WorldWideScience

Sample records for arabinoxylan feruloyl transferase

  1. Feruloyl-CoA:monolignol transferase

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Curtis; Ralph, John; Withers, Saunia; Mansfield, Shawn D.

    2016-09-13

    The invention relates to nucleic acids encoding a feruloyl-CoA:monolignol transferase and the feruloyl-CoA:monolignol transferase enzyme that enables incorporation of monolignol ferulates, for example, including p-coumaryl ferulate, coniferyl ferulate, and sinapyl ferulate, into the lignin of plants.

  2. Quantitative Profiling of Feruloylated Arabinoxylan Side-Chains from Graminaceous Cell Walls

    Science.gov (United States)

    Schendel, Rachel R.; Meyer, Marleen R.; Bunzel, Mirko

    2016-01-01

    Graminaceous arabinoxylans are distinguished by decoration with feruloylated monosaccharidic and oligosaccharidic side-chains. Although it is hypothesized that structural complexity and abundance of these feruloylated arabinoxylan side-chains may contribute, among other factors, to resistance of plant cell walls to enzymatic degradation, quantitative profiling approaches for these structural units in plant cell wall materials have not been described yet. Here we report the development and application of a rapid and robust method enabling the quantitative comparison of feruloylated side-chain profiles in cell wall materials following mildly acidic hydrolysis, C18-solid phase extraction (SPE), reduction under aprotic conditions, and liquid chromatography with diode-array detection/mass spectrometry (LC-DAD/MS) separation and detection. The method was applied to the insoluble fiber/cell wall materials isolated from 12 whole grains: wild rice (Zizania aquatica L.), long-grain brown rice (Oryza sativa L.), rye (Secale cereale L.), kamut (Triticum turanicum Jakubz.), wheat (Triticum aestivum L.), spelt (Triticum spelta L.), intermediate wheatgrass (Thinopyrum intermedium), maize (Zea mays L.), popcorn (Zea mays L. var. everta), oat (Avena sativa L.) (dehulled), barley (Hordeum vulgare L.) (dehulled), and proso millet (Panicum miliaceum L.). Between 51 and 96% of the total esterified monomeric ferulates were represented in the quantified compounds captured in the feruloylated side-chain profiles, which confirms the significance of these structures to the global arabinoxylan structure in terms of quantity. The method provided new structural insights into cereal grain arabinoxylans, in particular, that the structural moiety α-l-galactopyranosyl-(1→2)-β-d-xylopyranosyl-(1→2)-5-O-trans-feruloyl-l-arabinofuranose (FAXG), which had previously only been described in maize, is ubiquitous to cereal grains. PMID:26834763

  3. Feruloylated Arabinoxylans Are Oxidatively Cross-Linked by Extracellular Maize Peroxidase but Not by Horseradish Peroxidase

    Institute of Scientific and Technical Information of China (English)

    Sally J. Burr; Stephen C. Fry

    2009-01-01

    Covalent cross-linking of soluble extraceUular arabinoxylans in living maize cultures, which models the cross-linking of wall-bound arabinoxylans, is due to oxidation of feruloyl esters to oligoferuloyl esters and ethers. The oxidizing system responsible could be H_2O_2/peroxidase, O_2/laccase, or reactive oxygen species acting non-enzymically. To distinguish these possibilities, we studied arabinoxylan cross-linking in vivo and in vitro. In living cultures, exogenous, soluble, extra-cellular, feruloylated [pentosyl-~3H]arabinoxylans underwent cross-linking, beginning abruptly 8 d after sub-culture. Cross-linking was suppressed by iodide, an H_2O_2 scavenger, indicating dependence on endogenous H2O2. However, exogenous H_2O_2 did not cause precocious cross-linking, despite the constant presence of endogenous peroxidases, suggesting that younger cultures contained natural cross-linking inhibitors. Dialysed culture-filtrates cross-linked [~3H]arabinoxylans in vitro only if H_20_2 was also added, indicating a peroxiclase requirement. This cross-linking was highly ionic-strength-dependent. The peroxidases responsible were heat-labile, although relatively heat-stable peroxidases (assayed on o-dianisidine) were also present, Surprisingly, added horseradish peroxidase, even after heat-denaturation, blocked the arabinoxylan-cross-linking action of maize peroxidases, suggesting that the horseradish protein was a competing substrate for [~3H]arabino-xylan coupling. In conclusion, we show for the first time that cross-linking of extracellular arabinoxylan in living maize cultures is an action of apoplastic peroxidases, some of whose unusual properties we report.

  4. Inhibition of Intestinal α-Glucosidase and Glucose Absorption by Feruloylated Arabinoxylan Mono- and Oligosaccharides from Corn Bran and Wheat Aleurone

    Directory of Open Access Journals (Sweden)

    Lovemore Nkhata Malunga

    2016-01-01

    Full Text Available The effect of feruloylated arabinoxylan mono- and oligosaccharides (FAXmo on mammalian α-glucosidase and glucose transporters was investigated using human Caco-2 cells, rat intestinal acetone powder, and Xenopus laevis oocytes. The isolated FAXmo from wheat aleurone and corn bran were identified to have degree of polymerization (DP of 4 and 1, respectively, by HPLC-MS. Both FAXmo extracts were effective inhibitors of sucrase and maltase functions of the α-glucosidase. The IC50 for FAXmo extracts on Caco-2 cells and rat intestinal α-glucosidase was 1.03–1.65 mg/mL and 2.6–6.5 mg/mL, respectively. Similarly, glucose uptake in Caco-2 cells was inhibited up to 40%. The inhibitory effect of FAXmo was dependent on their ferulic acid (FA content (R = 0.95. Sodium independent glucose transporter 2 (GLUT2 activity was completely inhibited by FAXmo in oocytes injected to express GLUT2. Our results suggest that ferulic acid and feruloylated arabinoxylan mono-/oligosaccharides have potential for use in diabetes management.

  5. Inhibition of Intestinal α-Glucosidase and Glucose Absorption by Feruloylated Arabinoxylan Mono- and Oligosaccharides from Corn Bran and Wheat Aleurone.

    Science.gov (United States)

    Malunga, Lovemore Nkhata; Eck, Peter; Beta, Trust

    2016-01-01

    The effect of feruloylated arabinoxylan mono- and oligosaccharides (FAXmo) on mammalian α-glucosidase and glucose transporters was investigated using human Caco-2 cells, rat intestinal acetone powder, and Xenopus laevis oocytes. The isolated FAXmo from wheat aleurone and corn bran were identified to have degree of polymerization (DP) of 4 and 1, respectively, by HPLC-MS. Both FAXmo extracts were effective inhibitors of sucrase and maltase functions of the α-glucosidase. The IC50 for FAXmo extracts on Caco-2 cells and rat intestinal α-glucosidase was 1.03-1.65 mg/mL and 2.6-6.5 mg/mL, respectively. Similarly, glucose uptake in Caco-2 cells was inhibited up to 40%. The inhibitory effect of FAXmo was dependent on their ferulic acid (FA) content (R = 0.95). Sodium independent glucose transporter 2 (GLUT2) activity was completely inhibited by FAXmo in oocytes injected to express GLUT2. Our results suggest that ferulic acid and feruloylated arabinoxylan mono-/oligosaccharides have potential for use in diabetes management.

  6. The potato suberin feruloyl transferase FHT which accumulates in the phellogen is induced by wounding and regulated by abscisic and salicylic acids.

    Science.gov (United States)

    Boher, Pau; Serra, Olga; Soler, Marçal; Molinas, Marisa; Figueras, Mercè

    2013-08-01

    The present study provides new insights on the role of the potato (Solanum tuberosum) suberin feruloyl transferase FHT in native and wound tissues, leading to conclusions about hitherto unknown properties of the phellogen. In agreement with the enzymatic role of FHT, it is shown that its transcriptional activation and protein accumulation are specific to tissues that undergo suberization such as the root boundary layers of the exodermis and the endodermis, along with the tuber periderm. Remarkably, FHT expression and protein accumulation within the periderm is restricted to the phellogen derivative cells with phellem identity. FHT levels in the periderm are at their peak near harvest during periderm maturation, with the phellogen becoming meristematically inactive and declining thereafter. However, periderm FHT levels remain high for several months after harvest, suggesting that the inactive phellogen retains the capacity to synthesize ferulate esters. Tissue wounding induces FHT expression and the protein accumulates from the first stages of the healing process onwards. FHT is up-regulated by abscisic acid and down-regulated by salicylic acid, emphasizing the complex regulation of suberin synthesis and wound healing. These findings open up new prospects important for the clarification of the suberization process and yield important information with regard to the skin quality of potatoes. PMID:23918964

  7. Enzymatic Xylose Release from Pretreated Corn Bran Arabinoxylan: Differential Effects of Deacetylation and Deferuloylation on Insoluble and Soluble Substrate Fractions

    DEFF Research Database (Denmark)

    Agger, Jane; Viksø-Nielsen, Ander; Meyer, Anne S.

    2010-01-01

    , and a β-xylosidase. The pretreatment divided the corn bran material 50:50 into soluble and insoluble fractions having A:X ratios of 0.66 and 0.40, respectively. Addition of acetyl xylan esterase to the monocomponent enzyme mixture almost doubled the xylose release from the insoluble substrate fraction...... and gave release of 1 mol of xylose/mol of acetic acid released, whereas addition of feruloyl esterase promoted release of only 0.4 mol of xylose/mol of ferulic acid released. For the soluble substrate fraction up to 36% of the xylose could be released by the enzymatic treatment. Acetyl xylan esterase...... the acetyl xylan esterase was more important for the enzymatic degradation than feruloyl esterase, whereas on soluble arabinoxylan the feruloyl esterase seemed to be more important for the release of xylose....

  8. Arabinoxylan-degrading enzyme system of the fungus Aspergillus awamori: purification and properties of an alpha-L-arabinofuranosidase.

    Science.gov (United States)

    Wood, T M; McCrae, S I

    1996-05-01

    An alpha-L-arabinofuranosidase produced by the fungus Aspergillus awamori had a molecular mass of approximately 64 kDa on sodium dodecyl sulphate/polyacrylamide gel electrophoresis (SDS-PAGE) and was optimally active at pH 4.6 and 50 degrees C. The enzyme, which chromatographed as a single component on SDS-PAGE, appeared to consist of two isoenzymes of pI 3.6 and 3.2. Acting in isolation, the alpha-L-arabinofuranosidase had only a very limited capacity to release L-arabinose (less than 11%) directly from arabinoxylans that had been extracted from a number of plant cell wall preparations using 18% alkali, but a much higher proportion of the L-arabinose (46%) was released from a wheat straw arabinoxylan that had been isolated by steam treatment. There was a marked synergistic effect between the alpha-L-arabinofuranosidase and an endo-(1 --> 4)-beta-D-xylanase produced by A. awamori in both the rate and extent of the release of L-arabinose from both oat straw and wheat straw arabinoxylans, suggesting that L-arabinose-substituted oligosaccharides generated by the endoxylanase action were better substrates for enzyme action. A novel property of the alpha-L-arabinofuranosidase was its capacity to release a substantial proportion (42%) of feruloyl L-arabinose from intact wheat straw arabinoxylan. The concerted action of the alpha-L-arabinofuranosidase and endoxylanase released 71% of the feruloyl L-arabinose and 69% of the p-coumaroyl L-arabinose substituents from wheat straw arabinoxylan.

  9. Dietary fibers - purification, structure and their health benefits with particular reference to feruloyl arabinoxylans

    DEFF Research Database (Denmark)

    Rao, Shyama Prasad; Muralikrishna, G

    2011-01-01

    The nature of carbohydrates present in the food is growing field of interest within the food industry due to the potential of some of them to help prevent diseases of lifestyle. Non-glycemic carbohydrates, i.e., those carbohydrates (or their components) that are not absorbed in the small intestin...

  10. Arabinoxylans, gut microbiota and immunity.

    Science.gov (United States)

    Mendis, Mihiri; Leclerc, Estelle; Simsek, Senay

    2016-03-30

    Arabinoxylan (AX) is a non-starch polysaccharide found in many cereal grains and is considered as a dietary fiber. Despite their general structure, there is structural heterogeneity among AX originating from different botanical sources. Furthermore, the extraction procedure and hydrolysis by xylolytic enzymes can further render differences to theses AX. The aim of this review was to address the effects of AX on the gut bacteria and their immunomodulatory properties. Given the complex structure of AX, we also aimed to discuss how the structural heterogeneity of AX affects its role in bacterial growth and immunomodulation. The existing literature indicates the role of fine structural details of AX on its potential as polysaccharides that can impact the gut associated microbial growth and immune system. PMID:26794959

  11. Structural Characterisation by ESI-MS of Feruloylated Arabino-oligosaccharides Synthesised by Chemoenzymatic Esterification

    Directory of Open Access Journals (Sweden)

    Paul Christakopoulos

    2007-07-01

    Full Text Available The chemoenzymatic synthesis of feruloylated arabino-oligosaccharides has been achieved, using a feruloyl esterase type C from Sporotrichum thermophile (StFaeC.The structure of the feruloylated products was confirmed by ESI-MSn.

  12. Maize Arabinoxylan Gels as Protein Delivery Matrices

    Directory of Open Access Journals (Sweden)

    Ana Luisa Martínez-López

    2009-04-01

    Full Text Available The laccase induced gelation of maize bran arabinoxylans at 2.5% (w/v in the presence of insulin or β-lactoglobulin at 0.1% (w/v was investigated. Insulin and β-lacto-globulin did not modify either the gel elasticity (9 Pa or the cross-links content (0.03 and 0.015 mg di- and triferulic acids/mg arabinoxylan, respectively. The protein release capability of the gel was also investigated. The rate of protein release from gels was dependent on the protein molecular weight. The apparent diffusion coefficient was 0.99 × 10-7 and 0.79 × 10-7 cm2/s for insulin (5 kDa and β-lactoglobulin (18 kDa, respectively. The results suggest that maize bran arabinoxylan gels can be potential candidates for the controlled release of proteins.

  13. Enzymatic hydrolysis of corn bran arabinoxylan

    DEFF Research Database (Denmark)

    Agger, Jane

    in a complex and ridig cell wall structure. This thesis contains a thorough examination of the monosaccharide and structural composition of corn bran, which is used to assess and apply the relevant mono component enzyme preparations. In this way, the aim is to obtain the most effective minimal enzymatic...... is mainly composed by heat, acid and alkali labile linkages in arabinoxylan. It therefore becomes a balancing task to find optimum conditions that compromise the advantages and disadvantages. Acidic pretreatments (pH 1.5-2) are found to be particularly effective in promoting the enzymatic hydrolysis......-linkings between arabinoxylans, which have been believed to be a major obstical for enzymatic hydrolysis. The chemical removal of these cross-links allows for the interpretation of hindering effects of cross-linking and it is concluded that they do not pose a significant barrier for enzymatic hydrolysis...

  14. Pilot-scale bioreactor production and long term stability of feruloyl soy glycerides

    Science.gov (United States)

    Soybean oil was transesterified with ethyl ferulate at 60 °C using the immobilized lipase Candida antartica lipase B (Novozym 435) to produce a mixture of feruloylated monoacylglycerols and feruloylated diacylglycerols homologues, collectively referred to as feruloylated soy glycerides (FSG). A 1-to...

  15. Concentration and shear rate dependence of solution viscosity for arabinoxylans from different sources

    Science.gov (United States)

    Arabinoxylans are cell wall polysaccharides abundant in plants. Alkaline extraction is commonly used to isolate arabinoxylans from cell wall rich materials, such as cereal brans, crop residues etc. While arabinoxylans from certain sources such as wheat endosperm, corn bran and rye bran have been wid...

  16. Arabinoxylan content and characterisation throughout the bread-baking process

    Science.gov (United States)

    End-use quality of wheat (Triticum aestivum L.) is influenced in a variety of ways by non-starch polysaccharides, especially arabinoxylans (AX). The assessment of AX content and structural properties is often performed on flour and extrapolated to predict the role that AX may play in baked products....

  17. POD promoted oxidative gelation of water-extractable arabinoxylan through ferulic acid dimers. Evidence for its negative effect on malt filterability.

    Science.gov (United States)

    Wu, Dianhui; Zhou, Ting; Li, Xiaomin; Cai, Guolin; Lu, Jian

    2016-04-15

    As a major component of non-starch polysaccharide in barley, arabinoxylan (AX) plays an important role in quality traits of malt and the final beer product. The Chinese barley malt has encountered filterability problems for a long time. The main reason caused by barley cultivar has been accepted in the malting and brewing industries. In our previous proteomic study, the peroxidase (POD) BP1 was found to be in quite high abundant in the filterability defect Chinese barley malt. Therefore, the present study tried to verify its negative effect on filterability, by surveying its activity in different malt samples and detecting effects of POD on AX gelation and filterability. The results showed that the activity of POD, as well as the content of AX bounded ferulic acid, were both negatively correlated with filterability, while the feruloyl esterase activity was positively correlated with it. In addition, AX gelation catalyzed by POD caused worse filterability, and the natural inhibitor of POD, vitamin C, could blocked the cross linking catalyzed by POD and thus improve the filterability. These results all suggested the great negative effect of POD on malt filterability. PMID:26616970

  18. Transferases in Polymer Chemistry

    NARCIS (Netherlands)

    van der Vlist, Jeroen; Loos, Katja; Palmans, ARA; Heise, A

    2010-01-01

    Transferases are enzymes that catalyze reactions in which a group is transferred from one compound to another. This makes these enzymes ideal catalysts for polymerization reactions. In nature, transferases are responsible for the synthesis of many important natural macromolecules. In synthetic polym

  19. Composite Films of Arabinoxylan and Fibrous Sepiolite: Morphological, Mechanical, and Barrier Properties

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Blomfeldt, J.O.; Hedenqvist, Mikael S.;

    2012-01-01

    in the arabinoxylan films and sepiolite fiber aggregation was not found. FT-IR spectroscopy provided some evidence for hydrogen bonding between sepiolite and arabinoxylan. Consistent with these findings, mechanical testing showed increases in film stiffness and strength with sepiolite addition and the effect of poly...

  20. Arabinoxylan activates Dectin-1 and modulates particulate beta-glucan-induced Dectin-1 activation

    NARCIS (Netherlands)

    Sahasrabudhe, Neha M.; Schols, Henk A.; Faas, Marijke M.; de Vos, Paul

    2016-01-01

    ScopeArabinoxylan is one of the most commonly consumed dietary fiber. Immunomodulation by arabinoxylan is documented but the mechanisms by which these immune-effects are accomplished are unknown. Methods and resultsBy applying reporter cell lines for Toll-like receptors (TLRs) and Dectin-1, we demon

  1. 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 enzy...

  2. Purification and Characterization of a Feruloyl Esterase from the Intestinal Bacterium Lactobacillus acidophilus

    OpenAIRE

    Wang, Xiaokun; Geng, Xin; Egashira, Yukari; Sanada, Hiroo

    2004-01-01

    Dietary ferulic acid (FA), a significant antioxidant substance, is currently the subject of extensive research. FA in cereals exists mainly as feruloylated sugar ester. To release FA from food matrices, it is necessary to cleave ester cross-linking by feruloyl esterase (FAE) (hydroxycinnamoyl esterase; EC 3.1.1.73). In the present study, the FAE from a human typical intestinal bacterium, Lactobacillus acidophilus, was isolated, purified, and characterized for the first time. The enzyme was pu...

  3. Impact of water extractable arabinoxylan from rye bran on the frozen steamed bread dough quality.

    Science.gov (United States)

    Wang, Pei; Tao, Han; Jin, Zhengyu; Xu, Xueming

    2016-06-01

    Impact of water extractable arabinoxylan from rye bran on frozen steamed bread dough quality was investigated in terms of the bread characteristics, ice crystallization, yeast activity as well as the gluten molecular weight distribution and glutenin macropolymer content in the present study. Results showed that water extractable arabinoxylan significantly improved bread characteristics during the 60-day frozen storage. Less water was crystallized in the water extractable arabinoxylan dough during storage, which could explain the alleviated yeast activity loss. For all the frozen dough samples, more soluble high molecular weight (Mw ≈ 91,000-688,000) and low molecular weight (Mw ≈ 91,000-16,000) proteins were derived from glutenin macropolymer depolymerization. Nevertheless, water extractable arabinoxylan dough developed higher glutenin macropolymer content with lowered level of soluble low molecular weight proteins throughout the storage. This study suggested water extractable arabinoxylan from rye bran had great potential to be served as an effective frozen steamed bread dough improver. PMID:26830568

  4. Water Extractable Arabinoxylan Aerogels Prepared by Supercritical CO2 Drying

    Directory of Open Access Journals (Sweden)

    Agustín Rascón-Chu

    2013-05-01

    Full Text Available Water extractable arabinoxylan (WEAX aerogels were prepared by extracting the solvent from the alcogels (WEAX hydrogels with an alcohol as the solvent with carbon dioxide under supercritical conditions. WEAX aerogels were characterized using scanning electron microscopy and adsorption and desorption nitrogen isotherms. The micrographs indicate a heterogeneous porous network structure in WEAX aerogel. Adsorption/desorption nitrogen isotherms of this material were type IV, which confirm that this material possess a mesoporous structure. WEAX aerogels rehydration capability was evaluated and the water absorption mechanism was determined. The WEAX aerogels water absorption mechanism was non-Fickian (n = 0.54.

  5. Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

    Science.gov (United States)

    Buksa, Krzysztof; Nowotna, Anna; Ziobro, Rafał

    2016-02-01

    The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention. PMID:26304439

  6. Application of cross-linked and hydrolyzed arabinoxylans in baking of model rye bread.

    Science.gov (United States)

    Buksa, Krzysztof; Nowotna, Anna; Ziobro, Rafał

    2016-02-01

    The role of water extractable arabinoxylan with varying molar mass and structure (cross-linked vs. hydrolyzed) in the structure formation of rye bread was examined using a model bread. Instead of the normal flour, the dough contained starch, arabinoxylan and protein, which were isolated from rye wholemeal. It was observed that the applied mixes of these constituents result in a product closely resembling typical rye bread, even if arabinoxylan was modified (by cross-linking or hydrolysis). The levels of arabinoxylan required for bread preparation depended on its modification and mix composition. At 3% protein, the maximum applicable level of poorly soluble cross-linked arabinoxylan was 3%, as higher amounts of this preparation resulted in an extensively viscous dough and diminished bread volume. On the other hand highly soluble, hydrolyzed arabinoxylan could be used at a higher level (6%) together with larger amounts of rye protein (3% or 6%). Further addition of arabinoxylan leads to excessive water absorption, resulting in a decreased viscosity of the dough during baking and insufficient gas retention.

  7. Molecular Features of Wheat Endosperm Arabinoxylan Inclusion in Functional Bread

    Directory of Open Access Journals (Sweden)

    Weili Li

    2013-06-01

    Full Text Available Arabinoxylan (AX is a major dietary fibre component found in a variety of cereals. Numerous health benefits of arabinoxylans have been reported to be associated with their solubility and molecular features. The current study reports the development of a functional bread using a combination of AX-enriched material (AEM and optimal commercial endoxylanase. The total AX content of bread was increased to 8.2 g per 100 g available carbohydrates. The extractability of AX in breads with and without endoxylanase was determined. The results demonstrate that water-extractable AX (WE-AX increased progressively through the bread making process. The application of endoxylanase also increased WE-AX content. The presence of 360 ppm of endoxylanase had positive effects on the bread characteristics in terms of bread volume and firmness by converting the water unextractable (WU-AX to WE-AX. In addition, the molecular weight (Mw distribution of the WE-AX of bread with and without endoxylanase was characterized by size-exclusion chromatography. The results show that as the portion of WE-AX increased, the amount of high Mw WE-AX (higher than 100 kDa decreased, whereas the amount of low Mw WE-AX (lower than 100 kDa increased from 33.2% to 44.2% through the baking process. The low Mw WE-AX further increased to 75.5% with the application of the optimal endoxylanase (360 ppm.

  8. Genotypic and Environmental Variations of Arabinoxylan Content and Endoxylanase Activity in Barley Grains

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-qin; XUE Da-wei; WU Fei-bo; ZHANG Guo-ping

    2013-01-01

    Arabinoxylan (AX) content in barley grains is an important quality determinant when barley is used as raw material of malt or beer production. The cultivar and environmental variations of total arabinoxylan (TAX), water extractable arabinoxylan (WEAX) and endoxylanase activity (EA) were investigated using eight barley cultivars growing at seven locations with diverse environmental conditions. The results showed that both barley cultivar and location significantly affected the TAX, WEAX and EA levels, but the variations of TAX content and EA were mainly attributed to cultivar, while the impact of location on WEAX content was greater than that of cultivar. Correlation analysis indicated that TAX was significantly correlated to WUAX.

  9. Effects of Wheat Bran Extract Containing Arabinoxylan Oligosaccharides on Gastrointestinal Parameters in Healthy Preadolescent Children

    NARCIS (Netherlands)

    Francois, Isabelle E. J. A.; Lescroart, Olivier; Veraverbeke, Wim S.; Marzorati, Massimo; Possemiers, Sam; Hamer, Henrike; Windey, Karen; Welling, Gjalt W.; Delcour, Jan A.; Courtin, Christophe M.; Verbeke, Kristin; Broekaert, Willem F.

    2014-01-01

    Objectives: We assessed whether wheat bran extract (WBE) containing arabinoxylan-oligosaccharides (AXOS) elicited a prebiotic effect and modulated gastrointestinal (GI) parameters in healthy preadolescent children upon consumption in a beverage. Methods: This double-blind randomized placebo-controll

  10. Expression of feruloyl esterase A from Aspergillus terreus and its application in biomass degradation.

    Science.gov (United States)

    Zhang, Shuai-Bing; Wang, Le; Liu, Yan; Zhai, Huan-Chen; Cai, Jing-Ping; Hu, Yuan-Sen

    2015-11-01

    Feruloyl esterases (FAEs) are key enzymes involved in the complete biodegradation of lignocelluloses, which could hydrolyze the ester bonds between hemicellulose and lignin. The coding sequence of a feruloyl esterase A (AtFaeA) was cloned from Aspergillus terreus and the recombinant AtFaeA was constitutively expressed in Pichia pastoris. The SDS-PAGE analysis of purified AtFaeA showed two protein bands owing to the different extent of glycosylation, and the recombinant AtFaeA had an optimum temperature of 50°C and an optimum pH of 5.0. The substrate utilization and primary sequence identity of AtFaeA demonstrated that it is a type-A feruloyl esterase. The hydrolysis of corn stalk and corncob by xylanase from Aspergillus niger could be significantly improved in concert with recombinant AfFaeA. PMID:26282562

  11. Structural Variation and Content of Arabinoxylans in Endosperm and Bran of Durum Wheat (Triticum turgidum L.).

    Science.gov (United States)

    Marcotuli, Ilaria; Hsieh, Yves S-Y; Lahnstein, Jelle; Yap, Kuok; Burton, Rachel Anita; Blanco, Antonio; Fincher, Geoffrey Bruce; Gadaleta, Agata

    2016-04-13

    Arabinoxylans are one group of dietary fiber components in cereal grains, and specific health benefits have been linked with their molecular fine structures and hence with physicochemical properties such as solubility in aqueous media. To characterize the fiber quality for functional foods, starchy endosperm and bran fractions from 11 durum wheat lines were analyzed for total and water-soluble arabinoxylans, (1,3;1,4)-β-glucan, and bound ferulic acid. The arabinoxylan contents ranged from 11 to 16.4% (w/w) in bran and from 1.5 to 1.8% in the starchy endosperm. Of the starchy endosperm arabinoxylans, 37% was soluble in water. No correlation was found between arabinoxylan content and bound ferulic acid in bran, although a relatively high level of this antioxidant was found in endosperm (38.3 μg/g endosperm flour). Enzymatic fingerprinting was performed to define the major fine structural features of arabinoxylans from both regions of the grain. Five major oligosaccharides released by xylanase hydrolysis were identified and characterized in the 11 durum lines. In addition, DP5, DP6, and DP7 oligosaccharides containing five, six, and seven pentosyl residues, respectively, were purified. PMID:27018210

  12. Characterization of (Glucurono)arabinoxylans from Oats Using Enzymatic Fingerprinting.

    Science.gov (United States)

    Tian, Lingmin; Gruppen, Harry; Schols, Henk A

    2015-12-23

    Cell wall material from whole oat grains was sequentially extracted to study the structural characteristics of individual arabinoxylan (AX) populations. Araf was singly substituted at both O-3 (mainly) and O-2 positions of Xylp, and no disubstitution of Xylp with Araf residues was found in oat AXs. Both highly substituted and sparsely substituted segments were found in AXs in Ba(OH)2 extracts, whereas AXs in 1 and 6 M NaOH extracts were rarely branched and easily aggregated. Both O-2-linked GlcA and 4-O-MeGlcA residues were present in oat AXs. A series of AX oligomers with galactose as a substituent was detected for the first time in oats. The present study suggested that the distribution of Araf was contiguous in oat AXs, different from the homogeneous distribution of Araf in wheat and barley AXs, which might result in different fermentation patterns in humans and animals.

  13. Kinetics of enzyme-catalyzed cross-linking of feruloylated arabinan from sugar beet

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz; Arnous, Anis; Holck, Jesper;

    2011-01-01

    the kinetics of HRP catalyzed cross-linking of FA esterified to α-(1,5)-linked arabinans are affected by the length of the arabinan chains carrying the feruloyl substitutions. The kinetics of the HRP-catalyzed cross-linking of four sets of arabinan samples from sugar beet pulp, having different molecular...... weights and hence different degrees of polymerization, were monitored by the disappearance of FA absorbance at 316 nm. MALDI-TOF/TOF-MS analysis confirmed that the sugar beet arabinans were feruloyl-substituted, and HPLC analysis verified that the amounts of diFAs increased when FA levels decreased...

  14. Enzymatic Glycosylation by Transferases

    DEFF Research Database (Denmark)

    Blixt, Klas Ola; Razi, Nahid

    2008-01-01

    . Glycosyltransferases are now playing a key role for in vitro synthesis of oligosaccharides and the bacterial genome are increasingly utilized for cloning and over expression of active transferases in glycosylation reactions. This chapter highlights the recent progress towards preparative synthesis of oligosaccharides...

  15. Continuous, packed-bed, enzymatic bioreactor production and stability of feruloyl soy glycerides

    Science.gov (United States)

    The synthesis of feruloyl soy glycerides was demonstrated on a pilot-scale (1 metric ton/year) in a continuous, four-column series, packed-bed, enzymatic bioreactor. Ethyl ferulate and soybean oil were combined and converted at 3.5 kg/d over Candida antartica lipase B immobilized on an acrylic rein ...

  16. 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...

  17. Respective importance of protein folding and glycosylation in the thermal stability of recombinant feruloyl esterase A

    NARCIS (Netherlands)

    Benoit, Isabelle; Asther, Michèle; Sulzenbacher, Gerlind; Record, Eric; Marmuse, Laurence; Parsiegla, Goetz; Gimbert, Isabelle; Asther, Marcel; Bignon, Christophe

    2006-01-01

    The thermal stability of four molecular forms (native, refolded, glycosylated, non-glycosylated) of feruloyl esterase A (FAEA) was studied. From the most to the least thermo-resistant, the four molecular species ranked as follows: (i) glycosylated form produced native, (ii) non-glycosylated form pro

  18. Overproduction of the Aspergillus niger feruloyl esterase for pulp bleaching application

    NARCIS (Netherlands)

    Record, E.; Asther, M.; Sigoillot, C.; Pagès, S.; Punt, P.J.; Delattre, M.; Haon, M.; Hondel, C.A.M.J.J. van den; Sigoillot, J.C.; Lesage-Meessen, L.; Asther, M.

    2003-01-01

    A well-known industrial fungus for enzyme production, Aspergillus niger, was selected to produce the feruloyl esterase FAEA by homologous overexpression for pulp bleaching application. The gpd gene promoter was used to drive FAEA expression. Changing the nature and concentration of the carbon source

  19. 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...

  20. Postprandial effects of test meals including concentrated arabinoxylan and whole grain rye in subjects with the metabolic syndrome

    DEFF Research Database (Denmark)

    Hartvigsen, M L; Lærke, H N; Bjørnshave, Ann;

    2014-01-01

    of digestible carbohydrate were as follows: semolina porridge added concentrated arabinoxylan (AX), rye kernels (RK) or concentrated arabinoxylan combined with rye kernels (AXRK) and semolina porridge as control (SE). A standard lunch was served 4 h after the test meals. Blood samples were drawn during a 6-h...

  1. Solvent-free enzymatic synthesis of feruloylated structured lipids by the transesterification of ethyl ferulate with castor oil.

    Science.gov (United States)

    Sun, Shangde; Zhu, Sha; Bi, Yanlan

    2014-09-01

    A novel enzymatic route of feruloylated structured lipids synthesis by the transesterification of ethyl ferulate (EF) with castor oil, in solvent-free system, was investigated. The transesterification reactions were catalysed by Novozym 435, Lipozyme RMIM, and Lipozyme TLIM, among which Novozym 435 showed the best catalysis performance. Effects of feruloyl donors, reaction variables, and ethanol removal on the transesterification were also studied. High EF conversion (∼100%) was obtained under the following conditions: enzyme load 20% (w/w, relative to the weight of substrates), reaction temperature 90 °C, substrate molar ratio 1:1 (EF/castor oil), 72 h, vacuum pressure 10 mmHg, and 200 rpm. Under these conditions, the transesterification product consisted of 62.6% lipophilic feruloylated structured lipids and 37.3% hydrophilic feruloylated lipids.

  2. Covalently Cross-Linked Arabinoxylans Films for Debaryomyces hansenii Entrapment

    Directory of Open Access Journals (Sweden)

    Ramsés González-Estrada

    2015-06-01

    Full Text Available In the present study, wheat water extractable arabinoxylans (WEAX were isolated and characterized, and their capability to form covalently cross-linked films in presence of Debaryomyces hansenii was evaluated. WEAX presented an arabinose to xylose ratio of 0.60, a ferulic acid and diferulic acid content of 2.1 and 0.04 µg∙mg−1 WEAX, respectively and a Fourier Transform Infra-Red (FT-IR spectrum typical of WEAX. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.6 dL∙g−1 and 440 kDa, respectively. The gelation of WEAX (1% w/v with and without D. hansenii (1 × 107 CFU∙cm−2 was rheologically investigated by small amplitude oscillatory shear. The entrapment of D. hansenii decreased gel elasticity from 1.4 to 0.3 Pa, probably by affecting the physical interactions between WEAX chains. Covalently cross-linked WEAX films containing D. hansenii were prepared by casting. Scanning electron microscopy images show that WEAX films containing D. hansenii were porous and consisted of granular-like and fibre microstructures. Average tensile strength, elongation at break and Young’s modulus values dropped when D. hansenii was present in the film. Covalently cross-lined WEAX containing D. hansenii could be a suitable as a functional entrapping film.

  3. Feruloylated and Nonferuloylated Arabino-oligosaccharides from Sugar Beet Pectin Selectively Stimulate the Growth of Bifidobacterium spp. in Human Fecal in Vitro Fermentations

    DEFF Research Database (Denmark)

    Holck, Jesper; Lorentzen, Andrea; Vigsnæs, Louise Kristine;

    2011-01-01

    The side chains of the rhamnogalacturonan I fraction in sugar beet pectin are particularly rich in arabinan moieties, which may be substituted with feruloyl groups. In this work the arabinan-rich fraction resulting from sugar beet pulp based pectin production was separated by Amberlite XAD...... hydrophobic interaction and membrane separation into four fractions based on feruloyl substitution and arabino-oligosaccharide chain length: short-chain (DP 2–10) and long-chain (DP 7–14) feruloylated and nonferuloylated arabino-oligosaccharides, respectively. HPAEC, SEC, and MALDI-TOF/TOF analyses...... of the fractions confirmed the presence of singly and doubly substituted feruloylated arabino-oligosaccharides in the feruloyl-substituted fractions. In vitro microbial fermentation by human fecal samples (n = 6 healthy human volunteers) showed a selective stimulation of bifidobacteria by both the feruloylated...

  4. Feruloyl esterases from Schizophyllum commune to treat food industry side-streams.

    Science.gov (United States)

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

    2016-11-01

    Agro-industrial side-streams are abundant and renewable resources of hydroxycinnamic acids with potential applications as antioxidants and preservatives in the food, health, cosmetic, and pharmaceutical industries. Feruloyl esterases (FAEs) from Schizophyllum commune were functionally expressed in Pichia pastoris with extracellular activities of 6000UL(-1). The recombinant enzymes, ScFaeD1 and ScFaeD2, released ferulic acid from destarched wheat bran and sugar beet pectin. Overnight incubation of coffee pulp released caffeic (>60%), ferulic (>80%) and p-coumaric acid (100%) indicating applicability for the valorization of food processing wastes and enhanced biomass degradation. Based on substrate specificity profiling and the release of diferulates from destarched wheat bran, the recombinant FAEs were characterized as type D FAEs. ScFaeD1 and ScFaeD2 preferably hydrolyzed feruloylated saccharides with ferulic acid esterified to the O-5 position of arabinose residues and showed an unprecedented ability to hydrolyze benzoic acid esters.

  5. Review on technological and scientific aspects of feruloyl esterases: A versatile enzyme for biorefining of biomass.

    Science.gov (United States)

    Gopalan, Nishant; Rodríguez-Duran, L V; Saucedo-Castaneda, G; Nampoothiri, K Madhavan

    2015-10-01

    With increasing focus on sustainable energy, bio-refining from lignocellulosic biomass has become a thrust area of research. With most of the works being focused on biofuels, significant efforts are also being directed towards other value added products. Feruloyl esterases (EC. 3.1.1.73) can be used as a tool for bio-refining of lignocellulosic material for the recovery and purification of ferulic acid and related hydroxycinnamic acids ubiquitously found in the plant cell wall. More and more genes coding for feruloyl esterases have been mined out from various sources to allow efficient enzymatic release of ferulic acid and allied hydroxycinnamic acids (HCAs) from plant-based biomass. A sum up on enzymatic extraction of HCAs and its recovery from less explored agro residual by-products is still a missing link and this review brushes up the achieved landmarks so far in this direction and also covers a detailed patent search on this biomass refining enzyme. PMID:26159377

  6. A new feruloyl amide derivative from the fruits of Tribulus terrestris.

    Science.gov (United States)

    Zhang, Xiaopo; Wei, Na; Huang, Jian; Tan, Yinfeng; Jin, Dejun

    2012-01-01

    A new feruloyl amide derivative, named tribulusamide C, was isolated from the fruits of Tribulus terrestris. Its structure was determined on the basis of spectroscopic analysis including IR, 1-D-, 2-D-NMR and HR-ESI-MS. The structure of tribulusamide C was characterised by a unit of pyrrolidine-2,5-dione, which distinguished it from other lignanamides previously isolated from the fruits of T. terrestris. PMID:22149942

  7. Cloning, expression and characterization of a feruloyl esterase C from Penicillium chrysogenum

    Institute of Scientific and Technical Information of China (English)

    LV Shan-shan; LI Gui-Iong; YANG Shao-Iong

    2016-01-01

    Objective: To clone feruloyl esterase gene C from Penicillium chrysogenum and characterize the general properties of the enzyme. Methods:The feruloyl esterase C gene was amplified by PCR based on the Penicillium chrysogenum feruloyl esterase C gene sequence and cloned into the expression vector pPIC9K, resulting the recombinant plasmid pPIC9K-PcfaeC. The recombiant plasmid was linerized and transformed into P. pastoris by electroporation. The transformants was screened based on the transparent zone technology. The screened transformants was then induced by methanol. the enzymatic properties of the protein were then measured. Results:SDS-PAGE analysis showed that the molecular mass of the enzyme was about 30 kD. The length of the gene was 762 bp. It comprised one open reading framwork(ORF) and annotated to encode 249 amino acid. The optimal temperature and pH was found to be 40℃and 6, respectively. Moreover, the recombinant enzyme was stable at 40-50℃and pH 5-7. Conclusion:The enzyme successfully expressed in P. pastoris could laid theoretical foundation in food, fodder and paper making industry.

  8. Different human gut models reveal the distinct fermentation patterns of arabinoxylan versus inulin

    NARCIS (Netherlands)

    Abbeele, P. van den; Venema, K.; Wiele, T. van de; Verstraete, W.; Possemiers, S.

    2013-01-01

    Different in vitro models have been developed to assess how food compounds affect the human gut microbiota. Using two such models (SHIME(R) and TIM-2), we compared how long-chain arabinoxylan (LC-AX), a wheat-derived potentially prebiotic fiber, and inulin (IN), a well-established prebiotic compound

  9. Consumption of Breads Containing In Situ-Produced Arabinoxylan Oligosaccharides Alters Gastrointestinal Effects in Healthy Volunteers

    NARCIS (Netherlands)

    Damen, Bram; Cloetens, Lieselotte; Broekaert, Willem F.; Francois, Isabelle; Lescroart, Olivier; Trogh, Isabel; Arnaut, Filip; Welling, Gjalt W.; Wijffels, Jan; Delcour, Jan A.; Verbeke, Kristin; Courtin, Christophe M.

    2012-01-01

    Arabinoxylan oligosaccharides (AXOS) are studied as food compounds with prebiotic potential. Here, the impact of consumption of breads with in situ-produced AXOS on intestinal fermentation and overall gastrointestinal characteristics was evaluated in a completely randomized, double-blind, controlled

  10. Debranching of soluble wheat arabinoxylan dramatically enhances recalcitrant binding to cellulose

    DEFF Research Database (Denmark)

    Selig, Michael J.; Thygesen, Lisbeth G.; Felby, Claus;

    2015-01-01

    The presence of xylan is a detriment to the enzymatic saccharification of cellulose in lignocelluloses. The inhibition of the processive cellobiohydrolase Cel7A by soluble wheat arabinoxylan is shown here to increase by 50 % following enzymatic treatment with a commercially-purified α-l-arabinofu......The presence of xylan is a detriment to the enzymatic saccharification of cellulose in lignocelluloses. The inhibition of the processive cellobiohydrolase Cel7A by soluble wheat arabinoxylan is shown here to increase by 50 % following enzymatic treatment with a commercially-purified α......-l-arabinofuranosidase. The enhanced inhibitory effect was shown by T2 relaxation time measurements via low field NMR to coincide with an increasing degree of constraint put on the water in xylan solutions. Furthermore, quartz crystal micro-balance with dissipation experiments showed that α-l-arabinofuranosidase treatment...... considerably increased the rate and rigidity of arabinoxylan mass association with cellulose. These data also suggest significant xylan–xylan adlayer formation occurs following initial binding of debranched arabinoxylan. From this, we speculate the inhibitory effects of xylan to cellulases may result from...

  11. Films from spruce galactoglucomannan blended with poly(vinyl alcohol), corn arabinoxylan and konjac glucomannan

    Science.gov (United States)

    The improvement of mechanical properties of spruce galactoglucomannan (GGM)-based films was sought by blending GGM with each of poly(vinyl alcohol) (PVOH), corn arabinoxylan (cAX), and konjac glucomannan (KGM). The blend ratios were 3:1, 1:1, and 1:3(w/w), and in addition films were made from each o...

  12. Enzyme kinetics and identification of the rate-limiting step of enzymatic arabinoxylan degradation

    DEFF Research Database (Denmark)

    Rasmussen, Louise Enggaard; Xu, Cheng; Sørensen, Jens;

    2012-01-01

    than AFAn, but with respect to the xylose release, AFAn – as expected – exhibited a better synergistic effect than AFBa with β-xylosidase. This synergistic effect with AFAn was estimated to increase the number of β-xylosidase catalyzed cuts from ∼3 (with β-xylosidase alone) to ∼7 in each arabinoxylan...

  13. Hydroxycinnamic acid bound arabinoxylans from millet brans-structural features and antioxidant activity.

    Science.gov (United States)

    Bijalwan, Vandana; Ali, Usman; Kesarwani, Atul Kumar; Yadav, Kamalendra; Mazumder, Koushik

    2016-07-01

    Hydroxycinnamic acid bound arabinoxylans (HCA-AXs) were extracted from brans of five Indian millet varieties and response surface methodology was used to optimize the extraction conditions. The optimal condition to obtain highest yield of millet HCA-AXs was determined as follows: time 61min, temperature 66°C, ratio of solvent to sample 12ml/g. Linkage analysis indicated that hydroxycinnamic acid bound arabinoxylan from kodo millet (KM-HCA-AX) contained comparatively low branched arabinoxylan consisting of 14.6% mono-substituted, 1.2% di-substituted and 41.2% un-substituted Xylp residues. The HPLC analysis of millet HCA-AXs showed significant variation in the content of three major bound hydroxycinnamic acids (caffeic, p-coumaric and ferulic acid). The antioxidant activity of millet HCA-AXs were evaluated using three in vitro assay methods (DPPH, FRAP and β-carotene linoleate emulsion assays) which suggested both phenolic acid composition and structural characteristics of arabinoxylans could be correlated to their antioxidant potential, the detailed structural analysis revealed that low substituted KM-HCA-AX exhibited relatively higher antioxidant activity compared to other medium and highly substituted HCA-AXs from finger (FM), proso (PM), barnyard (BM) and foxtail (FOXM) millet. PMID:27050114

  14. Optimization of reaction conditions for enzymatic viscosity reduction and hydrolysis of wheat arabinoxylan in an industrial ethanol fermentation residue

    DEFF Research Database (Denmark)

    Sørensen, H.R.; Pedersen, S.; Meyer, Anne Boye Strunge

    2006-01-01

    This study examined enzyme-catalyzed viscosity reduction and evaluated the effects of substrate dry matter concentration on enzymatic degradation of arabinoxylan in a fermentation residue, "vinasse", resulting from industrial ethanol manufacture on wheat. Enzymatic catalysis was accomplished...... of enzyme-catalyzed hydrolysis of arabinoxylan, beta-glucan, and cellulose. In designed response surface experiments, the optimal enzyme reaction conditions with respect to pH and temperature of the vinasse, the vinasse supernatant (mainly soluble material), and the vinasse sediment (mainly insoluble...

  15. Contribution of Disulfide Bridges to the Thermostability of a Type A Feruloyl Esterase from Aspergillus usamii

    OpenAIRE

    Xin Yin; Die Hu; Jian-Fang Li; Yao He; Tian-Di Zhu; Min-Chen Wu

    2015-01-01

    The contribution of disulfide bridges to the thermostability of a type A feruloyl esterase (AuFaeA) from Aspergillus usamii E001 was studied by introducing an extra disulfide bridge or eliminating a native one from the enzyme. MODIP and DbD, two computational tools that can predict the possible disulfide bridges in proteins for thermostability improvement, and molecular dynamics (MD) simulations were used to design the extra disulfide bridge. One residue pair A126-N152 was chosen, and the res...

  16. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    OpenAIRE

    Chi Chen Lin; Hua Han Chen; Yu Kuo Chen; Hung Chia Chang; Ping Yi Lin; I-Hong Pan; Der-Yuan Chen; Chuan Mu Chen; Su Yi Lin

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with ...

  17. Arabinoxylan Oligosaccharide Hydrolysis by Family 43 and 51 Glycosidases from Lactobacillus brevis DSM 20054

    OpenAIRE

    Michlmayr, Herbert; Hell, Johannes; Lorenz, Cindy; Böhmdorfer, Stefan; Rosenau, Thomas; Kneifel, Wolfgang

    2013-01-01

    Due to their potential prebiotic properties, arabinoxylan-derived oligosaccharides [(A)XOS] are of great interest as functional food and feed ingredients. While the (A)XOS metabolism of Bifidobacteriaceae has been extensively studied, information regarding lactic acid bacteria (LAB) is still limited in this context. The aim of the present study was to fill this important gap by characterizing candidate (A)XOS hydrolyzing glycoside hydrolases (GHs) identified in the genome of Lactobacillus bre...

  18. Interactions of arabinoxylan and (1,3)(1,4)-β-glucan with cellulose networks.

    Science.gov (United States)

    Mikkelsen, Deirdre; Flanagan, Bernadine M; Wilson, Sarah M; Bacic, Antony; Gidley, Michael J

    2015-04-13

    To identify interactions of relevance to the structure and properties of the primary cell walls of cereals and grasses, we used arabinoxylan and (1,3)(1,4)-β-glucan, major polymers in cereal/grass primary cell walls, to construct composites with cellulose produced by Gluconacetobacter xylinus. Both polymers associated prolifically with cellulose without becoming rigid or altering the nature or extent of cellulose crystallinity. Mechanical properties were modestly affected compared with xyloglucan or pectin (characteristic components of nongrass primary cell walls) composites with cellulose. In situ depletion of arabinoxylan arabinose side chains within preformed cellulose composites resulted in phase separation, with only limited enhancement of xylan-cellulose interactions. These results suggest that arabinoxylan and (1 → 3)(1 → 4)-β-d-glucan are not functional homologues for either xyloglucan or pectin in the way they interact with cellulose networks. Association of cell-wall polymers with cellulose driven by entropic amelioration of high energy cellulose/water interfaces should be considered as a third type of interaction within cellulose-based cell walls, in addition to molecular binding (enthalpic driving force) exhibited by, for example, xyloglucans or mannans, and interpenetrating networks based on, for example, pectins. PMID:25756836

  19. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

    Science.gov (United States)

    Reem, Nathan T.; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A.; Bellincampi, Daniela; Zabotina, Olga A.

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens. PMID:27242834

  20. Feruloyl esterases from Schizophyllum commune to treat food industry side-streams.

    Science.gov (United States)

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

    2016-11-01

    Agro-industrial side-streams are abundant and renewable resources of hydroxycinnamic acids with potential applications as antioxidants and preservatives in the food, health, cosmetic, and pharmaceutical industries. Feruloyl esterases (FAEs) from Schizophyllum commune were functionally expressed in Pichia pastoris with extracellular activities of 6000UL(-1). The recombinant enzymes, ScFaeD1 and ScFaeD2, released ferulic acid from destarched wheat bran and sugar beet pectin. Overnight incubation of coffee pulp released caffeic (>60%), ferulic (>80%) and p-coumaric acid (100%) indicating applicability for the valorization of food processing wastes and enhanced biomass degradation. Based on substrate specificity profiling and the release of diferulates from destarched wheat bran, the recombinant FAEs were characterized as type D FAEs. ScFaeD1 and ScFaeD2 preferably hydrolyzed feruloylated saccharides with ferulic acid esterified to the O-5 position of arabinose residues and showed an unprecedented ability to hydrolyze benzoic acid esters. PMID:27566510

  1. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens.

    Science.gov (United States)

    Reem, Nathan T; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A; Bellincampi, Daniela; Zabotina, Olga A

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens.

  2. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens

    Directory of Open Access Journals (Sweden)

    Nathan T Reem

    2016-05-01

    Full Text Available The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity and function remains unclear. Modifications of cell wall composition can induce plant responses known as Cell Wall Integrity control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, increased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant cell wall integrity, which contributes to plant resistance to necrotrophic pathogens.

  3. Decreased Polysaccharide Feruloylation Compromises Plant Cell Wall Integrity and Increases Susceptibility to Necrotrophic Fungal Pathogens.

    Science.gov (United States)

    Reem, Nathan T; Pogorelko, Gennady; Lionetti, Vincenzo; Chambers, Lauran; Held, Michael A; Bellincampi, Daniela; Zabotina, Olga A

    2016-01-01

    The complexity of cell wall composition and structure determines the strength, flexibility, and function of the primary cell wall in plants. However, the contribution of the various components to cell wall integrity (CWI) and function remains unclear. Modifications of cell wall composition can induce plant responses known as CWI control. In this study, we used transgenic expression of the fungal feruloyl esterase AnFAE to examine the effect of post-synthetic modification of Arabidopsis and Brachypodium cell walls. Transgenic Arabidopsis plants expressing AnFAE showed a significant reduction of monomeric ferulic acid, decreased amounts of wall-associated extensins, and increased susceptibility to Botrytis cinerea, compared with wild type. Transgenic Brachypodium showed reductions in monomeric and dimeric ferulic acids and increased susceptibility to Bipolaris sorokiniana. Upon infection, transgenic Arabidopsis and Brachypodium plants also showed increased expression of several defense-related genes compared with wild type. These results demonstrate a role, in both monocot and dicot plants, of polysaccharide feruloylation in plant CWI, which contributes to plant resistance to necrotrophic pathogens. PMID:27242834

  4. Feruloyl esterases as a tool for the release of phenolic compounds from agro-industrial by-products

    NARCIS (Netherlands)

    Benoit, Isabelle; Navarro, David; Marnet, Nathalie; Rakotomanomana, Nnjara; Lesage-Meessen, Laurence; Sigoillot, Jean-Claude; Asther, Marcel; Asther, Michèle

    2006-01-01

    Agro-industrial by-products are a potential source of added-value phenolic acids with promising applications in the food and pharmaceutical industries. Here two purified feruloyl esterases from Aspergillus niger, FAEA and FAEB were tested for their ability to release phenolic acids such as caffeic a

  5. Design and production in Aspergillus niger of a chimeric protein associating a fungal feruloyl esterase and a clostridial dockerin domain

    NARCIS (Netherlands)

    Levasseur, A.; Pagès, S.; Fierobe, H.-P.; Navarro, D.; Punt, P.; Belaïch, J.-P.; Asther, M.; Record, E.

    2004-01-01

    A chimeric enzyme associating feruloyl esterase A (FAEA) from Aspergilhis niger and dockerin from Clostridium thermocellum was produced in A. niger. A completely truncated form was produced when the dockerin domain was located downstream of the FAEA (FAEA-Doc), whereas no chimeric protein was produc

  6. Novel feruloyl esterase from Lactobacillus fermentum NRRL B-1932 and analysis of the recombinant enzyme produced in Escherichia coli.

    Science.gov (United States)

    Using agar plates containing ethyl ferulate as the sole carbon source, 33 Lactobacillus strains were screened for feruloyl esterase (FE) activity. Among a dozen species showing a clearing zone on the opaque plate containing ethyl ferulate, Lactobacillus fermentum NRRL B-1932 demonstrated the stronge...

  7. Combining substrate specificity analysis with support vector classifiers reveals feruloyl esterase as a phylogenetically informative protein group

    DEFF Research Database (Denmark)

    Olivares Hernandez, Roberto; Sunner, Hampus; Frisvad, Jens Christian;

    2010-01-01

    Background Our understanding of how fungi evolved to develop a variety of ecological niches, is limited but of fundamental biological importance. Specifically, the evolution of enzymes affects how well species can adapt to new environmental conditions. Feruloyl esterases (FAEs) are enzymes able...

  8. Glutathione transferases and neurodegenerative diseases.

    Science.gov (United States)

    Mazzetti, Anna Paola; Fiorile, Maria Carmela; Primavera, Alessandra; Lo Bello, Mario

    2015-03-01

    There is substantial agreement that the unbalance between oxidant and antioxidant species may affect the onset and/or the course of a number of common diseases including Parkinson's and Alzheimer's diseases. Many studies suggest a crucial role for oxidative stress in the first phase of aging, or in the pathogenesis of various diseases including neurological ones. Particularly, the role exerted by glutathione and glutathione-related enzymes (Glutathione Transferases) in the nervous system appears more relevant, this latter tissue being much more vulnerable to toxins and oxidative stress than other tissues such as liver, kidney or muscle. The present review addresses the question by focusing on the results obtained by specimens from patients or by in vitro studies using cells or animal models related to Parkinson's and Alzheimer's diseases. In general, there is an association between glutathione depletion and Parkinson's or Alzheimer's disease. In addition, a significant decrease of glutathione transferase activity in selected areas of brain and in ventricular cerebrospinal fluid was found. For some glutathione transferase genes there is also a correlation between polymorphisms and onset/outcome of neurodegenerative diseases. Thus, there is a general agreement about the protective effect exerted by glutathione and glutathione transferases but no clear answer about the mechanisms underlying this crucial role in the insurgence of neurodegenerative diseases.

  9. Effects of a Bioavailable Arabinoxylan-enriched White Bread Flour on Postprandial Glucose Response in Normoglycemic Subjects.

    Science.gov (United States)

    Giulia Falchi, Anna; Grecchi, Ilaria; Muggia, Chiara; Palladini, Giuseppina; Perlini, Stefano

    2016-11-01

    The beneficial effects of soluble fibers on carbohydrate metabolism are well documented. In this regard, we tested an arabinoxylan-enriched white bread flour, obtained by a patented process by which the bran extracted from the milling process is enzymatically hydrolyzed in order to separate the soluble fraction fiber from the insoluble fiber. We recruited 24 healthy normoglycemic volunteers [Age 34-61 ± 12.5 y; Body Mass Index (BMI) 22.1 ± 2.5 kg/m(2); Waist circumference (WC) 84.43 ± 8.0 cm; Fat Mass (FM) 22.7 ± 8.0%] attending the Dietetics Outpatient Clinic of the Internal Medicine Department at IRCCS Policlinico S. Matteo Foundation, University of Pavia, Pavia, Italy. Subjects acutely consumed arabinoxylan-enriched white bread (weight: 100 g) or isoenergetic control breads, in a double-blind crossover study design. Plasma glucose levels were measured just before bread administration and 30 minutes afterwards. The 30-minute peak postprandial glucose concentrations after arabinoxylan-enriched meals were significantly lower than after the control meal (107±4.6 mg/dL vs. 121 ± 5.2 mg/dL; p < 0.05). The here-reported results show how postprandial glucose responses were improved by ingestion of the arabinoxylan-enriched meal. Further studies are needed to clarify whether daily consumption of arabinoxylan-enriched bread will benefit patients with type 2 diabetes mellitus. PMID:27049812

  10. Production of Feruloyl Esterase from Aspergillus niger by Solid-State Fermentation on Different Carbon Sources

    Directory of Open Access Journals (Sweden)

    Shiyi Ou

    2011-01-01

    Full Text Available A mixture of wheat bran with maize bran as a carbon source and addition of (NH4SO4 as nitrogen source was found to significantly increase production of feruloyl esterase (FAE enzyme compared with wheat bran as a sole carbon and nitrogen source. The optimal conditions in conical flasks were carbon source (30 g to water 1 : 1, maize bran to wheat bran 1 : 2, (NH4SO4 1.2 g and MgSO4 70 mg. Under these conditions, FAE activity was 7.68 mU/g. The FAE activity on the mixed carbon sources showed, high activity against the plant cell walls contained in the cultures.

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

    DEFF Research Database (Denmark)

    Abang Zaidel, Dayang Norulfairuz

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

  12. Extraction and chemical characterization of rye arabinoxylan and the effect of β-glucan on the mechanical and barrier properties of cast arabinoxylan films

    DEFF Research Database (Denmark)

    Sárossy, Zsuzsa; Tenkanen, Maija; Pitkänen, Leena;

    2013-01-01

    . Addition of BG to the purified WE-AX resulted in an increase in the tensile strength and elongation at break of the films. In contrast, the presence of BG had no clear effect on the oxygen permeability of the films. Both pure rye WE-AX and pure BG films showed excellent oxygen barrier properties (between 0.......9 and 1.0 cm3 mm/m2 d kPa). However, the water vapor permeability increased with addition of increasing amounts of BG to WE-AX. To our knowledge, this is the first study on the effect of β-glucans on the material and permeability properties of arabinoxylan-based films. © 2012 Elsevier Ltd. All rights...

  13. In vitro fermentation of arabinoxylan oligosaccharides and low molecular mass arabinoxylans with different structural properties from wheat (Triticum aestivum L.) bran and psyllium (Plantago ovata Forsk) seed husk.

    Science.gov (United States)

    Pollet, Annick; Van Craeyveld, Valerie; Van de Wiele, Tom; Verstraete, Willy; Delcour, Jan A; Courtin, Christophe M

    2012-02-01

    Ball milling was used for producing complex arabinoxylan oligosaccharides (AXOS) and low molecular mass arabinoxylans (AX) from wheat bran, pericarp-enriched wheat bran, and psyllium seed husk. The arabinose to xylose ratio of the samples produced varied between 0.14 and 0.92, and their average degree of polymerization (avDP) ranged between 42 and 300. Their fermentation for 48 h in an in vitro system using human colon suspensions was compared to enzymatically produced wheat bran AXOS with an arabinose to xylose ratio of 0.22 and 0.34 and an avDP of 4 and 40, respectively. Degrees of AXOS fermentation ranged from 28% to 50% and were lower for the higher arabinose to xylose ratio and/or higher avDP materials. Arabinose to xylose ratios of the unfermented fractions exceeded those of their fermented counterparts, indicating that molecules less substituted with arabinose were preferably fermented. Xylanase, arabinofuranosidase, and xylosidase activities increased with incubation time. Enzyme activities in the samples containing psyllium seed husk AX or psyllium seed husk AXOS were generally higher than those in the wheat bran AXOS preparations. Fermentation gave rise to unbranched short-chain fatty acids. Concentrations of acetic, propionic, and butyric acids increased to 1.9-2.6, 1.9-2.8, and 1.3-2.0 times their initial values, respectively, after 24 h incubation. Results show that the human intestinal microbiota can at least partially use complex AXOS and low molecular mass AX. The tested materials are thus interesting physiologically active carbohydrates. PMID:22224418

  14. Comparison of different twin-screw extraction conditions for the production of arabinoxylans.

    Science.gov (United States)

    Jacquemin, Leslie; Mogni, Assad; Zeitoun, Rawan; Guinot, Cécile; Sablayrolles, Caroline; Saulnier, Luc; Pontalier, Pierre-Yves

    2015-02-13

    The aim of this article is to compare two different sets of optimal conditions for twin-screw extraction of xylans and define their influence on the purification steps, combining ultrafiltration and industrial chromatography. Two xylan extracts were obtained by twin-screw extrusion of straw and bran. Condition 1 used a high straw/bran ratio (equal to 6) and high sodium hydroxide content, and condition 2 used a lower straw/bran ratio (equal to 2) and low sodium hydroxide content. Arabinoxylan extraction yields are slightly higher for conditions with low straw content (5.1% versus 4.4%). Nevertheless, these recovery yields remain between 9% and 10%. Ultrafiltration is as efficient as evaporation for polysaccharide concentration, with lower energy consumption, but also demineralizes the solution. The combination of ultrafiltration and chromatography gives partial purification of the extract with a final arabinoxylan purity ranging from 16% to 26%. This is slightly higher than by direct precipitation, but limited because all the large molecules such as proteins and lignins were retained by ultrafiltration.

  15. Comparison of different twin-screw extraction conditions for the production of arabinoxylans.

    Science.gov (United States)

    Jacquemin, Leslie; Mogni, Assad; Zeitoun, Rawan; Guinot, Cécile; Sablayrolles, Caroline; Saulnier, Luc; Pontalier, Pierre-Yves

    2015-02-13

    The aim of this article is to compare two different sets of optimal conditions for twin-screw extraction of xylans and define their influence on the purification steps, combining ultrafiltration and industrial chromatography. Two xylan extracts were obtained by twin-screw extrusion of straw and bran. Condition 1 used a high straw/bran ratio (equal to 6) and high sodium hydroxide content, and condition 2 used a lower straw/bran ratio (equal to 2) and low sodium hydroxide content. Arabinoxylan extraction yields are slightly higher for conditions with low straw content (5.1% versus 4.4%). Nevertheless, these recovery yields remain between 9% and 10%. Ultrafiltration is as efficient as evaporation for polysaccharide concentration, with lower energy consumption, but also demineralizes the solution. The combination of ultrafiltration and chromatography gives partial purification of the extract with a final arabinoxylan purity ranging from 16% to 26%. This is slightly higher than by direct precipitation, but limited because all the large molecules such as proteins and lignins were retained by ultrafiltration. PMID:25458276

  16. Crystallization and preliminary X-ray analysis of a novel halotolerant feruloyl esterase identified from a soil metagenomic library

    International Nuclear Information System (INIS)

    A novel feruloyl esterase (EstF27) identified from a soil metagenomic library has been crystallized and a complete data set was collected from a single cooled crystal using an in-house X-ray source. Feruloyl esterase cleaves the ester linkage formed between ferulic acid and polysaccharides in plant cell walls and thus has wide potential industrial applications. A novel feruloyl esterase (EstF27) identified from a soil metagenomic library was crystallized and a complete data set was collected from a single cooled crystal using an in-house X-ray source. The crystal diffracted to 2.9 Å resolution and belonged to space group P212121, with unit-cell parameters a = 94.35, b = 106.19, c = 188.51 Å, α = β = γ = 90.00°. A Matthews coefficient of 2.55 Å3 Da−1, with a corresponding solvent content of 51.84%, suggested the presence of ten protein subunits in the asymmetric unit

  17. Arabinoxylans and inulin differentially modulate the mucosal and luminal gut microbiota and mucin-degradation in humanized rats

    NARCIS (Netherlands)

    Van den Abbeele, Pieter; Gérard, Philippe; Rabot, Sylvie; Bruneau, Aurélia; El Aidy, Sahar; Derrien, Muriel; Kleerebezem, Michiel; Zoetendal, Erwin G; Smidt, Hauke; Verstraete, Willy; Van de Wiele, Tom; Possemiers, Sam

    2011-01-01

    The endogenous gut microbiota affects the host in many ways. Prebiotics should favour beneficial intestinal microbes and thus improve host health. In this study, we investigated how a novel class of potential prebiotic long-chain arabinoxylans (LC-AX) and the well-established prebiotic inulin (IN) m

  18. Genotype and environment variation for arabinoxylans in hard winter and spring wheats of the U.S. Pacific Northwest.

    Science.gov (United States)

    The development of high quality wheat (Triticum aestivum L.) varieties depends on a thorough understanding of the constituents of grain, and their variation due to genetics and environment. Arabinoxylans (pentosans) are key constituents of wheat grain and have broad and far-reaching influences on m...

  19. Effects of arabinoxylan-oligosaccharides (AXOS) on juvenile Siberian sturgeon (Acipenser baerii) performance, immune responses and gastrointestinal microbial community

    NARCIS (Netherlands)

    Geraylou, Z.; Souffreau, C.; Rurangwa, E.; Hondt, D' S.; Callewaert, L.; Courtin, C.M.; Delcour, J.A.; Buyse, J.; Ollevier, F.

    2012-01-01

    Arabinoxylan-oligosaccharides (AXOS) are a newly discovered class of candidate prebiotics that exert different properties depending on their structure. In this study the effects of two different structures of AXOS, namely AXOS-32-0.30 (average degree of polymerization: 32, average degree of substitu

  20. Production and partial characterization of arabinoxylan-degrading enzymes by Penicillium brasilianum under solid-state fermentation

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Granouillet, P.; Olsson, Lisbeth

    2006-01-01

    The production of a battery of arabinoxylan-degrading enzymes by the fungus Penicillium brasilianum grown on brewer's spent grain (BSG) under solid-state fermentation was investigated. Initial moisture content, initial pH, temperature, and nitrogen source content were optimized to achieve maximum...

  1. Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium

    Science.gov (United States)

    Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively impact immune status and prevent colonization and shedding in Salmonell...

  2. Feruloylated Oligosaccharides from Maize Bran Modulated the Gut Microbiota in Rats.

    Science.gov (United States)

    Ou, Juan-Ying; Huang, Jun-Qing; Song, Yuan; Yao, Sheng-Wen; Peng, Xi-Chun; Wang, Ming-Fu; Ou, Shi-Yi

    2016-06-01

    Corn bran is a byproduct produced from corn milling; it is rich in ferulic acid and hemicellulose. In this research, the effects of feruloylated oligosaccharides (FOs) from maize bran on the microbial diversity and profiles in rat feces were investigated through 16S rRNA sequencing. FOs significantly increased bacterial richness and diversity compared with the control and xylooligosaccharides (XOS) alone. In comparison with the control group and the group administrated with XOS, FOs orally administered at 300 mg/kg increased OTU in feces by 57.0 and 24.8 %, and Chao value by 93.4 and 37.6 %, respectively. FOs also influenced obesity- and diabetes-associated bacteria. Oral administration of FOs at 300 mg/kg decreased the ratio of Firmicutes to Bacteroidetes from 477.7:1 to 55.1:1; greatly increased the reads of bacteria that were previously found resistant against diabetes in rats, such as Actinobacteria, Bacteroides, and Lactobacillus; whereas decreased diabetes-prone bacteria, such as Clostridium and Firmicutes. PMID:27165128

  3. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    Directory of Open Access Journals (Sweden)

    Chi Chen Lin

    2014-04-01

    Full Text Available This work presents the effects of feruloylated oligosaccharides (FOs of rice bran on murine bone marrow-derived dendritic cells (BMDCs and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4 or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination.

  4. Rice bran feruloylated oligosaccharides activate dendritic cells via Toll-like receptor 2 and 4 signaling.

    Science.gov (United States)

    Lin, Chi Chen; Chen, Hua Han; Chen, Yu Kuo; Chang, Hung Chia; Lin, Ping Yi; Pan, I-Hong; Chen, Der-Yuan; Chen, Chuan Mu; Lin, Su Yi

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs) and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination. PMID:24762969

  5. Glutathione transferases: a structural perspective.

    Science.gov (United States)

    Oakley, Aaron

    2011-05-01

    The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and noncatalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs, and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed.

