUCKER and N-PLS modeling.

    Science.gov (United States)

    Baum, Andreas; Hansen, Per Waaben; Meyer, Anne S; Mikkelsen, Jørn Dalgaard

    2013-08-06

    Enzymes are used in many processes to release fermentable sugars for green production of biofuel, or the refinery of biomass for extraction of functional food ingredients such as pectin or prebiotic oligosaccharides. The complex biomasses may, however, require a multitude of specific enzymes which are active on specific substrates generating a multitude of products. In this paper we use the plant polymer, pectin, to present a method to quantify enzyme activity of two pectolytic enzymes by monitoring their superimposed spectral evolutions simultaneously. The data is analyzed by three chemometric multiway methods, namely PARAFAC, TUCKER3 and N-PLS, to establish simultaneous enzyme activity assays for pectin lyase and pectin methyl esterase. Correlation coefficients Rpred(2) for prediction test sets are 0.48, 0.96 and 0.96 for pectin lyase and 0.70, 0.89 and 0.89 for pectin methyl esterase, respectively. The retrieved models are compared and prediction test sets show that especially TUCKER3 performs well, even in comparison to the supervised regression method N-PLS. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Fumigant Activity of 6 Selected Essential Oil Compounds and Combined Effect of Methyl Salicylate And Trans-Cinnamaldehyde Against Culex pipiens pallens.

    Science.gov (United States)

    Ma, Wei-Bin; Feng, Jun-Tao; Jiang, Zhi-Li; Zhang, Xing

    2014-09-01

    We studied the knockdown activity and lethal toxicity of 6 essential oil compounds-methyl salicylate, linalool, 2-phenethyl alcohol, eugenol, β-citronellol, and trans-cinnamaldehyde-as fumigants against adult female Culex pipiens pallens in the laboratory. Of the 6 products tested, trans-cinnamaldehyde was the most toxic (LC50  =  0.26 µl/l air, 24 h) with a slow knockdown time (KT95  =  176.5 min at 0.5 µl/l air). Methyl salicylate displayed a lower toxicity (LC50  =  1.17 µl/l air, 24 h) but the fastest knockdown activity (KT95  =  16.8 min) at the sublethal concentration 0.5 µl/l air. Furthermore, the binary mixture of methyl salicylate and trans-cinnamaldehyde exhibited a combined effect of fast knockdown activity and high toxicity against Cx. p. pallens adults, showing potential for development as natural fumigants for mosquito control.

  1. The antifungal activity of the cuticular and internal fatty acid methyl esters and alcohols in Calliphora vomitoria.

    Science.gov (United States)

    Gołębiowski, Marek; Cerkowniak, Magdalena; Dawgul, Małgorzata; Kamysz, Wojciech; Boguś, Mieczysława I; Stepnowski, Piotr

    2013-07-01

    SUMMARY The composition of the fatty acid methyl ester (FAME) and alcohol fractions of the cuticular and internal lipids of Calliphora vomitoria larvae, pupae and male/female adults was obtained by separating these two fractions by HPLC-LLSD and analysing them quantitatively using GC-MS. Analysis of the cuticular lipids of the worldwide, medically important ectoparasite C. vomitoria revealed 6 FAMEs with odd-numbered carbon chains from C15:0 to C19:0 in the larvae, while internal lipids contained 9 FAMEs ranging from C15:1 to C19:0. Seven FAMEs from C15:0 to C19:0 were identified in the cuticular lipids of the pupae, whereas the internal lipids of the pupae contained 10 FAMEs from C13:0 to C19:0. The cuticular lipids of males and females and also the internal lipids of males contained 5, 7 and 6 FAMEs from C15:0 to C19:0 respectively. Seven FAMEs from C13:0 to C19:0 were identified in the internal lipids of females, and 7, 6, 5 and 3 alcohols were found in the cuticular lipids of larvae, pupae, males and females respectively. Only saturated alcohols with even-numbered carbon chains were present in these lipids. Only 1 alcohol (C22:0) was detected in the internal lipids of C. vomitoria larvae, while just 4 alcohols from - C18:0 to C24:0 - were identified in the internal lipids of pupae, and males and females. We also identified glycerol and cholesterol in the larvae, pupae, males and females of C. vomitoria. The individual alcohols and FAMEs, as well as their mixtures isolated from the cuticular and internal lipids of larvae, pupae, males and females of C. vomitoria, demonstrated antimicrobial activity against entomopathogenic fungi.

  2. Rate Constants and Activation Energies for Gas-Phase Reactions of Three Cyclic Volatile Methyl Siloxanes with the Hydroxyl Radical.

    Science.gov (United States)

    Safron, Andreas; Strandell, Michael; Kierkegaard, Amelie; Macleod, Matthew

    2015-07-01

    Reaction with hydroxyl radicals (OH) is the major pathway for removal of cyclic volatile methyl siloxanes (cVMS) from air. We present new measurements of second-order rate constants for reactions of the cVMS octamethylcyclotetrasiloxane (D 4 ), decamethylcyclopentasiloxane (D 5 ), and dodecamethylcyclohexasiloxane (D 6 ) with OH determined at temperatures between 313 and 353 K. Our measurements were made using the method of relative rates with cyclohexane as a reference substance and were conducted in a 140-mL gas-phase reaction chamber with online mass spectrometry analysis. When extrapolated to 298 K, our measured reaction rate constants of D 4 and D 5 with the OH radical are 1.9 × 10 -12 (95% confidence interval (CI): (1.7-2.2) × 10 -12 ) and 2.6 × 10 -12 (CI: (2.3-2.9) × 10 -12 ) cm 3 molecule -1 s -1 , respectively, which are 1.9× and 1.7× faster than previous measurements. Our measured rate constant for D 6 is 2.8 × 10 -12 (CI: (2.5-3.2) × 10 -12 ) cm 3 molecule -1 s -1 and to our knowledge there are no comparable laboratory measurements in the literature. Reaction rates for D 5 were 33% higher than for D 4 (CI: 30-37%), whereas the rates for D 6 were only 8% higher than for D 5 (CI: 5-10%). The activation energies of the reactions of D 4 , D 5 , and D 6 with OH were not statistically different and had a value of 4300 ± 2800 J/mol.

  3. Rate Constants and Activation Energies for Gas‐Phase Reactions of Three Cyclic Volatile Methyl Siloxanes with the Hydroxyl Radical

    Science.gov (United States)

    Safron, Andreas; Strandell, Michael; Kierkegaard, Amelie

    2015-01-01

    ABSTRACT Reaction with hydroxyl radicals (OH) is the major pathway for removal of cyclic volatile methyl siloxanes (cVMS) from air. We present new measurements of second‐order rate constants for reactions of the cVMS octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) with OH determined at temperatures between 313 and 353 K. Our measurements were made using the method of relative rates with cyclohexane as a reference substance and were conducted in a 140‐mL gas‐phase reaction chamber with online mass spectrometry analysis. When extrapolated to 298 K, our measured reaction rate constants of D4 and D5 with the OH radical are 1.9 × 10−12 (95% confidence interval (CI): (1.7–2.2) × 10−12) and 2.6 × 10−12 (CI: (2.3–2.9) × 10−12) cm3 molecule−1 s−1, respectively, which are 1.9× and 1.7× faster than previous measurements. Our measured rate constant for D6 is 2.8 × 10−12 (CI: (2.5–3.2) × 10−12) cm3 molecule−1 s−1 and to our knowledge there are no comparable laboratory measurements in the literature. Reaction rates for D5 were 33% higher than for D4 (CI: 30–37%), whereas the rates for D6 were only 8% higher than for D5 (CI: 5–10%). The activation energies of the reactions of D4, D5, and D6 with OH were not statistically different and had a value of 4300 ± 2800 J/mol. PMID:27708500

  4. Molecular Cloning and Characterization of a Newly Isolated Pyrethroid-Degrading Esterase Gene from a Genomic Library of Ochrobactrum anthropi YZ-1

    Science.gov (United States)

    Song, Jinlong; Shi, Yanhua; Li, Kang; Zhao, Bin; Yan, Yanchun

    2013-01-01

    A novel pyrethroid-degrading esterase gene pytY was isolated from the genomic library of Ochrobactrum anthropi YZ-1. It possesses an open reading frame (ORF) of 897 bp. Blast search showed that its deduced amino acid sequence shares moderate identities (30% to 46%) with most homologous esterases. Phylogenetic analysis revealed that PytY is a member of the esterase VI family. pytY showed very low sequence similarity compared with reported pyrethroid-degrading genes. PytY was expressed, purified, and characterized. Enzyme assay revealed that PytY is a broad-spectrum degrading enzyme that can degrade various pyrethroids. It is a new pyrethroid-degrading gene and enriches genetic resource. Kinetic constants of Km and Vmax were 2.34 mmol·L−1 and 56.33 nmol min−1, respectively, with lambda-cyhalothrin as substrate. PytY displayed good degrading ability and stability over a broad range of temperature and pH. The optimal temperature and pH were of 35°C and 7.5. No cofactors were required for enzyme activity. The results highlighted the potential use of PytY in the elimination of pyrethroid residuals from contaminated environments. PMID:24155944

  5. Structural analysis of thermostabilizing mutations of cocaine esterase

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, Diwahar; Nance, Mark R.; Gao, Daquan; Ko, Mei-Chuan; Macdonald, Joanne; Tamburi, Patricia; Yoon, Dan; Landry, Donald M.; Woods, James H.; Zhan, Chang-Guo; Tesmer, John J.G.; Sunahara, Roger K. (Michigan); (Columbia); (Kentucky)

    2010-09-03

    Cocaine is considered to be the most addictive of all substances of abuse and mediates its effects by inhibiting monoamine transporters, primarily the dopamine transporters. There are currently no small molecules that can be used to combat its toxic and addictive properties, in part because of the difficulty of developing compounds that inhibit cocaine binding without having intrinsic effects on dopamine transport. Most of the effective cocaine inhibitors also display addictive properties. We have recently reported the use of cocaine esterase (CocE) to accelerate the removal of systemic cocaine and to prevent cocaine-induced lethality. However, wild-type CocE is relatively unstable at physiological temperatures ({tau}{sub 1/2} {approx} 13 min at 37 C), presenting challenges for its development as a viable therapeutic agent. We applied computational approaches to predict mutations to stabilize CocE and showed that several of these have increased stability both in vitro and in vivo, with the most efficacious mutant (T172R/G173Q) extending half-life up to 370 min. Here we present novel X-ray crystallographic data on these mutants that provide a plausible model for the observed enhanced stability. We also more extensively characterize the previously reported variants and report on a new stabilizing mutant, L169K. The improved stability of these engineered CocE enzymes will have a profound influence on the use of this protein to combat cocaine-induced toxicity and addiction in humans.

