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Nathalie Juge - One of the best experts on this subject based on the ideXlab platform.
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Behaviour of family 10 and 11 Xylanases towards arabinoxylans with varying structure
Journal of the Science of Food and Agriculture, 2006Co-Authors: Estelle Bonnin, Stéphanie Daviet, Jens F. Sørensen, Andrew J. Goldson, Ole Sibbesen, Nathalie Juge, Luc SaulnierAbstract:The effect of arabinoxylan structure on Xylanase activity was investigated using a range of water-soluble and water-insoluble substrates isolated from wheat flour and several Xylanases from families 10 and 11 of the glycoside hydrolases. The arabinose content of the substrates affected the activity in a linear manner related to the arabinose:xylose ratio and to different extents depending on the specificity of the Xylanase. The soluble/insoluble feature of the substrates had a strong impact on the enzymatic activity and different selectivities (activity on insoluble arabinoxylan vs. activity on soluble arabinoxylan) were observed. There was no relationship between specificity and selectivity of a given Xylanase.
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emergence of a subfamily of Xylanase inhibitors within glycoside hydrolase family 18
FEBS Journal, 2005Co-Authors: Anne Durand, Ruth Flatman, Richard K. Hughes, Alain Roussel, Nathalie Juge, Bernard HenrissatAbstract:The Xylanase inhibitor protein I (XIP-I), recently identified in wheat, inhibits Xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). Sequence and structural similarities indicate that XIP-I is related to chitinases of family GH18, despite its lack of enzymatic activity. Here we report the identification and biochemical characterization of a XIP-type inhibitor from rice. Despite its initial classification as a chitinase, the rice inhibitor does not exhibit chitinolytic activity but shows specificities towards fungal GH11 Xylanases similar to that of its wheat counterpart. This, together, with an analysis of approximately 150 plant members of glycosidase family GH18 provides compelling evidence that Xylanase inhibitors are largely represented in this family, and that this novel function has recently emerged based on a common scaffold. The plurifunctionality of GH18 members has major implications for genomic annotations and predicted gene function. This study provides new information which will lead to a better understanding of the biological significance of a number of GH18 ‘inactivated’ chitinases.
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the dual nature of the wheat Xylanase protein inhibitor xip i structural basis for the inhibition of family 10 and family 11 Xylanases
Journal of Biological Chemistry, 2004Co-Authors: Francoise Payan, Anne Durand, Philippe Leone, S Porciero, Caroline S M Furniss, T Tahir, Gary Williamson, Paloma Manzanares, Harry J Gilbert, Nathalie JugeAbstract:Abstract The Xylanase inhibitor protein I (XIP-I) from wheat Triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal Xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). The crystal structures of XIP-I in complex with Aspergillus nidulans (GH10) and Penicillium funiculosum (GH11) Xylanases have been solved at 1.7 and 2.5 A resolution, respectively. The inhibition strategy is novel because XIP-I possesses two independent enzyme-binding sites, allowing binding to two glycoside hydrolases that display a different fold. Inhibition of the GH11 Xylanase is mediated by the insertion of an XIP-I Π-shaped loop (Lα4β5) into the enzyme active site, whereas residues in the helix α7 of XIP-I, pointing into the four central active site subsites, are mainly responsible for the reversible inactivation of GH10 Xylanases. The XIP-I strategy for inhibition of Xylanases involves substrate-mimetic contacts and interactions occluding the active site. The structural determinants of XIP-I specificity demonstrate that the inhibitor is able to interact with GH10 and GH11 Xylanases of both fungal and bacterial origin. The biological role of the Xylanase inhibitors is discussed in light of the present structural data.
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Specificity of feruloyl esterases for water-extractable and water-unextractable feruloylated polysaccharides: influence of Xylanase
Journal of Cereal Science, 2003Co-Authors: Craig B. Faulds, Nathalie Juge, Dario Zanichelli, Valerie F. Crepin, Ian F. Connerton, Mahalingeshwara K Bhat, Keith W. WaldronAbstract:Representatives of three types of feruloyl esterases were examined for their ability to release mono- and di-meric ferulic acid from water-extractable and water-unextractable cereal cell wall material, either alone or in the presence of a family 10 or family 11 Xylanase. A type-C feruloyl esterase from Talaromyces stipitatus (TsFaeC) released 100% of the ferulic acid from water-extractable wheat endosperm arabinoxylan when acting in combination with a Xylanase from Trichoderma longibrachiatum. The type-A esterase from Aspergillus niger, AnFaeA, was most effective in releasing ferulic acid from wheat bran and brewers' spent grain, with over 50% of the available ferulic acid being released from wheat bran in the presence of a Xylanase from Bacillus subtilis. In general, family 11 Xylanases were the preferred synergistic partners with feruloyl esterases for the release of ferulic acid, while family 10 Xylanases were preferred for the liberation of diferulic acid, with only the 5,5′ form being released by the action of AnFaeA alone. This suggests that ferulic acid may be located in regions of low substitution on arabinoxylans while the 5,5′ diferulate moiety is located in more branched regions of the xylan chain.