  6. pH catalyzed pretreatment of corn bran for enhanced enzymatic arabinoxylan degradation

    DEFF Research Database (Denmark)

    Agger, Jane; Johansen, Katja Salomon; Meyer, Anne S.

    2011-01-01

    Corn bran is mainly made up of the pericarp of corn kernels and is a byproduct stream resulting from the wet milling step in corn starch processing. Through statistic modeling this study examined the optimization of pretreatment of corn bran for enzymatic hydrolysis. A low pH pretreatment (pH 2......, 150°C, 65min) boosted the enzymatic release of xylose and glucose and maximized biomass solubilization. With more acidic pretreatment followed by enzymatic hydrolysis the total xylose release was maximized (at pH 1.3) reaching ∼50% by weight of the original amount present in destarched corn bran...... of xylose was significantly correlated to the total release of arabinose, indicating that the degree of arabinosyl-substitutions on the xylan backbone is an essential parameter for enzymatic hydrolysis of corn bran arabinoxylan....

  7. 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...... been sequenced, its carbohydrate esterases are not annotated yet. We applied peptide pattern recognition (PPR) tool for sequence analysis of the C. thermophilum genome, and 11 carbohydrate esterase genes were discovered. Furthermore, we cloned and heterologously expressed two putative acetyl xylan...... esterase genes, CtAxeA and CtAxeB, in Pichia pastoris. The recombinant proteins, rCtAxeA and rCtAxeB, released acetic acids from p-nitrophenyl acetate and water-insoluble wheat arabinoxylan. These results indicate that CtAxeA and CtAxeB are true acetyl xylan esterases. For both recombinant esterases, over...

  8. Resistant starch and arabinoxylan augment SCFA absorption, but affect postprandial glucose and insulin responses differently

    DEFF Research Database (Denmark)

    Ingerslev, Anne Krog; Theil, Peter Kappel; Hedemann, Mette Skou;

    2014-01-01

    adaptation to each diet. The pigs were fed a low DF western style control diet (WSD) and two high DF diets; an arabinoxylan (AXD) and a resistant starch (RSD) enriched diet. The NPF of insulin was lower (P = 0.04) in AXD fed pigs (4.6 nmol/h) compared to RSD fed pigs (10.5 nmol/h), despite the lowest NPF......The effects of increased colonic fermentation of dietary fibres (DF) on net portal flux (NPF) of carbohydrate-derived metabolites (glucose, SCFA and especially butyrate), hormones (insulin, C-peptide, GLP-1, GIP) and NEFA were studied in a healthy catheterised pig model. Six 59 ± 3.8 kg pigs were...... of glucose was observed in RSD fed pigs (203 mmol/h, P = 0.02). The NPF of total SCFA, acetate, propionate, and butyrate were high, intermediate, and low (P

  9. Application of model bread baking in the examination of arabinoxylan-protein complexes in rye bread.

    Science.gov (United States)

    Buksa, Krzysztof

    2016-09-01

    The changes in molecular mass of arabinoxylan (AX) and protein caused by bread baking process were examined using a model rye bread. Instead of the normal flour, the dough contained starch, water-extractable AX and protein which were isolated from rye wholemeal. From the crumb of selected model breads, starch was removed releasing AX-protein complexes, which were further examined by size exclusion chromatography. On the basis of the research, it was concluded that optimum model mix can be composed of 3-6% AX and 3-6% rye protein isolate at 94-88% of rye starch meaning with the most similar properties to low extraction rye flour. Application of model rye bread allowed to examine the interactions between AX and proteins. Bread baked with a share of AX, rye protein and starch, from which the complexes of the highest molar mass were isolated, was characterized by the strongest structure of the bread crumb. PMID:27185141

  10. Impact of wheat flour-associated endoxylanases on arabinoxylan in dough after mixing and resting.

    Science.gov (United States)

    Dornez, Emmie; Gebruers, Kurt; Cuyvers, Sven; Delcour, Jan A; Courtin, Christophe M

    2007-08-22

    The impact of varying levels of endoxylanase activity in wheat flour on arabinoxylan (AX) in mixed and rested dough was studied using eight industrially milled wheat flour fractions with varying endoxylanase activity levels. Analysis of the levels of reducing end xylose (RX) and solubilized AX (S-AX) formed during mixing and resting and their correlation with the endoxylanase activity in the flour milling fractions showed that solubilization of AX during the mixing phase is mainly due to mechanical forces, while solubilization of AX during resting is caused by endoxylanase activity. Moreover, solubilization of AX during the dough resting phase is more outspoken than that during the mixing phase. Besides endoxylanase activity, there were significant xylosidase and arabinofuranosidase activities during the dough resting phase. The results indicate that wheat flour-associated endoxylanases can alter part of the AX in dough, thereby changing their functionality in bread making and potentially affecting dough and end product properties. PMID:17661495

  11. Application of model bread baking in the examination of arabinoxylan-protein complexes in rye bread.

    Science.gov (United States)

    Buksa, Krzysztof

    2016-09-01

    The changes in molecular mass of arabinoxylan (AX) and protein caused by bread baking process were examined using a model rye bread. Instead of the normal flour, the dough contained starch, water-extractable AX and protein which were isolated from rye wholemeal. From the crumb of selected model breads, starch was removed releasing AX-protein complexes, which were further examined by size exclusion chromatography. On the basis of the research, it was concluded that optimum model mix can be composed of 3-6% AX and 3-6% rye protein isolate at 94-88% of rye starch meaning with the most similar properties to low extraction rye flour. Application of model rye bread allowed to examine the interactions between AX and proteins. Bread baked with a share of AX, rye protein and starch, from which the complexes of the highest molar mass were isolated, was characterized by the strongest structure of the bread crumb.

  12. Tracking the connection between evolutionary and functional shifts using the fungal lipase/feruloyl esterase A family

    Directory of Open Access Journals (Sweden)

    Asther Marcel

    2006-11-01

    Full Text Available Abstract Background There have been many claims of adaptive molecular evolution, but what role does positive selection play in functional divergence? The aim of this study was to test the relationship between evolutionary and functional shifts with special emphasis on the role of the environment. For this purpose, we studied the fungal lipase/feruloyl esterase A family, whose functional diversification makes it a very promising candidate. Results The results suggested functional shift following a duplication event where neofunctionalisation of feruloyl esterase A had occurred with conservation of the ancestral lipase function. Evolutionary shift was detected using the branch-site model for testing positive selection on individual codons along specific lineages. Positively selected amino acids were detected. Furthermore, biological data obtained from site-directed mutagenesis experiments clearly demonstrated that certain amino acids under positive selection were involved in the functional shift. We reassessed evolutionary history in terms of environmental response, and hypothesized that environmental changes such as colonisation by terrestrial plants might have driven adaptation by functional diversification in Euascomycetes (Aspergilli, thus conferring a selective advantage on this group. Conclusion The results reported here illustrate a rare example of connection between fundamental events in molecular evolution. We demonstrated an unequivocal connection between evolutionary and functional shifts, which led us to conclude that these events were probably linked to environmental change.

  13. Dependency of the hydrogen bonding capacity of the solvent anion on the thermal stability of feruloyl esterases in ionic liquid systems

    DEFF Research Database (Denmark)

    Zeuner, Birgitte; Ståhlberg, Tim; Nguyen van Buu, Olivier;

    2011-01-01

    Three feruloyl esterases, EC 3.1.1.73, (FAEs), namely FAE A from Aspergillus niger (AnFaeA), FAE C from Aspergillus nidulans (AndFaeC), and the FAE activity in a commercial b-glucanase mixture from Humicola insolens (Ultraflo L) were tested for their ability to catalyse esterification of sinapic ...

  14. Characterization of water and alkali extractable arabinoxylan from wheat and rye under standardized conditions.

    Science.gov (United States)

    Buksa, Krzysztof; Praznik, Werner; Loeppert, Renate; Nowotna, Anna

    2016-03-01

    Arabinoxylans (AXs) are an important component of wheat and rye dough. They bind water, contribute to the formation of viscous dough and improve the quality of bread. For the application of AX fractions in bread making process, it is useful to record a quality profile of wheat fractions compared to the quality profile of rye fractions under standardized conditions. In this work water and alkali extractable AX containing fractions, from wheat- and rye wholemeal, were extracted under standardized conditions and characterized. For analysis of composition, structural features, and molecular dimension a combination of chemical, physicochemical, enzymatic and chromatographic techniques was applied. The molar mass distributions obtained by means of an innovative colorimetric pentose detection in the eluted SEC fractions were comparable for all under standardized conditions extracted AXs. The determined molar masses of AXs extracted both from wheat- and from rye grain were close to 2.0 × 10(5) g/mol for water extractable AXs and 3.0 × 10(5) g/mol for alkali extractable AXs. Different susceptibility to endoxylanase treatment, having been observed as differences in the SEC profiles, may be evidence of structural differences between AXs depending on their origin. The viscosities of AX solutions were strongly influenced by their molar mass and structure; samples being less susceptible to endoxylanase provided solutions of higher viscosity. PMID:27570263

  15. Purification and characterisation of arabinoxylan arabinofuranohydrolase I responsible for the filterability of barley malt.

    Science.gov (United States)

    Li, Xiaomin; Gao, Fei; Cai, Guolin; Jin, Zhao; Lu, Jian; Dong, Jianjun; Yin, Hua; Yu, Junhong; Yang, Mei

    2015-05-01

    Dan'er is a widely grown malt barley cultivar in China, but its filterability defects have severely impeded its application in beer brewing. Previous investigations have suggested that we should identify the malt filterability correlated proteins, one of which was postulated to be arabinoxylan arabinofuranohydrolase I (AXAH-I). To verify this hypothesis, we purified AXAH-I from Dan'er malt, characterised its enzyme performance, and investigated its influence on filterability by adding different amounts of purified enzyme to the mash. With 6 mU g(-1) malt AXAH-I supplemented, the wort separation rate increased by 31.8%, viscosity decreased by 3.6%, and the endosperm reserve contents declined concomitantly. Unexpectedly, the wort turbidity increased with increasing AXAH-I. We also tried to optimise the use of currently available commercial enzyme products for filterability improvement in beer brewing, by supplementing them with purified AXAH-I and β-amylase. AXAH-I could be a functional component for novel commercial enzyme products in the beer industry.

  16. Different human gut models reveal the distinct fermentation patterns of Arabinoxylan versus inulin.

    Science.gov (United States)

    Van den Abbeele, Pieter; Venema, Koen; Van de Wiele, Tom; Verstraete, Willy; Possemiers, Sam

    2013-10-16

    Different in vitro models have been developed to assess how food compounds affect the human gut microbiota. Using two such models (SHIME(R) and TIM-2), we compared how long-chain arabinoxylan (LC-AX), a wheat-derived potentially prebiotic fiber, and inulin (IN), a well-established prebiotic compound, modulate SCFA production and bifidobacteria composition. While both the SHIME and TIM-2 differ in experimental design, they both demonstrated that LC-AX and IN specifically increased the health-promoting metabolites propionate and butyrate, respectively. Furthermore, LC-AX stimulated Bifidobacterium longum, while IN stimulated other bifidobacteria including Bifidobacterium adolescentis. The SHIME experiment also revealed that effects of LC-AX were more persistent during the 2-week wash-out period. These results confirm a recent in vivo study, during which humanized rats were treated with the same LC-AX/IN. In conclusion, results from different human gut models suggest that, besides IN, LC-AX are promising prebiotic candidates with high specificity toward Bifidobacterium longum and a selective propionate increase.

  17. Purification and characterisation of arabinoxylan arabinofuranohydrolase I responsible for the filterability of barley malt.

    Science.gov (United States)

    Li, Xiaomin; Gao, Fei; Cai, Guolin; Jin, Zhao; Lu, Jian; Dong, Jianjun; Yin, Hua; Yu, Junhong; Yang, Mei

    2015-05-01

    Dan'er is a widely grown malt barley cultivar in China, but its filterability defects have severely impeded its application in beer brewing. Previous investigations have suggested that we should identify the malt filterability correlated proteins, one of which was postulated to be arabinoxylan arabinofuranohydrolase I (AXAH-I). To verify this hypothesis, we purified AXAH-I from Dan'er malt, characterised its enzyme performance, and investigated its influence on filterability by adding different amounts of purified enzyme to the mash. With 6 mU g(-1) malt AXAH-I supplemented, the wort separation rate increased by 31.8%, viscosity decreased by 3.6%, and the endosperm reserve contents declined concomitantly. Unexpectedly, the wort turbidity increased with increasing AXAH-I. We also tried to optimise the use of currently available commercial enzyme products for filterability improvement in beer brewing, by supplementing them with purified AXAH-I and β-amylase. AXAH-I could be a functional component for novel commercial enzyme products in the beer industry. PMID:25529682

  18. Evaluation of the prebiotic potential of arabinoxylans from brewer's spent grain.

    Science.gov (United States)

    Reis, Sofia F; Gullón, Beatriz; Gullón, Patricia; Ferreira, Susana; Maia, Cláudio J; Alonso, José L; Domingues, Fernanda C; Abu-Ghannam, Nissreen

    2014-11-01

    Arabinoxylans (AX) consumption has been related to the treatment and prevention of cardiovascular diseases, type II diabetes, colorectal cancer and obesity. The beneficial health effects are conferred through gut microbiota modulation, and therefore, they have been proposed as potential slowly fermentable prebiotic candidates. As the mechanisms are not yet well understood, the prebiotic potential of AX from brewer's spent grain (BSG) has been investigated. Two types of AX from BSG (AX1 and AX2) of different length and branching averages were fermented with human faecal inocula and compared to fermented cultures containing a commercial prebiotic (fructooligosaccharide (FOS)) and cultures with no added carbohydrate (control). Results demonstrated that the AX were extensively metabolised after 48 h of fermentation. The pH decreased along fermentation and the lowest value was achieved in AX1 cultures. The production of short chain fatty acids (SCFA) was higher in AX cultures than in cultures containing FOS and controls, with AX1 presenting the highest concentrations. The stimulatory effect of beneficial bacteria was higher in AX cultures, and AX2 presented the highest positive effect. Prebiotic potential of AX from BSG was confirmed by the production of SCFA and the modulation of gut microbiota, especially by the high increase in bifidobacteria populations. PMID:25117549

  19. Characterization of water and alkali extractable arabinoxylan from wheat and rye under standardized conditions.

    Science.gov (United States)

    Buksa, Krzysztof; Praznik, Werner; Loeppert, Renate; Nowotna, Anna

    2016-03-01

    Arabinoxylans (AXs) are an important component of wheat and rye dough. They bind water, contribute to the formation of viscous dough and improve the quality of bread. For the application of AX fractions in bread making process, it is useful to record a quality profile of wheat fractions compared to the quality profile of rye fractions under standardized conditions. In this work water and alkali extractable AX containing fractions, from wheat- and rye wholemeal, were extracted under standardized conditions and characterized. For analysis of composition, structural features, and molecular dimension a combination of chemical, physicochemical, enzymatic and chromatographic techniques was applied. The molar mass distributions obtained by means of an innovative colorimetric pentose detection in the eluted SEC fractions were comparable for all under standardized conditions extracted AXs. The determined molar masses of AXs extracted both from wheat- and from rye grain were close to 2.0 × 10(5) g/mol for water extractable AXs and 3.0 × 10(5) g/mol for alkali extractable AXs. Different susceptibility to endoxylanase treatment, having been observed as differences in the SEC profiles, may be evidence of structural differences between AXs depending on their origin. The viscosities of AX solutions were strongly influenced by their molar mass and structure; samples being less susceptible to endoxylanase provided solutions of higher viscosity.

  20. Concentrated Arabinoxylan but Not Concentrated Beta-Glucan in Wheat Bread Has Similar Effects on Postprandial Insulin as Whole-Grain Rye in Porto-arterial Catheterized Pigs

    DEFF Research Database (Denmark)

    Christensen, Kirstine Lykke; Hedemann, Mette Skou; Lærke, Helle Nygaard;

    2013-01-01

    The acute glycemic effects of concentrated dietary fibers (DF) versus whole-grain rye were studied in portoarterial catheterized pigs. Two white wheat breads with wheat arabinoxylan (AX) or oat beta-glucan (BG), two rye breads with intact rye kernels (RK) or milled rye (GR), and a low DF white...... min postprandial for AX and GR (74.4 and 129 pmol/min for AX and GR, respectively, compared to 738 pmol/min for WF, P effective in improving insulin economy, suggesting that arabinoxylan from wheat and rye induces similar outcomes in the metabolic...

  1. Feruloyl esterases as a tool for the release of phenolic compounds from agro-industrial by-products.

    Science.gov (United States)

    Benoit, Isabelle; Navarro, David; Marnet, Nathalie; Rakotomanomana, Nnjara; Lesage-Meessen, Laurence; Sigoillot, Jean-Claude; Asther, Marcel; Asther, Michèle

    2006-08-14

    Agro-industrial by-products are a potential source of added-value phenolic acids with promising applications in the food and pharmaceutical industries. Here two purified feruloyl esterases from Aspergillus niger, FAEA and FAEB were tested for their ability to release phenolic acids such as caffeic acid, p-coumaric acid and ferulic acid from coffee pulp, apple marc and wheat straw. Their hydrolysis activity was evaluated and compared with their action on maize bran and sugar beet pulp. The specificity of both enzymes against natural and synthetic substrates was evaluated; particular attention was paid to quinic esters and lignin monomers. The efficiency of both enzymes on model substrates was studied. We show the ability of these enzymes to hydrolyze quinic esters and ester linkages between phenolic acids and lignin monomer.

  2. [Structure and functions of glutathione transferases].

    Science.gov (United States)

    Fedets, O M

    2014-01-01

    Data about classification, nomenclature, structure, substrate specificity and role of many glutathione transferase's isoenzymes in cell functions have been summarised. The enzyme has been discovered more than 50 years ago. This family of proteins is updated continuously. It has very different composition and will have demand for system analysis for many years.

  3. Ball milling improves extractability and affects molecular properties of psyllium (Plantago ovata Forsk) seed husk arabinoxylan.

    Science.gov (United States)

    Van Craeyveld, Valerie; Delcour, Jan A; Courtin, Christophe M

    2008-12-10

    Psyllium (Plantago ovata Forsk) seed husk (PSH) is very rich in arabinoxylan (AX). However, its high gelling capacity and the complex nature of the AX make it difficult to process. In this study, ball milling was investigated as a tool for enhancing PSH AX water extractability and molecular mass (MM). A 48 h laboratory-scale ball mill treatment under standardized optimal conditions reduced the PSH average particle size from 161 microm for the untreated sample to 6 microm. Concurrently, it increased the water-extractable AX (WE-AX) level from 13 (untreated PSH) to 90% of the total PSH AX. While the WE-AX of the untreated PSH had a peak MM of 216 kDa and an arabinose to xylose (A/X) ratio of 0.20, WE-AX fragments from ball mill-pretreated PSH had a peak MM of 22 kDa and an A/X ratio of 0.31. Ball milling further drastically reduced the intrinsic viscosity of PSH extracts and their water-holding capacity. Prolonged treatment brought almost all AX (98%) in solution and yielded WE-AX fragments with an even higher A/X ratio (0.42) and a lower peak MM (11 kDa). While impact and jet milling of PSH equally led to significant reductions in particle size, these technologies only marginally affected the water extractability of PSH AX. This implies that ball milling affects PSH particles and their constituent molecules differently than impact and jet milling. PMID:19007123

  4. Mode of endosperm and wholemeal arabinoxylans solubilisation during rye breadmaking: genotypic diversity in the level, substitution degree and macromolecular characteristics.

    Science.gov (United States)

    Cyran, Malgorzata R; Dynkowska, Wioletta M

    2014-02-15

    Insight into solubilisation mechanisms of rye arabinoxylans during breadmaking is important for understanding the biochemical processes that affect bread attributes. Purified ethanol precipitated water-extractable arabinoxylans (WE-AX) and residual unextractable counterparts (WU-AX) were isolated from rye flours and resulting breads. While the endosperm flours had lower endoxylanase activities and higher arabinose-to-xylose ratios of WU-AX than those of corresponding wholemeals, there were not any significant differences between them in the mean amounts of WU-AX hydrolysed during breadmaking. Nevertheless, they were highly affected by rye cultivar used for breadmaking. On average, 42% and 36% of WU-AX were recovered in bread WE-AX fraction, causing its 11% and 8% increase, respectively for endosperm and wholemeal breads. Bread WE-AX, however, had lower molecular weights than those of starting flours, implying chains depolymerisation. Degree of AX solubilisation depends mainly on rye genotype used, determining combined effect of enzymatic and acid hydrolyses, associations and fine structure of AX.

  5. Edible arabinoxylan-based films. 1. Effects of lipid type on water vapor permeability, film structure, and other physical characteristics.

    Science.gov (United States)

    Péroval, Claudine; Debeaufort, Frédéric; Despré, Denis; Voilley, Andrée

    2002-07-01

    Arabinoxylans (AX) are natural fibers extracted from maize bran, an industrial byproduct. To promote this polymer as a food ingredient, development of edible coatings and films had been proposed. Indeed, composite arabinoxylan-based films were prepared by emulsifying a fat: palmitic acid, oleic acid, triolein, or a hydrogenated palm oil (OK35). Lipid effects on water vapor permeability (WVP), surface hydrophobicity (contact angles), lipid particle size, and mechanical properties were investigated. Results showed that OK35-AX emulsion films had the lowest WVP. Emulsified films presented a bimodal particle size distribution; however, the smallest particle mean diameter (0.54 microm) was observed in OK35-AX emulsion films. Contact angles of water comparable to those observed for LDPE films (>90 degrees ) are measured on the OK35-AX film surface. Finally, only triolein-AX emulsion films had elongation higher than films without lipid. These results suggest that OK35 enhances functional properties of AX-based films and should be retained for further research.

  6. Effects of Resistant Starch and Arabinoxylan on Parameters Related to Large Intestinal and Metabolic Health in Pigs Fed Fat-Rich Diets

    DEFF Research Database (Denmark)

    Nielsen, Tina Skau; Theil, Peter Kappel; Purup, Stig;

    2015-01-01

    This study compared the effects of a resistant starch (RS)-rich, arabinoxylan (AX)-rich, or low-DF Western-style control diet (all high-fat) on large intestinal gene expression, adiposity, and glycemic response parameters in pigs. Animals were slaughtered after 3 weeks of treatment. Plasma butyra...

  7. Molecular weight changes of arabinoxylans of wheat and rye incurred by the digestion processes in the upper gastrointestinal tract of pigs

    DEFF Research Database (Denmark)

    Legall, Maud; Eybye, Karin; Knudsen, Knud Erik Bach

    2010-01-01

    Twenty cannulated-pigs were fed wheat flour (WFL), wheat whole grain (WWG), wheat aleurone flour (WAF) and rye aleurone flour (RAF) differing by their arabinoxylans (AX) proportions. After ileal collection of digesta (0800–1800), the soluble phase was extracted. The weight average molecular weight...

  8. Purification and characterization of the Oligosaccharyl transferase

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, T.M.

    1990-11-01

    Oligosaccharyl transferase was characterized to be a glycoprotein with at least one saccharide unit that had a D-manno or D- glucopyranose configuration with unmodified hydroxy groups at C-3, C-4 and C-6, using a Concanavalin A affinity column. This afforded a 100 fold increase in the transferase purity in the solubilized microsomal sample and also removed over 90% of the microsomal proteins (the cytosolic ones being removed before solubilization). The detergent, N,N-Dimethyldodecylamine N-oxide (LDAO) was used for solubilization and it yielded a system compatible with the assay and the purification steps. An efficient method for detergent extraction without dilution of sample or protein precipitation was also developed.

  9. Glutathione Transferase (GST)-Activated Prodrugs

    OpenAIRE

    Andrea Calderan; Paolo Ruzza

    2013-01-01

    Glutathione transferase (formerly GST) catalyzes the inactivation of various electrophile-producing anticancer agents via conjugation to the tripeptide glutathione. Moreover, several data link the overexpression of some GSTs, in particular GSTP1-1, to both natural and acquired resistance to various structurally unrelated anticancer drugs. Tumor overexpression of these proteins has provided a rationale for the search of GST inhibitors and GST activated cytotoxic prodrugs. In the present review...

  10. SIKLODEKSTRIN GLIKOSIL TRANSFERASE DAN PEMANFAATANNYA DALAM INDUSTRI [Cyclodextrin Glycosyl Transferase and its application in industries

    Directory of Open Access Journals (Sweden)

    Budiasih Wahyuntari

    2005-12-01

    Full Text Available Cyclodextrin glycosyl transferase (CGT-ase is mainly produced by Bacilli. Systematical name of the enzyme is E.C. 2.4.1.19 a-1,4 glucan-4-glycosyl transferase. The enzyme catalyzes hydrolysis of starch intramolecular, and intermolecular transglycosylation of a-1,4, glucan chains. Cyclodextrins are a-1,4 linked cyclic oligosaccharides resulting from enzymatic degradation of starch by cyclodextrin glycosyl transferase through untramolecular transglycosylation. The major cyclodextrins are made up of 6, 7 and 8 glucopyranose units which are known as a-, b-, and y-cyclodextrin. All CGT-ase catalyze three kinds of cyclodextrins, the proportion of the cyclodextrins depends on the enzyme source and reaction conditions. The intermolecular transglycosylation ability of the enzyme has been applied in transfering glycosyl residues into suitable acceptor. Transglycosylation by the enzymes have been tested to improve solubility of some flavonoids and to favor precipitation ci some glycosides.

  11. Ferulic acid release and 4-vinylguaiacol formation during brewing and fermentation: indications for feruloyl esterase activity in Saccharomyces cerevisiae.

    Science.gov (United States)

    Coghe, Stefan; Benoot, Koen; Delvaux, Filip; Vanderhaegen, Bart; Delvaux, Freddy R

    2004-02-11

    The release of ferulic acid and the subsequent thermal or enzymatic decarboxylation to 4-vinylguaiacol are inherent to the beer production process. Phenolic, medicinal, or clove-like flavors originating from 4-vinylguaiacol frequently occur in beer made with wheat or wheat malt. To evaluate the release of ferulic acid and the transformation to 4-vinylguaiacol, beer was brewed with different proportions of barley malt, wheat, and wheat malt. Ferulic acid as well as 4-vinylguaiacol levels were determined by HPLC at several stages of the beer production process. During brewing, ferulic acid was released at the initial mashing phase, whereas moderate levels of 4-vinylguaiacol were formed by wort boiling. Higher levels of the phenolic flavor compound were produced during fermentations with brewery yeast strains of the Pof(+) phenotype. In beer made with barley malt, ferulic acid was mainly released during the brewing process. Conversely, 60-90% of ferulic acid in wheat or wheat malt beer was hydrolyzed during fermentation, causing higher 4-vinylguaiacol levels in these beers. As cereal enzymes are most likely inactivated during wort boiling, the additional release of ferulic acid during fermentation suggests the activity of feruloyl esterases produced by brewer's yeast. PMID:14759156

  12. Hypoglycemic and Hypotensive Activity of a Root Extract of Smilax aristolochiifolia, Standardized on N-trans-Feruloyl-Tyramine

    Directory of Open Access Journals (Sweden)

    Carol Arely Botello Amaro

    2014-07-01

    Full Text Available The metabolic syndrome (MS is a condition consisting of various metabolic abnormalities that are risk factors for developing kidney failure, cardiovascular, vascular and cerebrovascular diseases, among others. The prevalence of this syndrome shows a marked increase. The aim of this study was to investigate the pharmacological effect of Smilax aristolochiifolia root on some components of MS and obtain some of the active principle using chromatographic techniques. The compound isolated was N-trans-feruloyl tyramine NTF (1, and its structure was determined by spectroscopic and spectrometric analyses. The whole extract and the standardized fractions were able to control the weight gain around 30%; the fraction rich in NTF was able to decrease the hypertriglyceridemia by 60%. The insulin resistance decreased by approximately 40%; the same happened with blood pressure, since the values of systolic and diastolic pressure fell on average 31% and 37% respectively, to levels comparable to normal value. The treatment also had an immunomodulatory effect on the low-grade inflammation associated with obesity, since it significantly decreased the relative production of pro-inflammatory cytokines regarding anti-inflammatory cytokines, both kidney and adipose tissue. Therefore it can be concluded that the extract and fractions of Smilax aristolochiifolia root with NTF are useful to counteract some symptoms of MS in animal models.

  13. Characterization of arabinoxylan/cellulose nanocrystals gels to investigate fluorescent probes mobility in bioinspired models of plant secondary cell wall.

    Science.gov (United States)

    Paës, Gabriel; Chabbert, Brigitte

    2012-01-01

    Biomass from lignocellulose (LC) is a highly complex network of cellulose, hemicellulose, and lignin, which is considered to be a sustainable source of fuels, chemicals and materials. To achieve an environmental friendly and efficient LC upgrading, a better understanding of the LC architecture is necessary. We have devised some LC bioinspired model systems, based on arabinoxylan gels, in which mobility of dextrans and BSA grafted with FITC has been studied by FRAP. Our results indicate that the probes diffusion is more influenced by their hydrodynamic radius than by the gel mesh size. The addition of some cellulose nanocrystals (CNCs) decreases polymer chain mobility and has low effect on the probes diffusion, suggesting that the gels are better organized in the presence of CNCs, as shown by rheological measurements and scanning electronic microscopy observations. This demonstrates that the FRAP analysis can be a powerful tool to screen the architecture of LC model systems.

  14. An efficient arabinoxylan-debranching α-l-arabinofuranosidase of family GH62 from Aspergillus nidulans contains a secondary carbohydrate binding site

    DEFF Research Database (Denmark)

    Wilkens, Casper; Andersen, Susan; Petersen, Bent O.;

    2016-01-01

    An α-l-arabinofuranosidase of GH62 from Aspergillus nidulans FGSC A4 (AnAbf62A-m2,3) has an unusually high activity towards wheat arabinoxylan (WAX) (67 U/mg; kcat = 178/s, Km = 4.90 mg/ml) and arabinoxylooligosaccharides (AXOS) with degrees of polymerisation (DP) 3–5 (37–80 U/mg), but about 50 t...

  15. Production and functional characterisation of arabinoxylan-oligosaccharides from wheat (Triticum aestivum L.) bran and psyllium (Plantago ovata Forsk) seed husk

    OpenAIRE

    Van Craeyveld, Valerie

    2009-01-01

    Prebiotica zijn voedingscomponenten die niet geabsorbeerd of gehydrolyse erd kunnen worden door enzymen van het gastrointestinaal stelsel, maar d ie in de dikke darm selectief gefermenteerd worden door bepaalde types b acteriën die een gezondheids-bevorderend effect uitoefenen op hun gasthe er. Naast inuline en fructo-oligosachariden, de meest bestudeerde prebio tica, vormen arabinoxylan-oligosachariden (AXOS) mogelijk een nieuwe kla sse van prebiotische componenten. AXOS kunnen uit tarwezeme...

  16. Inter-conversion of catalytic abilities in a bifunctional carboxyl/feruloyl-esterase from earthworm gut metagenome.

    Science.gov (United States)

    Vieites, José María; Ghazi, Azam; Beloqui, Ana; Polaina, Julio; Andreu, José M; Golyshina, Olga V; Nechitaylo, Taras Y; Waliczek, Agnes; Yakimov, Michail M; Golyshin, Peter N; Ferrer, Manuel

    2010-01-01

    Carboxyl esterases (CE) exhibit various reaction specificities despite of their overall structural similarity. In present study we have exploited functional metagenomics, saturation mutagenesis and experimental protein evolution to explore residues that have a significant role in substrate discrimination. We used an enzyme, designated 3A6, derived from the earthworm gut metagenome that exhibits CE and feruloyl esterase (FAE) activities with p-nitrophenyl and cinnamate esters, respectively, with a [(k(cat)/K(m))](CE)/[(k(cat)/K(m))](FAE) factor of 17. Modelling-guided saturation mutagenesis at specific hotspots (Lys(281), Asp(282), Asn(316) and Lys(317)) situated close to the catalytic core (Ser(143)/Asp(273)/His(305)) and a deletion of a 34-AA-long peptide fragment yielded mutants with the highest CE activity, while cinnamate ester bond hydrolysis was effectively abolished. Although, single to triple mutants with both improved activities (up to 180-fold in k(cat)/K(m) values) and enzymes with inverted specificity ((k(cat)/K(m))(CE)/(k(cat)/K(m))(FAE) ratio of ∼0.4) were identified, no CE inactive variant was found. Screening of a large error-prone PCR-generated library yielded by far less mutants for substrate discrimination. We also found that no significant changes in CE activation energy occurs after any mutation (7.3 to -5.6 J mol(-1)), whereas a direct correlation between loss/gain of FAE function and activation energies (from 33.05 to -13.7 J mol(-1)) was found. Results suggest that the FAE activity in 3A6 may have evolved via introduction of a limited number of 'hot spot' mutations in a common CE ancestor, which may retain the original hydrolytic activity due to lower restrictive energy barriers but conveys a dynamic energetically favourable switch of a second hydrolytic reaction. PMID:21255305

  17. Glutathione S-transferases as risk factors in prostate cancer

    DEFF Research Database (Denmark)

    Autrup, Judith; Thomassen, L.H.; Olsen, J.H.;

    1999-01-01

    Glutathione S-transferases are enzymes involved in the metabolism of carcinogens and in the defence against reactive oxygen species. Genetic polymorphisms have been detected in glutathione S-transferases M1, T1 and P1, and some of these polymorphisms have been associated with an increased risk...

  18. Nomenclature for mammalian soluble glutathione transferases.

    Science.gov (United States)

    Mannervik, Bengt; Board, Philip G; Hayes, John D; Listowsky, Irving; Pearson, William R

    2005-01-01

    The nomenclature for human soluble glutathione transferases (GSTs) is extended to include new members of the GST superfamily that have been discovered, sequenced, and shown to be expressed. The GST nomenclature is based on primary structure similarities and the division of GSTs into classes of more closely related sequences. The classes are designated by the names of the Greek letters: Alpha, Mu, Pi, etc., abbreviated in Roman capitals: A, M, P, and so on. (The Greek characters should not be used.) Class members are distinguished by Arabic numerals and the native dimeric protein structures are named according to their subunit composition (e.g., GST A1-2 is the enzyme composed of subunits 1 and 2 in the Alpha class). Soluble GSTs from other mammalian species can be classified in the same manner as the human enzymes, and this chapter presents the application of the nomenclature to the rat and mouse GSTs. PMID:16399376

  19. Biochemical genetics of glutathione-S-transferase in man.

    OpenAIRE

    Board, P G

    1981-01-01

    Glutathione-S-transferases from liver and erythrocytes have been separated by starch gel electrophoresis and localized by a specific staining procedure. The data suggest that the most active glutathione-S-transferases in liver are the products of two autosomal loci, GST1 and GST2. Both these loci are polymorphic, and there is evidence that a common null allele exists at the GST1 locus. The glutathione-S-transferase expressed in erythrocytes is the product of a third locus, GST3, and is not po...

  20. Antioxidant capacity of arabinoxylan oligosaccharide fractions prepared from wheat aleurone using Trichoderma viride or Neocallimastix patriciarum xylanase.

    Science.gov (United States)

    Malunga, Lovemore Nkhata; Beta, Trust

    2015-01-15

    The effect of xylanase type (Trichoderma viride or Neocallimastix patriciarum) and graded ethanol fractionation on the antioxidant capacity (AOC) of arabinoxylan oligosaccharides (AXOS) obtained from wheat aleurone was investigated. AXOS yields were higher using N. patriciarum (62%) than T. viride (44%). The fraction (F100) collected at >80% ethanol concentration constituted 60% of total recovered AXOS. Degree of substitution ranged from 0.20 to 0.60 for ethanol graded fractions. Ferulic acid (FA) esterified to AXOS (8.0 μg/ mg) was 2-fold lower for the N. patriciarum treatment. The mean AOC (41.6, 183.1, and 394.9 μM TE/mg) of T. viride treated AXOS was >1.4-fold higher than N. patriciarum treatment using DPPH and ABTS and ORAC assays, respectively. Fraction F100 had highest AOC. AOC was influenced by the content of esterified FA (R(2)=0.94). The type of xylanase had a major influence on the AOC of the resultant AXOS rich in FA content.

  1. The Genetic Architecture of Murine Glutathione Transferases.

    Directory of Open Access Journals (Sweden)

    Lu Lu

    Full Text Available Glutathione S-transferase (GST genes play a protective role against oxidative stress and may influence disease risk and drug pharmacokinetics. In this study, massive multiscalar trait profiling across a large population of mice derived from a cross between C57BL/6J (B6 and DBA2/J (D2--the BXD family--was combined with linkage and bioinformatic analyses to characterize mechanisms controlling GST expression and to identify downstream consequences of this variation. Similar to humans, mice show a wide range in expression of GST family members. Variation in the expression of Gsta4, Gstt2, Gstz1, Gsto1, and Mgst3 is modulated by local expression QTLs (eQTLs in several tissues. Higher expression of Gsto1 in brain and liver of BXD strains is strongly associated (P < 0.01 with inheritance of the B6 parental allele whereas higher expression of Gsta4 and Mgst3 in brain and liver, and Gstt2 and Gstz1 in brain is strongly associated with inheritance of the D2 parental allele. Allele-specific assays confirmed that expression of Gsto1, Gsta4, and Mgst3 are modulated by sequence variants within or near each gene locus. We exploited this endogenous variation to identify coexpression networks and downstream targets in mouse and human. Through a combined systems genetics approach, we provide new insight into the biological role of naturally occurring variants in GST genes.

  2. Glutathione transferases in the bioactivation of azathioprine.

    Science.gov (United States)

    Modén, Olof; Mannervik, Bengt

    2014-01-01

    The prodrug azathioprine is primarily used for maintaining remission in inflammatory bowel disease, but approximately 30% of the patients suffer adverse side effects. The prodrug is activated by glutathione conjugation and release of 6-mercaptopurine, a reaction most efficiently catalyzed by glutathione transferase (GST) A2-2. Among five genotypes of GST A2-2, the variant A2*E has threefold-fourfold higher catalytic efficiency with azathioprine, suggesting that the expression of A2*E could boost 6-mercaptopurine release and adverse side effects in treated patients. Structure-activity studies of the GST A2-2 variants and homologous alpha class GSTs were made to delineate the determinants of high catalytic efficiency compared to other alpha class GSTs. Engineered chimeras identified GST peptide segments of importance, and replacing the corresponding regions in low-activity GSTs by these short segments produced chimeras with higher azathioprine activity. By contrast, H-site mutagenesis led to decreased azathioprine activity when active-site positions 208 and 213 in these favored segments were mutagenized. Alternative substitutions indicated that hydrophobic residues were favored. A pertinent question is whether variant A2*E represents the highest azathioprine activity achievable within the GST structural framework. This issue was addressed by mutagenesis of H-site residues assumed to interact with the substrate based on molecular modeling. The mutants with notably enhanced activities had small or polar residues in the mutated positions. The most active mutant L107G/L108D/F222H displayed a 70-fold enhanced catalytic efficiency with azathioprine. The determination of its structure by X-ray crystallography showed an expanded H-site, suggesting improved accommodation of the transition state for catalysis.

  3. Arabinoxylans and inulin differentially modulate the mucosal and luminal gut microbiota and mucin-degradation in humanized rats.

    Science.gov (United States)

    Van den Abbeele, Pieter; Gérard, Philippe; Rabot, Sylvie; Bruneau, Aurélia; El Aidy, Sahar; Derrien, Muriel; Kleerebezem, Michiel; Zoetendal, Erwin G; Smidt, Hauke; Verstraete, Willy; Van de Wiele, Tom; Possemiers, Sam

    2011-10-01

    The endogenous gut microbiota affects the host in many ways. Prebiotics should favour beneficial intestinal microbes and thus improve host health. In this study, we investigated how a novel class of potential prebiotic long-chain arabinoxylans (LC-AX) and the well-established prebiotic inulin (IN) modulate the gut microbiota of humanized rats. Six weeks after axenic rats were inoculated with a human faecal microbiota, their colonic microbiota was similar to this inoculum (∼ 70%), whereas their caecal microbiota was enriched with Verrucomicrobia and Firmicutes concomitant with lower abundance of Bacteroidetes. Moreover, different Bifidobacterium species colonized the lumen (B. adolescentis) and mucus (B. longum and B. bifidum). Both LC-AX and IN increased SCFA levels and induced a shift from acetate towards health-promoting propionate and butyrate respectively. By applying a high-resolution phylogenetic micro-array (HITChip) at the site of fermentation (caecum), IN and LC-AX were shown to stimulate bacterial groups with known butyrate-producers (Roseburia intestinalis, Eubacterium rectale, Anaerostipes caccae) and bifidobacteria (B. longum) respectively. Prebiotic administration also resulted in lower caecal abundances of the mucin-degrading Akkermansia muciniphila and potentially more mucin production by the host. Both factors might explain the increased caecal mucin levels for LC-AX (threefold) and IN (sixfold). These mucins were degraded along the colon, resulting in high faecal abundances of Akkermansia muciniphila for LC-AX and especially IN-treated rats. Finally, the microbial changes caused an adaptation period for the host with less weight gain, after which the host fine-tuned the interaction with this altered microbiota. Our results demonstrate that next to IN, LC-AX are promising prebiotic compounds by stimulating production of health-promoting metabolites by specific microbes in the proximal regions. Further, prebiotic supplementation shifted mucin

  4. Glutathione S-Transferase Isoenzymes from Streptomyces griseus

    OpenAIRE

    Dhar, Kajari; Dhar, Alok; Rosazza, John P. N.

    2003-01-01

    An inducible, cytosolic glutathione S-transferase (GST) was purified from Streptomyces griseus. GST isoenzymes with pI values of 6.8 and 7.9 used standard GST substrates including 1-chloro-2,4-dinitrobenzene. GST had subunit and native Mrs of 24 and 48, respectively, and the N-terminal sequence SMILXYWDIIRGLPAH.

  5. METAL-INDUCED INHIBITION OF GLUTATHIONE S-TRANSFERASES

    Science.gov (United States)

    The glutathione S-transferases comprise a group of multi-functional enzymes involved in the biotransformation/detoxication of a broad spectrum of hydrophobic compounds bearing an electrophilic center. The enzymes facilitate the nucleophilic attack of the -SH group of reduced glut...

  6. Rational design of an organometallic glutathione transferase inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Ang, W.H.; Parker, L.J.; De Luca, A.; Juillerat-Jeanneret, L.; Morton, C.J.; LoBello, M.; Parker, M.W.; Dyson, P.J.; (ISIC)

    2010-08-17

    A hybrid organic-inorganic (organometallic) inhibitor was designed to target glutathione transferases. The metal center is used to direct protein binding, while the organic moiety acts as the active-site inhibitor. The mechanism of inhibition was studied using a range of biophysical and biochemical methods.

  7. Interaction of pleuromutilin derivatives with the ribosomal peptidyl transferase center

    DEFF Research Database (Denmark)

    Long, K. S.; Hansen, L. K.; Jakobsen, L.;

    2006-01-01

    Tiamulin is a pleuromutilin antibiotic that is used in veterinary medicine. The recently published crystal structure of a tiamulin-50S ribosomal subunit complex provides detailed information about how this drug targets the peptidyl transferase center of the ribosome. To promote rational design...

  8. Homogentisate solanesyl transferase (HST) cDNA’s in maize

    Science.gov (United States)

    Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This reaction ...

  9. Diets high in resistent starch and arabinoxylan modulate digestion processes and SCFA pool size in the large intestine and faecal microbial composition in pigs

    DEFF Research Database (Denmark)

    Nielsen, Tina Skau; Lærke, Helle Nygaard; Theil, Peter Kappel;

    2014-01-01

    of thirty female pigs (body weight 63·1 (sem 4·4) kg) were fed a low-DF, high-fat Western-style control diet (WSD), an AX-rich diet (AXD) or a RS-rich diet (RSD) for 3 weeks. Diet significantly affected the digestibility of DM, protein, fat, NSP and NSP components, and the arabinose:xylose ratio, as well......The effects of a high level of dietary fibre (DF) either as arabinoxylan (AX) or resistant starch (RS) on digestion processes, SCFA concentration and pool size in various intestinal segments and on the microbial composition in the faeces were studied in a model experiment with pigs. A total...

  10. The Peroxidase/H2O2 System as a Free Radical-Generating Agent for Gelling Maize Bran Arabinoxylans: Rheological and Structural Properties

    Directory of Open Access Journals (Sweden)

    Erika Salas-Muñoz

    2011-10-01

    Full Text Available The oxidative gelation of maize bran arabinoxylans (MBAX using a peroxidase/H2O2 system as a free radical-generating agent was investigated. The peroxidase/H2O2 system led to the formation of dimers and trimer of ferulic acid as covalent cross-link structures in the MBAX network. MBAX gels at 4% (w/v presented a storage modulus of 180 Pa. The structural parameters of MBAX gels were calculated from swelling experiments. MBAX gels presented a molecular weight between two cross-links (Mc, a cross-linking density (ρc and a mesh size (x of 49 × 103 g/mol, 30 × 10−6 mol/cm3 and 193 nm, respectively.

  11. A randomised, double-blind, placebo controlled cross-over study to determine the gastrointestinal effects of consumption of arabinoxylan-oligosaccharides enriched bread in healthy volunteers

    Directory of Open Access Journals (Sweden)

    Walton Gemma E

    2012-06-01

    Full Text Available Abstract Background Prebiotics are food ingredients, usually non-digestible oligosaccharides, that are selectively fermented by populations of beneficial gut bacteria. Endoxylanases, altering the naturally present cereal arabinoxylans, are commonly used in the bread industry to improve dough and bread characteristics. Recently, an in situ method has been developed to produce arabinoxylan-oligosaccharides (AXOS at high levels in breads through the use of a thermophilic endoxylanase. AXOS have demonstrated potentially prebiotic properties in that they have been observed to lead to beneficial shifts in the microbiota in vitro and in murine, poultry and human studies. Methods A double-blind, placebo controlled human intervention study was undertaken with 40 healthy adult volunteers to assess the impact of consumption of breads with in situ produced AXOS (containing 2.2 g AXOS compared to non-endoxylanase treated breads. Volatile fatty acid concentrations in faeces were assessed and fluorescence in situ hybridisation was used to assess changes in gut microbial groups. Secretory immunoglobulin A (sIgA levels in saliva were also measured. Results Consumption of AXOS-enriched breads led to increased faecal butyrate and a trend for reduced iso-valerate and fatty acids associated with protein fermentation. Faecal levels of bifidobacteria increased following initial control breads and remained elevated throughout the study. Lactobacilli levels were elevated following both placebo and AXOS-breads. No changes in salivary secretory IgA levels were observed during the study. Furthermore, no adverse effects on gastrointestinal symptoms were reported during AXOS-bread intake. Conclusions AXOS-breads led to a potentially beneficial shift in fermentation end products and are well tolerated.

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

    Science.gov (United States)

    Russo, Matias; Fabersani, Emanuel; Abeijón-Mukdsi, María C.; Ross, Romina; Fontana, Cecilia; Benítez-Páez, Alfonso; Gauffin-Cano, Paola; Medina, Roxana B.

    2016-01-01

    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. PMID:27399766

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

    Science.gov (United States)

    Russo, Matias; Fabersani, Emanuel; Abeijón-Mukdsi, María C; Ross, Romina; Fontana, Cecilia; Benítez-Páez, Alfonso; Gauffin-Cano, Paola; Medina, Roxana B

    2016-01-01

    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. PMID:27399766

  14. Glutathione S-transferases in human liver cancer.

    OpenAIRE

    Hayes, P C; May, L.; Hayes, J. D.; Harrison, D J

    1991-01-01

    An immunohistochemical study of glutathione S-transferase (GST) expression in hepatocellular carcinoma and cholangiocarcinoma is described. Unlike most animal models of hepatic malignancy pi class GST was not consistently overexpressed in hepatocellular carcinoma. This tumour type either predominantly expressed alpha class GST or failed to express GST. By contrast, cholangiocarcinoma always expressed pi class GST, presumably reflecting the tissue of origin, since in human biliary epithelium p...

  15. Analysis of the glutathione S-transferase (GST) gene family

    OpenAIRE

    Nebert Daniel W; Vasiliou Vasilis

    2004-01-01

    Abstract The glutathione S-transferase (GST) gene family encodes genes that are critical for certain life processes, as well as for detoxication and toxification mechanisms, via conjugation of reduced glutathione (GSH) with numerous substrates such as pharmaceuticals and environmental pollutants. The GST genes are upregulated in response to oxidative stress and are inexplicably overexpressed in many tumours, leading to problems during cancer chemotherapy. An analysis of the GST gene family in...

  16. Proton mobilities in crambin and glutathione S-transferase

    Science.gov (United States)

    Wanderlingh, U. N.; Corsaro, C.; Hayward, R. L.; Bée, M.; Middendorf, H. D.

    2003-08-01

    Using a neutron backscattering spectrometer, the temperature dependence of mean-square atomic displacements derived from window-integrated quasielastic spectra was measured for two D 2O-hydrated proteins: crambin and glutathione S-transferase. Analyses show that the anharmonic dynamics observed around and above 200 K is consistent with a description in terms of proton/deuteron jumps within asymmetric double-minimum potentials. Also determined were activation energies along with estimates of effective masses and average oscillator energies.

  17. Purification and properties of glutathione transferase from Issatchenkia orientalis.

    OpenAIRE

    Tamaki, H.; Kumagai, H.; Tochikura, T

    1989-01-01

    Glutathione transferase (GST) (EC 2.5.1.18) was purified from a cell extract of Issatchenkia orientalis, and two GST isoenzymes were isolated. They had molecular weights of 37,500 and 40,000 and were designated GST Y-1 and GST Y-2, respectively. GST Y-1 and GST Y-2 gave single bands with molecular weights of 22,000 and 23,500, respectively, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. GST Y-1 and GST Y-2 were immunologically distinguished from each other. GST Y-1 showed speci...

  18. 21 CFR 862.1315 - Galactose-1-phosphate uridyl transferase test system.

    Science.gov (United States)

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1315 Galactose-1-phosphate uridyl transferase test system. (a)...

  19. Suppressive effects of quercetin-3-O-(6″-Feruloyl)-β-D-galactopyranoside on adipogenesis in 3T3-L1 preadipocytes through down-regulation of PPARγ and C/EBPα expression.

    Science.gov (United States)

    Yang, Lei; Li, Xiao-Fan; Gao, Lei; Zhang, Ya-Ou; Cai, Guo-Ping

    2012-03-01

    Obesity is a chronic, costly disease, and flavonoids such as quercetin have been proven to play protective roles against it. This study investigated the suppressive effect of quercetin-3-O-(6″-feruloyl)-β-D-galactopyranoside (QFG) on adipogenesis of 3T3-L1 preadipocytes. Quercetin-3-O-(6″-feruloyl)-β-D-galactopyranoside and quercetin were both extracted from Psidium guajava (Myrtaceae, commonly known as guava) leaves and were evaluated for their suppressive effect on adipogenesis by means of oil red O staining and triglyceride assay. It was shown that QFG inhibited adipogenesis in a dose- and time-dependent manner, and it exerted a stronger effect than did quercetin at the same concentration. Quantitative real-time polymerase chain reaction and western blotting were conducted to further examine the differentiation expression of marker genes and transcriptional factors. Both mRNA and protein expression of the key adipogenic transcriptional factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT (cytidine-cytidine-adenosine-adenosine-thymidine)/enhancer-binding protein alpha (C/EBPα), were inhibited by QFG. Moreover, the mRNA expression patterns of key participants in the Wnt-β-catenin pathway were not altered during the QFG-induced adipogenesis inhibition. These results suggest that QFG effectively suppresses adipogenesis and that it exerts its role mainly through the significant down-regulation of PPARγ and C/EBPα and, probably, via a Wnt-β-catenin independent pathway.

  20. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  1. Electrochemical evaluation of glutathione S-transferase kinetic parameters.

    Science.gov (United States)

    Enache, Teodor Adrian; Oliveira-Brett, Ana Maria

    2015-02-01

    Glutathione S-transferases (GSTs), are a family of enzymes belonging to the phase II metabolism that catalyse the formation of thioether conjugates between the endogenous tripeptide glutathione and xenobiotic compounds. The voltammetric behaviour of glutathione (GSH), 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione S-transferase (GST), as well as the catalytic conjugation reaction of GSH to CDNB by GST was investigated at room temperature, T=298.15K (25°C), at pH6.5, for low concentration of substrates and enzyme, using differential pulse (DP) voltammetry at a glassy carbon electrode. Only GSH can be oxidized; a sensitivity of 0.14nA/μM and a LOD of 6.4μM were obtained. The GST kinetic parameter electrochemical evaluation, in relation to its substrates, GSH and CDNB, using reciprocal Michaelis-Menten and Lineweaver-Burk double reciprocal plots, was determined. A value of KM~100μM was obtained for either GSH or CDNB, and Vmax varied between 40 and 60μmol/min per mg of GST.

  2. Ingestion of a novel galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex affected growth performance and fermentative and immunological characteristics of broiler chicks challenged with Salmonella typhimurium.

    Science.gov (United States)

    Faber, T A; Dilger, R N; Iakiviak, M; Hopkins, A C; Price, N P; Fahey, G C

    2012-09-01

    Fermentable carbohydrates may enhance the ability of the gastrointestinal tract to defend against a pathogenic infection. We hypothesized that a galactoglucomannan oligosaccharide-arabinoxylan (GGMO-AX) complex would positively affect immune status and prevent colonization and shedding in Salmonella typhimurium-infected chicks. Using a completely randomized design, 1-d-old commercial broiler chicks (n = 240 chicks; 4 replications/treatment; 5 chicks/replication) were assigned to 1 of 6 dietary treatments differing in concentration of GGMO-AX (0, 1, 2, or 4%) or containing 2% Safmannan or 2% short-chain fructooligosaccharides. Cellulose was used to make diets iso-total dietary fiber. On d 10 posthatch, an equal number of chicks on each diet were inoculated with either phosphate-buffered saline (sham control) or Salmonella typhimurium (1 × 10(8) cfu). All birds were euthanized on d 10 postinoculation (PI) for collection of intestinal contents and select tissues. Body weight gain and feed intake of chicks were greater (P Salmonella typhimurium populations on d 5 and 10 PI, and ileal and cecal Salmonella typhimurium populations, tended to be affected (P Salmonella typhimurium virulence was suppressed. Dietary supplementation with GGMO-AX resulted in prebiotic-like effects but did not limit Salmonella typhimurium intestinal colonization or shedding, but possibly decreased the virulence of Salmonella typhimurium within the digestive tract.

  3. Arabinoxylan rice bran (MGN-3/Biobran) provides protection against whole-body γ-irradiation in mice via restoration of hematopoietic tissues

    International Nuclear Information System (INIS)

    The aim of the current study is to examine the protective effect of MGN-3 on overall maintenance of hematopoietic tissue after γ-irradiation. MGN-3 is an arabinoxylan from rice bran that has been shown to be a powerful antioxidant and immune modulator. Swiss albino mice were treated with MGN-3 prior to irradiation and continued to receive MGN-3 for 1 or 4 weeks. Results were compared with mice that received radiation (5 Gy γ rays) only, MGN-3 (40 mg/kg) only and control mice (receiving neither radiation nor MGN-3). At 1 and 4 weeks post-irradiation, different hematological, histopathological and biochemical parameters were examined. Mice exposed to irradiation alone showed significant depression in their complete blood count (CBC) except for neutrophilia. Additionally, histopathological studies showed hypocellularity of their bone marrow, as well as a remarkable decrease in splenic weight/relative size and in number of megakaryocytes. In contrast, pre-treatment with MGN-3 resulted in protection against irradiation-induced damage to the CBC parameters associated with complete bone marrow cellularity, as well as protection of the aforementioned splenic changes. Furthermore, MGN-3 exerted antioxidative activity in whole-body irradiated mice, and provided protection from irradiation-induced loss of body and organ weight. In conclusion, MGN-3 has the potential to protect progenitor cells in the bone marrow, which suggests the possible use of MGN-3/Biobran as an adjuvant treatment to counteract the severe adverse side effects associated with radiation therapy

  4. Spontaneous and 5-azacytidine-induced reexpression of ornithine carbamoyl transferase in hepatoma cells.

    OpenAIRE

    Delers, A; Szpirer, J; Szpirer, C; Saggioro, D.

    1984-01-01

    Rat hepatoma cells that do not synthesize the hepatic enzyme ornithine carbamoyl transferase spontaneously give rise to producing cells at a low frequency. Reexpression of this differentiation trait is strongly increased by 5-azacytidine treatment, suggesting that hypermethylation plays a critical role in the impaired expression of the ornithine carbamoyl transferase gene in hepatoma cells.

  5. From glutathione transferase to pore in a CLIC

    CERN Document Server

    Cromer, B A; Morton, C J; Parker, M W; 10.1007/s00249-002-0219-1

    2002-01-01

    Many plasma membrane chloride channels have been cloned and characterized in great detail. In contrast, very little is known about intracellular chloride channels. Members of a novel class of such channels, called the CLICs (chloride intracellular channels), have been identified over the last few years. A striking feature of the CLIC family of ion channels is that they can exist in a water- soluble state as well as a membrane-bound state. A major step forward in understanding the functioning of these channels has been the recent crystal structure determination of one family member, CLIC1. The structure confirms that CLICs are members of the glutathione S- transferase superfamily and provides clues as to how CLICs can insert into membranes to form chloride channels. (69 refs).

  6. Pleiotropic functions of glutathione S-transferase P.

    Science.gov (United States)

    Zhang, Jie; Grek, Christina; Ye, Zhi-Wei; Manevich, Yefim; Tew, Kenneth D; Townsend, Danyelle M

    2014-01-01

    Glutathione S-transferase P (GSTP) is one member of the GST superfamily that is prevalently expressed in mammals. Known to possess catalytic activity through deprotonating glutathione allowing formation of thioether bonds with electrophilic substrates, more recent discoveries have broadened our understanding of the biological roles of this protein. In addition to catalytic detoxification, other properties so far ascribed to GSTP include chaperone functions, regulation of nitric oxide pathways, regulation of a variety of kinase signaling pathways, and participation in the forward reaction of protein S-glutathionylation. The expression of GSTP has been linked with cancer and other human pathologies and more recently even with drug addiction. With respect to human health, polymorphic variants of GSTP may determine individual susceptibility to oxidative stress and/or be critical in the design and development of drugs that have used redox pathways as a discovery platform.

  7. Glutathione analogue sorbents selectively bind glutathione S-transferase isoenzymes.

    Science.gov (United States)

    Castro, V M; Kelley, M K; Engqvist-Goldstein, A; Kauvar, L M

    1993-06-01

    Novel affinity sorbents for glutathione S-transferases (GSTs) were created by binding glutathione (GSH) analogues to Sepharose 6B. The GSH molecule was modified at the glycine moiety and at the group attached to the sulphur of cysteine. When tested by affinity chromatography in a flow-through microplate format, several of these sorbents selectively bound GST isoenzymes. gamma E-C(Hx)-phi G (glutathione with a hexyl moiety bound to cysteine and phenylglycine substituted for glycine) specifically bound rat GST 7-7, the Pi-class isoenzyme, from liver, kidney and small intestine. gamma E-C(Bz)-beta A (benzyl bound to cysteine and beta-alanine substituted for glycine) was highly selective for rat subunits 3 and 4, which are Mu-class isoenzymes. By allowing purification of the isoenzymes under mild conditions that preserve activity, the novel sorbents should be useful in characterizing the biological roles of GSTs in both normal animal and cancer tissues.

  8. Ghrelin O-Acyl Transferase: Bridging Ghrelin and Energy Homeostasis

    Directory of Open Access Journals (Sweden)

    Andrew Shlimun

    2011-01-01

    Full Text Available Ghrelin O-acyl transferase (GOAT is a recently identified enzyme responsible for the unique n-acyl modification of ghrelin, a multifunctional metabolic hormone. GOAT structure and activity appears to be conserved from fish to man. Since the acyl modification is critical for most of the biological actions of ghrelin, especially metabolic functions, GOAT emerged as a very important molecule of interest. The research on GOAT is on the rise, and several important results reiterating its significance have been reported. Notable among these discoveries are the identification of GOAT tissue expression patterns, effects on insulin secretion, blood glucose levels, feeding, body weight, and metabolism. Several attempts have been made to design and test synthetic compounds that can modulate endogenous GOAT, which could turn beneficial in favorably regulating whole body energy homeostasis. This paper will focus to provide an update on recent advances in GOAT research and its broader implications in the regulation of energy balance.

  9. A search for synbiotics: effects of enzymatically modified arabinoxylan and Butyrivibrio fibrisolvens on short-chain fatty acids in the cecum content and plasma of rats

    DEFF Research Database (Denmark)

    Nielsen, Tina Skau; Jensen, Bent Borg; Purup, Stig;

    2016-01-01

    ) versus a Western-style control diet (WSD) low in dietary fiber with or without orally administrated Butyrivibrio fibrisolvens, a butyrate producer, on the SCFA pool in the cecal content and feces and the SCFA concentration in the blood of rats. The pool of acetate, butyrate and total SCFA was more than......Identification of dietary strategies to increase large intestinal production and absorption of short-chain fatty acids (SCFAs), especially butyrate, is of great interest due to the possible health promoting effects. We explored the effect of an enzymatically modified arabinoxylan-rich diet (EAXD...

  10. Nuclear translocation of glutathione transferase omega is a progression marker in Barrett's esophagus

    DEFF Research Database (Denmark)

    Piaggi, Simona; Marchi, Santino; Ciancia, Eugenio;

    2009-01-01

    fraction of BE patients. This study was aimed to investigate the possible role of glutathione-S-transferase-omega 1 (GSTO1), a recently discovered member of the glutathione-S-transferase family, as a progression marker in the Barrett's disease in order to improve the diagnosis of Ni...... equally divided between nuclear, cytoplasmic and diffuse staining (2 each, respectively). Experiments in vitro showed that in human HeLa cancer cells, GSTO1 translocates into the nucleus as a consequence of heath shock. These findings suggested that the nuclear translocation of glutathione-S-transferase...

  11. Glutathione Transferase GSTπ In Breast Tumors Evaluated By Three Techniques

    Directory of Open Access Journals (Sweden)

    Rafael Molina

    1993-01-01

    Full Text Available The glutathione transferases are involved in intracellular detoxification reactions. One of these, GSTπ, is elevated in some breast cancer cells, particularly cells selected for resistance to anticancer agents. We evaluated GSTπ expression in 60 human breast tumors by three techniques, immunohistochemistry, Northern hybridization, and Western blot analysis. There was a significant positive correlation between the three methods, with complete concordance seen in 64% of the tumors. There was strong, inverse relationship between GSTπ expression and steroid receptor status with all of the techniques utili zed. [n addition, there was a trend toward higher GSTπ expression in poorly differentiated tumors, but no correlation was found between tumor GSTπ content and DNA ploidy or %S-phase. GSTπ expression was also detected in adjacent benign breast tissue as well as infiltrating lymphocytes; this expression may contribute to GSTπ measurements using either Northern hybridization or Western blot analysis. These re sults suggest that immunohistochemistry is the method of choice for measuring GSTπ in breast tumors.

  12. Benzene oxide is a substrate for glutathione S-transferases.

    Science.gov (United States)

    Zarth, Adam T; Murphy, Sharon E; Hecht, Stephen S

    2015-12-01

    Benzene is a known human carcinogen which must be activated to benzene oxide (BO) to exert its carcinogenic potential. BO can be detoxified in vivo by reaction with glutathione and excretion in the urine as S-phenylmercapturic acid. This process may be catalyzed by glutathione S-transferases (GSTs), but kinetic data for this reaction have not been published. Therefore, we incubated GSTA1, GSTT1, GSTM1, and GSTP1 with glutathione and BO and quantified the formation of S-phenylglutathione. Kinetic parameters were determined for GSTT1 and GSTP1. At 37 °C, the putative Km and Vmax values for GSTT1 were 420 μM and 450 fmol/s, respectively, while those for GSTP1 were 3600 μM and 3100 fmol/s. GSTA1 and GSTM1 did not exhibit sufficient activity for determination of kinetic parameters. We conclude that GSTT1 is a critical enzyme in the detoxification of BO and that GSTP1 may also play an important role, while GSTA1 and GSTM1 seem to be less important.

  13. Inactivation of Anopheles gambiae Glutathione Transferase ε2 by Epiphyllocoumarin

    Directory of Open Access Journals (Sweden)

    Patience Marimo

    2016-01-01

    Full Text Available Glutathione transferases (GSTs are part of a major family of detoxifying enzymes that can catalyze the reductive dehydrochlorination of dichlorodiphenyltrichloroethane (DDT. The delta and epsilon classes of insect GSTs have been implicated in conferring resistance to this insecticide. In this study, the inactivation of Anopheles gambiae GSTε2 by epiphyllocoumarin (Tral 1 was investigated. Recombinant AgGSTε2 was expressed in Escherichia coli cells containing a pET3a-AGSTε2 plasmid and purified by affinity chromatography. Tral 1 was shown to inactivate GSTε2 both in a time-dependent manner and in a concentration-dependent manner. The half-life of GSTε2 in the presence of 25 μM ethacrynic acid (ETA was 22 minutes and with Tral 1 was 30 minutes, indicating that Tral 1 was not as efficient as ETA as an inactivator. The inactivation parameters kinact and KI were found to be 0.020 ± 0.001 min−1 and 7.5 ± 2.1 μM, respectively, after 90 minutes of incubation. Inactivation of GSTε2 by Tral 1 implies that Tral 1 covalently binds to this enzyme in vitro and would be expected to exhibit time-dependent effects on the enzyme in vivo. Tral 1, therefore, would produce irreversible effects when used together with dichlorodiphenyltrichloroethane (DDT in malaria control programmes where resistance is mediated by GSTs.

  14. Glutathione S-transferase, incense burning and asthma in children.

    Science.gov (United States)

    Wang, I-J; Tsai, C-H; Chen, C-H; Tung, K-Y; Lee, Y L

    2011-06-01

    Incense burning is a popular practice in many family homes and temples. However, little is known about the effects of indoor incense burning and genetic polymorphisms on asthma. This study evaluated the effects of indoor incense burning and glutathione S-transferase (GST) genetic polymorphisms on asthma and wheeze. In 2007, 3,764 seventh-grade schoolchildren (mean±sd age 12.42±0.65 yrs) were evaluated using a standard questionnaire for information about respiratory symptoms and environmental exposures. Multiple logistic regressions were performed to assess the association between GST polymorphisms and incense burning frequency on asthma and wheeze, after adjusting for potential confounders. The frequency of incense burning at home was associated with increased risk of current asthma (p=0.05), medication use (p=0.03) and exercise wheeze (p=0.001). GST1 (GSTT1) null genotypes were associated with current asthma (OR 1.43, 95% CI 1.00-2.04) and medication use (OR 1.46, 95% CI 1.01-2.22). GSTT1 showed a significant interactive effect with incense burning on current asthma, current wheeze and nocturnal wheeze. The frequency of incense burning was associated with increased risk of current asthma, medication use, lifetime wheeze, nocturnal wheeze and exercise wheeze in an exposure-response manner among children with GSTT1 null genotype (pIncense burning is a risk factor for asthma and wheezing, especially in GSTT1 genetically susceptible children.

  15. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity

    DEFF Research Database (Denmark)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T;

    2014-01-01

    Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms....... Surprisingly, molecular probes to monitor GalNAc-transferase activity are lacking and there exist no effective global or isoform-specific inhibitors. Here we describe the development of T2- and T3-isoform specific fluorescence sensors that traffic in the secretory pathway. Each sensor yielded little signal...... in both the study of GalNAc-transferase regulation and in high-throughput screening for potential therapeutic regulators of specific GalNAc-transferases....

  16. Serum fucosyl transferase activity and serum fucose levels as diagnostic tools in malignancy.

    Directory of Open Access Journals (Sweden)

    Sen,Umi

    1983-12-01

    Full Text Available Glycoproteins play a significant role in neoplastic transformations. Both the levels of fucose and the activity of fucosyl transferase, which mediates the assembly of the oligosaccharide moieties of the glycoprotein chains, have been found to be elevated in neoplastic conditions. Since these elevations are common features of a variety of neoplastic cells, these two have been designated as non-specific markers of malignancy. In the present study, the fucose level and fucosyl transferase activity were determined in the sera of cancer patients and an attempt was made to establish a relationship between the two. It was found that both the fucose levels and fucosyl transferase activities showed considerable elevation in the five cancer groups studied, establishing them as useful diagnostic parameters. However, it was also observed that the rate of increased fucosyl transferase activity was not fully reflected in the resulting serum fucose levels in a few cases.

  17. Serum fucosyl transferase activity and serum fucose levels as diagnostic tools in malignancy.

    OpenAIRE

    Sen,Umi; Guha,Subhas; Chowdhury, J Roy

    1983-01-01

    Glycoproteins play a significant role in neoplastic transformations. Both the levels of fucose and the activity of fucosyl transferase, which mediates the assembly of the oligosaccharide moieties of the glycoprotein chains, have been found to be elevated in neoplastic conditions. Since these elevations are common features of a variety of neoplastic cells, these two have been designated as non-specific markers of malignancy. In the present study, the fucose level and fucosyl transferase activi...