  6. Expression and characterization of a new esterase with GCSAG motif from a permafrost metagenomic library.

    Science.gov (United States)

    Petrovskaya, Lada E; Novototskaya-Vlasova, Ksenia A; Spirina, Elena V; Durdenko, Ekaterina V; Lomakina, Galina Yu; Zavialova, Maria G; Nikolaev, Evgeny N; Rivkina, Elizaveta M

    2016-05-01

    As a result of construction and screening of a metagenomic library prepared from a permafrost-derived microcosm, we have isolated a novel gene coding for a putative lipolytic enzyme that belongs to the hormone-sensitive lipase family. It encodes a polypeptide of 343 amino acid residues whose amino acid sequence displays maximum likelihood with uncharacterized proteins from Sphingomonas species. A putative catalytic serine residue of PMGL2 resides in a new variant of a recently discovered GTSAG sequence in which a Thr residue is replaced by a Cys residue (GCSAG). The recombinant PMGL2 was produced in Escherichia coli cells and purified by Ni-affinity chromatography. The resulting protein preferably utilizes short-chain p-nitrophenyl esters (C4 and C8) and therefore is an esterase. It possesses maximum activity at 45°C in slightly alkaline conditions and has limited thermostability at higher temperatures. Activity of PMGL2 is stimulated in the presence of 0.25-1.5 M NaCl indicating the good salt tolerance of the new enzyme. Mass spectrometric analysis demonstrated that N-terminal methionine in PMGL2 is processed and cysteine residues do not form a disulfide bond. The results of the study demonstrate the significance of the permafrost environment as a unique genetic reservoir and its potential for metagenomic exploration. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Sp1/Sp3 and DNA-methylation contribute to basal transcriptional activation of human podoplanin in MG63 versus Saos-2 osteoblastic cells

    Directory of Open Access Journals (Sweden)

    Puri Christina

    2007-03-01

    Full Text Available Abstract Background Podoplanin is a membrane mucin that, among a series of tissues, is expressed on late osteoblasts and osteocytes. Since recent findings have focussed on podoplanin's potential role as a tumour progression factor, we aimed at identifying regulatory elements conferring PDPN promoter activity. Here, we characterized the molecular mechanism controlling basal PDPN transcription in human osteoblast-like MG63 versus Saos-2 cells. Results We cloned and sequenced 2056 nucleotides from the 5'-flanking region of the PDPN gene and a computational search revealed that the TATA and CAAT box-lacking promoter possesses features of a growth-related gene, such as a GC-rich 5' region and the presence of multiple putative Sp1, AP-4 and NF-1 sites. Reporter gene assays demonstrated a functional promoter in MG63 cells exhibiting 30-fold more activity than in Saos-2 cells. In vitro DNase I footprinting revealed eight protected regions flanked by DNaseI hypersensitive sites within the region bp -728 to -39 present in MG63, but not in Saos-2 cells. Among these regions, mutation and supershift electrophoretic mobility shift assays (EMSA identified four Sp1/Sp3 binding sites and two binding sites for yet unknown transcription factors. Deletion studies demonstrated the functional importance of two Sp1/Sp3 sites for PDPN promoter activity. Overexpression of Sp1 and Sp3 independently increased the stimulatory effect of the promoter and podoplanin mRNA levels in MG63 and Saos-2 cells. In SL2 cells, Sp3 functioned as a repressor, while Sp1 and Sp3 acted positively synergistic. Weak PDPN promoter activity of Saos-2 cells correlated with low Sp1/Sp3 nuclear levels, which was confirmed by Sp1/Sp3 chromatin immunoprecipitations in vivo. Moreover, methylation-sensitive Southern blot analyses and bisulfite sequencing detected strong methylation of CpG sites upstream of bp -464 in MG63 cells, but hypomethylation of these sites in Saos-2 cells. Concomitantly

  8. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

    Energy Technology Data Exchange (ETDEWEB)

    Domanska, Urszula [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)], E-mail: ula@ch.pw.edu.pl; Marciniak, Andrzej [Physical Chemistry Department, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland)

    2009-12-15

    The activity coefficients at infinite dilution, {gamma}{sub 13}{sup {infinity}} for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf{sub 2}] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values {delta}H{sub 1}{sup E,{infinity}} were calculated from the experimental {gamma}{sub 13}{sup {infinity}} values obtained over the temperature range. The selectivity for different separation problems were calculated from the {gamma}{sub 13}{sup {infinity}} and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

  9. Activity coefficients at infinite dilution measurements for organic solutes and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide

    International Nuclear Information System (INIS)

    Domanska, Urszula; Marciniak, Andrzej

    2009-01-01

    The activity coefficients at infinite dilution, γ 13 ∞ for 36 solutes: alkanes, cycloalkanes, alkenes, alkynes, aromatic hydrocarbons, alcohols, thiophene, tetrahydrofuran, ethers, acetone, and water in the ionic liquid 4-methyl-N-butyl-pyridinium bis(trifluoromethylsulfonyl)-imide [bmPY][NTf 2 ] were determined by gas-liquid chromatography at temperatures from 298.15 K to 368.15 K. The partial molar excess enthalpies at infinite dilution values ΔH 1 E,∞ were calculated from the experimental γ 13 ∞ values obtained over the temperature range. The selectivity for different separation problems were calculated from the γ 13 ∞ and compared to the literature values for other ionic liquids, N-methyl-2-pyrrolidinone (NMP) and sulfolane.

  10. Pyrrolidon carboxypeptidase activities in the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-ovary axes of rats with mammary gland cancer induced by N-methyl nitrosourea.

    Science.gov (United States)

    Carrera, M P; Ramírez-Expósito, M J; Valenzuela, M T; García, M J; Mayas, M D; Arias de Saavedra, J M; Sánchez, R; Pérez, M C; Martínez-Martos, J M

    2005-02-01

    Pyrrolidon carboxypeptidase is an omega-peptidase that hydrolyses N-terminal pyroglutamyl residues from biologically active peptides such as gonadotropin-releasing and thyrotrophin-releasing hormones. We previously described a decrease in both rat and human pyrrolidon carboxypeptidase activity with breast cancer, suggesting that gonadotropin-releasing hormone may be an important local intracrine, autocrine and/or paracrine hormonal factor in the pathogenesis of breast cancer while playing a role in the tumoral process. However, the other susceptible substrate of pyrrolidon carboxypeptidase, thyrotrophin-releasing hormone, may also be modified with breast cancer, supporting an association between breast cancer and thyroid disorders. The present work analyses soluble and membrane-bound pyrrolidon carboxypeptidase activities in the hypothalamus-pituitary-thyroid and hypothalamus-pituitary-ovary axes in N-methyl nitrosourea-induced breast cancer in rats. Our aim was to determine the possible relationship between gonadotropin-releasing hormone and thyrotrophin-releasing hormone regulation through pyrrolidon carboxypeptidase activity. We propose that pyrrolidon carboxypeptidase activity dysregulation at various local and systemic levels may participate in the initiation, promotion and progression of breast cancer induced in rat by N-methyl nitrosourea through the increase in gonadotropin-releasing hormone. Since pyrrolidon carboxypeptidase activity also acts on thyrotrophin-releasing hormone, the dysregulation of this enzyme's activity could indirectly affect hypothalamus-pituitary-thyroid axis function, and thus potentially represent a link between the diseases of thyroid and breast cancer.

  11. Artificial neural network and particle swarm optimization for removal of methyl orange by gold nanoparticles loaded on activated carbon and Tamarisk

    Science.gov (United States)

    Ghaedi, M.; Ghaedi, A. M.; Ansari, A.; Mohammadi, F.; Vafaei, A.

    2014-11-01

    The influence of variables, namely initial dye concentration, adsorbent dosage (g), stirrer speed (rpm) and contact time (min) on the removal of methyl orange (MO) by gold nanoparticles loaded on activated carbon (Au-NP-AC) and Tamarisk were investigated using multiple linear regression (MLR) and artificial neural network (ANN) and the variables were optimized by partial swarm optimization (PSO). Comparison of the results achieved using proposed models, showed the ANN model was better than the MLR model for prediction of methyl orange removal using Au-NP-AC and Tamarisk. Using the optimal ANN model the coefficient of determination (R2) for the test data set were 0.958 and 0.989; mean squared error (MSE) values were 0.00082 and 0.0006 for Au-NP-AC and Tamarisk adsorbent, respectively. In this study a novel and green approach were reported for the synthesis of gold nanoparticle and activated carbon by Tamarisk. This material was characterized using different techniques such as SEM, TEM, XRD and BET. The usability of Au-NP-AC and activated carbon (AC) Tamarisk for the methyl orange from aqueous solutions was investigated. The effect of variables such as pH, initial dye concentration, adsorbent dosage (g) and contact time (min) on methyl orange removal were studied. Fitting the experimental equilibrium data to various isotherm models such as Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich models show the suitability and applicability of the Langmuir model. Kinetic models such as pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models indicate that the second-order equation and intraparticle diffusion models control the kinetic of the adsorption process. The small amount of proposed Au-NP-AC and activated carbon (0.015 g and 0.75 g) is applicable for successful removal of methyl orange (>98%) in short time (20 min for Au-NP-AC and 45 min for Tamarisk-AC) with high adsorption capacity 161 mg g-1 for Au-NP-AC and 3.84 mg g-1 for Tamarisk-AC.

  12. Avoidance behaviour response and esterase inhibition in the earthworm, Lumbricus terrestris, after exposure to chlorpyrifos.

    Science.gov (United States)

    Martínez Morcillo, S; Yela, J L; Capowiez, Y; Mazzia, C; Rault, M; Sanchez-Hernandez, Juan C

    2013-05-01

    The avoidance response of earthworms to polluted soils has been standardised using a simple and low-cost test, which facilitates soil toxicity screening. In this study, the avoidance response of Lumbricus terrestris was quantified in chlorpyrifos-spiked soils, depending on the pesticide concentration and exposure duration. The inhibition of acetylcholinesterase (AChE) and carboxylesterase (CbE) activities was also determined as indirect measures of pesticide bioavailability. The effects of different chlorpyrifos concentrations were examined in a standardised test (two-chamber system) with 0.6, 3 and 15 mg/kg chlorpyrifos. A modification of the test involved a pre-exposure step (24, 48 or 72 h) in soils spiked with 15 mg/kg. In both protocols, earthworms were unable to avoid the contaminated soils. However, the esterase activities showed that all earthworms were exposed to chlorpyrifos. Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test (0.58 ± 0.20 U/mg protein, mean ± SD; n = 72), whereas the CbE activity was significantly inhibited (62-87 % inhibition) in earthworms exposed to 3 and 15 mg/kg. In the modified test, earthworms had greatly inhibited AChE activity (0.088 ± 0.034 U/mg protein, n = 72), which was supported by reactivation of the inhibited enzyme activity in the presence of pralidoxime (2-PAM). Similarly, the CbE activity was significantly inhibited in earthworms with all treatments. This study suggests that the avoidance behaviour test for organophosphorus-contaminated soils could be supported by specific biomarkers to facilitate a better understanding of pesticide exposure and toxicity during this test.