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Interactions defining the specificity between fungal Xylanases and the Xylanase-inhibiting protein XIP-I from wheat.
The Biochemical journal, 2002Co-Authors: Ruth Flatman, Richard K. Hughes, Nathalie Juge, Paloma Manzanares, W Russell Mclauchlan, Caroline Furniss, Jean-guy Berrin, John E Ladbury, Ronan O'brien, Gary WilliamsonAbstract:We previously reported on the Xylanase-inhibiting protein I (XIP-I) from wheat [McLauchlan, Garcia-Conesa, Williamson, Roza, Ravestein and Maat (1999), Biochem. J. 338, 441-446]. In the present study, we show that XIP-I inhibits family-10 and -11 fungal Xylanases. The K(i) values for fungal Xylanases ranged from 3.4 to 610 nM, but bacterial family-10 and -11 Xylanases were not inhibited. Unlike many glycosidase inhibitors, XIP-I was not a slow-binding inhibitor of the Aspergillus niger Xylanase. Isothermal titration calorimetry of the XIP-I-A. niger Xylanase complex showed the formation of a stoichiometric (1:1) complex with a heat capacity change of -1.38 kJ x mol(-1) x K(-1), leading to a predicted buried surface area of approx. 2200+/-500 A(2) at the complex interface. For this complex with A. niger Xylanase (K(i)=320 nM at pH 5.5), titration curves indicated that an observable interaction occurred at pH 4-7, and this was consistent with the pH profile of inhibition of activity. In contrast, the stronger complex between A. nidulans Xylanase and XIP-I (K(i)=9 nM) led to an observable interaction across the entire pH range tested (3-9). Using surface plasmon resonance, we show that the differences in the binding affinity of XIP-I for A. niger and A. nidulans Xylanase are due to a 200-fold lower dissociation rate k(off) for the latter, with only a small difference in association rate k(on).
T Satyanarayana - One of the best experts on this subject based on the ideXlab platform.
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cloning expression and applicability of thermo alkali stable Xylanase of geobacillus thermoleovorans in generating xylooligosaccharides from agro residues
Bioresource Technology, 2012Co-Authors: Digvijay Verma, T SatyanarayanaAbstract:Abstract A Xylanase gene (xyl-gt) of 1.224 kbp was cloned from the extremely thermophilic bacterium Geobacillus thermoleovorans that encodes a protein containing 408 amino acid residues. Eight conserved regions (signature sequences) of GH family 10 Xylanases have been found in the Xylanase. When the Xylanase gene was cloned and expressed in Escherichia coli BL21 (DE3), the recombinant strain produced Xylanase titer of 270 U mg−1 which is 27-fold higher than the wild strain. It is optimally active at 80 °C and pH 8.5 with a high thermostability over broad range of pH (6–12) and temperature (40–100 °C). The end products of the hydrolysis of birch wood xylan and agro-residues included xylobiose, xylotriose, xylotetraose and xylopentaose. The Xylanase of G. thermoleovorans is one of the rare Xylanases that exhibits thermo-alkali-stability, and thus, it is a suitable candidate for pre-bleaching of paper pulps and generating xylooligosaccharides from agro-residues for use as prebiotics.
Paloma Manzanares - One of the best experts on this subject based on the ideXlab platform.