  18. Glutathione S-transferase isoenzymes in relation to their role in detoxification of xenobiotics.

    OpenAIRE

    Vos, R.M.E.

    1989-01-01

    The glutathione S-transferases (GST) are a family of isoenzymes serving a major part in the biotransformation of many reactive compounds. The isoenzymes from rat, man and mouse are divided into three classes, alpha, mu and pi, on the basis of similar structural and enzymatic properties.The main function of the glutathione S-transferases isthe catalysisof the conjugation of electrophilic, hydrophobic compounds with the tripeptide glutathione (GSH). In addition, some of the isoenzymes are capab...

  19. An efficient arabinoxylan-debranching α-L-arabinofuranosidase of family GH62 from Aspergillus nidulans contains a secondary carbohydrate binding site.

    Science.gov (United States)

    Wilkens, Casper; Andersen, Susan; Petersen, Bent O; Li, An; Busse-Wicher, Marta; Birch, Johnny; Cockburn, Darrell; Nakai, Hiroyuki; Christensen, Hans E M; Kragelund, Birthe B; Dupree, Paul; McCleary, Barry; Hindsgaul, Ole; Hachem, Maher Abou; Svensson, Birte

    2016-07-01

    An α-L-arabinofuranosidase of GH62 from Aspergillus nidulans FGSC A4 (AnAbf62A-m2,3) has an unusually high activity towards wheat arabinoxylan (WAX) (67 U/mg; k cat = 178/s, K m = 4.90 mg/ml) and arabinoxylooligosaccharides (AXOS) with degrees of polymerisation (DP) 3-5 (37-80 U/mg), but about 50 times lower activity for sugar beet arabinan and 4-nitrophenyl-α-L-arabinofuranoside. α-1,2- and α-1,3-linked arabinofuranoses are released from monosubstituted, but not from disubstituted, xylose in WAX and different AXOS as demonstrated by NMR and polysaccharide analysis by carbohydrate gel electrophoresis (PACE). Mutants of the predicted general acid (Glu(188)) and base (Asp(28)) catalysts, and the general acid pK a modulator (Asp(136)) lost 1700-, 165- and 130-fold activities for WAX. WAX, oat spelt xylan, birchwood xylan and barley β-glucan retarded migration of AnAbf62A-m2,3 in affinity electrophoresis (AE) although the latter two are neither substrates nor inhibitors. Trp(23) and Tyr(44), situated about 30 Å from the catalytic site as seen in an AnAbf62A-m2,3 homology model generated using Streptomyces thermoviolaceus SthAbf62A as template, participate in carbohydrate binding. Compared to wild-type, W23A and W23A/Y44A mutants are less retarded in AE, maintain about 70 % activity towards WAX with K i of WAX substrate inhibition increasing 4-7-folds, but lost 77-96 % activity for the AXOS. The Y44A single mutant had less effect, suggesting Trp(23) is a key determinant. AnAbf62A-m2,3 seems to apply different polysaccharide-dependent binding modes, and Trp(23) and Tyr(44) belong to a putative surface binding site which is situated at a distance of the active site and has to be occupied to achieve full activity. PMID:26946172

  20. Glutathione transferase classes alpha, pi, and mu: GSH activation mechanism.

    Science.gov (United States)

    Dourado, Daniel F A R; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2010-10-14

    Since the early 1960s, glutathione transferases (GSTs) have been described as detoxification enzymes. In fact, GSTs are the most important enzymes involved in the metabolism of electrophilic xenobiotic/endobiotic compounds. These enzymes are able to catalyze the nucleophilic addition of glutathione (GSH) sulfur thiolate to a wide range of electrophilic substrates, building up a less toxic and more soluble compound. Cytosolic classes alpha, pi, and mu are the most extensively studied GSTs. However, many of the catalytic events are still poorly understood. In the present work, we have resorted to density functional theory (DFT) and to potential of mean force (PMF) calculations to determine the GSH activation mechanism of GSTP1-1 and GSTM1-1 isoenzymes. For the GSTP1-1 enzyme, we have demonstrated that a water molecule, after an initial conformational rearrangement of GSH, can assist a proton transfer between the GSH cysteine thiol (GSH-SH) and the GSH glutamate alpha carboxylate (GSH-COO(-)) groups. The energy barrier associated with the proton transfer is 11.36 kcal·mol(-1). The GSTM1-1 enzyme shows a completely different behavior from the previous isoenzyme. In this case, two water molecules, positioned between the GSH-SH and the ξ N atom of His107, working like a bridge, are able to promote the proton transfer between these two active groups with an energy barrier of 7.98 kcal·mol(-1). All our results are consistent with all the enzymes kinetics and mutagenesis experimental studies.

  1. Analysis of Arabidopsis glutathione-transferases in yeast.

    Science.gov (United States)

    Krajewski, Matthias P; Kanawati, Basem; Fekete, Agnes; Kowalski, Natalie; Schmitt-Kopplin, Philippe; Grill, Erwin

    2013-07-01

    The genome of Arabidopsis thaliana encodes 54 functional glutathione transferases (GSTs), classified in seven clades. Although plant GSTs have been implicated in the detoxification of xenobiotics, such as herbicides, extensive redundancy within this large gene family impedes a functional analysis in planta. In this study, a GST-deficient yeast strain was established as a system for analyzing plant GSTs that allows screening for GST substrates and identifying substrate preferences within the plant GST family. To this end, five yeast genes encoding GSTs and GST-related proteins were simultaneously disrupted. The resulting yeast quintuple mutant showed a strongly reduced conjugation of the GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). Consistently, the quintuple mutant was hypersensitive to CDNB, and this phenotype was complemented by the inducible expression of Arabidopsis GSTs. The conjugating activity of the plant GSTs was assessed by in vitro enzymatic assays and via analysis of exposed yeast cells. The formation of glutathione adducts with dinitrobenzene was unequivocally verified by stable isotope labeling and subsequent accurate ultrahigh-resolution mass spectrometry (ICR-FTMS). Analysis of Arabidopsis GSTs encompassing six clades and 42 members demonstrated functional expression in yeast by using CDNB and NBD-Cl as model substrates. Subsequently, the established yeast system was explored for its potential to screen the Arabidopsis GST family for conjugation of the fungicide anilazine. Thirty Arabidopsis GSTs were identified that conferred increased levels of glutathionylated anilazine. Efficient anilazine conjugation was observed in the presence of the phi, tau, and theta clade GSTs including AtGSTF2, AtGSTF4, AtGSTF6, AtGSTF8, AtGSTF10, and AtGSTT2, none of which had previously been known to contribute to fungicide detoxification. ICR-FTMS analysis of yeast extracts allowed the simultaneous detection and

  2. 结构预测及分子对接方法研究几种水解产物对新阿魏酸酯酶的抑制作用%Structure Prediction and Molecular Docking Studies on the Inhibitory Effect of Several Hydrolyzate on a Novel Feruloyl Esterase

    Institute of Scientific and Technical Information of China (English)

    程凡升; 张茂秋; 程凡杰; 生吉萍; 陈婧雨; 郑鄢燕; 申琳

    2012-01-01

    Feruloyl esterases, one of the key enzymes in biomass degradation, show great prospects in food, textile, forge and pulp industries. In this study, a feruloyl esterase with low sequence identity was studied, which was originated from China Holstein cow rumen metagenomic library. Possible catalytic mechanisms were discussed based on conserved domains and tertiary structure modelling. Molecular docking studies show that the predicted affinity energy exhibits liner relations to experimental Vmax values and hydrogen bond may play a key role on catalytic efficiency. In addition, molecular docking study indicates that L-arabinobiose, D-xylose, D-glucose and trans-ferulic acid may have inhibitory effect on feruloyl esterase activity and the inhibition studies verify this hypothesis. This study may pave a way on rational design of feruloyl esterase and provide guidance on ferulic acid production from lignocellulose materials.%应用基于生物信息学的蛋白质结构预测方法,探讨了来源于荷斯坦奶牛瘤胃宏基因组文库的一个新型阿魏酸酯酶( FAE-SH1)的结构及可能的催化机制.同时通过对该酶的预测结构与4种模式底物的对接研究发现,实验所测得酶促反应动力参数Vmax与对接的亲和能存在线性关系,底物与酶形成的氢键可能是影响催化效率的关键因素.同时,本研究发现D-木糖、L-阿拉伯糖、D-葡萄糖及阿魏酸能够对FAE-SH1的水解反应产生抑制作用,并对其进行了验证.

  3. Characterization of glutathione-S-transferases in zebrafish (Danio rerio).

    Science.gov (United States)

    Glisic, Branka; Mihaljevic, Ivan; Popovic, Marta; Zaja, Roko; Loncar, Jovica; Fent, Karl; Kovacevic, Radmila; Smital, Tvrtko

    2015-01-01

    Glutathione-S-transferases (GSTs) are one of the key enzymes that mediate phase II of cellular detoxification. The aim of our study was a comprehensive characterization of GSTs in zebrafish (Danio rerio) as an important vertebrate model species frequently used in environmental research. A detailed phylogenetic analysis of GST superfamily revealed 27 zebrafish gst genes. Further insights into the orthology relationships between human and zebrafish GSTs/Gsts were obtained by the conserved synteny analysis. Expression of gst genes in six tissues (liver, kidney, gills, intestine, brain and gonads) of adult male and female zebrafish was determined using qRT-PCR. Functional characterization was performed on 9 cytosolic Gst enzymes after overexpression in E. coli and subsequent protein purification. Enzyme kinetics was measured for GSH and a series of model substrates. Our data revealed ubiquitously high expression of gstp, gstm (except in liver), gstr1, mgst3a and mgst3b, high expression of gsto2 in gills and ovaries, gsta in intestine and testes, gstt1a in liver, and gstz1 in liver, kidney and brain. All zebrafish Gsts catalyzed the conjugation of GSH to model GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and monochlorobimane (MCB), apart from Gsto2 and Gstz1 that catalyzed GSH conjugation to dehydroascorbate (DHA) and dichloroacetic acid (DCA), respectively. Affinity toward CDNB varied from 0.28 mM (Gstp2) to 3.69 mM (Gstm3), while affinity toward MCB was in the range of 5 μM (Gstt1a) to 250 μM (Gstp1). Affinity toward GSH varied from 0.27 mM (Gstz1) to 4.45 mM (Gstt1a). Turnover number for CDNB varied from 5.25s(-1) (Gstt1a) to 112s(-1) (Gstp2). Only Gst Pi enzymes utilized ethacrynic acid (ETA). We suggest that Gstp1, Gstp2, Gstt1a, Gstz1, Gstr1, Mgst3a and Mgst3b have important role in the biotransformation of xenobiotics, while Gst Alpha, Mu, Pi, Zeta and Rho classes are involved in the crucial physiological processes. In summary, this study provides the

  4. Glucomannan synthesis in pea epicotyls: the mannose and glucose transferases.

    Science.gov (United States)

    Piro, G; Zuppa, A; Dalessandro, G; Northcote, D H

    1993-01-01

    Membrane fractions and digitonin-solubilized enzymes prepared from stem segments isolated from the third internode of etiolated pea seedlings (Pisum sativum L. cv. Alaska) catalyzed the synthesis of a beta-1,4-[14C]mannan from GDP-D-[U-14C]-mannose, a mixed beta-1,3- and beta-1,4-[14C]glucan from GDP-D-[U-14C]-glucose and a beta-1,4-[14C]-glucomannan from both GDP-D-[U-14C]mannose and GDP-D-[U-14C]glucose. The kinetics of the membrane-bound and soluble mannan and glucan synthases were determined. The effects of ions, chelators, inhibitors of lipid-linked saccharides, polyamines, polyols, nucleotides, nucleoside-diphosphate sugars, acetyl-CoA, group-specific chemical probes, phospholipases and detergents on the membrane-bound mannan and glucan synthases were investigated. The beta-glucan synthase had different properties from other preparations which bring about the synthesis of beta-1,3-glucans (callose) and mixed beta-1,3- and beta-1,4- glucans and which use UDP-D-glucose as substrate. It also differed from xyloglucan synthase because in the presence of several concentrations of UDP-D-xylose in addition to GDP-D-glucose no xyloglucan was formed. Using either the membrane-bound or the soluble mannan synthase, GDP-D-glucose acted competitively in the presence of GDP-D-mannose to inhibit the incorporation of mannose into the polymer. This was not due to an inhibition of the transferase activity but was a result of the incorporation of glucose residues from GDP-D-glucose into a glucomannan. The kinetics and the composition of the synthesized glucomannan depended on the ratio of the concentrations of GDP-D-glucose and GDP-D-mannose that were available. Our data indicated that a single enzyme has an active centre that can use both GDP-D-mannose and GDP-D-glucose to bring about the synthesis of the heteropolysaccharide. PMID:7685647

  5. Enzymatic Hydrolysis of Wheat Arabinoxylan by a Recombinant "Minimal" Enzyme Cocktail Containing beta-Xylosidase and Novel endo-1,4-beta-Xylanase and alpha-L-Arabinofuranosidase Activities

    DEFF Research Database (Denmark)

    Sørensen, Hanne R.; Pedersen, Sven; Jørgensen, Christel T.;

    2007-01-01

    24 h at pH 5, 50 degrees C. A 10%:40%:50% mixture of Abf II, Abf III, and beta-xyl released 56 mg of arabinose and 91 mg of xylose per gram of vinasse dry matter after 24 h at pH 5, 50 degrees C. The optimal dosages of the "minimal" enzyme cocktails were determined to be 0.4, 0.3, and 0.2 g enzyme......This study describes the identification of the key enzyme activities required in a "minimal" enzyme cocktail able to catalyze hydrolysis of water-soluble and water-insoluble wheat arabinoxylan and whole vinasse, a fermentation effluent resulting from industrial ethanol manufacture from wheat...

  6. Alteration of glutathione S-transferase properties during the development of Micromelalopha troglodyta larvae (Lepidoptera: Notodontidae)

    Institute of Scientific and Technical Information of China (English)

    TANG Fang; ZHANG Xiu-bo; LIU Yu-sheng; GAO Xi-wu

    2011-01-01

    Micromelalopha troglodyta (Graeser) is an important pest ofpoplar in China. Glutathione S-transferases (GSTs) are known to beresponsible for adaptation mechanisms of M. Troglodyta. The activitiesand kinetic constants of glutathione S-transferases in M. Troglodyta werestudied. Significant differences in glutathione S-transferase activity andkinetic characteristics were observed among five instars of M. Troglodytalarvae. Furthermore, the inhibition of glutathione S-transferase activity infive instars by 24 inhibitors was conducted. The results show the inhibi-tion of GST activity of different instars by 24 inhibitors was different.For GST activity in the 1st instar chlorpyrifos, lambda-cyhalothrin,endosulfan, abamectin, fipronil and pyridaben were the best inhibitorstested, and for GST activity in the 2nd instar, tannic acid and quercetinwere the most potent inhibitors tested, and for GST activity in the 3rdinstar, the inhibitory effects of quercetin, chlorpyrifos andlambda-cyhalothrin were the highest, and for GST activity in the 4thinstar, quercetin and lambda-cyhalothrin were the best inhibitors, and theinhibitory effect of pboxim was the highest for GST activity in the 5thinstar. Our results show that glutathione S-transferases in different iustarsare qualitatively different in isozyme composition and thus different insensitivity to inhibitors.

  7. Expression of polypeptide GalNAc-transferases in stratified epithelia and squamous cell carcinomas

    DEFF Research Database (Denmark)

    Mandel, U; Hassan, H; Therkildsen, M H;

    1999-01-01

    GalNAc-T1, -T2, and -T3. Application of this panel of novel antibodies revealed that GalNAc- transferases are differentially expressed in different cell lines, in spermatozoa, and in oral mucosa and carcinomas. For example, GalNAc-T1 and -T2 but not -T3 were highly expressed in WI38 cells, and GalNAc......Mucin-type O-glycosylation is initiated by a large family of UDP-GalNAc: polypeptide N -acetyl-galactosaminyltransferases (GalNAc-transferases). Individual GalNAc-transferases appear to have different functions and Northern analysis indicates that they are differently expressed in different organs....... This suggests that O-glycosylation may vary with the repertoire of GalNAc-transferases expressed in a given cell. In order to study the repertoire of GalNAc-transferases in situ in tissues and changes in tumors, we have generated a panel of monoclonal antibodies (MAbs) with well defined specificity for human...

  8. Puromycin-rRNA interaction sites at the peptidyl transferase center

    DEFF Research Database (Denmark)

    Rodriguez-Fonseca, Christina; Phan, Hien; Long, Katherine Sarah;

    2000-01-01

    of puromycin. They include A2439, G2505, and G2553 for E. coli, and G2058, A2503, G2505, and G2553 for Hf. gibbonsii (using the E. coli numbering system). Reproducible enhanced reactivities were also observed at A508 and A1579 within domains I and III, respectively, of E. coli 23S rRNA. In further experiments......The binding site of puromycin was probed chemically in the peptidyl-transferase center of ribosomes from Escherichia coli and of puromycin-hypersensitive ribosomes from the archaeon Haloferax gibbonsii. Several nucleotides of the 23S rRNAs showed altered chemical reactivities in the presence......S rRNA. These data strongly support the concept that puromycin, along with other peptidyl-transferase antibiotics, in particular the streptogramin B drugs, bind to an RNA structural motif that contains several conserved and accessible base moieties of the peptidyl transferase loop region...

  9. Disparate Metabolic Responses in Mice Fed a High-Fat Diet Supplemented with Maize-Derived Non-Digestible Feruloylated Oligo- and Polysaccharides Are Linked to Changes in the Gut Microbiota.

    Directory of Open Access Journals (Sweden)

    Junyi Yang

    Full Text Available Studies have suggested links between colonic fermentation of dietary fibers and improved metabolic health. The objectives of this study were to determine if non-digestible feruloylated oligo- and polysaccharides (FOPS, a maize-derived dietary fiber, could counteract the deleterious effects of high-fat (HF feeding in mice and explore if metabolic benefits were linked to the gut microbiota. C57BL/6J mice (n = 8/group were fed a low-fat (LF; 10 kcal% fat, HF (62 kcal% fat, or HF diet supplemented with FOPS (5%, w/w. Pronounced differences in FOPS responsiveness were observed: four mice experienced cecal enlargement and enhanced short chain fatty acid production, indicating increased cecal fermentation (F-FOPS. Only these mice displayed improvements in glucose metabolism compared with HF-fed mice. Blooms in the gut microbial genera Blautia and Akkermansia were observed in three of the F-FOPS mice; these shifts were associated with reductions in body and adipose tissue weights compared with the HF-fed control mice. No improvements in metabolic markers or weights were detected in the four mice whose gut microbiota did not respond to FOPS. These findings demonstrate that FOPS-induced improvements in weight gain and metabolic health in mice depended on the ability of an individual's microbiota to ferment FOPS.

  10. Activity Detection of GalNAc Transferases by Protein-Based Fluorescence Sensors In Vivo.

    Science.gov (United States)

    Song, Lina; Bachert, Collin; Linstedt, Adam D

    2016-01-01

    Mucin-type O-glycosylation occurring in the Golgi apparatus is an important protein posttranslational modification initiated by up to 20 GalNAc-transferase isozymes with largely distinct substrate specificities. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and misregulation causes human diseases. Here we describe the use of protein-based fluorescence sensors that traffic in the secretory pathway to monitor GalNAc-transferase activity in living cells. The sensors can either be "pan" or isozyme specific. PMID:27632006

  11. Activity Detection of GalNAc Transferases by Protein-Based Fluorescence Sensors In Vivo.

    Science.gov (United States)

    Song, Lina; Bachert, Collin; Linstedt, Adam D

    2016-01-01

    Mucin-type O-glycosylation occurring in the Golgi apparatus is an important protein posttranslational modification initiated by up to 20 GalNAc-transferase isozymes with largely distinct substrate specificities. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and misregulation causes human diseases. Here we describe the use of protein-based fluorescence sensors that traffic in the secretory pathway to monitor GalNAc-transferase activity in living cells. The sensors can either be "pan" or isozyme specific.

  12. Origin and evolution of the Peptidyl Transferase Center from proto-tRNAs

    Directory of Open Access Journals (Sweden)

    Sávio T. Farias

    2014-01-01

    Full Text Available We tested the hypothesis of Tamura (2011 [3] that molecules of tRNA gave origin to ribosomes, particularly to the Peptidyl Transferase Center (PTC of the 23S ribosomal RNA. We reconstructed the ancestral sequences from all types of tRNA and compared them in their sequences with the current PTC of 23S ribosomal RNA from different organisms. We built an ancestral sequence of proto-tRNAs that showed a remarkable overall identity of 50.53% with the catalytic site of PTC. We conclude that the Peptidyl Transferase Center was indeed originated by the fusion of ancestral sequences of proto-tRNA.

  13. Purification and Biochemical Characterization of Glutathione S-Transferase from Down Syndrome and Normal Children Erythrocytes: A Comparative Study

    Science.gov (United States)

    Hamed, Ragaa R.; Maharem, Tahany M.; Abdel-Meguid, Nagwa; Sabry, Gilane M.; Abdalla, Abdel-Monem; Guneidy, Rasha A.

    2011-01-01

    Down syndrome (DS) is the phenotypic manifestation of trisomy 21. Our study was concerned with the characterization and purification of glutathione S-transferase enzyme (GST) from normal and Down syndrome (DS) erythrocytes to illustrate the difference in the role of this enzyme in the cell. Glutathione S-transferase and glutathione (GSH) was…

  14. The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations

    NARCIS (Netherlands)

    J.M. Flanagan; G. McMahon; S.H. Brendan Shia; P. Fitzpatrick; O. Tighe; C. O'Neill; P. Briones; L. Gort; L. Kozak; A. Magee; E. Naughten; B. Radomyska; M. Schwartz; J.S. Shin; W.M. Strobl; L.A. Tyfield; H.R. Waterham; H. Russell; G. Bertorelle; J.K.V. Reichardt; P.D. Mayne; D.T. Croke

    2010-01-01

    Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To bette

  15. Purification of human hepatic glutathione S-transferases and the development of a radioimmunoassay for their measurement in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, J.D.; Gilligan, D.; Beckett, G.J. (Edinburgh Univ. (UK). Dept. of Clinical Chemistry); Chapman, B.J. (Royal Infirmary, Edinburgh (UK))

    1983-10-31

    A purification scheme is described for six human hepatic glutathione S-transferases from a single liver. Five of the transferases comprised Ya monomers and had a molecular mass of 44000. The remaining enzyme comprised Yb monomers and had a molecular mass of 47000. Data are presented demonstrating that there are at least two distinct Ya monomers. A radioimmunoassay has been developed that has sufficient precision and sensitivity to allow direct measurement of glutathione S-transferase concentrations in unextracted plasma. A comparison of aminotransferase and glutathione S-transferase levels, in three patients who had taken a paracetamol overdose, indicated that glutathione S-transferase measurements provided a far more sensitive index of hepatocellular integrity than the more conventional aminotransferase measurements.

  16. Meat consumption, N-acetyl transferase 1 and 2 polymorphism and risk of breast cancer, in Danish postmenopausal women

    DEFF Research Database (Denmark)

    Egeberg, Rikke; Olsen, Anja; Autrup, Herman;

    2008-01-01

    total meat intake and red meat intake and breast cancer risk were confined to intermediate/fast N-acetyl transferase 2 acetylators (P-interaction=0.03 and 0.04). Our findings support an association between meat consumption and breast cancer risk and that N-acetyl transferase 2 polymorphism has......The aim of this study was to investigate whether polymorphisms in N-acetyl transferase 1 and 2 modify the association between meat consumption and risk of breast cancer. A nested case-control study was conducted among 24697 postmenopausal women included in the 'Diet, Cancer and Health' cohort study...... increment in intake. Compared with slow acetylators, the IRR (95% confidence interval) among fast N-acetyl transferase 1 acetylators was 1.43 (1.03-1.99) and 1.13 (0.83-1.54) among intermediate/fast N-acetyl transferase 2 acetylators. Interaction analyses revealed that the positive associations between...

  17. Glutathione S-transferase isoenzymes in relation to their role in detoxification of xenobiotics.

    NARCIS (Netherlands)

    Vos, R.M.E.

    1989-01-01

    The glutathione S-transferases (GST) are a family of isoenzymes serving a major part in the biotransformation of many reactive compounds. The isoenzymes from rat, man and mouse are divided into three classes, alpha, mu and pi, on the basis of similar structural and enzymatic properties.

  18. 21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

    Science.gov (United States)

    2010-04-01

    ... genetically modified cotton, oilseed rape, and tomatoes in accordance with the following prescribed conditions... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Aminoglycoside 3â²-phospho- transferase II. 573.130 Section 573.130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND...

  19. The role of glutathione S-transferase and claudin-1 gene polymorphisms in contact sensitization

    DEFF Research Database (Denmark)

    Ross-Hansen, K; Linneberg, A; Johansen, J D;

    2013-01-01

    BACKGROUND: Contact sensitization is frequent in the general population and arises from excessive or repeated skin exposure to chemicals and metals. However, little is known about its genetic susceptibility. OBJECTIVES: To determine the role of polymorphisms of glutathione S-transferase (GST) genes...

  20. Differential roles of tau class glutathione S-transferases in oxidative stress

    DEFF Research Database (Denmark)

    Kilili, Kimiti G; Atanassova, Neli; Vardanyan, Alla;

    2004-01-01

    The plant glutathione S-transferase BI-GST has been identified as a potent inhibitor of Bax lethality in yeast, a phenotype associated with oxidative stress and disruption of mitochondrial functions. Screening of a tomato two-hybrid library for BI-GST interacting proteins identified five homologous...

  1. Effect of glutathione S-transferases on the survival of patients with acute myeloid leukaemia

    DEFF Research Database (Denmark)

    Autrup, Judith; Hokland, Peter; Pedersen, Lars;

    2002-01-01

    The objective of the study was to investigate the effect of genetic polymorphisms in glutathione S-transferases (GST) on the survival of acute myeloid leukaemia patients receiving adriamycin induction therapy. A total of 89 patients were included in the study. Patients who carried at least one GSTM...

  2. Glutathione transferase activity and oocyte development in copepods exposed to toxic phytoplankton

    DEFF Research Database (Denmark)

    Kozlowsky-Suzuki, Betina; Koski, Marja; Hallberg, Eric;

    2009-01-01

    Organisms present a series of cellular mechanisms to avoid the effects of toxic compounds. Such mechanisms include the increase in activity of detoxification enzymes [e.g., 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST)I, which could explain the low retention of ingested...

  3. Preliminary X-ray crystallographic analysis of glutathione transferase zeta 1 (GSTZ1a-1a)

    Energy Technology Data Exchange (ETDEWEB)

    Boone, Christopher D.; Zhong, Guo; Smeltz, Marci; James, Margaret O., E-mail: mojames@ufl.edu; McKenna, Robert, E-mail: mojames@ufl.edu

    2014-01-21

    Crystals of glutathione transferase zeta 1 were grown and shown to diffract X-rays to 3.1 Å resolution. They belonged to space group P1, with unit-cell parameters a = 42.0, b = 49.6, c = 54.6 Å, α = 82.9, β = 69.9, γ = 73.4°.

  4. Inhibition of human glutathione S-transferase P1-1 by the flavonoid quercetin

    NARCIS (Netherlands)

    Zanden, J.J. van; Hamman, O.B.; Iersel, M.L.P.S. van; Boeren, S.; Cnubben, N.H.P.; Lo Bello, M.; Vervoort, J.; Bladeren, P.J. van; Rietjens, I.M.C.M.

    2003-01-01

    In the present study, the inhibition of human glutathione S-transferase P1-1 (GSTP1-1) by the flavonoid quercetin has been investigated. The results show a time- and concentration-dependent inhibition of GSTP1-1 by quercetin. GSTP1-1 activity is completely inhibited upon 1 h incubation with 100 μM q

  5. A practical fluorogenic substrate for high-throughput screening of glutathione S-transferase inhibitors.

    Science.gov (United States)

    Fujikawa, Yuuta; Morisaki, Fumika; Ogura, Asami; Morohashi, Kana; Enya, Sora; Niwa, Ryusuke; Goto, Shinji; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Inoue, Hideshi

    2015-07-21

    We report a new fluorogenic substrate for glutathione S-transferase (GST), 3,4-DNADCF, enabling the assay with a low level of nonenzymatic background reaction. Inhibitors against Noppera-bo/GSTe14 from Drosophila melanogaster were identified by high throughput screening using 3,4-DNADCF, demonstrating the utility of this substrate.

  6. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial euka

  7. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity.

    Science.gov (United States)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T; Clausen, Henrik; Linstedt, Adam D

    2014-10-31

    Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms. Surprisingly, molecular probes to monitor GalNAc-transferase activity are lacking and there exist no effective global or isoform-specific inhibitors. Here we describe the development of T2- and T3-isoform specific fluorescence sensors that traffic in the secretory pathway. Each sensor yielded little signal when glycosylated but was strongly activated in the absence of its glycosylation. Specificity of each sensor was assessed in HEK cells with either the T2 or T3 enzymes deleted. Although the sensors are based on specific substrates of the T2 and T3 enzymes, elements in or near the enzyme recognition sequence influenced their activity and required modification, which we carried out based on previous in vitro work. Significantly, the modified T2 and T3 sensors were activated only in cells lacking their corresponding isozymes. Thus, we have developed T2- and T3-specific sensors that will be valuable in both the study of GalNAc-transferase regulation and in high-throughput screening for potential therapeutic regulators of specific GalNAc-transferases.

  8. Antibiotic inhibition of the movement of tRNA substrates through a peptidyl transferase cavity

    DEFF Research Database (Denmark)

    Porse, B T; Rodriguez-Fonseca, C; Leviev, I;

    1996-01-01

    The present review attempts to deal with movement of tRNA substrates through the peptidyl transferase centre on the large ribosomal subunit and to explain how this movement is interrupted by antibiotics. It builds on the concept of hybrid tRNA states forming on ribosomes and on the observed movem...

  9. Habitual consumption of fruits and vegetables: associations with human rectal glutathione S-transferase

    NARCIS (Netherlands)

    Wark, P.A.; Grubben, M.J.A.L.; Peters, W.H.M.; Nagengast, F.M.; Kampman, E.; Kok, F.J.; Veer, van 't P.

    2004-01-01

    The glutathione (GSH)/glutathione S-transferase (GST) system is an important detoxification system in the gastrointestinal tract. A high activity of this system may benefit cancer prevention. The aim of the study was to assess whether habitual consumption of fruits and vegetables, especially citrus

  10. Glutathione-S-transferase genotype and p53 mutations in adenocarcinoma of the small intestine

    DEFF Research Database (Denmark)

    Pedersen, Lisbeth Nørum; Kærlev, Linda; Teglbjærg, Peter Stubbe;

    2003-01-01

    Adenocarcinoma of the small intestine (ASI) is a rare disease of unknown aetiology. The glutathione S-transferase M1 (GSTM1) enzyme catalyses the detoxification of compounds involved in carcinogenesis of adenocarcinoma of the stomach, colon and lung, including constituents of tobacco smoke. We...... differences. Thus p53 does not seem to be the target of carcinogens acting in the small intestine....

  11. Functional characterization of glutathione S-transferases associated with insecticide resistance in Tetranychus urticae

    NARCIS (Netherlands)

    N. Pavlidi; V. Tseliou; M. Riga; R. Nauen; T. Van Leeuwen; N.E. Labrou; J. Vontas

    2015-01-01

    The two-spotted spider mite Tetranychus urticae is one of the most important agricultural pests world-wide. It is extremely polyphagous and develops resistance to acaricides. The overexpression of several glutathione S-transferases (GSTs) has been associated with insecticide resistance. Here, we fun

  12. Partial hypoxanthine-guanine phosphoribosyl transferase deficiency without elevated urinary hypoxanthine excretion

    NARCIS (Netherlands)

    van Dael, C. M. L.; Pierik, L. J. W. M.; Reijngoud, D. J.; Niezen-Koning, K. E.; van Diggelen, O. P.; van Spronsen, F. J.

    2007-01-01

    Partial hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficiency, also known as the Kelley-Seegmiller syndrome, can give rise to a wide range of neurological symptoms, and renal insufficiency. Biochemically, it is characterized by high uric acid concentrations in blood, high uric acid and

  13. Role of genetic polymorphism of glutathione-s-transferase T1 and microsomal epoxide hydrolase in aflatoxin-associated hepatocellular carcinoma

    NARCIS (Netherlands)

    Tiemersma, E.W.; Omer, R.E.; Bunschoten, A.; Veer, van't P.; Kok, F.J.; Idrsi, M.O.; Kampman, E.

    2001-01-01

    Exposure to aflatoxins is a risk factor for hepatocellular carcinoma (HCC). Aflatoxins occur in peanut butter and are metabolized by genetically polymorphic enzymes such as glutathione-S-transferases encoded by glutathione-S-transferase mu 1 gene (GSTM1) and glutathione-S-transferase theta 1 gene (G

  14. Functional dissection of the bipartite active site of the class I coenzyme A (CoA)-transferase succinyl-CoA:acetate CoA-transferase

    Science.gov (United States)

    Murphy, Jesse; Mullins, Elwood; Kappock, T.

    2016-05-01

    Coenzyme A (CoA)-transferases catalyze the reversible transfer of CoA from acyl-CoA thioesters to free carboxylates. Class I CoA-transferases produce acylglutamyl anhydride intermediates that undergo attack by CoA thiolate on either the internal or external carbonyl carbon atoms, forming distinct tetrahedral intermediates less than 3 Å apart. In this study, crystal structures of succinyl-CoA:acetate CoA-transferase (AarC) from Acetobacter aceti are used to examine how the Asn347 carboxamide stabilizes the internal oxyanion intermediate. A structure of the active mutant AarC-N347A bound to CoA revealed both solvent replacement of the missing contact and displacement of the adjacent Glu294, indicating that Asn347 both polarizes and orients the essential glutamate. AarC was crystallized with the nonhydrolyzable acetyl-CoA (AcCoA) analogue dethiaacetyl-CoA (1a) in an attempt to trap a closed enzyme complex containing a stable analogue of the external oxyanion intermediate. One active site contained an acetylglutamyl anhydride adduct and truncated 1a, an unexpected result hinting at an unprecedented cleavage of the ketone moiety in 1a. Solution studies confirmed that 1a decomposition is accompanied by production of near-stoichiometric acetate, in a process that seems to depend on microbial contamination but not AarC. A crystal structure of AarC bound to the postulated 1a truncation product (2a) showed complete closure of one active site per dimer but no acetylglutamyl anhydride, even with acetate added. These findings suggest that an activated acetyl donor forms during 1a decomposition; a working hypothesis involving ketone oxidation is offered. The ability of 2a to induce full active site closure furthermore suggests that it subverts a system used to impede inappropriate active site closure on unacylated CoA.

  15. Functional dissection of the bipartite active site of the class I coenzyme A (CoA-transferase succinyl-CoA:acetate CoA-transferase

    Directory of Open Access Journals (Sweden)

    Jesse Ray Murphy

    2016-05-01

    Full Text Available Coenzyme A (CoA-transferases catalyze the reversible transfer of CoA from acyl-CoA thioesters to free carboxylates. Class I CoA-transferases produce acylglutamyl anhydride intermediates that undergo attack by CoA thiolate on either the internal or external carbonyl carbon atoms, forming distinct tetrahedral intermediates less than 3 Å apart. In this study, crystal structures of succinyl-CoA:acetate CoA-transferase (AarC from Acetobacter aceti are used to examine how the Asn347 carboxamide stabilizes the internal oxyanion intermediate. A structure of the active mutant AarC-N347A bound to CoA revealed both solvent replacement of the missing contact and displacement of the adjacent Glu294, indicating that Asn347 both polarizes and orients the essential glutamate. AarC was crystallized with the nonhydrolyzable acetyl-CoA (AcCoA analogue dethiaacetyl-CoA (1a in an attempt to trap a closed enzyme complex containing a stable analogue of the external oxyanion intermediate. One active site contained an acetylglutamyl anhydride adduct and truncated 1a, an unexpected result hinting at an unprecedented cleavage of the ketone moiety in 1a. Solution studies confirmed that 1a decomposition is accompanied by production of near-stoichiometric acetate, in a process that seems to depend on microbial contamination but not AarC. A crystal structure of AarC bound to the postulated 1a truncation product (2a showed complete closure of one active site per dimer but no acetylglutamyl anhydride, even with acetate added. These findings suggest that an activated acetyl donor forms during 1a decomposition; a working hypothesis involving ketone oxidation is offered. The ability of 2a to induce full active site closure furthermore suggests that it subverts a system used to impede inappropriate active site closure on unacylated CoA.

  16. In vitro fermentation patterns of rice bran components by human gut microbiota

    Science.gov (United States)

    Rice bran is a rich source of bioactive components that can promote gastrointestinal health. However, bran is removed during polishing. Among those, feruloylated arabinoxylan oligosaccharides (FAXO) and rice bran polyphenolics (RBPP) are hypothesized to have positive impacts on human gut microbiota ...

  17. GalNAc-transferase specificity prediction based on feature selection method.

    Science.gov (United States)

    Lu, Lin; Niu, Bing; Zhao, Jun; Liu, Liang; Lu, Wen-Cong; Liu, Xiao-Jun; Li, Yi-Xue; Cai, Yu-Dong

    2009-02-01

    GalNAc-transferase can catalyze the biosynthesis of O-linked oligosaccharides. The specificity of GalNAc-transferase is composed of nine amino acid residues denoted by R4, R3, R2, R1, R0, R1', R2', R3', R4'. To predict whether the reducing monosaccharide will be covalently linked to the central residue R0(Ser or Thr), a new method based on feature selection has been proposed in our work. 277 nonapeptides from reference [Chou KC. A sequence-coupled vector-projection model for predicting the specificity of GalNAc-transferase. Protein Sci 1995;4:1365-83] are chosen for training set. Each nonapeptide is represented by hundreds of amino acid properties collected by Amino Acid Index database (http://www.genome.jp/aaindex) and transformed into a numeric vector with 4554 features. The Maximum Relevance Minimum Redundancy (mRMR) method combining with Incremental Feature Selection (IFS) and Feature Forward Selection (FFS) are then applied for feature selection. Nearest Neighbor Algorithm (NNA) is used to build prediction models. The optimal model contains 54 features and its correct rate tested by Jackknife cross-validation test reaches 91.34%. Final feature analysis indicates that amino acid residues at position R3' play the most important role in the recognition of GalNAc-transferase specificity, which were confirmed by the experiments [Elhammer AP, Poorman RA, Brown E, Maggiora LL, Hoogerheide JG, Kezdy FJ. The specificity of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase as inferred from a database of in vivo substrates and from the in vitro glycosylation of proteins and peptides. J Biol Chem 1993;268:10029-38; O'Connell BC, Hagen FK, Tabak LA. The influence of flanking sequence on the O-glycosylation of threonine in vitro. J Biol Chem 1992;267:25010-8; Yoshida A, Suzuki M, Ikenaga H, Takeuchi M. Discovery of the shortest sequence motif for high level mucin-type O-glycosylation. J Biol Chem 1997;272:16884-8]. Our method can be used as a tool for predicting O

  18. The pleuromutilin drugs tiamulin and valnemulin bind to the RNA at the peptidyl transferase centre on the ribosome

    DEFF Research Database (Denmark)

    Poulsen, S M; Karlsson, M; Johansson, L B;

    2001-01-01

    centre and have been associated with binding of several antibiotics. Competitive footprinting shows that tiamulin and valnemulin can bind concurrently with the macrolide erythromycin but compete with the macrolide carbomycin, which is a peptidyl transferase inhibitor. We infer from these and previous...... are strong inhibitors of peptidyl transferase and interact with domain V of 23S RNA, giving clear chemical footprints at nucleotides A2058-9, U2506 and U2584-5. Most of these nucleotides are highly conserved phylogenetically and functionally important, and all of them are at or near the peptidyl transferase...

  19. Three-dimensional structure of a Bombyx mori Omega-class glutathione transferase.

    Science.gov (United States)

    Yamamoto, Kohji; Suzuki, Mamoru; Higashiura, Akifumi; Nakagawa, Atsushi

    2013-09-01

    Glutathione transferases (GSTs) are major phase II detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here we report the crystal structure of an Omega-class glutathione transferase of Bombyx mori, bmGSTO, to gain insight into its catalytic mechanism. The structure of bmGSTO complexed with glutathione determined at a resolution of 2.5Å reveals that it exists as a dimer and is structurally similar to Omega-class GSTs with respect to its secondary and tertiary structures. Analysis of a complex between bmGSTO and glutathione showed that bound glutathione was localized to the glutathione-binding site (G-site). Site-directed mutagenesis of bmGSTO mutants indicated that amino acid residues Leu62, Lys65, Lys77, Val78, Glu91 and Ser92 in the G-site contribute to catalytic activity.

  20. Structural characterization of the catalytic site of a Nilaparvata lugens delta-class glutathione transferase.

    Science.gov (United States)

    Yamamoto, Kohji; Higashiura, Akifumi; Hossain, Md Tofazzal; Yamada, Naotaka; Shiotsuki, Takahiro; Nakagawa, Atsushi

    2015-01-15

    Glutathione transferases (GSTs) are a major class of detoxification enzymes that play a central role in the defense against environmental toxicants and oxidative stress. Here, we studied the crystal structure of a delta-class glutathione transferase from Nilaparvata lugens, nlGSTD, to gain insights into its catalytic mechanism. The structure of nlGSTD in complex with glutathione, determined at a resolution of 1.7Å, revealed that it exists as a dimer and its secondary and tertiary structures are similar to those of other delta-class GSTs. Analysis of a complex between nlGSTD and glutathione showed that the bound glutathione was localized to the glutathione-binding site. Site-directed mutagenesis of nlGSTD mutants indicated that amino acid residues Ser11, His52, Glu66, and Phe119 contribute to catalytic activity.

  1. Lectin Domains of Polypeptide GalNAc Transferases Exhibit Glycopeptide Binding Specificity

    DEFF Research Database (Denmark)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G;

    2011-01-01

    UDP-GalNAc:polypeptide a-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection...... of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence...... on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate...

  2. Isolation and Characterization of a Theta Glutathione S-transferase Gene from Panax ginseng Meyer

    OpenAIRE

    Kim, Yu-Jin; Lee, Ok Ran; Lee, Sungyoung; Kim, Kyung-Tack; Yang, Deok-Chun

    2012-01-01

    Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is known about the role of ginseng GSTs. Therefore, this work aimed to provide further information on the G...

  3. Expression of glutathione S-transferases in normal and malignant pancreas: an immunohistochemical study.

    OpenAIRE

    Collier, J D; Bennett, M K; Hall, A.; Cattan, A R; Lendrum, R.; Bassendine, M F

    1994-01-01

    The glutathione S-transferases (GSTs) are a family of detoxification and metabolising enzymes, which have been linked with the susceptibility of tissues to environmental carcinogens and resistance of tumours to chemotherapy. Environmental carcinogens have been implicated in the pathogenesis of pancreatic carcinoma, which is also a tumour characterised by marked chemotherapeutic drug resistance. In this study 26 pancreatic adenocarcinoma and 12 normal pancreatic samples were examined immunohis...

  4. Predicted binding of certain antifilarial compounds with glutathione-S-transferase of human Filariids

    OpenAIRE

    Saeed, Mohd; Baig, Mohd. Hassan; Bajpai, Preeti; Srivastava, Ashwini Kumar; Ahmad, Khurshid; Mustafa, Huma

    2013-01-01

    Glutathione-S-transferase is a major phase-II detoxification enzyme in parasitic helminthes. Previous research highlights the importance of GSTs in the establishment of chronic infections in cytotoxic microenvironments. Filarial nematodes depend on these detoxification enzymes for their survival in the host. GST plays an important role in filariasis and other diseases. GST from W.bancrofti and B.malayi are very much different from human GST. This structural difference makes GST potential chem...

  5. Glutathione S-Transferase Polymorphisms, Passive Smoking, Obesity, and Heart Rate Variability in Nonsmokers

    OpenAIRE

    Probst-Hensch, Nicole M.; Imboden, Medea; Dietrich, Denise Felber; Barthélemy, Jean-Claude; Ackermann-Liebrich, Ursula; Berger, Wolfgang; Gaspoz, Jean-Michel; Schwartz, Joel David

    2008-01-01

    Background: Disturbances of heart rate variability (HRV) may represent one pathway by which second-hand smoke (SHS) and air pollutants affect cardiovascular morbidity and mortality. The mechanisms are poorly understood. Objectives: We investigated the hypothesis that oxidative stress alters cardiac autonomic control. We studied the association of polymorphisms in oxidant-scavenging glutathione S-transferase (GST) genes and their interactions with SHS and obesity with HRV. Methods: A total of ...

  6. Structural insight into the active site of a Bombyx mori unclassified glutathione transferase.

    Science.gov (United States)

    Hossain, Md Tofazzal; Yamamoto, Kohji

    2015-01-01

    Glutathione transferases (GSTs) are major detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here, we identify amino acid residues of an unclassified GST from Bombyx mori, bmGSTu-interacting glutathione (GSH). Site-directed mutagenesis of bmGSTu mutants indicated that amino acid residues Asp103, Ser162, and Ser166 contribute to catalytic activity.

  7. Summarize of Glutathione S-transferases%谷胱甘肽S-转移酶综述

    Institute of Scientific and Technical Information of China (English)

    张飚; 李永清; 高轩

    2006-01-01

    谷胱甘肽S-转移酶(glutathioneS-transferases,GSTs)是由多个基因编码、具有多种功能的超基因家族酶,是多种生物体内的主要解毒系统.本文综述了GSTs的分型、结构等方面的研究进展.

  8. Methionine sulfoxide reductase regulates brain catechol-O-methyl transferase activity

    OpenAIRE

    Moskovitz, Jackob; Walss-Bass, Consuelo; Cruz, Dianne A.; Thompson, Peter M.; Bortolato, Marco

    2014-01-01

    Catechol-O-methyl transferase (COMT) plays a key role in the degradation of brain dopamine (DA). Specifically, low COMT activity results in higher DA levels in the prefrontal cortex (PFC), thereby reducing the vulnerability for attentional and cognitive deficits in both psychotic and healthy individuals. COMT activity is markedly reduced by a non-synonymous SNP that generates a valine-to-methionine substitution on the residue 108/158, by means of as-yet incompletely understood posttranslation...

  9. Expression Profiling of Selected Glutathione Transferase Genes in Zea mays (L.) Seedlings Infested with Cereal Aphids

    OpenAIRE

    Hubert Sytykiewicz; Grzegorz Chrzanowski; Paweł Czerniewicz; Iwona Sprawka; Iwona Łukasik; Sylwia Goławska; Cezary Sempruch

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2 •−) in infested Z. mays plants was ...

  10. Frequency of Galactose-1-phosphate Uridyl Transferase Gene Mutations in Healthy Population of Croatia

    OpenAIRE

    Barišić, Karmela; Rumora, Lada; Grdić, Marija; JURETIĆ, DUBRAVKA

    2008-01-01

    Galactosemia is a human disease caused by deficient activity of each one of the three enzymes involved in galactose metabolism, galactokinase (GALK), galactose-1-phosphate uridyl transferase (GALT) and UDP-galactose-4-epimerase (GALE). Absence or deficiency of GALT activity results in classical galactosemia. This disorder exhibits allelic heterogeneity in different populations and ethnic groups. The aim of this study was to search for galactosemia mutations Q188R, N314D, and K285N in healthy ...

  11. Modeling analysis of GST (glutathione-S-transferases) from Wuchereria bancrofti and Brugia malayi

    OpenAIRE

    Bhargavi, Rayavarapu; Vishwakarma, Siddharth; Murty, Upadhyayula Suryanarayana

    2005-01-01

    GST (glutathione S-transferases) are a family of detoxification enzymes that catalyze the conjugation of reduced GSH (glutathione) to xenobiotic (endogenous electrophilic) compounds. GST from Wb (Wuchereria bancrofti) and Bm (Brugia malayi) are significantly different from human GST in sequence and structure. Thus, Wb-GST and Bm-GST are potential chemotherapeutic targets for anti-filarial treatment. Comparison of modeled Wb and Bm GST with human GST show structural difference between them. An...

  12. Nourseothricin N-acetyl transferase: a positive selection marker for mammalian cells.

    Directory of Open Access Journals (Sweden)

    Bose S Kochupurakkal

    Full Text Available Development of Nourseothricin N-acetyl transferase (NAT as a selection marker for mammalian cells is described. Mammalian cells are acutely susceptible to Nourseothricin, similar to the widely used drug Puromycin, and NAT allows for quick and robust selection of transfected/transduced cells in the presence of Nourseothricin. NAT is compatible with other selection markers puromycin, hygromycin, neomycin, blasticidin, and is a valuable addition to the repertoire of mammalian selection markers.

  13. Genetic polymorphism for glutathione-S-transferase mu in asbestos cement workers.

    OpenAIRE

    Jakobsson, K; Rannug, A.; Alexandrie, A K; Rylander, L; Albin, M; Hagmar, L

    1994-01-01

    OBJECTIVE--To investigate whether a lack of glutathione-S-transferase mu (GSTM1) activity was related to an increased risk for adverse outcome after asbestos exposure. METHODS--A study was made of 78 male former asbestos cement workers, with retrospective cohort data on exposure, radiographical findings, and lung function. Venous blood samples were obtained for the analysis of GSTM1 polymorphism by the polymerase chain reaction technique. Chest x ray films were classified according to the Int...

  14. Exploiting the Substrate Promiscuity of Hydroxycinnamoyl-CoA:Shikimate Hydroxycinnamoyl Transferase to Reduce Lignin

    OpenAIRE

    Eudes, Aymerick; Pereira, Jose H.; Yogiswara, Sasha; Wang, George; Teixeira Benites, Veronica; Baidoo, Edward E.K.; Lee, Taek Soon; Adams, Paul D; Keasling, Jay D.; Loqué, Dominique

    2016-01-01

    Lignin poses a major challenge in the processing of plant biomass for agro-industrial applications. For bioengineering purposes, there is a pressing interest in identifying and characterizing the enzymes responsible for the biosynthesis of lignin. Hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase (HCT; EC 2.3.1.133) is a key metabolic entry point for the synthesis of the most important lignin monomers: coniferyl and sinapyl alcohols. In this study, we investigated the substrate prom...

  15. Wild-type HTT modulates the enzymatic activity of the neuronal palmitoyl transferase HIP14

    OpenAIRE

    Huang, Kun; Shaun S Sanders; Kang, Rujun; Carroll, Jeffrey B; Sutton, Liza; Wan, Junmei; Singaraja, Roshni; Young, Fiona B.; Liu, Lili; El-Husseini, Alaa; Davis, Nicholas G.; Hayden, Michael R.

    2011-01-01

    Huntington disease (HD) is caused by polyglutamine expansion in the huntingtin (HTT) protein. Huntingtin-interacting protein 14 (HIP14), one of 23 DHHC domain-containing palmitoyl acyl transferases (PATs), binds to HTT and robustly palmitoylates HTT at cysteine 214. Mutant HTT exhibits reduced palmitoylation and interaction with HIP14, contributing to the neuronal dysfunction associated with HD. In this study, we confirmed that, among 23 DHHC PATs, HIP14 and its homolog DHHC-13 (HIP14L) are t...

  16. Functional and physical interaction between the histone methyl transferase Suv39H1 and histone deacetylases

    OpenAIRE

    Vaute, Olivier; Nicolas, Estelle; Vandel, Laurence; Trouche, Didier

    2002-01-01

    The histone methyl transferase Suv39H1 is involved in silencing by pericentric heterochromatin. It specifically methylates K9 of histone H3, thereby creating a high affinity binding site for HP1 proteins. We and others have shown recently that it is also involved in transcriptional repression by the retinoblastoma protein Rb. Strikingly, both HP1 localisation and repression by Rb also require, at least in part, histone deacetylases. We found here that repression of a heterologous promoter by ...

  17. Proteomic and Immunochemical Characterization of Glutathione Transferase as a New Allergen of the Nematode Ascaris lumbricoides

    OpenAIRE

    Nathalie Acevedo; Jens Mohr; Josefina Zakzuk; Martin Samonig; Peter Briza; Anja Erler; Anna Pomés; Huber, Christian G.; Fatima Ferreira; Luis Caraballo

    2013-01-01

    Helminth infections and allergy have evolutionary and clinical links. Infection with the nematode Ascaris lumbricoides induces IgE against several molecules including invertebrate pan-allergens. These antibodies influence the pathogenesis and diagnosis of allergy; therefore, studying parasitic and non-parasitic allergens is essential to understand both helminth immunity and allergy. Glutathione transferases (GSTs) from cockroach and house dust mites are clinically relevant allergens and compa...

  18. Role of glutathione, glutathione transferase, and glutaredoxin in regulation of redox-dependent processes.

    Science.gov (United States)

    Kalinina, E V; Chernov, N N; Novichkova, M D

    2014-12-01

    Over the last decade fundamentally new features have been revealed for the participation of glutathione and glutathione-dependent enzymes (glutathione transferase and glutaredoxin) in cell proliferation, apoptosis, protein folding, and cell signaling. Reduced glutathione (GSH) plays an important role in maintaining cellular redox status by participating in thiol-disulfide exchange, which regulates a number of cell functions including gene expression and the activity of individual enzymes and enzyme systems. Maintaining optimum GSH/GSSG ratio is essential to cell viability. Decrease in the ratio can serve as an indicator of damage to the cell redox status and of changes in redox-dependent gene regulation. Disturbance of intracellular GSH balance is observed in a number of pathologies including cancer. Consequences of inappropriate GSH/GSSG ratio include significant changes in the mechanism of cellular redox-dependent signaling controlled both nonenzymatically and enzymatically with the participation of isoforms of glutathione transferase and glutaredoxin. This review summarizes recent data on the role of glutathione, glutathione transferase, and glutaredoxin in the regulation of cellular redox-dependent processes.

  19. Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

    Directory of Open Access Journals (Sweden)

    Chin-Soon Chee

    2014-01-01

    Full Text Available Glutathione transferases (GST were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW of 23 kDa. 2-dimensional (2-D gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5 and GST2 (pI 6.2 with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase and F0KKB0 (glutathione S-transferase III of Acinetobacter calcoaceticus strain PHEA-2, respectively.

  20. Erythromycin binding is reduced in ribosomes with conformational alterations in the 23 S rRNA peptidyl transferase loop

    DEFF Research Database (Denmark)

    Douthwaite, S; Aagaard, C

    1993-01-01

    that are induced by mutations in the peptidyl transferase loop, and to determine how these changes affect drug interaction. Mutations at positions 2057 (G-->A) and 2058 (A-->G, or -->U), all of which confer drug resistance, induce a more open conformation in the peptidyl transferase loop. Erythromycin still......The antibiotic erythromycin inhibits protein synthesis by binding to the 50 S ribosomal subunit, where the drug interacts with the unpaired bases 2058A and 2059A in the peptidyl transferase loop of 23 S rRNA. We used a chemical modification approach to analyse conformational changes...... previously been shown to alter drug tolerances, gave no detectable effects on the structure of the peptidyl transferase loop or on erythromycin binding. Dual mutations at positions 2032 and 2058, however, induce a marked change in the rRNA conformation with opening of the phylogenetically conserved base...

  1. A study of the prognostic role of serum fucose and fucosyl transferase in cancer of the uterine cervix.

    OpenAIRE

    Sen, Urmi; Guha,Subhas; Chowdhury, J Roy

    1985-01-01

    Serum fucose levels and fucosyl transferase activities have been designated as nonspecific markers of malignancy, and play an important role in the diagnosis of different types of malignancies. In the present study, attempts were made to determine the prognostic significance of these markers in patients with cancer of the uterine cervix after therapy. It was found that both serum fucose and fucosyl transferase, which were elevated in untreated patients declined significantly in patients respo...

  2. Preparation of feruloyl esterase and application in feed of broiler%阿魏酸酯酶的制备及在肉鸡饲料中的应用

    Institute of Scientific and Technical Information of China (English)

    杨道秀; 许文江; 王林林; 蔡婀娜; 李夏兰

    2013-01-01

    为了降低饲料中非淀粉多糖质量抗营养因子,提高肉鸡对饲料养分的利用,本文研究了固态发酵阿魏酸酯酶的工艺及其对饲料养分利用率的影响。结果表明:在麦麸与麦糟质量比为2∶8、蛋白胨与酵母粉质量比为2∶4、含水量为40%、接种量为10%、培养时间为6天、培养温度为33℃条件下,阿魏酸酯酶的酶活达到了29.49 U/g,较未优化前提高了5.11倍。将浓缩后的酶液与溢多酶AF831添加入肉鸡饲料中,发现添加溢多酶及阿魏酸酯酶可以提高干物质、粗蛋白、粗灰分、酸性洗涤纤维等利用率,但作用不明显,对中性洗涤纤维改善效果极显著(P<0.01)。%To reduce non-starch polysaccharides anti-nutritional factor in feed and promote intake of nutrient,the solid-state fermentation technology of feruloyl esterase (FAE) and the influence on nutrient utilization rate were studied. Under optimized conditions of 2∶8 of the ratio for wheat bran and brewers’ spent grain (BSG),2∶4 of the ratio for peptone and yeast,40%of water content,10%of inoculum,6 days of incubation and 33 ℃ of incubation temperature,the activity of FAE was improved to five times compared to unoptimized conditions and the maximum activity was 29.49 U/g. The combination of FAE and Yiduoli enzyme was mixed in feed for broiler. FAE and Yiduoli enzyme could improve the utilization of dry matter,crude protein,crude ash,acidic detergent fiber,but the improvement was limited. The utilization of neutral detergent fiber increased markedly (P<0.01).

  3. Inherited glutathione-S-transferase deficiency is a risk factor for pulmonary asbestosis.

    Science.gov (United States)

    Smith, C M; Kelsey, K T; Wiencke, J K; Leyden, K; Levin, S; Christiani, D C

    1994-09-01

    Pulmonary diseases attributable to asbestos exposure constitute a significant public health burden, yet few studies have investigated potential genetic determinants of susceptibility to asbestos-related diseases. The glutathione-S-transferases are a family of conjugating enzymes that both catalyze the detoxification of a variety of potentially cytotoxic electrophilic agents and act in the generation of sulfadipeptide leukotriene inflammatory mediators. The gene encoding glutathione-S-transferase class mu (GSTM-1) is polymorphic; approximately 50% of Caucasian individuals have a homozygous deletion of this gene and do not produce functional enzyme. Glutathione-S-transferase mu (GST-mu) deficiency has been previously reported to be associated with smoking-induced lung cancer. We conducted a cross-sectional study to examine the prevalence of the homozygous deletion for the GSTM-1 gene in members of the carpentry trade occupationally exposed to asbestos. Members of the United Brotherhood of Carpenters and Joiners of America attending their 1991 National Union conference were invited to participate. Each participant was offered a chest X-ray and was asked to complete a comprehensive questionnaire and have their blood drawn. All radiographs were assessed for the presence of pneumoconiosis in a blinded fashion by a National Institute for Occupational Safety and Health-certified International Labor Office "B" reader. Individual GSTM-1 status was determined using polymerase chain reaction methods. Six hundred fifty-eight workers were studied. Of these, 80 (12.2%) had X-ray abnormalities associated with asbestos exposure. Individuals genetically deficient in GST-mu were significantly more likely to have radiographic evidence of nonmalignant asbestos-related disease than those who were not deficient (chi 2 = 5.0; P < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Cefadroxil potency as cancer co-therapy candidate by glutathione s-transferase mechanism

    OpenAIRE

    Tri Yuliani; Sudibyo Martono; Sansan Sukamdani Tjipto; Muhammad Yusuf Putroutomo; Irwan Desyanto Raharjo Indartono

    2013-01-01

    Background: Glutathione S-transferases (GSTs) havean important role in the detoxification of electrophiles,such as some anticancer drugs. Compounds with phenolicand/or α,b-unsaturated carbonyl group have been knownas GSTs inhibitor in vitro. Cefadroxil in vitro decreasedGST-Pi activity but not GSTs in rat kidney cytosol.GST inhibitor in a specific organ and of a specific classis needed for safety in cancer chemotherapy. The studyaims to observe the effect of cefadroxil on GSTs in vivoin rat k...

  5. Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

    OpenAIRE

    Chin-Soon Chee; Irene Kit-Ping Tan; Zazali Alias

    2014-01-01

    Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was r...

  6. Glutathione S-transferase pi localizes in mitochondria and protects against oxidative stress.

    OpenAIRE

    Goto, Shinji; Kawakatsu, Miho; Izumi, Shin-ichi; Urata, Yoshishige; Kageyama, Kan; Ihara, Yoshito; Koji, Takehiko; Kondo, Takahito

    2009-01-01

    Glutathione S-transferases (GSTs) are multifunctional enzymes involved in the protection of cellular components against anti-cancer drugs or peroxidative stress. Previously we found that GST pi, an isoform of the GSTs, is transported into the nucleus. In the present study, we found that GST pi is present in mitochondria as well as in the cytosol and nucleus in mammalian cell lines. A construct comprising the 84 amino acid residues in the amino-terminal region of GST pi and green fluorescent p...

  7. Cloning, expression and analysis of the olfactory glutathione S-transferases in coho salmon

    OpenAIRE

    Espinoza, Herbert M.; Shireman, Laura M.; McClain, Valerie; Atkins, William; Gallagher, Evan P.

    2012-01-01

    The glutathione S-transferases (GSTs) provide cellular protection by detoxifying xenobiotics, maintaining redox status, and modulating secondary messengers, all of which are critical to maintaining olfaction in salmonids. Here, we characterized the major coho salmon olfactory GSTs (OlfGSTs), namely omega, pi, and rho subclasses. OlfGST omega contained an open reading frame of 720 bp and encoded a protein of 239 amino acids. OlfGST pi and OlfGST rho contained open reading frames of 727 and 681...

  8. Physicochemical consequences of the perdeuteriation of glutathione S-transferase from S. japonicum

    OpenAIRE

    Brockwell, David; Yu, Lu; Cooper, Serena; Mccleland, Steven; Cooper, Alan; Attwood, David; Gaskell, Simon J.; Barber, Jill

    2001-01-01

    Glutathione S-transferase (GST) from Schistosoma japonicum has been prepared in both normal protiated (pGST) and fully deuteriated (dGST) form by recombinant DNA technology. Electrospray mass spectrometry showed that the level of deuteriation in dGST was 96% and was homogeneous across the sample. This result is attributed to the use of a deuterium-tolerant host Escherichia coli strain in the preparation of the protein. 10 heteroatom-bound deuteriums (in addition to the carbon-bound deuteriums...

  9. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

    Science.gov (United States)

    Hossain, M D Tofazzal; Yamada, Naotaka; Yamamoto, Kohji

    2014-01-01

    The glutathione transferase (GST) superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT) catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy)-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  10. Mechanism of activation of mouse liver microsomal glutations S—transferase by paracetamol treatment

    Institute of Scientific and Technical Information of China (English)

    ZhenY; LouYJ

    2002-01-01

    Microsomal glutathion S-transferase(mGST) is one of the important detoxifcation enzymes in vivo,its modifying activation by drugs has been paid more attention to in pertinent field recently.This study was to explore the influence of paracetamol(Par) on mGST and its possible mechanism in vivo,and to further reveal the biological significance.Par is metabolized to N-acetyl-p-benzoquinone imine(NAPQI) by CYP2E1 and mGST is activated by sulfhydryl modification.

  11. Fucosylation of xyloglucan: localization of the transferase in dictyosomes of pea stem cells

    International Nuclear Information System (INIS)

    Microsomal membranes from elongating regions of etiolated Pisum sativum stems were separated by rate-zonal centrifugation on Renografin gradients. The transfer of labeled fucose and xylose from GDP-[14C] fucose and UDP-[14C]xylose to xyloglucan occurred mainly in dictyosome-enriched fractions. No transferase activity was detected in secretory vesicle fractions. Pulse-chase experiments using pea stem slices incubated with [3H]fucose suggest that xyloglucan chains are fucosylated and their structure completed within the dictyosomes, before being transported to the cell wall by secretory vesicles

  12. Generation of Active Bovine Terminal Deoxynucleotidyl Transferase (TdT in E.coli

    Directory of Open Access Journals (Sweden)

    Wee Liang Kuan

    2010-08-01

    Full Text Available A synthetic gene encoding bovine terminal deoxynucleotidyl transferase (TdT was generated, cloned into an expression vector and expressed in E.coli. The effects of altering culture and induction conditions on the nature of recombinant protein production were investigated. This led to the expression of active recombinant bovine TdT in E.coli. After purification and characterisation, the activity of the enzyme was assessed in a biological assay for apoptosis. The process described in this report enables the economical production of TdT for high throughput applications.

  13. Micronuclei rate and hypoxanthine phosphoribosyl transferase mutation in radon-exposed rats

    Institute of Scientific and Technical Information of China (English)

    Fengmei Cui; Saijun Fan; Mingjiang Hu; Jihua Nie; Hongmei Li; Jian Tong

    2008-01-01

    The genetic changes in rats with radon exposure were studied by the micronucleus technology and detection of hypoxanthine phosphoribosyl transferase (hprt) mutations.The rate of the micronuclei in peripheral blood lymphocytes and tracheal-bronchial epithelial cells in the radon-inhaled rats was higher than that of the controls (P < 0.05).A similar result was obtained from the hprt assay,which showed a higher mutation frequency in radon-exposed rats.Our results suggested that micronuclei rate and hprt deficiency could be used as biomarkers for the genetic changes with radon exposure.

  14. UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase. Identification and separation of two distinct transferase activities

    DEFF Research Database (Denmark)

    Sørensen, T; White, T; Wandall, H H;

    1995-01-01

    Using a defined acceptor substrate peptide as an affinity chromatography ligand we have developed a purification scheme for a unique human polypeptide, UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) (White, T., Bennett, E.P., Takio, K., Sørensen, T., Bonding, N., an....... The identification of acceptor peptides that can be used to discriminate GalNAc-transferase activities is an important step toward understanding the molecular basis of GalNAc O-linked glycosylation in cells and organs and in pathological conditions.......Using a defined acceptor substrate peptide as an affinity chromatography ligand we have developed a purification scheme for a unique human polypeptide, UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) (White, T., Bennett, E.P., Takio, K., Sørensen, T., Bonding, N......., and Clausen, H. (1995) J. Biol. Chem. 270, 24156-24165). Here we report detailed studies of the acceptor substrate specificity of GalNAc-transferase purified by this scheme as well as the Gal-NAc-transferase activity, which, upon repeated affinity chromatography, evaded purification by this affinity ligand...

  15. Rescue of Drosophila Melanogaster l(2)35Aa lethality is only mediated by polypeptide GalNAc-transferase pgant35A, but not by the evolutionary conserved human ortholog GalNAc-transferase-T11

    DEFF Research Database (Denmark)

    Bennett, Eric P; Chen, Ya-Wen; Schwientek, Tilo;

    2010-01-01

    conserved family of genes encoding polypeptide GalNAc-transferases. Phylogenetic and functional analyses have proposed that subfamilies of orthologous GalNAc-transferase genes are conserved in species, suggesting that they serve distinct functions in vivo. Based on sequence alignments, pgant35A and human......)35Aa lethality. By use of genetic "domain swapping" experiments we demonstrate, that lack of rescue was not caused by inappropriate sub-cellular targeting of functionally active GalNAc-T11. Collectively our results show, that fly embryogenesis specifically requires functional pgant35A......, and that the presence of this gene product during fly embryogenesis is functionally distinct from other Drosophila GalNAc-transferase isoforms and from the proposed human ortholog GALNT11....

  16. Selective inhibitors of glutathione transferase P1 with trioxane structure as anticancer agents.

    Science.gov (United States)

    Bräutigam, Maria; Teusch, Nicole; Schenk, Tobias; Sheikh, Miriam; Aricioglu, Rocky Z; Borowski, Swantje H; Neudörfl, Jörg-Martin; Baumann, Ulrich; Griesbeck, Axel G; Pietsch, Markus

    2015-04-01

    The response to chemotherapy in cancer patients is frequently compromised by drug resistance. Although chemoresistance is a multifactorial phenomenon, many studies have demonstrated that altered drug metabolism through the expression of phase II conjugating enzymes, including glutathione transferases (GSTs), in tumor cells can be directly correlated with resistance against a wide range of marketed anticancer drugs. In particular, overexpression of glutathione transferase P1 (GSTP1) appears to be a factor for poor prognosis during cancer therapy. Former and ongoing clinical trials have confirmed GSTP1 inhibition as a principle for antitumor therapy. A new series of 1,2,4-trioxane GSTP1 inhibitors were designed via a type II photooxygenation route of allylic alcohols followed by acid-catalyzed peroxyacetalization with aldehydes. A set of novel inhibitors exhibit low micromolar to high nanomolar inhibition of GSTP1, revealing preliminary SAR for further lead optimization. Importantly, high selectivity over another two human GST classes (GSTA1 and GSTM2) has been achieved. The trioxane GSTP1 inhibitors may therefore serve as a basis for the development of novel drug candidates in overcoming chemoresistance.