  13. Synthesis and Antitumor Activity of 3-Methyl-4-oxo-3,4-dihydroimidazo [5,1-d][1,2,3,5]tetrazine-8-carboxylates and -carboxamides

    Directory of Open Access Journals (Sweden)

    Lin-Xiang Zhao

    2010-12-01

    Full Text Available Seventeen novel 3-methyl-4-oxo-3,4-dihydroimidazo[5,1-d][1,2,3,5]tetrazine-8-carboxylate and -carboxamide derivatives were synthesized and evaluated for their growth inhibition in seven human solid tumor and a human leukemia HL-60 cell lines. Compound IVa showed more activity than the other compounds and the positive control temozolomide. In the presence of 40 mg/mL of IVa, the survival rate of all tested tumor cells was less than 10%. Esters displayed more potent antitumour activity than amides and temozolomide against HL-60 cells. These compounds also exhibited considerably enhanced water-solubility.

  14. Histone Lysine Methylation and Neurodevelopmental Disorders

    Directory of Open Access Journals (Sweden)

    Jeong-Hoon Kim

    2017-06-01

    Full Text Available Methylation of several lysine residues of histones is a crucial mechanism for relatively long-term regulation of genomic activity. Recent molecular biological studies have demonstrated that the function of histone methylation is more diverse and complex than previously thought. Moreover, studies using newly available genomics techniques, such as exome sequencing, have identified an increasing number of histone lysine methylation-related genes as intellectual disability-associated genes, which highlights the importance of accurate control of histone methylation during neurogenesis. However, given the functional diversity and complexity of histone methylation within the cell, the study of the molecular basis of histone methylation-related neurodevelopmental disorders is currently still in its infancy. Here, we review the latest studies that revealed the pathological implications of alterations in histone methylation status in the context of various neurodevelopmental disorders and propose possible therapeutic application of epigenetic compounds regulating histone methylation status for the treatment of these diseases.

  15. SH groups in the alpha-naphthyl acetate esterase in the thyroid of the guinea-pig. A histochemical study

    DEFF Research Database (Denmark)

    Kirkeby, S

    1976-01-01

    ] are added to the incubation media. Thus the inhibition is by far the greatest in group I cells, which also show the greatest activity after incubation in conventional media, when long fixation and storage times are used. In all cases the inhibiting effect was complete or almost completely reversed......The alpha-naphthyl acetate esterase in both group I and group II thyroid cells is shown to contain SH groups since there is a decline in activity in both cell groups when certain sulfhydryl reagents [DTNB; 5,5'-Dithiobis-(2-nitrobenzoic acid)-AgNO3-Mersalyl-PCMB (parachloro mercuribenzoate) + urea...... if cysteine was added to the incubation media in equivalent concentrations to the SH blocker. There were great differences among the sulfhydryl reagents used in their ability to bring about enzyme inhibition. The alkylating agents NEM (N-ethylmaleimide) and iodoacetamide had no or little effect while PCMB...

  16. Interactive toxicity of chlorpyrifos and parathion in neonatal rats: Role of esterases in exposure sequence-dependent toxicity

    International Nuclear Information System (INIS)

    Kacham, R.; Karanth, S.; Baireddy, P.; Liu, J.; Pope, C.

    2006-01-01

    We previously reported that sequence of exposure to chlorpyrifos and parathion in adult rats can markedly influence toxic outcome. In the present study, we evaluated the interactive toxicity of chlorpyrifos (8 mg/kg, po) and parathion (0.5 mg/kg, po) in neonatal (7 days old) rats. Rats were exposed to the insecticides either concurrently or sequentially (separated by 4 h) and sacrificed at 4, 8, and 24 h after the first exposure for biochemical measurements (cholinesterase activity in brain, plasma, and diaphragm and carboxylesterase activity in plasma and liver). The concurrently-exposed group showed more cumulative lethality (15/24) than either of the sequential dosing groups. With sequential dosing, rats treated initially with chlorpyrifos prior to parathion (C/P) exhibited higher lethality (7/23) compared to those treated with parathion before chlorpyrifos (P/C; 1/24). At 8 h after initial dosing, brain cholinesterase inhibition was significantly greater in the C/P group (59%) compared to the P/C group (28%). Diaphragm and plasma cholinesterase activity also followed a relatively similar pattern of inhibition. Carboxylesterase inhibition in plasma and liver was relatively similar among the treatment groups across time-points. Similar sequence-dependent differences in brain cholinesterase inhibition were also noted with lower binary exposures to chlorpyrifos (2 mg/kg) and parathion (0.35 mg/kg). In vitro and ex vivo studies compared relative oxon detoxification of carboxylesterases (calcium-insensitive) and A-esterases (calcium-sensitive) in liver homogenates from untreated and insecticide pretreated rats. Using tissues from untreated rats, carboxylesterases detoxified both chlorpyrifos oxon and paraoxon, while A-esterases only detoxified chlorpyrifos oxon. With parathion pretreatment, A-esterases still detoxified chlorpyrifos oxon while liver from chlorpyrifos pretreated rats had little apparent effect on paraoxon. We conclude that while neonatal rats are less

  17. Comparative evaluation of lignocellulolytic activities of filamentous cultures of monocentric and polycentric anaerobic fungi.

    Science.gov (United States)

    Dagar, Sumit Singh; Kumar, Sanjay; Mudgil, Priti; Puniya, Anil Kumar

    2018-04-01

    Sixteen strains of monocentric and polycentric anaerobic fungi were evaluated for cellulase, xylanase and esterase activities. Though strain level variations were observed among all genera, Neocallimastix and Orpinomyces strains exhibited the highest lignocellulolytic activities. The esterase activities of monocentric group of anaerobic fungi were better than the polycentric group. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. The role of low levels of juvenile hormone Esterase in the metamorphosis of Manduca sexta

    Directory of Open Access Journals (Sweden)

    M.H. Browder

    2001-10-01

    Full Text Available The activity of juvenile hormone esterase (JHE in feeding fifth instar larvae of Manduca sexta increases gradually with larval weight and rises to a peak after larvae pass the critical weight when juvenile hormone secretion ceases. Starvation of larvae of Manduca sexta (L. that had exceeded the critical weight inhibited peak levels of JHE, but did not delay entry into the wandering stage when larvae leave the plant in search of a pupation site. This suggests that peak levels of JHE may not be essential for the normal timing of metamorphosis. Starved larvae pupated normally, indicating the peak of JHE was not necessary for a morphologically normal pupation. Treatments of larvae with the selective JHE inhibitor O-ethyl-S-phenyl phosphoramidothiolate (EPPAT that began immediately after larvae achieved the critical weight (6.0 to 6.5 grams for our strain of Manduca delayed entry into the wandering stage. By contrast, EPPAT treatment of larvae at weights above 8.0g had no effect on the subsequent timing of the onset of wandering. Therefore, although the normal timing of the onset of wandering does not require peak levels of JHE, it requires low to moderate levels of JHE to be present until larvae reach a weight of about 8.0g.

  19. Subunit Stabilization and Polyethylene Glycolation of Cocaine Esterase Improves In Vivo Residence Time

    Energy Technology Data Exchange (ETDEWEB)

    Narasimhan, Diwahar; Collins, Gregory T.; Nance, Mark R.; Nichols, Joseph; Edwald, Elin; Chan, Jimmy; Ko, Mei-Chuan; Woods, James H.; Tesmer, John J.G.; Sunahara, Roger K. (Michigan)

    2012-03-15

    No small-molecule therapeutic is available to treat cocaine addiction, but enzyme-based therapy to accelerate cocaine hydrolysis in serum has gained momentum. Bacterial cocaine esterase (CocE) is the fastest known native enzyme that hydrolyzes cocaine. However, its lability at 37 C has limited its therapeutic potential. Cross-linking subunits through disulfide bridging is commonly used to stabilize multimeric enzymes. Herein we use structural methods to guide the introduction of two cysteine residues within dimer interface of CocE to facilitate intermolecular disulfide bond formation. The disulfide-crosslinked enzyme displays improved thermostability, particularly when combined with previously described mutations that enhance stability (T172R-G173Q). The newly modified enzyme yielded an extremely stable form of CocE (CCRQ-CocE) that retained greater than 90% of its activity after 41 days at 37 C, representing an improvement of more than 4700-fold over the wild-type enzyme. CCRQ-CocE could also be modified by polyethylene glycol (PEG) polymers, which improved its in vivo residence time from 24 to 72 h, as measured by a cocaine lethality assay, by self-administration in rodents, and by measurement of inhibition of cocaine-induced cardiovascular effects in rhesus monkeys. PEG-CCRQ elicited negligible immune response in rodents. Subunit stabilization and PEGylation has thus produced a potential protein therapeutic with markedly higher stability both in vitro and in vivo.

  20. Separating esterase targets of organophosphorus compounds in the brain by preparative chromatography.

    Science.gov (United States)

    Mangas, I; Vilanova, E; Benabent, M; Estévez, J

    2014-02-10

    Low level exposure to organophosphorus esters (OPs) may cause long-term neurological effects and affect specific cognition domains in experimental animals and humans. Action on known targets cannot explain most of these effects by. Soluble carboxylesterases (EC 3.1.1.1) of chicken brain have been kinetically discriminated using paraoxon, mipafox and phenylmethyl sulfonylfluoride as inhibitors and phenyl valerate as a substrate. Three different enzymatic components were discriminated and called Eα, Eβ and Eγ. In this work, a fractionation procedure with various steps was developed using protein native separation methods by preparative HPLC. Gel permeation chromatography followed by ion exchange chromatography allowed enriched fractions with different kinetic behaviors. The soluble chicken brain fraction was fractionated, while total esterase activity, proteins and enzymatic components Eα, Eβ and Eγ were monitored in each subfraction. After the analysis, 13 fractions were pooled and conserved. Preincubation of the soluble chicken brain fraction of with the organophosphorus mipafox gave rise to a major change in the ion exchange chromatography profile, but not in the molecular exchanged chromatography profile, which suggest that mipafox permanently modifies the ionic properties of numerous proteins. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Construction of an Immobilized Thermophilic Esterase on Epoxy Support for Poly(ε-caprolactone Synthesis

    Directory of Open Access Journals (Sweden)

    Hui Ren

    2016-06-01

    Full Text Available Developing an efficient immobilized enzyme is of great significance for improving the operational stability of enzymes in poly(ε-caprolactone synthesis. In this paper, a thermophilic esterase AFEST from the archaeon Archaeoglobus fulgidus was successfully immobilized on the epoxy support Sepabeads EC-EP via covalent attachment, and the immobilized enzyme was then employed as a biocatalyst for poly(ε-caprolactone synthesis. The enzyme loading and recovered activity of immobilized enzyme was measured to be 72 mg/g and 10.4 U/mg using p-nitrophenyl caprylate as the substrate at 80 °C, respectively. Through the optimization of reaction conditions (enzyme concentration, temperature, reaction time and medium, poly(ε-caprolactone was obtained with 100% monomer conversion and low number-average molecular weight (Mn < 1300 g/mol. Further, the immobilized enzyme exhibited excellent reusability, with monomer conversion values exceeding 75% during 15 batch reactions. Finally, poly(ε-caprolactone was enzymatically synthesized with an isolated yield of 75% and Mn value of 3005 g/mol in a gram-scale reaction.

