Targeted molecular engineering of a family 11 endoxylanase to decrease its sensitivity towards Triticum aestivum endoxylanase inhibitor types.

The Bacillus subtilis endoxylanase XynA (BSXY) is frequently used to improve the functionality of arabinoxylan-containing material in cereal based industries. The presence of endogenous Triticum aestivum xylanase inhibitors (TAXI-I and TAXI-II) in wheat is a real concern as they have a direct negative impact on the efficiency of this enzyme. Here, we used the recently determined structure of the complex between TAXI-I and an endoxylanase of Aspergillus niger to develop inhibitor-insensitive BSXY variants by site-directed mutagenesis of strategically chosen amino acids.

Recombinant expression and characterization of XynD from Bacillus subtilis subsp. subtilis ATCC 6051: a GH 43 arabinoxylan arabinofuranohydrolase.

The complete genome sequence of Bacillus subtilis reveals that sequences encoding several hemicellulases are co-localised with a gene (xynD) encoding a putative family 43 glycoside hydrolase that has not yet been characterised. In this work, xynD has been isolated from genomic DNA of B. subtilis subsp.

Engineering molecular recognition of endoxylanase enzymes and their inhibitors through phage display.

Specific binding of interacting proteins generally depends on a limited set of amino acid residues located at the contact interface. We have applied a phage-display-based screening method to simultaneously evaluate the role of multiple residues of endo-beta-1,4-xylanase enzymes in conferring binding specificity towards two different endoxylanase inhibitors. Seven residues of the two beta-strand 'thumb' region of Trichoderma longibrachiatum endo-beta-1,4-xylanase XynII were targeted for randomization.

Unprocessed barley aleurone endo-beta-1,4-xylanase X-I is an active enzyme.

Endo-beta-1,4-xylanase X-I is a major hydrolase produced by the aleurone tissue of germinating barley grain. It was previously reported that this cytosolic enzyme is synthesized as an inactive precursor which is proteolytically processed to active forms upon its programmed cell death dependent release. We here demonstrate, however, that the precursor form of X-I is an active enzyme.

Variability in the structure of rye flour alkali-extractable arabinoxylans.

The variability in rye flour alkali-extractable arabinoxylan (AE-AX) structures was examined by extensive fractionation and enzymic degradation studies. AX were isolated from destarched rye water-unextractables by sequential extraction with saturated barium hydroxide solution, water, 1.0 M sodium hydroxide, and water.

TLXI, a novel type of xylanase inhibitor from wheat (Triticum aestivum) belonging to the thaumatin family.

Wheat (Triticum aestivum) contains a previously unknown type of xylanase (EC 3.2.1.

Rnd family genes are differentially regulated by 3,4-methylenedioxymethamphetamine and cocaine acute treatment in mice brain.

Drugs of abuse induce alterations in cytoskeletal and cytoskeleton associated genes in several brain areas. We have previously shown that acute MDMA regulates the mRNA level of Rnd3, a Rho GTPase involved in actin cytoskeleton regulation, in mice striatum. In this study we investigated the effects of single administration of cocaine, another psychostimulant with a slightly different mechanism of action, on the mRNA levels of the three members of the Rnd genes family (Rnd1, Rnd2 and Rnd3).

Insight into the distribution of arabinoxylans, endoxylanases, and endoxylanase inhibitors in industrial wheat roller mill streams.

To gain insight into the distribution of arabinoxylans (AX), endoxylanases, and endoxylanase inhibitors in industrial wheat roller milling, all streams, that is, 54 flour fractions, 4 bran fractions, and the germ, were analyzed for ash, starch, and protein contents, alpha-amylase activity levels, total (TOT-AX) and water-extractable arabinoxylan (WE-AX) contents, endoxylanase activity levels, and endoxylanase inhibitor (TAXI and XIP) contents. In general, bran fractions were significantly richer in TOT-AX and WE-AX contents, endoxylanase activity levels, and endoxylanase inhibitor contents than germ and, even more so, than flour fractions. In the 54 different flour fractions, minimal and maximal values for TOT-AX and WE-AX contents differed by ca.

Sensitization to the conditioned rewarding effects of morphine modulates gene expression in rat hippocampus.

Opiates addiction is characterized by its long-term persistence. In order to study the enduring changes in long-term memory in hippocampus, a pivotal region for this process, we used suppression subtractive hybridization to compare hippocampal gene expression in morphine and saline-treated rats. Animals were subjected to an extended place preference paradigm consisting of four conditioning phases.

Non-digestible oligosaccharides with prebiotic properties.

The search for functional foods or functional food ingredients, i.e. foods or food ingredients that can enhance health, is beyond any doubt one of the leading trends in today's food industry.

Wheat-kernel-associated endoxylanases consist of a majority of microbial and a minority of wheat endogenous endoxylanases.

The endoxylanases associated with wheat kernels consist of wheat endogenous endoxylanases on one hand and kernel-associated microbial endoxylanases on the other hand. Assessment of their presence, based on analysis of their enzymic activity, can be expected to be hampered by the presence in wheat of high levels of endogenous endoxylanase inhibitors, which are able to inhibit the wheat-kernel-associated microbial endoxylanases. On the basis of preliminary experiments aimed at clarifying the distribution of the wheat-associated endoxylanases, a method to estimate total endoxylanase activities in wheat kernels was developed.

Frequency and fitness cost of resistance to Bacillus thuringiensis in Chrysomela tremulae (Coleoptera: Chrysomelidae).

The "high dose-refuge" (HDR) strategy is commonly recommended and currently used for delaying or preventing pest adaptation to transgenic plants producing Bacillus thuringiensis (Bt) toxins. The efficiency of this strategy depends, among other factors, on the initial frequency of Bt resistance alleles and on the fitness costs associated with these alleles. Two years ago, an allele conferring resistance to Bt poplar was detected in a French population of the poplar pest Chrysomela tremulae F.