  17. Evolutionary divergence of Ure2pA glutathione transferases in wood degrading fungi.

    Science.gov (United States)

    Roret, Thomas; Thuillier, Anne; Favier, Frédérique; Gelhaye, Eric; Didierjean, Claude; Morel-Rouhier, Mélanie

    2015-10-01

    The intracellular systems of detoxification are crucial for the survival of wood degrading fungi. Within these systems, glutathione transferases could play a major role since this family of enzymes is specifically extended in lignolytic fungi. In particular the Ure2p class represents one third of the total GST number in Phanerochaete chrysosporium. These proteins have been phylogenetically split into two subclasses called Ure2pA and Ure2pB. Ure2pB can be classified as Nu GSTs because of shared structural and functional features with previously characterized bacterial isoforms. Ure2pA can rather be qualified as Nu-like GSTs since they exhibit a number of differences. Ure2pA possess a classical transferase activity, a more divergent catalytic site and a higher structural flexibility for some of them, compared to Nu GSTs. The characterization of four members of this Ure2pA subclass (PcUre2pA4, PcUre2pA5, PcUre2pA6 and PcUre2pA8) revealed specific functional and structural features, suggesting that these enzymes have rapidly evolved and differentiated, probably to adapt to the complex chemical environment associated with wood decomposition.

  18. Substrate profiling of glutathione S-transferase with engineered enzymes and matched glutathione analogues.

    Science.gov (United States)

    Feng, Shan; Zhang, Lei; Adilijiang, Gulishana; Liu, Jieyuan; Luo, Minkui; Deng, Haiteng

    2014-07-01

    The identification of specific substrates of glutathione S-transferases (GSTs) is important for understanding drug metabolism. A method termed bioorthogonal identification of GST substrates (BIGS) was developed, in which a reduced glutathione (GSH) analogue was developed for recognition by a rationally engineered GST to label the substrates of the corresponding native GST. A K44G-W40A-R41A mutant (GST-KWR) of the mu-class glutathione S-transferases GSTM1 was shown to be active with a clickable GSH analogue (GSH-R1) as the cosubstrate. The GSH-R1 conjugation products can react with an azido-based biotin probe for ready enrichment and MS identification. Proof-of-principle studies were carried to detect the products of GSH-R1 conjugation to 1-chloro-2,4-dinitrobenzene (CDNB) and dopamine quinone. The BIGS technology was then used to identify GSTM1 substrates in the Chinese herbal medicine Ganmaocongji.

  19. Binding properties of ferrocene-glutathione conjugates as inhibitors and sensors for glutathione S-transferases.

    Science.gov (United States)

    Martos-Maldonado, Manuel C; Casas-Solvas, Juan M; Téllez-Sanz, Ramiro; Mesa-Valle, Concepción; Quesada-Soriano, Indalecio; García-Maroto, Federico; Vargas-Berenguel, Antonio; García-Fuentes, Luís

    2012-02-01

    The binding properties of two electroactive glutathione-ferrocene conjugates that consist in glutathione attached to one or both of the cyclopentadienyl rings of ferrocene (GSFc and GSFcSG), to Schistosoma japonica glutathione S-transferase (SjGST) were studied by spectroscopy fluorescence, isothermal titration calorimetry (ITC) and differential pulse voltammetry (DPV). Such ferrocene conjugates resulted to be competitive inhibitors of glutathione S-transferase with an increased binding affinity relative to the natural substrate glutathione (GSH). We found that the conjugate having two glutathione units (GSFcSG) exhibits an affinity for SjGST approximately two orders of magnitude higher than GSH. Furthermore, it shows negative cooperativity with the affinity for the second binding site two orders of magnitude lower than that for the first one. We propose that the reason for such negative cooperativity is steric since, i) the obtained thermodynamic parameters do not indicate profound conformational changes upon GSFcSG binding and ii) docking studies have shown that, when bound, part of the first bound ligand invades the second site due to its large size. In addition, voltammetric measurements show a strong decrease of the peak current upon binding of ferrocene-glutathione conjugates to SjGST and provide very similar K values than those obtained by ITC. Moreover, the sensing ability, expressed by the sensitivity parameter shows that GSFcSG is much more sensitive than GSFc, for the detection of SjGST.

  20. Catalytic and structural diversity of the fluazifop-inducible glutathione transferases from Phaseolus vulgaris.

    Science.gov (United States)

    Chronopoulou, Evangelia; Madesis, Panagiotis; Asimakopoulou, Basiliki; Platis, Dimitrios; Tsaftaris, Athanasios; Labrou, Nikolaos E

    2012-06-01

    Plant glutathione transferases (GSTs) comprise a large family of inducible enzymes that play important roles in stress tolerance and herbicide detoxification. Treatment of Phaseolus vulgaris leaves with the aryloxyphenoxypropionic herbicide fluazifop-p-butyl resulted in induction of GST activities. Three inducible GST isoenzymes were identified and separated by affinity chromatography. Their full-length cDNAs with complete open reading frame were isolated using RACE-RT and information from N-terminal amino acid sequences. Analysis of the cDNA clones showed that the deduced amino acid sequences share high homology with GSTs that belong to phi and tau classes. The three isoenzymes were expressed in E. coli and their substrate specificity was determined towards 20 different substrates. The results showed that the fluazifop-inducible glutathione transferases from P. vulgaris (PvGSTs) catalyze a broad range of reactions and exhibit quite varied substrate specificity. Molecular modeling and structural analysis was used to identify key structural characteristics and to provide insights into the substrate specificity and the catalytic mechanism of these enzymes. These results provide new insights into catalytic and structural diversity of GSTs and the detoxifying mechanism used by P. vulgaris.

  1. Indication for joint replacement and glutathione s-transferases M1 and T1 genotypes.

    Science.gov (United States)

    Klein, Torsten; Selinski, Silvia; Blaszkewicz, Meinolf; Hengstler, Jan G; Golka, Klaus

    2012-01-01

    In most patients with osteoarthritis (OA), therapy-resistant pain is the indication for hip or knee replacement. Glutathione S-transferases, particularly glutathione S-transferase M1 (GSTM1), are involved in metabolism of highly reactive metabolites that may be generated by inflammatory processes. In total, 148 patients with indication for hip or knee replacement and 129 patients of the same hospital without indication for joint replacement were genotyped for GSTM1 and GSTT1 and interviewed by a newly developed questionnaire for occupational and nonoccupational risk factors of hip and/or knee osteoarthritis. Mean age was 70.9 yr in OA cases and 67.4 yr in controls. The frequency of GSTM1 negative in the OA case group was (45%) in the lower range compared to values in Caucasian general population (approximately 50%), whereas the frequency in the controls was normal (51%). The frequency of GSTT1 negative genotype in OA cases and controls was normal. The normal distribution of the GSTM1 negative genotype in patients with indication for hip or knee replacement indicates that the role GSTM1 in these patients is different from that in other aseptic inflammatory diseases such as ozone-related inflammatory reactions of the respiratory tract.

  2. Miners compensated for pneumoconiosis and glutathione s-transferases M1 and T1 genotypes.

    Science.gov (United States)

    Zimmermann, Anna; Ebbinghaus, Rainer; Prager, Hans-Martin; Blaszkewicz, Meinolf; Hengstler, Jan G; Golka, Klaus

    2012-01-01

    Chronic inhalation of quartz-containing dust produces reversible inflammatory changes in lungs resulting in irreversible fibrotic changes termed pneumoconiosis. Due to the inflammatory process in the lungs, highly reactive substances are released that may be detoxified by glutathione S-transferases. Therefore, 90 hard coal miners with pneumoconiosis as a recognized occupational disease (in Germany: Berufskrankheit BK 4101) were genotyped for glutathione S-transferases M1 (GSTM1) and T1 (GSTT1) according to standard methods. Furthermore, occupational exposure and smoking habits were assessed by questionnaire. Changes in a chest x-ray were classified according to ILO classification 2000. Of the investigated hard coal miners 43% were GSTM1 negative whereas 57% were GSTM1 positive. The arithmetic mean of the age at time of investigation was 74.2 yr (range: 42-87 yr). Seventy-four percent of the hard coal miners reported being ever smokers, while 26% denied smoking. All hard coal miners provided pneumoconiosis-related changes in the chest x-ray. The observed frequency of GSTM1 negative hard coal miners was not different from frequencies reported for general Caucasian populations and in agreement with findings reported for Chinese coal miners. In contrast, in a former study, 16 of 19 German hard coal miners (84%) with urinary bladder cancer displayed a GSTM1 negative genotype. The outcome of this study provides evidence that severely occupationally exposed Caucasian hard coal miners do not present an elevated level of GSTM1 negative individuals.

  3. Characterisation of the Candida albicans Phosphopantetheinyl Transferase Ppt2 as a Potential Antifungal Drug Target.

    Directory of Open Access Journals (Sweden)

    Katharine S Dobb

    Full Text Available Antifungal drugs acting via new mechanisms of action are urgently needed to combat the increasing numbers of severe fungal infections caused by pathogens such as Candida albicans. The phosphopantetheinyl transferase of Aspergillus fumigatus, encoded by the essential gene pptB, has previously been identified as a potential antifungal target. This study investigated the function of its orthologue in C. albicans, PPT2/C1_09480W by placing one allele under the control of the regulatable MET3 promoter, and deleting the remaining allele. The phenotypes of this conditional null mutant showed that, as in A. fumigatus, the gene PPT2 is essential for growth in C. albicans, thus fulfilling one aspect of an efficient antifungal target. The catalytic activity of Ppt2 as a phosphopantetheinyl transferase and the acyl carrier protein Acp1 as a substrate were demonstrated in a fluorescence transfer assay, using recombinant Ppt2 and Acp1 produced and purified from E.coli. A fluorescence polarisation assay amenable to high-throughput screening was also developed. Therefore we have identified Ppt2 as a broad-spectrum novel antifungal target and developed tools to identify inhibitors as potentially new antifungal compounds.

  4. Lectin domains of polypeptide GalNAc transferases exhibit glycopeptide binding specificity.

    Science.gov (United States)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G; Meldal, Morten; Holmér, Andreas P; Blixt, Ola; Cló, Emiliano; Levery, Steven B; Clausen, Henrik; Wandall, Hans H

    2011-09-16

    UDP-GalNAc:polypeptide α-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence specificity, whereas the primary function of the lectin domain is to increase affinity to previously glycosylated substrates. Whether the lectin domain also has peptide sequence selectivity has remained unclear. Using a glycopeptide array with a library of synthetic and recombinant glycopeptides based on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate an additional level of complexity in the initiation step of O-glycosylation by GalNAc-Ts.

  5. High yield production of myristoylated Arf6 small GTPase by recombinant N-myristoyl transferase

    Science.gov (United States)

    Padovani, Dominique; Zeghouf, Mahel; Traverso, José A.; Giglione, Carmela; Cherfils, Jacqueline

    2013-01-01

    Small GTP-binding proteins of the Arf family (Arf GTPases) interact with multiple cellular partners and with membranes to regulate intracellular traffic and organelle structure. Understanding the underlying molecular mechanisms requires in vitro biochemical assays to test for regulations and functions. Such assays should use proteins in their cellular form, which carry a myristoyl lipid attached in N-terminus. N-myristoylation of recombinant Arf GTPases can be achieved by co-expression in E. coli with a eukaryotic N-myristoyl transferase. However, purifying myristoylated Arf GTPases is difficult and has a poor overall yield. Here we show that human Arf6 can be N-myristoylated in vitro by recombinant N-myristoyl transferases from different eukaryotic species. The catalytic efficiency depended strongly on the guanine nucleotide state and was highest for Arf6-GTP. Large-scale production of highly pure N-myristoylated Arf6 could be achieved, which was fully functional for liposome-binding and EFA6-stimulated nucleotide exchange assays. This establishes in vitro myristoylation as a novel and simple method that could be used to produce other myristoylated Arf and Arf-like GTPases for biochemical assays. PMID:23319116

  6. Crystallization and preliminary X-ray analysis of glutathione transferases from cyanobacteria

    International Nuclear Information System (INIS)

    Glutathione S-transferases (GSTs) are a group of detoxifying enzymes that are found in animals, plants and microorganisms. Here, the crystallizations of two cyanobacterial GSTs are reported with the aim of determining their atomic structures. Glutathione S-transferases (GSTs) are a group of multifunctional enzymes that are found in animals, plants and microorganisms. Their primary function is to remove toxins derived from exogenous sources or the products of metabolism from the cell. Mammalian GSTs have been extensively studied, in contrast to bacterial GSTs which have received relatively scant attention. A new class of GSTs called Chi has recently been identified in cyanobacteria. Chi GSTs exhibit a high glutathionylation activity towards isothiocyanates, compounds that are normally found in plants. Here, the crystallization of two GSTs are presented: TeGST produced by Thermosynechococcus elongates BP-1 and SeGST from Synechococcus elongates PCC 6301. Both enzymes formed crystals that diffracted to high resolution and appeared to be suitable for further X-ray diffraction studies. The structures of these GSTs may shed further light on the evolution of GST catalytic activity and in particular why these enzymes possess catalytic activity towards plant antimicrobial compounds

  7. Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea.

    Science.gov (United States)

    Vijayakumar, Harshavardhanan; Thamilarasan, Senthil Kumar; Shanmugam, Ashokraj; Natarajan, Sathishkumar; Jung, Hee-Jeong; Park, Jong-In; Kim, HyeRan; Chung, Mi-Young; Nou, Ill-Sup

    2016-01-01

    Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18) are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS). Currently, understanding of their function(s) during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST) and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible) under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT) and cold susceptible (CS) lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants. PMID:27472324

  8. Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea

    Directory of Open Access Journals (Sweden)

    Harshavardhanan Vijayakumar

    2016-07-01

    Full Text Available Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18 are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS. Currently, understanding of their function(s during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT and cold susceptible (CS lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants.

  9. Structure of Human O-GlcNAc Transferase and its Complex with a Peptide Substrate

    Energy Technology Data Exchange (ETDEWEB)

    M Lazarus; Y Nam; J Jiang; P Sliz; S Walker

    2011-12-31

    The essential mammalian enzyme O-linked {beta}-N-acetylglucosamine transferase (O-GlcNAc transferase, here OGT) couples metabolic status to the regulation of a wide variety of cellular signalling pathways by acting as a nutrient sensor. OGT catalyses the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine (UDP-GlcNAc) to serines and threonines of cytoplasmic, nuclear and mitochondrial proteins, including numerous transcription factors, tumour suppressors, kinases, phosphatases and histone-modifying proteins. Aberrant glycosylation by OGT has been linked to insulin resistance, diabetic complications, cancer and neurodegenerative diseases including Alzheimer's. Despite the importance of OGT, the details of how it recognizes and glycosylates its protein substrates are largely unknown. We report here two crystal structures of human OGT, as a binary complex with UDP (2.8 {angstrom} resolution) and as a ternary complex with UDP and a peptide substrate (1.95 {angstrom}). The structures provide clues to the enzyme mechanism, show how OGT recognizes target peptide sequences, and reveal the fold of the unique domain between the two halves of the catalytic region. This information will accelerate the rational design of biological experiments to investigate OGT's functions; it will also help the design of inhibitors for use as cellular probes and help to assess its potential as a therapeutic target.

  10. Conductimetric assays for the hydrolase and transferase activities of phospholipase D enzymes.

    Science.gov (United States)

    Mezna, M; Lawrence, A J

    1994-05-01

    Measurement of solution electrical conductance (conductimetry) is a simple direct assay method for the protogenic, hydrolytic reactions catalyzed by all phospholipase enzymes. The technique is especially suitable for assay of phospholipase D (PLD) enzymes where cleavage of zwitterionic substrates reinforces the pH dependent conductance change and allows the method to be used over a much wider pH range than the equivalent titrimetric assay. The ability to detect zwitterion cleavage enables the method to assay reactions in which phospholipase D transfers neutral, or anionic, alcohol species to the zwitterionic substrates phosphatidyl choline and phosphatidyl ethanolamine. The method can follow the sequential attack by different phospholipases and provides a simple technique for investigating the effect of substrate structure on susceptibility to various phospholipase enzymes. The results confirm that PLD from Streptomyces chromofuscus can attack lysophospholipids, but cannot transfer primary alcohols to the phosphatidyl residue, while the PLD from savoy cabbage is an efficient transferase, but cannot attack lysophospholipids. The data suggest that the bacterial PLD fails to act as a transferase because it hydrolyzes the transphosphatidylation products. Some phosphatidyl alcohols are more highly susceptible to PLA2 attack than the parent phosphatidyl choline derivatives.

  11. Mice Deficient in Glutathione Transferase Zeta/Maleylacetoacetate Isomerase Exhibit a Range of Pathological Changes and Elevated Expression of Alpha, Mu, and Pi Class Glutathione Transferases

    Science.gov (United States)

    Lim, Cindy E.L.; Matthaei, Klaus I.; Blackburn, Anneke C.; Davis, Richard P.; Dahlstrom, Jane E.; Koina, Mark E.; Anders, M.W.; Board, Philip G.

    2004-01-01

    Glutathione transferase zeta (GSTZ1-1) is the major enzyme that catalyzes the metabolism of α-halo acids such as dichloroacetic acid, a carcinogenic contaminant of chlorinated water. GSTZ1-1 is identical with maleylacetoacetate isomerase, which catalyzes the penultimate step in the catabolic pathways for phenylalanine and tyrosine. In this study we have deleted the Gstz1 gene in BALB/c mice and characterized their phenotype. Gstz1−/− mice do not have demonstrable activity with maleylacetone and α-halo acid substrates, and other GSTs do not compensate for the loss of this enzyme. When fed a standard diet, the GSTZ1-1-deficient mice showed enlarged liver and kidneys as well as splenic atrophy. Light and electron microscopic examination revealed multifocal hepatitis and ultrastructural changes in the kidney. The addition of 3% (w/v) phenylalanine to the drinking water was lethal for young mice (<28 days old) and caused liver necrosis, macrovesicular steatosis, splenic atrophy, and a significant loss of circulating leukocytes in older surviving mice. GSTZ1-1-deficient mice showed constitutive induction of alpha, mu, and pi class GSTs as well as NAD(P)H:quinone oxidoreductase 1. The overall response is consistent with the chronic accumulation of a toxic metabolite(s). We detected the accumulation of succinylacetone in the serum of deficient mice but cannot exclude the possibility that maleylacetoacetate and maleylacetone may also accumulate. PMID:15277241

  12. A study of the prognostic role of serum fucose and fucosyl transferase in cancer of the uterine cervix.

    Directory of Open Access Journals (Sweden)

    Sen,Urmi

    1985-04-01

    Full Text Available Serum fucose levels and fucosyl transferase activities have been designated as nonspecific markers of malignancy, and play an important role in the diagnosis of different types of malignancies. In the present study, attempts were made to determine the prognostic significance of these markers in patients with cancer of the uterine cervix after therapy. It was found that both serum fucose and fucosyl transferase, which were elevated in untreated patients declined significantly in patients responsive to therapy at different follow-up intervals, but not in patients unresponsive to therapy.

  13. IDENTIFYING GENES CONTROLLING FERULATE CROSS-LINKING FORMATION IN GRASS CELL WALLS

    Energy Technology Data Exchange (ETDEWEB)

    de O Buanafina, Marcia Maria

    2013-10-16

    formation or genes encoding transcription factors that control feruloylation. So it will require further investigations to confirm if we have a mutation on the ferulloyltransferase gene(s). We have also identified severe phenotypes which showed a significant change in the level of cell wall ferulates and sugars and have not survived. As this genotype did not reach flowering stage there was no seed production and so further analysis could not be done. 3. Candidate Gene Approach: Because of the likely long time expected to generate and identify candidate with mutation(s) on the feruloyltransferase gene, from our screening, we have in addition taken a bioinformatics approach in order to try to identify candidates gene(s) involved in feruloylation. Homologues of the rice feruloyl transferase genes belonging to Pfam PF02458 family were identified in Brachypodium distachyon by blasting EST sequences of putative rice arabinoxylan feruloyl transferase genes against Brachypodium and homologous sequences identified were tested for their expression level in Brachypodium. Sequences of the two Brachypodium genes, which showed highest expression and similarity to rice sequences, were used to design primers for construction of RNAi and over-expression vectors. These were transformed into Brachypodium using Agrobacterium transformation and plants generated have been analyzed for levels of cell wall ferulates and diferulates over generations T0 to T2 or T3. Our data shows a significant reduction if ferulates monomers and dimers from plants generated from RNAi::BdAT2 over 2-3 generations indicating that this gene might be a positive candidate for feruloylation in Brachypodium. However when BdAT2 was up regulated there was not much increase in the level of ferulates as would be expected. This lack of effect on the level of cell wall ferulates could be due to the CaMV::35S promoter used to drive the expression of the putative BdAT2 gene. We have shown previously that Aspergillus FAEA

  14. Glutathione S-transferases variants as risk factors in Alzheimer's disease.

    Science.gov (United States)

    Wang, Tengfei

    2015-10-01

    Glutathione S-transferase (GST) was suggested as an important contributor to Alzheimer's disease (AD). The GSTs polymorphisms have been investigated as candidate genetic risk factors for AD, yet results remained uncertain. Therefore, we performed a meta-analysis to clarify the relationship of GSTs polymorphisms with the occurrence of AD. PubMed, Embase, Cochrane library and Alzgene databases were searched and potential literatures were selected. Pooled analyses and subgroup analyses were conducted, and also publication bias tests and cumulative meta-analysis. This meta-analysis suggested null associations between polymorphisms of GSTM1, GSTT1, GSTM3, GSTP1, GSTO1 and AD risk. GSTs variants may not have an impact on the morbidity of Alzheimer's disease. Further well designed researches are required to confirm these findings of the current study. PMID:25981226

  15. Atypical features of a Ure2p glutathione transferase from Phanerochaete chrysosporium.

    Science.gov (United States)

    Thuillier, Anne; Roret, Thomas; Favier, Frédérique; Gelhaye, Eric; Jacquot, Jean-Pierre; Didierjean, Claude; Morel-Rouhier, Mélanie

    2013-07-11

    Glutathione transferases (GSTs) are known to transfer glutathione onto small hydrophobic molecules in detoxification reactions. The GST Ure2pB1 from Phanerochaete chrysosporium exhibits atypical features, i.e. the presence of two glutathione binding sites and a high affinity towards oxidized glutathione. Moreover, PcUre2pB1 is able to efficiently deglutathionylate GS-phenacylacetophenone. Catalysis is not mediated by the cysteines of the protein but rather by the one of glutathione and an asparagine residue plays a key role in glutathione stabilization. Interestingly PcUre2pB1 interacts in vitro with a GST of the omega class. These properties are discussed in the physiological context of wood degrading fungi.

  16. Pharmacogenetics of azathioprine in inflammatory bowel disease: a role for glutathione-S-transferase?

    Science.gov (United States)

    Stocco, Gabriele; Pelin, Marco; Franca, Raffaella; De Iudicibus, Sara; Cuzzoni, Eva; Favretto, Diego; Martelossi, Stefano; Ventura, Alessandro; Decorti, Giuliana

    2014-04-01

    Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

  17. Theoretical Study on GSH Activation Mechanism of a New Type of Glutathione Transferase Gtt2

    Institute of Scientific and Technical Information of China (English)

    LI Xue; WU Yun-jian; LI Zhuo; CHU Wen-ting; ZHANG Hong-xing; ZHENG Qing-chuan

    2012-01-01

    Glutathione transferases(GSTs) play an important role in the detoxification of xenobiotic/endobiotic toxic compounds.The a-,π-,and μ-classes of cytosolic GSTs have been studied extensively,while Gtt2 from Saccharomyces cerevisiae,a novel atypical GST,is still poorly understood.In the present study,we investigated the glutathione(GSH) activation mechanism of Gtt2 using the density functional theory(DFT) with the hybrid functional B3LYP.The computational results show that a water molecule could assist a proton transfer between the GSH thiol and the N atom of His133.The energy barrier of proton transfer is 46.0 kJ/mol.The GSH activation mechanism and the characteristics of active site are different from those of classic cytosolic GSTs.

  18. Structural basis for the interaction of antibiotics with peptidyl transferase center in eubacteria

    Energy Technology Data Exchange (ETDEWEB)

    Schlunzen, Frank; Zarivach, Raz; Harms, Jörg; Bashan, Anat; Tocilj, Ante; Albrecht, Renate; Yonath, Ada; Franceschi, Francois (WIS-I); (Max Planck Germany)

    2009-10-07

    Ribosomes, the site of protein synthesis, are a major target for natural and synthetic antibiotics. Detailed knowledge of antibiotic binding sites is central to understanding the mechanisms of drug action. Conversely, drugs are excellent tools for studying the ribosome function. To elucidate the structural basis of ribosome-antibiotic interactions, we determined the high-resolution X-ray structures of the 50S ribosomal subunit of the eubacterium Deinococcus radiodurans, complexed with the clinically relevant antibiotics chloramphenicol, clindamycin and the three macrolides erythromycin, clarithromycin and roxithromycin. We found that antibiotic binding sites are composed exclusively of segments of 23S ribosomal RNA at the peptidyl transferase cavity and do not involve any interaction of the drugs with ribosomal proteins. Here we report the details of antibiotic interactions with the components of their binding sites. Our results also show the importance of putative Mg{sup +2} ions for the binding of some drugs. This structural analysis should facilitate rational drug design.

  19. Response of Glutathione and Glutathione S-transferase in Rice Seedlings Exposed to Cadmium Stress

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hua; GE Ying

    2008-01-01

    A hydroponic culture experiment was done to investigate the effect of Cd stress on glutathione content(GSH)and glutathione S-transferase(GST,EC 2.5.1.18)activity in rice seedlings.The rice growth was severely inhibited when Cd level in the solution was higher than 10 mg/L.In rice shoots,GSH content and GST activity increased with the increasing Cd level,while in roots,GST was obviously inhibited by Cd treatments.Compared with shoots,the rice roots had higher GSH content and GST activity,indicating the ability of Cd detoxification was much higher in roots than in shoots.There was a significant correlation between Cd level and GSH content or GST activity,suggesting that both parameters may be used as biomarkers of Cd stress in rice.

  20. Probing functions of the ribosomal peptidyl transferase center by nucleotide analog interference.

    Science.gov (United States)

    Erlacher, Matthias D; Polacek, Norbert

    2012-01-01

    The ribosome is a huge ribonucleoprotein complex in charge of protein synthesis in every living cell. The catalytic center of this dynamic molecular machine is entirely built up of 23S ribosomal RNA and therefore the ribosome can be referred to as the largest natural ribozyme known so far. The in vitro reconstitution approach of large ribosomal subunits described herein allows nucleotide analog interference studies to be performed. The approach is based on the site-specific introduction of nonnatural nucleotide analogs into the peptidyl transferase center, the active site located on the interface side of the large ribosomal subunit. This method combined with standard tests of ribosomal functions broadens the biochemical repertoire to investigate the mechanism of diverse aspects of translation considerably and adds another layer of molecular information on top of structural and mutational studies of the ribosome. PMID:22315072

  1. Crystal structure of Glycine max glutathione transferase in complex with glutathione: investigation of the mechanism operating by the Tau class glutathione transferases.

    Science.gov (United States)

    Axarli, Irene; Dhavala, Prathusha; Papageorgiou, Anastassios C; Labrou, Nikolaos E

    2009-08-13

    Cytosolic GSTs (glutathione transferases) are a multifunctional group of enzymes widely distributed in Nature and involved in cellular detoxification processes. The three-dimensional structure of GmGSTU4-4 (Glycine max GST Tau 4-4) complexed with GSH was determined by the molecular replacement method at 2.7 A (1 A=0.1 nm) resolution. The bound GSH is located in a region formed by the beginning of alpha-helices H1, H2 and H3 in the N-terminal domain of the enzyme. Significant differences in the G-site (GSH-binding site) as compared with the structure determined in complex with Nb-GSH [S-(p-nitrobenzyl)-glutathione] were found. These differences were identified in the hydrogen-bonding and electrostatic interaction pattern and, consequently, GSH was found bound in two different conformations. In one subunit, the enzyme forms a complex with the ionized form of GSH, whereas in the other subunit it can form a complex with the non-ionized form. However, only the ionized form of GSH may form a productive and catalytically competent complex. Furthermore, a comparison of the GSH-bound structure with the Nb-GSH-bound structure shows a significant movement of the upper part of alpha-helix H4 and the C-terminal. This indicates an intrasubunit modulation between the G-site and the H-site (electrophile-binding site), suggesting that the enzyme recognizes the xenobiotic substrates by an induced-fit mechanism. The reorganization of Arg111 and Tyr107 upon xenobiotic substrate binding appears to govern the intrasubunit structural communication between the G- and H-site and the binding of GSH. The structural observations were further verified by steady-state kinetic analysis and site-directed mutagenesis studies.

  2. A glutathione transferase from Agrobacterium tumefaciens reveals a novel class of bacterial GST superfamily.

    Directory of Open Access Journals (Sweden)

    Katholiki Skopelitou

    Full Text Available In the present work, we report a novel class of glutathione transferases (GSTs originated from the pathogenic soil bacterium Agrobacterium tumefaciens C58, with structural and catalytic properties not observed previously in prokaryotic and eukaryotic GST isoenzymes. A GST-like sequence from A. tumefaciens C58 (Atu3701 with low similarity to other characterized GST family of enzymes was identified. Phylogenetic analysis showed that it belongs to a distinct GST class not previously described and restricted only in soil bacteria, called the Eta class (H. This enzyme (designated as AtuGSTH1-1 was cloned and expressed in E. coli and its structural and catalytic properties were investigated. Functional analysis showed that AtuGSTH1-1 exhibits significant transferase activity against the common substrates aryl halides, as well as very high peroxidase activity towards organic hydroperoxides. The crystal structure of AtuGSTH1-1 was determined at 1.4 Å resolution in complex with S-(p-nitrobenzyl-glutathione (Nb-GSH. Although AtuGSTH1-1 adopts the canonical GST fold, sequence and structural characteristics distinct from previously characterized GSTs were identified. The absence of the classic catalytic essential residues (Tyr, Ser, Cys distinguishes AtuGSTH1-1 from all other cytosolic GSTs of known structure and function. Site-directed mutagenesis showed that instead of the classic catalytic residues, an Arg residue (Arg34, an electron-sharing network, and a bridge of a network of water molecules may form the basis of the catalytic mechanism. Comparative sequence analysis, structural information, and site-directed mutagenesis in combination with kinetic analysis showed that Phe22, Ser25, and Arg187 are additional important residues for the enzyme's catalytic efficiency and specificity.

  3. A glutathione transferase from Agrobacterium tumefaciens reveals a novel class of bacterial GST superfamily.

    Science.gov (United States)

    Skopelitou, Katholiki; Dhavala, Prathusha; Papageorgiou, Anastassios C; Labrou, Nikolaos E

    2012-01-01

    In the present work, we report a novel class of glutathione transferases (GSTs) originated from the pathogenic soil bacterium Agrobacterium tumefaciens C58, with structural and catalytic properties not observed previously in prokaryotic and eukaryotic GST isoenzymes. A GST-like sequence from A. tumefaciens C58 (Atu3701) with low similarity to other characterized GST family of enzymes was identified. Phylogenetic analysis showed that it belongs to a distinct GST class not previously described and restricted only in soil bacteria, called the Eta class (H). This enzyme (designated as AtuGSTH1-1) was cloned and expressed in E. coli and its structural and catalytic properties were investigated. Functional analysis showed that AtuGSTH1-1 exhibits significant transferase activity against the common substrates aryl halides, as well as very high peroxidase activity towards organic hydroperoxides. The crystal structure of AtuGSTH1-1 was determined at 1.4 Å resolution in complex with S-(p-nitrobenzyl)-glutathione (Nb-GSH). Although AtuGSTH1-1 adopts the canonical GST fold, sequence and structural characteristics distinct from previously characterized GSTs were identified. The absence of the classic catalytic essential residues (Tyr, Ser, Cys) distinguishes AtuGSTH1-1 from all other cytosolic GSTs of known structure and function. Site-directed mutagenesis showed that instead of the classic catalytic residues, an Arg residue (Arg34), an electron-sharing network, and a bridge of a network of water molecules may form the basis of the catalytic mechanism. Comparative sequence analysis, structural information, and site-directed mutagenesis in combination with kinetic analysis showed that Phe22, Ser25, and Arg187 are additional important residues for the enzyme's catalytic efficiency and specificity.

  4. The glutathione-S-transferase Mu 1 null genotype modulates ozone-induced airway inflammation in humans*

    Science.gov (United States)

    Background: The Glutathione-S-Transferase Mu 1 null genotype has been reported to be a risk factor for acute respiratory disease associated with increases in ambient air ozone. Ozone is known to cause an immediate decrease in lung function and increased airway inflammation. Howev...

  5. Characterization of the hydrophobic substrate-binding site of the bacterial beta class glutathione transferase from Proteus mirabilis.

    Science.gov (United States)

    Federici, Luca; Masulli, Michele; Di Ilio, Carmine; Allocati, Nerino

    2010-09-01

    Since their discovery, bacterial glutathione (GSH)transferases have been characterized in terms of their ability to catalyse a variety of different reactions on a large set of toxic molecules of xenobiotic or endobiotic origin. Furthermore the contribution of different residues in the GSH-binding site to GSH activation has been extensively investigated. Little is known, however, about the contribution to catalysis and overall stability of single residues shaping the hydrophobic co-substrate binding site (H-site). Here we tackle this problem by site-directed mutagenesis of residues facing the H-site in the bacterial beta class GSH transferase from Proteus mirabilis. We investigate the behaviour of these mutants under a variety of conditions and analyse their activity against several co-substrates, representative of the different reactions catalyzed by bacterial GSH transferases. Our work shows that mutations at the H-site can be used to modulate activity at the level of the different catalytic mechanisms operating on the chosen substrates, each mutation showing a different fingerprint. This work paves the way for future studies aimed at improving the catalytic properties of beta class GSH transferases against selected substrates for bioremediation purposes.

  6. Selection of Arabidopsis mutants overexpressing genes driven by the promoter of an auxin-inducible glutathione S-transferase gene

    NARCIS (Netherlands)

    Kop, D.A.M. van der; Schuyer, M.; Pinas, J.E.; Zaal, B.J. van der; Hooykaas, P.J.J.

    1999-01-01

    Transgenic arabidopsis plants were isolated that contained a T-DNA construct in which the promoter of an auxin-inducible glutathione S-transferase (GST) gene from tobacco was fused to the kanamycin resistance (nptII) as well as to the β-glucuronidase (gusA) reporter gene. Subsequently, seeds were tr

  7. Tet Proteins Connect the O-Linked N-acetylglucosamine Transferase Ogt to Chromatin in Embryonic Stem Cells

    DEFF Research Database (Denmark)

    Vella, Pietro; Scelfo, Andrea; Jammula, Sriganesh;

    2013-01-01

    O-linked N-acetylglucosamine (O-GlcNAc) transferase (Ogt) activity is essential for embryonic stem cell (ESC) viability and mouse development. Ogt is present both in the cytoplasm and the nucleus of different cell types and catalyzes serine and threonine glycosylation. We have characterized...

  8. CT-GalNAc transferase overexpression in adult mice is associated with extrasynaptic utrophin in skeletal muscle fibres.

    Science.gov (United States)

    Durko, Margaret; Allen, Carol; Nalbantoglu, Josephine; Karpati, George

    2010-09-01

    Duchenne muscular dystrophy is a genetic muscle disease characterized by the absence of sub-sarcolemmal dystrophin that results in muscle fibre necrosis, progressive muscle wasting and is fatal. Numerous experimental studies with dystrophin-deficient mdx mice, an animal model for the disease, have demonstrated that extrasynaptic upregulation of utrophin, an analogue of dystrophin, can prevent muscle fibre deterioration and reduce or negate the dystrophic phenotype. A different approach for ectopic expression of utrophin relies on augmentation of CT-GalNAc transferase in muscle fibre. We investigated whether CT-GalNAc transferase overexpression in adult mice influence appearance of utrophin in the extrasynaptic sarcolemma. After electrotransfer of plasmid DNA carrying an expression cassette of CT-GalNAc transferase into tibialis anterior muscle of wild type and dystrophic mice, muscle sections were examined by immunofluorescence. CT-GalNAc transgene expression augmented sarcolemmal carbohydrate glycosylation and was accompanied by extrasynaptic utrophin. A 6-week time course study showed that the highest efficiency of utrophin overexpression in a plasmid harboured muscle fibres was 32.2% in CD-1 and 52% in mdx mice, 2 and 4 weeks after CT-GalNAc gene transfer, respectively. The study provides evidence that postnatal CT-GalNAc transferase overexpression stimulates utrophin upregulation that is inherently beneficial for muscle structure and strength restoration. Thus CT-GalNAc may provide an important therapeutic molecule for treatment of dystrophin deficiency in Duchenne muscular dystrophy.

  9. Immunohistochemical localization of glutathione-S-transferase and glutathione peroxidase in adult Syrian hamster tissues and during kidney development.

    OpenAIRE

    Oberley, T. D.; Oberley, L. W.; Slattery, A. F.; Elwell, J. H.

    1991-01-01

    Tissues from adult Syrian hamsters were studied with immunoperoxidase techniques using polyclonal antibodies to glutathione-S-transferase (rat liver and human placental enzymes) and human erythrocyte glutathione peroxidase. Most tissues immunostained similarly with these antibodies. Most notable was the cytoplasmic staining of mesenchyme tissues, especially smooth muscle, by all three antibodies. Epithelial cells stained distinctively, but usually less intensely than mesenchyme. Epithelial ce...

  10. Systemic catechol-O-methyl transferase inhibition enables the D1 agonist radiotracer R-[11C]SKF 82957

    DEFF Research Database (Denmark)

    Palner, Mikael; McCormick, Patrick; Parkes, Jun;

    2010-01-01

    R-[(11)C]-SKF 82957 is a high-affinity and potent dopamine D(1) receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway...

  11. Crystal structure of a murine α-class glutathione S-transferase involved in cellular defense against oxidative stress

    NARCIS (Netherlands)

    Krengel, Ute; Schröter, Klaus-Hasso; Hoier, Helga; Arkema, Anita; Kalk, Kor H.; Zimniak, Piotr; Dijkstra, Bauke W.

    1998-01-01

    Glutathione S-transferases (GSTs) are ubiquitous multifunctional enzymes which play a key role in cellular detoxification. The enzymes protect the cells against toxicants by conjugating them to glutathione. Recently, a novel subgroup of α-class GSTs has been identified with altered substrate specifi

  12. LIGNIFICATION IN TRANSGENICS DEFICIENT IN P-COUMARATE 3-HYDROXYLASE (C3H) AND THE ASSOCIATED HYDROXYCINNAMOYL TRANSFERASE (HCT)

    Science.gov (United States)

    The effects on lignification of downregulating most of the genes for enzymes on the monolignol biosynthetic pathway have been reasonably well studied in angiosperms. The exception to this is the crucial hydroxylase, cinnamate 3-hydroxylase (C3H), and its associated hydroxycinnamyl transferase (HCT),...

  13. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of health claims related to arabinoxylan produced from wheat endosperm and reduction of post-prandial glycaemic responses (ID 830) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to provide a scientific opinion on a list of health claims pursuant to Article 13 of Regulation (EC) No 1924/2006. This opinion addresses the scientific substantiation of a health...... claim in relation to arabinoxylan produced from wheat endosperm and reduction of post-prandial glycaemic responses. The scientific substantiation is based on the information provided by the Member States in the consolidated list of Article 13 health claims and references that EFSA has received from...... responses. The Panel considers that the reduction of post-prandial glycaemic responses (as long as post-prandial insulinaemic responses are not disproportionally increased) may be a beneficial physiological effect. In weighing the evidence, the Panel took into account that one well-designed intervention...

  14. Structural snapshots along the reaction pathway of Yersinia pestis RipA, a putative butyryl-CoA transferase

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Rodrigo; Lan, Benson; Latif, Yama; Chim, Nicholas [UC Irvine, 2212 Natural Sciences I, Irvine, CA 92697 (United States); Goulding, Celia W., E-mail: celia.goulding@uci.edu [UC Irvine, 2212 Natural Sciences I, Irvine, CA 92697 (United States); UC Irvine, 2302 Natural Sciences I, Irvine, CA 92697 (United States)

    2014-04-01

    The crystal structures of Y. pestis RipA mutants were determined to provide insights into the CoA transferase reaction pathway. Yersinia pestis, the causative agent of bubonic plague, is able to survive in both extracellular and intracellular environments within the human host, although its intracellular survival within macrophages is poorly understood. A novel Y. pestis three-gene rip (required for intracellular proliferation) operon, and in particular ripA, has been shown to be essential for survival and replication in interferon γ-induced macrophages. RipA was previously characterized as a putative butyryl-CoA transferase proposed to yield butyrate, a known anti-inflammatory shown to lower macrophage-produced NO levels. RipA belongs to the family I CoA transferases, which share structural homology, a conserved catalytic glutamate which forms a covalent CoA-thioester intermediate and a flexible loop adjacent to the active site known as the G(V/I)G loop. Here, functional and structural analyses of several RipA mutants are presented in an effort to dissect the CoA transferase mechanism of RipA. In particular, E61V, M31G and F60M RipA mutants show increased butyryl-CoA transferase activities when compared with wild-type RipA. Furthermore, the X-ray crystal structures of E61V, M31G and F60M RipA mutants, when compared with the wild-type RipA structure, reveal important conformational changes orchestrated by a conserved acyl-group binding-pocket phenylalanine, Phe85, and the G(V/I)G loop. Binary structures of M31G RipA and F60M RipA with two distinct CoA substrate conformations are also presented. Taken together, these data provide CoA transferase reaction snapshots of an open apo RipA, a closed glutamyl-anhydride intermediate and an open CoA-thioester intermediate. Furthermore, biochemical analyses support essential roles for both the catalytic glutamate and the flexible G(V/I)G loop along the reaction pathway, although further research is required to fully

  15. Orotate phosphoribosyl transferase mRNA expression and the response of cholangiocarcinoma to 5-fluorouracil

    Institute of Scientific and Technical Information of China (English)

    Chariya Hahnvajanawong; Jariya Chaiyagool; Wunchana Seubwai; Vajarabhongsa Bhudhisawasdi; Nisana Namwat; Narong Khuntikeo; Banchob Sripa

    2012-01-01

    AIM:To determine whether expression of certain enzymes related to 5-fluorouracil (5-FU) metabolism predicts 5-FU chemosensitivity in cholangiocarcinoma (CCA).METHODS:The histoculture drug response assay (HDRA) was performed using surgically resected CCA tissues.Tumor cell viability was determined morphologically with hematoxylin and eosin-and terminal deoxynucleotide transferase-mediated dUTP nick-end labeling-stained tissues.The mRNA expression of thymidine phosphorylase (TP),orotate phosphoribosyl transferase (OPRT),thymidylate synthase (TS),and dihydropyrimidine dehydrogenase (DPD) was determined with realtime reverse transcriptase-polymerase chain reaction.The levels of gene expression and the sensitivity to 5-FU were evaluated.RESULTS:Twenty-three CCA tissues were obtained from patients who had been diagnosed with intrahepatic CCA and who underwent surgical resection at Srinagarind Hospital,Khon Kaen University from 2007 to 2009.HDRA was used to determine the response of these CCA tissues to 5-FU.Based on the dose-response curve,200 μg/mL 5-FU was selected as the test concentration.The percentage of inhibition index at the median point was selected as the cut-off point to differentiate the responding and non-responding tumors to 5-FU.When the relationship between TP,OPRT,TS and DPD mRNA expression levels and the sensitivity of CCA tissues to 5-FU was examined,only OPRT mRNA expression was significantly correlated with the response to 5-FU.The mean expression level of OPRT was significantly higher in the responder group compared to the non-responder group (0.41 ± 0.25 vs 0.22 ± 0.12,P < 0.05).CONCLUSION:OPRT mRNA expression may be a useful predictor of 5-FU chemosensitivity of CCA.Whether OPRT mRNA could be used to predict the success of 5-FU chemotherapy in CCA patients requires confirmation in patients.

  16. Heterologous expression and functional characterization of avian mu-class glutathione S-transferases.

    Science.gov (United States)

    Bunderson, Brett R; Kim, Ji Eun; Croasdell, Amanda; Mendoza, Kristelle M; Reed, Kent M; Coulombe, Roger A

    2013-08-01

    Hepatic glutathione S-transferases (GSTs: EC2.5.1.1.8) catalyze the detoxification of reactive electrophilic compounds, many of which are toxic and carcinogenic intermediates, via conjugation with the endogenous tripeptide glutathione (GSH). Glutathione S-transferase (GST)-mediated detoxification is a critical determinant of species susceptibility to the toxic and carcinogenic mycotoxin aflatoxin B1 (AFB1), which in resistant animals efficiently detoxifies the toxic intermediate produced by hepatic cytochrome P450 bioactivation, the exo-AFB1-8,9-epoxide (AFBO). Domestic turkeys (Meleagris gallopavo) are one of the most sensitive animals known to AFB1, a condition associated with a deficiency of hepatic GST-mediated detoxification of AFBO. We have recently shown that unlike their domestic counterparts, wild turkeys (Meleagris gallopavo silvestris), which are relatively resistant, express hepatic GST-mediated detoxification activity toward AFBO. Because of the importance of GSTs in species susceptibility, and to explore possible GST classes involved in AFB1 detoxification, we amplified, cloned, expressed and functionally characterized the hepatic mu-class GSTs tGSTM3 (GenBank accession no. JF340152), tGSTM4 (JF340153) from domestic turkeys, and a GSTM4 variant (ewGSTM4, JF340154) from Eastern wild turkeys. Predicted molecular masses of tGSTM3 and two tGSTM4 variants were 25.6 and 25.8kDa, respectively. Multiple sequence comparisons revealed four GSTM motifs and the mu-loop in both proteins. tGSTM4 has 89% amino acid sequence identity to chicken GSTM2, while tGSTM3 has 73% sequence identity to human GSTM3 (hGSTM3). Specific activities of Escherichia coli-expressed tGSTM3 toward 1-chloro-2,4-dinitrobenzene (CDNB) and peroxidase activity toward cumene hydroperoxide were five-fold greater than tGSTM4 while tGSTM4 possessed more than three-fold greater activity toward 1,2-dichloro-4-nitrobenzene (DCNB). The two enzymes displayed equal activity toward ethacrynic acid (ECA

  17. Two Pear Glutathione S-Transferases Genes Are Regulated during Fruit Development and Involved in Response to Salicylic Acid, Auxin, and Glucose Signaling

    OpenAIRE

    Hai-Yan Shi; Zheng-Hong Li; Yu-Xing Zhang; Liang Chen; Di-Ying Xiang; Yu-Feng Zhang

    2014-01-01

    Two genes encoding putative glutathione S-transferase proteins were isolated from pear (Pyrus pyrifolia) and designated PpGST1 and PpGST2. The deduced PpGST1 and PpGST2 proteins contain conserved Glutathione S-transferase N-terminal domain (GST_N) and Glutathione S-transferase, C-terminal domain (GST_C). Using PCR amplification technique, the genomic clones corresponding to PpGST1 and PpGST2 were isolated and shown to contain two introns and a singal intron respectively with typical GT/AG bou...

  18. Fast non-chromatographic method to assay for xanthine-guanosine phosphoribosyl transferase

    Energy Technology Data Exchange (ETDEWEB)

    Fromont-Racine, M.; Pictet, R. (Universite Paris (France))

    1988-07-25

    The authors have compared two methods to separate xanthine (X) from xanthine monophosphate (XMP) in the xanthine-guanine phosphoribosyl transferase (XGPRT) assay. XGPRT, product of the bacterial gene Ecogpt is widely used in experiments using DNA transfer into mammalian cells as a marker enzyme to estimate promoter activity as well as to select recombinant cells. The usual method adopted to assay for XGPRT is to separate phosphorylated from unphosphorylated substrate by thin layer chromatography; after detection by autoradiography, the spots are cut and counted. Another way of separation is to spot the reaction mixture directly onto polyethyleneimine impregnated cellulose sheets. The XMP binds to the support and the unphosphorylated X is washed away with 0.1 M ammonium acetate. The first procedure, beside protein extraction, necessitates 4h chromatography and {approximately} 18h autoradiography while the second takes only 1h; thus the second should be the method of choice provided that the level of detection be as good. They report that indeed it combines sensitivity and reduced time.

  19. Role of glutathione S-transferases in the spinocerebellar ataxia type 2 clinical phenotype.

    Science.gov (United States)

    Almaguer-Gotay, D; Almaguer-Mederos, L E; Aguilera-Rodríguez, R; Estupiñán-Rodríguez, A; González-Zaldivar, Y; Cuello-Almarales, D; Laffita-Mesa, J M; Vázquez-Mojena, Y

    2014-06-15

    Spinocerebellar ataxia type 2 (SCA2) is a neurodegenerative and incurable hereditary disorder caused by a CAG repeat expansion mutation on ATXN2 gene. The identification of reliable biochemical markers of disease severity is of paramount significance for the development and assessment of clinical trials. In order to evaluate the potential use of glutathione-S-transferase (GST) activity as a biomarker for SCA2, a case-control study in 38 affected, presymptomatic individuals or healthy controls was conducted. An enlarged sample of 121 affected individuals was set to assess the impact of GST activity on SCA2 clinical expression. There was a significant increase in GST activity in affected individuals relative to controls, although sensibility and specificity were not high. GST activity was not significantly influenced by sex, age, disease duration or CAG repeat size and did not significantly influence disease severity markers. These findings show a disruption of in vivo GST activity in SCA2, suggesting a role for oxidative stress in the neurodegenerative process. PMID:24780439

  20. Molecular characterization of zeta class glutathione S-transferases from Pinus brutia Ten.

    Indian Academy of Sciences (India)

    E. Oztetik; F. Kockar; M. Alper; M. Iscan

    2015-09-01

    Glutathione transferases (GSTs; EC 2.5.1.18) play important roles in stress tolerance and metabolic detoxification in plants. In higher plants, studies on GSTs have focussed largely on agricultural plants. There is restricted information about molecular characterization of GSTs in gymnosperms. To date, only tau class GST enzymes have been characterized from some pinus species. For the first time, the present study reports cloning and molecular characterization of two zeta class GST genes, namely PbGSTZ1 and PbGSTZ2 from Pinus brutia Ten., which is an economically important pine native to the eastern Mediterranean region and have to cope with several environmental stress conditions. The PbGSTZ1 gene was isolated from cDNA, whereas PbGSTZ2 was isolated from genomic DNA. Sequence analysis of PbGSTZ1 and PbGSTZ2 revealed the presence of an open reading frame of 226 amino acids with typical consensus sequences of the zeta class plant GSTs. Protein and secondary structure prediction analysis of two zeta class PbGSTZs have shared common features of other plant zeta class GSTs. Genomic clone, PbGSTZ2 gene, is unexpectedly intronless. Extensive sequence analysis of PbGSTZ2, with cDNA clone, PbGSTZ1, revealed 87% identity at nucleotide and 81% identity at amino acid levels with 41 amino acids differences suggesting that genomic PbGSTZ2 gene might be an allelic or a paralogue version of PbGSTZ1.

  1. Characterization and evolutionary implications of the triad Asp-Xxx-Glu in group II phosphopantetheinyl transferases.

    Directory of Open Access Journals (Sweden)

    Yue-Yue Wang

    Full Text Available Phosphopantetheinyl transferases (PPTases, which play an essential role in both primary and secondary metabolism, are magnesium binding enzymes. In this study, we characterized the magnesium binding residues of all known group II PPTases by biochemical and evolutionary analysis. Our results suggested that group II PPTases could be classified into two subgroups, two-magnesium-binding-residue-PPTases containing the triad Asp-Xxx-Glu and three-magnesium-binding-residue-PPTases containing the triad Asp-Glu-Glu. Mutations of two three-magnesium-binding-residue-PPTases and one two-magnesium-binding-residue-PPTase indicate that the first and the third residues in the triads are essential to activities; the second residues in the triads are non-essential. Although variations of the second residues in the triad Asp-Xxx-Glu exist throughout the whole phylogenetic tree, the second residues are conserved in animals, plants, algae, and most prokaryotes, respectively. Evolutionary analysis suggests that: the animal group II PPTases may originate from one common ancestor; the plant two-magnesium-binding-residue-PPTases may originate from one common ancestor; the plant three-magnesium-binding-residue-PPTases may derive from horizontal gene transfer from prokaryotes.

  2. A glutathione S-transferase gene associated with antioxidant properties isolated from Apis cerana cerana

    Science.gov (United States)

    Liu, Shuchang; Liu, Feng; Jia, Haihong; Yan, Yan; Wang, Hongfang; Guo, Xingqi; Xu, Baohua

    2016-06-01

    Glutathione S-transferases (GSTs) are an important family of multifunctional enzymes in aerobic organisms. They play a crucial role in the detoxification of exogenous compounds, especially insecticides, and protection against oxidative stress. Most previous studies of GSTs in insects have largely focused on their role in insecticide resistance. Here, we isolated a theta class GST gene designated AccGSTT1 from Apis cerana cerana and aimed to explore its antioxidant and antibacterial attributes. Analyses of homology and phylogenetic relationships suggested that the predicted amino acid sequence of AccGSTT1 shares a high level of identity with the other hymenopteran GSTs and that it was conserved during evolution. Quantitative real-time PCR showed that AccGSTT1 is most highly expressed in adult stages and that the expression profile of this gene is significantly altered in response to various abiotic stresses. These results were confirmed using western blot analysis. Additionally, a disc diffusion assay showed that a recombinant AccGSTT1 protein may be roughly capable of inhibiting bacterial growth and that it reduces the resistance of Escherichia coli cells to multiple adverse stresses. Taken together, these data indicate that AccGSTT1 may play an important role in antioxidant processes under adverse stress conditions.

  3. Antioxidant Effect of Selenium-containing Glutathione S-Transferase in Rat Cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    YIN Li; HAN Xiao; YU Yang; GUO Xiao; REN Li-qun; FANG Jing-qi; LIU Zhi-yi; YAN Gang-lin; WEI Jing-yan

    2012-01-01

    As one of the most important antioxidant enzymes,glutathione peroxidase(GPX) protects cells and tissues from oxidative damage,and plays an important role in cardiovascular and cerebrovascular injuries induced by oxidative stress.The antioxidant effect of selenium-containing glutathione S-transferase(Se-GST),a mimic of GPX was investigated on rat cardiomyocytes.To explore the protection function of Se-GST in hydrogen peroxide(H2O2) challenged rat cardiomyocytes,we examined malondialdehyde(MDA),lactate dehydrogenase(LDH),superoxide dismutase(SOD) and cell apoptosis.The results demonstrate exposure of rat cardiomyocytes to H2O2 for 6 and 12 h induced the significant increases of MDA,LDH and apoptosis rate of cardiomyocytes,but pretreatment of rat cardiomyocytes with Se-GST at 0.0005 or 0.001 unit/mL prevents oxidative stress induced by H2O2 with the decreases of cell apoptosis.All the results him Se-GST has antioxidant activity for oxidative stress challenged rat cardiomyocytes.

  4. Purification and Identification of Glutathione S-transferase in Rice Root under Cadmium Stress

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hua; WU Ze-ying; JU Ting; GE Ying

    2013-01-01

    Cadmium (Cd) contamination in paddy soils poses a serious threat to the production and quality of rice.Among various biochemical processes related to Cd detoxification in rice,glutathione S-transferase (GST) plays an important role,catalyzing Cd complexation with glutathione (GSH) and scavenging reactive oxygen species (ROS) in cells.In this study,a hydroponic experiment was conducted to investigate the response of GST isozymes in rice roots upon Cd exposure.Results showed that the GST activity in rice roots was clearly enhanced by 50 μmol/L Cd treatment for 7 d.The GST isozymes were purified by ammonium sulphate precipitation,gel filtration chromatography and affinity chromatography.After being separated by SDS-PAGE and visualized by silver staining,GSTU6 was identified by in-gel digestion,MALDI-TOF-MS analysis and peptide mass fingerprint.The results confirm the vital function of tau class rice GST in Cd detoxification.

  5. Structural insights into the dehydroascorbate reductase activity of human omega-class glutathione transferases.

    Science.gov (United States)

    Zhou, Huina; Brock, Joseph; Liu, Dan; Board, Philip G; Oakley, Aaron J

    2012-07-13

    The reduction of dehydroascorbate (DHA) to ascorbic acid (AA) is a vital cellular function. The omega-class glutathione transferases (GSTs) catalyze several reductive reactions in cellular biochemistry, including DHA reduction. In humans, two isozymes (GSTO1-1 and GSTO2-2) with significant DHA reductase (DHAR) activity are found, sharing 64% sequence identity. While the activity of GSTO2-2 is higher, it is significantly more unstable in vitro. We report the first crystal structures of human GSTO2-2, stabilized through site-directed mutagenesis and determined at 1.9 Å resolution in the presence and absence of glutathione (GSH). The structure of a human GSTO1-1 has been determined at 1.7 Å resolution in complex with the reaction product AA, which unexpectedly binds in the G-site, where the glutamyl moiety of GSH binds. The structure suggests a similar mode of ascorbate binding in GSTO2-2. This is the first time that a non-GSH-based reaction product has been observed in the G-site of any GST. AA stacks against a conserved aromatic residue, F34 (equivalent to Y34 in GSTO2-2). Mutation of Y34 to alanine in GSTO2-2 eliminates DHAR activity. From these structures and other biochemical data, we propose a mechanism of substrate binding and catalysis of DHAR activity.

  6. PLLA-PCys co-electrospun fibers for capture and elution of glutathione S-transferase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The copolymer poly(L-lactic acid)-b-poly(L-cysteine) (PLA-b-PCys) was co-electrospun with PLGA into ultrafine fibers. The reduced glutathione (GSH) was conjugated to the fiber surfaces via disulfide bonds. The glutathione S-transferase (GST) was captured onto the GSH fibers via specific substrate-enzyme interaction between the bound GSH and GST. The captured GST was eluted with free GSH aqueous solution and lyophilized to get pure GST powders. The results show that the GSH moieties on the fiber surface retain the bioactivity of the free GSH and thus they can bind specifically with GST and the GST in solution is captured onto the fiber surface. In addition, the bound GSH is not as active as free GSH so that the captured GST can be eluted off from the fiber by free GSH aqueous solution. Based on this principle, GST itself or its fused proteins can be separated and purified very easily. The preliminary purification efficiency is 6.5 mg·(gPCys)-1. Further improvements are undertaken.

  7. Crystallization and X-ray diffraction studies of glutathione S-transferase from Escherichia coli

    Science.gov (United States)

    Nishida, Motohiko; Harada, Shigeharu; Satow, Yoshinori; Inoue, Hideshi; Takahashi, Kenji

    1996-10-01

    Crystals of glutathione S-transferase from Escherichia coli have been obtained by use of polyethylene glycol 6000 as a precipitant. The crystallization was performed in the presence of a glutathione sulfonate inhibitor under the acidic condition, with combination of the sitting-drop vapour-diffusion and the macro-seeding procedures. The crystals are of a thin-plate shape with typical sizes of 1.0 × 0.5 × 0.1 mm, and are stable against X-ray irradiation. They belong to the space group P2 12 12 1 with cell parameters of a = 90.47 Å, b = 93.87 Å and c = 51.10 Å, and diffract X-rays at least up to 2.3 Å resolution. The solvent content is 48% in volume, when a homodimeric molecule of the enzyme is assumed to occupy an asymmetric unit of the crystal. The crystals are suitable for three-dimensional structural studies. Diffraction data of the native crystal have been collected.

  8. Immunohistochemical localization of glutathione S-transferase-pi in human colorectal polyps

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To investigate the distribution of the placental form of glutathione-S-transferase (GST) in colon polyps in order to evaluate the role of GST-pi in these tissues. METHODS: Sixteen polyp tissues removed at colon- oscopy were examined. Tissues were investigated his- tologicaUy and ultrastructurally. GST-pi expression was also analysed immunohistochemically, using peroxidase anti-peroxidase (PAP) method and immunogold label- ling method, for light and electron microscope respec- tively. RESULTS: All polyp tissues examined were adenoma of low, mild and high- grade dysplasia as shown in the histopathological reports. Nevertheless, the examina- tion of the above specimens with electron microscope revealed that 3 of 9 adenoma of mild dysplasia had ultrastuctural features similar to high-grade dysplasia adenoma. GST-pi was variably expressed in adenoma, with the lowest relative levels occurring in low-grade adenoma and the highest levels found in high-grade adenoma. GST-pi was located mainly in undifferentiat- ed epithelial cells. GST-pi positive particles were found in the cytoplasm and especially in the nucleus adjacent to the nuclear membrane of these cells. CONCLUSION: The overexpression of GST-pi in mild- grade adenomas with significant subcellular changes and in the majority of high-grade dysplasia adenoma suggests that this might be related to the carcinogenetic proceeding. Immunohistochemical localization of GST-pi in combination with ultrastructural changes indicate that GST-pi might be a sensitive agent for the detection of preneoplastic transformations in adenoma.

  9. Glutathione S-transferase P1 ILE105Val polymorphism in occupationally exposed bladder cancer cases.

    Science.gov (United States)

    Kopps, Silke; Angeli-Greaves, Miriam; Blaszkewicz, Meinolf; Prager, Hans-Martin; Roemer, Hermann C; Lohlein, Dietrich; Weistenhofer, Wobbeke; Bolt, Hermann M; Golka, Klaus

    2008-01-01

    The genotype glutathione S-transferase P1 (GSTP1) influences the risk for bladder cancer among Chinese workers occupationally exposed to benzidine. Studies of Caucasian bladder cancer cases without known occupational exposures showed conflicting results. Research was thus conducted to define the role of GSTP1 genotypes in Caucasian bladder cancer cases with an occupational history of exposure to aromatic amines. DNA from 143 cases reported to the Industrial Professional Associations (Berufsgenossenschaften) in Germany from 1996 to 2004, who had contracted urothelial cancer due to occupational exposure, and 196 patients from one Department of Surgery in Dortmund, without known malignancy in their medical history, were genotyped using real-time polymerase chain reaction (PCR) (LightCycler) in relation to GSTP1 A1578G (Ile105Val) polymorphism. Among the subjects with bladder cancer, 46% presented the AA genotype, 39% the AG genotype, and 15% the GG genotype. In the surgical (noncancer) control group analyzed, 42% presented the AA genotype, 42% the AG genotype, and 16% the GG genotype. A subgroup of bladder cancer cases, represented by 46 painters, showed a distribution of 41% of the AA genotype, 48% of the AG genotype, and 11% of the GG genotype. Data indicated that in Caucasians exposed to aromatic amines the GSTP1 A1578G polymorphism did not appear to play a significant role as a predisposing factor for bladder cancer incidence.

  10. Purification and characterization of a glutathione S-transferase from Mucor mucedo.

    Science.gov (United States)

    Hamed, Ragaa R; Abu-Shady, Mohamed R; El-Beih, Fawkia M; Abdalla, Abdel-Monem A; Afifi, Ola M

    2005-01-01

    An intracellular glutathione transferase was purified to homogenity from the fungus, Mucor mucedo, using DEAE-cellulose ion-exchange and glutathione affinity chromatography. Gel filtration chromatography and SDS-PAGE revealed that the purified GST is a homodimer with approximate native and subunit molecular mass of 53 kDa and 23.4 kDa, respectively. The enzyme has a pI value of 4.8, a pH optimum at pH 8.0 and apparent activation energy (Ea) of 1.42 kcal mol(-1). The purified GST acts readily on CDNB with almost negligible peroxidase activity and the activity was inhibited by Cibacron Blue (IC50 0.252 microM) and hematin (IC50 3.55 microM). M. mucedo GST displayed a non-Michaelian behavior. At low (0.1-0.3 mM) and high (0.3-2 mM) substrate concentration, Km (GSH) was calculated to be 0.179 and 0.65 mM, whereas Km(CDNB) was 0.531 and 11 mM and k(cat) was 39.8 and 552 s(-1), respectively. The enzyme showed apparent pKa values of 6-6.5 and 8.0. PMID:16209109

  11. Glutathione S-Transferase Ω 1 variation does not influence age at onset of Huntington's disease

    Directory of Open Access Journals (Sweden)

    Saft Carsten

    2004-03-01

    Full Text Available Abstract Background Huntington's disease (HD is a fully penetrant, autosomal dominantly inherited disorder associated with abnormal expansions of a stretch of perfect CAG repeats in the 5' part of the IT15 gene. The number of repeat units is highly predictive for the age at onset (AO of the disorder. But AO is only modestly correlated with repeat length when intermediate HD expansions are considered. Circumstantial evidence suggests that additional features of the HD course are based on genetic traits. Therefore, it may be possible to investigate the genetic background of HD, i.e. to map the loci underlying the development and progression of the disease. Recently an association of Glutathione S-Transferase Ω 1 (GSTO1 and possibly of GSTO2 with AO was demonstrated for, both, Alzheimer's (AD and Parkinson's disease (PD. Methods We have genotyped the polymorphisms rs4925 GSTO1 and rs2297235 GSTO2 in 232 patients with HD and 228 controls. Results After genotyping GSTO1 and GSTO2 polymorphisms, firstly there was no statistically significant difference in AO for HD patients, as well as secondly for HD patients vs. controls concerning, both, genotype and allele frequencies, respectively. Conclusion The GSTO1 and GSTO2 genes flanked by the investigated polymorphisms are not comprised in a primary candidate region influencing AO in HD.

  12. Septins guide microtubule protrusions induced by actin-depolymerizing toxins like Clostridium difficile transferase (CDT).

    Science.gov (United States)

    Nölke, Thilo; Schwan, Carsten; Lehmann, Friederike; Østevold, Kristine; Pertz, Olivier; Aktories, Klaus

    2016-07-12

    Hypervirulent Clostridium difficile strains, which are associated with increased morbidity and mortality, produce the actin-ADP ribosylating toxin Clostridium difficile transferase (CDT). CDT depolymerizes actin, causes formation of microtubule-based protrusions, and increases pathogen adherence. Here, we show that septins (SEPT) are essential for CDT-induced protrusion formation. SEPT2, -6, -7, and -9 accumulate at predetermined protrusion sites and form collar-like structures at the base of protrusions. The septin inhibitor forchlorfenuron or knockdown of septins inhibits protrusion formation. At protrusion sites, septins colocalize with the GTPase Cdc42 (cell division control protein 42) and its effector Borg (binder of Rho GTPases), which act as up-stream regulators of septin polymerization. Precipitation and surface plasmon resonance studies revealed high-affinity binding of septins to the microtubule plus-end tracking protein EB1, thereby guiding incoming microtubules. The data suggest that CDT usurps conserved regulatory principles involved in microtubule-membrane interaction, depending on septins, Cdc42, Borgs, and restructuring of the actin cytoskeleton. PMID:27339141

  13. Genetic Variations of Glutathione S-Transferase Influence on Blood Cadmium Concentration

    Directory of Open Access Journals (Sweden)

    Nitchaphat Khansakorn

    2012-01-01

    Full Text Available The glutathione S-transferases (GSTs are involved in biotransformation and detoxification of cadmium (Cd. Genetic polymorphisms in these genes may lead to interindividual variation in Cd susceptibility. The objective of this study was to assess the association of GSTs (GSTT1, GSTM1, and GSTP1 Val105Ile polymorphisms with blood Cd concentrations in a nonoccupationally exposed population. The 370 blood samples were analyzed for Cd concentration and polymorphisms in GSTs genes. Geometric mean of blood Cd among this population was 0.46±0.02 μg/L (with 95% CI; 0.43–0.49 μg/L. Blood Cd concentrations in subjects carrying GSTP1 Val/Val genotype were significantly higher than those with Ile/Ile and Ile/Val genotypes. No significant differences in blood Cd concentrations among individual with gene deletions of GSTT1 and GSTM1 were observed. GSTP1/GSTT1 and GSTP1/GSTM1 combinations showed significantly associated with increase in blood Cd levels. This study indicated that polymorphisms of GSTP1 combined with GSTT1 and/or GSTM1 deletion are likely to influence on individual susceptibility to cadmium toxicity.

  14. Expression profiling of selected glutathione transferase genes in Zea mays (L. seedlings infested with cereal aphids.

    Directory of Open Access Journals (Sweden)

    Hubert Sytykiewicz

    Full Text Available The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24 in the tissues of two maize (Zea mays L. varieties (relatively resistant Ambrozja and susceptible Tasty Sweet that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L. or monophagous grain aphid (Sitobion avenae L.. Simultaneously, insect-triggered generation of superoxide anion radicals (O2•- in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23 or 24 hpi (gst1, gst18 and gst24 compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

  15. Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype. PMID:25365518

  16. Glutathione-S-transferases in lung and sputum specimens, effects of smoking and COPD severity

    Directory of Open Access Journals (Sweden)

    Merikallio Heta

    2008-12-01

    Full Text Available Abstract Background Oxidative stress plays a potential role in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD. Glutathione S-transferases (GSTs detoxify toxic compounds in tobacco smoke via glutathione-dependent mechanisms. Little is known about the regulation and expression of GSTs in COPD lung and their presence in airway secretions. Methods GST alpha, pi and mu were investigated by immunohistochemistry in 72 lung tissue specimens and by Western analysis in total lung homogenates and induced sputum supernatants from non-smokers, smokers and patients with variable stages of COPD severity. Results GST alpha was expressed mainly in the airway epithelium. The percentage of GST alpha positive epithelial cells was lower in the central airways of patients with very severe (Stage IV COPD compared to mild/moderate COPD (p = 0.02. GST alpha by Western analysis was higher in the total lung homogenates in mild/moderate COPD compared to cases of very severe disease (p Conclusion This study indicates the presence of GST alpha and pi especially in the epithelium and sputum supernatants in mild/moderate COPD and low expression of GST alpha in the epithelium in cases of very severe COPD. The presence of GSTs in the airway secretions points to their potential protective role both as intracellular and extracellular mediators in human lung.