  2. Construction of an Immobilized Thermophilic Esterase on Epoxy Support for Poly(ε-caprolactone) Synthesis.

    Science.gov (United States)

    Ren, Hui; Xing, Zhen; Yang, Jiebing; Jiang, Wei; Zhang, Gang; Tang, Jun; Li, Quanshun

    2016-06-18

    Developing an efficient immobilized enzyme is of great significance for improving the operational stability of enzymes in poly(ε-caprolactone) synthesis. In this paper, a thermophilic esterase AFEST from the archaeon Archaeoglobus fulgidus was successfully immobilized on the epoxy support Sepabeads EC-EP via covalent attachment, and the immobilized enzyme was then employed as a biocatalyst for poly(ε-caprolactone) synthesis. The enzyme loading and recovered activity of immobilized enzyme was measured to be 72 mg/g and 10.4 U/mg using p-nitrophenyl caprylate as the substrate at 80 °C, respectively. Through the optimization of reaction conditions (enzyme concentration, temperature, reaction time and medium), poly(ε-caprolactone) was obtained with 100% monomer conversion and low number-average molecular weight (Mn enzyme exhibited excellent reusability, with monomer conversion values exceeding 75% during 15 batch reactions. Finally, poly(ε-caprolactone) was enzymatically synthesized with an isolated yield of 75% and Mn value of 3005 g/mol in a gram-scale reaction.

  3. Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae): impact of developmental stage, sex, and organophosphorus in vitro exposure.

    Science.gov (United States)

    Basso, Agustín; Attademo, Andrés M; Lajmanovich, Rafael C; Peltzer, Paola M; Junges, Celina; Cabagna, Mariana C; Fiorenza, Gabriela S; Sanchez-Hernandez, Juan Carlos

    2012-01-01

    In this study, we determined normal serum butyrylcholinesterase (BChE) and carboxylesterase (CbE) activities in Tupinambis merianae in order to obtain reference values for organophosphorus pesticide monitoring. Forty-two T. merianae individuals were grouped by sex and size to identify potential differences in their enzyme levels to allow for proper representation of normal values for females, males, juveniles, and hatchlings. Mean CbE was determined using two model substrates: alpha-naphtylacetate (α-NA) and p-nitrophenyl valerate (4-NPV). BChE and CbE sensitivity to malaoxon (Mx) was also evaluated as well as the possibility of BChE reactivation with pyridine-2-aldoxime methochloride (2-PAM). Mean adult females' BChE was significantly higher than adult males, juveniles, and hatchlings. No significant differences were found between groups regarding CbE. CbE (4-NPV) activity showed slightly negative correlation with lizard snout-vent length, while BChE and CbE (α-NA) showed no correlation with body size. Apparent IC(50) values for BChE and CbE (α-NA) suggested different sensitivities among groups. CbE (4-NPV) could not be inhibited. All Mx-inhibited groups treated with 2-PAM in a final concentration of 2.8 mM showed clear signs of reactivation. In conclusion, the results demonstrate that (1) plasma esterase activity did not vary with age and sex, except for BChE activity, and (2) because biological and environmental variables could be confounding factors in the response of plasma cholinesterases, complementary biomarkers like CbE inhibition and oxime-induced reactivation of esterases are strongly recommended.

  4. Systemic effects of chronically administered methyl prednisolonate and methyl 17-deoxyprednisolonate.

    Science.gov (United States)

    Olejniczak, E; Lee, H J

    1984-06-01

    The systemic activities of methyl prednisolonate and methyl 17-deoxyprednisolonate (1) were studied in rats. Methyl 17-deoxyprednisolonate produced significant changes in the amount of sodium ion (decreased) and potassium ion (increased) in urine; however, methyl prednisolonate had no effect on electrolyte balance. Both methyl prednisolonate and methyl 17-deoxyprednisolonate had no effect on liver glycogen content, plasma corticosterone level and relative adrenal weight. In contrast, the parent compound prednisolone caused a significant decrease in liver glycogen content, plasma corticosterone level and relative adrenal weight.

  5. Human Cell Line Activation Test of the Novel Energetics Methyl Trinitropryrazol (MTNP) and 1,3-Dimethylhexahydropyrimidine (DHP)

    Science.gov (United States)

    2017-11-01

    costs, conserve physical resources, and sustain the health of those potentially exposed. The U.S. Army RDECOM, ETAP has been dedicated to finding...trinitropryrazol (MTNP) and 1,3-dimethylhexahydropyrimidine (DHP) Prepared by: Emily Reinke, Ph.D. Health Effects Division Toxicology...the Novel Energetics methyl trinitropyrazol (MTNP) and 1,3-dimethylhexahydropyrimidine (DHP) Emily N. Reinke, Ph.D. Army Public Health Center

  6. Enzymatic degradation of lignin‐carbohydrate complexes (LCCs): Model studies using a fungal glucuronoyl esterase from Cerrena unicolor

    DEFF Research Database (Denmark)

    d'Errico, Clotilde; Jørgensen, Jonas O.; Krogh, Kristian B. R. M.

    2015-01-01

    Lignin‐carbohydrate complexes (LCCs) are believed to influence the recalcitrance of lignocellulosic plant material preventing optimal utilization of biomass in e.g. forestry, feed and biofuel applications. The recently emerged carbohydrate esterase (CE) 15 family of glucuronoyl esterases (GEs) has...

  7. Bacillus sp. JR3 esterase LipJ: A new mesophilic enzyme showing traces of a thermophilic past.

    Directory of Open Access Journals (Sweden)

    Judit Ribera

    Full Text Available A search for extremophile enzymes from ancient volcanic soils in El Hierro Island (Canary Islands, Spain allowed isolation of a microbial sporulated strain collection from which several enzymatic activities were tested. Isolates were obtained after sample cultivation under several conditions of nutrient contents and temperature. Among the bacterial isolates, supernatants from the strain designated JR3 displayed high esterase activity at temperatures ranging from 30 to 100°C, suggesting the presence of at least a hyper-thermophilic extracellular lipase. Sequence alignment of known thermophilic lipases allowed design of degenerated consensus primers for amplification and cloning of the corresponding lipase, named LipJ. However, the cloned enzyme displayed maximum activity at 30°C and pH 7, showing a different profile from that observed in supernatants of the parental strain. Sequence analysis of the cloned protein showed a pentapeptide motif -GHSMG- distinct from that of thermophilic lipases, and much closer to that of esterases. Nevertheless, the 3D structural model of LipJ displayed the same folding as that of thermophilic lipases, suggesting a common evolutionary origin. A phylogenetic study confirmed this possibility, positioning LipJ as a new member of the thermophilic family of bacterial lipases I.5. However, LipJ clusters in a clade close but separated from that of Geobacillus sp. thermophilic lipases. Comprehensive analysis of the cloned enzyme suggests a common origin of LipJ and other bacterial thermophilic lipases, and highlights the most probable divergent evolutionary pathway followed by LipJ, which during the harsh past times would have probably been a thermophilic enzyme, having lost these properties when the environment changed to more benign conditions.

  8. Bacillus sp. JR3 esterase LipJ: A new mesophilic enzyme showing traces of a thermophilic past.

    Science.gov (United States)

    Ribera, Judit; Estupiñán, Mónica; Fuentes, Alba; Fillat, Amanda; Martínez, Josefina; Diaz, Pilar

    2017-01-01

    A search for extremophile enzymes from ancient volcanic soils in El Hierro Island (Canary Islands, Spain) allowed isolation of a microbial sporulated strain collection from which several enzymatic activities were tested. Isolates were obtained after sample cultivation under several conditions of nutrient contents and temperature. Among the bacterial isolates, supernatants from the strain designated JR3 displayed high esterase activity at temperatures ranging from 30 to 100°C, suggesting the presence of at least a hyper-thermophilic extracellular lipase. Sequence alignment of known thermophilic lipases allowed design of degenerated consensus primers for amplification and cloning of the corresponding lipase, named LipJ. However, the cloned enzyme displayed maximum activity at 30°C and pH 7, showing a different profile from that observed in supernatants of the parental strain. Sequence analysis of the cloned protein showed a pentapeptide motif -GHSMG- distinct from that of thermophilic lipases, and much closer to that of esterases. Nevertheless, the 3D structural model of LipJ displayed the same folding as that of thermophilic lipases, suggesting a common evolutionary origin. A phylogenetic study confirmed this possibility, positioning LipJ as a new member of the thermophilic family of bacterial lipases I.5. However, LipJ clusters in a clade close but separated from that of Geobacillus sp. thermophilic lipases. Comprehensive analysis of the cloned enzyme suggests a common origin of LipJ and other bacterial thermophilic lipases, and highlights the most probable divergent evolutionary pathway followed by LipJ, which during the harsh past times would have probably been a thermophilic enzyme, having lost these properties when the environment changed to more benign conditions.

  9. Contributions of a unique β-clamp to substrate recognition illuminates the molecular basis of exolysis in ferulic acid esterases.

    Science.gov (United States)

    Gruninger, Robert J; Cote, Chris; McAllister, Tim A; Abbott, D Wade

    2016-04-01

    Lignocellulosic biomass is a promising renewable resource; however, deconstruction of this material is still the rate-limiting step. Major obstacles in the biocatalytic turnover of lignocellulose are ester-linked decorations that prevent access to primary structural polysaccharides. Enzymes targeting these esters represent promising biotools for increasing bioconversion efficiency. Ruminant livestock are unique in their ability to degrade lignocellulose through the action of their gut microbiome. The anaerobic fungi (phylum Neocallimastigomycota) are key members of this ecosystem that express a large repertoire of carbohydrate-active enzymes (CAZymes) with little sequence identity with characterized CAZymes [Lombard, Golaconda, Drula, Coutinho and Henrissat (2014) Nucleic Acids Res. 42: , D490-D495]. We have identified a carbohydrate esterase family 1 (CE1) ferulic acid esterase (FAE) belonging to Anaeromyces mucronatus(AmCE1/Fae1a), and determined its X-ray structure in both the presence [1.55 Å (1 Å=0.1 nm)] and absence (1.60 Å) of ferulic acid. AmCE1 adopts an α/β-hydrolase fold that is structurally conserved with bacterial FAEs, and possesses a unique loop, termed the β-clamp, that encloses the ligand. Isothermal titration calorimetry reveals that substrate binding is driven by enthalpic contributions, which overcomes a large entropic penalty. A comparative analysis of AmCE1 with related enzymes has uncovered the apparent structural basis for differential FAE activities targeting cross-linking ferulic acid conjugates compared with terminal decorations. Based on comparisons to structurally characterized FAEs, we propose that the β-clamp may define the structural basis of exolytic activities in FAEs. This provides a structure-based tool for predicting exolysis and endolysis in CE1. These insights hold promise for rationally identifying enzymes tailored for bioconversion of biomass with variations in cell wall composition. © 2016 Authors; published by

