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Pentari C, Zerva A, Kosinas C, Karampa P, Puchart V, Dimarogona M, Topakas E. The role of CE16 exo-deacetylases in hemicellulolytic enzyme mixtures revealed by the biochemical and structural study of the novel TtCE16B esterase. Carbohydr Polym 2024; 327:121667. [PMID: 38171682 DOI: 10.1016/j.carbpol.2023.121667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/03/2023] [Accepted: 12/04/2023] [Indexed: 01/05/2024]
Abstract
Acetyl esterases belonging to the carbohydrate esterase family 16 (CE16) is a growing group of enzymes, with exceptional diversity regarding substrate specificity and regioselectivity. However, further insight into the CE16 specificity is required for their efficient biotechnological exploitation. In this work, exo-deacetylase TtCE16B from Thermothelomyces thermophila was heterologously expressed and biochemically characterized. The esterase targets positions O-3 and O-4 of singly and doubly acetylated non-reducing-end xylopyranosyl residues, provided the presence of a free vicinal hydroxyl group at position O-4 and O-3, respectively. Crystal structure of TtCE16B, the first representative among the CE16 enzymes, in apo- and product-bound form, allowed the identification of residues forming the catalytic triad and oxyanion hole, as well as the structural elements related to the enzyme preference for oligomers. The role of TtCE16B in hemicellulose degradation was investigated on acetylated xylan from birchwood and pre-treated beechwood biomass. TtCE16B exhibited complementary activity to commercially available OCE6 acetylxylan esterase. Moreover, it showed synergistic effects with SrXyl43 β-xylosidase. Overall, supplementation of xylan-targeting enzymatic mixtures with both TtCE16B and OCE6 esterases led to a 3-fold or 4-fold increase in xylose release, when using TmXyn10 and TtXyn30A xylanases respectively.
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Affiliation(s)
- Christina Pentari
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece
| | - Anastasia Zerva
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece; Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, 11855 Athens, Greece
| | - Christos Kosinas
- Laboratory of Structural Biology and Biotechnology, Department of Chemical Engineering, University of Patras, Patras, Greece
| | - Panagiota Karampa
- Laboratory of Structural Biology and Biotechnology, Department of Chemical Engineering, University of Patras, Patras, Greece
| | - Vladimír Puchart
- Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38 Bratislava, Slovak Republic
| | - Maria Dimarogona
- Laboratory of Structural Biology and Biotechnology, Department of Chemical Engineering, University of Patras, Patras, Greece.
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, Athens, Greece.
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2
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Microbial xylanolytic carbohydrate esterases. Essays Biochem 2022; 67:479-491. [PMID: 36468678 DOI: 10.1042/ebc20220129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/04/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022]
Abstract
Abstract
This article reviews microbial esterases participating in the degradation of the major plant hemicellulose, xylan. The main chain of this polysaccharide built of β-1,4-glycosidically linked xylopyranosyl residues is substituted by other sugars and also partially acetylated. Besides esters of acetic acid, there are two other types of ester linkages in plant xylans. L-Arabinofuranosyl side chains form esters with phenolic acids, predominantly with ferulic acid. The dimerization of ferulic acid residues leads to cross-links connecting the hemicellulose molecules. Ferulic acid cross-links were shown to serve as covalent linkage between lignin and hemicellulose. Another cross-linking between lignin and hemicellulose is provided by esters between the xylan side residues of glucuronic or 4-O-methyl-D-glucurononic acid and lignin alcohols. Regardless of the cross-linking, the side residues prevent xylan main chains from association that leads to crystallization similar to that of cellulose. Simultaneously, xylan decorations hamper the action of enzymes acting on the main chain. The enzymatic breakdown of plant xylan, therefore, requires a concerted action of glycanases attacking the main chain and enzymes catalyzing debranching, called accessory xylanolytic enzymes including xylanolytic esterases. While acetylxylan esterases and feruloyl esterases participate directly in xylan degradation, glucuronoyl esterases catalyze its separation from lignin. The current state of knowledge of diversity, classification and structure–function relationship of these three types of xylanolytic carbohydrate esterases is discussed with emphasis on important aspects of their future research relevant to their industrial applications.