Regulation of genes involved in dopamine transporter modulation by acute cocaine in rat striatum.

It is well established that acute administration of psychostimulants alters dopamine transport. However, the exact mechanism of this modulation is still unknown. In this study we examined the mRNA levels of several proteins involved in the various proposed processes following cocaine administration.

His374 of wheat endoxylanase inhibitor TAXI-I stabilizes complex formation with glycoside hydrolase family 11 endoxylanases.

Wheat endoxylanase inhibitor TAXI-I inhibits microbial glycoside hydrolase family 11 endoxylanases. Crystallographic data of an Aspergillus niger endoxylanase-TAXI-I complex showed His374 of TAXI-I to be a key residue in endoxylanase inhibition. Its role in enzyme-inhibitor interaction was further investigated by site-directed mutagenesis of His374 into alanine, glutamine or lysine.

Evidence for the involvement of arabinoxylan and xylanases in refrigerated dough syruping.

The relationship between syruping in refrigerated doughs upon prolonged storage and different aspects of arabinoxylan (AX) hydrolysis was investigated using Triticum aestivum xylanase inhibitor (TAXI) and different xylanases in the dough formula. Dough characteristics were evaluated with strong emphasis on the AX population and its fate as a function of storage time. Selective reduction of part of the flour endogenous xylanase activity in dough by added TAXI reduced dough syruping after 12 and 20 days of storage by 50%, providing straightforward evidence for the involvement of xylanases and, thus, AX in the syruping phenomenon.

Enzymic degradability of hull-less barley flour alkali-solubilized arabinoxylan fractions by endoxylanases.

The impacts of the arabinose to xylose (A/X) ratio of arabinoxylans (AX) and the endoxylanase substrate specificity on the enzymic degradability of hull-less barley flour AX by endoxylanases were studied by using alkali-solubilized AX (AS-AX) fractions with different A/X ratio, on the one hand, and glycoside hydrolase family 10 and 11 endoxylanases of Aspergillus aculeatus (XAA) and Bacillus subtilis (XBS), respectively, on the other hand. AS-AX were obtained by saturated barium hydroxide treatment of hull-less barley flour water-unextractable AX. Fractionation of AS-AX by stepwise ethanol precipitation resulted in structurally different hull-less barley flour AS-AX fractions.

Molecular identification of wheat endoxylanase inhibitor TAXI-II and the determinants of its inhibition specificity.

Wheat grains contain Triticum aestivum xylanase inhibitor (TAXI) proteins which inhibit microbial xylanases, some of which are used in cereal based food industries. These inhibitors may play a role in plant defence. Among the TAXI isoforms described so far, TAXI-II displays a deviating inhibition specificity pattern.

Clear cell 'sugar' tumor (PEComa) of the skin: a case report.

The so-called perivascular epithelioid cell neoplasm (PEComa) family includes angiomyolipoma, clear cell 'sugar' tumor (CCST), lymphangioleiomyomatosis, and clear cell myomelanocytic tumor (CCMMT). These rare tumors are characterized by the co-expression of melanocytic and muscle markers. They have been recognized in an increasing number of sites but currently only one case of PEComa, of the CCMMT subtype, has been reported in the skin in abstract form.

Purification and characterization of a XIP-type endoxylanase inhibitor from rice (Oryza sativa).

A rice XIP-type inhibitor was purified by affinity chromatography with an immobilized Aspergillus aculeatus family 10 endoxylanase. Rice XIP is a monomeric protein, with a molecular mass of ca. 32 kDa and a pI of ca.

Endoxylanase substrate selectivity determines degradation of wheat water-extractable and water-unextractable arabinoxylan.

The relative activity of an endoxylanase towards water-unextractable (WU-AX) and water-extractable arabinoxylan (WE-AX) substrates, referred to as endoxylanase substrate selectivity, impacts the enzyme functionality in cereal-based biotechnological processes such as bread-making and gluten starch separation. A set of six endoxylanases representing a range of substrate selectivities as determined by a screening method using chromophoric substrates [Anal. Biochem.

Metacognitive development of deaf children: lessons from the appearance-reality and false belief tasks.

'Theory of mind' development is now an important research field in deaf studies. Past research with the classic false belief task has consistently reported a delay in theory of mind development in deaf children born of hearing parents, while performance of second-generation deaf children is more problematic with some contradictory results. The present paper is aimed at testing the metacognitive abilities of deaf children on two tasks: the appearance-reality paradigm designed by Flavell, Flavell and Green (1983) and the classic false belief inference task (Wimmer & Perner, 1983; Hogrefe, Wimmer & Perner, 1986).

Water-extractable and water-unextractable arabinoxylans affect gluten agglomeration behavior during wheat flour gluten-starch separation.

Water-extractable arabinoxylan (WE-AX) of variable molecular weight (MW) and water-unextractable arabinoxylan (WU-AX) were added to wheat flour to study their effect on gluten agglomeration in a dough and batter gluten-starch separation process with recovery of gluten from the batter with a set of vibrating sieves (400, 250, and 125 microm). Low MW WE-AX had almost no impact on the distribution of the gluten on the different sieves. High MW WE-AX decreased yields of the largest (400 microm sieve) gluten aggregates, more than their medium MW counterparts, indicating the importance of AX MW for their effect on gluten interactions.

The impact of sign language on the cognitive development of deaf children: the case of theories of mind.

The ability to attribute false beliefs (i.e., demonstrate theory of mind) by 155 deaf children between 5 and 8 years of age was compared to that of 39 hearing children ages 4 to 6.