  10. Biomonitoring of ecosystem degradation caused by CPO waste of Mentaya River in Central Kalimantan use of esterase isozyme electromorph method

    Directory of Open Access Journals (Sweden)

    PRABANG SETYONO

    2008-07-01

    Full Text Available The impact of CPO (Crude Palm Oil dock activity in Mentaya River of Central Borneo caused degradation of ecosystem, particularly on both mangrove and macrozoobenthos community. One of methods used for monitoring of ecosystem degradation was to determine species that were still survive under the polluted conditions. These survival species were assumed to synthesize alloenzyme that can be used as indicator. Alloenzyme was synthesized as an effort of adaptation processes toward environmental pressures caused by CPO spill on Mentaya River. Alloenzyme would be expressed as phenotypic and genotypic adaptation processes or phenotypic plasticity. Research was carried out, consisted of field research included collecting sample and environmental data (oil content, temperature, pH, electric conductivity and redox potential, and laboratory research included series analysis of water quality (DO, BOD, COD, pH, TSS, TDS and also alloenzyme content of Soneratia caseolaris L. and Macrobrachium rosenbergii de Man. The alloenzyme of root and leaves mangrove and prawn’s hepatopancreas was analyzed using Spencer starch gel electrophoresis modified method of exposed on sucrose solution. Separated components of alloenzyme were detected by special staining for Esterase isozyme. The results revealed that Soneratia caseolaris L. and Macrobrachium rosenbergii de Man were bioindicator organisms for the polluted site by oil spills from CPO loading activities. The polluted river water by oil spill from CPO activities decreased redox potential, DO, increased oil content, DHL, water temperature, pH sediment, pH water, TDS, BOD, COD, TSS. Gel electrophoretical analysis demonstrated that Mangrove Soneratia caseolaris synthesized alloenzyme consisted of complex enzymes such as EST in its root and leave cells. Those enzymes were nearly similar to those of Macrobrachium rosenbergii. The oil spill from CPO have ester bonding so its adaptation mechanism with release Esterase

  11. Epigallocatechin gallate protects dopaminergic neurons against 1-methyl-4- phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity by inhibiting microglial cell activation.

    Science.gov (United States)

    Li, Rui; Peng, Ning; Du, Fang; Li, Xu-ping; Le, Wei-dong

    2006-04-01

    To observe whether the dopaminergic neuroprotective effect of (-)-epigallocatechin gallate (EGCG) is associated with its inhibition of microglial cell activation in vivo. The effects of EGCG at different doses on dopaminergic neuronal survival were tested in a methyl-4-phenyl-pyridinium (MPP+)-induced dopaminergic neuronal injury model in the primary mesencephalic cell cultures. With unbiased stereological method, tyrosine hydroxylase-immunoreactive (TH-ir) cells were counted in the A8, A9 and A10 regions of the substantia nigra (SN) in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated C57BL/6 mice. The effect of EGCG on microglial activation in the SN was also investigated. Pretreatment with EGCG (1 to 100 micromol/L) significantly attenuated MPP+-induced TH-ir cell loss by 22.2% to 80.5% in the mesencephalic cell cultures. In MPTP-treated C57BL/6 mice, EGCG at a low concentration (1 mg/kg) provided significant protection against MPTP-induced TH-ir cell loss by 50.9% in the whole nigral area and by 71.7% in the A9 region. EGCG at 5 mg/kg showed more prominent protective effect than at 1 or 10 mg/kg. EGCG pretreatment significantly inhibited microglial activation and CD11b expression induced by MPTP. EGCG exerts potent dopaminergic neuroprotective activity by means of microglial inhibition, which shed light on the potential use of EGCG in treatment of Parkinson's disease.

  12. Magnetic Fe{sub 2}MO{sub 4} (M:Fe, Mn) activated carbons: Fabrication, characterization and heterogeneous Fenton oxidation of methyl orange

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi Dung [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Phan, Ngoc Hoa [Department of Chemical Technology, Hochiminh University of Technology, 268 Ly Thuong Kiet, District 10, Ho Chi Minh (Viet Nam); Do, Manh Huy, E-mail: huydoma@vast-hcm.ac.vn [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); Ngo, Kim Tham [Institute of Chemical Technology, Vietnamese Academy of Science and Technology, 01 Mac Dinh Chi, District 1, Ho Chi Minh (Viet Nam); College of science, Can Tho University, 3/2, Can Tho (Viet Nam)

    2011-01-30

    We present a simple and efficient method for the fabrication of magnetic Fe{sub 2}MO{sub 4} (M:Fe and Mn) activated carbons (Fe{sub 2}MO{sub 4}/AC-H, M:Fe and Mn) by impregnating the activated carbon with simultaneous magnetic precursor and carbon modifying agent followed by calcination. The obtained samples were characterized by nitrogen adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), and the catalytic activity in heterogeneous Fenton oxidation of methyl orange (MO) was evaluated. The resulting Fe{sub 2}MnO{sub 4}/AC-H showed higher catalytic activity in the methyl orange oxidation than Fe{sub 3}O{sub 4}/AC-H. The effect of operational parameters (pH, catalyst loading H{sub 2}O{sub 2} dosage and initial MO concentration) on degradation performance of the oxidation process was investigated. Stability and reusability of selected catalyst were also tested.

  13. Geranyl acetate esterase controls and regulates the level of geraniol in lemongrass (Cymbopogon flexuosus Nees ex Steud.) mutant cv. GRL-1 leaves.

    Science.gov (United States)

    Ganjewala, Deepak; Luthra, Rajesh

    2009-01-01

    Essential oil isolated from lemongrass (Cymbopogon flexuosus) mutant cv. GRL-1 leaves is mainly composed of geraniol (G) and geranyl acetate (GA). The proportion of G and GA markedly fluctuates during leaf development. The proportions of GA and G in the essential oil recorded at day 10 after leaf emergence were approximately 59% and approximately 33% respectively. However, the level of GA went down from approximately 59 to approximately 3% whereas the level of G rose from approximately 33 to approximately 91% during the leaf growth period from day 10 to day 50. However, the decline in the level of GA was most pronounced in the early (day 10 to day 30) stage of leaf growth. The trend of changes in the proportion of GA and G has clearly indicated the role of an esterase that must be involved in the conversion of GA to G during leaf development. We isolated an esterase from leaves of different ages that converts GA into G and has been given the name geranyl acetate esterase (GAE). The GAE activity markedly varied during the leaf development cycle; it was closely correlated with the monoterpene (GA and G) composition throughout leaf development. GAE appeared as several isoenzymes but only three (GAE-I, GAE-II, and GAE-III) of them had significant GA cleaving activity. The GAE isoenzymes pattern was greatly influenced by the leaf developmental stages and so their GA cleaving activities. Like the GAE activity, GAE isoenzyme patterns were also found to be consistent with the monoterpene (GA and G) composition. GAE had an optimum pH at 8.5 and temperature at 30 degrees C. Besides GAE, a compound with phosphatase activity capable of hydrolyzing geranyl diphosphate (GPP) to produce geraniol has also been isolated.

  14. Synthesis of Fischer carbene complexes of iridium by C-H bond activation of methyl and cyclic ethers: Evidence for reversible {alpha}-hydrogen migration

    Energy Technology Data Exchange (ETDEWEB)

    Luecke, H.F.; Arndtsen, B.A.; Burger, P.; Bergman, R.G. [Lawrence Berkeley Lab., CA (United States)]|[Univ. of California, Berkeley, CA (United States)

    1996-03-13

    We report here a mild and versatile route to Fischer carbene complexes of iridium via the activation of C-H bonds of methyl and cyclic ethers, along with our preliminary studies of this rare family of carbene complexes. Theoretical studies suggest that {alpha}-hydrogen migrations can be kinetically favorable if a coordinatively unsaturated species can be accessed. Thus, the lability of the triflate ligand presumably facilitates this process. Further evidence for the rapidity, as well as reversibility, of this rearrangement was obtained by NMR analysis. 20 refs.

  15. In vitro antifungal activity of fatty acid methyl esters of the seeds of Annona cornifolia A.St.-Hil. (Annonaceae) against pathogenic fungus Paracoccidioides brasiliensis.

    Science.gov (United States)

    Lima, Luciana Alves Rodrigues dos Santos; Johann, Susana; Cisalpino, Patrícia Silva; Pimenta, Lúcia Pinheiro Santos; Boaventura, Maria Amélia Diamantino

    2011-01-01

    Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.

  16. Relationship between structure, conformational flexibility, and biological activity of agonists and antagonists at the N-methyl-D-aspartic acid subtype of excitatory amino acid receptors

    DEFF Research Database (Denmark)

    Madsen, U; Brehm, L; Schaumburg, Kjeld

    1990-01-01

    The relationship between conformational flexibility and agonist or antagonist actions at the N-Methyl-D-aspartic acid (NMDA) subtype of central L-glutamic acid (GLU) receptors of a series of racemic piperidinedicarboxylic acids (PDAs) was studied. The conformational analyses were based on 1H NMR...... receptors. Each of the three cyclic acidic amino acids showing NMDA agonist activities was found to exist as an equilibrium mixture of two conformers in aqueous solution. In contrast, the NMDA antagonists cis-2,3-PDA and cis-2,4-PDA as well as the inactive compounds trans-2,5-PDA and cis-2,6-PDA were shown...