  17. Erythrocyte glutathione transferase: a general probe for chemical contaminations in mammals

    Science.gov (United States)

    Bocedi, A; Fabrini, R; Lai, O; Alfieri, L; Roncoroni, C; Noce, A; Pedersen, JZ; Ricci, G

    2016-01-01

    Glutathione transferases (GSTs) are enzymes devoted to the protection of cells against many different toxins. In erythrocytes, the isoenzyme (e-GST) mainly present is GSTP1-1, which is overexpressed in humans in case of increased blood toxicity, as it occurs in nephrophatic patients or in healthy subjects living in polluted areas. The present study explores the possibility that e-GST may be used as an innovative and highly sensitive biomarker of blood toxicity also for other mammals. All distinct e-GSTs from humans, Bos taurus (cow), Sus scrofa (pig), Capra hircus (goat), Equus caballus (horse), Equus asinus (donkey) and Ovis aries (sheep), show very similar amino acid sequences, identical kinetics and stability properties. Reference values for e-GST in all these mammals reared in controlled farms span from 3.5±0.2 U/gHb in the pig to 17.0±0.9 U/gHb in goat; such activity levels can easily be determined with high precision using only a few microliters of whole blood and a simple spectrophotometric assay. Possibly disturbing factors have been examined to avoid artifact determinations. This study provides the basis for future screening studies to verify if animals have been exposed to toxicologic insults. Preliminary data on cows reared in polluted areas show increased expression of e-GST, which parallels the results found for humans. PMID:27551520

  18. Immunoprophylactic potential of filarial glutathione-s-transferase in lymphatic filariaisis

    Institute of Scientific and Technical Information of China (English)

    BalM; MandalN; AcharyKG; DasMK; KarSK

    2011-01-01

    Objective:To elucidates the immunoprophylactic potential of glutathion-s-transferase (GST) from cattle filarial parasite Setaria digitata (S. digitata) against lymphatic filariasis. Methods:GST was purified through affinity chromatography (SdGST) and chacterized by SDS-PAGE and Nano-LC MS/MS analysis. Antibody isotypes to SdGST were measured by ELISA. Antibody dependant cellular cytotoxicity (ADCC) was performed in vitro using sera from immunized animals and immune individuals. T-cell proliferation and cytokine response to SdGST in different groups of filariasis were measured. Immunoprophylactic potential of SdGST was evaluate in animal model. Results: SdGST exhibited 30-fold enhancement of enzyme activity over crude parasitic extract. It was found to be 26 kDa by SDS-PAGE. Nano LC-MS/MS analysis followed by blast search showed 100%homology with Dirofilaria immitis (D. immitis) and only 43%with Homo sapiens (H. sapiens). Immunoblotting analysis showed putatively immune individuals carry significant level of antibodies to SdGST as compared with microfilaraemics. Immunized sera and sera endemic normal could neutralize the enzymatic activity of SdGST and inducing in vitro cytotoxicity of microfilariae. Peripheral blood mononuclear cells (PBMC) from endemic normals upon stimulation with SdGST showed a mixed type of Th1/Th2 response. SdGST immunization clear microfilariae from circulation in S. digitata implanted mastomys. Conclusions:The heterologous GST could be potentially developed as a vaccine candidate against lymphatic filarial parasite.

  19. Identification of Small-Molecule Frequent Hitters of Glutathione S-Transferase-Glutathione Interaction.

    Science.gov (United States)

    Brenke, Jara K; Salmina, Elena S; Ringelstetter, Larissa; Dornauer, Scarlett; Kuzikov, Maria; Rothenaigner, Ina; Schorpp, Kenji; Giehler, Fabian; Gopalakrishnan, Jay; Kieser, Arnd; Gul, Sheraz; Tetko, Igor V; Hadian, Kamyar

    2016-07-01

    In high-throughput screening (HTS) campaigns, the binding of glutathione S-transferase (GST) to glutathione (GSH) is used for detection of GST-tagged proteins in protein-protein interactions or enzyme assays. However, many false-positives, so-called frequent hitters (FH), arise that either prevent GST/GSH interaction or interfere with assay signal generation or detection. To identify GST-FH compounds, we analyzed the data of five independent AlphaScreen-based screening campaigns to classify compounds that inhibit the GST/GSH interaction. We identified 53 compounds affecting GST/GSH binding but not influencing His-tag/Ni(2+)-NTA interaction and general AlphaScreen signals. The structures of these 53 experimentally identified GST-FHs were analyzed in chemoinformatic studies to categorize substructural features that promote interference with GST/GSH binding. Here, we confirmed several existing chemoinformatic filters and more importantly extended them as well as added novel filters that specify compounds with anti-GST/GSH activity. Selected compounds were also tested using different antibody-based GST detection technologies and exhibited no interference clearly demonstrating specificity toward their GST/GSH interaction. Thus, these newly described GST-FH will further contribute to the identification of FH compounds containing promiscuous substructures. The developed filters were uploaded to the OCHEM website (http://ochem.eu) and are publicly accessible for analysis of future HTS results. PMID:27044684

  20. Purification and characterization of a glutathione S-transferase from Mucor mucedo.

    Science.gov (United States)

    Hamed, Ragaa R; Abu-Shady, Mohamed R; El-Beih, Fawkia M; Abdalla, Abdel-Monem A; Afifi, Ola M

    2005-01-01

    An intracellular glutathione transferase was purified to homogenity from the fungus, Mucor mucedo, using DEAE-cellulose ion-exchange and glutathione affinity chromatography. Gel filtration chromatography and SDS-PAGE revealed that the purified GST is a homodimer with approximate native and subunit molecular mass of 53 kDa and 23.4 kDa, respectively. The enzyme has a pI value of 4.8, a pH optimum at pH 8.0 and apparent activation energy (Ea) of 1.42 kcal mol(-1). The purified GST acts readily on CDNB with almost negligible peroxidase activity and the activity was inhibited by Cibacron Blue (IC50 0.252 microM) and hematin (IC50 3.55 microM). M. mucedo GST displayed a non-Michaelian behavior. At low (0.1-0.3 mM) and high (0.3-2 mM) substrate concentration, Km (GSH) was calculated to be 0.179 and 0.65 mM, whereas Km(CDNB) was 0.531 and 11 mM and k(cat) was 39.8 and 552 s(-1), respectively. The enzyme showed apparent pKa values of 6-6.5 and 8.0.

  1. Cefadroxil potency as cancer co-therapy candidate by glutathione s-transferase mechanism

    Directory of Open Access Journals (Sweden)

    Tri Yuliani

    2013-03-01

    Full Text Available Background: Glutathione S-transferases (GSTs havean important role in the detoxification of electrophiles,such as some anticancer drugs. Compounds with phenolicand/or α,b-unsaturated carbonyl group have been knownas GSTs inhibitor in vitro. Cefadroxil in vitro decreasedGST-Pi activity but not GSTs in rat kidney cytosol.GST inhibitor in a specific organ and of a specific classis needed for safety in cancer chemotherapy. The studyaims to observe the effect of cefadroxil on GSTs in vivoin rat kidney cytosol and then compare it to those seenfor liver, lung, and spleen in vivo.Methods: Cefadroxil was given twice a day byforcefeeding for five days. Rat kidney cytosol was thenprepared and its protein concentration was determined.Cytosolic total GST, GST-Mu and GST-Pi activitieswere monitored by a continuous spectrophotometricmethod using the following substrates: 1-chloro,2,4-dinitrobenzene (CDNB (non-specific substrate,1,2-dichloro-4-nitrobenzene (DCNB for GST-Mu, andethacrynic acid (EA for GST-Pi.Results: The data showed that cefadroxil significantlyincreased the activity of GSTs, GST-Mu, and GSTPiin rat kidney cytosol (8.75%, 47.81%, and 6.67%respectively.Conclusion: Cefadroxil did not inhibit GSTs, GST-Mu,and GST-Pi in rat kidney in vivo indicating that it doesnot inhibit chemotherapy detoxification by GSTs, GSTMu,and GST-Pi in normal kidney cells.

  2. Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1

    Energy Technology Data Exchange (ETDEWEB)

    Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling; Gorman, Michael A.; Morton, Craig J.; Pyke, James; McConville, Malcolm J.; Bieri, Michael; Mok, Yee-Foong; Robin, Charles; Gooley, Paul R.; Parker, Michael W.; Batterham, Philip (SVIMR-A); (Melbourne)

    2010-06-14

    GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model of the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. We also show that the ancestral GSTD1 is likely to have possessed DDT dehydrochlorinase activity because both GSTD1 from D. melanogaster and its sibling species, Drosophila simulans, have this activity.

  3. Evaluation of gamma gluthamyl transferase and uric acid levels in arsenic exposed subject

    Directory of Open Access Journals (Sweden)

    Ceylan Bal

    2015-06-01

    Full Text Available Objective: Arsenic is a metal with a widespread industrial usage and causing oxidative stress. Studies shows serum uric acid and gamma gluthamyl transferase (GGT levels are increasing in oxidative stress. The aim of this study is to evaluate the effect of arsenic exposure on serum uric acid and GGT levels. Methods: 500 patients who refer to Ankara Occupational Disease Hospital between 2010 to 2014 for periodic examination and urinary arsenic, serum uric acid and serum GGT levels assessed are included in this study. 268 patients with urinary arsenic levels over 35μg/L are defined as exposed and below 35μg/L are controls. Results: Data of 500 patients were analysed. 268 of them had high urine arsenic levels and 232 had normal urine arsenic levels. In the high urine arsenic level group the median serum uric acid level was 5.4 (2.60-7.20 and median serum GGT level was 27 (10-51 in the other group with normal urine arsenic levels the median serum uric acid level was 4.9 (2.5-7 and median serum GGT level was 22 (10-52. The difference between two groups was statistically significant (p value: 0.002 and <0.001 respectively Conclusion: Arsenic exposure may be associated with hyperuricemia and high levels of GGT and with prospective studies the causal relationship between arsenic exposure and hyperuricemia and GGT can be revealed.

  4. Transcriptional Responses of Glutathione Transferase Genes in Ruditapes philippinarum Exposed to Microcystin-LR

    Directory of Open Access Journals (Sweden)

    Bruno Reis

    2015-04-01

    Full Text Available Glutathione Transferases (GSTs are phase II detoxification enzymes known to be involved in the molecular response against microcystins (MCs induced toxicity. However, the individual role of the several GST isoforms in the MC detoxification process is still unknown. In this study, the time-dependent changes on gene expression of several GST isoforms (pi, mu, sigma 1, sigma 2 in parallel with enzymatic activity of total GST were investigated in gills and hepatopancreas of the bivalve Ruditapes philippinarum exposed to pure MC-LR (10 and 100 µg/L. No significant changes in GST enzyme activities were found on both organs. In contrast, MC-LR affected the transcriptional activities of these detoxification enzymes both in gills and hepatopancreas. GST transcriptional changes in gills promoted by MC-LR were characterized by an early (12 h induction of mu and sigma 1 transcripts. On the other hand, the GST transcriptional changes in hepatopancreas were characterized by a later induction (48 h of mu transcript, but also by an early inhibition (6 h of the four transcripts. The different transcription patterns obtained for the tested GST isoforms in this study highlight the potential divergent physiological roles played by these isoenzymes during the detoxification of MC-LR.

  5. Glutathione S-transferase P influences redox and migration pathways in bone marrow.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    Full Text Available To interrogate why redox homeostasis and glutathione S-transferase P (GSTP are important in regulating bone marrow cell proliferation and migration, we isolated crude bone marrow, lineage negative and bone marrow derived-dendritic cells (BMDDCs from both wild type (WT and knockout (Gstp1/p2(-/- mice. Comparison of the two strains showed distinct thiol expression patterns. WT had higher baseline and reactive oxygen species-induced levels of S-glutathionylated proteins, some of which (sarco-endoplasmic reticulum Ca2(+-ATPase regulate Ca(2+ fluxes and subsequently influence proliferation and migration. Redox status is also a crucial determinant in the regulation of the chemokine system. CXCL12 chemotactic response was stronger in WT cells, with commensurate alterations in plasma membrane polarization/permeability and intracellular calcium fluxes; activities of the downstream kinases, ERK and Akt were also higher in WT. In addition, expression levels of the chemokine receptor CXCR4 and its associated phosphatase, SHP-2, were higher in WT. Inhibition of CXCR4 or SHP2 decreased the extent of CXCL12-induced migration in WT BMDDCs. The differential surface densities of CXCR4, SHP-2 and inositol trisphosphate receptor in WT and Gstp1/p2(-/- cells correlated with the differential CXCR4 functional activities, as measured by the extent of chemokine-induced directional migration and differences in intracellular signaling. These observed differences contribute to our understanding of how genetic ablation of GSTP causes different levels of myeloproliferation and migration [corrected

  6. Prevalence of glutathione S-transferase gene deletions and their effect on sickle cell patients

    Directory of Open Access Journals (Sweden)

    Pandey Sanjay

    2012-01-01

    Full Text Available BACKGROUND: Glutathione S-transferase gene deletions are known detoxification agents and cause oxidative damage. Due to the different pathophysiology of anemia in thalassemia and sickle cell disease, there are significant differences in the pathophysiology of iron overload and iron-related complications in these disorders. OBJECTIVE: The aim of this study was to estimate the frequency of the GSTM1 and GSTT1 genotypes in sickle cell disease patients and their effect on iron status. METHODS: Forty sickle cell anemia and sixty sickle ß-thalassemia patients and 100 controls were evaluated to determine the frequency of GST gene deletions. Complete blood counts were performed by an automated cell analyzer. Hemoglobin F, hemoglobin A, hemoglobin A2 and hemoglobin S were measured and diagnosis of patients was achieved by high performance liquid chromatography with DNA extraction by the phenol-chloroform method. The GST null genotype was determined using multiplex polymerase chain reaction and serum ferritin was measured using an ELISA kit. Statistical analysis was by EpiInfo and GraphPad statistics software. RESULTS: An increased frequency of the GSTT1 null genotype (p-value = 0.05 was seen in the patients. The mean serum ferritin level was higher in patients with the GST genotypes than in controls; this was statistically significant for all genotypes except GSTM1, however the higher levels of serum ferritin were due to blood transfusions in patients. CONCLUSION: GST deletions do not play a direct role in iron overload of sickle cell patients.

  7. Trichinella spiralis: low vaccine potential of glutathione S-transferase against infections in mice.

    Science.gov (United States)

    Li, Ling Ge; Wang, Zhong Quan; Liu, Ruo Dan; Yang, Xuan; Liu, Li Na; Sun, Ge Ge; Jiang, Peng; Zhang, Xi; Zhang, Gong Yuan; Cui, Jing

    2015-06-01

    We have previously reported that Trichinella spiralis glutathione-S-transferase (TsGST) gene is an up-regulated gene in intestinal infective larvae (IIL) compared to muscle larvae (ML). In this study, the TsGST gene was cloned, and recombinant TsGST (rTsGST) was produced. Anti-rTsGST serum recognized the native TsGST by Western blotting in crude antigens of ML, adult worm (AW) and newborn larvae (NBL) of T. spiralis, but not in ML excretory-secretory (ES) antigens. Expression of TsGST was observed in all different developmental stages (IIL, AW, NBL and ML). An immunolocalization analysis identified TsGST in the cuticle, stichosome and genital primordium of the parasite. The rTsGST had GST enzymatic activity. After a challenge infection with T. spiralis larvae, mice immunized with rTsGST displayed a 35.71% reduction in adult worms and a 38.55% reduction in muscle larvae. The vaccination of mice with rTsGST induced the Th1/Th2-mixed type of immune response with Th2 predominant (high levels of IgG1) and partial protective immunity against T. spiralis infection. PMID:25757368

  8. Optical biosensor consisting of glutathione-S-transferase for detection of captan.

    Science.gov (United States)

    Choi, Jeong-Woo; Kim, Young-Kee; Song, Sun-Young; Lee, In-ho; Lee, Won-Hong

    2003-10-15

    The optical biosensor consisting of a glutathione-S-transferase (GST)-immobilized gel film was developed to detect captan in contaminated water. The sensing scheme was based on the decrease of yellow product, s-(2,4-dinitrobenzene) glutathione, produced from substrates, 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH), due to the inhibition of GST reaction by captan. Absorbance of the product as the output of enzyme reaction was detected and the light was guided through the optical fibers. The enzyme reactor of the sensor system was fabricated by the gel entrapment technique for the immobilized GST film. The immobilized GST had the maximum activity at pH 6.5. The optimal concentrations of substrates were determined with 1 mM for both of CDNB and GSH. The optimum concentration of enzyme was also determined with 100 microg/ml. The activity of immobilized enzyme was fairly sustained during 30 days. The proposed biosensor could successfully detect the captan up to 2 ppm and the response time to steady signal was about 15 min.

  9. Induction of Epoxide Hydrolase, Glucuronosyl Transferase, and Sulfotransferase by Phenethyl Isothiocyanate in Male Wistar Albino Rats

    Directory of Open Access Journals (Sweden)

    Ahmad Faizal Abdull Razis

    2014-01-01

    Full Text Available Phenethyl isothiocyanate (PEITC is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin. The isothiocyanate is converted from the glucosinolate by intestinal microflora or when contacted with myrosinase during the chopping and mastication of the vegetable. PEITC manifested protection against chemically-induced cancers in various tissues. A potential mechanism of chemoprevention is by modulating the metabolism of carcinogens so as to promote deactivation. The principal objective of this study was to investigate in rats the effect of PEITC on carcinogen-metabolising enzyme systems such as sulfotransferase (SULT, N-acetyltransferase (NAT, glucuronosyl transferase (UDP, and epoxide hydrolase (EH following exposure to low doses that simulate human dietary intake. Rats were fed for 2 weeks diets supplemented with PEITC at 0.06 µmol/g (low dose, i.e., dietary intake, 0.6 µmol/g (medium dose, and 6.0 µmol/g (high dose, and the enzymes were monitored in rat liver. At the Low dose, no induction of the SULT, NAT, and EH was noted, whereas UDP level was elevated. At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed. It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

  10. Gamma-Glutamyl Transferase Levels in Patients with Acute Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Nurbanu Gurbuzer

    2014-01-01

    Full Text Available Objective. The aim of this study was to investigate the relationship between gamma-glutamyl transferase (GGT levels, cerebrovascular risk factors, and distribution of cerebral infarct areas in patients with acute ischemic stroke (AIS. Patients and Methods. Sixty patients with AIS and 44 controls who had not cerebrovascular disease were included in the study. The patients were divided into four groups according to the location of the infarct area and evaluated as for GGT levels and the presence of diabetes mellitus (DM, hypertension (HT, and hyperlipidemia (HL. Results. The frequency of DM, HT, and HL and gender distributions were similar. The mean GGT levels were significantly higher in patients with AIS and those with relatively larger areas of infarction (P<0.05. Increased mean GGT levels were found in the subgroup with hypertension, higher LDL-cholesterol, and triglyceride levels among cases with AIS (P<0.05. Conclusion. Higher GGT levels in AIS patients reinforce the relationship of GGT with inflammation and oxidative stress. The observation of higher GGT levels in patients with relatively larger areas of infarction is indicative of a positive correlation between increases in infarct areas and elevated GGT levels.

  11. Measurement of mouse liver glutathione S-transferase activity by the integrated method

    Institute of Scientific and Technical Information of China (English)

    廖飞; 李甲初; 康格非; 曾昭淳; 左渝萍

    2003-01-01

    Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transferase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twenty-fold above the others and taking maximum product absorbance Am as parameter while Km as constant, Vm/Km was obtained by nonlinear fitting of GST reaction curve to the integrated Michaelis-Menten equation ln [Am/(Am-Ai)]+Ai/(ε×Km)=(Vm/Km)×ti (1). Results: Vm/Km for GST showed slight dependence on initial substrate concentration and data range, but it was resistant to background absorbance, error in reaction origin and small deviation in presetting Km. Vm/Km was proportional to the amount of GST with upper limit higher than that by initial rate. There was close correlation between Vm/Km and initial rate of the same GST. Consistent results were obtained by this integrated method and classical initial rate method for the measurement of mouse liver GST. Conclusion: With the concentration of one substrate twenty-fold above the others, this integrated method was reliable to measure the activity of enzyme on two substrates, and substrate concentration of the lower one close to its apparent Km was able to be used.

  12. Characterization and evolutionary implications of the triad Asp-Xxx-Glu in group II phosphopantetheinyl transferases.

    Science.gov (United States)

    Wang, Yue-Yue; Li, Yu-Dong; Liu, Jian-Bo; Ran, Xin-Xin; Guo, Yuan-Yang; Ren, Ni-Ni; Chen, Xin; Jiang, Hui; Li, Yong-Quan

    2014-01-01

    Phosphopantetheinyl transferases (PPTases), which play an essential role in both primary and secondary metabolism, are magnesium binding enzymes. In this study, we characterized the magnesium binding residues of all known group II PPTases by biochemical and evolutionary analysis. Our results suggested that group II PPTases could be classified into two subgroups, two-magnesium-binding-residue-PPTases containing the triad Asp-Xxx-Glu and three-magnesium-binding-residue-PPTases containing the triad Asp-Glu-Glu. Mutations of two three-magnesium-binding-residue-PPTases and one two-magnesium-binding-residue-PPTase indicate that the first and the third residues in the triads are essential to activities; the second residues in the triads are non-essential. Although variations of the second residues in the triad Asp-Xxx-Glu exist throughout the whole phylogenetic tree, the second residues are conserved in animals, plants, algae, and most prokaryotes, respectively. Evolutionary analysis suggests that: the animal group II PPTases may originate from one common ancestor; the plant two-magnesium-binding-residue-PPTases may originate from one common ancestor; the plant three-magnesium-binding-residue-PPTases may derive from horizontal gene transfer from prokaryotes.

  13. Effects of glutathione S-transferase M1 and T1 deletions on epilepsy risk among a Tunisian population.

    Science.gov (United States)

    Chbili, Chahra; B'chir, Fatma; Ben Fredj, Maha; Saguem, Bochra-Nourhène; Ben Amor, Sana; Ben Ammou, Sofiene; Saguem, Saad

    2014-09-01

    Glutathione-S-transferases enzymes are involved in the detoxification of several endogenous and exogenous substances. In this present study, we evaluated the effects of two glutathione-S-transferase polymorphisms, (GSTM1 and GSTT1) on epilepsy risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 98 patients with epilepsy, using a polymerase chain reaction (PCR). Odds ratio (ORs) was used for analyzing results. The study results demonstrated that individuals with the GSTM1 null genotype were at an increased risk of developing epilepsy [OR=3.80, 95% confidence interval (CI) (2.15-4.78)], whereas no significant effects were observed between individuals with GSTT1 null genotype and epilepsy risk [OR=1.15, 95% CI (0.62-2.12)]. These genotyping finding revealed that the absence of GSTM1 activity could be contributor factor for the development of epilepsy disease.

  14. Action of glycosyl transferases upon "Bombay" (Oh) erythrocytes. Conversion to cells showing blood-group H and A specificities.

    Science.gov (United States)

    Schenkel-Brunner, H; Prohaska, R; Tuppy, H

    1975-08-15

    Individuals of the rare "Bombay" (Oh) blood-group phenotype lacking, due to a genetic defect, the alpha(1-2)fucosyl transferase, which is responsible for converting blood-group H precursor substances to H-specific structures. Treatment with GDP-fucose and alpha(1-2)fucosyl transferase prepared from gastric mucosa of O individuals to transform native or ficin-treated "Bombay" erythrocytes into cells phenotypically resembling O cells. The transformation was achieved, however, after prior incubation of the "Bombay" erythrocytes with neuraminidase, indicating that blood-group H precursor molecules on the surface of these cells are masked by sialyl residues. Blood-group A specificity was conferred upon neuraminidase-treated "Bombay" cells by enzymatic transfer of alpha-N-acetylgalactosamine residues, in addition to alpha-fucose residues.

  15. Distribution of glutathione S-transferase isoenzymes in human kidney: basis for possible markers of renal injury.

    OpenAIRE

    Harrison, D J; Kharbanda, R; Cunningham, D S; McLellan, L I; Hayes, J. D.

    1989-01-01

    To determine whether the tissue distribution of glutathione S-transferase (GST) isoenzymes could define the precise nature of renal injury, 13 adult kidneys were studied, using specific antibodies raised against purified isoenzymes. Basic GST stained strongly proximal convoluted tubules and some medullary tubules; acidic GST stained strongly distal convoluted tubules and medullary tubules; neutral GST stained similarly to acidic GST, but weaker, and microsomal GST stained glomerular and inter...

  16. Effect of cadmium on glutathione S-transferase and metallothionein gene expression in coho salmon liver, gill and olfactory tissues

    OpenAIRE

    Espinoza, Herbert M.; Williams, Chase R.; Gallagher, Evan P.

    2011-01-01

    The glutathione S-transferases (GSTs) are a multifunctional family of phase II enzymes that detoxify a variety of environmental chemicals, reactive intermediates, and secondary products of oxidative damage. GST mRNA expression and catalytic activity have been used as biomarkers of exposure to environmental chemicals. However, factors such as species differences in induction, partial analyses of multiple GST isoforms, and lack of understanding of fish GST gene regulation, have confounded the u...

  17. Mimicking Insect Communication: Release and Detection of Pheromone, Biosynthesized by an Alcohol Acetyl Transferase Immobilized in a Microreactor

    OpenAIRE

    Lourdes Muñoz; Nikolay Dimov; Gerard Carot-Sans; Bula, Wojciech P.; Angel Guerrero; Gardeniers, Han J. G. E.

    2012-01-01

    Infochemical production, release and detection of (Z,E)-9,11-tetradecadienyl acetate, the major component of the pheromone of the moth Spodoptera littoralis is achieved in a novel microfluidic system, designed to mimic the final step of the pheromone biosynthesis by immobilized recombinant alcohol acetyl transferase. The microfluidic system is part of an "artificial gland", i.e. a chemoemitter that comprises a microreactor connected to a microevaporator and is able to produce a...

  18. 23S rRNA nucleotides in the peptidyl transferase center are essential for tryptophanase operon induction.

    Science.gov (United States)

    Yang, Rui; Cruz-Vera, Luis R; Yanofsky, Charles

    2009-06-01

    Distinct features of the ribosomal peptide exit tunnel are known to be essential for recognition of specific amino acids of a nascent peptidyl-tRNA. Thus, a tryptophan residue at position 12 of the peptidyl-tRNA TnaC-tRNA(Pro) leads to the creation of a free tryptophan binding site within the ribosome at which bound tryptophan inhibits normal ribosome functions. The ribosomal processes that are inhibited are hydrolysis of TnaC-tRNA(Pro) by release factor 2 and peptidyl transfer of TnaC of TnaC-tRNA(Pro) to puromycin. These events are normally performed in the ribosomal peptidyl transferase center. In the present study, changes of 23S rRNA nucleotides in the 2585 region of the peptidyl transferase center, G2583A and U2584C, were observed to reduce maximum induction of tna operon expression by tryptophan in vivo without affecting the concentration of tryptophan necessary to obtain 50% induction. The growth rate of strains with ribosomes with either of these changes was not altered appreciably. In vitro analyses with mutant ribosomes with these changes showed that tryptophan was not as efficient in protecting TnaC-tRNA(Pro) from puromycin action as wild-type ribosomes. However, added tryptophan did prevent sparsomycin action as it normally does with wild-type ribosomes. These findings suggest that these two mutational changes act by reducing the ability of ribosome-bound tryptophan to inhibit peptidyl transferase activity rather than by reducing the ability of the ribosome to bind tryptophan. Thus, the present study identifies specific nucleotides within the ribosomal peptidyl transferase center that appear to be essential for effective tryptophan induction of tna operon expression. PMID:19329641

  19. Molecular characterization of two galactosemia mutations: correlation of mutations with highly conserved domains in galactose-1-phosphate uridyl transferase.

    OpenAIRE

    Reichardt, J K; Packman, S; Woo, S L

    1991-01-01

    Galactosemia is an autosomal recessive disorder of human galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (GALT). The molecular basis of this disorder is at present not well understood. We report here two missense mutations which result in low or undetectable enzymatic activity. First, we identified at nucleotide 591 a transition which substitutes glutamine 188 by arginine. The mutated glutamine is not only highly conserved in evolution (conserv...

  20. Dual Localization of Glutathione S-Transferase in the Cytosol and Mitochondria: Implications in Oxidative Stress, Toxicity and Disease

    OpenAIRE

    Raza, Haider

    2011-01-01

    Glutathione (GSH) conjugating enzymes, glutathione S-transferases (GSTs) are present in different subcellular compartments including cytosol, mitochondria, endoplasmic reticulum, nucleus and plasma membrane. The regulation and function of GSTs have implications in cell growth, oxidative stress, as well as in disease progression and prevention. Of the several mitochondria localized forms, GSTK (GST kappa) is mitochondria-specific since it contains N-terminal canonical and cleavable mitochondri...

  1. Identification and Characterization of Seven Glutathione S-Transferase Genes from Citrus Red Mite, Panonychus citri (McGregor)

    OpenAIRE

    Liao, Chong-Yu; Zhang, Kun; Niu, Jin-Zhi; Ding, Tian-Bo; Zhong, Rui; Xia, Wen-Kai; Dou, Wei; Wang, Jin-Jun

    2013-01-01

    The citrus red mite, Panonychus citri (McGregor), is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs) genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed th...

  2. A fluorescent assay amenable to measuring production of beta-D-glucuronides produced from recombinant UDP-glycosyl transferase enzymes.

    Science.gov (United States)

    Trubetskoy, O V; Shaw, P M

    1999-05-01

    Beta-glucuronidase cleavage of 4-methylumbelliferyl beta-D-glucuronide generates the highly fluorescent compound, 4-methylumbelliferone. We show that other beta-D-glucuronide compounds act as competitors in this assay. The 4-methylumbelliferyl beta-D-glucuronide cleavage assay can easily be adapted to high throughput formats to detect the presence of beta-D glucuronides generated using recombinant glycosyl transferase preparations.

  3. Relationship between gamma-glutamyl transferase and glucose intolerance in first degree relatives of type 2 diabetics patients

    OpenAIRE

    Sassan Haghighi; Massoud Amini; Zahra Pournaghshband; Peyvand Amini; Silva Hovsepian

    2011-01-01

    Background: Considering that serum gamma-glutamyl transferase (GGT) activity could reflect several different processes relevant to diabetes pathogenesis and the increasing rate of type 2 diabetes worldwide, the aim of this study was to assess the association between serum GGT concentrations and glucose intolerance, in the first-degree relatives (FDR) of type 2 diabetic patients. Methods: In this descriptive study, 30-80 years old, non diabetic FDRs of type 2 diabetic patients were studie...

  4. Distinct and cooperative activities of HESO1 and URT1 nucleotidyl transferases in microRNA turnover in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Bin Tu

    2015-04-01

    Full Text Available 3' uridylation is increasingly recognized as a conserved RNA modification process associated with RNA turnover in eukaryotes. 2'-O-methylation on the 3' terminal ribose protects micro(miRNAs from 3' truncation and 3' uridylation in Arabidopsis. Previously, we identified HESO1 as the nucleotidyl transferase that uridylates most unmethylated miRNAs in vivo, but substantial 3' tailing of miRNAs still remains in heso1 loss-of-function mutants. In this study, we found that among nine other potential nucleotidyl transferases, UTP:RNA uridylyltransferase 1 (URT1 is the single most predominant nucleotidyl transferase that tails miRNAs. URT1 and HESO1 prefer substrates with different 3' end nucleotides in vitro and act cooperatively to tail different forms of the same miRNAs in vivo. Moreover, both HESO1 and URT1 exhibit nucleotidyl transferase activity on AGO1-bound miRNAs. Although these enzymes are able to add long tails to AGO1-bound miRNAs, the tailed miRNAs remain associated with AGO1. Moreover, tailing of AGO1-bound miRNA165/6 drastically reduces the slicing activity of AGO1-miR165/6, suggesting that tailing reduces miRNA activity. However, monouridylation of miR171a by URT1 endows the miRNA the ability to trigger the biogenesis of secondary siRNAs. Therefore, 3' tailing could affect the activities of miRNAs in addition to leading to miRNA degradation.

  5. Effect of trans-acting factor on rat glutathione S-transferase P1 gene transcription regulation in tumor cells

    Institute of Scientific and Technical Information of China (English)

    刘东远; 廖名湘; 左瑾; 方福德

    2002-01-01

    Objective To investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells. Methods The binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer Ⅰ (GPEI) and glutathione S-transferase P enhancer Ⅱ-1 (GPEⅡ-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment. Results Trans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPEⅡ-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver. Conclusion cGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

  6. An alternate pathway of arsenate resistance in E. coli mediated by the glutathione S-transferase GstB.

    Science.gov (United States)

    Chrysostomou, Constantine; Quandt, Erik M; Marshall, Nicholas M; Stone, Everett; Georgiou, George

    2015-03-20

    Microbial arsenate resistance is known to be conferred by specialized oxidoreductase enzymes termed arsenate reductases. We carried out a genetic selection on media supplemented with sodium arsenate for multicopy genes that can confer growth to E. coli mutant cells lacking the gene for arsenate reductase (E. coli ΔarsC). We found that overexpression of glutathione S-transferase B (GstB) complemented the ΔarsC allele and conferred growth on media containing up to 5 mM sodium arsenate. Interestingly, unlike wild type E. coli arsenate reductase, arsenate resistance via GstB was not dependent on reducing equivalents provided by glutaredoxins or a catalytic cysteine residue. Instead, two arginine residues, which presumably coordinate the arsenate substrate within the electrophilic binding site of GstB, were found to be critical for transferase activity. We provide biochemical evidence that GstB acts to directly reduce arsenate to arsenite with reduced glutathione (GSH) as the electron donor. Our results reveal a pathway for the detoxification of arsenate in bacteria that hinges on a previously undescribed function of a bacterial glutathione S-transferase.

  7. Neuroantibodies (NAB) in African-American Children: Associations with Gender, Glutathione-S-Transferase (GST)Pi Polymorphisms (SNP) and Heavy Metals

    Science.gov (United States)

    CONTACT (NAME ONLY): Hassan El-Fawal Abstract Details PRESENTATION TYPE: Platform or Poster CURRENT CATEGORY: Neurodegenerative Disease | Biomarkers | Neurotoxicity, Metals KEYWORDS: Autoantibodies, Glutathione-S-Transferase, DATE/TIME LAST MODIFIED: DATE/TIME SUBMITTED: Abs...

  8. Arylamine N-acetyl Transferase (NAT) in the blue secretion of Telescopium telescopium: xenobiotic metabolizing enzyme as a biomarker for detection of environmental pollution

    OpenAIRE

    Gorain, Bapi; Chakraborty, Sumon; Pal, Murari Mohan; Sarkar, Ratul; Samanta, Samir Kumar; Karmakar, Sanmoy; Sen, Tuhinadri

    2014-01-01

    Telescopium telescopium, a marine mollusc collected from Sundarban mangrove, belongs to the largest mollusca phylum in the world and exudes a blue secretion when stimulated mechanically. The blue secretion was found to metabolize (preferentially) para-amino benzoic acid, a substrate for N-acetyl transferase (NAT), thereby indicating acetyl transferase like activity of the secretion. Attempts were also made to characterise bioactive fraction of the blue secretion and to further use this as a b...

  9. Assignment of Biochemical Functions to Glycosyl Transferase Genes Which Are Essential for Biosynthesis of Exopolysaccharides in Sphingomonas Strain S88 and Rhizobium leguminosarum

    OpenAIRE

    Pollock, Thomas J.; van Workum, Wilbert A. T.; Thorne, Linda; Mikolajczak, Marcia J.; Yamazaki, Motohide; Kijne, Jan W.; Armentrout, Richard W.

    1998-01-01

    Glycosyl transferases which recognize identical substrates (nucleotide-sugars and lipid-linked carbohydrates) can substitute for one another in bacterial polysaccharide biosynthesis, even if the enzymes originate in different genera of bacteria. This substitution can be used to identify the substrate specificities of uncharacterized transferase genes. The spsK gene of Sphingomonas strain S88 and the pssDE genes of Rhizobium leguminosarum were identified as encoding glucuronosyl-(β1→4)-glucosy...

  10. Glutathione S-transferase P protects against cyclophosphamide-induced cardiotoxicity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Conklin, Daniel J., E-mail: dj.conklin@louisville.edu [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Haberzettl, Petra; Jagatheesan, Ganapathy; Baba, Shahid [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Merchant, Michael L. [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Division of Nephrology, Department of Medicine, University of Louisville, Louisville, KY 40292 (United States); Prough, Russell A. [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40292 (United States); Williams, Jessica D. [University of Cincinnati College of Medicine, Internal Medicine, Cincinnati, OH 45267 (United States); Prabhu, Sumanth D. [Division of Cardiovascular Disease, University of Alabama-Birmingham, Birmingham, AL 35294 (United States); Bhatnagar, Aruni [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40292 (United States)

    2015-06-01

    High-dose chemotherapy regimens using cyclophosphamide (CY) are frequently associated with cardiotoxicity that could lead to myocyte damage and congestive heart failure. However, the mechanisms regulating the cardiotoxic effects of CY remain unclear. Because CY is converted to an unsaturated aldehyde acrolein, a toxic, reactive CY metabolite that induces extensive protein modification and myocardial injury, we examined the role of glutathione S-transferase P (GSTP), an acrolein-metabolizing enzyme, in CY cardiotoxicity in wild-type (WT) and GSTP-null mice. Treatment with CY (100–300 mg/kg) increased plasma levels of creatine kinase-MB isoform (CK·MB) and heart-to-body weight ratio to a significantly greater extent in GSTP-null than WT mice. In addition to modest yet significant echocardiographic changes following acute CY-treatment, GSTP insufficiency was associated with greater phosphorylation of c-Jun and p38 as well as greater accumulation of albumin and protein–acrolein adducts in the heart. Mass spectrometric analysis revealed likely prominent modification of albumin, kallikrein-1-related peptidase, myoglobin and transgelin-2 by acrolein in the hearts of CY-treated mice. Treatment with acrolein (low dose, 1–5 mg/kg) also led to increased heart-to-body weight ratio and myocardial contractility changes. Acrolein induced similar hypotension in GSTP-null and WT mice. GSTP-null mice also were more susceptible than WT mice to mortality associated with high-dose acrolein (10–20 mg/kg). Collectively, these results suggest that CY cardiotoxicity is regulated, in part, by GSTP, which prevents CY toxicity by detoxifying acrolein. Thus, humans with low cardiac GSTP levels or polymorphic forms of GSTP with low acrolein-metabolizing capacity may be more sensitive to CY toxicity. - Graphical abstract: Cyclophosphamide (CY) treatment results in P450-mediated metabolic formation of phosphoramide mustard and acrolein (3-propenal). Acrolein is either metabolized and

  11. Glutathione S Transferases Polymorphisms Are Independent Prognostic Factors in Lupus Nephritis Treated with Cyclophosphamide.

    Directory of Open Access Journals (Sweden)

    Alexandra Audemard-Verger

    Full Text Available To investigate association between genetic polymorphisms of GST, CYP and renal outcome or occurrence of adverse drug reactions (ADRs in lupus nephritis (LN treated with cyclophosphamide (CYC. CYC, as a pro-drug, requires bioactivation through multiple hepatic cytochrome P450s and glutathione S transferases (GST.We carried out a multicentric retrospective study including 70 patients with proliferative LN treated with CYC. Patients were genotyped for polymorphisms of the CYP2B6, CYP2C19, GSTP1, GSTM1 and GSTT1 genes. Complete remission (CR was defined as proteinuria ≤0.33g/day and serum creatinine ≤124 µmol/l. Partial remission (PR was defined as proteinuria ≤1.5g/day with a 50% decrease of the baseline proteinuria value and serum creatinine no greater than 25% above baseline.Most patients were women (84% and 77% were Caucasian. The mean age at LN diagnosis was 41 ± 10 years. The frequency of patients carrying the GST null genotype GSTT1-, GSTM1-, and the Ile→105Val GSTP1 genotype were respectively 38%, 60% and 44%. In multivariate analysis, the Ile→105Val GSTP1 genotype was an independent factor of poor renal outcome (achievement of CR or PR (OR = 5.01 95% CI [1.02-24.51] and the sole factor that influenced occurrence of ADRs was the GSTM1 null genotype (OR = 3.34 95% CI [1.064-10.58]. No association between polymorphisms of cytochrome P450s gene and efficacy or ADRs was observed.This study suggests that GST polymorphisms highly impact renal outcome and occurrence of ADRs related to CYC in LN patients.

  12. Detection and adequacy evaluation of erythrocyte glutathione transferase on levels of circulating toxins in hemodialysis patients.

    Science.gov (United States)

    Yin, Rui; Qiu, Hui; Zuo, Huaiyun; Cui, Min; Zhai, Nailiang; Zheng, Hongguang; Zhang, Dewei; Huo, Ping; Hong, Min

    2016-08-01

    To explore detection and adequacy evaluation of erythrocyte glutathione S transferase (GST) on levels of circulating toxins in hemodialysis patients in Qinhuangdao region in China, this study divided 84 cases of long-term, end-stage hemodialysis patients into 2 groups: one group of 33 cases of adequate hemodialysis (spKt/V ≥ 1.3) and another group of 51 cases of inadequate hemodialysis (spKt/V GST, creatinine, high sensitivity C-reactive protein (hs-CRP), transferrin saturation (TSAT), parathyroid hormone (PTH), interleukin-2,6,8 (IL-2,6,8) and tumor necrosis factor-a (TNF-a) in the hemodialysis group were significantly higher than those in the control group (P GST, IL-2, 6, 8, and TNF-a levels in the inadequate hemodialysis group were significantly higher than in the adequate hemodialysis group (P GST and spKt/V, IL-2, IL-6, IL-8, and TNF-a have a positive correlation (P 0.05). There were 23 patients with levels of spKt/V ≥ 1.3 after adjusting the dialysis solution for 51 cases of inadequate hemodialysis patients, and the GST level after the adjustment was significantly lower than that before the adjustment, but still higher than that in the adequate dialysis group. This concludes that the maintenance of hemodialysis in patients has certain relevance on spKt/V and associated inflammatory factors. Through the study, it can be determined that GST can effectively respond to adequate hemodialysis, which has a guiding significance on adjusting the blood dialysis solution in clinical practice. PMID:27121915

  13. Glutathione S-Transferase Regulation in Calanus finmarchicus Feeding on the Toxic Dinoflagellate Alexandrium fundyense

    Science.gov (United States)

    Roncalli, Vittoria; Jungbluth, Michelle J.; Lenz, Petra H.

    2016-01-01

    The effect of the dinoflagellate, Alexandrium fundyense, on relative expression of glutathione S-transferase (GST) transcripts was examined in the copepod Calanus finmarchicus. Adult females were fed for 5-days on one of three experimental diets: control (100% Rhodomonas spp.), low dose of A. fundyense (25% by volume, 75% Rhodomonas spp.), and high dose (100% A. fundyense). Relative expression of three GST genes was measured using RT-qPCR on days 0.5, 1, 2 and 5 in two independent experiments. Differential regulation was found for the Delta and the Sigma GSTs between 0.5 to 2 days, but not on day 5 in both experiments. The third GST, a microsomal, was not differentially expressed in either treatment or day. RT-qPCR results from the two experiments were similar, even though experimental females were collected from the Gulf of Maine on different dates and their reproductive output differed. In the second experiment, expression of 39 GSTs was determined on days 2 and 5 using RNA-Seq. Global gene expression analyses agreed with the RT-qPCR results. Furthermore, the RNA-Seq measurements indicated that only four GSTs were differentially expressed under the experimental conditions, and the response was small in amplitude. In summary, the A. fundyense diet led to a rapid and transient response in C. finmarchicus in three cytosolic GSTs, while a fourth GST (Omega I) was significantly up-regulated on day 5. Although there was some regulation of GSTs in response the toxic dinoflagellate, the tolerance to A. fundyense by C. finmarchicus is not dependent on the long-term up-regulation of specific GSTs. PMID:27427938

  14. Ethnicity and glutathione S-transferase (GSTM1/GSTT1 polymorphisms in a Brazilian population

    Directory of Open Access Journals (Sweden)

    Gattás G.J.F.

    2004-01-01

    Full Text Available The distribution of polymorphisms related to glutathione S-transferases (GST has been described in different populations, mainly for white individuals. We evaluated the distribution of GST mu (GSTM1 and theta (GSTT1 genotypes in 594 individuals, by multiplex PCR-based methods, using amplification of the exon 7 of CYP1A1 gene as an internal control. In São Paulo, 233 whites, 87 mulattos, and 137 blacks, all healthy blood-donor volunteers, were tested. In Bahia, where black and mulatto populations are more numerous, 137 subjects were evaluated. The frequency of the GSTM1 null genotype was significantly higher among whites (55.4% than among mulattos (41.4%; P = 0.03 and blacks (32.8%; P < 0.0001 from São Paulo, or Bahian subjects in general (35.7%; P = 0.0003. There was no statistically different distribution among any non-white groups. The distribution of GSTT1 null genotype among groups did not differ significantly. The agreement between self-reported and interviewer classification of skin color in the Bahian group was low. The interviewer classification indicated a gradient of distribution of the GSTM1 null genotype from whites (55.6% to light mulattos (40.4%, dark mulattos (32.0% and blacks (28.6%. However, any information about race or ethnicity should be considered with caution regarding the bias introduced by different data collection techniques, specially in countries where racial admixture is intense, and ethnic definition boundaries are loose. Because homozygous deletions of GST gene might be associated with cancer risk, a better understanding of chemical metabolizing gene distribution can contribute to risk assessment of humans exposed to environmental carcinogens.

  15. Characterization of Ser73 in Arabidopsis thaliana Glutathione S-transferase zeta class

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Glutathione S-transferases (GSTs) are ubiquitous detoxifying superfamily enzymes. The zeta class GST from Arabidopsis thaliana (AtGSTZ) can efficiently degrade dichloroacetic acid (DCA), which is a common carcinogenic contaminant in drinking water. Ser73 in AtGSTZ is a conserved residue at Glutathione binding site (G-site). Compared with the equivalent residues in other GSTs, the catalytic and structural properties of Ser73 were poorly investigated. In this article, site-saturation mutagenesis was performed to characterize the detailed role of Ser73. The DCA de.chlorinating (DCA-DC) activity showed that most of the mutants had less than 3% of the wild-type activity, except S73T and $73A showing 43.48% and 21.62% of the wild-type activity, respectively, indicating that position 73 in AtGSTZ showed low mutational substitutability. Kinetic experiments revealed that mutants S73T, $73A, and S73G showed low binding affinity and catalytic efficiency toward DCA, 1.8-, 3.1-, and 10.7- fold increases in KmDcA values and 4.0-, 9.6-, and 34.1- fold decreases in KcatDCA/KmDCA values, respectively, compared to the wild type. Thermostability and refolding experiments showed that the wild type maintalned more thermostability and recovered activity. These results demonstrated the important role of Set73 in catalytic activity and structural stability of the enzyme. Such properties of Set73 could be particularly crucial to the molecular evolution of AtGSTZ and might,therefore, help explain why Ser73 is conserved in all GSTs. This conclusion might provide insights into the directed evolution of the DCA-DC activity of AtGSTZ.

  16. A role for glutathione transferase Omega 1 (GSTO1-1) in the glutathionylation cycle.

    Science.gov (United States)

    Menon, Deepthi; Board, Philip G

    2013-09-01

    The glutathionylation of intracellular protein thiols can protect against irreversible oxidation and can act as a redox switch regulating metabolic pathways. In this study we discovered that the Omega class glutathione transferase GSTO1-1 plays a significant role in the glutathionylation cycle. The catalytic activity of GSTO1-1 was determined in vitro by assaying the deglutathionylation of a synthetic peptide by tryptophan fluorescence quenching and in T47-D epithelial breast cancer cells by both immunoblotting and the direct determination of total glutathionylation. Mutating the active site cysteine residue (Cys-32) ablated the deglutathionylating activity of GSTO1-1. Furthermore, we demonstrate that the expression of GSTO1-1 in T47-D cells that are devoid of endogenous GSTO1-1 resulted in a 50% reduction in total glutathionylation levels. Mass spectrometry and immunoprecipitation identified β-actin as a protein that is specifically deglutathionylated by GSTO1-1 in T47-D cells. In contrast to the deglutathionylation activity, we also found that GSTO1-1 is associated with the rapid glutathionylation of cellular proteins when the cells are exposed to S-nitrosoglutathione. The common A140D genetic polymorphism in GSTO1 was found to have significant effects on the kinetics of both the deglutathionylation and glutathionylation reactions. Genetic variation in GSTO1-1 has been associated with a range of diseases, and the discovery that a frequent GSTO1-1 polymorphism affects glutathionylation cycle reactions reveals a common mechanism where it can act on multiple proteins and pathways.

  17. Trimeric microsomal glutathione transferase 2 displays one third of the sites reactivity.

    Science.gov (United States)

    Ahmad, Shabbir; Thulasingam, Madhuranayaki; Palombo, Isolde; Daley, Daniel O; Johnson, Kenneth A; Morgenstern, Ralf; Haeggström, Jesper Z; Rinaldo-Matthis, Agnes

    2015-10-01

    Human microsomal glutathione transferase 2 (MGST2) is a trimeric integral membrane protein that belongs to the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG) family. The mammalian MAPEG family consists of six members where four have been structurally determined. MGST2 activates glutathione to form a thiolate that is crucial for GSH peroxidase activity and GSH conjugation reactions with electrophilic substrates, such as 1-chloro-2,4-dinitrobenzene (CDNB). Several studies have shown that MGST2 is able to catalyze a GSH conjugation reaction with the epoxide LTA4 forming the pro-inflammatory LTC4. Unlike its closest homologue leukotriene C4 synthase (LTC4S), MGST2 appears to activate its substrate GSH using only one of the three potential active sites [Ahmad S, et al. (2013) Biochemistry. 52, 1755-1764]. In order to demonstrate and detail the mechanism of one-third of the sites reactivity of MGST2, we have determined the enzyme oligomeric state, by Blue native PAGE and Differential Scanning Calorimetry, as well as the stoichiometry of substrate and substrate analog inhibitor binding to MGST2, using equilibrium dialysis and Isothermal Titration Calorimetry, respectively. Global simulations were used to fit kinetic data to determine the catalytic mechanism of MGST2 with GSH and CDNB (1-chloro-2,4-dinitrobenzene) as substrates. The best fit was observed with 1/3 of the sites catalysis as compared with a simulation where all three sites were active. In contrast to LTC4S, MGST2 displays a 1/3 the sites reactivity, a mechanism shared with the more distant family member MGST1 and recently suggested also for microsomal prostaglandin E synthase-1.

  18. Resistance to acetaminophen-induced hepatotoxicity in glutathione S-transferase Mu 1-null mice.

    Science.gov (United States)

    Arakawa, Shingo; Maejima, Takanori; Fujimoto, Kazunori; Yamaguchi, Takashi; Yagi, Masae; Sugiura, Tomomi; Atsumi, Ryo; Yamazoe, Yasushi

    2012-01-01

    We investigated the role of glutathione S-transferases Mu 1 (GSTM1) in acetaminophen (APAP)-induced hepatotoxicity using Gstm1-null mice. A single oral administration of APAP resulted in a marked increase in plasma alanine aminotransferase accompanied by hepatocyte necrosis 24 hr after administration in wild-type mice, but its magnitude was unexpectedly attenuated in Gstm1-null mice. Therefore, it is suggested that Gstm1-null mice are resistant to APAP-induced hepatotoxicity. To examine the mechanism of this resistance in Gstm1-null mice, we measured phosphorylation of c-jun N-terminal kinase (JNK), which mediates the signal of APAP-induced hepatocyte necrosis, by Western blot analysis 2 and 6 hr after APAP administration. A marked increase in phosphorylated JNK was observed in wild-type mice, but the increase was markedly suppressed in Gstm1-null mice. Therefore, it is suggested that suppressed phosphorylation of JNK may be a main mechanism of the resistance to APAP-induced hepatotoxicity in Gstm1-null mice, although other possibilities of the mechanism cannot be eliminated. Additionally, phosphorylation of glycogen synthase kinase-3β and mitogen-activated protein kinase kinase 4, which are upstream kinases of JNK in APAP-induced hepatotoxicity, were also suppressed in Gstm1-null mice. A decrease in liver total glutathione 2 hr after APAP administration, which is an indicator for exposure to N-acetyl-p-benzoquinoneimine, the reactive metabolite of APAP, were similar in wild-type and Gstm1-null mice. In conclusion, Gstm1-null mice are considered to be resistant to APAP-induced hepatotoxicity perhaps by the suppression of JNK phosphorylation. This study indicates the novel role of GSTM1 as a factor mediating the cellular signal for APAP-induced hepatotoxicity.

  19. Characterization and functional analysis of four glutathione S-transferases from the migratory locust, Locusta migratoria.

    Science.gov (United States)

    Qin, Guohua; Jia, Miao; Liu, Ting; Zhang, Xueyao; Guo, Yaping; Zhu, Kun Yan; Ma, Enbo; Zhang, Jianzhen

    2013-01-01

    Glutathione S-transferases (GSTs) play an important role in detoxification of xenobiotics in both prokaryotic and eukaryotic cells. In this study, four GSTs (LmGSTd1, LmGSTs5, LmGSTt1, and LmGSTu1) representing different classes were identified from the migratory locust, Locusta migratoria. These four proteins were heterologously expressed in Escherichia coli as soluble fusion proteins, purified by Ni(2+)-nitrilotriacetic acid agarose column and biochemically characterized. LmGSTd1, LmGSTs5, and LmGSTu1 showed high activities with 1-chloro-2, 4-dinitrobenzene (CDNB), detectable activity with p-nitro-benzyl chloride (p-NBC) and 1, 2-dichloro-4-nitrobenzene (DCNB), whereas LmGSTt1 showed high activity with p-NBC and detectable activity with CDNB. The optimal pH of the locust GSTs ranged between 7.0 to 9.0. Ethacrynic acid and reactive blue effectively inhibited all four GSTs. LmGSTs5 was most sensitive to heavy metals (Cu(2+) and Cd(2+)). The maximum expression of the four GSTs was observed in Malpighian tubules and fat bodies as evaluated by western blot. The nymph mortalities after carbaryl treatment increased by 28 and 12% after LmGSTs5 and LmGSTu1 were silenced, respectively. The nymph mortalities after malathion and chlorpyrifos treatments increased by 26 and 18% after LmGSTs5 and LmGSTu1 were silenced, respectively. These results suggest that sigma GSTs in L. migratoria play a significant role in carbaryl detoxification, whereas some of other GSTs may also involve in the detoxification of carbaryl and chlorpyrifos.

  20. Functional characterization of glutathione S-transferases associated with insecticide resistance in Tetranychus urticae.

    Science.gov (United States)

    Pavlidi, Nena; Tseliou, Vasilis; Riga, Maria; Nauen, Ralf; Van Leeuwen, Thomas; Labrou, Nikolaos E; Vontas, John

    2015-06-01

    The two-spotted spider mite Tetranychus urticae is one of the most important agricultural pests world-wide. It is extremely polyphagous and develops resistance to acaricides. The overexpression of several glutathione S-transferases (GSTs) has been associated with insecticide resistance. Here, we functionally expressed and characterized three GSTs, two of the delta class (TuGSTd10, TuGSTd14) and one of the mu class (TuGSTm09), which had been previously associated with striking resistance phenotypes against abamectin and other acaricides/insecticides, by transcriptional studies. Functional analysis showed that all three GSTs were capable of catalyzing the conjugation of both 1-chloro-2,4 dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene(DCNB) to glutathione (GSH), as well as exhibiting GSH-dependent peroxidase activity toward Cumene hydroperoxide (CumOOH). The steady-state kinetics of the T. urticae GSTs for the GSH/CDNB conjugation reaction were determined and compared with other GSTs. The interaction of the three recombinant proteins with several acaricides and insecticides was also investigated. TuGSTd14 showed the highest affinity toward abamectin and a competitive type of inhibition, which suggests that the insecticide may bind to the H-site of the enzyme. The three-dimensional structure of the TuGSTd14 was predicted based on X-ray structures of delta class GSTs using molecular modeling. Structural analysis was used to identify key structural characteristics and to provide insights into the substrate specificity and the catalytic mechanism of TuGSTd14.

  1. Genetic polymorphism in three glutathione s-transferase genes and breast cancer risk; TOPICAL

    International Nuclear Information System (INIS)

    The role of the glutathione S-transferase (GST) enzyme family is to detoxify environmental toxins and carcinogens and to protect organisms from their adverse effects, including cancer. The genes GSTM1, GSTP1, and GSTT1 code for three GSTs involved in the detoxification of carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and benzene. In humans, GSTM1 is deleted in about 50% of the population, GSTT1 is absent in about 20%, whereas the GSTP1 gene has a single base polymorphism resulting in an enzyme with reduced activity. Epidemiological studies indicate that GST polymorphisms increase the level of carcinogen-induced DNA damage and several studies have found a correlation of polymorphisms in one of the GST genes and an increased risk for certain cancers. We examined the role of polymorphisms in genes coding for these three GST enzymes in breast cancer. A breast tissue collection consisting of specimens of breast cancer patients and non-cancer controls was analyzed by polymerase chain reaction (PCR) for the presence or absence of the GSTM1 and GSTT1 genes and for GSTP1 single base polymorphism by PCR/RFLP. We found that GSTM1 and GSTT1 deletions occurred more frequently in cases than in controls, and GSTP1 polymorphism was more frequent in controls. The effective detoxifier (putative low-risk) genotype (defined as presence of both GSTM1 and GSTT1 genes and GSTP1 wild type) was less frequent in cases than controls (16% vs. 23%, respectively). The poor detoxifier (putative high-risk) genotype was more frequent in cases than controls. However, the sample size of this study was too small to provide conclusive results

  2. Cloning of a glutathione S-transferase decreasing during differentiation of HL60 cell line

    International Nuclear Information System (INIS)

    By sequencing the Expressed Sequence Tags of human dermal papilla cDNA library, we identified a clone named K872 of which the expression decreased during differentiation of HL60 cell line. K872 plasmid DNA was isolated according to QIA plasmid extraction kit (Qiagen GmbH, Germany). The nucleotide sequencing was performed by Sanger's method with K872 plasmid DNA. The most updated GenBank EMBL necleic acid banks were searched through the internet by using BLAST (Basic Local Alignment Search Tools) program. Northern bots were performed using RNA isolated from various human tissues and cancer cell lines. The gene expression of the fusion protein was achieved by His-Patch Thiofusion expression system and the protein product was identified on SDS-PAGE. K872 clone is 1006 nucleotides long, and has a coding region of 675 nucleotides and a 3' non-coding region of 280 nucleotides. The presumed open reading frame starting at the 5' terminus of K872 encodes 226 amino acids, including the initiation methionine residue. The amino acid sequence deduced from the open reading frame of K872 shares 70% identity with that of rat glutathione S-transferase kappa 1 (rGSTK1). The transcripts were expressed inh a variety of human tissues and cancer cells. The levels of transcript were relatively high in those tissues such as heart, skeletal muscle, and peripheral blood leukocyte. It is noteworthy that K872 was found to be abundantly expressed in colorectal cancer and melanoma cell lines. Homology search result suggests that K872 clone is the human homolog of the rGSTK1 which is known to be involved in the resistance of cytotoxic therapy. We propose that meticulous functional analysis should be followed to confirm that

  3. Enhanced tolerance and remediation of anthracene by transgenic tobacco plants expressing a fungal glutathione transferase gene

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Prachy; Mukherjee, Prasun K.; Sherkhane, Pramod D.; Kale, Sharad P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Eapen, Susan, E-mail: eapenhome@yahoo.com [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2011-08-15

    Highlights: {yields} Transgenic plants expressing a TvGST gene were tested for tolerance, uptake and degradation of anthracene. {yields} Transgenic plants were more tolerant to anthracene and take up more anthracene from soil and solutions compared to control plants. {yields} Using in vitro T{sub 1} seedlings, we showed that anthracene-a three fused benzene ring compound was phytodegraded to naphthalene derivatives, having two benzene rings. {yields} This is the first time that a transgenic plant was shown to have the potential to phytodegrade anthracene. - Abstract: Plants can be used for remediation of polyaromatic hydrocarbons, which are known to be a major concern for human health. Metabolism of xenobiotic compounds in plants occurs in three phases and glutathione transferases (GST) mediate phase II of xenobiotic transformation. Plants, although have GSTs, they are not very efficient for degradation of exogenous recalcitrant xenobiotics including polyaromatic hydrocarbons. Hence, heterologous expression of efficient GSTs in plants may improve their remediation and degradation potential of xenobiotics. In the present study, we investigated the potential of transgenic tobacco plants expressing a Trichoderma virens GST for tolerance, remediation and degradation of anthracene-a recalcitrant polyaromatic hydrocarbon. Transgenic plants with fungal GST showed enhanced tolerance to anthracene compared to control plants. Remediation of {sup 14}C uniformly labeled anthracene from solutions and soil by transgenic tobacco plants was higher compared to wild-type plants. Transgenic plants (T{sub 0} and T{sub 1}) degraded anthracene to naphthalene derivatives, while no such degradation was observed in wild-type plants. The present work has shown that in planta expression of a fungal GST in tobacco imparted enhanced tolerance as well as higher remediation potential of anthracene compared to wild-type plants.

  4. Glutathione S-transferase genotypes modify lung function decline in the general population: SAPALDIA cohort study

    Directory of Open Access Journals (Sweden)

    Ackermann-Liebrich Ursula

    2007-01-01

    Full Text Available Abstract Background Understanding the environmental and genetic risk factors of accelerated lung function decline in the general population is a first step in a prevention strategy against the worldwide increasing respiratory pathology of chronic obstructive pulmonary disease (COPD. Deficiency in antioxidative and detoxifying Glutathione S-transferase (GST gene has been associated with poorer lung function in children, smokers and patients with respiratory diseases. In the present study, we assessed whether low activity variants in GST genes are also associated with accelerated lung function decline in the general adult population. Methods We examined with multiple regression analysis the association of polymorphisms in GSTM1, GSTT1 and GSTP1 genes with annual decline in FEV1, FVC, and FEF25–75 during 11 years of follow-up in 4686 subjects of the prospective SAPALDIA cohort representative of the Swiss general population. Effect modification by smoking, gender, bronchial hyperresponisveness and age was studied. Results The associations of GST genotypes with FEV1, FVC, and FEF25–75 were comparable in direction, but most consistent for FEV1. GSTT1 homozygous gene deletion alone or in combination with GSTM1 homozygous gene deletion was associated with excess decline in FEV1 in men, but not women, irrespective of smoking status. The additional mean annual decline in FEV1 in men with GSTT1 and concurrent GSTM1 gene deletion was -8.3 ml/yr (95% confidence interval: -12.6 to -3.9 relative to men without these gene deletions. The GSTT1 effect on the FEV1 decline comparable to the observed difference in FEV1 decline between never and persistent smoking men. Effect modification by gender was statistically significant. Conclusion Our results suggest that genetic GSTT1 deficiency is a prevalent and strong determinant of accelerated lung function decline in the male general population.

  5. Tunicamycin-induced inhibition of a glycolipid:GalNAc-transferase in guinea pig tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Das, K.K.; Basu, M.; Basu, S.

    1986-05-01

    It is not known how many glycosyltransferases are glycoprotein or phosphoprotein in nature. Post-translational modification of the glycosyltransferases and their regulation in normal and tumor cells are of the present interest. Recently, the authors established the biosynthesis in vitro of GbOse4Cer and GbOse5Cer from GbOse3Cer by two different GalNAc-transferases (GalNAcT-2 and GalNAcT-3) isolated from chemically transformed guinea pig tumor cells (104Cl and 106B). When these cells were incubated in the presence of tunicamycin (0.2-2 ..mu..g/ml), the activity of GalNAcT-2 (UDP-GalNAc:GbOse3Cer(..beta..1-3)GalNAcT) was inhibited (90%), whereas GalT-4 (UDP-Gal:LcOse3Cer(..beta..1-4)GalT) and GalT-5 (UDP-Gal:LcOse5Cer(..cap alpha..1-3)GalT) remained unchanged. The effect of tunicamycin was minimal within 6 hrs of treatment. However, 50% and 75% inhibition was observed after treatment of these cells for 12 and 24 hr, respectively. The inhibitory effect of tunicamycin on GalNAcT-2 can be reversed after 12-24 hr of its removal from the medium. The incorporation of (/sup 3/H)-leucine in total protein remained unchanged during tunicamycin treatment. The inhibition of glycoproteins was further confirmed by the inhibition (95%) of (2-/sup 3/H)Man incorporation in the acid precipitable material. When cells were grown in the presence of insulin, the GalNAcT-2 activity increased 2-fold. Involvement of a glycoprotein catalytic subunit or a modifier protein in the GalNAcT-2 catalyzed reaction is under investigation.

  6. Overexpression of GalNAc-transferase GalNAc-T3 promotes pancreatic cancer cell growth.

    Science.gov (United States)

    Taniuchi, K; Cerny, R L; Tanouchi, A; Kohno, K; Kotani, N; Honke, K; Saibara, T; Hollingsworth, M A

    2011-12-01

    O-linked glycans of secreted and membrane-bound proteins have an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc:polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in human pancreatic cancer tissues and suppression of GalNAc-T3 significantly attenuates the growth of pancreatic cancer cells in vitro and in vivo. In addition, suppression of GalNAc-T3 induces apoptosis of pancreatic cancer cells. Our results indicate that GalNAc-T3 is likely involved in pancreatic carcinogenesis. Modification of cellular glycosylation occurs in nearly all types of cancer as a result of alterations in the expression levels of glycosyltransferases. We report guanine the nucleotide-binding protein, α-transducing activity polypeptide-1 (GNAT1) as a possible substrate protein of GalNAc-T3. GalNAc-T3 is associated with O-glycosylation of GNAT1 and affects the subcellular distribution of GNAT1. Knocking down endogenous GNAT1 significantly suppresses the growth/survival of PDAC cells. Our results imply that GalNAc-T3 contributes to the function of O-glycosylated proteins and thereby affects the growth and survival of pancreatic cancer cells. Thus, substrate proteins of GalNAc-T3 should serve as important therapeutic targets for pancreatic cancers.

  7. Structural analysis of an epsilon-class glutathione transferase from housefly, Musca domestica.

    Science.gov (United States)

    Nakamura, Chihiro; Yajima, Shunsuke; Miyamoto, Toru; Sue, Masayuki

    2013-01-25

    Glutathione transferases (GSTs) play an important role in the detoxification of insecticides, and as such, they are a key contributor to enhanced resistance to insecticides. In the housefly (Musca domestica), two epsilon-class GSTs (MdGST6A and MdGST6B) that share high sequence homology have been identified, which are believed to be involved in resistance against insecticides. The structural determinants controlling the substrate specificity and enzyme activity of MdGST6s are unknown. The aim of this study was to crystallize and perform structural analysis of the GST isozyme, MdGST6B. The crystal structure of MdGST6B complexed with reduced glutathione (GSH) was determined at a resolution of 1.8 Å. MdGST6B was found to have a typical GST folding comprised of N-terminal and C-terminal domains. Arg113 and Phe121 on helix 4 were shown to protrude into the substrate binding pocket, and as a result, the entrance of the substrate binding pocket was narrower compared to delta- and epsilon-class GSTs from Africa malaria vector Anopheles gambiae, agGSTd1-6 and agGSTe2, respectively. This substrate pocket narrowing is partly due to the presence of a π-helix in the middle of helix 4. Among the six residues that donate hydrogen bonds to GSH, only Arg113 was located in the C-terminal domain. Ala substitution of Arg113 did not have a significant effect on enzyme activity, suggesting that the Arg113 hydrogen bond does not play a crucial role in catalysis. On the other hand, mutation at Phe108, located just below Arg113 in the binding pocket, reduced the affinity and catalytic activity to both GSH and the electrophilic co-substrate, 1-chloro-2,4-dinitrobenzene.