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3
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Carbohydrate esterase family 16 contains fungal hemicellulose acetyl esterases (HAEs) with varying specificity. N Biotechnol 2022; 70:28-38. [DOI: 10.1016/j.nbt.2022.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 04/05/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022]
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4
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Industrially Important Genes from Trichoderma. Fungal Biol 2022. [DOI: 10.1007/978-3-030-91650-3_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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5
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Li X, Dilokpimol A, Kabel MA, de Vries RP. Fungal xylanolytic enzymes: Diversity and applications. BIORESOURCE TECHNOLOGY 2022; 344:126290. [PMID: 34748977 DOI: 10.1016/j.biortech.2021.126290] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 10/29/2021] [Accepted: 11/01/2021] [Indexed: 05/26/2023]
Abstract
As important polysaccharide degraders in nature, fungi can diversify their extensive set of carbohydrate-active enzymes to survive in ecological habitats of various composition. Among these enzymes, xylanolytic ones can efficiently and sustainably degrade xylans into (fermentable) monosaccharides to produce valuable chemicals or fuels from, for example relevant for upgrading agro-food industrial side streams. Moreover, xylanolytic enzymes are being used in various industrial applications beyond biomass saccharification, e.g. food, animal feed, biofuel, pulp and paper. As a reference for researchers working in related areas, this review summarized the current knowledge on substrate specificity of xylanolytic enzymes from different families of the Carbohydrate-Active enZyme database. Additionally, the diversity of enzyme sets in fungi were discussed by comparing the number of genes encoding xylanolytic enzymes in selected fungal genomes. Finally, to support bio-economy, the current applications of fungal xylanolytic enzymes in industry were reviewed.
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Affiliation(s)
- Xinxin Li
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Mirjam A Kabel
- Laboratory of Food Chemistry, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands.
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6
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Kato T, Shiono Y, Koseki T. Identification and characterization of an acetyl xylan esterase from Aspergillus oryzae. J Biosci Bioeng 2021; 132:337-342. [PMID: 34376338 DOI: 10.1016/j.jbiosc.2021.06.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/28/2022]
Abstract
In this study, we report the identification and characterization of an acetyl xylan esterase, designated as AoAXEC, which was previously annotated as a hypothetical protein encoded by AO090023000158 in the Aspergillus oryzae genomic database. Based on its amino acid sequence, a low sequence identity to known acetyl xylan esterases was observed in the sequence of characterized acetyl xylan esterase. The gene fused with α-factor signal sequence of Saccharomyces cerevisiae instead of the native signal sequence was cloned into a vector, pPICZαC, and expressed successfully in Pichia pastoris as an active extracellular protein. The purified recombinant protein had pH and temperature optima of 7.0 and 50 °C, respectively, and was stable up to 50 °C. The optimal substrate for hydrolysis by the purified recombinant AoAXEC, among a panel of α-naphthyl esters (C2-C16), was α-naphthyl propionate (C3), with an activity of 0.35 ± 0.006 units/mg protein. No significant difference of the Km value was observed between C3 (2.3 ± 0.7 mM) and C2 (1.9 ± 0.4 mM). In contrast, kcat value for C3 (18 ± 3.9 s-1) was higher compared to C2 (4.5 ± 0.7 s-1). The purified recombinant enzyme displayed a low activity toward acyl chain substrates containing eight or more carbon atoms. Recombinant AoAXEC catalyzed the release of acetic acid from wheat arabinoxylan. However, no activity was detected on methyl esters of ferulic, p-coumaric, caffeic, or sinapic acids. Additionally, the liberation of phenolic acids, such as ferulic acid, from wheat arabinoxylan was not exhibited by the recombinant protein.
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Affiliation(s)
- Tomoe Kato
- Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan
| | - Yoshihito Shiono
- Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan
| | - Takuya Koseki
- Faculty of Agriculture, Yamagata University, 1-23 Wakaba-machi, Tsuruoka, Yamagata 997-8555, Japan.