  17. Rational design of a carboxylic esterase RhEst1 based on computational analysis of substrate binding.

    Science.gov (United States)

    Chen, Qi; Luan, Zheng-Jiao; Yu, Hui-Lei; Cheng, Xiaolin; Xu, Jian-He

    2015-11-01

    A new carboxylic esterase RhEst1 which catalyzes the hydrolysis of (S)-(+)-2,2-dimethylcyclopropanecarboxylate (S-DmCpCe), the key chiral building block of cilastatin, was identified and subsequently crystallized in our previous work. Mutant RhEst1A147I/V148F/G254A was found to show a 5-fold increase in the catalytic activity. In this work, molecular dynamic simulations were performed to elucidate the molecular determinant of the enzyme activity. Our simulations show that the substrate binds much more strongly in the A147I/V148F/G254A mutant than in wild type, with more hydrogen bonds formed between the substrate and the catalytic triad and the oxyanion hole. The OH group of the catalytic residue Ser101 in the mutant is better positioned to initiate the nucleophilic attack on S-DmCpCe. Interestingly, the "170-179" loop which is involved in shaping the catalytic sites and facilitating the product release shows remarkable dynamic differences in the two systems. Based on the simulation results, six residues were identified as potential "hot-spots" for further experimental testing. Consequently, the G126S and R133L mutants show higher catalytic efficiency as compared with the wild type. This work provides molecular-level insights into the substrate binding mechanism of carboxylic esterase RhEst1, facilitating future experimental efforts toward developing more efficient RhEst1 variants for industrial applications. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Selective Cytotoxic Activity of Se-Methyl-Seleno-L-Cysteine- and Se-Polysaccharide-Containing Extracts from Shiitake Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

    Science.gov (United States)

    Klimaszewska, Marzenna; Górska, Sandra; Dawidowski, Maciej; Podsadni, Piotr; Szczepanska, Agnieszka; Orzechowska, Emilia; Kurpios-Piec, Dagmara; Grosicka-Maciag, Emilia; Rahden-Staroń, Iwonna; Turło, Jadwiga

    2017-01-01

    Numerous formulations derived from the shiitake medicinal mushroom, Lentinus edodes, demonstrate anticancer activities. We hypothesized that isolates from selenium (Se)-enriched mycelia of L. edodes would possess stronger cancer-preventive properties than current preparations. The aim of this study was to investigate whether the presence of Se-methyl-seleno-L-cysteine in mycelial extracts of L. edodes affects their cytotoxic activity (makes them stronger) or whether they are as effective as Se-containing polysaccharides. Extracts were prepared from Se-containing mycelia under various conditions and assayed for cytotoxic activity in cancer (PC3 and HeLa) and normal (HMEC-1) cell lines. The chemical composition of the extracts was examined; specifically, the amounts of potentially cytotoxic Se compounds (methylselenocysteine, selenomethionine, and Se-containing polysaccharides) were measured. The relationship between extract composition and biological activity was characterized. Mycelial cultures were cultivated in a 10-L bioreactor in medium enriched with sodium selenite. Mycelial extracts were prepared either at 100°C or at 4°C in acidic solution. Total Se content was determined using the atomic absorption spectrometry method, and methylselenocysteine and selenomethionine contents were measured using reverse-phase high-performance liquid chromatography. Protein, carbohydrate, and polyphenolic contents were determined with spectrophotometric methods, and Se-containing polysaccharides were measured with the use of precipitation. Anticancer activity of mycelial extracts was examined using the MTT cell viability assay. Extracts containing Se-methyl-seleno-L-cysteine or Se-polysaccharides prepared at 4°C and 100°C, respectively, display moderate, time-dependent, specific cytotoxic activity in HeLa and PC3 cell lines. The effect in HeLa cells is more pronounced in the extract prepared at 4°C than at 100°C. The effect is almost equal for the PC3 cell line. However

  19. Synthesis and characterization of n-alkylamino derivatives of vitamin K3: Molecular structure of 2-propylamino-3-methyl-1,4-naphthoquinone and antibacterial activities

    Science.gov (United States)

    Chadar, Dattatray; Camilles, Maria; Patil, Rishikesh; Khan, Ayesha; Weyhermüller, Thomas; Salunke-Gawali, Sunita

    2015-04-01

    We would like to introduce eight analogues of n-alkylamino derivatives of vitamin K3 (2-methyl-1,4-naphthoquinone) viz, 2-(n-alkylamino)-3-methyl-1,4-naphthoquinone (where n-alkyl is methyl; LM-1, ethyl; LM-2, propyl; LM-3, butyl; LM-4, pentyl; LM-5, hexyl; LM-6, heptyl; LM-7, octyl; LM-8). All the above analogues have been successfully synthesized from vitamin K3 and characterized using different analytical techniques. Furthermore, in order to understand the mechanistic aspects of formation of LM-1 to LM-8 compounds, we could propose the mechanism. The FT-IR analysis of LM-1 to LM-8 indicate the presence of characteristic band of Nsbnd H group ∼3287-3364 cm-1, the variation was attributed to extensive intramolecular hydrogen bonding interaction. The molecular structure of LM-3 compound has been confirmed by single crystal X-ray diffraction analysis. LM-3 compound crystallises in triclinic space group P1. There were four independent molecules in asymmetric unit cell and their molecular interactions observed via Nsbnd H⋯O, Csbnd H⋯O and π-π stacking of quinonoid rings. Pharmacological potential of all compounds has been evaluated in terms of their antibacterial activities against Pseudomonas aeruginosa and Staphylococcus aureus. All the compounds were active against both the strains while LM-2 was found to be more effective with a minimum inhibition concentration of 0.3125 μg/mL and 0.156 μg/mL respectively.

  20. E3 protein of bovine coronavirus is a receptor-destroying enzyme with acetylesterase activity

    International Nuclear Information System (INIS)

    Vlasak, R.; Luytjes, W.; Leider, J.; Spaan, W.; Palese, P.

    1988-01-01

    In addition to members of the Orthomyxoviridae and Paramyxoviridae, several coronaviruses have been shown to possess receptor-destroying activities. Purified bovine coronavirus (BCV) preparations have an esterase activity which inactivates O-acetylsialic acid-containing receptors on erythrocytes. Diisopropyl fluorophosphate (DFP) completely inhibits this receptor-destroying activity of BCV, suggesting that the viral enzyme is a serine esterase. Treatment of purified BCV with [ 3 H]DFP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the proteins revealed that the esterase/receptor-destroying activity of BCV is associated with the E3 protein was specifically phosphorylated. This finding suggests that the esterase/receptor-destroying activity of BCV is associated with the E3 protein. Furthermore, treatment of BCV with DFP dramatically reduced its infectivity in a plaque assay. It is assumed that the esterase activity of BCV is required in an early step of virus replication, possible during virus entry or uncoating

  1. E3 protein of bovine coronavirus is a receptor-destroying enzyme with acetylesterase activity

    Energy Technology Data Exchange (ETDEWEB)

    Vlasak, R.; Luytjes, W.; Leider, J.; Spaan, W.; Palese, P.

    1988-12-01

    In addition to members of the Orthomyxoviridae and Paramyxoviridae, several coronaviruses have been shown to possess receptor-destroying activities. Purified bovine coronavirus (BCV) preparations have an esterase activity which inactivates O-acetylsialic acid-containing receptors on erythrocytes. Diisopropyl fluorophosphate (DFP) completely inhibits this receptor-destroying activity of BCV, suggesting that the viral enzyme is a serine esterase. Treatment of purified BCV with (/sup 3/H)DFP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the proteins revealed that the esterase/receptor-destroying activity of BCV is associated with the E3 protein was specifically phosphorylated. This finding suggests that the esterase/receptor-destroying activity of BCV is associated with the E3 protein. Furthermore, treatment of BCV with DFP dramatically reduced its infectivity in a plaque assay. It is assumed that the esterase activity of BCV is required in an early step of virus replication, possible during virus entry or uncoating.

  2. Activity coefficients at infinite dilution and enthalpies of solution of methanol, 1-butanol, and 1-hexanol in 1-hexyl-3-methyl-imidazolium bis(trifluoromethyl-sulfonyl) imide

    International Nuclear Information System (INIS)

    Heintz, Andreas; Verevkin, Sergey P.; Lehmann, Jochen K.; Vasiltsova, Tatiana V.; Ondo, Daniel

    2007-01-01

    Activity coefficients at infinite dilution γ i ∼ of methanol, 1-butanol, and 1-hexanol in the ionic liquid 1-hexyl-3-methyl-imidazolium bis(trifluoromethyl-sulfonyl) imide ([HMIM][NTf 2 ]) have been determined by gas chromatography using the ionic liquids as stationary phase. The measurements were carried out at different temperatures between 298K and 396K. From the temperature dependence of the limiting activity coefficients partial molar excess enthalpies at infinite dilution H i E,∼ of the alcohol in the ionic liquid have been derived. Additionally, enthalpies of solution of the same alcohols in the [HMIM][NTf 2 ] have been measured at T=298.15K in the range of low concentrations using titration calorimetry. Results at infinite dilution, H i E,∼ , are compared with those indirectly obtained from activity coefficients in infinite dilution γ i ∼ . Within the experimental error of both methods thermodynamic consistency has been confirmed

  3. Depletion of juvenile hormone esterase extends larval growth in Bombyx mori.

    Science.gov (United States)

    Zhang, Zhongjie; Liu, Xiaojing; Shiotsuki, Takahiro; Wang, Zhisheng; Xu, Xia; Huang, Yongping; Li, Muwang; Li, Kai; Tan, Anjiang

    2017-02-01

    Two major hormones, juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulate insect growth and development according to their precisely coordinated titres, which are controlled by both biosynthesis and degradation pathways. Juvenile hormone esterase (JHE) is the primary JH-specific degradation enzyme that plays a key role in regulating JH titers, along with JH epoxide hydrolase (JHEH) and JH diol kinase (JHDK). In the current study, a loss-of-function analysis of JHE in the silkworm, Bombyx mori, was performed by targeted gene disruption using the transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/RNA-guided Cas9 nucleases) system. Depletion of B. mori JHE (BmJHE) resulted in the extension of larval stages, especially the penultimate and ultimate larval stages, without deleterious effects to silkworm physiology. The expression of JHEH and JHDK was upregulated in mutant animals, indicating the existence of complementary routes in the JH metabolism pathway in which inactivation of one enzyme will activate other enzymes. RNA-Seq analysis of mutant animals revealed that genes involved in protein processing in the endoplasmic reticulum and in amino acid metabolism were affected by BmJHE depletion. Depletion of JHE and subsequent delayed JH metabolism activated genes in the TOR pathway, which are ultimately responsible for extending larval growth. The transgenic Cas9 system used in the current study provides a promising approach for analysing the actions of JH, especially in nondrosophilid insects. Furthermore, prolonging larval stages produced larger larvae and cocoons, which is greatly beneficial to silk production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. C1-esterase inhibitor protects against early vein graft remodeling under arterial blood pressure.

    Science.gov (United States)

    Krijnen, Paul A J; Kupreishvili, Koba; de Vries, Margreet R; Schepers, Abbey; Stooker, Wim; Vonk, Alexander B A; Eijsman, Leon; Van Hinsbergh, Victor W M; Zeerleder, Sacha; Wouters, Diana; van Ham, Marieke; Quax, Paul H A; Niessen, Hans W M

    2012-01-01

    Arterial pressure induced vein graft injury can result in endothelial loss, accelerated atherosclerosis and vein graft failure. Inflammation, including complement activation, is assumed to play a pivotal role herein. Here, we analyzed the effects of C1-esterase inhibitor (C1inh) on early vein graft remodeling. Human saphenous vein graft segments (n=8) were perfused in vitro with autologous blood either supplemented or not with purified human C1inh at arterial pressure for 6h. The vein segments and perfusion blood were analyzed for cell damage and complement activation. In addition, the effect of purified C1inh on vein graft remodeling was analyzed in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. Application of C1inh in the in vitro perfusion model resulted in significantly higher blood levels and significantly more depositions of C1inh in the vein wall. This coincided with a significant reduction in endothelial loss and deposition of C3d and C4d in the vein wall, especially in the circular layer, compared to vein segments perfused without supplemented C1inh. Administration of purified C1inh significantly inhibited vein graft intimal thickening in vivo in atherosclerotic C57Bl6/ApoE3 Leiden mice, wherein donor caval veins were interpositioned in the common carotid artery. C1inh significantly protects against early vein graft remodeling, including loss of endothelium and intimal thickening. These data suggest that it may be worth considering its use in patients undergoing coronary artery bypass grafting. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  5. Histone Methylation and microRNA-dependent Regulation of Epigenetic Activities in Neural Progenitor Self-Renewal and Differentiation.