  8. Functional characterization of alpha-class glutathione s-transferases from the Turkey (meleagris gallopavo).

    Science.gov (United States)

    Kim, Ji Eun; Bunderson, Brett R; Croasdell, Amanda; Coulombe, Roger A

    2011-11-01

    Six Alpha-class glutathione S-transferase (GST) subunits were cloned from domestic turkey livers, which are one of the most susceptible animals known to the carcinogenic mycotoxin aflatoxin B₁. In most animals, GST dysfunction is a risk factor for susceptibility toward AFB₁, and we have shown that turkeys lack GSTs with affinity toward the carcinogenic intermediate exo-aflatoxin B(1)-8-9-epoxide (AFBO). Conversely, mice are resistant to AFB₁ carcinogenesis, due to high constitutive expression of mGSTA3 that has high affinity toward AFBO. When expressed in Escherichia coli, all six tGSTA subunits possessed conjugating activities toward substrates 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene (DCNB), ethacrynic acid (ECA), and cumene hydroperoxide (CHP) with tGSTA1.2 appearing most active. Interestingly, tGSTA1.1, which lacks one of the four Alpha-class signature motifs, possessed enzymatic activities toward all substrates. All had comparable activities toward AFBO conjugation, an activity absent in turkey liver cytosols. E. coli-expressed mGSTA3 conjugated AFBO with more than 3-fold greater activity than that of tGSTAs and had higher activity toward GST prototype substrates. Mouse hepatic cytosols had approximately 900-fold higher catalytic activity toward AFBO compared with those from turkey. There was no apparent amino acid profile in tGSTAs that might correspond to specificity toward AFBO, although tGSTA1.2, which had slightly higher AFBO-trapping ability, shared Tyr¹⁰⁸ with mGSTA3, a residue postulated to be critical for AFBO trapping activity in mammalian systems. The observation that recombinant tGSTAs detoxify AFBO, whereas their hepatic forms do not, implies that the hepatic forms of these enzymes are silenced by one or more regulatory mechanisms.

  9. Glutathione-S-transferases in lung and sputum specimens, effects of smoking and COPD severity

    Science.gov (United States)

    Harju, Terttu; Mazur, Witold; Merikallio, Heta; Soini, Ylermi; Kinnula, Vuokko L

    2008-01-01

    Background Oxidative stress plays a potential role in the pathogenesis and progression of chronic obstructive pulmonary disease (COPD). Glutathione S-transferases (GSTs) detoxify toxic compounds in tobacco smoke via glutathione-dependent mechanisms. Little is known about the regulation and expression of GSTs in COPD lung and their presence in airway secretions. Methods GST alpha, pi and mu were investigated by immunohistochemistry in 72 lung tissue specimens and by Western analysis in total lung homogenates and induced sputum supernatants from non-smokers, smokers and patients with variable stages of COPD severity. Results GST alpha was expressed mainly in the airway epithelium. The percentage of GST alpha positive epithelial cells was lower in the central airways of patients with very severe (Stage IV) COPD compared to mild/moderate COPD (p = 0.02). GST alpha by Western analysis was higher in the total lung homogenates in mild/moderate COPD compared to cases of very severe disease (p < 0.001). GST pi was present in airway and alveolar epithelium as well as in alveolar macrophages. GST mu was expressed mainly in the epithelium. Both GST alpha and pi were detectable in sputum supernatants especially in patients with COPD. Conclusion This study indicates the presence of GST alpha and pi especially in the epithelium and sputum supernatants in mild/moderate COPD and low expression of GST alpha in the epithelium in cases of very severe COPD. The presence of GSTs in the airway secretions points to their potential protective role both as intracellular and extracellular mediators in human lung. PMID:19077292

  10. Glutathione S-Transferase Polymorphisms, Passive Smoking, Obesity, and Heart Rate Variability in Nonsmokers

    Science.gov (United States)

    Probst-Hensch, Nicole M.; Imboden, Medea; Dietrich, Denise Felber; Barthélemy, Jean-Claude; Ackermann-Liebrich, Ursula; Berger, Wolfgang; Gaspoz, Jean-Michel; Schwartz, Joel

    2008-01-01

    Background Disturbances of heart rate variability (HRV) may represent one pathway by which second-hand smoke (SHS) and air pollutants affect cardiovascular morbidity and mortality. The mechanisms are poorly understood. Objectives We investigated the hypothesis that oxidative stress alters cardiac autonomic control. We studied the association of polymorphisms in oxidant-scavenging glutathione S-transferase (GST) genes and their interactions with SHS and obesity with HRV. Methods A total of 1,133 nonsmokers > 50 years of age from a population-based Swiss cohort underwent ambulatory 24-hr electrocardiogram monitoring and reported on lifestyle and medical history. We genotyped GSTM1 and GSTT1 gene deletions and a GSTP1 (Ile105Val) single nucleotide polymorphism and analyzed genotype–HRV associations by multiple linear regressions. Results Homozygous GSTT1 null genotypes exhibited an average 10% decrease in total power (TP) and low-frequency-domain HRV parameters. All three polymorphisms modified the cross-sectional associations of HRV with SHS and obesity. Homozygous GSTM1 null genotypes with > 2 hr/day of SHS exposure exhibited a 26% lower TP [95% confidence interval (CI), 11 to 39%], versus a reduction of −5% (95% CI, −22 to 17%) in subjects with the gene and the same SHS exposure compared with GSTM1 carriers without SHS exposure. Similarly, obese GSTM1 null genotypes had, on average, a 22% (95% CI, 12 to 31%) lower TP, whereas with the gene present obesity was associated with only a 3% decline (95% CI, −15% to 10%) compared with nonobese GSTM1 carriers. Conclusions GST deficiency is associated with significant HRV alterations in the general population. Its interaction with SHS and obesity in reducing HRV is consistent with an impact of oxidative stress on the autonomous nervous system. PMID:19057702

  11. Labeling embryonic stem cells with enhanced green fluorescent protein on the hypoxanthineguanine phosphoribosyl transferase locus

    Institute of Scientific and Technical Information of China (English)

    滕路; 孟国良; 刑阳; 尚克刚; 王小珂; 顾军

    2003-01-01

    Objective To label embryonic stem (ES) cells with enhanced green fluorescent protein (EGF P) on the hypoxanthineguanine phosphoribosyl transferase (HPRT) gene locus for t he first time to provide a convenient and efficient way for cell tracking and ma nipulation in the studies of transplantation and stem cell therapy.Methods Homologous fragments were obtained by polymerase chain reaction (PCR), from whic h the gene targeting vector pHPRT-EGFP was constructed. The linearized vector was introduced into ES cells by electroporation. The G418r6TGr cell clones were obtained after selection with G418 and 6TG media. The integration patterns of these resistant cell clones were identified with Southern blotting.Results EGFP expressing ES cells on the locus of HPRT were successfu lly generated. They have normal properties, such as karyotype, viability and di fferentiation ability. The green fluorescence of EGFP expressing cells was main tained in propagation of the ES cells for more than 30 passages and in different iated cells. Cultured in suspension, the "green" ES cells aggregated and forme d embryoid bodies, retaining the green fluorescence at varying developmental sta ges. The "green" embryoid bodies could expand and differentiate into various t ypes of cells, exhibiting ubiquitous green fluorescence. Conclusions This generation of "green" targeted ES cells is described in an efficient proto col for obtaining the homologous fragments by PCR. Introducing the marker gene in the genome of ES cells, we should be able to manipulate them in vitro and use them as vehicles in cell-replacement therapy as well as for other biomedical a nd research purposes.

  12. Glutathione transferase mu 2 protects glioblastoma cells against aminochrome toxicity by preventing autophagy and lysosome dysfunction

    Science.gov (United States)

    Huenchuguala, Sandro; Muñoz, Patricia; Zavala, Patricio; Villa, Mónica; Cuevas, Carlos; Ahumada, Ulises; Graumann, Rebecca; Nore, Beston F; Couve, Eduardo; Mannervik, Bengt; Paris, Irmgard; Segura-Aguilar, Juan

    2014-01-01

    U373MG cells constitutively express glutathione S-transferase mu 2 (GSTM2) and exhibit 3H-dopamine uptake, which is inhibited by 2 µM of nomifensine and 15 µM of estradiol. We generated a stable cell line (U373MGsiGST6) expressing an siRNA against GSTM2 that resulted in low GSTM2 expression (26% of wild-type U373MG cells). A significant increase in cell death was observed when U373MGsiGST6 cells were incubated with 50 µM purified aminochrome (18-fold increase) compared with wild-type cells. The incubation of U373MGsiGST6 cells with 75 µM aminochrome resulted in the formation of autophagic vacuoles containing undigested cellular components, as determined using transmission electron microscopy. A significant increase in autophagosomes was determined by measuring endogenous LC3-II, a significant decrease in cell death was observed in the presence of bafilomycin A1, and a significant increase in cell death was observed in the presence of trehalose. A significant increase in LAMP2 immunostaining was observed, a significant decrease in bright red fluorescence of lysosomes with acridine orange was observed, and bafilomycin A1 pretreatment reduced the loss of lysosome acidity. A significant increase in cell death was observed in the presence of lysosomal protease inhibitors. Aggregation of TUBA/α-tubulin (tubulin, α) and SQSTM1 protein accumulation were also observed. Moreover, a significant increase in the number of lipids droplets was observed compared with U373MG cells with normal expression of GSTM2. These results support the notion that GSTM2 is a protective enzyme against aminochrome toxicity in astrocytes and that aminochrome cell death in U373MGsiGST6 cells involves autophagic-lysosomal dysfunction. PMID:24434817

  13. Exploiting the Substrate Promiscuity of Hydroxycinnamoyl-CoA:Shikimate Hydroxycinnamoyl Transferase to Reduce Lignin.

    Science.gov (United States)

    Eudes, Aymerick; Pereira, Jose H; Yogiswara, Sasha; Wang, George; Teixeira Benites, Veronica; Baidoo, Edward E K; Lee, Taek Soon; Adams, Paul D; Keasling, Jay D; Loqué, Dominique

    2016-03-01

    Lignin poses a major challenge in the processing of plant biomass for agro-industrial applications. For bioengineering purposes, there is a pressing interest in identifying and characterizing the enzymes responsible for the biosynthesis of lignin. Hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyl transferase (HCT; EC 2.3.1.133) is a key metabolic entry point for the synthesis of the most important lignin monomers: coniferyl and sinapyl alcohols. In this study, we investigated the substrate promiscuity of HCT from a bryophyte (Physcomitrella) and from five representatives of vascular plants (Arabidopsis, poplar, switchgrass, pine and Selaginella) using a yeast expression system. We demonstrate for these HCTs a conserved capacity to acylate with p-coumaroyl-CoA several phenolic compounds in addition to the canonical acceptor shikimate normally used during lignin biosynthesis. Using either recombinant HCT from switchgrass (PvHCT2a) or an Arabidopsis stem protein extract, we show evidence of the inhibitory effect of these phenolics on the synthesis of p-coumaroyl shikimate in vitro, which presumably occurs via a mechanism of competitive inhibition. A structural study of PvHCT2a confirmed the binding of a non-canonical acceptor in a similar manner to shikimate in the active site of the enzyme. Finally, we exploited in Arabidopsis the substrate flexibility of HCT to reduce lignin content and improve biomass saccharification by engineering transgenic lines that overproduce one of the HCT non-canonical acceptors. Our results demonstrate conservation of HCT substrate promiscuity and provide support for a new strategy for lignin reduction in the effort to improve the quality of plant biomass for forage and cellulosic biofuels. PMID:26858288

  14. Genetic polymorphism in three glutathione s-transferase genes and breast cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Woldegiorgis, S.; Ahmed, R.C.; Zhen, Y.; Erdmann, C.A.; Russell, M.L.; Goth-Goldstein, R.

    2002-04-01

    The role of the glutathione S-transferase (GST) enzyme family is to detoxify environmental toxins and carcinogens and to protect organisms from their adverse effects, including cancer. The genes GSTM1, GSTP1, and GSTT1 code for three GSTs involved in the detoxification of carcinogens, such as polycyclic aromatic hydrocarbons (PAHs) and benzene. In humans, GSTM1 is deleted in about 50% of the population, GSTT1 is absent in about 20%, whereas the GSTP1 gene has a single base polymorphism resulting in an enzyme with reduced activity. Epidemiological studies indicate that GST polymorphisms increase the level of carcinogen-induced DNA damage and several studies have found a correlation of polymorphisms in one of the GST genes and an increased risk for certain cancers. We examined the role of polymorphisms in genes coding for these three GST enzymes in breast cancer. A breast tissue collection consisting of specimens of breast cancer patients and non-cancer controls was analyzed by polymerase chain reaction (PCR) for the presence or absence of the GSTM1 and GSTT1 genes and for GSTP1 single base polymorphism by PCR/RFLP. We found that GSTM1 and GSTT1 deletions occurred more frequently in cases than in controls, and GSTP1 polymorphism was more frequent in controls. The effective detoxifier (putative low-risk) genotype (defined as presence of both GSTM1 and GSTT1 genes and GSTP1 wild type) was less frequent in cases than controls (16% vs. 23%, respectively). The poor detoxifier (putative high-risk) genotype was more frequent in cases than controls. However, the sample size of this study was too small to provide conclusive results.

  15. Glutathione S-transferase activity in follicular fluid from women undergoing ovarian stimulation: role in maturation.

    Science.gov (United States)

    Meijide, Susana; Hernández, M Luisa; Navarro, Rosaura; Larreategui, Zaloa; Ferrando, Marcos; Ruiz-Sanz, José Ignacio; Ruiz-Larrea, M Begoña

    2014-10-01

    Female infertility involves an emotional impact for the woman, often leading to a state of anxiety and low self-esteem. The assisted reproduction techniques (ART) are used to overcome the problem of infertility. In a first step of the in vitro fertilization therapy women are subjected to an ovarian stimulation protocol to obtain mature oocytes, which will result in competent oocytes necessary for fertilization to occur. Ovarian stimulation, however, subjects the women to a high physical and psychological stress, thus being essential to improve ART and to find biomarkers of dysfunction and fertility. GSH is an important antioxidant, and is also used in detoxification reactions, catalysed by glutathione S-transferases (GST). In the present work, we have investigated the involvement of GST in follicular maturation. Patients with fertility problems and oocyte donors were recruited for the study. From each woman follicles at two stages of maturation were extracted at the preovulatory stage. Follicular fluid was separated from the oocyte by centrifugation and used as the enzyme source. GST activity was determined based on its conjugation with 3,4-dichloronitrobenzene and the assay was adapted to a 96-well microplate reader. The absorbance was represented against the incubation time and the curves were adjusted to linearity (R(2)>0.990). Results showed that in both donors and patients GST activity was significantly lower in mature oocytes compared to small ones. These results suggest that GST may play a role in the follicle maturation by detoxifying xenobiotics, thus contributing to the normal development of the oocyte. Supported by FIS/FEDER (PI11/02559), Gobierno Vasco (Dep. Educación, Universiades e Investigación, IT687-13), and UPV/EHU (CLUMBER UFI11/20 and PES13/58). The work was approved by the Ethics Committee of the UPV/EHU (CEISH/96/2011/RUIZLARREA), and performed according to the UPV/EHU and IVI-Bilbao agreement (Ref. 2012/01).

  16. Farnesyl transferase inhibitors induce extended remissions in transgenic mice with mature B cell lymphomas

    Directory of Open Access Journals (Sweden)

    Refaeli Yosef

    2008-05-01

    Full Text Available Abstract Background We have used a mouse model based on overexpression of c-Myc in B cells genetically engineered to be self-reactive to test the hypothesis that farnesyl transferase inhibitors (FTIs can effectively treat mature B cell lymphomas. FTIs are undergoing clinical trials to treat both lymphoid and non-lymphoid malignancies and we wished to obtain evidence to support the inclusion of B cell lymphomas in future trials. Results We report that two FTIs, L-744,832 and SCH66336, blocked the growth of mature B cell lymphoma cells in vitro and in vivo. The FTI treatment affected the proliferation and survival of the transformed B cells to a greater extent than naïve B cells stimulated with antigen. In syngeneic mice transplanted with the transgenic lymphoma cells, L-744,832 treatment prevented the growth of the tumor cells and the morbidity associated with the resulting lymphoma progression. Tumors that arose from transplantation of the lymphoma cells regressed with as little as three days of treatment with L-744,832 or SCH66336. Treatment of these established lymphomas with L-744,832 for seven days led to long-term remission of the disease in approximately 25% of animals. Conclusion FTI treatment can block the proliferation and survival of self-reactive transformed B cells that overexpress Myc. In mice transplanted with mature B cell lymphomas, we found that FTI treatment led to regression of disease. FTIs warrant further consideration as therapeutic agents for mature B cell lymphomas and other lymphoid tumors.

  17. Interaction of glutathione transferase P1-1 with captan and captafol.

    Science.gov (United States)

    di Ilio, C; Sacchetta, P; Angelucci, S; Bucciarelli, T; Pennelli, A; Mazzetti, A P; Lo Bello, M; Aceto, A

    1996-07-12

    Glutathione transferase (GST, EC 2.5.1.18) P1-1 was strongly inhibited by captan and captafol in a time- and concentration-dependent manner. The IC50 values for captan and captafol were 5.8 microM and 1.5 microM, respectively. Time-course inactivation of GSTP1-1 by two pesticides was prevented by 3 microM of hexyl-glutathione, but not by methylglutathione. The fact that the inactivated enzyme recovered all the 5,5'-dithiobis(2-nitrobenzoic acid) titrable thiol groups, with concomitant recovery of all its original activity after treatment with 100 microM dithiothreitol, suggested that captan and captafol were able to induce the formation of disulfide bonds. That the inactivation of GSTP1-1 by captan and captafol involves the formation of disulfide bonds between the four cysteinil groups of the enzymes was confirmed by the SDS-PAGE experiments on nondenaturant conditions. In fact, on SDS-PAGE, GSTP1-1 as well as the cys47ala, cys101ala, and cys47ala/cys101ala GSTP1-1 mutants treated with captan and captafol showed several extra bands, with apparent molecular masses higher and lower than the molecular mass of native GSTP1-1 (23.5 kDa), indicating that both intra- and inter-subunit disulfide bonds were formed. These extra bands returned to the native 23.5 kDa band with concomitant restoration of activity when treated with dithiothreitol.

  18. Deficiency of glutathione transferase zeta causes oxidative stress and activation of antioxidant response pathways.

    Science.gov (United States)

    Blackburn, Anneke C; Matthaei, Klaus I; Lim, Cindy; Taylor, Matthew C; Cappello, Jean Y; Hayes, John D; Anders, M W; Board, Philip G

    2006-02-01

    Glutathione S-transferase (GST) zeta (GSTZ1-1) plays a significant role in the catabolism of phenylalanine and tyrosine, and a deficiency of GSTZ1-1 results in the accumulation of maleylacetoacetate and its derivatives maleylacetone (MA) and succinylacetone. Induction of GST subunits was detected in the liver of Gstz1(-/-) mice by Western blotting with specific antisera and high-performance liquid chromatography analysis of glutathione affinity column-purified proteins. The greatest induction was observed in members of the mu class. Induction of NAD(P)H:quinone oxidoreductase 1 and the catalytic and modifier subunits of glutamate-cysteine ligase was also observed. Many of the enzymes that are induced in Gstz1(-/-) mice are regulated by antioxidant response elements that respond to oxidative stress via the Keap1/Nrf2 pathway. It is significant that diminished glutathione concentrations were also observed in the liver of Gstz1(-/-) mice, which supports the conclusion that under normal dietary conditions, the accumulation of electrophilic intermediates such as maleylacetoacetate and MA results in a high level of oxidative stress. Elevated GST activities in the livers of Gstz1(-/-) mice suggest that GSTZ1-1 deficiency may alter the metabolism of some drugs and xenobiotics. Gstz1(-/-) mice given acetaminophen demonstrated increased hepatotoxicity compared with wild-type mice. This toxicity may be attributed to the increased GST activity or the decreased hepatic concentrations of glutathione, or both. Patients with acquired deficiency of GSTZ1-1 caused by therapeutic exposure to dichloroacetic acid for the clinical treatment of lactic acidosis may be at increased risk of drug- and chemical-induced toxicity. PMID:16278372

  19. Rescue of Drosophila Melanogaster l(2)35Aa lethality is only mediated by polypeptide GalNAc-transferase pgant35A, but not by the evolutionary conserved human ortholog GalNAc-transferase-T11.

    Science.gov (United States)

    Bennett, Eric P; Chen, Ya-Wen; Schwientek, Tilo; Mandel, Ulla; Schjoldager, Katrine ter-Borch Gram; Cohen, Stephen M; Clausen, Henrik

    2010-05-01

    The Drosophila l(2)35Aa gene encodes a UDP-N-acetylgalactosamine: Polypeptide N-acetylgalactosaminyltransferase, essential for embryogenesis and development (J. Biol. Chem. 277, 22623-22638; J. Biol. Chem. 277, 22616-22). l(2)35Aa, also known as pgant35A, is a member of a large evolutionarily conserved family of genes encoding polypeptide GalNAc-transferases. Phylogenetic and functional analyses have proposed that subfamilies of orthologous GalNAc-transferase genes are conserved in species, suggesting that they serve distinct functions in vivo. Based on sequence alignments, pgant35A and human GALNT11 are thought to belong to a distinct subfamily. Recent in vitro studies have shown that pgant35A and pgant7, encoding enzymes from different subfamilies, prefer different acceptor substrates, whereas the orthologous pgant35A and human GALNT11 gene products possess, 1) conserved substrate preferences and 2) similar acceptor site preferences in vitro. In line with the in vitro pgant7 studies, we show that l(2)35Aa lethality is not rescued by ectopic pgant7 expression. Remarkably and in contrast to this observation, the human pgant35A ortholog, GALNT11, was shown not to support rescue of the l(2)35Aa lethality. By use of genetic "domain swapping" experiments we demonstrate, that lack of rescue was not caused by inappropriate sub-cellular targeting of functionally active GalNAc-T11. Collectively our results show, that fly embryogenesis specifically requires functional pgant35A, and that the presence of this gene product during fly embryogenesis is functionally distinct from other Drosophila GalNAc-transferase isoforms and from the proposed human ortholog GALNT11.

  20. Proteomic and immunochemical characterization of glutathione transferase as a new allergen of the nematode Ascaris lumbricoides.

    Directory of Open Access Journals (Sweden)

    Nathalie Acevedo

    Full Text Available Helminth infections and allergy have evolutionary and clinical links. Infection with the nematode Ascaris lumbricoides induces IgE against several molecules including invertebrate pan-allergens. These antibodies influence the pathogenesis and diagnosis of allergy; therefore, studying parasitic and non-parasitic allergens is essential to understand both helminth immunity and allergy. Glutathione transferases (GSTs from cockroach and house dust mites are clinically relevant allergens and comparative studies between them and the GST from A. lumbricoides (GSTA are necessary to evaluate their allergenicity. We sought to analyze the allergenic potential of GSTA in connection with the IgE response to non-parasitic GSTs. IgE to purified GSTs from Ascaris (nGSTA and rGSTA, house dust mites (rDer p 8, nBlo t 8 and rBlo t 8, and cockroach (rBla g 5 was measured by ELISA in subjects from Cartagena, Colombia. Also, multidimensional proteomic approaches were used to study the extract of A. lumbricoides and investigate the existence of GST isoforms. We found that among asthmatics, the strength of IgE levels to GSTA was significantly higher than to mite and cockroach GSTs, and there was a strong positive correlation between IgE levels to these molecules. Specific IgE to GSTA was found in 13.2% of controls and 19.5% of asthmatics. In addition nGSTA induced wheal and flare in skin of sensitized asthmatics indicating that it might be of clinical relevance for some patients. Frequency and IgE levels to GSTA were higher in childhood and declined with age. At least six GST isoforms in A. lumbricoides bind human IgE. Four isoforms were the most abundant and several amino acid substitutions were found, mainly on the N-terminal domain. In conclusion, a new allergenic component of Ascaris has been discovered; it could have clinical impact in allergic patients and influence the diagnosis of mite and cockroach allergy in tropical environments.

  1. Cloning and characterization of a biotic-stress-inducible glutathione transferase from Phaseolus vulgaris.

    Science.gov (United States)

    Chronopoulou, Evangelia; Madesis, Panagiotis; Tsaftaris, Athanasios; Labrou, Nikolaos E

    2014-01-01

    Glutathione transferases (GSTs, EC 2.5.1.18) are ubiquitous proteins in plants that play important roles in stress tolerance and in the detoxification of toxic chemicals and metabolites. In this study, we systematically examined the catalytic diversification of a GST isoenzyme from Phaseolus vulgaris (PvGST) which is induced under biotic stress treatment (Uromyces appendiculatus infection). The full-length cDNA of this GST isoenzyme (termed PvGSTU3-3) with complete open reading frame, was isolated using RACE-RT and showed that the deduced amino acid sequence shares high homology with the tau class plant GSTs. PvGSTU3-3 catalyzes several different reactions and exhibits wide substrate specificity. Of particular importance is the finding that the enzyme shows high antioxidant catalytic function and acts as hydroperoxidase, thioltransferase, and dehydroascorbate reductase. In addition, its K m for GSH is about five to ten times lower compared to other plant GSTs, suggesting that PvGSTU3-3 is able to perform efficient catalysis under conditions where the concentration of reduced glutathione is low (e.g., oxidative stress). Its ability to conjugate GSH with isothiocyanates may provide an additional role for this enzyme to act as a regulator of the released isothiocyanates from glucosinolates as a response of biotic stress. Molecular modeling showed that PvGSTU3-3 shares the same overall fold and structural organization with other plant cytosolic GSTs, with major differences at their hydrophobic binding sites (H-sites) and some differences at the level of C-terminal domain and the linker between the C- and N-terminal domains. PvGSTU3-3, in general, exhibits restricted ability to bind xenobiotics in a nonsubstrate manner, suggesting that the biological role of PvGSTU3-3, is restricted mainly to the catalytic function. Our findings highlight the functional and catalytic diversity of plant GSTs and demonstrate their pivotal role for addressing biotic stresses in Phaseolus

  2. Regulatory and functional interactions of plant growth regulators and plant glutathione S-transferases (GSTs).

    Science.gov (United States)

    Moons, Ann

    2005-01-01

    Plant glutathioneS-transferases (GSTs) are a heterogeneous superfamily of multifunctional proteins, grouped into six classes. The tau (GSTU) and phi (GSTF) class GSTs are the most represented ones and are plant-specific, whereas the smaller theta (GSTT) and zeta (GSTZ) classes are also found in animals. The lambda GSTs (GSTL) and the dehydroascorbate reductases (DHARs) are more distantly related. Plant GSTs perform a variety of pivotal catalytic and non-enzymatic functions in normal plant development and plant stress responses, roles that are only emerging. Catalytic functions include glutathione (GSH)-conjugation in the metabolic detoxification of herbicides and natural products. GSTs can also catalyze GSH-dependent peroxidase reactions that scavenge toxic organic hydroperoxides and protect from oxidative damage. GSTs can furthermore catalyze GSH-dependent isomerizations in endogenous metabolism, exhibit GSH-dependent thioltransferase safeguarding protein function from oxidative damage and DHAR activity functioning in redox homeostasis. Plant GSTs can also function as ligandins or binding proteins for phytohormones (i.e., auxins and cytokinins) or anthocyanins, thereby facilitating their distribution and transport. Finally, GSTs are also indirectly involved in the regulation of apoptosis and possibly also in stress signaling. Plant GST genes exhibit a diversity of expression patterns during biotic and abiotic stresses. Stress-induced plant growth regulators (i.e., jasmonic acid [JA], salicylic acid [SA], ethylene [ETH], and nitric oxide [NO] differentially activate GST gene expression. It is becoming increasingly evident that unique combinations of multiple, often interactive signaling pathways from various phytohormones and reactive oxygen species or antioxidants render the distinct transcriptional activation patterns of individual GSTs during stress. Underestimated post-transcriptional regulations of individual GSTs are becoming increasingly evident and roles

  3. In vivo induction of phase II detoxifying enzymes, glutathione transferase and quinone reductase by citrus triterpenoids

    Directory of Open Access Journals (Sweden)

    Ahmad Hassan

    2010-09-01

    Full Text Available Abstract Background Several cell culture and animal studies demonstrated that citrus bioactive compounds have protective effects against certain types of cancer. Among several classes of citrus bioactive compounds, limonoids were reported to prevent different types of cancer. Furthermore, the structures of citrus limonoids were reported to influence the activity of phase II detoxifying enzymes. The purpose of the study was to evaluate how variations in the structures of citrus limonoids (namely nomilin, deacetyl nomilin, and isoobacunoic acid and a mixture of limonoids would influence phase II enzyme activity in excised tissues from a mouse model. Methods In the current study, defatted sour orange seed powder was extracted with ethyl acetate and subjected to silica gel chromatography. The HPLC, NMR and mass spectra were used to elucidate the purity and structure of compounds. Female A/J mice were treated with three limonoids and a mixture in order to evaluate their effect on phase II enzymes in four different tissues. Assays for glutathione S-transferase and NAD(PH: quinone reductase (QR were used to evaluate induction of phase II enzymatic activity. Results The highest induction of GST against 1-chloro-2,4-dinitrobenzene (CDNB was observed in stomach (whole, 58% by nomilin, followed by 25% isoobacunoic acid and 19% deacetyl nomilin. Deacetyl nomilin in intestine (small as well as liver significantly reduced GST activity against CDNB. Additionally isoobacunoic acid and the limonoid mixture in liver demonstrated a significant reduction of GST activity against CDNB. Nomilin significantly induced GST activity against 4-nitroquinoline 1-oxide (4NQO, intestine (280% and stomach (75% while deacetyl nomilin showed significant induction only in intestine (73%. Induction of GST activity was also observed in intestine (93% and stomach (45% treated with the limonoid mixture. Finally, a significant induction of NAD(PH: quinone reductase (QR activity was

  4. Proteomic analysis of glutathione S-transferase isoforms in mouse liver mitochondria

    Institute of Scientific and Technical Information of China (English)

    Hai-Dan Sun; Ya-Wei Ru; Dong-Juan Zhang; Song-Yue Yin; Liang Yin; Ying-Ying Xie; You-Fei Guan; Si-Qi Liu

    2012-01-01

    AIM:To survey glutathione (GSH) S-transferase (GST)isoforms in mitochondria and to reveal the isoforms' biological significance in diabetic mice.METHODS:The presence of GSTs in mouse liver mitochondria was systematically screened by two proteomic approaches,namely,GSH affinity chromatography/two dimensional electrophoresis (2DE/MALDI TOF/TOFMS) and SDS-PAGE/LC ESI MS/MS.The proteomic results were further confirmed by Western blotting using monoclonal antibodies against GSTs.To evaluate the liver mitochondrial GSTs quantitatively,calibration curves were generated by the loading amounts of individual recombinant GST protein vs the relative intensities elicited from the Western blotting.An extensive comparison of the liver mitochondrial GSTs was conducted between normal and db/db diabetic mice.Student's t test was adopted for the estimation of regression and significant difference.RESULTS:Using GSH affinity/2DF/MALDI TOF/TOF MS,three GSTs,namely,alpha3,mu1 and pi1,were identified; whereas five GSTs,alpha3,mu1,pi1,kappa1 and zeta1,were detected in mouse liver mitochondria using SDS-PAGE/LC ESI MS/MS,of these GSTs,GST kappa1 was reported as a specific mitochondrial GST.The R2 values of regression ranged between values of about 0.86 and 0.98,which were acceptable for the quantification.Based on the measurement of the GST abundances in liver mitochondria of normal and diabetic mice,the four GSTs,alpha3,kappa1,mu1 and zeta1,were found to be almost comparable between the two sets of animals,whereas,lower GST pi1 was detected in the diabetic mice compared with normal ones,the signal of Western blotting in control and db/ db diabetic mice liver mitochondria is 134.61 ± 53.84vs 99.74 ± 46.2,with P < 0.05.CONCLUSION:Our results indicate that GSTs exist widely in mitochondria and its abundances of mitochondrial GSTs might be tissue-dependent and disease-related.

  5. Glutathione S-transferase activity in follicular fluid from women undergoing ovarian stimulation: role in maturation.

    Science.gov (United States)

    Meijide, Susana; Hernández, M Luisa; Navarro, Rosaura; Larreategui, Zaloa; Ferrando, Marcos; Ruiz-Sanz, José Ignacio; Ruiz-Larrea, M Begoña

    2014-10-01

    Female infertility involves an emotional impact for the woman, often leading to a state of anxiety and low self-esteem. The assisted reproduction techniques (ART) are used to overcome the problem of infertility. In a first step of the in vitro fertilization therapy women are subjected to an ovarian stimulation protocol to obtain mature oocytes, which will result in competent oocytes necessary for fertilization to occur. Ovarian stimulation, however, subjects the women to a high physical and psychological stress, thus being essential to improve ART and to find biomarkers of dysfunction and fertility. GSH is an important antioxidant, and is also used in detoxification reactions, catalysed by glutathione S-transferases (GST). In the present work, we have investigated the involvement of GST in follicular maturation. Patients with fertility problems and oocyte donors were recruited for the study. From each woman follicles at two stages of maturation were extracted at the preovulatory stage. Follicular fluid was separated from the oocyte by centrifugation and used as the enzyme source. GST activity was determined based on its conjugation with 3,4-dichloronitrobenzene and the assay was adapted to a 96-well microplate reader. The absorbance was represented against the incubation time and the curves were adjusted to linearity (R(2)>0.990). Results showed that in both donors and patients GST activity was significantly lower in mature oocytes compared to small ones. These results suggest that GST may play a role in the follicle maturation by detoxifying xenobiotics, thus contributing to the normal development of the oocyte. Supported by FIS/FEDER (PI11/02559), Gobierno Vasco (Dep. Educación, Universiades e Investigación, IT687-13), and UPV/EHU (CLUMBER UFI11/20 and PES13/58). The work was approved by the Ethics Committee of the UPV/EHU (CEISH/96/2011/RUIZLARREA), and performed according to the UPV/EHU and IVI-Bilbao agreement (Ref. 2012/01). PMID:26461371

  6. Chemical Reactivity Window Determines Prodrug Efficiency toward Glutathione Transferase Overexpressing Cancer Cells.

    Science.gov (United States)

    van Gisbergen, Marike W; Cebula, Marcus; Zhang, Jie; Ottosson-Wadlund, Astrid; Dubois, Ludwig; Lambin, Philippe; Tew, Kenneth D; Townsend, Danyelle M; Haenen, Guido R M M; Drittij-Reijnders, Marie-José; Saneyoshi, Hisao; Araki, Mika; Shishido, Yuko; Ito, Yoshihiro; Arnér, Elias S J; Abe, Hiroshi; Morgenstern, Ralf; Johansson, Katarina

    2016-06-01

    Glutathione transferases (GSTs) are often overexpressed in tumors and frequently correlated to bad prognosis and resistance against a number of different anticancer drugs. To selectively target these cells and to overcome this resistance we previously have developed prodrugs that are derivatives of existing anticancer drugs (e.g., doxorubicin) incorporating a sulfonamide moiety. When cleaved by GSTs, the prodrug releases the cytostatic moiety predominantly in GST overexpressing cells, thus sparing normal cells with moderate enzyme levels. By modifying the sulfonamide it is possible to control the rate of drug release and specifically target different GSTs. Here we show that the newly synthesized compounds, 4-acetyl-2-nitro-benzenesulfonyl etoposide (ANS-etoposide) and 4-acetyl-2-nitro-benzenesulfonyl doxorubicin (ANS-DOX), function as prodrugs for GSTA1 and MGST1 overexpressing cell lines. ANS-DOX, in particular, showed a desirable cytotoxic profile by inducing toxicity and DNA damage in a GST-dependent manner compared to control cells. Its moderate conversion of 500 nmol/min/mg, as catalyzed by GSTA1, seems hereby essential since the more reactive 2,4-dinitrobenzenesulfonyl doxorubicin (DNS-DOX) (14000 nmol/min/mg) did not display a preference for GSTA1 overexpressing cells. DNS-DOX, however, effectively killed GSTP1 (20 nmol/min/mg) and MGST1 (450 nmol/min/mg) overexpressing cells as did the less reactive 4-mononitrobenzenesulfonyl doxorubicin (MNS-DOX) in a MGST1-dependent manner (1.5 nmol/min/mg) as shown previously. Furthermore, we show that the mechanism of these prodrugs involves a reduction in GSH levels as well as inhibition of the redox regulatory enzyme thioredoxin reductase 1 (TrxR1) by virtue of their electrophilic sulfonamide moiety. TrxR1 is upregulated in many tumors and associated with resistance to chemotherapy and poor patient prognosis. Additionally, the prodrugs potentially acted as a general shuttle system for DOX, by overcoming resistance

  7. Proteomic and immunochemical characterization of glutathione transferase as a new allergen of the nematode Ascaris lumbricoides.

    Science.gov (United States)

    Acevedo, Nathalie; Mohr, Jens; Zakzuk, Josefina; Samonig, Martin; Briza, Peter; Erler, Anja; Pomés, Anna; Huber, Christian G; Ferreira, Fatima; Caraballo, Luis

    2013-01-01

    Helminth infections and allergy have evolutionary and clinical links. Infection with the nematode Ascaris lumbricoides induces IgE against several molecules including invertebrate pan-allergens. These antibodies influence the pathogenesis and diagnosis of allergy; therefore, studying parasitic and non-parasitic allergens is essential to understand both helminth immunity and allergy. Glutathione transferases (GSTs) from cockroach and house dust mites are clinically relevant allergens and comparative studies between them and the GST from A. lumbricoides (GSTA) are necessary to evaluate their allergenicity. We sought to analyze the allergenic potential of GSTA in connection with the IgE response to non-parasitic GSTs. IgE to purified GSTs from Ascaris (nGSTA and rGSTA), house dust mites (rDer p 8, nBlo t 8 and rBlo t 8), and cockroach (rBla g 5) was measured by ELISA in subjects from Cartagena, Colombia. Also, multidimensional proteomic approaches were used to study the extract of A. lumbricoides and investigate the existence of GST isoforms. We found that among asthmatics, the strength of IgE levels to GSTA was significantly higher than to mite and cockroach GSTs, and there was a strong positive correlation between IgE levels to these molecules. Specific IgE to GSTA was found in 13.2% of controls and 19.5% of asthmatics. In addition nGSTA induced wheal and flare in skin of sensitized asthmatics indicating that it might be of clinical relevance for some patients. Frequency and IgE levels to GSTA were higher in childhood and declined with age. At least six GST isoforms in A. lumbricoides bind human IgE. Four isoforms were the most abundant and several amino acid substitutions were found, mainly on the N-terminal domain. In conclusion, a new allergenic component of Ascaris has been discovered; it could have clinical impact in allergic patients and influence the diagnosis of mite and cockroach allergy in tropical environments.

  8. Genetic polymorphisms in glutathione S-transferase T1 affect the surgical outcome of varicocelectomies in infertile patients

    Institute of Scientific and Technical Information of China (English)

    Kentaro Ichioka; Kanji Nagahama; Kazutoshi Okubo; Takeshi Soda; Osamu Ogawa; Hiroyuki Nishiyama

    2009-01-01

    Glutathione S-transferases (GSTs), superoxide dismutase 2 (SOD2) and NAD(P)H:quinone oxidoreductase 1 (NQO1) are anti-oxidant enzyme genes. Polymorphisms of GSTs, SOD2 and NQO1 have been reported to influence individual susceptibility to various diseases. In an earlier study, we obtained preliminary findings that a subset of glutathione S-transferase T1 (GSTT1)-wt patients with varicocele may exhibit good response to varicocelectomy. In this study, we extended the earlier study to determine the distribution of genotype of each gene in the infertile population and to evaluate whether polymorphism of these genes affects the results of surgical treatment of varicocele. We analyzed 72 infertile varicocele patients, 202 infertile patients without varicocele and 101 male controls. Genotypes of GSTs were determined by polymerase chain reaction (PCR). Genotyping of SOD2 and NQO1 was performed using the PCR-restriction fragment length polymorphism (PCR-RFLP) method. A significantly better response to varicocelectomy was found in patients with the GSTTI-wt genotype (63.2%) and NQO1-Ser/Ser genotype (80.0%) than in those with GSTT1-null genotype (35.3%) and NQO1-Pro/Pro or NQO1-Pro/Ser genotype (45.2%), respectively. The frequencies of glutathione S-transferase M1/T1, SOD2 and NQO1 genotypes did not differ significantly among the varicocele patients, idiopathic infertile patients and male controls. GSTT1 genotype is associated with improvement of semen parameters after varicocelectomy. As the number of patients with NQO1-Ser/Ser genotype was not sufficient to reach definite conclusions, the association of NQO1 genotype with varicoceleetomy requires further investigation.

  9. Comparative study on glutathione transferases of rat brain and testis under the stress of phenobarbitol and β-methylcholanthrene

    Institute of Scientific and Technical Information of China (English)

    THYAGARAJU K.; HEMAVATHI B.; VASUNDHARA K.; RAO A.D.; DEVI K.N.

    2005-01-01

    A comparative study was made on the tissue specific expression of glutathione transferases (GST) in brain and testis after exposure of rat to phenobarbitol (PB) and 3-methylcholanthrene (MC). Glutathione transferases, a family of multifunctional proteins are involved in intracellular transport processes and in detoxication of electrophilic xenobiotics by catalyzing reactions such as conjugation, isomerization, reduction and thiolysis. On purification, the yield of GST proteins by affinity chromatography was 39% in testis and 32% in brain. The affinity purified testis GSTs were resolved by chromatofocusing into six anionic and four cationic isozymes, and in brain glutathione transferases were resolved into four anionic and three cationic isozymes, suggesting the presence of multiple isozymes with Yc, Yb, Y3 and Yδ in both of them. In testis and brain, these isozymes at identical pI values showed variable functions with a battery of substrates and the cationic isozymes of brain and testis showed identical properties in CHP (cumene hydroperoxide) at pH values of above 7.0. Substrate specificity studies and immunoblot analysis of testis and brain proteins revealed that they play a predominant role in the detoxication of phenobarbitol or 3-methylcholanthrene. Expression of the isozymes in testis and brain on exposure to PB and MC indicated elevated subunit variation. In both testis and brain, Yδ ofπclass was expressed on PB treatment and Yc of α class and Y3 of μ class was expressed in MC treated testis and only Yc was predominantly expressed in MC treated brain. Thus these subunits expression is considered as markers for carcinogenesis and specific to chemical toxicity under phenobarbitol and 13-methylcholanthrene stress.

  10. Glutathione S-transferases gene polymorphisms and risk of male idiopathic infertility: a systematic review and meta-analysis.

    Science.gov (United States)

    Li, Xin; Pan, Jinhong; Liu, Qigui; Xiong, Enqing; Chen, Zhiwen; Zhou, Zhansong; Su, Yongping; Lu, Gensheng

    2013-03-01

    The Glutathione S-transferases (GSTs) polymorphisms have been implicated in susceptibility to male idiopathic infertility, but study results are still controversial. To investigate the genetic associations between GSTs polymorphisms and risk of male idiopathic infertility, a systematic review and meta-analysis were performed. Meta-analysis was performed by pooling odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI) form studies in electronic databases up to March 16, 2012. Glutathione S-transferase M 1 (GSTM1) null genotype, Glutathione S-transferase T 1 (GSTT1) null genotype, and dual null genotype of GSTM1/GSTT1 were analyzed independently. 14 eligible studies with a total of 1,845 idiopathic infertility males and 1,729 controls were included. There were 13 studies on GSTM1 polymorphism, 10 ones on GSTT1 polymorphism and 5 ones on GSTM1-GSTT1 interaction analysis. Meta-analyses of total relevant studies showed GSTM1 null genotype was significantly associated with an increased risk of male idiopathic infertility (OR = 1.40, 95 % CI 1.07-1.84, P OR = 0.015). The GSTM1-GSTT1 interaction analysis showed dual null genotype of GSTM1/GSTT1 was also significantly associated with increased risk of male idiopathic infertility (OR = 1.85, 95 % CI 1.07-3.21, P OR = 0.028). Subgroup analyses by ethnicity showed the associations above were still statistically significant in Caucasians (For GSTM1, OR = 1.51, 95 % CI 1.11-2.05, P OR = 0.009; For GSTM1/GSTT1, OR = 2.10, 95 % CI 1.51-2.91, P OR < 0.001). This meta-analysis suggests GSTM1 null genotype contributes to increased risk of male idiopathic infertility in Caucasians, and males with dual null genotype of GSTM1/GSTT1 are particularly susceptible to developing idiopathic infertility.

  11. An Entamoeba histolytica ADP-ribosyl transferase from the diphtheria toxin family modifies the bacterial elongation factor Tu.

    Science.gov (United States)

    Avila, Eva E; Rodriguez, Orlando I; Marquez, Jaqueline A; Berghuis, Albert M

    2016-06-01

    ADP-ribosyl transferases are enzymes involved in the post-translational modification of proteins; they participate in multiple physiological processes, pathogenesis and host-pathogen interactions. Several reports have characterized the functions of these enzymes in viruses, prokaryotes and higher eukaryotes, but few studies have reported ADP-ribosyl transferases in lower eukaryotes, such as parasites. The locus EHI_155600 from Entamoeba histolytica encodes a hypothetical protein that possesses a domain from the ADP-ribosylation superfamily; this protein belongs to the diphtheria toxin family according to a homology model using poly-ADP-ribosyl polymerase 12 (PARP12 or ARTD12) as a template. The recombinant protein expressed in Escherichia coli exhibited in vitro ADP-ribosylation activity that was dependent on the time and temperature. Unlabeled βNAD(+), but not ADP-ribose, competed in the enzymatic reaction using biotin-βNAD(+) as the ADP-ribose donor. The recombinant enzyme, denominated EhToxin-like, auto-ADP-ribosylated and modified an acceptor from E. coli that was identified by MS/MS as the elongation factor Tu (EF-Tu). To the best of our knowledge, this is the first report to identify an ADP-ribosyl transferase from the diphtheria toxin family in a protozoan parasite. The known toxins from this family (i.e., the diphtheria toxin, the Pseudomonas aeruginosa toxin Exo-A, and Cholix from Vibrio cholerae) modify eukaryotic elongation factor two (eEF-2), whereas the amoeba EhToxin-like modified EF-Tu, which is another elongation factor involved in protein synthesis in bacteria and mitochondria. PMID:27234208

  12. Alterations at the peptidyl transferase centre of the ribosome induced by the synergistic action of the streptogramins dalfopristin and quinupristin

    Directory of Open Access Journals (Sweden)

    Fucini Paola

    2004-04-01

    Full Text Available Abstract Background The bacterial ribosome is a primary target of several classes of antibiotics. Investigation of the structure of the ribosomal subunits in complex with different antibiotics can reveal the mode of inhibition of ribosomal protein synthesis. Analysis of the interactions between antibiotics and the ribosome permits investigation of the specific effect of modifications leading to antimicrobial resistances. Streptogramins are unique among the ribosome-targeting antibiotics because they consist of two components, streptogramins A and B, which act synergistically. Each compound alone exhibits a weak bacteriostatic activity, whereas the combination can act bactericidal. The streptogramins A display a prolonged activity that even persists after removal of the drug. However, the mode of activity of the streptogramins has not yet been fully elucidated, despite a plethora of biochemical and structural data. Results The investigation of the crystal structure of the 50S ribosomal subunit from Deinococcus radiodurans in complex with the clinically relevant streptogramins quinupristin and dalfopristin reveals their unique inhibitory mechanism. Quinupristin, a streptogramin B compound, binds in the ribosomal exit tunnel in a similar manner and position as the macrolides, suggesting a similar inhibitory mechanism, namely blockage of the ribosomal tunnel. Dalfopristin, the corresponding streptogramin A compound, binds close to quinupristin directly within the peptidyl transferase centre affecting both A- and P-site occupation by tRNA molecules. Conclusions The crystal structure indicates that the synergistic effect derives from direct interaction between both compounds and shared contacts with a single nucleotide, A2062. Upon binding of the streptogramins, the peptidyl transferase centre undergoes a significant conformational transition, which leads to a stable, non-productive orientation of the universally conserved U2585. Mutations of this r

  13. Phosphoethanolamine Transferase LptA in Haemophilus ducreyi Modifies Lipid A and Contributes to Human Defensin Resistance In Vitro.

    Directory of Open Access Journals (Sweden)

    Michael P Trombley

    Full Text Available Haemophilus ducreyi resists the cytotoxic effects of human antimicrobial peptides (APs, including α-defensins, β-defensins, and the cathelicidin LL-37. Resistance to LL-37, mediated by the sensitive to antimicrobial peptide (Sap transporter, is required for H. ducreyi virulence in humans. Cationic APs are attracted to the negatively charged bacterial cell surface. In other gram-negative bacteria, modification of lipopolysaccharide or lipooligosaccharide (LOS by the addition of positively charged moieties, such as phosphoethanolamine (PEA, confers AP resistance by means of electrostatic repulsion. H. ducreyi LOS has PEA modifications at two sites, and we identified three genes (lptA, ptdA, and ptdB in H. ducreyi with homology to a family of bacterial PEA transferases. We generated non-polar, unmarked mutants with deletions in one, two, or all three putative PEA transferase genes. The triple mutant was significantly more susceptible to both α- and β-defensins; complementation of all three genes restored parental levels of AP resistance. Deletion of all three PEA transferase genes also resulted in a significant increase in the negativity of the mutant cell surface. Mass spectrometric analysis revealed that LptA was required for PEA modification of lipid A; PtdA and PtdB did not affect PEA modification of LOS. In human inoculation experiments, the triple mutant was as virulent as its parent strain. While this is the first identified mechanism of resistance to α-defensins in H. ducreyi, our in vivo data suggest that resistance to cathelicidin LL-37 may be more important than defensin resistance to H. ducreyi pathogenesis.

  14. Characterization and heterospecific expression of cDNA clones of genes in the maize GSH S-transferase multigene family.

    OpenAIRE

    Grove, G; Zarlengo, R P; Timmerman, K P; Li, N Q; Tam, M F; Tu, C P

    1988-01-01

    We have isolated from a constructed lambda gt11 expression library two classes of cDNA clones encoding the entire sequence of the maize GSH S-transferases GST I and GST III. Expression of a full-length GST I cDNA in E. coli resulted in the synthesis of enzymatically active maize GST I that is immunologically indistinguishable from the native GST I. Another GST I cDNA with a truncated N-terminal sequence is also active in heterospecific expression. Our GST III cDNA sequence differs from the ve...

  15. Glutathione-S-Transferase: A Minor Allergen in Birch Pollen due to Limited Release from Hydrated Pollen

    OpenAIRE

    Stephan Deifl; Christian Zwicker; Eva Vejvar; Claudia Kitzmüller; Gabriele Gadermaier; Birgit Nagl; Susanne Vrtala; Peter Briza; Zlabinger, Gerhard J.; Beatrice Jahn-Schmid; Fatima Ferreira; Barbara Bohle

    2014-01-01

    Background Recently, a protein homologous to glutathione-S-transferases (GST) was detected in prominent amounts in birch pollen by proteomic profiling. As members of the GST family are relevant allergens in mites, cockroach and fungi we investigated the allergenic relevance of GST from birch (bGST). Methodology bGST was expressed in Escherichia coli, purified and characterized by mass spectrometry. Sera from 217 birch pollen-allergic patients were tested for IgE-reactivity to bGST by ELISA. T...

  16. Cloning and expression of a cDNA encoding a maize glutathione-S-transferase in E. coli.

    OpenAIRE

    Moore, R. E.; Davies, M S; O'Connell, K M; Harding, E I; Wiegand, R C; Tiemeier, D C

    1986-01-01

    The isolation and characterization of a family of maize glutathione-S-transferases (GST's) has been described previously. These enzymes are designated GSTs I, II and III based on size, substrate specificity and responsiveness to safeners. GST III has been shown to act on the herbicide alachlor as well as the commonly used substrate 1-chloro-2,4-dinitrobenzene (CDNB). Clones were isolated from a maize cDNA library in lambda gt10. Three clones contained the entire coding region for GST III. The...

  17. Inhibition of the ribosomal peptidyl transferase reaction by the mycarose moiety of the antibiotics carbomycin, spiramycin and tylosin

    DEFF Research Database (Denmark)

    Poulsen, S M; Kofoed, C; Vester, B

    2000-01-01

    investigated by chemical probing of domains II and V of 23 S rRNA. The common binding site is around position A2058, while effects on U2506 depend on the presence of the mycarose sugar. Also, protection at position A752 indicates that a mycinose moiety at position 14 in 16-member ring macrolides interact...... transferase reaction bind to the ribosomes concurrently with hygromycin A. Data are presented to argue that a disaccharide at position 5 in the lactone ring of macrolides is essential for inhibition of peptide bond formation and that the mycarose moiety is placed near the conserved U2506 in the central loop...

  18. Does occupational exposure to solvents and pesticides in association with glutathione S-transferase A1, M1, P1, and T1 polymorphisms increase the risk of bladder cancer? The Belgrade case-control study.

    Directory of Open Access Journals (Sweden)

    Marija G Matic

    Full Text Available OBJECTIVE: We investigated the role of the glutathione S-transferase A1, M1, P1 and T1 gene polymorphisms and potential effect modification by occupational exposure to different chemicals in Serbian bladder cancer male patients. PATIENTS AND METHODS: A hospital-based case-control study of bladder cancer in men comprised 143 histologically confirmed cases and 114 age-matched male controls. Deletion polymorphism of glutathione S-transferase M1 and T1 was identified by polymerase chain reaction method. Single nucleotide polymorphism of glutathione S-transferase A1 and P1 was identified by restriction fragment length polymorphism method. As a measure of effect size, odds ratio (OR with corresponding 95% confidence interval (95%CI was calculated. RESULTS: The glutathione S-transferase A1, T1 and P1 genotypes did not contribute independently toward the risk of bladder cancer, while the glutathione S-transferase M1-null genotype was overrepresented among cases (OR = 2.1, 95% CI = 1.1-4.2, p = 0.032. The most pronounced effect regarding occupational exposure to solvents and glutathione S-transferase genotype on bladder cancer risk was observed for the low activity glutathione S-transferase A1 genotype (OR = 9.2, 95% CI = 2.4-34.7, p = 0.001. The glutathione S-transferase M1-null genotype also enhanced the risk of bladder cancer among subjects exposed to solvents (OR = 6,5, 95% CI = 2.1-19.7, p = 0.001. The risk of bladder cancer development was 5.3-fold elevated among glutathione S-transferase T1-active patients exposed to solvents in comparison with glutathione S-transferase T1-active unexposed patients (95% CI = 1.9-15.1, p = 0.002. Moreover, men with glutathione S-transferase T1-active genotype exposed to pesticides exhibited 4.5 times higher risk in comparison with unexposed glutathione S-transferase T1-active subjects (95% CI = 0.9-22.5, p = 0.067. CONCLUSION: Null or low-activity genotypes of the

  19. 低聚糖阿魏酸酯改善妊娠期糖尿病代谢控制及其肝氧化生物标记物的研究%Improved metabolic control and hepatic oxidative biomarkers of gestational diabetes mellitus with the use of feruloyl oligosaccharides

    Institute of Scientific and Technical Information of China (English)

    秦庆新; 肖正华; 谢晓斌

    2014-01-01

    目的:探讨低聚糖阿魏酸酯( CFOs)在由链脲佐菌素诱导的1型糖尿病怀孕大鼠体内的降血糖和抗氧化作用。方法:取40只大鼠做实验,共分五组(每组8只):(1)未交配过的糖尿病鼠为对照组;(2)交配过的非糖尿病鼠为对照组;(3)交配过的糖尿病鼠为对照组;(4)未交配过的糖尿病鼠为治疗组;(5)交配过的糖尿病鼠为治疗组。治疗组在大鼠交配前3 d开始,连续15 d给大鼠喂饲玉米低聚糖阿魏酸酯植物提取物(25 mg/kg)。对照组动物则只接受溶媒处理(2.5 mL/kg)。在交配后的第14天,处死大鼠,从下腔静脉采集母体血液,做ELISA检测。交配过的大鼠应解剖其子宫以搜寻任何可能存在的胎儿。每只大鼠的肝脏都被迅速切除,用Jamall和Smith的检测方法来确定组织样本中脂质过氧化物的水平。结果:不考虑怀孕因素,低聚糖阿魏酸酯的使用可降低血糖值( P0.05)。实验动物被诱导患糖尿病后,再用低聚糖阿魏酸酯进行治疗,其谷胱甘肽水平的平均值有所下降( P0.05) . After the experimental animals with induced diabetes treated by feruloyl oligosaccharides, their mean level of glutathione decreased (P<0.05). There were statistical significance of the levels of thiobarbituric acid-reactive substances and the levels of glutathione between the rat livers of diabetic pregnant treatment group and pregnant control group ( P<0.05) . Conclusion:Feruloyl oligosaccharides could decrease the concentration of blood glucose and increase the concentration of serum insulin in pregnant and non-pregnant diabetic rats. And the rise of lipid peroxidation and the decline of glutathione related with liver reversed.

  20. A simple colorimetric assay for specific detection of glutathione-S transferase activity associated with DDT resistance in mosquitoes.

    Directory of Open Access Journals (Sweden)

    Evangelia Morou

    Full Text Available BACKGROUND: Insecticide-based methods represent the most effective means of blocking the transmission of vector borne diseases. However, insecticide resistance poses a serious threat and there is a need for tools, such as diagnostic tests for resistance detection, that will improve the sustainability of control interventions. The development of such tools for metabolism-based resistance in mosquito vectors lags behind those for target site resistance mutations. METHODOLOGY/PRINCIPAL FINDINGS: We have developed and validated a simple colorimetric assay for the detection of Epsilon class Glutathione transferases (GST-based DDT resistance in mosquito species, such as Aedes aegypti, the major vector of dengue and yellow fever worldwide. The colorimetric assay is based on the specific alkyl transferase activity of Epsilon GSTs for the haloalkene substrate iodoethane, which produces a dark blue colour highly correlated with AaGSTE2-2-overexpression in individual mosquitoes. The colour can be measured visually and spectrophotometrically. CONCLUSIONS/SIGNIFICANCE: The novel assay is substantially more sensitive compared to the gold standard CDNB assay and allows the discrimination of moderate resistance phenotypes. We anticipate that it will have direct application in routine vector monitoring as a resistance indicator and possibly an important impact on disease vector control.

  1. A cytosolic glutathione s-transferase, GST-theta from freshwater prawn Macrobrachium rosenbergii: molecular and biochemical properties.

    Science.gov (United States)

    Arockiaraj, Jesu; Gnanam, Annie J; Palanisamy, Rajesh; Bhatt, Prasanth; Kumaresan, Venkatesh; Chaurasia, Mukesh Kumar; Pasupuleti, Mukesh; Ramaswamy, Harikrishnan; Arasu, Abirami; Sathyamoorthi, Akila

    2014-08-10

    Glutathione S-transferases play an important role in cellular detoxification and may have evolved to protect cells against reactive oxygen metabolites. In this study, we report the molecular characterization of glutathione s-transferase-theta (GST-θ) from freshwater prawn Macrobrachium rosenbergii. A full length cDNA of GSTT (1417 base pairs) was isolated and characterized bioinformatically. Exposure to virus (white spot syndrome baculovirus or M. rosenbergii nodovirus), bacteria (Aeromonas hydrophila or Vibrio harveyi) or heavy metals (cadmium or lead) significantly increased the expression of GSTT (P<0.05) in hepatopancreas. Recombinant GST-θ with monochlorobimane substrate had an optimum activity at pH7.5 and 35 °C. Furthermore recombinant GST-θ activity was abolished by the denaturants triton X-100, Gua-HCl, Gua-thiocyanate, SDS and urea in a dose-dependent manner. Overall, the results suggest a potential role for M. rosenbergii GST-θ in detoxification and possibly conferring immune protection.

  2. Lipoprotein N-acyl transferase (Lnt1) is dispensable for protein O-mannosylation by Streptomyces coelicolor.

    Science.gov (United States)

    Córdova-Dávalos, Laura Elena; Espitia, Clara; González-Cerón, Gabriela; Arreguín-Espinosa, Roberto; Soberón-Chávez, Gloria; Servín-González, Luis

    2014-01-01

    A protein glycosylation system related to that for protein mannosylation in yeast is present in many actinomycetes. This system involves polyprenyl phosphate mannose synthase (Ppm), protein mannosyl transferase (Pmt), and lipoprotein N-acyl transferase (Lnt). In this study, we obtained a series of mutants in the ppm (sco1423), lnt1 (sco1014), and pmt (sco3154) genes of Streptomyces coelicolor, which encode Ppm, Lnt1, and Pmt, to analyze their requirement for glycosylation of the heterologously expressed Apa glycoprotein of Mycobacterium tuberculosis. The results show that both Ppm and Pmt were required for Apa glycosylation, but that Lnt1 was dispensable for both Apa and the bacteriophage φC31 receptor glycosylation. A bacterial two-hybrid assay revealed that contrary to M. tuberculosis, Lnt1 of S. coelicolor does not interact with Ppm. The D2 catalytic domain of M. tuberculosisPpm was sufficient for complementation of an S. coelicolor double mutant lacking Lnt1 and Ppm, both for Apa glycosylation and for glycosylation of φC31 receptor. On the other hand, M. tuberculosisPmt was not active in S. coelicolor, even when correctly localized to the cytoplasmic membrane, showing fundamental differences in the requirements for Pmt activity in these two species.

  3. Crystallization and preliminary X-ray diffraction analysis of a glutathione S-transferase from Xylella fastidiosa

    International Nuclear Information System (INIS)

    Glutathione S-transferase from X. fastidiosa (xfGST) has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.23 Å. Glutathione S-transferases (GSTs) form a group of multifunctional isoenzymes that catalyze the glutathione-dependent conjugation and reduction reactions involved in the cellular detoxification of xenobiotic and endobiotic compounds. GST from Xylella fastidiosa (xfGST) was overexpressed in Escherichia coli and purified by conventional affinity chromatography. In this study, the crystallization and preliminary X-ray analysis of xfGST is described. The purified protein was crystallized by the vapour-diffusion method, producing crystals that belonged to the triclinic space group P1. The unit-cell parameters were a = 47.73, b = 87.73, c = 90.74 Å, α = 63.45, β = 80.66, γ = 94.55°. xfGST crystals diffracted to 2.23 Å resolution on a rotating-anode X-ray source

  4. Acute cadmium intoxication induces alpha-class glutathione S-transferase protein synthesis and enzyme activity in rat liver

    International Nuclear Information System (INIS)

    Acute cadmium intoxication affects glutathione S-transferase (GST) in rat liver. It has been found that 24 h after i.p. cadmium administration to rats, at a dose of 2.5 mg CdCl2 kg-1 body weight, the activity of this enzyme in liver cytosol increased by 40%. A less stimulatory effect persisted till 48 h and thereafter the enzyme activity normalized. Since, GST isoenzymes belong to different classes in mammalian tissues, we used quantitative immunoassays to verify which family of GST isoenzymes is influenced by this intoxication. Only alpha-class glutathione S-transferase (α-GST) proteins were detected in rat liver cytosol and their level increased by about 25%, 24 h after cadmium treatment. No pi-GST isoforms were found in liver cytosol from either normal or cadmium-treated rats. Co-administration of actinomycin D with cadmium normalized both the protein level and the activity of α-GST, suggesting that some effect occurs on enzyme transcription of these isoenzymes by this metal. On the other hand, it seems unlikely that the stimulatory effect is due to the high level of peroxides caused by lipid peroxidation, since Vitamin E administration strongly reduced the TBARS level, but did not cause any GST activity decrease

  5. Glutathione transferase (GST) as a candidate molecular-based biomarker for soil toxin exposure in the earthworm Lumbricus rubellus

    Energy Technology Data Exchange (ETDEWEB)

    LaCourse, E. James, E-mail: james.la-course@liverpool.ac.u [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); Hernandez-Viadel, Mariluz; Jefferies, James R. [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); Svendsen, Claus; Spurgeon, David J. [Centre for Ecology and Hydrology, Huntingdon PE28 2LS (United Kingdom); Barrett, John [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); John Morgan, A.; Kille, Peter [Biosciences, University of Cardiff, Cardiff CF10 3TL (United Kingdom); Brophy, Peter M. [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom)

    2009-08-15

    The earthworm Lumbricus rubellus (Hoffmeister, 1843) is a terrestrial pollution sentinel. Enzyme activity and transcription of phase II detoxification superfamily glutathione transferases (GST) is known to respond in earthworms after soil toxin exposure, suggesting GST as a candidate molecular-based pollution biomarker. This study combined sub-proteomics, bioinformatics and biochemical assay to characterise the L. rubellus GST complement as pre-requisite to initialise assessment of the applicability of GST as a biomarker. L. rubellus possesses a range of GSTs related to known classes, with evidence of tissue-specific synthesis. Two affinity-purified GSTs dominating GST protein synthesis (Sigma and Pi class) were cloned, expressed and characterised for enzyme activity with various substrates. Electrospray ionisation mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) following SDS-PAGE were superior in retaining subunit stability relative to two-dimensional gel electrophoresis (2-DE). This study provides greater understanding of Phase II detoxification GST superfamily status of an important environmental pollution sentinel organism. - This study currently provides the most comprehensive view of the Phase II detoxification enzyme superfamily of glutathione transferases within the important environmental pollution sentinel earthworm Lumbricus rubellus.

  6. Crystallization and preliminary X-ray diffraction analysis of a glutathione S-transferase from Xylella fastidiosa

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Wanius, E-mail: wanius@if.sc.usp.br [Laboratório de Biofísica Molecular ‘Sérgio Mascarenhas’, Instituto de Física de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Travensolo, Regiane F. [Grupo de Bioanalítica, Microfabricação e Separações, Instituto de Química de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Rodrigues, Nathalia C.; Muniz, João R. C. [Laboratório de Biofísica Molecular ‘Sérgio Mascarenhas’, Instituto de Física de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Caruso, Célia S. [Grupo de Bioanalítica, Microfabricação e Separações, Instituto de Química de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Lemos, Eliana G. M. [Laboratório de Bioquímica de Microrganismos e de Plantas, Departamento de Tecnologia, UNESP, Jaboticabal (Brazil); Araujo, Ana Paula U. [Laboratório de Biofísica Molecular ‘Sérgio Mascarenhas’, Instituto de Física de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Carrilho, Emanuel, E-mail: wanius@if.sc.usp.br [Grupo de Bioanalítica, Microfabricação e Separações, Instituto de Química de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil); Laboratório de Biofísica Molecular ‘Sérgio Mascarenhas’, Instituto de Física de São Carlos, Universidade de São Paulo (USP), São Carlos (Brazil)

    2008-02-01

    Glutathione S-transferase from X. fastidiosa (xfGST) has been overexpressed in E. coli, purified and crystallized. Diffraction data were collected to 2.23 Å. Glutathione S-transferases (GSTs) form a group of multifunctional isoenzymes that catalyze the glutathione-dependent conjugation and reduction reactions involved in the cellular detoxification of xenobiotic and endobiotic compounds. GST from Xylella fastidiosa (xfGST) was overexpressed in Escherichia coli and purified by conventional affinity chromatography. In this study, the crystallization and preliminary X-ray analysis of xfGST is described. The purified protein was crystallized by the vapour-diffusion method, producing crystals that belonged to the triclinic space group P1. The unit-cell parameters were a = 47.73, b = 87.73, c = 90.74 Å, α = 63.45, β = 80.66, γ = 94.55°. xfGST crystals diffracted to 2.23 Å resolution on a rotating-anode X-ray source.

  7. In-house preparation of hydrogels for batch affinity purification of glutathione S-transferase tagged recombinant proteins

    Directory of Open Access Journals (Sweden)

    Buhrman Jason S

    2012-09-01

    Full Text Available Abstract Background Many branches of biomedical research find use for pure recombinant proteins for direct application or to study other molecules and pathways. Glutathione affinity purification is commonly used to isolate and purify glutathione S-transferase (GST-tagged fusion proteins from total cellular proteins in lysates. Although GST affinity materials are commercially available as glutathione immobilized on beaded agarose resins, few simple options for in-house production of those systems exist. Herein, we describe a novel method for the purification of GST-tagged recombinant proteins. Results Glutathione was conjugated to low molecular weight poly(ethylene glycol diacrylate (PEGDA via thiol-ene “click” chemistry. With our in-house prepared PEGDA:glutathione (PEGDA:GSH homogenates, we were able to purify a glutathione S-transferase (GST green fluorescent protein (GFP fusion protein (GST-GFP from the soluble fraction of E. coli lysate. Further, microspheres were formed from the PEGDA:GSH hydrogels and improved protein binding to a level comparable to purchased GSH-agarose beads. Conclusions GSH containing polymers might find use as in-house methods of protein purification. They exhibited similar ability to purify GST tagged proteins as purchased GSH agarose beads.

  8. The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations.

    LENUS (Irish Health Repository)

    Flanagan, J M

    2010-02-01

    Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

  9. Epsilon glutathione transferases possess a unique class-conserved subunit interface motif that directly interacts with glutathione in the active site.

    Science.gov (United States)

    Wongsantichon, Jantana; Robinson, Robert C; Ketterman, Albert J

    2015-10-20

    Epsilon class glutathione transferases (GSTs) have been shown to contribute significantly to insecticide resistance. We report a new Epsilon class protein crystal structure from Drosophila melanogaster for the glutathione transferase DmGSTE6. The structure reveals a novel Epsilon clasp motif that is conserved across hundreds of millions of years of evolution of the insect Diptera order. This histidine-serine motif lies in the subunit interface and appears to contribute to quaternary stability as well as directly connecting the two glutathiones in the active sites of this dimeric enzyme.