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Harvey DJ. ANALYSIS OF CARBOHYDRATES AND GLYCOCONJUGATES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION MASS SPECTROMETRY: AN UPDATE FOR 2015-2016. MASS SPECTROMETRY REVIEWS 2021; 40:408-565. [PMID: 33725404 DOI: 10.1002/mas.21651] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/24/2020] [Indexed: 06/12/2023]
Abstract
This review is the ninth update of the original article published in 1999 on the application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2016. Also included are papers that describe methods appropriate to analysis by MALDI, such as sample preparation techniques, even though the ionization method is not MALDI. Topics covered in the first part of the review include general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation and arrays. The second part of the review is devoted to applications to various structural types such as oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals. Much of this material is presented in tabular form. The third part of the review covers medical and industrial applications of the technique, studies of enzyme reactions and applications to chemical synthesis. The reported work shows increasing use of combined new techniques such as ion mobility and the enormous impact that MALDI imaging is having. MALDI, although invented over 30 years ago is still an ideal technique for carbohydrate analysis and advancements in the technique and range of applications show no sign of deminishing. © 2020 Wiley Periodicals, Inc.
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Affiliation(s)
- David J Harvey
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom
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8
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Urbániková Ľ. CE16 acetylesterases: in silico analysis, catalytic machinery prediction and comparison with related SGNH hydrolases. 3 Biotech 2021; 11:84. [PMID: 33505839 DOI: 10.1007/s13205-020-02575-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 12/01/2020] [Indexed: 01/23/2023] Open
Abstract
Bioinformatics analysis was focused on unique acetylesterases annotated in the CAZy database within the CE16 family and simultaneously belonging to the SGNH hydrolase superfamily. The CE16 acetylesterases were compared to structurally related SGNH hydrolases: (i) selected members of the CE2, CE3, CE6, CE12 and CE17 family of the CAZy database and (ii) structural representatives of the Lipase_GDSL and Lipase_GDSL_2 families according to the Pfam database. Sequence alignment based on four conserved sequence regions (CSRs) containing active-site residues was used to calculate sequence logos specific for each CE family and to construct a phylogenetic tree. In many members of the CE16 family, aspartic acid from the Ser-His-Asp catalytic triad has been replaced by asparagine, and based on structure-sequence comparison, an alternative catalytic dyad mechanism was predicted for these enzymes. In addition to four conserved regions, CSR-I, CSR-II, CSR-III and CSR-V, containing catalytic and oxyanion-hole residues, CSR-IV was found in the CE16 family as the only CAZy family. Tertiary structures of the characterized CE16 members prepared by homology modeling showed that the α/β/α sandwich fold as well as the topology of their active sites are preserved. The phylogenetic tree and sequence alignment indicate the existence of a subfamily in the CE16 family fully consistent with the known biochemical data. In addition, nonstandard CE16 members that differ from others were analyzed and their active-site residues were predicted. A better understanding of the structure-function relationship of acetylesterases can help in the targeted design of these enzymes for biotechnology. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-020-02575-w.
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9
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Grieco MAB, Haon M, Grisel S, de Oliveira-Carvalho AL, Magalhães AV, Zingali RB, Pereira N, Berrin JG. Evaluation of the Enzymatic Arsenal Secreted by Myceliophthora thermophila During Growth on Sugarcane Bagasse With a Focus on LPMOs. Front Bioeng Biotechnol 2020; 8:1028. [PMID: 32984289 PMCID: PMC7477043 DOI: 10.3389/fbioe.2020.01028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/06/2020] [Indexed: 01/08/2023] Open
Abstract
The high demand for energy and the increase of the greenhouse effect propel the necessity to develop new technologies to efficiently deconstruct the lignocellulosic materials into sugars monomers. Sugarcane bagasse is a rich polysaccharide residue from sugar and alcohol industries. The thermophilic fungus Myceliophthora thermophila (syn. Sporotrichum thermophilum) is an interesting model to study the enzymatic degradation of biomass. The genome of M. thermophila encodes an extensive repertoire of cellulolytic enzymes including 23 lytic polysaccharide monooxygenases (LPMOs) from the Auxiliary Activity family 9 (AA9), which are known to oxidatively cleave the β-1,4 bonds and boost the cellulose conversion in a biorefinery context. To achieve a deeper understanding of the enzymatic capabilities of M. thermophila on sugarcane bagasse, we pretreated this lignocellulosic residue with different methods leading to solids with various cellulose/hemicellulose/lignin proportions and grew M. thermophila on these substrates. The secreted proteins were analyzed using proteomics taking advantage of two mass spectrometry methodologies. This approach unraveled the secretion of many CAZymes belonging to the Glycosyl Hydrolase (GH) and AA classes including several LPMOs that may contribute to the biomass degradation observed during fungal growth. Two AA9 LPMOs, called MtLPMO9B and MtLPMO9H, were selected from secretomic data and enzymatically characterized. Although MtLPMO9B and MtLPMO9H were both active on cellulose, they differed in terms of optimum temperatures and regioselectivity releasing either C1 or C1-C4 oxidized oligosaccharides, respectively. LPMO activities were also measured on sugarcane bagasse substrates with different levels of complexity. The boosting effect of these LPMOs on bagasse sugarcane saccharification by a Trichoderma reesei commercial cocktail was also observed. The partially delignified bagasse was the best substrate considering the oxidized oligosaccharides released and the acid treated bagasse was the best one in terms of saccharification boost.