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second generation ethanol production from steam exploded barley straw by kluyveromyces marxianus cect 10875
Fuel, 2011Co-Authors: M P Garciaaparicio, Paloma Manzanares, J M Oliva, Mercedes Ballesteros, Ignacio Ballesteros, Alberto Gonzalez, M J NegroAbstract:Abstract Barley straw is nowadays being considered a potential lignocellulosic raw material for fuel-ethanol production as an alternative to starch- or sugar-containing feedstock. In this work, several configuration strategies for ethanol production from steam-exploded barley straw by Kluyveromyces marxianus CECT 10875 have been studied with the aim of obtaining higher ethanol concentrations. Different substrate loading (2–15%, w/v) were studied during enzymatic hydrolysis. The Xylanase contribution on glucose production and glucan conversion at different substrate loading was also investigated. In addition, three different process configurations, separate hydrolysis and fermentation, simultaneous saccharification and fermentation and presaccharification and simultaneous saccharification, were compared at different water insoluble solids concentration (5%, 10% and 15%). The influence of Xylanase addition on the ethanol yield was studied as well. Results show that endo-Xylanases improved glucan conversion and ethanol yield compared with a standard enzymatic mixture, markedly at low substrate concentration. The positive effect of added Xylanase was most evident at early stages of enzymatic hydrolysis. Regarding process configurations for the period of 72 h, SSF with endo-Xylanases provided the best ethanol yield, nearly 70%, for 10% WIS. Nonetheless, the higher ethanol concentration, 29.4 g/l, was obtained at 15% WIS.
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the dual nature of the wheat Xylanase protein inhibitor xip i structural basis for the inhibition of family 10 and family 11 Xylanases
Journal of Biological Chemistry, 2004Co-Authors: Francoise Payan, Anne Durand, Philippe Leone, S Porciero, Caroline S M Furniss, T Tahir, Gary Williamson, Paloma Manzanares, Harry J Gilbert, Nathalie JugeAbstract:Abstract The Xylanase inhibitor protein I (XIP-I) from wheat Triticum aestivum is the prototype of a novel class of cereal protein inhibitors that inhibit fungal Xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). The crystal structures of XIP-I in complex with Aspergillus nidulans (GH10) and Penicillium funiculosum (GH11) Xylanases have been solved at 1.7 and 2.5 A resolution, respectively. The inhibition strategy is novel because XIP-I possesses two independent enzyme-binding sites, allowing binding to two glycoside hydrolases that display a different fold. Inhibition of the GH11 Xylanase is mediated by the insertion of an XIP-I Π-shaped loop (Lα4β5) into the enzyme active site, whereas residues in the helix α7 of XIP-I, pointing into the four central active site subsites, are mainly responsible for the reversible inactivation of GH10 Xylanases. The XIP-I strategy for inhibition of Xylanases involves substrate-mimetic contacts and interactions occluding the active site. The structural determinants of XIP-I specificity demonstrate that the inhibitor is able to interact with GH10 and GH11 Xylanases of both fungal and bacterial origin. The biological role of the Xylanase inhibitors is discussed in light of the present structural data.
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Interactions defining the specificity between fungal Xylanases and the Xylanase-inhibiting protein XIP-I from wheat.
The Biochemical journal, 2002Co-Authors: Ruth Flatman, Richard K. Hughes, Nathalie Juge, Paloma Manzanares, W Russell Mclauchlan, Caroline Furniss, Jean-guy Berrin, John E Ladbury, Ronan O'brien, Gary WilliamsonAbstract:We previously reported on the Xylanase-inhibiting protein I (XIP-I) from wheat [McLauchlan, Garcia-Conesa, Williamson, Roza, Ravestein and Maat (1999), Biochem. J. 338, 441-446]. In the present study, we show that XIP-I inhibits family-10 and -11 fungal Xylanases. The K(i) values for fungal Xylanases ranged from 3.4 to 610 nM, but bacterial family-10 and -11 Xylanases were not inhibited. Unlike many glycosidase inhibitors, XIP-I was not a slow-binding inhibitor of the Aspergillus niger Xylanase. Isothermal titration calorimetry of the XIP-I-A. niger Xylanase complex showed the formation of a stoichiometric (1:1) complex with a heat capacity change of -1.38 kJ x mol(-1) x K(-1), leading to a predicted buried surface area of approx. 2200+/-500 A(2) at the complex interface. For this complex with A. niger Xylanase (K(i)=320 nM at pH 5.5), titration curves indicated that an observable interaction occurred at pH 4-7, and this was consistent with the pH profile of inhibition of activity. In contrast, the stronger complex between A. nidulans Xylanase and XIP-I (K(i)=9 nM) led to an observable interaction across the entire pH range tested (3-9). Using surface plasmon resonance, we show that the differences in the binding affinity of XIP-I for A. niger and A. nidulans Xylanase are due to a 200-fold lower dissociation rate k(off) for the latter, with only a small difference in association rate k(on).
Maria De Lourdes Teixeira De Moraes Polizeli - One of the best experts on this subject based on the ideXlab platform.