  10. The role of the glutathione S-transferase genes GSTT1, GSTM1, and GSTP1 in acetaminophen-poisoned patients

    DEFF Research Database (Denmark)

    Buchard, Anders; Eefsen, Martin; Semb, Synne;

    2012-01-01

    The aim of this study was to assess if genetic variants in the glutathione-S-transferase genes GST-T1, M1, and P1 reflect risk factors in acetaminophen (APAP)-poisoned patients assessed by investigation of the relation to prothrombin time (PT), which is a sensitive marker of survival in these pat......The aim of this study was to assess if genetic variants in the glutathione-S-transferase genes GST-T1, M1, and P1 reflect risk factors in acetaminophen (APAP)-poisoned patients assessed by investigation of the relation to prothrombin time (PT), which is a sensitive marker of survival...

  11. STUDY OF THE DELETION MUTATION OF GLUTATHIONE S TRANSFERASE M1 GENE AND ITS ROLE IN SUSCEPTIBILITY TO HEPATOCELLULAR CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    MA; Yun

    2001-01-01

    [1]Guengerich FP, Shimada T, Raney KD, et al. Elucidation of catalytic specificities of human cytochrome P450 and glutathione S-transferase enzymes and relevance to molecular epidemiology [J]. Envir Health Perspectives 1992; 98:75.[2]Salagoric J, Kalina I, Stubna J, et al. Genetic polymorphism of glutathione S-transferases M1 and T1 as a risk factor in lung and bladder cancers [J]. Neoplasma 1998; 45:312.[3]Comstock KE, Sanderson BJ.S, Claflin SG, et al. GST1 gene deletion determined by polymerase chain reaction [J]. Nucleic Acids Research 1990; 18:3670.[4]Ma Yun, Deng Zhuolin, Le Chenyi, et al. The comparative study on mutational hot spot of p53 gene in hepatocellular carcinoma from AFB1 high and low risk area in Guangxi [J]. J Clin Exp Pthol 1997; 13:302.[5]McGlyNN KA, Rosvold EA, Lustbader ED, et al. Susceptibility to hepatocellular carcinoma is associated with genetic variation in the enzymatic detoxification of aflatoxin B1 [J]. Proc Natl Acad Sci USA 1995; 92:2384..[6]Chen CJ, Yu MW, Liaw YF. Epidemiological characteristics and factors of hepatocellular carcinoma [J]. J Gastroenterol Hepatol 1997; 12:294.[7]Hu Ying, Shen Fumin. Association between GSTM1 gene polymorphism of primary hepatocellular carcinoma and mutation of p53 codon 249 [J]. Chin J Med Genet 1997; 14:76.[8]Hsieh LL, Huang RC, Yu MW, et al. L-myc, GSTM1 genetic polymorphism and hepatocellular carcinoma risk among hepatitis B carriers [J]. Cancer Lett 1996; 103:171.[9]Dong Chuanhui, Zi Xiaolin, Yu Shunzhang, et al. Relationship between deletion of glutathione S-transferase gene and susceptibility to primary hepatocellular carcinoma [J]. Chin J Public Health 1997; 16:141.[10]Chomarat P, Rice JM, Slagle BL, et al. Hepatitis B virus induced liver injury and altered expression of carcinogen metabolising enzymes: the role of the HBx protein [J]. Toxicol Lett 1998; 28:595.

  12. Identification of the nuclear localisation signal of O-GlcNAc transferase and its nuclear import regulation

    Science.gov (United States)

    Seo, Hyeon Gyu; Kim, Han Byeol; Kang, Min Jueng; Ryum, Joo Hwan; Yi, Eugene C.; Cho, Jin Won

    2016-01-01

    Nucleocytoplasmic O-GlcNAc transferase (OGT) attaches a single GlcNAc to hydroxyl groups of serine and threonine residues. Although the cellular localisation of OGT is important to regulate a variety of cellular processes, the molecular mechanisms regulating the nuclear localisation of OGT is unclear. Here, we characterised three amino acids (DFP; residues 451–453) as the nuclear localisation signal of OGT and demonstrated that this motif mediated the nuclear import of non-diffusible β-galactosidase. OGT bound the importin α5 protein, and this association was abolished when the DFP motif of OGT was mutated or deleted. We also revealed that O-GlcNAcylation of Ser389, which resides in the tetratricopeptide repeats, plays an important role in the nuclear localisation of OGT. Our findings may explain how OGT, which possesses a NLS, exists in the nucleus and cytosol simultaneously. PMID:27713473

  13. Yeast One-hybrid System Used to Identify the Binding Proteins for Rat Glutathione S-transferase P Enhancer I

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To detect the trans-factors specifically binding to the strong enhancer element (GPEI) in the upstream of rat glutathione S-transferase P (GST-P) gene. Methods Yeast one-hybrid system was used to screen rat lung MATCHMAKER cDNA library to identify potential trans-factors that can interact with core sequence of GPEI(cGPEI).Electrophoresis mobility shift assay (EMSA) was used to analyze the binding of transfactors to cGPEI. Results cDNA fragments coding for the C-terminal part of the transcription factor c-Jun and rat adenine nucleotide translocator (ANT) were isolated, The binding of c-Jun and ANT to GPEI core sequence were confirmed. Conclusions Rat c-jun transcriptional factor and ANT may interact with cGPEI. They could play an important role in the induced expression of GST-P gene.

  14. Glutathione S-transferases interact with AMP-activated protein kinase: evidence for S-glutathionylation and activation in vitro.

    Science.gov (United States)

    Klaus, Anna; Zorman, Sarah; Berthier, Alexandre; Polge, Cécile; Ramirez, Sacnicte; Michelland, Sylvie; Sève, Michel; Vertommen, Didier; Rider, Mark; Lentze, Nicolas; Auerbach, Daniel; Schlattner, Uwe

    2013-01-01

    AMP-activated protein kinase (AMPK) is a cellular and whole body energy sensor with manifold functions in regulating energy homeostasis, cell morphology and proliferation in health and disease. Here we apply multiple, complementary in vitro and in vivo interaction assays to identify several isoforms of glutathione S-transferase (GST) as direct AMPK binding partners: Pi-family member rat GSTP1 and Mu-family members rat GSTM1, as well as Schistosoma japonicum GST. GST/AMPK interaction is direct and involves the N-terminal domain of the AMPK β-subunit. Complex formation of the mammalian GSTP1 and -M1 with AMPK leads to their enzymatic activation and in turn facilitates glutathionylation and activation of AMPK in vitro. GST-facilitated S-glutathionylation of AMPK may be involved in rapid, full activation of the kinase under mildly oxidative physiological conditions.

  15. Genetic Polymorphisms Analysis of Glutathione S-transferase M1 and T1 in Children with Acute Lymphoblastic Leukemia

    Institute of Scientific and Technical Information of China (English)

    王军; 张利; 冯建飞; 王宏; 朱绍先; 胡豫; 李玉香

    2004-01-01

    Summary: The relationship between glutathione S-transferases (GSTs) M1, T1 genotype and childhood acute lymphoblastic leukemia (ALL) was investigated. GSTM1 and GSTT1 genotypes in genomic DNA from 67 children with ALL and 146 healthy controls were analyzed by using the multiplex polymerase chain reaction (PCR). The frequencies of GSTM1, M1-T1 null genotypes in ALL children were significantly higher than in the healthy controls (76.12 % versus 52.74 %, OR=2.856, P<0.001;50. 74 % versus 24. 66 %, OR=3. 148, P<0.001, respectively). However,there was no significant relationship between GSTT1 null genotype and ALL of children (61.19 %versus 49.32 %, OR=1. 621, P>0.05). It was suggested that GSTM1 null genotype might be a risk genotype of childhood ALL, while there as no correlation between GSTT1 null genotype and childhood ALL.

  16. Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation

    DEFF Research Database (Denmark)

    Lira-Navarrete, Erandi; de Las Rivas, Matilde; Compañón, Ismael;

    2015-01-01

    Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present...... the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy...... and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity...

  17. Movement of the 3'-end of tRNA through the peptidyl transferase centre and its inhibition by antibiotics

    DEFF Research Database (Denmark)

    Kirillov, Stanislav; Porse, Bo Torben; Vester, Birthe;

    1997-01-01

    Determining how antibiotics inhibit ribosomal activity requires a detailed understanding of the interactions and relative movement of tRNA, mRNA and the ribosome. Recent models for the formation of hybrid tRNA binding sites during the elongation cycle have provided a basis for re-evaluating earlier......RNA-ribosome binding. Nevertheless, these relatively weak interactions determine the unidirectional movement of tRNAs through the ribosome and, moreover, they appear to be particularly susceptible to perturbation by antibiotics. Here we summarise current ideas relating particularly to the movement of the 3'-ends of t......RNA through the ribosome and consider possible inhibitory mechanisms of the peptidyl transferase antibiotics....

  18. Genetic polymorphism of human glutathione S-transferase A1 gene in mainland Chinese and its association with phenotype

    Institute of Scientific and Technical Information of China (English)

    JiePING; HuiWANG

    2005-01-01

    AIM Human glutathione S-transferase A1 (GSTA1) is an important phase Ⅱ metabolizing enzyme involved in the metabolism of many therapeutic drugs and is responsible for the metabolic detoxification of numerous promutagens and procarcinogens. The genetic polymorphism of GSTA1 has important implications for drug efficacy and cancer susceptibility. In this study, we determined the distribution of GSTA1 genetic polymorphism in Mainland Chinese. And we also investigated whether there exists the potential phenotype alterations caused by the genetic polymorphism in human. METHODS Genomic DNA was ex-tracted from peripheral blood of 140 Chinese people and 16 liver tissues obtained from non-liverish patients who underwent partial hepatectomy. And then the genotypes of human GSTA1 gene were analyzed by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP).

  19. Mimicking Insect Communication: Release and Detection of Pheromone, Biosynthesized by an Alcohol Acetyl Transferase Immobilized in a Microreactor

    Science.gov (United States)

    Muñoz, Lourdes; Dimov, Nikolay; Carot-Sans, Gerard; Bula, Wojciech P.; Guerrero, Angel; Gardeniers, Han J. G. E.

    2012-01-01

    Infochemical production, release and detection of (Z,E)-9,11-tetradecadienyl acetate, the major component of the pheromone of the moth Spodoptera littoralis, is achieved in a novel microfluidic system designed to mimic the final step of the pheromone biosynthesis by immobilized recombinant alcohol acetyl transferase. The microfluidic system is part of an “artificial gland”, i.e., a chemoemitter that comprises a microreactor connected to a microevaporator and is able to produce and release a pre-defined amount of the major component of the pheromone from the corresponding (Z,E)-9,11-tetradecadienol. Performance of the entire chemoemitter has been assessed in electrophysiological and behavioral experiments. Electroantennographic depolarizations of the pheromone produced by the chemoemitter were ca. 40% relative to that evoked by the synthetic pheromone. In a wind tunnel, the pheromone released from the evaporator elicited on males a similar attraction behavior as 3 virgin females in most of the parameters considered. PMID:23155372

  20. Mimicking insect communication: release and detection of pheromone, biosynthesized by an alcohol acetyl transferase immobilized in a microreactor.

    Directory of Open Access Journals (Sweden)

    Lourdes Muñoz

    Full Text Available Infochemical production, release and detection of (Z,E-9,11-tetradecadienyl acetate, the major component of the pheromone of the moth Spodoptera littoralis, is achieved in a novel microfluidic system designed to mimic the final step of the pheromone biosynthesis by immobilized recombinant alcohol acetyl transferase. The microfluidic system is part of an "artificial gland", i.e., a chemoemitter that comprises a microreactor connected to a microevaporator and is able to produce and release a pre-defined amount of the major component of the pheromone from the corresponding (Z,E-9,11-tetradecadienol. Performance of the entire chemoemitter has been assessed in electrophysiological and behavioral experiments. Electroantennographic depolarizations of the pheromone produced by the chemoemitter were ca. 40% relative to that evoked by the synthetic pheromone. In a wind tunnel, the pheromone released from the evaporator elicited on males a similar attraction behavior as 3 virgin females in most of the parameters considered.

  1. Glutathione S-transferase (GST) genes in the red flour beetle, Tribolium castaneum, and comparative analysis with five additional insects.

    Science.gov (United States)

    Shi, Houxia; Pei, Lianghong; Gu, Shasha; Zhu, Shicheng; Wang, Yanyun; Zhang, Yi; Li, Bin

    2012-11-01

    Glutathione S-transferases are important detoxification enzymes involved in insecticide resistance. Sequencing the Tribolium castaneum genome provides an opportunity to investigate the structure, function, and evolution of GSTs on a genome-wide scale. Thirty-six putative cytosolic GSTs and 5 microsomal GSTs have been identified in T. castaneum. Furthermore, 40, 35, 13, 23, and 32 GSTs have been discovered the other insects, Drosophila, Anopheles, Apis, Bombyx, and Acyrthosiphon, respectively. Phylogenetic analyses reveal that insect-specific GSTs, Epsilon and Delta, are the largest species-specific expanded GSTs. In T. castaneum, most GSTs are tandemly arranged in three chromosomes. Particularly, Epsilon GSTs have an inverted long-fragment duplication in the genome. Other four widely distributed classes are highly conserved in all species. Given that GSTs specially expanded in Tribolium castaneum, these genes might help to resist poisonous chemical environments and produce resistance to kinds of different insecticides.

  2. Glutathione S-transferase M1 and T1 genotypes and endometriosis risk: a case-controlled study

    Institute of Scientific and Technical Information of China (English)

    林俊; 张信美; 钱羽力; 叶英辉; 石一复; 徐开红; 徐键云

    2003-01-01

    Objective To investigate the correlation between glutathione S-transferase (GST) M1 and T1 genotypes and endometriosis risk (EM). Methods Polymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in genomic DNA isolated from the blood samples of 68 Han Chinese women with endometriosis and 28 without endometriosis. Results The frequencies of GSTM1 and GSTT1 null genotypes in women with endometriosis were 0.721 (49/68) and 0.779 (53/68), respectively, and in women without endometriosis were 0.429 (12/28) and 0.321 (9/28), respectively. There was a significant difference with regard to the frequencies of GSTM1 and GSTT1 null genotypes between the women with and without endometriosis (P0.05). Conclusion GSTM1 and GSTT1 null genotypes may be risk factors for the development of endometriosis.

  3. Micro-plasticity of genomes as illustrated by the evolution of glutathione transferases in 12 Drosophila species.

    Directory of Open Access Journals (Sweden)

    Chonticha Saisawang

    Full Text Available Glutathione transferases (GST are an ancient superfamily comprising a large number of paralogous proteins in a single organism. This multiplicity of GSTs has allowed the copies to diverge for neofunctionalization with proposed roles ranging from detoxication and oxidative stress response to involvement in signal transduction cascades. We performed a comparative genomic analysis using FlyBase annotations and Drosophila melanogaster GST sequences as templates to further annotate the GST orthologs in the 12 Drosophila sequenced genomes. We found that GST genes in the Drosophila subgenera have undergone repeated local duplications followed by transposition, inversion, and micro-rearrangements of these copies. The colinearity and orientations of the orthologous GST genes appear to be unique in many of the species which suggests that genomic rearrangement events have occurred multiple times during speciation. The high micro-plasticity of the genomes appears to have a functional contribution utilized for evolution of this gene family.

  4. Novel functional association of rat testicular membrane-associated cytosolic glutathione S transferases and cyclooxygenase in vitro

    Institute of Scientific and Technical Information of China (English)

    S. Neeraja; B. Ramakrishna; A. S. Sreenath; G. V. Reddy; P. R. K. Reddy; P. Reddanna

    2005-01-01

    Aim: To analyze the role of cytosolic glutathione S-transferases (cGSTs) and membrane-associated cytosolic GSTs (macGSTs) in prostaglandin biosynthesis and to evaluate the possible interaction between glutathione S-transferases (GSTs) and cyclooxygenase (COX) in vitro. Methods: SDS-PAGE analysis was undertaken for characterization of GSTs, thin layer chromatography (TLC) to monitor the effect of GSTs on prostaglandin biosynthesis from arachidonic acid (AA) and spectrophotometric assays were done for measuring activity levels of COX and GSTs. Results:SDS-PAGE analysis indicates that macGSTs have molecular weights in the range of 25-28 kDa. In a coupled assay involving GSTs, arachidonic acid and cyclooxygenase-1, rat testicular macGSTs produced prostaglandin E2 and F2α,while the cGSTs caused the generation of prostaglandin D2, E2 and F2α. In vitro interaction studies on GSTs and COX at the protein level have shown dose-dependent inhibition of COX activity by macGSTs and vice versa. This effect,however, is not seen with cGSTs. The inhibitory effect of COX on macGST activity was relieved with increasing concentrations of reduced glutathione (GSH) but not with 1-chloro 2,4-dinitrobenzene (CDNB). The inhibition of COX by macGSTs, on the other hand, was potentiated by glutathione. Conclusion: We isolated and purified macGSTs and cGSTs from rat testis and analyzed their involvement in prostaglandin biosynthesis. These studies reveal a reversible functional interaction between macGSTs and COX in vitro, with possible interactions between them at the GSH binding site of macGSTs.

  5. Functional characterization of UDP-glucose:undecaprenyl-phosphate glucose-1-phosphate transferases of Escherichia coli and Caulobacter crescentus.

    Science.gov (United States)

    Patel, Kinnari B; Toh, Evelyn; Fernandez, Ximena B; Hanuszkiewicz, Anna; Hardy, Gail G; Brun, Yves V; Bernards, Mark A; Valvano, Miguel A

    2012-05-01

    Escherichia coli K-12 WcaJ and the Caulobacter crescentus HfsE, PssY, and PssZ enzymes are predicted to initiate the synthesis of colanic acid (CA) capsule and holdfast polysaccharide, respectively. These proteins belong to a prokaryotic family of membrane enzymes that catalyze the formation of a phosphoanhydride bond joining a hexose-1-phosphate with undecaprenyl phosphate (Und-P). In this study, in vivo complementation assays of an E. coli K-12 wcaJ mutant demonstrated that WcaJ and PssY can complement CA synthesis. Furthermore, WcaJ can restore holdfast production in C. crescentus. In vitro transferase assays demonstrated that both WcaJ and PssY utilize UDP-glucose but not UDP-galactose. However, in a strain of Salmonella enterica serovar Typhimurium deficient in the WbaP O antigen initiating galactosyltransferase, complementation with WcaJ or PssY resulted in O-antigen production. Gas chromatography-mass spectrometry (GC-MS) analysis of the lipopolysaccharide (LPS) revealed the attachment of both CA and O-antigen molecules to lipid A-core oligosaccharide (OS). Therefore, while UDP-glucose is the preferred substrate of WcaJ and PssY, these enzymes can also utilize UDP-galactose. This unexpected feature of WcaJ and PssY may help to map specific residues responsible for the nucleotide diphosphate specificity of these or similar enzymes. Also, the reconstitution of O-antigen synthesis in Salmonella, CA capsule synthesis in E. coli, and holdfast synthesis provide biological assays of high sensitivity to examine the sugar-1-phosphate transferase specificity of heterologous proteins.

  6. Inductoin of Radioresistance by Overexpression of Glutathione S-Transferase K1 (hGSTK1) in MCF-7 Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Chul [Kyungpook National University College of Medicine, Taegu (Korea, Republic of); Shin, Sei One [Yeungnam University College of Medicine, Taegu (Korea, Republic of)

    2001-12-15

    Purpose : This study was conducted to assess the effects of x-irradiation on the expression of the novel glutathione S-transferase K1 gene. Materials and methods : Human glutathione S-transferase K1 (hGSTK1) DNA was purified and ligated to a pcDNA3.1/Myc-His(+) vector for the overexpression of hGSTK1 gene. MCF-7 cells were transfected with or without the recombinant hGSTK1 gene, and irradiated with 6 MV x-ray. After incubation of 14 days, cell survival was measured and compared. The expression of hGSTK1 and the effect of x- irradiation on hGSTK1 expression were also estimated in MCF-7 cells transfected with or without the hGSTK1 gene by RT-PCR. Results : Following 2 to 12 Gy of x-irradiation, the cell survivals were higher in the MCF-7 cells transfected with the hGSTK1 gene than in those without transfection. Despite the higher cell survival in the hGSTK1-transfected cells, RT-PCR for hGSTK1 mRNA revealed no significant differences according to radiation dose, fractionation, and time after irradiation. Conclusion : The MCF-7 cells transfected with the hGSTK1 gene showed higher cell survival than those without transfection of the gene. The hGSTK1 gene might be associated with the radiosensitivity of MCF-7 cell line and further analysis should be needed.

  7. Synergistic and independent actions of multiple terminal nucleotidyl transferases in the 3' tailing of small RNAs in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wang

    2015-04-01

    Full Text Available All types of small RNAs in plants, piwi-interacting RNAs (piRNAs in animals and a subset of siRNAs in Drosophila and C. elegans are subject to HEN1 mediated 3' terminal 2'-O-methylation. This modification plays a pivotal role in protecting small RNAs from 3' uridylation, trimming and degradation. In Arabidopsis, HESO1 is a major enzyme that uridylates small RNAs to trigger their degradation. However, U-tail is still present in null hen1 heso1 mutants, suggesting the existence of (an enzymatic activities redundant with HESO1. Here, we report that UTP: RNA uridylyltransferase (URT1 is a functional paralog of HESO1. URT1 interacts with AGO1 and plays a predominant role in miRNA uridylation when HESO1 is absent. Uridylation of miRNA is globally abolished in a hen1 heso1 urt1 triple mutant, accompanied by an extensive increase of 3'-to-5' trimming. In contrast, disruption of URT1 appears not to affect the heterochromatic siRNA uridylation. This indicates the involvement of additional nucleotidyl transferases in the siRNA pathway. Analysis of miRNA tailings in the hen1 heso1 urt1 triple mutant also reveals the existence of previously unknown enzymatic activities that can add non-uridine nucleotides. Importantly, we show HESO1 may also act redundantly with URT1 in miRNA uridylation when HEN1 is fully competent. Taken together, our data not only reveal a synergistic action of HESO1 and URT1 in the 3' uridylation of miRNAs, but also independent activities of multiple terminal nucleotidyl transferases in the 3' tailing of small RNAs and an antagonistic relationship between uridylation and trimming. Our results may provide further insight into the mechanisms of small RNA 3' end modification and stability control.

  8. Differential substrate specificity and kinetic behavior of Escherichia coli YfdW and Oxalobacter formigenes formyl coenzyme A transferase.

    Science.gov (United States)

    Toyota, Cory G; Berthold, Catrine L; Gruez, Arnaud; Jónsson, Stefán; Lindqvist, Ylva; Cambillau, Christian; Richards, Nigel G J

    2008-04-01

    The yfdXWUVE operon appears to encode proteins that enhance the ability of Escherichia coli MG1655 to survive under acidic conditions. Although the molecular mechanisms underlying this phenotypic behavior remain to be elucidated, findings from structural genomic studies have shown that the structure of YfdW, the protein encoded by the yfdW gene, is homologous to that of the enzyme that mediates oxalate catabolism in the obligate anaerobe Oxalobacter formigenes, O. formigenes formyl coenzyme A transferase (FRC). We now report the first detailed examination of the steady-state kinetic behavior and substrate specificity of recombinant, wild-type YfdW. Our studies confirm that YfdW is a formyl coenzyme A (formyl-CoA) transferase, and YfdW appears to be more stringent than the corresponding enzyme (FRC) in Oxalobacter in employing formyl-CoA and oxalate as substrates. We also report the effects of replacing Trp-48 in the FRC active site with the glutamine residue that occupies an equivalent position in the E. coli protein. The results of these experiments show that Trp-48 precludes oxalate binding to a site that mediates substrate inhibition for YfdW. In addition, the replacement of Trp-48 by Gln-48 yields an FRC variant for which oxalate-dependent substrate inhibition is modified to resemble that seen for YfdW. Our findings illustrate the utility of structural homology in assigning enzyme function and raise the question of whether oxalate catabolism takes place in E. coli upon the up-regulation of the yfdXWUVE operon under acidic conditions. PMID:18245280

  9. Sites of interaction of streptogramin A and B antibiotics in the peptidyl transferase loop of 23 S rRNA and the synergism of their inhibitory mechanisms

    DEFF Research Database (Denmark)

    Porse, B T; Garrett, R A

    1999-01-01

    nucleotides in the peptidyl transferase loop of 23 S rRNA, including the two mutated nucleotides. An rRNA footprinting study, performed both in vivo and in vitro, on the A and B components complexed to Bacillus megaterium ribosomes, indicated that similar drug-induced effects occur on free ribosomes and...

  10. Glutathione S-transferase phenotypes in relation to genetic variation and fruit and vegetable consumption in an endoscopy-based population.

    NARCIS (Netherlands)

    Tijhuis, M.J.; Visker, M.H.P.W.; Aarts, J.; Peters, W.H.M.; Roelofs, H.M.J.; Camp, L.O. den; Rietjens, I.M.C.M.; Boerboom, A.M.A.; Nagengast, F.M.; Kok, F.J.; Kampman, E.

    2007-01-01

    High glutathione S-transferase (GST) activity may contribute to colorectal cancer prevention. Functional polymorphisms are known in the GSTM1, GSTT1, GSTA1 and GSTP1 genes. The influence of these GST polymorphisms and recent fruit and vegetable consumption on GST levels and activity has not been inv

  11. GLUTATHIONE-S-TRANSFERASE ACTIVITY AND ISOENZYME COMPOSITION IN BENIGN OVARIAN-TUMORS, UNTREATED MALIGNANT OVARIAN-TUMORS, AND MALIGNANT OVARIAN-TUMORS AFTER PLATINUM CYCLOPHOSPHAMIDE CHEMOTHERAPY

    NARCIS (Netherlands)

    VANDERZEE, AGJ; VANOMMEN, B; MEIJER, C; HOLLEMA, H; VANBLADEREN, PJ; DEVRIES, EGE

    1992-01-01

    Glutathione S-transferase (GST) isoenzyme composition, isoenzyme quantities and enzymatic activity were investigated in benign (n = 4) ovarian tumours and malignant ovarian tumours, before (n = 20) and after (n = 16) chemotherapy. Enzymatic activity of GST in cytosols was measured by determining 1-c

  12. Cold sensitivity in rice (Oryza sativa L.) is strongly correlated with a naturally occurring I99V mutation in the multifunctional glutathione transferase isoenzyme GSTZ2

    Science.gov (United States)

    GSTZs (zeta class glutathione transferases) belong to a highly conserved subfamily of soluble GSTs found in species ranging from fungi and plants to animals. GSTZ is identical to MAAI (maleylacetoacetate isomerase), which functions in tyrosine catabolism by catalyzing the isomerization of MAA (maley...

  13. INDUCTION OF DNA-PROTEIN CROSSLINKS BY THE METABOLISM OF DICHLOROMETHANE IN V79 CELL LINES TRANSFECTED WITH THE MURINE GLUTATHIONE-S-TRANSFERASE THETA 1 GENE

    Science.gov (United States)

    Dichloromethane (DCM) is considered a probable human carcinogen. Laboratory studies have shown an increased incidence of lung and liver cancer in mice but not in rats or hamsters. Despite the correlation between metabolism of DCM by the glutathione-S-transferase (GST) pathway and...

  14. Conjugation of isoprene monoepoxides with glutathione, catalyzed by α, μ, π and θ-class glutathione S-transferases of rat and man

    NARCIS (Netherlands)

    Bogaards, J.J.P.; Venekamp, J.C.; Salmon, F.G.C.; Bladeren, P.J. van

    1999-01-01

    In the present study, the enzymatic conjugation of the isoprene monoepoxides 3,4 epoxy-3-methyl-1-butene (EPOX-I) and 3,4-epoxy-2-methyl-1-butene (EPOX-II) with glutathione was investigated, using purified glutathione S-transferases (GSTs) of the α, μ, π and θ-class of rat and man. HPLC analysis of

  15. Correlation of Rutin Accumulation with 3-O-Glucosyl Transferase and Phenylalanine Ammonia-lyase Activities During the Ripening of Tomato Fruit

    NARCIS (Netherlands)

    Capanoglu, E.; Beekwilder, J.; Matros, A.; Boyacioglu, D.; Hall, R.D.; Mock, H.P.

    2012-01-01

    In tomato, the predominant flavonoid is quercetin-3-rutinoside (rutin). In this study, we aim to investigate the phenylalanine ammonia-lyase (PAL) and the quercetin-3-O-glucosyl transferase (3-GT) reactions in the formation of rutin during tomato fruit ripening. Tomatoes of the Moneymaker variety at

  16. Succinyl-CoA:acetoacetate transferase deficiency : identification of a new patient with a neonatal onset and review of the literature

    NARCIS (Netherlands)

    Niezen-Koning, K E; Wanders, R J; Ruiter, J P; Ijlst, L; Visser, G; Reitsma-Bierens, W C; Heijmans, Hugo; Reijngoud, D J; Smit, G P

    1997-01-01

    UNLABELLED: We describe the clinical symptoms and biochemical findings of a patient with succinyl-CoA:acetoacetate transferase deficiency who presented in the neonatal period and review the current literature on this subject. Our patient was initially suspected to have distal renal tubular acidosis,

  17. Pleiotropic effects of polymorphism of the gene diacylglycerol-O-transferase 1 (DGAT1) in the mammary gland tissue of dairy cows

    NARCIS (Netherlands)

    Mach Casellas, N.; Blum, Y.; Bannink, A.; Causeur, D.; Houee-Bigot, M.; Lagarrigue, S.; Smits, M.A.

    2012-01-01

    Microarray analysis was used to identify genes whose expression in the mammary gland of Holstein-Friesian dairy cows was affected by the nonconservative Ala to Lys amino acid substitution at position 232 in exon VIII of the diacylglycerol-O-transferase 1 (DGAT1) gene. Mammary gland biopsies of 9 hom

  18. Succinyl-CoA : acetoacetate transferase deficiency: identification of a new patient with a neonatal onset and review of the literature

    NARCIS (Netherlands)

    NiezenKoning, KE; Ijlst, L; Visser, G; ReitsmaBierens, WCC; Heymans, HSA; Reijngoud, DJ; Smit, GPA; Ruiter, Jos P. N.

    1997-01-01

    We describe the clinical symptoms and biochemical findings of a patient with succinyl-CoA:acetoacetate transferase deficiency who presented in the neonatal period and review the current literature on this subject. Our patient was initially suspected to have distal renal tubular acidosis, and subsequ

  19. High-throughput genotyping of copy number variation in glutathione S-transferases M1 and T1 using real-time PCR in 20,687 individuals

    DEFF Research Database (Denmark)

    Norskov, M.S.; Frikke-Schmidt, R.; Loft, S.;

    2009-01-01

    OBJECTIVES: Characteristic for the genes encoding glutathione S-transferase (GST) M1 and GSTT1 is a null allele, suggested to increase susceptibility to chronic diseases. We report an optimized method for the determination of copy number variation (CNV) in GST genes. DESIGN AND METHODS: Real...

  20. Copy number variation in glutathione S-transferases M1 and T1 and ischemic vascular disease: four studies and meta-analyses

    DEFF Research Database (Denmark)

    Nørskov, Marianne S; Frikke-Schmidt, Ruth; Loft, Steffen;

    2011-01-01

    Glutathione S-transferases (GSTs) M1 and T1 detoxify products of oxidative stress and may protect against atherosclerosis and ischemic vascular disease (IVD). We tested the hypothesis that copy number variation (CNV) in GSTM1 and GSTT1 genes, known to be associated with stepwise decreases...

  1. No elevation of glutathione S-transferase-a1-1 by amiodarone loading in intensive care unit patients with atrial fibrillation.

    NARCIS (Netherlands)

    Hilkens, M.; Pickkers, P.; Peters, W.H.M.; Hoeven, J.G. van der

    2009-01-01

    Hepatocellular toxicity is a putative side-effect of amiodarone. The hepatic detoxification enzyme glutathione S-transferase-A1-1 (GSTA1-1) is a sensitive indicator of hepatocellular damage. We investigated the occurrence of subclinical liver injury, as measured by plasma GSTA1-1 in intensive care u

  2. Purification of a glutathione S-transferase and a glutathione conjugate-specific dehydrogenase involved in isoprene metabolism in Rhodococcus sp. strain AD45

    NARCIS (Netherlands)

    Hylckama Vlieg, Johan E.T. van; Kingma, Jaap; Kruizinga, Wim; Janssen, Dick B.

    1999-01-01

    A glutathione S transferase (GST) with activity toward 1,2-eposy-2-methyl-3-butene (isoprene monoxide) and cis-1,2-dichloroepoxyethane was purified from the isoprene-utilizing bacterium Rhodococcus sp. strain AD45, The homodimeric enzyme (two subunits of 27 kDa each) catalyzed the glutathione (GSH)-

  3. Addition of Rice Bran Arabinoxylan to Curcumin Therapy May Be of Benefit to Patients With Early-Stage B-Cell Lymphoid Malignancies (Monoclonal Gammopathy of Undetermined Significance, Smoldering Multiple Myeloma, or Stage 0/1 Chronic Lymphocytic Leukemia): A Preliminary Clinical Study.

    Science.gov (United States)

    Golombick, Terry; Diamond, Terrence H; Manoharan, Arumugam; Ramakrishna, Rajeev

    2016-06-01

    Hypothesis Prior studies on patients with early B-cell lymphoid malignancies suggest that early intervention with curcumin may lead to delay in progressive disease and prolonged survival. These patients are characterized by increased susceptibility to infections. Rice bran arabinoxylan (Ribraxx) has been shown to have immunostimulatory, anti-inflammatory, and proapoptotic effects. We postulated that addition of Ribraxx to curcumin therapy may be of benefit. Study design Monoclonal gammopathy of undetermined significance (MGUS)/smoldering multiple myeloma (SMM) or stage 0/1 chronic lymphocytic leukemia (CLL) patients who had been on oral curcumin therapy for a period of 6 months or more were administered both curcumin (as Curcuforte) and Ribraxx. Methods Ten MGUS/SMM patients and 10 patients with stage 0/1 CLL were administered 6 g of curcumin and 2 g Ribraxx daily. Blood samples were collected at baseline and at 2-month intervals for a period of 6 months, and various markers were monitored. MGUS/SMM patients included full blood count (FBC); paraprotein; free light chains/ratio; C-reactive protein (CRP)and erythrocyte sedimentation rate (ESR); B2 microglobulin and immunological markers. Markers monitored for stage 0/1 CLL were FBC, CRP and ESR, and immunological markers. Results Of 10 MGUS/SMM patients,5 (50%) were neutropenic at baseline, and the Curcuforte/Ribraxx combination therapy showed an increased neutrophil count, varying between 10% and 90% among 8 of the 10 (80%) MGUS/SMM patients. An additional benefit of the combination therapy was the potent effect in reducing the raised ESR in 4 (44%) of the MGUS/SMM patients. Conclusion Addition of Ribraxx to curcumin therapy may be of benefit to patients with early-stage B-cell lymphoid malignancies. PMID:27154182

  4. Chloromycetin resistance of clinically isolated E coli is conversed by using EGS technique to repress the chloromycetin acetyl transferase

    Institute of Scientific and Technical Information of China (English)

    Mei-Ying Gao; Chuan-Rui Xu; Ru Chen; Shou-Gui Liu; Jiang-Nan Feng

    2005-01-01

    AIM: To explore the possibility of repression of chloromycetin (Cm) acyl transferase by using external guided sequence (EGS) in order to converse the clinical Ecoli isolates from Cm- resistant to Cm- sensitive.METHODS: EGS directed against chloromycetin acetyl transferase gene (cat) was cloned to vector pEGFP-C1 which contains the kanamycin (Km) resistance gene.The recombinant plasmid pEGFP-C1+EGScat1+cat2 was constructed and the blank vector without EGS fragment was used as control plasmids. By using the CaCl2 transformation method, the recombinant plasmids were introduced into the clinically isolated Cm resistant but Km sensitive E colistrains. Transformants were screened on LB agar plates containing Km. Extraction of plasmids and PCR were applied to identify the positive clones.The growth curve of EGS transformed bacteria cultured in broth with Cm resistance was determined by using spectrophotometer at A600. Drug sensitivity was tested in solid culture containing Cm by using KB method.RESULTS: Transformation studies were carried out on 16 clinically isolated Cm-resistant (250 μg/mLof Cm) E colistrains by using pEGFP-C1-EGScat1cat2 recombinant plasmid. Transformants were screened on LB-agar plates containing Km after the transformation using EGS.Of the 16 tested strains, 4 strains were transformed successfully. Transformants with EGS plasmid showed growth inhibition when grown in liquid broth culture containing 200 μg/mL of Cm. In drug sensitivity test,these strains were sensitive to Cm on LB-agar plates containing 200 μg/mL of Cm. Extraction of plasmids and PCR amplification showed the existence of EGS plasmids in these four transformed strains. These results indicated that the Cat of the four clinical isolates had been suppressed and the four strains were converted to Cm sensitive ones.CONCLUSION: The EGS directed against Cat is able to inhibit the expression of Cat, and hence convert Cmresistant bacteria to Cm-sensitive ones. Thus, the EGS has the

  5. Association of genetic polymorphism of glutathione S-transferase (GSTM1, GSTT1, GSTP1) with bladder cancer susceptibility.

    Science.gov (United States)

    Safarinejad, Mohammad Reza; Safarinejad, Saba; Shafiei, Nayyer; Safarinejad, Shiva

    2013-10-01

    The glutathione-S-transferases (GSTs) comprise a class of enzymes that detoxify carcinogenic compounds by conjugating glutathione to facilitate their removal. Polymorphisms in GSTM1, GSTT1, and GSTP1 genes have been related to risk for bladder cancer. Studies focusing on GSTs gene variants relationship with the risk of bladder cancer have produced conflicting and inconsistent results. We examine the association between genetic polymorphism of glutathione S-transferase P1, GSTM1, GSTT1 genes and development of bladder transitional cell carcinoma (TCC). The study population consisted of 166 histologically confirmed male bladder TCC cases and 332 healthy male controls. Genotyping was done using the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method and also investigated combined gene interactions. The GSTP1 Val/Val genotype was significantly associated with bladder cancer (OR = 4.32, 95% CI: 2.64-6.34), whereas the association observed for GSTM1 null (OR = 1.32, 95% CI: 0.82-2.62; P = 0.67) and GSTT1 null genotype (OR = 1.18, 95% CI: 0.79-1.67; P = 0.74) did not reach statistical significance. There was a significant multiple interaction between GSTM1, GSTT1, and GSTP1 genotypes in risk of bladder cancer (P for interaction = 0.02). The risk associated with the concurrent presence of GSTM1 positive and GSTP1 Ile/Val or Val/Val (OR = 3.71, 95% CI: 2.34-5.54) and GSTT1 positive and GSTP1 Ile/Val or Val/Val (OR = 2.66, 95% CI: 1.54-4.72) was statistically significant. Patients carrying GSTP1 Val/Val genotype were at increased risk for developing high-grade (OR = 7.68, 95% CI: 4.73-19.25) and muscle invasive (OR = 10.67, 95% CI: 6.34-21.75) bladder cancer. High risk for bladder TCC also was observed with respect to combined GSTT1 null/GSTP1 Ile/Val or Val/Val (OR = 4.76, 95% CI: 2.68-18.72) and GSTM1 null/GSTT1 null/GSTP1 Ile/Val or Val/Val (OR = 6.42, 95% CI: 4.76-14.72) genotype variant. This study suggests that the GSTP1 polymorphism

  6. Comparison of epsilon- and delta-class glutathione S-transferases: the crystal structures of the glutathione S-transferases DmGSTE6 and DmGSTE7 from Drosophila melanogaster.

    Science.gov (United States)

    Scian, Michele; Le Trong, Isolde; Mazari, Aslam M A; Mannervik, Bengt; Atkins, William M; Stenkamp, Ronald E

    2015-10-01

    Cytosolic glutathione transferases (GSTs) comprise a large family of enzymes with canonical structures that diverge functionally and structurally among mammals, invertebrates and plants. Whereas mammalian GSTs have been characterized extensively with regard to their structure and function, invertebrate GSTs remain relatively unstudied. The invertebrate GSTs do, however, represent potentially important drug targets for infectious diseases and agricultural applications. In addition, it is essential to fully understand the structure and function of invertebrate GSTs, which play important roles in basic biological processes. Invertebrates harbor delta- and epsilon-class GSTs, which are not found in other organisms. Drosophila melanogaster GSTs (DmGSTs) are likely to contribute to detoxication or antioxidative stress during development, but they have not been fully characterized. Here, the structures of two epsilon-class GSTs from Drosophila, DmGSTE6 and DmGSTE7, are reported at 2.1 and 1.5 Å resolution, respectively, and are compared with other GSTs to identify structural features that might correlate with their biological functions. The structures of DmGSTE6 and DmGSTE7 are remarkably similar; the structures do not reveal obvious sources of the minor functional differences that have been observed. The main structural difference between the epsilon- and delta-class GSTs is the longer helix (A8) at the C-termini of the epsilon-class enzymes.

  7. Pummelo Protects Doxorubicin-Induced Cardiac Cell Death by Reducing Oxidative Stress, Modifying Glutathione Transferase Expression, and Preventing Cellular Senescence

    Directory of Open Access Journals (Sweden)

    L. Chularojmontri

    2013-01-01

    Full Text Available Citrus flavonoids have been shown to reduce cardiovascular disease (CVD risks prominently due to their antioxidant effects. Here we investigated the protective effect of pummelo (Citrus maxima, CM fruit juice in rat cardiac H9c2 cells against doxorubicin (DOX- induced cytotoxicity. Four antioxidant compositions (ascorbic acid, hesperidin, naringin, and gallic acid were determined by HPLC. CM significantly increased cardiac cell survival from DOX toxicity as evaluated by MTT assay. Reduction of cellular oxidative stress was monitored by the formation of DCF fluorescent product and total glutathione (GSH levels. The changes in glutathione-S-transferase (GST activity and expression were determined by enzyme activity assay and Western blot analysis, respectively. Influence of CM on senescence-associated β-galactosidase activity (SA-β-gal was also determined. The mechanisms of cytoprotection involved reduction of intracellular oxidative stress, maintaining GSH availability, and enhanced GST enzyme activity and expression. DOX-induced cellular senescence was also attenuated by long-term CM treatment. Thus, CM fruit juice can be promoted as functional fruit to protect cells from oxidative cell death, enhance the phase II GSTP enzyme activity, and decrease senescence phenotype population induced by cardiotoxic agent such as DOX.

  8. Potential use of acetylcholinesterase, glutathione-S-transferase and metallothionein for assessment of contaminated sediment in tropical chironomid, Chironomus javanus.

    Science.gov (United States)

    Somparn, A; Iwai, C B; Noller, B

    2015-11-01

    Heavy metals and organophosphorus insecticide is known to act as disruptors for the enzyme system, leading to physiologic disorders. The present study was conducted to investigate the potential use of these enzymes as biomarkers in assessment of contaminated sediments on tropical chironomid species. Acetylcholinesterase (AChE), glutathione-S-transferase (GST) and metallothionein (MT) activity was measured in the fourth-instar chironomid larvae, Chironomus javanus, Kieffer, after either 48-hr or 96-hr exposure to organophosphorus insecticide, chlorpyrifos (0.01- 0.25 mg kg(-1)) or heavy metal cadmium (0.1-25 mg kg(-1)). Exposure to chlorpyrifos (0.01 mg kg(-1)) at 48 and 96 hr significantly of AChE activity (64.2%-85.9%) and induced GST activity (33.9-63.8%) when compared with control (P GST activity (11.7-40%) and MT level (9.0%-70.5%) when compared with control (P impact of enzyme activity on chlorpyrifos and cadmium contamination. Activity of AChE, GST and MT could serve as potential biomarkers for assessment and biomonitoring the effects of insecticide and heavy metal contamination in tropical aquatic ecosystems. PMID:26688973

  9. Antioxidant defense markers modulated by glutathione S-transferase genetic polymorphism: results of lung cancer case-control study.

    Science.gov (United States)

    Reszka, Edyta; Wasowicz, Wojciech; Gromadzinska, Jolanta

    2007-12-01

    Oxidative stress and xenobiotic metabolizing enzymes are suspected to be related to carcinogenesis by different cellular mechanisms. Hence, our study aimed at identifying potential relationships between antioxidant defense parameters measured in blood and glutathione S-transferase (GST) genetic polymorphisms of four GST izoenzymes in lung cancer patients and reference individuals. The case-control study included 404 lung cancer patients and 410 non-cancer subjects as controls, matched by age, gender and place of living (central Poland). In control subjects with GSTM3*A/*A, GSTT1 null, GSTM1 null + GSTT1 null, GSTM3*A/*A + GSTT1 null genotype, glutathione peroxidase activity was significantly higher (P < 0.05) than in controls possessing respective potential protective GST genotypes. Controls with GSTM3*A/*A + GSTP1*B genotype presented significantly higher ceruloplasmin activity (P < 0.05) than GSTM3*B + GSTP1*A/*A carriers. Zinc level was significantly higher (P < 0.05) in controls and cases with GSTP1*B + GSTT1 null genotype and in cases with GSTM1 null + GSTP1*B genotype, when compared with respective potential protective GST genotypes. This case-control study indicates that particular defective GST genotypes may enhance the defense against oxidative stress. The potential relationship between the investigated antioxidative enzymes and microelements, and common functional genetic polymorphism of GST was observed mostly in control subjects. PMID:18850183

  10. Volatile Gas Production by Methyl Halide Transferase: An In Situ Reporter Of Microbial Gene Expression In Soil.

    Science.gov (United States)

    Cheng, Hsiao-Ying; Masiello, Caroline A; Bennett, George N; Silberg, Jonathan J

    2016-08-16

    Traditional visual reporters of gene expression have only very limited use in soils because their outputs are challenging to detect through the soil matrix. This severely restricts our ability to study time-dependent microbial gene expression in one of the Earth's largest, most complex habitats. Here we describe an approach to report on dynamic gene expression within a microbial population in a soil under natural water levels (at and below water holding capacity) via production of methyl halides using a methyl halide transferase. As a proof-of-concept application, we couple the expression of this gas reporter to the conjugative transfer of a bacterial plasmid in a soil matrix and show that gas released from the matrix displays a strong correlation with the number of transconjugant bacteria that formed. Gas reporting of gene expression will make possible dynamic studies of natural and engineered microbes within many hard-to-image environmental matrices (soils, sediments, sludge, and biomass) at sample scales exceeding those used for traditional visual reporting. PMID:27415416

  11. Glutathione S-transferase SlGSTE1 in Spodoptera litura may be associated with feeding adaptation of host plants.

    Science.gov (United States)

    Zou, Xiaopeng; Xu, Zhibin; Zou, Haiwang; Liu, Jisheng; Chen, Shuna; Feng, Qili; Zheng, Sichun

    2016-03-01

    Spodoptera litura is polyphagous pest insect and feeds on plants of more than 90 families. In this study the role of glutathione S-transferase epilson 1 (slgste1) in S. litura in detoxification was examined. This gene was up-regulated in the midgut of S. litura at the transcriptional and protein levels when the insect fed on Brassica juncea or diet containing phytochemicals such as indole-3-carbinol and allyl-isothiocyanate that are metabolic products of sinigrin and glucobrassicin in B. juncea. The SlGSTE1 could catalyze the conjugation of reduced glutathione and indole-3-carbinol and allyl-isothiocyanate, as well as xanthotoxin, which is a furanocoumarin, under in vitro condition. When the expression of Slgste1 in the larvae was suppressed with RNAi, the larval growth and feeding rate were decreased. Furthermore, the up-regulated expression of the SlGSTE1 protein in the midgut of larvae that fed on different host plants was detected by 2-DE and ESI/MS analysis. The feeding adaptation from the most to the least of the larvae for the various host plants was Brassica alboglabra, Brassica linn. Pekinensis, Cucumis sativus, Ipomoea batatas, Arachis hypogaea and Capsicum frutescens. All the results together suggest that Slgste1 is a critical detoxifying enzyme that is induced by phytochmicals in the host plants and, inter alia, may be related to host plant adaptation of S. litura. PMID:26631599

  12. Evaluation of glutathione S-transferase genetic variants affecting type 2 diabetes susceptibility: a meta-analysis.

    Science.gov (United States)

    Tang, Song-Tao; Wang, Chang-Jiang; Tang, Hai-Qin; Zhang, Qiu; Wang, Yuan

    2013-11-10

    Genetic polymorphisms of glutathione S-transferases (GSTs) and type 2 diabetes mellitus (T2DM) risk have been widely studied, however, the results were somewhat conflicting. To evaluate the association of GSTs (GSTM1, GSTT1 and GSTP1) gene polymorphisms with T2DM, a meta-analysis was performed before October, 2012. ORs were pooled according to random-effects model. There were a total of 1354/1666 (n=9) cases/controls (studies) for GSTM1, 1271/1470 (n=8) for GSTT1, and 1205/1250 (n=7) for GSTM1. There were significant associations between GSTM1 polymorphism, GSTT1 polymorphism and T2DM in the contrast of present genotype vs. null genotype, with pooled OR=1.99 (95%CI=1.46-2.71) and OR=1.61 (95%CI=1.19-2.17), respectively. Yet no significant association of GSTP1 polymorphism and T2DM was showed. When stratified by ethnicity, the significant associations were also existed in Asians for GSTM1 and GSTT1, but not GSTP1. No publication bias but some extent of heterogeneity was observed. Finally, the accumulated evidence proved the obvious associations of GSTM1 and GSTT1 polymorphisms with an increased risk of T2DM.

  13. STUDY OF THE DELETION MUTATION OF GLUTATHIONE S TRANSFERASE M1 GENE AND ITS ROLE IN SUSCEPTIBILITY TO HEPATOCELLULAR CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objection: To investigate the glutathione S transferase M1 (GSTM1) gene inherent deletion and its relation to prevalence of hepatocellular carcinoma (HCC) in Guangxi, China. Methods: The GSTM1 gene polymorphism of 120 HCC patients and 100 healthy subjects both from the same high aflatoxin B1 (AFB1) contaminated area were detected using PCR technique with special primers. Another 40 patients from AFB1 low risk area were also tested. Results: In HCC high risk area, it was found that the frequencies of GSTM1 null genotype in HCC patients and healthy subjects were 59% and 51% respectively, with no significant difference. However, the frequency of GSTM1-null genotype in control group from AFB1 low risk area was lower than those from high risk area (P<0.01). Conclusion: Populations in this HCC endemic region show a higher rate of GSTM1-null genotype, which may be partially responsible for the susceptibility to AFB1 induced HCC. But the detoxification effect of GSTM1 alone is not sufficient to resist the genetic toxicity of AFB1, especially in those people who expose to excess AFB1. The GSTM1 gene deletion would not be suitable as an independent predictor of susceptibility to HCC.

  14. Different effects of nine clausenamide ennatiomers on liver glutathione biosynthesis and glutathione S-transferase activity in mice

    Institute of Scientific and Technical Information of China (English)

    Yu-qun WU; Li-de LIU; Hua-ling WEI; Geng-tao LIU

    2006-01-01

    Aim: To study the effects of nine synthetic clausenamide with different stereo structures on liver glutathione (GSH) biosynthesis and glutathione S-transferase (GST) activity in mice. Methods: The nine test compounds were racemic mixtures and their ennatiomers of clausenamide, neoclausenamide and epineoclausenamide. Mice were administered clausenamide 250 mg/kg once daily for 3 consecutive days, ig, and were killed 24 h after the last dosing. The mouse liver cytosol GSH and GST were determined with related biochemical methods. Results: Nine clausenamides exhibited different effects on liver GSH and GST. Of nine clausenamides, only (+) and (±)clausenamide markedly increased liver cytosol GSH content. The mechanism of increasing liver GSH content of (+)clausenamide is mainly due to stimulating the key limiting enzyme γ-glutamylcysteine synthetase (γ-GCS) activity for GSH biosynthesis. The other test clausenamides had no such effect on liver GSH. All of the nine clausenamides induced a significant increase of GST activity. Conclusion: The effects of clausenamide ennatiomers on liver GST and GSH varied with the alterations of their spatial structures. (+)Clausenamide stimulated liver GSH biosynthesis through enhancingγ-GCS activity.

  15. Aberrant methylation of Glutathione S-transferase P1 and E-cadherin in invasive ductal breast carcinoma and fibroadenoma

    Institute of Scientific and Technical Information of China (English)

    Wings Tjing Yung Loo; Mary Ngan Bing Cheung; Louis Wing Cheong Chow

    2010-01-01

    Objective To investigate the hypermethylation status of glutathione transferase P1(GSTP1) and E cadherin (ECAD), TSGs (tumor suppressor genes) in our breast cancer samples and explore their correlation with clinicopathological features of corresponding cancer patients. Methods One hundred and thirty six IDC (invasive ductal carcinoma) patients were recruited for analysis and 16 fibroadenoma patients acted as control. DNA extraction and methylation specific PCR (MSP) were subsequently performed preceded by pathological examination. Results The percentage of hypermethylated GSTP1 in carcinoma and fibroadenoma groups was 34.92% and 15.79% respectively and the percentage of hypermethylated ECAD in carcinomas and fibroadenomas was 18.00% and 0.00% respectively. Carcinoma had the highest percentage of c erbB2 overexpression being 54.55% among the clinicopathological parameters. Conclusion Hypermethylation patterns are frequent in IDC and seem to relate to c erbB2 overexpression, and such epigenetic change should not be neglected in fibroadenoma. Tumor methylation status in cancer patients can be determined at early stage and it may be a reference for better treatment planning.

  16. Glutathione S-Transferase P1 (GSTP1 gene polymorphism increases age-related susceptibility to hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Kuo Wu-Hsien

    2010-03-01

    Full Text Available Abstract Background Hepatocellular carcinoma (HCC is one of the most frequent malignant neoplasms in the world. Genetic polymorphism has been reported to be a factor increasing the risk of HCC. Phase II enzymes such as glutathione s-transferases (GSTP1, GSTA1 play important roles in protecting cells against damage induced by carcinogens. The aim of this study was to estimate the relationship of the GSTP1 and GSTA1 gene polymorphisms to HCC risk and clinico-pathological status. Methods Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP was used to measure GSTP1 (A→G and GSTA1 (C→T gene polymorphisms in 386 healthy controls and 177 patients with HCC. Results Neither gene polymorphism was associated with the clinico-pathological status of HCC and serum expression of liver-related clinico-pathological markers. No association between the GSTA1 gene polymorphism and HCC susceptibility was found. However, in the younger group, aged ≤ 57 years, individuals with AG or GG alleles of GSTP1 had a 2.18-fold (95%CI = 1.09-4.36; p = 0.02 and 5.64-fold (95%CI = 1.02-31.18; p = 0.04 risk, respectively, of developing HCC compared to individuals with AA alleles, after adjusting for other confounders. Conclusion AG and GG alleles of GSTP1 gene polymorphisms may be considered as factors increasing the susceptibility to and risk of HCC in Taiwanese aged ≤ 57 years.

  17. Metabolism of cisplatin in the organs of Rattus norvegicus: role of Glutathione S-transferase P1.

    Science.gov (United States)

    Nagar, Ritika; Khan, Amir Riyaz; Poonia, Anuj; Mishra, Pankaj Kishor; Singh, Simendra

    2015-03-01

    Glutathione S-transferases (GSTs) play an important role in the biotransformation of endogenous compounds and xenobiotics as well as in the metabolic inactivation of pharmacologically active substances, including anticancer drugs. Using cisplatin as the prototype drug, we investigated if any correlation exists between GSH levels, GSTs/GSTP1 activity and the fate of cisplatin in different organs of Rattus norvegicus. GSH-cisplatin complex was prepared, purified by anion-exchange chromatography and subjected to mass spectroscopic analysis which confirmed the structure to be diglutathione-monoplatinum (diglutathionylplatinum). Purified diglutathionylplatinum was used to quantify metabolite formed in different tissue homogenates. Specific GSTP1 activity was found to be highest in kidneys, which correlated positively with the levels of metabolite formed in renal tissues. Altogether, our results showed that cisplatin metabolism in different organs of rats correlated positively with specific GSTP1 activities and this enzyme may be a critical determinant of extent of cellular uptake or retention of cisplatin in renal and liver tissues.

  18. Expression of Presenilin-2 and Glutathione S Transferase π and Their Clinical Significance in Breast Infiltrating Ductal Carcinoma

    Institute of Scientific and Technical Information of China (English)

    FANWei; WUXiaoting; ZHOUYejiang; ZHOUTong; HUANGXiong

    2005-01-01

    Objective: To investigate the expressions of presenilin-2 (PS2) and glutathione S transferase π (GSTπ) and their roles in prognosis and therapy of breast infiltrating ductal carcinoma. Methods:The paraffin-embedded specimens of 210 patients with breast infiltrating ductal carcinoma were examined by using LSAB immunohistochemistry for the expression of PS2 and GSTπ. Results: The expression rate of PS2 and GSTπ was 49.5% (104/210) and 48.1% (101/210) respectively. The 5-year and 10-year postoperative survival rates in 4 groups, from high to low, were group 1 (PS2 positive expression/GSTπ negative expression), group 2 (PS2 positive expression/GSTπ positive expression), group 3 (PS2 negative expression/GSTπ negative expression) and group 4 (PS2 negative expression/GSTπ positive expression) in turn. Conclusion: The prognosis of the group 1 was the best, followed by the group 2, group 3 and group 4 in turn. These results suggested that the reasonable use of endocrinotherapy and chemotherapy for patients with breast infiltrating ductal carcinoma is necessary.

  19. Conformational change of glutathione-S-transferase by its co-expression with prion domain of yeast Ure2p

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The Ure2 protein from Saccharomyces cerevisisae has a changeable structure similar to that ofrnammalian prion protein. Its N-terminal is the prion domain (PrD) consisting of 65 amino acids which plays a critical role in yeast prion development. In this study, PrD gene was recombinated with glutathione-S-transferase(GST) gene, and a soluble GST-PrD(sGST-PrD) fusion protein was expressed in E. coli. sGST-PrD could spontaneously polymerize into amyloid fibrils in vitro, displaying typical β-sheet-type structure; it had increased resistance to proteinase K and exhibited amvloid-like optical properties. Moreover, the aggregated GST-PrD(aGST-PrD) could induce sGST-PrD to aggregate into fibrils. These results indicate that PrD could change the conformation of GST moiety in a recombinant protein with PrD to form a prion-like chimeric protein, which proves that PrD has the ability to mediate a prion-like conversion of other proteins fused with it.

  20. Genetic polymorphism of glutathione S-transferase T1 gene and susceptibility to idiopathic azoospermia or oligospermia in northwestern China

    Institute of Scientific and Technical Information of China (English)

    Qi-Fei Wu; Jun-Ping Xing; Kai-Fa Tang; Wei Xue; Min Liu; Jian-Hua Sun; Xin-Yang Wang; Xiao-Juan Jin

    2008-01-01

    Aim: To investigate the association of glutathione S-transferase T1 (GSTT1) gene polymorphism in patients with idiopathic azoospermia or oligospermia in the northwestern China population. Methods: In the case-control study, GSTT1 genotypes were identified by multiplex polymerase chain reaction (PCR) with peripheral blood DNA samples from 78 patients with idiopathic azoospermia, 103 patients with idiopathic oligospermia and 156 age-matched controls with normal sperm concentration and motility, according to the criteria adapted from World Health Organization guidelines. All of the patients and controls were from northwestern China. Results: There is a significant association between GSTT1 null genotype with idiopathic azoospermia risk (odds ratio [OR]: 2.36, 95% confidence interval [CI]:1.33-4.20, P = 0.003) or idiopathic oligospermia risk (OR: 2.00, 95% CI: 1.17-3.27, P = 0.010). Conclusion:GSTT1 null genotype is a predisposing risk factor for sporadic idiopathic azoospermia or oligospermia in north-western China.

  1. Characterization of glutathione S-transferases from Sus scrofa, Cydia pomonella and Triticum aestivum: their responses to cantharidin.

    Science.gov (United States)

    Yang, Xue-Qing; Zhang, Ya-Lin

    2015-02-01

    Glutathione S-transferases (GSTs) play a key role in detoxification of xenobiotics in organisms. However, their other functions, especially response to the natural toxin cantharidin produced by beetles in the Meloidae and Oedemeridae families, are less known. We obtained GST cDNAs from three sources: Cydia pomonella (CpGSTd1), Sus scrofa (SsGSTα1), and Triticum aestivum (TaGSTf3). The predicted molecular mass is 24.19, 25.28 and 24.49 kDa, respectively. These proteins contain typical N-terminal and C-terminal domains. Recombinant GSTs were heterologously expressed in Escherichia coli as soluble fusion proteins. Their optimal activities are exhibited at pH 7.0-7.5 at 30 °C. Activity of CpGSTd1 is strongly inhibited by cantharidin and cantharidic acid, but is only slightly suppressed by the demethylated analog of cantharidin and cantharidic acid. Enzymatic assays revealed that cantharidin has no effect on SsGSTα1 activity, while it significantly stimulates TaGSTf3 activity, with an EC50 value of 0.3852 mM. Activities of these proteins are potently inhibited by the known GST competitive inhibitor: S-hexylglutathione (GTX). Our results suggest that these GSTs from different sources share similar structural and biochemical characteristics. Our results also suggest that CpGSTd1 might act as a binding protein with cantharidin and its analogs.

  2. Expression of c-erbB-2 and glutathione S-transferase-pi in hepatocellular carcinoma and its adjacent tissue

    Institute of Scientific and Technical Information of China (English)

    Zhao-Shan Niu; Mei Wang

    2005-01-01

    AIM: To investigate the possible role of c-erbB-2 and glutathione S-transferase (GST-Pi) in primary hepatocellular carcinogenesis and the relationship between liver hyperplastic nodule (LHN), liver cirrhosis (LC), and hepatocellular carcinoma (HCC).METHODS: The expression of c-erbB-2 and GST-Pi was detected immunohistochemically in 41 tissue specimens of HCC and 77 specimens of its adjacent tissue.RESULTS: The positive expression of c-erbB-2 in LHN (28.6%) was significantly higher than that in LC (0%)(P = 0.032<0.05), but no significant difference was seen between HCC and LHN or LC (P>0.05,x2 = 0.002, 3.447).The positive expression of GST-Pi in HCC (89.6%) or LHN (71.1%) was significantly higher than that in LC (22.9%, P<0.001, x2= 49.91, 16.96). There was a significant difference between HCC and LHN (P<0.05,x2= 6.353).CONCLUSION: The c-erbB-2 expression is an early event in the pathogenesis of HCC. GST-Pi may be a marker enzyme for immunohistochemical detection of human HCC and its preneoplastic lesions. LHN seems to be a preneoplastic lesion related to hepatocarcinogenesis.

  3. Polymorphism of glutathione S-transferase mu 1 and theta 1 genes and hepatocellular carcinoma in southern Guangxi, China

    Institute of Scientific and Technical Information of China (English)

    Zhuo-Lin Deng; Yi-Ping Wei; Yun Ma

    2005-01-01

    AIM: Glutathione S-transferase mu 1 (GSTM1) and theta 1(GSTT1) genes are involved in the metabolism of a wide range of carcinogens, but deletions of the genes are commonly found in the population. The present study was undertaken to evaluate the association between GSTM1 and GSTT1 gene polymorphisms and hepatocellular carcinoma (HCC) risk.METHODS: The genetic polymorphisms were studied at an aflatoxin highly contaminated region in Guangxi, China.Polymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in blood samples. The case group was composed of 181 patients of HCC identified by the pathologists and the control group was composed of 360 adults without any tumor.RFSULTS: The frequencies of GSTM1 and GSTT1 null genotypes in the control were 47.8% and 42.7%, while those in the HCC group were 64.6% and 59.7%, respectively. The differences between HCC group and control group were very significant (P<0.01). GSTM1 and GSTT1 combined null genotypes in HCC group and control group were 38.2% and 18.5%respectively, and the difference was significant (P<0.05).CONCLUSION: The GSTM1 and GSTT1 null genotypes are associated with an increased risk of HCC in a special geographic environment. Combination of the two null genotypes in an individual is substantially increased twice the risk of HCC.

  4. PABA/NO lead optimization: Improved targeting of cytotoxicity to glutathione S-transferase P1-overexpressing cancer cells.

    Science.gov (United States)

    Kim, Youseung; Maciag, Anna E; Cao, Zhao; Deschamps, Jeffrey R; Saavedra, Joseph E; Keefer, Larry K; Holland, Ryan J

    2015-08-01

    PABA/NO [O(2)-{2,4-dinitro-5-[4-(N-methylamino)benzoyloxy]phenyl} 1-(N,N-dimethylamino) diazen-1-ium-1,2-diolate] is a nitric oxide (NO)-releasing arylating agent designed to be selectively activated by reaction with glutathione (GSH) on catalysis by glutathione S-transferase P1 (GSTP1), an enzyme frequently overexpressed in cancer cells. PABA/NO has proven active in several cancer models in vitro and in vivo, but its tendency to be metabolized via a variety of pathways, some that generate inactive metabolites and hydrolysis products, limits its potential as a drug. Here we show that a simple replacement of cyano for nitro at the 4 position to give compound 4b ('p-cyano-PABA/NO') has the dual effect of slowing the undesired side reactions while enhancing the proportion of NO release and arylating activity on catalysis by GSTP1. Compound 4b showed increased resistance to hydrolysis and uncatalyzed reaction with GSH, along with a more favorable product distribution in the presence of GSTP1. It also showed significant proapoptotic activity. The data suggest p-cyano-PABA/NO to be a more promising prodrug than PABA/NO, with better selectivity toward cancer cells.

  5. Computational QM/MM Study of the Reaction Mechanism of Human Glutathione S-Transferase A3-3

    Science.gov (United States)

    Calvaresi, Matteo; Stenta, Marco; Altoè, Piero; Bottoni, Andrea; Garavelli, Marco; Spinelli, Domenico

    2007-12-01

    Human Glutathione S-Transferase A3-3(hGSTA3-3) is the most efficient human steroid double-bond isomerase enzyme. It catalyzes the double bond isomerization of Δ5-androstene-3,17-dione (Δ5-AD) and Δ5-pregnene-3,20-dione (Δ5-PD). The isomerization products are the precursors of the steroid hormones testosterone and progesterone. We have carried out a QM/MM study to elucidate some interesting aspects of the enzyme catalytic mechanism. In particular, we have analyzed either a concerted or a stepwise reaction path. Moreover, we have attempted to rationalize the electrostatic effects on the catalytic activity of the residues surrounding the active site. Specifically, we have performed a "finger print" analysis to determine the electrostatic contribution of each aminoacid residue to the global electrostatic term, thus ranking the effect of the various aminoacids in the course of the reaction. In this way, we have highlighted the most important terms affecting the stabilization-destabilization of the enzyme.

  6. Glutathione-S-transferases M1/T1 gene polymorphisms and endometriosis: a meta-analysis in Chinese populations.

    Science.gov (United States)

    Chen, Xin-Ping; Xu, Da-Feng; Xu, Wei-Hua; Yao, Jia; Fu, Sheng-Miao

    2015-01-01

    In view of the controversies surrounding the glutathione-S-transferases (GST) M1/T1-endometriosis association, a meta-analysis of the GSTM1/GSTT1 genetic association studies of endometriosis was performed in Chinese populations. PubMed, Springer Link, OvidSP, and Chinese databases were searched for related studies. A total of nine studies on GSTM1-endometriosis involved 874 cases and 997 controls, and five studies on GSTT1 involved 404 cases and 513 controls were included in this meta-analysis. Overall, the null genotype of GSTM1/GSTT1 was significantly related to endometriosis risk in Chinese populations (GSTM1, OR = 2.21, 95% CI: 1.22-4.01; GSTT1, OR = 2.31, 95% CI: 1.34-3.99). In subgroup analyses stratified by ethnicity and source of controls, the same results were observed in Chinese Han and population-based studies. The sensitivity analysis confirmed the reliability and stability of the meta-analysis. No publication bias was found among studies by Egger's test. In conclusion, our meta-analysis supports that the GSTM1/GSTT1 null genotype might contribute to individual susceptibility to endometriosis in Chinese populations, especially in Chinese Han.

  7. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines.

    Science.gov (United States)

    López-Cruz, Roberto I; Crocker, Daniel E; Gaxiola-Robles, Ramón; Bernal, Jaime A; Real-Valle, Roberto A; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements.