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Affiliation(s)
- Maria Angela B Grieco
- Laboratório de Desenvolvimento de Bioprocessos, Departamento de Engenharia Bioquímica, Escola de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,INRAE, Faculté des Sciences de Luminy, Aix Marseille Université, UMR 1163 Biodiversité et Biotechnologie Fongiques, Polytech Marseille, Marseille, France
| | - Mireille Haon
- INRAE, Faculté des Sciences de Luminy, Aix Marseille Université, UMR 1163 Biodiversité et Biotechnologie Fongiques, Polytech Marseille, Marseille, France
| | - Sacha Grisel
- INRAE, Faculté des Sciences de Luminy, Aix Marseille Université, UMR 1163 Biodiversité et Biotechnologie Fongiques, Polytech Marseille, Marseille, France
| | - Ana Lucia de Oliveira-Carvalho
- Unidade de Espectrometria de Massas e Proteômica, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Augusto Vieira Magalhães
- Unidade de Espectrometria de Massas e Proteômica, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Russolina B Zingali
- Unidade de Espectrometria de Massas e Proteômica, Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nei Pereira
- Laboratório de Desenvolvimento de Bioprocessos, Departamento de Engenharia Bioquímica, Escola de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jean-Guy Berrin
- INRAE, Faculté des Sciences de Luminy, Aix Marseille Université, UMR 1163 Biodiversité et Biotechnologie Fongiques, Polytech Marseille, Marseille, France
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10
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Puchart V, Gjermansen M, Mastihubová M, Mørkeberg Krogh KB, Biely P. Positional specificity of Flavobacterium johnsoniae acetylxylan esterase and acetyl group migration on xylan main chain. Carbohydr Polym 2020; 232:115783. [DOI: 10.1016/j.carbpol.2019.115783] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/11/2019] [Accepted: 12/24/2019] [Indexed: 02/06/2023]
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11
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Malgas S, Mafa MS, Mkabayi L, Pletschke BI. A mini review of xylanolytic enzymes with regards to their synergistic interactions during hetero-xylan degradation. World J Microbiol Biotechnol 2019; 35:187. [PMID: 31728656 DOI: 10.1007/s11274-019-2765-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/06/2019] [Indexed: 10/25/2022]
Abstract
This review examines the recent models describing the mode of action of various xylanolytic enzymes and how these enzymes can be applied (sequentially or simultaneously) with their distinctive roles in mind to achieve efficient xylan degradation. With respect to homeosynergy, synergism appears to be as a result of β-xylanase and/or oligosaccharide reducing-end β-xylanase liberating xylo-oligomers (XOS) that are preferred substrates of the processive β-xylosidase. With regards to hetero-synergism, two cross relationships appear to exist and seem to be the reason for synergism between the enzymes during xylan degradation. These cross relations are the debranching enzymes such as α-glucuronidase or side-chain cleaving enzymes such as carbohydrate esterases (CE) removing decorations that would have hindered back-bone-cleaving enzymes, while backbone-cleaving-enzymes liberate XOS that are preferred substrates of the debranching and side-chain-cleaving enzymes. This interaction is demonstrated by high yields in co-production of xylan substituents such as arabinose, glucuronic acid and ferulic acid, and XOS. Finally, lytic polysaccharide monooxygenases (LPMO) have also been implicated in boosting whole lignocellulosic biomass or insoluble xylan degradation by glycoside hydrolases (GH) by possibly disrupting entangled xylan residues. Since it has been observed that the same enzyme (same Enzyme Commission, EC, classification) from different GH or CE and/or AA families can display different synergistic interactions with other enzymes due to different substrate specificities and properties, in this review, we propose an approach of enzyme selection (and mode of application thereof) during xylan degradation, as this can improve the economic viability of the degradation of xylan for producing precursors of value added products.