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Xylanases from aspergillus niger aspergillus niveus and aspergillus ochraceus produced under solid state fermentation and their application in cellulose pulp bleaching
Bioprocess and Biosystems Engineering, 2009Co-Authors: Jorge Henrique Almeida Betini, Simone C Peixotonogueira, Michele Michelin, Joao Atilio Jorge, Hector Francisco Terenzi, Maria De Lourdes Teixeira De Moraes PolizeliAbstract:This study describes the production of Xylanases from Aspergillus niveus, A. niger, and A. ochraceus under solid-state fermentation using agro-industrial residues as substrates. Enzyme production was improved using a mixture of wheat bran and yeast extract or peptone. When a mixture of corncob and wheat bran was used, Xylanase production from A. niger and A. ochraceus increased by 18%. All cultures were incubated at 30 °C at 70–80% relative humidity for 96 h. For biobleaching assays, 10 or 35 U of Xylanase/g dry cellulose pulp were incubated at pH 5.5 for 1 or 2 h, at 55 °C. The delignification efficiency was 20%, the brightness (percentage of ISO) increased two to three points and the viscosity was maintained confirming the absence of cellulolytic activity. These results indicated that the use of Xylanases could help to reduce the amount of chlorine compounds used in cellulose pulp treatment.
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production of Xylanase by aspergilli using alternative carbon sources application of the crude extract on cellulose pulp biobleaching
Journal of Industrial Microbiology & Biotechnology, 2009Co-Authors: Simone C Peixotonogueira, Michele Michelin, Jorge Henrique Almeida Betini, Joao Atilio Jorge, Hector Francisco Terenzi, Maria De Lourdes Teixeira De Moraes PolizeliAbstract:The ability of xylanolytic enzymes produced by Aspergillus fumigatus RP04 and Aspergillus niveus RP05 to promote the biobleaching of cellulose pulp was investigated. Both fungi grew for 4–5 days in liquid medium at 40°C, under static conditions. Xylanase production was tested using different carbon sources, including some types of xylans. A. fumigatus produced high levels of Xylanase on agricultural residues (corncob or wheat bran), whereas A. niveus produced more Xylanase on birchwood xylan. The optimum temperature of the Xylanases from A. fumigatus and A. niveus was around 60–70°C. The enzymes were stable for 30 min at 60°C, maintaining 95–98% of the initial activity. After 1 h at this temperature, the Xylanase from A. niveus still retained 85% of initial activity, while the Xylanase from A. fumigatus was only 40% active. The pH optimum of the Xylanases was acidic (4.5–5.5). The pH stability for the Xylanase from A. fumigatus was higher at pH 6.0–8.0, while the enzyme from A. niveus was more stable at pH 4.5–6.5. Crude enzymatic extracts were used to clarify cellulose pulp and the best result was obtained with the A. niveus preparation, showing kappa efficiency around 39.6% as compared to only 11.7% for that of A. fumigatus.
Ghulam Mohiuddin - One of the best experts on this subject based on the ideXlab platform.
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production and characterization of thermostable Xylanases by thermomyces lanuginosus and thermoascus aurantiacus grown on lignocelluloses
Enzyme and Microbial Technology, 1994Co-Authors: Mustafa Alam, Isidore Gomes, Ghulam MohiuddinAbstract:Thermomyces lanuginosus and Thermoascus aurantiacus isolated from self-heated jute fiber stalk were studied for Xylanase production using various lignocelluloses under solid-state fermentation. Both organisms performed creditably well with unsupplemented wheat bran at 55°C. T. lanuginosus produced cellulase-free Xylanase, whereas T. aurantiacus produced a small amount of cellulase in addition. Xylan (0.7%) also induced Xylanase production in T. lanuginosus, leading to a 28.0% increase. The effect of initial moisture level was optimized for the fungi. T. lanuginosus and T. aurantiacus performed best at 80 and 50% initial moisture, respectively. Characterization of the enzymes reveals that Xylanases from T. lanuginosus and T. aurantiacus were most active at 70°C, but at pH 6.0 and 5.0, respectively. Both Xylanases displayed remarkable pH (5.0 to 11.0) and thermal stabilities by retaining most of their activities even after having been subjected to temperatures much higher than their optimal. Furthermore, they remained active under prolonged storage, having no loss of activity after 1 month of storage at 4°C and retaining up to about 90% after 10 days at 55°C. Xylanase from T. lanuginosus was better and produced a softer and mechanically stronger final product than that from T. aurantiacus when both were applied to low-quality jute fiber. The findings in this study have great implications for the future applications of Xylanase.