  8. Nicotinamide phosphoribosyl transferase (Nampt is a target of microRNA-26b in colorectal cancer cells.

    Directory of Open Access Journals (Sweden)

    Chenpeng Zhang

    Full Text Available A number of cancers show increased expression of Nicotinamide phosphoribosyl transferase (Nampt. However, the mechanism through which Nampt is upregulated is unclear. In our study, we found that the Nampt-specific chemical inhibitor FK866 significantly inhibited cell survival and reduced nicotinamide adenine dinucleotide (NAD levels in LoVo and SW480 cell lines. Bioinformatics analyses suggested that miR-26b targets Nampt mRNA. We identified Nampt as a new target of miR-26b and demonstrated that miR-26b inhibits Nampt expression at the protein and mRNA levels by binding to the Nampt 3'-UTR. Moreover, we found that miR-26b was down regulated in cancer tissues relative to that in adjacent normal tissues in 18 colorectal cancer patients. A statistically significant inverse correlation between miR-26b and Nampt expression was observed in samples from colorectal cancer patients and in 5 colorectal cell lines (HT-29, SW480, SW1116, LoVo, and HCT116. In addition, over expression of miR-26b strongly inhibited LoVo cell survival and invasion, an effect partially abrogated by the addition of NAD. In conclusion, this study demonstrated that the NAD-salvaging biosynthesis pathway involving Nampt might play a role in colorectal cancer cell survival. MiR-26b may serve as a tumor suppressor by targeting Nampt.

  9. An acetylation site in lectin domain modulates the biological activity of polypeptide GalNAc-transferase-2

    DEFF Research Database (Denmark)

    Zlocowski, Natacha; Lorenz, Virginia; Bennett, Eric Paul;

    2013-01-01

    Abstract Polypeptide GalNAc-transferases (ppGalNAc-Ts) are a family of enzymes that catalyze the initiation of mucin-type O-glycosylation. All ppGalNAc-T family members contain a common (QXW)3 motif which is present in R-type lectin group. Acetylation site K521 is part of the QKW motif of ß......-trefoil in the lectin domain of ppGalNAc-T2. We used a combination of acetylation and site-directed mutagenesis approaches to examine the functional role of K521 in ppGalNAc-T2. Binding assays of non-acetylated and acetylated forms of the mutant ppGalNAc-T2K521Q to various naked and aGalNAc-glycosylated mucin peptides...... indicated that degree of interaction of lectin domain with aGalNAc depends on the peptide sequence of mucin. Studies of inhibitory effect of various carbohydrates on interactions of ppGalNAc-T2 with MUC1aGalNAc indicate that point K521Q mutation enhance the carbohydrate specificity of lectin domain for aGalNAc...

  10. Probing isoform-specific functions of polypeptide GalNAc-transferases using zinc finger nuclease glycoengineered SimpleCells

    DEFF Research Database (Denmark)

    Schjoldager, Katrine Ter-Borch Gram; Vakhrushev, Sergey Y; Kong, Yun;

    2012-01-01

    Our knowledge of the O-glycoproteome [N-acetylgalactosamine (GalNAc) type] is highly limited. The O-glycoproteome is differentially regulated in cells by dynamic expression of a subset of 20 polypeptide GalNAc-transferases (GalNAc-Ts), and methods to identify important functions of individual GalNAc...... to include proteome-wide discovery of unique functions of individual GalNAc-Ts. We used the GalNAc-T2 isoform implicated in dyslipidemia and the human HepG2 liver cell line to demonstrate unique functions of this isoform. We confirm that GalNAc-T2-directed site-specific O-glycosylation inhibits proprotein...... activation of the lipase inhibitor ANGPTL3 in HepG2 cells and further identify eight O-glycoproteins exclusively glycosylated by T2 of which one, ApoC-III, is implicated in dyslipidemia. Our study supports an essential role for GalNAc-T2 in lipid metabolism, provides serum biomarkers for GalNAc-T2 enzyme...

  11. Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation

    Science.gov (United States)

    Lira-Navarrete, Erandi; de Las Rivas, Matilde; Compañón, Ismael; Pallarés, María Carmen; Kong, Yun; Iglesias-Fernández, Javier; Bernardes, Gonçalo J. L.; Peregrina, Jesús M.; Rovira, Carme; Bernadó, Pau; Bruscolini, Pierpaolo; Clausen, Henrik; Lostao, Anabel; Corzana, Francisco; Hurtado-Guerrero, Ramon

    2015-05-01

    Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity and relies on a flexible linker located between the catalytic and the lectin domains. Our results also shed light on how GalNAc-Ts generate dense decoration of proteins with O-glycans.

  12. Transcriptional profiles of glutathione-S-Transferase isoforms, Cyp, and AOE genes in atrazine-exposed zebrafish embryos.

    Science.gov (United States)

    Glisic, Branka; Hrubik, Jelena; Fa, Svetlana; Dopudj, Nela; Kovacevic, Radmila; Andric, Nebojsa

    2016-02-01

    Glutathione-S-transferase (GST) superfamily consists of multiple members involved in xenobiotic metabolism. Expressional pattern of the GST isoforms in adult fish has been used as a biomarker of exposure to environmental chemicals. However, GST transcriptional responses vary across organs, thus requiring a cross-tissue examination of multiple mRNAs for GST profiling in an animal after chemical exposure. Zebrafish embryos express all GST isoforms as adult fish and could therefore represent an alternative model for identification of biomarkers of exposure. To evaluate such a possibility, we studied a set of cytosolic and microsomal GST isoform-specific expression profiles in the zebrafish embryos after exposure to atrazine, a widely used herbicide. Expression of the GST isoforms was compared with that of CYP genes involved in the phase I of xenobiotic metabolism and antioxidant enzyme (AOE) genes. Using quantitative real-time PCR, we showed dynamic changes in the expressional pattern of twenty GST isoforms, cyp1a, cyp3a65, ahr2, and four AOEs in early development of zebrafish. Acute (48 and 72 h) exposure of 24 h-old embryos to atrazine, from environmentally relevant (0.005 mg/L) to high (40 mg/L) concentrations, caused a variety of transient, albeit minor changes (atrazine (5 and 40 mg/L). In summary, an analysis of the response of multiple systems in the zebrafish embryos provided a comprehensive understanding of atrazine toxicity and its potential impact on biological processes.

  13. Terminal deoxynucleotidyl transferase is down-regulated by AP-1-like regulatory elements in human lymphoid cells.

    Science.gov (United States)

    Peralta-Zaragoza, Oscar; Recillas-Targa, Félix; Madrid-Marina, Vicente

    2004-02-01

    Terminal deoxynucleotidyl transferase (TdT) is a template-independent DNA polymerase that catalyses the incorporation of deoxyribonucleotides into the 3'-hydroxyl end of DNA templates and is thought to increase junctional diversity of antigen receptor genes. TdT is expressed only on immature lymphocytes and acute lymphoblastic leukaemia cells and its transcriptional expression is tightly regulated. We had previously found that protein kinase C (PKC) activation down-regulates TdT expression. PKC-activation induces the synthesis of the Fos and Jun proteins, known as the major components of activation protein 1 (AP-1) transcriptional factor implicated in transcriptional control. Here we report the identification of several DNA-protein interactions within the TdT promoter region in non-TdT expressing human cells. Sequence analysis revealed the presence of a putative AP-1-like DNA-binding site, suggesting that AP-1 may play a relevant role in TdT transcriptional regulation. Using a different source of nuclear extracts and the AP-1-TdT motif as a probe we identified several DNA-protein retarded complexes in electrophoretic mobility shift assays. Super-band shifting analysis using an antibody against c-Jun protein confirmed that the main interaction is produced by a nuclear factor that belongs to the AP-1 family transcription factors. Our findings suggest that the TdT gene expression is down-regulated, at least in part, through AP-1-like transcription factors. PMID:15027905

  14. The Putative O-Linked N-Acetylglucosamine Transferase SPINDLY Inhibits Class I TCP Proteolysis to Promote Sensitivity to Cytokinin.

    Science.gov (United States)

    Steiner, Evyatar; Livne, Sivan; Kobinson-Katz, Tammy; Tal, Lior; Pri-Tal, Oded; Mosquna, Assaf; Tarkowská, Danuše; Mueller, Bruno; Tarkowski, Petr; Weiss, David

    2016-06-01

    Arabidopsis (Arabidopsis thaliana) SPINDLY (SPY) is a putative serine and threonine O-linked N-acetylglucosamine transferase (OGT). While SPY has been shown to suppress gibberellin signaling and to promote cytokinin (CK) responses, its catalytic OGT activity was never demonstrated and its effect on protein fate is not known. We previously showed that SPY interacts physically and functionally with TCP14 and TCP15 to promote CK responses. Here, we aimed to identify how SPY regulates TCP14/15 activities and how these TCPs promote CK responses. We show that SPY activity is required for TCP14 stability. Mutation in the putative OGT domain of SPY (spy-3) stimulated TCP14 proteolysis by the 26S proteasome, which was reversed by mutation in CULLIN1 (CUL1), suggesting a role for SKP, CUL1, F-box E3 ubiquitin ligase in TCP14 proteolysis. TCP14 proteolysis in spy-3 suppressed all TCP14 misexpression phenotypes, including the enhanced CK responses. The increased CK activity in TCP14/15-overexpressing flowers resulted from increased sensitivity to the hormone and not from higher CK levels. TCP15 overexpression enhanced the response of the CK-induced synthetic promoter pTCS to CK, suggesting that TCP14/15 affect early steps in CK signaling. We propose that posttranslational modification of TCP14/15 by SPY inhibits their proteolysis and that the accumulated proteins promote the activity of the CK phosphorelay cascade in developing Arabidopsis leaves and flowers. PMID:27208284

  15. Genome-Wide Analysis of the Glutathione S-Transferase Gene Family in Capsella rubella: Identification, Expression, and Biochemical Functions

    Science.gov (United States)

    He, Gang; Guan, Chao-Nan; Chen, Qiang-Xin; Gou, Xiao-Jun; Liu, Wei; Zeng, Qing-Yin; Lan, Ting

    2016-01-01

    Extensive subfunctionalization might explain why so many genes have been maintained after gene duplication, which provides the engine for gene family expansion. However, it is still a particular challenge to trace the evolutionary dynamics and features of functional divergences in a supergene family over the course of evolution. In this study, we identified 49 Glutathione S-transferase (GST) genes from the Capsella rubella, a close relative of Arabidopsis thaliana and a member of the mustard family. Capsella GSTs can be categorized into eight classes, with tau and phi GSTs being the most numerous. The expansion of the two classes mainly occurs through tandem gene duplication, which results in tandem-arrayed gene clusters on chromosomes. By integrating phylogenetic analysis, expression patterns, and biochemical functions of Capsella and Arabidopsis GSTs, functional divergence, both in gene expression and enzymatic properties, were clearly observed in paralogous gene pairs in Capsella (even the most recent duplicates), and orthologous GSTs in Arabidopsis/Capsella. This study provides functional evidence for the expansion and organization of a large gene family in closely related species.

  16. Cloning and sequencing of protein L-isoaspartyl O-methyl transferase of Salmonella Typhimurium isolated from poultry

    Directory of Open Access Journals (Sweden)

    S. K. Dixit

    2014-09-01

    Full Text Available Aim: To clone the Salmonella Typhimurium protein L-isoaspartyl O-methyl transferase (PIMT enzyme and to analyze the sequence with PIMT gene of other pathogenic serovars of Salmonella. Materials and Methods: Salmonella Typhimurium strain E-2375 was procured from the National Salmonella Center, IVRI. The genomic DNA was isolated from Salmonella Typhimurium. Polymerase chain reaction (PCR was carried out to amplify PIMT gene using the designed primers. The PCR product was cloned into pET28c plasmid vector and transformed into Escherichia coli DH5α cells. The plasmid was isolated from E. coli and was sequenced. The sequence was analyzed and submitted in Genbank. Results: The PCR product revealed a distinct amplicon of 627 bp. The clone was confirmed by PCR. Sequencing data revealed 100% homology between PIMT sequences from Salmonella Typhimurium strain E-2375 (used in the current study and PIMT sequences of standard reported strain (Salmonella Typhimurium str. LT2 in NCBI data base. This submitted sequence in Genbank having accession no. KJ575536. Conclusions: PIMT gene of Salmonella is highly conserved in most of the pathogenic Salmonella serovars. The PIMT clone can be used to isolate PIMT protein. This PIMT protein will be helpful to identify isoaspartate containing proteins thus can help in study Salmonella virulence.

  17. Orotate phosphoribosyl transferase MoPyr5 is involved in uridine 5'-phosphate synthesis and pathogenesis of Magnaporthe oryzae.

    Science.gov (United States)

    Qi, Zhongqiang; Liu, Muxing; Dong, Yanhan; Yang, Jie; Zhang, Haifeng; Zheng, Xiaobo; Zhang, Zhengguang

    2016-04-01

    Orotate phosphoribosyl transferase (OPRTase) plays an important role in de novo and salvage pathways of nucleotide synthesis and is widely used as a screening marker in genetic transformation. However, the function of OPRTase in plant pathogens remains unclear. In this study, we characterized an ortholog of Saccharomyces cerevisiae Ura5, the OPRTase MoPyr5, from the rice blast fungus Magnaporthe oryzae. Targeted gene disruption revealed that MoPyr5 is required for mycelial growth, appressorial turgor pressure and penetration into plant tissues, invasive hyphal growth, and pathogenicity. Interestingly, the ∆Mopyr5 mutant is also involved in mycelial surface hydrophobicity. Exogenous uridine 5'-phosphate (UMP) restored vegetative growth and rescued the defect in pathogenicity on detached barley and rice leaf sheath. Collectively, our results show that MoPyr5 is an OPRTase for UMP biosynthesis in M. oryzae and indicate that UTP biosynthesis is closely linked with vegetative growth, cell wall integrity, and pathogenicity of fungus. Our results also suggest that UMP biosynthesis would be a good target for the development of novel fungicides against M. oryzae. PMID:26810198

  18. Some novel features of glutathione transferase from juvenile catfish (Clarias gariepinus exposed to lindane-contaminated water

    Directory of Open Access Journals (Sweden)

    Yetunde Adedolapo Ojopagogo

    2015-03-01

    Full Text Available Catfish are hardy in nature and it is not known whether the presence of efficient detoxication enzymes is partly responsible for this trait. To investigate this, we have assessed induction of glutathione transferase (GST in 10-week-old juvenile catfish (Clarias gariepinus exposed to graded concentrations of lindane, an organochlorine insecticide, and characterised the purified enzyme from groups having the highest and statistically significant induction. Some of the unique properties observed for the purified enzyme are a high Km (1.72±0.21 mM for the electrophilic model substrate, 1-chloro-2,4-dinitrobenzene (CDNB and a very low catalytic rate (Vmax=0.130±0.010 units/mg protein. The kcat/Km being 55.4±0.2 M−1 s−1. The enzyme is present in high concentration in the organism, the main isoform accounts for about 5.6% of the total soluble protein, probably to compensate for the observed kinetic imperfection. Since these properties are generally not known for a detoxication enzyme, we suggest that they may form part of the organism׳s own adaptation to its polluted environment.

  19. The Glutathione-S-Transferase, Cytochrome P450 and Carboxyl/Cholinesterase Gene Superfamilies in Predatory Mite Metaseiulus occidentalis

    Science.gov (United States)

    Hoy, Marjorie A.

    2016-01-01

    Pesticide-resistant populations of the predatory mite Metaseiulus (= Typhlodromus or Galendromus) occidentalis (Arthropoda: Chelicerata: Acari: Phytoseiidae) have been used in the biological control of pest mites such as phytophagous Tetranychus urticae. However, the pesticide resistance mechanisms in M. occidentalis remain largely unknown. In other arthropods, members of the glutathione-S-transferase (GST), cytochrome P450 (CYP) and carboxyl/cholinesterase (CCE) gene superfamilies are involved in the diverse biological pathways such as the metabolism of xenobiotics (e.g. pesticides) in addition to hormonal and chemosensory processes. In the current study, we report the identification and initial characterization of 123 genes in the GST, CYP and CCE superfamilies in the recently sequenced M. occidentalis genome. The gene count represents a reduction of 35% compared to T. urticae. The distribution of genes in the GST and CCE superfamilies in M. occidentalis differs significantly from those of insects and resembles that of T. urticae. Specifically, we report the presence of the Mu class GSTs, and the J’ and J” clade CCEs that, within the Arthropoda, appear unique to Acari. Interestingly, the majority of CCEs in the J’ and J” clades contain a catalytic triad, suggesting that they are catalytically active. They likely represent two Acari-specific CCE clades that may participate in detoxification of xenobiotics. The current study of genes in these superfamilies provides preliminary insights into the potential molecular components that may be involved in pesticide metabolism as well as hormonal/chemosensory processes in the agriculturally important M. occidentalis. PMID:27467523

  20. Effect of Arsenic and Chromium on the Serum Amino-Transferases Activity in Indian Major Carp, Labeo rohita

    Directory of Open Access Journals (Sweden)

    Anjaneyulu Yerramilli

    2007-09-01

    Full Text Available Arsenic and hexavalent chromium toxicity results from their ability to interact with sulfahydryl groups of proteins and enzymes, and to substitute phosphorus in a variety of biochemical reactions. Alanine aminotransferase (ALT; E.C: 2.6.1.2 and Aspartate amino transferase (AST; EC 2.6.1.1 play a crucial role in transamination reactions and can be used as potential biomarkers to indicate hepatotoxicity and cellular damage. While histopathological studies in liver tissue require more time and expertise, simple and reliable biochemical analysis of ALT and AST can be used for a rapid assessment of tissue and cellular damage within 96 h. The main objective of this study was to determine the acute effects of arsenic and hexavalent chromium on the activity of ALT and AST in the Indian major carp, Labeo rohita for 24 h and 96 h. Significant increase in the activity of ALT (P < 0.01 from controls in arsenic exposed fish indicates serious hepatic damage and distress condition to the fish. However, no such significant changes were observed in chromium-exposed fish suggesting that arsenic is more toxic to the fish. These findings indicate that ALT and AST are candidate biomarkers for arsenic-induced hepatotoxicity in Labeo rohita.

  1. Non-enzymatic roles for the URE2 glutathione S-transferase in the response of Saccharomyces cerevisiae to arsenic.

    Science.gov (United States)

    Todorova, Tatina T; Kujumdzieva, Anna V; Vuilleumier, Stéphane

    2010-11-01

    The response of Saccharomyces cerevisiae to arsenic involves a large ensemble of genes, many of which are associated with glutathione-related metabolism. The role of the glutathione S-transferase (GST) product of the URE2 gene involved in resistance of S. cerevisiae to a broad range of heavy metals was investigated. Glutathione peroxidase activity, previously reported for the Ure2p protein, was unaffected in cell-free extracts of an ure2Δ mutant of S. cerevisiae. Glutathione levels in the ure2Δ mutant were lowered about threefold compared to the isogenic wild-type strain but, as in the wild-type strain, increased 2-2.5-fold upon addition of either arsenate (As(V)) or arsenite (As(III)). However, lack of URE2 specifically caused sensitivity to arsenite but not to arsenate. The protective role of URE2 against arsenite depended solely on the GST-encoding 3'-end portion of the gene. The nitrogen source used for growth was suggested to be an important determinant of arsenite toxicity, in keeping with non-enzymatic roles of the URE2 gene product in GATA-type regulation. PMID:20740275

  2. Evaluation of the non-catalytic binding function of Ts26GST a glutathione transferase isoform of Taenia solium.

    Science.gov (United States)

    Plancarte, A; Romero, J R; Nava, G; Reyes, H; Hernández, M

    2014-03-01

    Taenia solium glutathione transferase isoform of 26.5 kDa (Ts26GST) was observed to bind non-catalytically to porphyrins, trans-trans-dienals, bile acids and fatty acids, as assessed by inhibition kinetics, fluorescence spectroscopy and competitive fluorescence assays with 8-anilino-1-naphthalene sulfonate (ANS). The quenching of Ts26GST intrinsic fluorescence allowed for the determination of the dissociation constants (KD) for all ligands. Obtained data indicate that Ts26GST binds to all ligands but with different affinity. Porphyrins and lipid peroxide products inhibited Ts26GST catalytic activity up to 100% in contrast with only 20-30% inhibition observed for bile acids and two saturated fatty acids. Non-competitive type inhibition was observed for all enzyme inhibitor ligands except for trans-trans-2,4-decadienal, which exhibited uncompetitive type inhibition. The dissociation constant value KD = 0.7 μM for the hematin ligand, determined by competitive fluorescence assays with ANS, was in good agreement with its inhibition kinetic value Ki = 0.3 μM and its intrinsic fluorescence quenching KD = 0.7 μM. The remaining ligands did not displace ANS from the enzyme suggesting the existence of different binding sites. In addition to the catalytic activity of Ts26GST the results obtained suggest that the enzyme exhibits a ligandin function with broad specificity towards nonsubstrate ligands.

  3. Glutathione S-Transferase activity and total thiol status in chronic alcohol abusers before and 30 days after alcohol abstinence

    Directory of Open Access Journals (Sweden)

    Manjunatha S Muttigi

    2009-05-01

    Full Text Available Background: Glutathione S Transferase (GST has been involved in detoxification process in the liver and its activity has been shown to be increased in alcohol abusers. In the current work we measured the GST activity, total thiol status, AST, ALT, and direct bilirubin in chronic alcohol abusers before and 30 days after alcohol abstinence and lifestyle modification. Methods: Serum and urine GST activity and total thiol status were determined using spectrophotometric methods and serum transaminases were determined using clinical chemistry analyzer. Results: We found,significant increase in serum and urine GST (p<0.001, AST (p<0.001, ALT (p<0.001, and decrease in total thiol status (p<0.001 in chronic alcohol abusers. GST activity significantly decreased (p<0.001 and total thiol status were improved significantly (p<0.001 30 days after alcohol abstinence and lifestyle modification. Conclusion: This study provides preliminary data to suggest the role of GST as prognostic indicator of alcohol abstinence with possible trend towards an improvement in liver function.

  4. Plasma Hypoxanthine-Guanine Phosphoribosyl Transferase Activity in Bottlenose Dolphins Contributes to Avoiding Accumulation of Non-recyclable Purines

    Science.gov (United States)

    López-Cruz, Roberto I.; Crocker, Daniel E.; Gaxiola-Robles, Ramón; Bernal, Jaime A.; Real-Valle, Roberto A.; Lugo-Lugo, Orlando; Zenteno-Savín, Tania

    2016-01-01

    Marine mammals are exposed to ischemia/reperfusion and hypoxia/reoxygenation during diving. During oxygen deprivation, adenosine triphosphate (ATP) breakdown implies purine metabolite accumulation, which in humans is associated with pathological conditions. Purine recycling in seals increases in response to prolonged fasting and ischemia. Concentrations of metabolites and activities of key enzymes in purine metabolism were examined in plasma and red blood cells from bottlenose dolphins (Tursiops truncatus) and humans. Hypoxanthine and inosine monophosphate concentrations were higher in plasma from dolphins than humans. Plasma hypoxanthine-guanine phosphoribosyl transferase (HGPRT) activity in dolphins suggests an elevated purine recycling rate, and a mechanism for avoiding accumulation of non-recyclable purines (xanthine and uric acid). Red blood cell concentrations of hypoxanthine, adenosine diphosphate, ATP and guanosine triphosphate were lower in dolphins than in humans; adenosine monophosphate and nicotinamide adenine dinucleotide concentrations were higher in dolphins. HGPRT activity in red blood cells was higher in humans than in dolphins. The lower concentrations of purine catabolism and recycling by-products in plasma from dolphins could be beneficial in providing substrates for recovery of ATP depleted during diving or vigorous swimming. These results suggest that purine salvage in dolphins could be a mechanism for delivering nucleotide precursors to tissues with high ATP and guanosine triphosphate requirements. PMID:27375492

  5. Conserved Residues in the Subunit Interface of tau Glutathione S-transferase Affect Catalytic and Structural Functions

    Institute of Scientific and Technical Information of China (English)

    Cai-Ling Wang; Hai-Ling Yang

    2011-01-01

    The tau class glutathione S-transferases(GSTs)have important roles in stress tolerance and the detoxification of herbicides in crops and weeds.Structural investigations of a wheat tau GST(TaGSTU4) show two subunit interactions:a hydrogen bond between the Tyr93 and Pro65 from another subunit of the dimer,and two salt bridges between residues Glu78 and side chains of Arg95 and Arg99 in the opposite subunit.By investigating enzyme activities,kinetic parameters and structural characterizations,this study showed the following results:(i)the hydrogen bond interaction between the Tyr93 and Pro65 was not essential for dimerization,but contributed to the enzyme's catalytic activity,thermal stability and affinity towards substrates glutathione and 1-chloro-2,4-dinitrobenzene;and(ii)two salt bridges mainly contributed to the protein structure stability and catalysis.The results of this study form a structural and functional basis for rational design of more selective and environmentally friendly herbicides.

  6. Membrane-bound catechol-O-methyl transferase in cortical neurons and glial cells is intracellularly oriented

    Directory of Open Access Journals (Sweden)

    Björn H Schott

    2010-10-01

    Full Text Available Catechol-O-methyl transferase (COMT is involved in the inactivation of dopamine in brain regions in which the dopamine transporter (DAT1 is sparsely expressed. The membrane-bound isoform of COMT (MB-COMT is the predominantly expressed form in the mammalian central nervous system (CNS. It has been a matter of debate whether in neural cells of the CNS the enzymatic domain of MB-COMT is oriented towards the cytoplasmic or the extracellular compartment. Here we used live immunocytochemistry on cultured neocortical neurons and glial cells to investigate the expression and membrane orientation of native COMT and of transfected MB-COMT fused to green fluorescent protein (GFP. After live staining, COMT immunoreactivity was reliably detected in both neurons and glial cells after permeabilization, but not on unpermeabilized cells. Similarly, autofluorescence of COMT-GFP fusion protein and antibody fluorescence showed overlap only in permeabilized neurons. Our data provide converging evidence for an intracellular membrane orientation of MB-COMT in neurons and glial cells, suggesting the presence of a DAT1-independent postsynaptic uptake mechanism for dopamine, prior to its degradation via COMT.

  7. Production of fructosyl transferase by Aspergillus oryzae CFR 202 in solid-state fermentation using agricultural by-products.

    Science.gov (United States)

    Sangeetha, P T; Ramesh, M N; Prapulla, S G

    2004-10-01

    Fructosyl transferase (FTase) production by Aspergillus oryzae CFR 202 was carried out by solid-state fermentation (SSF), using various agricultural by-products like cereal bran, corn products, sugarcane bagasse,cassava bagasse (tippi) and by-products of coffee and tea processing. The FTase produced was used for the production of fructo-oligosaccharides (FOS), using 60% sucrose as substrate. Among the cereal bran used, rice bran and wheat bran were good substrates for FTase production by A. oryzae CFR 202. Among the various corn products used, corn germ supported maximum FTase production, whereas among the by-products of coffee and tea processing used, spent coffee and spent tea were good substrates, with supplementation of yeast extract and complete synthetic media. FTase had maximum activity at 60 degrees C and pH 6.0. FTase was stable up to 40 degrees C and in the pH range 5.0-7.0. Maximum FOS production was obtained with FTase after 8 h of reaction with 60% sucrose. FTase produced by SSF using wheat bran was purified 107-fold by ammonium sulphate precipitation (30-80%), DEAE cellulose chromatography and Sephadex G-200 chromatography. The molecular mass of the purified FTase was 116.3 kDa by SDS-PAGE. This study indicates the potential for the use of agricultural by-products for the efficient production of FTase enzyme by A. oryzae CFR 202 in SSF, thereby resulting in value addition of those by-products.

  8. Proteomic Profiling of Cytosolic Glutathione Transferases from Three Bivalve Species: Corbicula fluminea, Mytilus galloprovincialis and Anodonta cygnea

    Directory of Open Access Journals (Sweden)

    José Carlos Martins

    2014-01-01

    Full Text Available Suspension-feeding bivalves are considered efficient toxin vectors with a relative insensitivity to toxicants compared to other aquatic organisms. This fact highlights the potential role of detoxification enzymes, such as glutathione transferases (GSTs, in this bivalve resistance. Nevertheless, the GST system has not been extensively described in these organisms. In the present study, cytosolic GSTs isoforms (cGST were surveyed in three bivalves with different habitats and life strategies: Corbicula fluminea, Anodonta cygnea and Mytilus galloprovincialis. GSTs were purified by glutathione-agarose affinity chromatography, and the collection of expressed cGST classes of each bivalve were identified using a proteomic approach. All the purified extracts were also characterized kinetically. Results reveal variations in cGST subunits collection (diversity and properties between the three tested bivalves. Using proteomics, four pi-class and two sigma-class GST subunits were identified in M. galloprovincialis. C. fluminea also yielded four pi-class and one sigma-class GST subunits. For A. cygnea, two mu-class and one pi-class GST subunits were identified, these being the first record of GSTs from these freshwater mussels. The affinity purified extracts also show differences regarding enzymatic behavior among species. The variations found in cGST collection and kinetics might justify diverse selective advantages for each bivalve organism.

  9. Problematic detoxification of estrogen quinones by NAD(P)H-dependent quinone oxidoreductase and glutathione-S-transferase.

    Science.gov (United States)

    Chandrasena, R Esala P; Edirisinghe, Praneeth D; Bolton, Judy L; Thatcher, Gregory R J

    2008-07-01

    Estrogen exposure through early menarche, late menopause, and hormone replacement therapy increases the risk factor for hormone-dependent cancers. Although the molecular mechanisms are not completely established, DNA damage by quinone electrophilic reactive intermediates, derived from estrogen oxidative metabolism, is strongly implicated. A current hypothesis has 4-hydroxyestrone-o-quinone (4-OQE) acting as the proximal estrogen carcinogen, forming depurinating DNA adducts via Michael addition. One aspect of this hypothesis posits a key role for NAD(P)H-dependent quinone oxidoreductase (NQO1) in the reduction of 4-OQE and protection against estrogen carcinogenesis, despite two reports that 4-OQE is not a substrate for NQO1. 4-OQE is rapidly and efficiently trapped by GSH, allowing measurement of NADPH-dependent reduction of 4-OQE in the presence and absence of NQO1. 4-OQE was observed to be a substrate for NQO1, but the acceleration of NADPH-dependent reduction by NQO1 over the nonenzymic reaction is less than 10-fold and at more relevant nanomolar concentrations of substrate is less than 2-fold. An alternative detoxifying enzyme, glutathione-S-transferase, was observed to be a target for 4-OQE, rapidly undergoing covalent modification. These results indicate that a key role for NQO1 and GST in direct detoxification of 4-hydroxy-estrogen quinones is problematic. PMID:18588320

  10. Overexpression of glutathione transferase E7 in Drosophila differentially impacts toxicity of organic isothiocyanates in males and females.

    Directory of Open Access Journals (Sweden)

    Aslam M A Mazari

    Full Text Available Organic isothiocyanates (ITCs are allelochemicals produced by plants in order to combat insects and other herbivores. The compounds are toxic electrophiles that can be inactivated and conjugated with intracellular glutathione in reactions catalyzed by glutathione transferases (GSTs. The Drosophila melanogaster GSTE7 was heterologously expressed in Escherichia coli and purified for functional studies. The enzyme showed high catalytic activity with various isothiocyanates including phenethyl isothiocyanate (PEITC and allyl isothiocyanate (AITC, which in millimolar dietary concentrations conferred toxicity to adult D. melanogaster leading to death or a shortened life-span of the flies. In situ hybridization revealed a maternal contribution of GSTE7 transcripts to embryos, and strongest zygotic expression in the digestive tract. Transgenesis involving the GSTE7 gene controlled by an actin promoter produced viable flies expressing the GSTE7 transcript ubiquitously. Transgenic females show a significantly increased survival when subjected to the same PEITC treatment as the wild-type flies. By contrast, transgenic male flies show a significantly lower survival rate. Oviposition activity was enhanced in transgenic flies. The effect was significant in transgenic females reared in the absence of ITCs as well as in the presence of 0.15 mM PEITC or 1 mM AITC. Thus the GSTE7 transgene elicits responses to exposure to ITC allelochemicals which differentially affect life-span and fecundity of male and female flies.

  11. Proanthocyanidins inhibit Ascaris suum glutathione-S-transferase activity and increase susceptibility of larvae to levamisole in vitro.

    Science.gov (United States)

    Hansen, Tina V A; Fryganas, Christos; Acevedo, Nathalie; Caraballo, Luis; Thamsborg, Stig M; Mueller-Harvey, Irene; Williams, Andrew R

    2016-08-01

    Proanthocyanidins (PAC) are a class of plant secondary metabolites commonly found in the diet that have shown potential to control gastrointestinal nematode infections. The anti-parasitic mechanism(s) of PAC remain obscure, however the protein-binding properties of PAC suggest that disturbance of key enzyme functions may be a potential mode of action. Glutathione-S-transferases (GSTs) are essential for parasite detoxification and have been investigated as drug and vaccine targets. Here, we show that purified PAC strongly inhibit the activity of both recombinant and native GSTs from the parasitic nematode Ascaris suum. As GSTs are involved in detoxifying xenobiotic substances within the parasite, we hypothesised that this inhibition may render parasites hyper-susceptible to anthelmintic drugs. Migration inhibition assays with A. suum larvae demonstrated that the potency of levamisole (LEV) and ivermectin (IVM) were significantly increased in the presence of PAC purified from pine bark (4.6-fold and 3.2-fold reduction in IC50 value for LEV and IVM, respectively). Synergy analysis revealed that the relationship between PAC and LEV appeared to be synergistic in nature, suggesting a specific enhancement of LEV activity, whilst the relationship between PAC and IVM was additive rather than synergistic, suggesting independent actions. Our results demonstrate that these common dietary compounds may increase the efficacy of synthetic anthelmintic drugs in vitro, and also suggest one possible mechanism for their well-known anti-parasitic activity.

  12. Identification and Characterization of Seven Glutathione S-Transferase Genes from Citrus Red Mite, Panonychus citri (McGregor

    Directory of Open Access Journals (Sweden)

    Chong-Yu Liao

    2013-12-01

    Full Text Available The citrus red mite, Panonychus citri (McGregor, is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed that the seven GSTs genes in P. citri cloned in this study belong to three different cytosolic classes, including four in mu, two in delta and one in zeta. Among these seven GSTs genes, the relative expression level of PcGSTm1 was significantly higher in adult than in the other life stages (egg, larvae and nymph. Compared with the control, the mRNA levels of the seven GST genes did not change significantly following exposure to pyridaben at LC10. However, RT-qPCR results showed that, when exposed to LC10 of fenpropathrin, six GSTs gene (PcGSTm1, PcGSTm3, PcGSTm4, PcGSTd1, PcGSTd2 and PcGSTz1 transcripts increased in a time-dependent manner. This is the first insight into the molecular characteristics of GSTs gene cDNAs in P. citri. The elevated GSTs gene transcripts following exposure to fenpropathrin might be one of the mechanisms involved in detoxification of this acaricide.

  13. Identification and characterization of seven glutathione S-transferase genes from citrus red mite, Panonychus citri (McGregor).

    Science.gov (United States)

    Liao, Chong-Yu; Zhang, Kun; Niu, Jin-Zhi; Ding, Tian-Bo; Zhong, Rui; Xia, Wen-Kai; Dou, Wei; Wang, Jin-Jun

    2013-01-01

    The citrus red mite, Panonychus citri (McGregor), is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs) genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed that the seven GSTs genes in P. citri cloned in this study belong to three different cytosolic classes, including four in mu, two in delta and one in zeta. Among these seven GSTs genes, the relative expression level of PcGSTm1 was significantly higher in adult than in the other life stages (egg, larvae and nymph). Compared with the control, the mRNA levels of the seven GST genes did not change significantly following exposure to pyridaben at LC10. However, RT-qPCR results showed that, when exposed to LC10 of fenpropathrin, six GSTs gene (PcGSTm1, PcGSTm3, PcGSTm4, PcGSTd1, PcGSTd2 and PcGSTz1) transcripts increased in a time-dependent manner. This is the first insight into the molecular characteristics of GSTs gene cDNAs in P. citri. The elevated GSTs gene transcripts following exposure to fenpropathrin might be one of the mechanisms involved in detoxification of this acaricide. PMID:24351815

  14. Activity Based High-Throughput Screening for Novel O-GlcNAc Transferase Substrates Using a Dynamic Peptide Microarray.

    Directory of Open Access Journals (Sweden)

    Jie Shi

    Full Text Available O-GlcNAcylation is a reversible and dynamic protein post-translational modification in mammalian cells. The O-GlcNAc cycle is catalyzed by O-GlcNAc transferase (OGT and O-GlcNAcase (OGA. O-GlcNAcylation plays important role in many vital cellular events including transcription, cell cycle regulation, stress response and protein degradation, and altered O-GlcNAcylation has long been implicated in cancer, diabetes and neurodegenerative diseases. Recently, numerous approaches have been developed to identify OGT substrates and study their function, but there is still a strong demand for highly efficient techniques. Here we demonstrated the utility of the peptide microarray approach to discover novel OGT substrates and study its specificity. Interestingly, the protein RBL-2, which is a key regulator of entry into cell division and may function as a tumor suppressor, was identified as a substrate for three isoforms of OGT. Using peptide Ala scanning, we found Ser 420 is one possible O-GlcNAc site in RBL-2. Moreover, substitution of Ser 420, on its own, inhibited OGT activity, raising the possibility of mechanism-based development for selective OGT inhibitors. This approach will prove useful for both discovery of novel OGT substrates and studying OGT specificity.

  15. Sphingobium sp. SYK-6 LigG involved in lignin degradation is structurally and biochemically related to the glutathione transferase ω class.

    Science.gov (United States)

    Meux, Edgar; Prosper, Pascalita; Masai, Eiji; Mulliert, Guillermo; Dumarçay, Stéphane; Morel, Mélanie; Didierjean, Claude; Gelhaye, Eric; Favier, Frédérique

    2012-11-16

    SpLigG is one of the three glutathione transferases (GSTs) involved in the process of lignin breakdown in the soil bacterium Sphingobium sp. SYK-6. Sequence comparisons showed that SpLigG and several proteobacteria homologues form an independent cluster within cysteine-containing GSTs. The relationship between SpLigG and other GSTs was investigated. The X-ray structure and biochemical properties of SpLigG indicate that this enzyme belongs to the omega class of glutathione transferases. However, the hydrophilic substrate binding site of SpLigG, together with its known ability to stereoselectively deglutathionylate the physiological substrate α-glutathionyl-β-hydroxypropiovanillone, argues for broadening the definition of the omega class.

  16. Glutathione S-transferase activity and isoenzyme composition in benign ovarian tumours, untreated malignant ovarian tumours, and malignant ovarian tumours after platinum/cyclophosphamide chemotherapy.

    OpenAIRE

    Zee, A.G. Van der; van Ommen, B.; Meijer, C; Hollema, H; Bladeren, P.J. van; de Vries, E. G.

    1992-01-01

    Glutathione S-transferase (GST) isoenzyme composition, isoenzyme quantities and enzymatic activity were investigated in benign (n = 4) ovarian tumours and malignant ovarian tumours, before (n = 20) and after (n = 16) chemotherapy. Enzymatic activity of GST in cytosols was measured by determining 1-chloro-2,4-dinitrobenzene conjugation with glutathione, cytosolic GST subunits were determined by wide pore reversed phase HPLC, using a S-hexylglutathione-agarose affinity column, and isoelectric f...

  17. Tissue and Life Stage Specificity of Glutathione S-Transferase Expression in the Hessian Fly, Mayetiola destructor: Implications for Resistance to Host Allelochemicals

    OpenAIRE

    Mittapalli, Omprakash; Neal, Jonathan J.; Shukle, Richard H

    2007-01-01

    Two new Delta and Sigma glutathione S-transferases (GSTs) in the Hessian fly, Mayetiola destructor (Diptera: Cecidomyiidae), were characterized and transcription profiles described. The deduced amino acid sequences for the two M. destructor Delta GSTs (MdesGST-1 and MdesGST-3) showed high similarity with other insect Delta GSTs including the conserved catalytic serine residue. The deduced amino acid sequence for the M. destructor Sigma GST (MdesGST-2) showed high similarity with other insect ...

  18. Loss of ICG uptake in the process of rat hepatocarcinogenesis correlates to the disappearance of glutathione-S-transferase alpha subunit.

    OpenAIRE

    Ling, Liu; Higashi,Toshihiro; Tsuchida, Shigeki; Sato, Kiyomi; Tsuji, Takao

    1993-01-01

    Reduced indocyanine green (ICG) uptake is one of the functional changes of human hepatocellular carcinoma (HCC). To clarify the mechanisms of loss of ICG uptake, and determine which subunit of glutathione-S-transferase (GST), alpha or pi, plays a role in ICG transport in hepatocytes, an experimental HCC model was developed that used nodules induced by 2-acetylamino-fluorene (2-AAF) administration. Many of the ICG stained nodules, which consisted of benign and borderline lesions, were GST-alph...

  19. Analysis of Common Mutations in the Galactose-1-Phosphate Uridyl Transferase Gene : New Assays to Increase the Sensitivity and Specificity of Newborn Screening for Galactosemia

    OpenAIRE

    Dobrowolski, Steven F.; Banas, Richard A.; Suzow, Joseph G.; Berkley, Michelle; Naylor, Edwin W.

    2003-01-01

    Classical galactosemia is a genetic disease caused by mutations in the galactose-1-phosphate uridyl transferase (GALT) gene. Prospective newborn screening for galactosemia is routine and utilizes the universally collected newborn dried blood specimen on filter paper. Screening for galactosemia is achieved through analysis of total galactose (galactose and galactose-1-phosphate) and/or determining the activity of the GALT enzyme. While this approach is effective, en vironmental factors and the...

  20. Transcriptional and Functional Analysis of Oxalyl-Coenzyme A (CoA) Decarboxylase and Formyl-CoA Transferase Genes from Lactobacillus acidophilus

    OpenAIRE

    Azcarate-Peril, M. Andrea; Bruno-Bárcena, Jose M.; Hassan, Hosni M.; Klaenhammer, Todd R.

    2006-01-01

    Oxalic acid is found in dietary sources (such as coffee, tea, and chocolate) or is produced by the intestinal microflora from metabolic precursors, like ascorbic acid. In the human intestine, oxalate may combine with calcium, sodium, magnesium, or potassium to form less soluble salts, which can cause pathological disorders such as hyperoxaluria, urolithiasis, and renal failure in humans. In this study, an operon containing genes homologous to a formyl coenzyme A transferase gene (frc) and an ...

  1. Glutathione-S-transferase subtypes α and π as a tool to predict and monitor graft failure or regeneration in a pilot study of living donor liver transplantation

    OpenAIRE

    Jochum C; Beste M; Sowa J-P; Farahani MS; Penndorf V; Nadalin S; Saner F; Canbay A; Gerken G

    2011-01-01

    Abstract Objective Glutathione-S-Transferase (GST) subtype α and π are differentially expressed in adult liver tissue. Objective of the study was if GST α and p may serve as predictive markers for liver surgery, especially transplantations. Methods 13 patients receiving living donor liver transplantation (LDLT) and their corresponding donors were analyzed for standard serum parameters (ALT, AST, gGT, bilirubin) as well as GST-α and -π before LDLT and daily for 10 days after LDLT. Patients (R)...

  2. Elevated Levels of Urinary 8-Hydroxy-2′-deoxyguanosine, Lymphocytic Micronuclei, and Serum Glutathione S-Transferase in Workers Exposed to Coke Oven Emissions

    OpenAIRE

    Liu, Ai-Lin; Lu, Wen-Qing; Wang, Zeng-Zhen; Chen, Wei-Hong; Lu, Wen-Hong; Yuan, Jing; Nan, Pei-Hong; Sun, Jian-Ya; Zou, Ya-Lin; Zhou, Li-Hong; Zhang, Chi; Wu, Tang-chun

    2005-01-01

    To investigate associations among occupational exposure to coke oven emissions (COEs), oxidative stress, cytogenotoxic effects, change in the metabolizing enzyme glutathione S-transferase (GST), and internal levels of polycyclic aromatic hydrocarbons (PAHs) in coke oven workers, we recruited 47 male coke oven workers and 31 male control subjects from a coke oven plant in northern China. We measured the levels of 1-hydroxypyrene (1-OHP) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in urine, micron...

  3. Decreased glutathione content and glutathione S-transferase activity in red blood cells of coal miners with early stages of pneumoconiosis.

    OpenAIRE

    Evelo, C T; Bos, R P; Borm, P J

    1993-01-01

    Blood samples of miners heavily exposed to coal dust were examined for changes in glutathione S-transferase (GST) activity. Decreased GST activity was found in red blood cells of subjects with early stages of coal workers' pneumoconiosis (International Labour Office classification 0/1-1/2) when compared with control miners. At further progression of coal workers' pneumoconiosis (> or = 2/1), the activity of GST was not different from controls. In the same group with moderate coal workers' pne...

  4. Synthetic fragments of antigenic lipophosphoglycans from Leishmania major and Leishmania mexicana and their use for characterisation of the Leishmania elongating alpha-D-mannopyranosylphosphate transferase.

    Science.gov (United States)

    Higson, Adrian P; Ross, Andrew J; Tsvetkov, Yury E; Routier, Françoise H; Sizova, Olga V; Ferguson, Michael A J; Nikolaev, Andrei V

    2005-03-18

    The phosphorylated branched heptasaccharides 7 and 8, the octasaccharide 9 and the phosphorylated trisaccharides 5 and 6, which are fragments of the phosphoglycan portion of the surface lipophosphoglycans from Leishmania mexicana (5) or L. major (6-9), were synthesised by using the glycosyl hydrogenphosphonate method for the preparation of phosphodiester bridges. The compounds were tested as acceptor substrates/putative inhibitors for the Leishmania elongating alpha-D-mannosylphosphate transferase. PMID:15685582

  5. Role of glutathione S-transferase M1, T1 and P1 gene polymorphisms in childhood acute lymphoblastic leukemia susceptibility in a Turkish population

    OpenAIRE

    Mehmet Guven; Selin Unal; Duygu Erhan; Nihal Ozdemir; Safa Baris; Tiraje Celkan; Merve Bostancı; Bahadir Batar

    2015-01-01

    The variations between different individuals in the xenobiotic metabolizing enzymes' activity were shown to modify susceptibility to childhood acute lymphoblastic leukemia (ALL). Polymorphisms associated with genes coding for the glutathione S-transferase (GST) enzyme were known to affect the metabolism of different carcinogens. The aim of this study was to evaluate the influence of the GSTM1 and GSTT1 deletion polymorphisms, and the GSTP1 Ile105Val single nucleotide polymorphism (SNP) on the...

  6. A Mannosyl Transferase Required for Lipopolysaccharide Inner Core Assembly in Rhizobium leguminosarum: Purification, substrate specificity, and expression in Salmonella waaC mutants*

    OpenAIRE

    Kanipes, Margaret I.; Ribeiro, Anthony A.; Lin, Shanhua; Cotter, Robert J.; Raetz, Christian R. H.

    2003-01-01

    The lipopolysaccharide (LPS) core domain of Gram-negative bacteria plays an important role in outer membrane stability and host interactions. Little is known about the biochemical properties of the glycosyltransferases that assemble the LPS core. We now report the purification and characterization of the Rhizobium leguminosarum mannosyl transferase LpcC, which adds a mannose unit to the inner 3-deoxy-D-manno-octulosonic acid (Kdo) moiety of the LPS precursor, Kdo2-lipid IVA. LpcC containing a...

  7. Controlled ribonucleotide tailing of cDNA ends (CRTC) by terminal deoxynucleotidyl transferase: a new approach in PCR-mediated analysis of mRNA sequences.

    OpenAIRE

    Schmidt, W. M.; Mueller, M W

    1996-01-01

    Controlled ribonucleotide tailing of cDNA ends (CRTC) by terminal deoxynucleotidyl transferase is a polymerase chain reaction (PCR)-mediated technique that was developed to facilitate cloning and direct sequence analysis of complete 5'-terminal unknown coding regions of rare RNA molecules. In contrast with standard tailing protocols using dNTPs as the substrate, ribo-tailing of cDNA ends is easily controllable, self-limited (from two to four rNMP incorporations) and highly efficient (>98%). B...

  8. Two pear glutathione S-transferases genes are regulated during fruit development and involved in response to salicylic acid, auxin, and glucose signaling.

    Directory of Open Access Journals (Sweden)

    Hai-Yan Shi

    Full Text Available Two genes encoding putative glutathione S-transferase proteins were isolated from pear (Pyrus pyrifolia and designated PpGST1 and PpGST2. The deduced PpGST1 and PpGST2 proteins contain conserved Glutathione S-transferase N-terminal domain (GST_N and Glutathione S-transferase, C-terminal domain (GST_C. Using PCR amplification technique, the genomic clones corresponding to PpGST1 and PpGST2 were isolated and shown to contain two introns and a singal intron respectively with typical GT/AG boundaries defining the splice junctions. Phylogenetic analysis clearly demonstrated that PpGST1 belonged to Phi class of GST superfamilies and had high homology with apple MdGST, while PpGST2 was classified into the Tau class of GST superfamilies. The expression of PpGST1 and PpGST2 genes was developmentally regulated in fruit. Further study demonstrated that PpGST1 and PpGST2 expression was remarkably induced by glucose, salicylic acid (SA and indole-3-aceticacid (IAA treatments in pear fruit, and in diseased fruit. These data suggested that PpGST1 and PpGST2 might be involved in response to sugar, SA, and IAA signaling during fruit development of pear.

  9. Parâmetros cinéticos da Glutationa S-Transferase e sua ativação por extratos de vegetais Kinetics parameters of Glutathione S-Transferase and its activation by vegetable extracts

    Directory of Open Access Journals (Sweden)

    Maria Célia Lopes Torres

    2004-06-01

    Full Text Available Este estudo teve como objetivos avaliar a indução da Glutationa S-Transferase, com extratos de vegetais, e caracterizar os parâmetros cinéticos desta enzima. Foram obtidos os extratos aquoso, etanólico e hexanólico de vegetais, amplamente consumidos no Brasil, como berinjela (Solanum melongena L., couve-flor (Brassica oleracea L., couve (Brassica oleracea L., brócolis (Brassica oleracea L., couve-de-bruxelas (Brassicaoleraea L., cebola (Allium cepa L., alho (Allium sativum L.; vegetais que apresentam gosto amargo, como jiló (Solanum gilo Raddi, guariroba (Syagrus oleracea Becc., mostarda (Brassica nigra L., carqueja (Cacalia spp., e de plantas relacionadas, na cultura popular, como curadoras de determinadas doenças, como a babosa (Aloe vera L.. A atividade da enzima foi determinada usando como substrato o 1 cloro 2, 4 dinitrobenzeno, na presença dos extratos vegetais. A mistura da reação, sem a presença do extrato, foi considerada controle. Das amostras de vegetais avaliadas, a berinjela, a couve e o brócolis apresentaram maior indução na atividade da GST, sendo o extrato etanólico o mais eficaz. A enzima apresentou um Vmax de 0,016 abs. min-1/unidade da enzima e um Km de 0,323mM. O baixo valor de Km encontrado indica uma alta especificidade da enzima pelo substrato 1 cloro 2, 4 dinitrobenzeno e a atividade máxima da enzima foi na faixa de pH entre 6,5 e 7,0.This study was done to evaluate induction Glutathione S-Transferase, with vegetable extracts, and characterize its kinetics parameters. The aqueous, alcoholic, and hexanoic extracts were obtained from vegetables widely consumed in Brazil: eggplant (Solanum melongena L., cauliflower (Brassica oleracea L., cauli leaves (Brassica oleracea L., broccoli (Brassica oleracea L., Brussels sprout (Brassicaoleraea L., onions (Allium cepa L., garlic (Allium sativum L.; and bitter tasting vegetable such as jiló (Solanum gilo Raddi, guariroba (Syagrus oleracea Becc., black mustard

  10. Feruloylated Soybean Oil: Novel Soy-Based Cosmeceuticals

    Science.gov (United States)

    We have synthesized novel, lipid-based cosmeceutical ingredients by incorporating ferulic acid onto the glycerol backbone of soybean oil. Ferulic acid is present in nature esterified to other plant components, such as the hemicellulose and lignin fractions of plant cell walls, as well as in the wax...

  11. Green processing for commercial production of feruloylated vegetable oils

    Science.gov (United States)

    Covalent incorporation of ferulic acid into vegetable oils produces a desirable product for cosmetic applications. Current practice involves the biocatalytic transesterification of ethyl ferulate with soybean oil, followed by a molecular distillation step to remove unconsumed ethyl ferulate and the...

  12. Systemic catechol-O-methyl transferase inhibition enables the D1 agonist radiotracer R-[11C]SKF 82957

    International Nuclear Information System (INIS)

    Introduction: R-[11C]-SKF 82957 is a high-affinity and potent dopamine D1 receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway, facilitating the use of R-[11C]-SKF 82957 to image the high-affinity state of the dopamine D1 receptor with PET. Methods: R-[11C]SKF 82957 was administered to untreated and COMT inhibitor-treated conscious rats, and the radioactive metabolites present in the brain and plasma were quantified by HPLC. Under optimal conditions, cerebral uptake and dopamine D1 binding of R-[11C]SKF 82957 were measured ex vivo. In addition, pharmacological challenges with the receptor antagonist SCH 23390, amphetamine, the dopamine reuptake inhibitor RTI-32 and the dopamine hydroxylase inhibitor α-methyl-p-tyrosine were performed to study the specificity and sensitivity of R-[11C]-SKF 82957 dopamine D1 binding in COMT-inhibited animals. Results: Treatment with the COMT inhibitor tolcapone was associated with a dose-dependent (EC90 5.3±4.3 mg/kg) reduction in the lipophilic metabolite. Tolcapone treatment (20 mg/kg) also resulted in a significant increase in the striatum/cerebellum ratio of R-[11C]SKF 82957, from 15 (controls) to 24. Treatment with the dopamine D1 antagonist SCH 23390 reduced the striatal binding to the levels of the cerebellum, demonstrating a high specificity and selectivity of R-[11C]SKF 82957 binding. Conclusions: Pre-treatment with the COMT inhibitor tolcapone inhibits formation of an interfering metabolite of R-[11C]SKF 82957. Under such conditions, R-[11C]SKF 82957 demonstrates high potential as the first agonist radiotracer for imaging the dopamine D1 receptor by PET.

  13. CYP-dependent induction of glutathione S-transferase in Daphnia similis exposed to a disperse azo dye.

    Science.gov (United States)

    Yu, Tsai Hsin; Dafre, Alcir Luiz; de Aragão Umbuzeiro, Gisela; Franciscon, Elisangela

    2015-01-01

    Disperse Red 1 (DR1) is an azo dye that can reach the aquatic environment through the discharge of textile industrial wastewaters. It has been tested in Daphnia similis and shown to be highly toxic. Cytochrome P450 (CYP) is a class of enzymes involved in phase I of detoxification, while glutathione S-transferase (GST) are a class of phase II enzymes. No information about phase I or II dye metabolism in microcrustacea were found in the literature. In this study we identified CYP and GST enzymes involved in the metabolism of DR1 in juveniles of D. similis. Using spectrophotometric analysis we showed that 50 % of the dye was absorbed by the organisms, which could be confirmed by the reddish color of animals exposed to DR1, however adsorption cannot be ruled out. GST activity increased from 280 to 615 nmol(-1 )min(-1 )mg when D. similis were exposed for 48 h to 0.2 mg L(-1) DR1 and from 274 to 815 nmol(-1) min(-1 )mg when exposed to 5 mg L(-1). Data clearly demonstrate that exposure to DR1 can stimulate a strong induction of GST activity, whose participation in DR1 metabolism needs to be confirmed. The induction of GST activity seems to be dependent on CYP activity, since treatment with SKF535A, a CYP inhibitor, blocked the DR1-dependent GST induction. We speculate that GST is involved in DR1 metabolism in Daphnia and that CYP activity is necessary to induce GST-activity, which is an indirect evidence of its role in the biotransformation of DR1.

  14. Purification of Glutathione S-Transferase pi from Erythrocytes and Evaluation of the Inhibitory Effect of Hypericin.

    Science.gov (United States)

    Turk, Seyhan; Kulaksiz Erkmen, Gulnihal; Dalmizrak, Ozlem; Ogus, I Hamdi; Ozer, Nazmi

    2015-12-01

    Hypericin is a photosensitizer compound used in the photodynamic therapy (PDT). PDT is an alternative cancer treatment strategy whose function is dependent on the photosensitizers accumulating selectively in tumor cells and following visible or infra-red light induced activation lead to the apoptosis/necrosis of the tumor cells via the formation of reactive oxygen species. Thus, the cellular redox balance is essential for the efficacy of PDT. Among the protective enzyme systems glutathione S-transferases (GST, E.C.2.5.1.18) function in detoxification, protection against oxidative stress and intracellular transport of molecules. It is known that isoenzymes of GST and especially GST-pi is increased in cancer cells and it plays very important functions in the development of resistance to anticancer drugs. Since photosensitizers are used intravenously, it is important to elucidate the effects of photosensitizers on the erythrocyte enzymes. The aim of the present study was to investigate the impact of hypericin on human erythrocyte GST-pi (heGST-pi). Purification yield of 71% and purification fold of 2550 were achieved by using conventional chromatographic methods. The specific activity of the enzyme is found as 51 U/mg protein. Hypericin inhibited heGST-pi in a dose dependent manner and inhibition was biphasic. Noncompetitive type of inhibition was observed with both substrates, GSH and CDNB. The inhibitory constant (K i ) values obtained from Lineweaver-Burk, Dixon, secondary plots; slope and y-intercept versus 1/S (substrate) and from non-linear regression analysis were in good correlation: K i (GSH) was calculated as 0.19 ± 0.01 μM and K i (CDNB) as 0.26 ± 0.03 μM. PMID:26614503

  15. Transcriptional profiles of glutathione-S-Transferase isoforms, Cyp, and AOE genes in atrazine-exposed zebrafish embryos.

    Science.gov (United States)

    Glisic, Branka; Hrubik, Jelena; Fa, Svetlana; Dopudj, Nela; Kovacevic, Radmila; Andric, Nebojsa

    2016-02-01

    Glutathione-S-transferase (GST) superfamily consists of multiple members involved in xenobiotic metabolism. Expressional pattern of the GST isoforms in adult fish has been used as a biomarker of exposure to environmental chemicals. However, GST transcriptional responses vary across organs, thus requiring a cross-tissue examination of multiple mRNAs for GST profiling in an animal after chemical exposure. Zebrafish embryos express all GST isoforms as adult fish and could therefore represent an alternative model for identification of biomarkers of exposure. To evaluate such a possibility, we studied a set of cytosolic and microsomal GST isoform-specific expression profiles in the zebrafish embryos after exposure to atrazine, a widely used herbicide. Expression of the GST isoforms was compared with that of CYP genes involved in the phase I of xenobiotic metabolism and antioxidant enzyme (AOE) genes. Using quantitative real-time PCR, we showed dynamic changes in the expressional pattern of twenty GST isoforms, cyp1a, cyp3a65, ahr2, and four AOEs in early development of zebrafish. Acute (48 and 72 h) exposure of 24 h-old embryos to atrazine, from environmentally relevant (0.005 mg/L) to high (40 mg/L) concentrations, caused a variety of transient, albeit minor changes (GST isoforms, ahr2 and AOE genes response. However, expression of cyp1a and cyp3a65 mRNA was markedly and consistently induced by high doses of atrazine (5 and 40 mg/L). In summary, an analysis of the response of multiple systems in the zebrafish embryos provided a comprehensive understanding of atrazine toxicity and its potential impact on biological processes. PMID:25158112

  16. Influence of glutathione-S-transferase (GST) inhibition on lung epithelial cell injury: role of oxidative stress and metabolism.

    Science.gov (United States)

    Fletcher, Marianne E; Boshier, Piers R; Wakabayashi, Kenji; Keun, Hector C; Smolenski, Ryszard T; Kirkham, Paul A; Adcock, Ian M; Barton, Paul J; Takata, Masao; Marczin, Nandor

    2015-06-15

    Oxidant-mediated tissue injury is key to the pathogenesis of acute lung injury. Glutathione-S-transferases (GSTs) are important detoxifying enzymes that catalyze the conjugation of glutathione with toxic oxidant compounds and are associated with acute and chronic inflammatory lung diseases. We hypothesized that attenuation of cellular GST enzymes would augment intracellular oxidative and metabolic stress and induce lung cell injury. Treatment of murine lung epithelial cells with GST inhibitors, ethacrynic acid (EA), and caffeic acid compromised lung epithelial cell viability in a concentration-dependent manner. These inhibitors also potentiated cell injury induced by hydrogen peroxide (H2O2), tert-butyl-hydroperoxide, and hypoxia and reoxygenation (HR). SiRNA-mediated attenuation of GST-π but not GST-μ expression reduced cell viability and significantly enhanced stress (H2O2/HR)-induced injury. GST inhibitors also induced intracellular oxidative stress (measured by dihydrorhodamine 123 and dichlorofluorescein fluorescence), caused alterations in overall intracellular redox status (as evidenced by NAD(+)/NADH ratios), and increased protein carbonyl formation. Furthermore, the antioxidant N-acetylcysteine completely prevented EA-induced oxidative stress and cytotoxicity. Whereas EA had no effect on mitochondrial energetics, it significantly altered cellular metabolic profile. To explore the physiological impact of these cellular events, we used an ex vivo mouse-isolated perfused lung model. Supplementation of perfusate with EA markedly affected lung mechanics and significantly increased lung permeability. The results of our combined genetic, pharmacological, and metabolic studies on multiple platforms suggest the importance of GST enzymes, specifically GST-π, in the cellular and whole lung response to acute oxidative and metabolic stress. These may have important clinical implications. PMID:26078397

  17. Glutathione S transferase (GSTP 1, GSTM 1, and GSTT 1 gene polymorphisms in Egyptian patients with acute myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Aml S Nasr

    2015-01-01

    Full Text Available BACKGROUND: The super family of glutathione S-transferases (GSTs is composed of multiple isoenzymes with significant evidence of functional polymorphic variation. GSTs detoxify potentially mutagenic and toxic DNA-reactive electrophiles, including metabolites of several chemotherapeutic agents, some of which are suspected human carcinogens. Polymorphisms within the phase II metabolizer enzymes GST T1, GST M1, and GST P1 affect the body's ability to detoxify a range of potential leukemogens encountered in the environment. AIM OF WORK: To address how differences in the human GST isoenzyme expression patterns influence cancer susceptibility, prognosis, and treatment. PATIENTS AND METHODS: A total of 50 patients with acute myeloid leukemia (AML, as well as 50 age and sex matched apparently healthy volunteers were genotyped for GSTP 1, GSTM 1, and GSTT 1 gene polymorphisms using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP and conventional polymerase chain reaction (PCR, respectively. RESULTS: For GSTP1 313 A → G (GSTP1 Ile105Val polymorphism, It was found that the wild genotype (AA was significantly higher among control subjects (P value = 0.0277, while the frequency of heteromutant genotype (AG and mutant G allele (AG + GG was significantly higher among patients (P value = 0.0402, P value = 0.0277, respectively. For GSTM1 and GSTT1gene, we found statistically significantly higher frequency among patients regarding homozygous gene deletion (P value = 0.0005. CONCLUSION: We demonstrated that GSTM1 null or GSTT1 null genotypes may be considered independent risk factors for AML with no impact on prognosis and GSTP1 * 105 genotype is a prognostic factor, adding independent information to the routine laboratory parameters and cytogenetic and molecular alterations of the tumor cells.

  18. Glutathione S-transferase M1, T1 and P1 polymorphisms: susceptibility and outcome in lung cancer patients.

    Science.gov (United States)

    Sreeja, Leelakumari; Syamala, Vani; Hariharan, Sreedharan; Syamala, Volga S; Raveendran, Praveenkumar B; Sivanandan, C D; Madhavan, Jayaprakash; Ankathil, Ravindran

    2008-01-01

    The glutathione S-transferases (GSTs) are a superfamily of genes whose products are phase II enzymes, catalyzing the conjugation of reactive intermediates to soluble glutathione. Some of the GSTs are polymorphic and may play a role in lung cancer susceptibility. We investigated whether genetic polymorphisms of GSTM1, GSTP1 and GSTT1 genes modulated lung cancer risk and affect survival among lung cancer patients. We determined the GST genotypes in 422 study subjects, using polymerase chain reaction (PCR) and reverse PCR and restriction fragment length polymorphism (RFLP). Logistic Regression analysis was carried out to find the association of various polymorphisms and GSTs and lung cancer. The influence of the genetic polymorphisms on patient survival was estimated using the method of Kaplan-Meier survival function. Cox Proportional Hazard models were used to estimate hazard ratios (HR) for deaths. GSTT1 -/- genotype conferred a higher odds ratio of 2.9 (P = 0.001) compared to the GSTT1+/+. So also, the GSTP1 GG genotype too had higher risk compared to the GSTP1 AA genotype (OR = 2.3, P = 0.033). When the combined GST M1, GSTT1 and GSTP1 genotypes were examined, patients with the combinations GSTM1 null and GSTT1 null had a significant OR of 3.6. So also the combinations GSTT1-/- GSTP1 AA (P = 0.005) and GSTT1-/- GSTP1 AG/GG (P = 0.001) came out to be significant. There were some significant interactions between GST genotypes with tobacco smoking and also for clinicopathological factors. Regarding survival analysis, no association of GSTM1 or GSTP1 genes with survival was noted. The GSTT1 -/- genotype along with stage was significantly associated with overall survival and found to be an independent prognostic factors for shorter lung cancer survival. PMID:18472644

  19. Cloning and identification of four Mu-type glutathione S-transferases from the giant freshwater prawn Macrobrachium rosenbergii.

    Science.gov (United States)

    Hui, Kai-Min; Hao, Fang-Yuan; Li, Wen; Zhang, Zhao; Zhang, Chi-Yu; Wang, Wen; Ren, Qian

    2013-08-01

    Glutathione S-transferases (GSTs) are essential components of the cellular detoxification system because of their capability to protect organisms against the toxicity of reactive oxygen species (ROSs). Four different GSTs (MrMuGST1-MrMuGST4) showing similarities with Mu-type GSTs were cloned from the hepatopancreas of Macrobrachium rosenbergii. These four GSTs have 219, 216, 218 and 219 amino acids in length, respectively. MrMuGST1-MrMuGST4 proteins all have a G-site in the N-terminus and an H-site in the C-terminus. Phylogenetic analysis reveals that four Mu-type GSTs are classified into two different clades (MrMuGST2 one clade; MrMuGST1, MrMuGST3 and MrMuGST4 other clades). Nonetheless, no site under positive selection was detected but rapid evolution was found in the few of MuGST genes. Reverse transcription-polymerase chain reaction (RT-PCR) results showed that MrMuGST1 and MrMuGST2 transcripts were expressed in all detected tissues, however, MrMuGST3 and MrMuGST4 were just mainly expressed in hepatopancreas and intestines. Quantitative RT-PCR analysis showed that MrMuGST1 and MrMuGST2 were down-regulated upon Vibrio anguillarum challenge, whereas MrMuGST3 and MrMuGST4 were quickly up-regulated 2 h after the Vibrio challenge. Our results imply that different Mu-type GSTs may respond to Vibrio challenge with different manners.

  20. Weekly paclitaxel, gemcitabine, and external irradiation followed by randomized farnesyl transferase inhibitor R115777 for locally advanced pancreatic cancer

    Science.gov (United States)

    Rich, Tyvin A; Winter, Kathryn; Safran, Howard; Hoffman, John P; Erickson, Beth; Anne, Pramila R; Myerson, Robert J; Cline-Burkhardt, Vivian JM; Perez, Kimberly; Willett, Christopher

    2012-01-01

    Purpose The Radiation Therapy Oncology Group (RTOG) multi-institutional Phase II study 98-12, evaluating paclitaxel and concurrent radiation (RT) for locally advanced pancreatic cancer, demonstrated a median survival of 11.3 months and a 1-year survival of 43%. The purpose of the randomized Phase II study by RTOG 0020 was to evaluate the addition of weekly low- dose gemcitabine with concurrent paclitaxel/RT and to evaluate the efficacy and safety of the farnesyl transferase inhibitor R115777 following chemoradiation. Patients and methods Patients with unresectable, nonmetastatic adenocarcinoma of the pancreas were eligible. Patients in Arm 1 received gemcitabine, 75 mg/m2/week, and paclitaxel, 40 mg/m2/week, for 6 weeks, with 50.4 Gy radiation (CXRT). Patients in Arm 2 received an identical chemoradiation regimen but then received maintenance R115777, 300 mg twice a day for 21 days every 28 days (CXRT+R115777), until disease progression or unacceptable toxicity. Results One hundred ninety-five patients were entered into this study, and 184 were analyzable. Grade 4 nonhematologic toxicities occurred in less than 5% of CXRT patients. The most common grade 3/4 toxicity from R115777 was myelosuppression; however, grade 3/4 hepatic, metabolic, musculoskeletal, and neurologic toxicities were also reported. The median survival time was 11.5 months and 8.9 months for the CXRT and CXRT+R115777 arms, respectively. Conclusions The CXRT arm achieved a median survival of almost 1-year, supporting chemoradiation as an important therapeutic modality for locally advanced pancreatic cancer. Maintenance R115777 is not effective and is associated with a broad range of toxicities. These findings provide clinical evidence that inhibition of farnesylation affects many metabolic pathways, underscoring the challenge of developing an effective K-ras inhibitor. PMID:22977306