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Affiliation(s)
- Samkelo Malgas
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa
| | - Mpho S Mafa
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa.,Protein Structure-Function Research Unit (PSFRU), School of Molecular and Cell Biology, Wits University, Johannesburg, Gauteng, 2000, South Africa
| | - Lithalethu Mkabayi
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa
| | - Brett I Pletschke
- Enzyme Science Programme (ESP), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, Eastern Cape, 6140, South Africa.
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12
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Puchart V, Mørkeberg Krogh KB, Biely P. Glucuronoxylan 3-O-acetylated on uronic acid-substituted xylopyranosyl residues and its hydrolysis by GH10, GH11 and GH30 endoxylanases. Carbohydr Polym 2019; 205:217-224. [DOI: 10.1016/j.carbpol.2018.10.043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/11/2018] [Accepted: 10/14/2018] [Indexed: 11/26/2022]
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13
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Lassfolk R, Rahkila J, Johansson MP, Ekholm FS, Wärnå J, Leino R. Acetyl Group Migration across the Saccharide Units in Oligomannoside Model Compound. J Am Chem Soc 2019; 141:1646-1654. [PMID: 30586298 DOI: 10.1021/jacs.8b11563] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Acetylated oligosaccharides are common in nature. While they are involved in several biochemical and biological processes, the role of the acetyl groups and the complexity of their migration has largely gone unnoticed. In this work, by combination of organic synthesis, NMR spectroscopy and quantum chemical modeling, we show that acetyl group migration is a much more complex phenomenon than previously known. By use of synthetic oligomannoside model compounds, we demonstrate, for the first time, that the migration of acetyl groups in oligosaccharides and polysaccharides may not be limited to transfer within a single monosaccharide moiety, but may also involve migration over a glycosidic bond between two different saccharide units. The observed phenomenon is not only interesting from the chemical point of view, but it also raises new questions about the potential biological role of acylated carbohydrates in nature.
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Affiliation(s)
- Robert Lassfolk
- Johan Gadolin Process Chemistry Centre, Laboratory of Organic Chemistry, Åbo Akademi University , FI-20500 Åbo , Finland
| | - Jani Rahkila
- Johan Gadolin Process Chemistry Centre, Laboratory of Organic Chemistry, Åbo Akademi University , FI-20500 Åbo , Finland
| | - Mikael P Johansson
- Department of Chemistry , University of Helsinki , FI-00014 Helsinki , Finland.,Helsinki Institute of Sustainability Science, HELSUS , FI-00014 Helsinki , Finland
| | - Filip S Ekholm
- Department of Chemistry , University of Helsinki , FI-00014 Helsinki , Finland
| | - Johan Wärnå
- Johan Gadolin Process Chemistry Centre, Laboratory of Industrial Chemistry and Reaction Engineering, Åbo Akademi University , FI-20500 Åbo , Finland
| | - Reko Leino
- Johan Gadolin Process Chemistry Centre, Laboratory of Organic Chemistry, Åbo Akademi University , FI-20500 Åbo , Finland
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14
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Action of different types of endoxylanases on eucalyptus xylan in situ. Appl Microbiol Biotechnol 2018; 102:1725-1736. [PMID: 29302718 DOI: 10.1007/s00253-017-8722-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/13/2017] [Accepted: 12/17/2017] [Indexed: 10/18/2022]
Abstract