    Science.gov (United States)

    Cacci, Emanuele; Negri, Rodolfo; Biagioni, Stefano; Lupo, Giuseppe

    2017-01-01

    Neural stem/progenitor cell (NSPC) self-renewal and differentiation in the developing and the adult brain are controlled by extra-cellular signals and by the inherent competence of NSPCs to produce appropriate responses. Stage-dependent responsiveness of NSPCs to extrinsic cues is orchestrated at the epigenetic level. Epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNA-mediated regulation control crucial aspects of NSPC development and function, and are also implicated in pathological conditions. While their roles in the regulation of stem cell fate have been largely explored in pluripotent stem cell models, the epigenetic signature of NSPCs is also key to determine their multipotency as well as their progressive bias towards specific differentiation outcomes. Here we review recent developments in this field, focusing on the roles of histone methylation marks and the protein complexes controlling their deposition in NSPCs of the developing cerebral cortex and the adult subventricular zone. In this context, we describe how bivalent promoters, carrying antagonistic epigenetic modifications, feature during multiple steps of neural development, from neural lineage specification to neuronal differentiation. Furthermore, we discuss the emerging cross-talk between epigenetic regulators and microRNAs, and how the interplay between these different layers of regulation can finely tune the expression of genes controlling NSPC maintenance and differentiation. In particular, we highlight recent advances in the identification of astrocyte-enriched microRNAs and their function in cell fate choices of NSPCs differentiating towards glial lineages.

  6. Identify function methyl cellulose glue of rehabilitation and activation in preparation Tissues used in restoration paper works

    Directory of Open Access Journals (Sweden)

    kobra dadmohammadi

    2017-08-01

    Full Text Available This article aims to facilitate the use of methyl cellulose adhesive to repair paper works that its ink is sensitive to water. This research is conducted by analytical comparisons method and samples is collected by experiments related to research topics such as pH measurement, Calorimetric, infrared spectroscopy with total attenuated reflection (FTIR- ATR, the measurement of tensile strength as well measurement of The adhesive strength of the samples. The stages of this study is conducted so that the adhesive methyl cellulose at a concentration of 7% in methanol was prepared. The prepared specimens is treated under Temperature-humidity accelerated aging in accordance with standard ASTM D4714-96 no for 384 hours and under light in accordance with ASTM D6789-02 for 360 hours and Changes of color, pH, tensile strength and adhesion is investigated for them. Results showed that the samples pH is changed from 6.91 to 6.39 after light aging and to 6.06 after temperature-humidity aging. Also, Tensile strength of Samples is reduced from 0.31 to 0.23 kN per meter after light aging and to 0.24 kN per meter after the temperature-humidity aging. Also, the adhesive strength of the samples is decreased from 1.43 to 0.97 Newton after light aging and to 1.51 Newton after temperature-humidity aging.

  7. Assessment of thermal neutron and N-methyl-N-nitrosourea activities in groups of barley mutants with possible breeding use

    International Nuclear Information System (INIS)

    Uhlik, J.; Burianova, S.

    1982-01-01

    During the study of genetic variability induced after the application of thermal neutrons and N-methyl-N-nitrosourea in barley, marked differences were manifest when selected mutated progeny sets with possible breeding use were evaluated. It is recommended on the basis of the results to use separately a chemical mutagen and a physical mutagen for influencing the same material in which it is intended to obtain the largest possible amount of mutated progenies that could be used in breeding. In the set of selected progenies offering the possibility of breeding use, thermal neutrons induced larger proportions of high-tillering progenies, progenies with preference to the first tillers, with longer stalks, with a firm stalk, with one stalk, with an erect ear with deformed spikelets, with ears having deformed first sections, later ripening, with earlier heading time. N-methyl-N-nitrosourea induced larger proportions of progenies with reduced wax production, with broader or narrow blades, with necrosis on leaves, with shorter stalks, with denser ears, with multiple-row ears, with shorter awns, with golden-coloured awns, with medium-early ripening, and with delayed heading time. (author)

  8. Synthesis, Spatial Structure and Analgesic Activity of Sodium 3-Benzylaminocarbonyl-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazin-4-olate Solvates

    Directory of Open Access Journals (Sweden)

    Igor V. Ukrainets

    2016-10-01

    Full Text Available In order to obtain and then test pharmocologically any possible conformers of the new feasible analgesic N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamide, its 4-O-sodium salt was synthesized using two methods. X-ray diffraction study made possible to determine that, depending on the chosen synthesis conditions, the above-mentioned compound forms either monosolvate with methanol or monohydrate, where organic anion exists in the form of three different conformers. Pharmacological testing of the two known pseudo-enantiomeric forms of the original N-benzylamide and of the two solvates of its sodium salt was performed simultaneously under the same conditions and in equimolar doses. Comparison of the results obtained while studying the peculiarities of the synthesized compounds spatial structure and biological properties revealed an important structure-action relationship. In particular, it was shown that the intensity of analgesic effect of different conformational isomers of N-benzyl-4-hydroxy-1-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxamide may change considerably: while low active conformers are comparable with piroxicam, highly active conformers are more than twice as effective as meloxicam.

  9. Down-Regulation of Neuropathy Target Esterase in Preeclampsia Placenta Inhibits Human Trophoblast Cell Invasion via Modulating MMP-9 Levels

    Directory of Open Access Journals (Sweden)

    Ting Zhong

    2018-02-01

    Full Text Available Background/Aims: Neuropathy target esterase (NTE, also known as neurotoxic esterase is proven to deacylate phosphatidylcholine (PC to glycerophosphocholine as a phospholipase B. Recently; studies showed that artificial phosphatidylserine/PC microvesicles can induce preeclampsia (PE-like changes in pregnant mice. However, it is unclear whether NTE plays a key role in the pathology of PE, a pregnancy-related disease, which was characterized by deficient trophoblast invasion and reduced trophoblast-mediated remodeling of spiral arteries. The aim of this study was to investigate the expression pattern of NTE in the placenta from women with PE and normal pregnancy, and the molecular mechanism of NTE involved in the development of PE. Methods: NTE expression levels in placentas from 20 pregnant women with PE and 20 healthy pregnant women were detected using quantitative PCR and immunohistochemistry staining. The effect of NTE on trophoblast migration and invasion and the underlying mechanisms were examined in HTR-8/SVneo cell lines by transfection method. Results: NTE mRNA and protein expression levels were significantly decreased in preeclamptic placentas than normal control. Over-expression of NTE in HTR-8/SVneo cells significantly promoted trophoblast cells migration and invasion and was associated with increased MMP-9 levels. Conversely, shRNA-mediated down-regulation of NTE markedly inhibited the cell migration and invasion. In addition, silencing NTE reduced the MMP-9 activity and phosphorylated Erk1/2 and AKT levels. Conclusions: Our results suggest that the decreased NTE may contribute to the development of PE through impairing trophoblast invasion by down-regulating MMP-9 via the Erk1/2 and AKT signaling pathway.

  10. Naturally occurring methyl salicylate glycosides.

    Science.gov (United States)

    Mao, Ping; Liu, Zizhen; Xie, Meng; Jiang, Rui; Liu, Weirui; Wang, Xiaohong; Meng, Shen; She, Gaimei

    2014-01-01

    As an important part of non steroids anti-inflammation drug (NSAIDs), salicylate has developed from natural substance salicylic acid to natrium salicylicum, to aspirin. Now, methyl salicylate glycoside, a new derivative of salicylic acid, is modified with a -COOH group integrated one methyl radical into formic ether, and a -OH linked with a monosaccharide, a disaccharide or a trisaccharide unit by glycosidic linkage. It has the similar pharmacological activities, anti-inflammatory, analgesic, antipyretic and antithrombotic as the previous salicylates' without resulting in serious side effects, particularly the gastrointestinal toxicity. Owing to the superiority of those significant bioactivities, methyl salicylate glycosides have became a hot research area in NSAIDs for several years. This paper compiles all 9 naturally occurring methyl salicylate glycosides, their distribution of the resource and pharmacological mechanism, which could contribute to the new drug discovery.

  11. Enrichment of maize and triticale bran with recombinant Aspergillus tubingensis ferulic acid esterase

    CSIR Research Space (South Africa)

    Zwane, EN

    2017-03-01

    Full Text Available acid, in particular for the enrichment of food substrates. A recombinant Aspergillus tubingensis ferulic acid esterase Type A (FAEA) was expressed in Aspergillus niger D15#26 and purified with anion-exchange chromatography (3487 U/mg, Km = 0.43 mM, Kcat...

  12. Esterase isozymes patterns of grape vine (Vitis vinifera L. are altered in response to fungicide exposure

    Directory of Open Access Journals (Sweden)

    Gleice Ribeiro Orasmo

    2015-10-01

    Full Text Available Current analysis characterizes the effect of different fungicides often applied for pest control on a-and b-esterase patterns of four economically important table-wine grape cultivars (Italia, Rubi, Benitaka and Brasil of Vitis vinifera. The a- and b-esterase patterns in bud leaves of the cultivars were assessed by native PAGE analysis. Cabrio Top® compound inhibited Est-2, Est-5, Est-6, Est-7, Est-8, Est-9 and Est-10 carboxylesterases, whereas Est-4, Est-11, Est-12, Est-13, Est-14 acetylesterases and Est-16 carboxylesterase were detected as weakly stained bands. Carboxylesterases and acetylesterases were also detected as weakly stained bands when exposed to fungicides Orthocide 500®, Positron Duo® and Folicur PM®. No changes in a- and b-esterase patterns were reported when the vines were exposed to the fungicides Rovral SC®, Kumulus DF®, Curzate M®, Score® or Cuprogarb 500®. The evidence of functional changes in carboxylesterase and acetylesterase levels in current study is a warning to grape producers on the dangers inherent in the indiscriminate use of potent and modern fungicides extensively used in agriculture. The inhibition effect of fungicides on esterase isozyme molecules seems to be independent of the fungicide chemical.

  13. Dampak Hipoksia Sistemik terhadap Malondialdehida, Glial Fibrillary Acidic Protein dan Aktivitas Asetilkolin Esterase Otak Tikus

    OpenAIRE

    Andriani Andriani; Ani Retno Prijanti; Ninik Mudjihartini; Sri Widia A. Jusman

    2016-01-01

    Hipoksia sistemik menyebabkan berkurangnya oksigen dan energi di otak sehingga memicupenglepasan neurotransmiter asetilkolin, meningkatkan radikal bebas dan glial fibrillary acidic protein (GFAP)yang berfungsi menjaga kekuatan membran. Tujuan penelitian untuk melihat gambaran adaptasi otak padahipoksia sistemik terhadap fungsi asetilkolin esterase, kerusakan membran sel neuron dan astrosit. Penelitiandilakukan di Laboratorium Biokimia & Biologi Molekuler FK Universitas Indonesia, pada ta...

