The GH51 α-l-arabinofuranosidase from Paenibacillus sp. THS1 is multifunctional, hydrolyzing main-chain and side-chain glycosidic bonds in heteroxylans.

Background: Conceptually, multi functional enzymes are attractive because in the case of complex polymer hydrolysis having two or more activities defined by a single enzyme offers the possibility of synergy and reduced enzyme cocktail complexity. Nevertheless, multi functional enzymes are quite rare and are generally multi domain assemblies with each activity being defined by a separate protein module. However, a recent report described a GH51 arabinofuranosidase from Alicyclobacillus sp. A4 that displays both α l arabinofuranosidase and β d xylanase activities, which are defined by a single active site. Following on from this, we describe in detail another multi functional GH51 arabinofuranosidase and discuss the molecular basis of multifunctionality. Results: THSAbf is a GH51 α l arabinofuranosidase. Characterization revealed that THSAbf is active up to 75 °C, stable at 60 °C and active over a broad pH range (4–7). THSAbf preferentially releases para nitrophenyl from the l arabino furanoside ( k cat / K M = 1050 s − 1 mM − 1 ) and to some extent from d galactofuranoside and d xyloside. THSAbf is active on 4 O methylglucuronoxylans from birch and beechwood (10.8 and 14.4 U mg − 1 , respectively) and on sugar beet branched and linear arabinans (1.1 ± 0.24 and 1.8 ± 0.1 U mg − 1 ). Further investigation revealed that like the Alicyclo - bacillus sp. A4 α l arabinofuranosidase, THSAbf also displays endo xylanase activity, cleaving β 1,4 bonds in heteroxy lans. The optimum pH for THASAbf activity is substrate dependent, but ablation of the catalytic nucleophile caused a general loss of activity, indicating the involvement of a single active center. Combining the α l arabinofuranosidase with a GH11 endoxylanase did not procure synergy. The molecular modeling of THSAbf revealed a wide active site cleft and clues to explain multi functionality

A substrate for the detection of broad specificity alpha-L-arabinofuranosidases with indirect release of a chromogenic group

The synthesis of a compound containing a 4-nitrocatechol bound to two vicinal alpha-L-arabinofuranosyl moieties through a linker arm was achieved using a sulfate protecting group to facilitate selective alkylation of one aromatic hydroxyl. Several alpha-L-arabinofuranosidases displaying different selectivities were tested and a simple microtiter plate-based assay was developed. The observed resistance of the compound to alpha-L-arabinofuranosidase-mediated hydrolysis makes it suitable for the identification of enzymes that are able to accommodate bis-arabinofuranosylated moieties. (C) 2013 Elsevier Ltd. All rights reserved

Procédé de dégradation de produits plastiques

The present invention relates to processes for degrading plastic products and the uses thereof. The processes of the invention particularly comprise a step of amorphizing a plastic product prior to a step of depolymerization. The processes of the invention are particularly useful for degrading a plastic product comprising polyethylene terephthalate and/or polylactic acid. The invention also relates to a method of producing monomers and/or oligomers from a plastic product comprising at least one polyester, particularly polyethylene terephthalate and/or polylactic acid, comprising submitting the plastic product both to an amorphization step and to a depolymerization step.La présente invention concerne des procédés de dégradation de produits plastiques et leurs utilisations. Les procédés de l'invention comprennent en particulier une étape d'amorphisation d'un produit plastique avant une étape de dépolymérisation. Les procédés de l'invention sont particulièrement utiles pour dégrader un produit plastique comprenant du polytéréphtalate d'éthylène et/ou de l'acide polylactique. L'invention concerne également un procédé de production de monomères et/ou d'oligomères à partir d'un produit plastique comprenant au moins un polyester, en particulier du polytéréphtalate d'éthylène et/ou de l'acide polylactique, consistant à soumettre le produit plastique à la fois à une étape d'amorphisation et à une étape de dépolymérisation