  14. Hydrolysis of Wheat Arabinoxylan by Two Acetyl Xylan Esterases from Chaetomium thermophilum

    DEFF Research Database (Denmark)

    Tong, Xiaoxue; Lange, Lene; Grell, Morten Nedergaard

    2015-01-01

    The thermophilic filamentous ascomycete Chaetomium thermophilum produces functionally diverse hemicellulases when grown on hemicellulose as carbon source. Acetyl xylan esterase (EC 3.1.1.72) is an important accessory enzyme in hemicellulose biodegradation. Although the genome of C. thermophilum has...

  15. Production and partial characterisation of feruloyl esterase by Sporotrichum thermophile in solid-state fermentation

    DEFF Research Database (Denmark)

    Topakas, E.; Kalogeris, E.; Kekos, D.

    2003-01-01

    A number of factors affecting production of feruloyl esterase an enzyme that hydrolyse ester linkages of ferulic acid (FA) in plant cell walls, by the thermophylic fungus Sporotrichum thermophile under solid state fermentation (SSF) were investigated. Initial moisture content and type of carbon...

  16. Usefulness of Leukocyte Esterase Test Versus Rapid Strep Test for Diagnosis of Acute Strep Pharyngitis

    Directory of Open Access Journals (Sweden)

    Kumara V. Nibhanipudi MD

    2015-08-01

    Full Text Available Objective: A study to compare the usage of throat swab testing for leukocyte esterase on a test strip(urine dip stick-multi stick to rapid strep test for rapid diagnosis of Group A Beta hemolytic streptococci in cases of acute pharyngitis in children. Hypothesis: The testing of throat swab for leukocyte esterase on test strip currently used for urine testing may be used to detect throat infection and might be as useful as rapid strep. Methods: All patients who come with a complaint of sore throat and fever were examined clinically for erythema of pharynx, tonsils and also for any exudates. Informed consent was obtained from the parents and assent from the subjects. 3 swabs were taken from pharyngo-tonsillar region, testing for culture, rapid strep & Leukocyte Esterase. Results: Total number is 100. Cultures 9(+; for rapid strep== 84(- and16 (+; For LE== 80(- and 20(+ Statistics: From data configuration Rapid Strep versus LE test don’t seem to be a random (independent assignment but extremely aligned. The Statistical results show rapid and LE show very agreeable results. Calculated Value of Chi Squared Exceeds Tabulated under 1 Degree Of Freedom (P<.0.0001 reject Null Hypothesis and Conclude Alternative Conclusions: Leukocyte esterase on throat swab is as useful as rapid strep test for rapid diagnosis of strep pharyngitis on test strip currently used for urine dip stick causing acute pharyngitis in children.

  17. Trichoderma reesei CE16 acetyl esterase and its role in enzymatic degradation of acetylated hemicellulose

    DEFF Research Database (Denmark)

    Biely, Peter; Cziszarava, Maria; Agger, Jane W.

    2014-01-01

    Results The combined action of GH10 xylanase and acetylxylan esterases (AcXEs) leads to formation of neutral and acidic xylooligosaccharides with a few resistant acetyl groups mainly at their non-reducing ends. We show here that these acetyl groups serve as targets for TrCE16 AcE. The most promin...

  18. Crystallization and preliminary X-ray diffraction studies of the pneumococcal teichoic acid phosphorylcholine esterase Pce

    Energy Technology Data Exchange (ETDEWEB)

    Lagartera, Laura; González, Ana; Stelter, Meike; García, Pedro; Kahn, Richard; Menéndez, Margarita; Hermoso, Juan A., E-mail: xjuan@iqfr.csic.es

    2005-02-01

    The modular choline-binding protein Pce, the phosphorylcholine esterase from S. pneumoniae, has been crystallized by the hanging-drop vapour-diffusion method. A SAD data set from a derivative with a gadolinium complex has been collected to 2.7 Å resolution.

  19. Cloning, Characterization, Controlled Overexpression, and Inactivation of the Major Tributyrin Esterase Gene of Lactococcus lactis

    NARCIS (Netherlands)

    Fernández, Leonides; Beerthuyzen, Marke M.; Brown, Julie; Siezen, Roland J.; Coolbear, Tim; Holland, Ross; Kuipers, Oscar P.

    2000-01-01

    The gene encoding the major intracellular tributyrin esterase of Lactococcus lactis was cloned using degenerate DNA probes based on 19 known N-terminal amino acid residues of the purified enzyme. The gene, named estA, was sequenced and found to encode a protein of 258 amino acid residues. The

  20. Preliminary X-ray Study of Naproxen Esterase from Bacillus subtilis

    NARCIS (Netherlands)

    van der Laan, Jan; Teplyakov, A.V.; Lammers, A.A.; Dijkstra, B.W.

    1993-01-01

    Single crystals of naproxen esterase from Bacillus subtilis have been obtained from PEG6000 solutions at pH 8.0 by liquid-liquid diffusion while applying a temperature gradient from 4°C to room temperature over a period of four weeks. The crystals belong to the trigonal space group P3121 or P3221

  1. Molecular population genetics of the β-esterase gene cluster of ...

    Indian Academy of Sciences (India)

    We suggest that the demographic history (bottleneck and admixture of genetically differentiated populations) is the major factor shaping the pattern of nucleotide polymorphism in the -esterase gene cluster. However there are some 'footprints' of directional and balancing selection shaping specific distribution of nucleotide ...

  2. Kinetics of the inhibitory interaction of organophosphorus neuropathy inducers and non-inducers in soluble esterases in the avian nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Mangas, Iris; Vilanova, Eugenio; Estevez, Jorge, E-mail: jorge.estevez@umh.es

    2011-11-15

    Some published studies suggest that low level exposure to organophosphorus esters (OPs) may cause neurological and neurobehavioral effects at long term exposure. These effects cannot be explained by action on known targets. In this work, the interactions (inhibition, spontaneous reactivation and 'ongoing inhibition') of two model OPs (paraoxon, non neuropathy-inducer, and mipafox, neuropathy-inducer) with the chicken brain soluble esterases were evaluated. The best-fitting kinetic model with both inhibitors was compatible with three enzymatic components. The amplitudes (proportions) of the components detected with mipafox were similar to those obtained with paraoxon. These observations confirm the consistency of the results and the model applied and may be considered an external validation. The most sensitive component (E{alpha}) for paraoxon (11-23% of activity, I{sub 50} (30 min) = 9-11 nM) is also the most sensitive for mipafox (I{sub 50} (30 min) = 4 nM). This component is spontaneously reactivated after inhibition with paraoxon. The second sensitive component to paraoxon (E{beta}, 71-84% of activity; I{sub 50} (30 min) = 1216 nM) is practically resistant to mipafox. The third component (E{gamma}, 5-8% of activity) is paraoxon resistant and has I{sub 50} (30 min) of 3.4 {mu}M with mipafox, similar to NTE (neuropathy target esterase). The role of these esterases remains unknown. Their high sensitivity suggests that they may either play a role in toxicity in low-level long-term exposure of organophosphate compounds or have a protective effect related with the spontaneous reactivation. They will have to be considered in further metabolic and toxicological studies. -- Research Highlights: Black-Right-Pointing-Pointer Paraoxon and mipafox interactions have been evaluated with chicken soluble brain esterases. Black-Right-Pointing-Pointer The paraoxon inhibition was analyzed considering the simultaneous spontaneous reactivation. Black

  3. Kinetics of the inhibitory interaction of organophosphorus neuropathy inducers and non-inducers in soluble esterases in the avian nervous system

    International Nuclear Information System (INIS)

    Mangas, Iris; Vilanova, Eugenio; Estévez, Jorge

    2011-01-01

    Some published studies suggest that low level exposure to organophosphorus esters (OPs) may cause neurological and neurobehavioral effects at long term exposure. These effects cannot be explained by action on known targets. In this work, the interactions (inhibition, spontaneous reactivation and “ongoing inhibition”) of two model OPs (paraoxon, non neuropathy-inducer, and mipafox, neuropathy-inducer) with the chicken brain soluble esterases were evaluated. The best-fitting kinetic model with both inhibitors was compatible with three enzymatic components. The amplitudes (proportions) of the components detected with mipafox were similar to those obtained with paraoxon. These observations confirm the consistency of the results and the model applied and may be considered an external validation. The most sensitive component (Eα) for paraoxon (11–23% of activity, I 50 (30 min) = 9–11 nM) is also the most sensitive for mipafox (I 50 (30 min) = 4 nM). This component is spontaneously reactivated after inhibition with paraoxon. The second sensitive component to paraoxon (Eβ, 71–84% of activity; I 50 (30 min) = 1216 nM) is practically resistant to mipafox. The third component (Eγ, 5–8% of activity) is paraoxon resistant and has I 50 (30 min) of 3.4 μM with mipafox, similar to NTE (neuropathy target esterase). The role of these esterases remains unknown. Their high sensitivity suggests that they may either play a role in toxicity in low-level long-term exposure of organophosphate compounds or have a protective effect related with the spontaneous reactivation. They will have to be considered in further metabolic and toxicological studies. -- Research Highlights: ► Paraoxon and mipafox interactions have been evaluated with chicken soluble brain esterases. ► The paraoxon inhibition was analyzed considering the simultaneous spontaneous reactivation. ► The best-fitting kinetic models were compatible with a three enzymatic components. ► The amplitudes of the

  4. Functional tuning of the catalytic residue pKa in a de novo designed esterase.

    Science.gov (United States)

    Hiebler, Katharina; Lengyel, Zsófia; Castañeda, Carlos A; Makhlynets, Olga V

    2017-09-01

    AlleyCatE is a de novo designed esterase that can be allosterically regulated by calcium ions. This artificial enzyme has been shown to hydrolyze p-nitrophenyl acetate (pNPA) and 4-nitrophenyl-(2-phenyl)-propanoate (pNPP) with high catalytic efficiency. AlleyCatE was created by introducing a single-histidine residue (His 144 ) into a hydrophobic pocket of calmodulin. In this work, we explore the determinants of catalytic properties of AlleyCatE. We obtained the pK a value of the catalytic histidine using experimental measurements by NMR and pH rate profile and compared these values to those predicted from electrostatics pK a calculations (from both empirical and continuum electrostatics calculations). Surprisingly, the pK a value of the catalytic histidine inside the hydrophobic pocket of calmodulin is elevated as compared to the model compound pK a value of this residue in water. We determined that a short-range favorable interaction with Glu 127 contributes to the elevated pK a of His 144 . We have rationally modulated local electrostatic potential in AlleyCatE to decrease the pK a of its active nucleophile, His 144 , by 0.7 units. As a direct result of the decrease in the His 144 pK a value, catalytic efficiency of the enzyme increased by 45% at pH 6. This work shows that a series of simple NMR experiments that can be performed using low field spectrometers, combined with straightforward computational analysis, provide rapid and accurate guidance to rationally improve catalytic efficiency of histidine-promoted catalysis. Proteins 2017; 85:1656-1665. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.