Esterases and uses thereof

The present invention relates to novel esterase, more particularly to esterase variants having improved activity compared to the esterase of SEQ ID No 1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate

Novel esterases and uses thereof

The present invention relates to novel esterase, more particularly to esterase variants having improved thermostability compared to the esterase of SEQ ID No 1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate

NOUVELLES ESTÉRASES ET UTILISATIONS ASSOCIÉES

The present invention relates to novel esterase, more particularly to esterase variants having improved activity compared to the esterase of SEQ ID N° 1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate.L'invention concerne une nouvelle estérase, plus particulièrement des variants d'estérase présentant une activité améliorée par rapport à l'estérase de SEQ ID N° 1 et leurs utilisations dans la dégradation d'un matériau contenant du polyester, tel que des produits plastiques. Les estérases selon l'invention sont particulièrement adaptées pour dégrader du téréphtalate de polyéthylène et un matériau contenant du téréphtalate de polyéthylène

NOUVELLES ESTÉRASES ET LEURS UTILISATIONS

The present invention relates to novel esterase, more particularly to esterase variants having improved thermostability compared to the esterase of SEQ ID N°1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate.La présente invention concerne une nouvelle estérase, plus particulièrement des variantes d'estérase ayant une meilleure thermostabilité par rapport à l'estérase de SEQ ID N°1, et les utilisations de l'estérase pour dégrader les matériaux contenant du polyester, par exemple les produits en plastique. Les estérases selon l'invention sont particulièrement appropriées pour dégrader le polyéthylène téréphtalate, et les matériaux contenant du polyéthylène téréphtalate

A H-1 NMR study of the specificity of alpha-L-arabinofuranosidases on natural and unnatural substrates

BACKGROUND: The detailed characterization of arabinoxylan-active enzymes, such as double-substituted xylan arabinofuranosidase activity, is still a challenging topic. Ad hoc chromogenic substrates are useful tools and can reveal subtle differences in enzymatic behavior. In this study, enzyme selectivity on natural substrates has been compared with enzyme selectivity towards aryl-glycosides. This has proven to be a suitable approach to understand how artificial substrates can be used to characterize arabinoxylan-active α-l-arabinofuranosidases (Abfs). METHODS: Real-time NMR using a range of artificial chromogenic, synthetic pseudo-natural and natural substrates was employed to determine the hydrolytic abilities and specificity of different Abfs. RESULTS: The way in which synthetic di-arabinofuranosylated substrates are hydrolyzed by Abfs mirrors the behavior of enzymes on natural arabinoxylo-oligosaccharide (AXOS). Family GH43 Abfs that are strictly specific for mono-substituted d-xylosyl moieties (AXH-m) do not hydrolyze synthetic di-arabinofuranosylated substrates, while those specific for di-substituted moieties (AXH-d) remove a single l-arabinofuranosyl (l-Araf) group. GH51 Abfs, which are supposedly AXH-m enzymes, can release l-Araf from disubstituted d-xylosyl moieties, when these are non-reducing terminal groups. CONCLUSIONS AND GENERAL SIGNIFICANCE: The present study reveals that although the activity of Abfs on artificial substrates can be quite different from that displayed on natural substrates, enzyme specificity is well conserved. This implies that carefully chosen artificial substrates bearing di-arabinofuranosyl d-xylosyl moieties are convenient tools to probe selectivity in new Abfs. Moreover, this study has further clarified the relative promiscuity of GH51 Abfs, which can apparently hydrolyze terminal disubstitutions in AXOS, albeit less efficiently than mono-substituted motifs.publisher: Elsevier articletitle: A 1H NMR study of the specificity of α-l-arabinofuranosidases on natural and unnatural substrates journaltitle: Biochimica et Biophysica Acta (BBA) - General Subjects articlelink: http://dx.doi.org/10.1016/j.bbagen.2014.07.001 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

A Versatile and Colorful Screening Tool for the Identification of Arabinofuranose-Acting Enzymes

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