Most studies of the mode of action of industrially important endoxylanases have been done on alkali extracted-plant xylan. In just few cases, the native form of the polysaccharide, acetylated xylan, was used as a substrate. In this work action of xylanases belonging to three glycoside hydrolase families, GH10, GH11, and GH30 was investigated on acetylglucuronoxylan directly in hardwood cell walls. Powdered eucalyptus wood was used as xylanase substrate. Enzyme-generated fragments were characterized by TLC, MALDI ToF MS, and NMR spectroscopy. All three xylanases generated from eucalyptus wood powder acetylated xylooligosaccharides. Those released by GH10 enzyme were the shortest, and those released by GH30 xylanase were of the largest diversity. For GH30 xylanase the 4-O-methyl-D-glucuronic acid (MeGlcA) side residues function as substrate specificity determinants regardless the acetylation of the neighboring hydroxyl group. Much simpler xylooligosaccharide patterns were observed when xylanases were applied in combination with carbohydrate esterase family 6 acetylxylan esterase. In the presence of the esterase, all aldouronic acids remained 3-O-acetylated on the xylopyranosyl (Xylp) residue substituted with MeGlcA. The 3-O-acetyl group, in contrast to the acetyl groups of otherwise unsubstituted Xylp residues, does not affect the mode of action of endoxylanases, but contributes to recalcitrance of the acidic xylan fragments. The results confirm importance of acetylxylan esterases in microbial degradation of acetylated hardwood glucuronoxylan. They also point to still unresolved question of efficient enzymatic removal of the 3-O-acetyl group on MeGlcA-substituted Xylp residues negatively affecting the saccharification yields.
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Razeq FM, Jurak E, Stogios PJ, Yan R, Tenkanen M, Kabel MA, Wang W, Master ER. A novel acetyl xylan esterase enabling complete deacetylation of substituted xylans. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:74. [PMID: 29588659 PMCID: PMC5863359 DOI: 10.1186/s13068-018-1074-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 03/09/2018] [Indexed: 05/02/2023]
Abstract
BACKGROUND Acetylated 4-O-(methyl)glucuronoxylan (GX) is the main hemicellulose in deciduous hardwood, and comprises a β-(1→4)-linked xylopyranosyl (Xylp) backbone substituted by both acetyl groups and α-(1→2)-linked 4-O-methylglucopyranosyluronic acid (MeGlcpA). Whereas enzymes that target singly acetylated Xylp or doubly 2,3-O-acetyl-Xylp have been well characterized, those targeting (2-O-MeGlcpA)3-O-acetyl-Xylp structures in glucuronoxylan have remained elusive. RESULTS An unclassified carbohydrate esterase (FjoAcXE) was identified as a protein of unknown function from a polysaccharide utilization locus (PUL) otherwise comprising carbohydrate-active enzyme families known to target xylan. FjoAcXE was shown to efficiently release acetyl groups from internal (2-O-MeGlcpA)3-O-acetyl-Xylp structures, an activity that has been sought after but lacking in known carbohydrate esterases. FjoAcXE action boosted the activity of α-glucuronidases from families GH67 and GH115 by five and nine times, respectively. Moreover, FjoAcXE activity was not only restricted to GX, but also deacetylated (3-O-Araf)2-O-acetyl-Xylp of feruloylated xylooligomers, confirming the broad substrate range of this new carbohydrate esterase. CONCLUSION This study reports the discovery and characterization of the novel carbohydrate esterase, FjoAcXE. In addition to cleaving singly acetylated Xylp, and doubly 2,3-O-acetyl-Xylp, FjoAcXE efficiently cleaves internal 3-O-acetyl-Xylp linkages in (2-O-MeGlcpA)3-O-acetyl-Xylp residues along with densely substituted and branched xylooligomers; activities that until now were missing from the arsenal of enzymes required for xylan conversion.
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Affiliation(s)
- Fakhria M. Razeq
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 Canada
| | - Edita Jurak
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 00076 Aalto Espoo, Finland
| | - Peter J. Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 Canada
| | - Ruoyu Yan
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 Canada
| | - Maija Tenkanen
- Department of Food and Environmental Sciences, University of Helsinki, P.O. Box 66, 00014 Helsinki, Finland
| | - Mirjam A. Kabel
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Weijun Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 Canada
| | - Emma R. Master
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, ON M5S 3E5 Canada
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, 00076 Aalto Espoo, Finland
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Xie C, Gong W, Zhu Z, Yan L, Hu Z, Peng Y. Comparative transcriptomics of Pleurotus eryngii reveals blue-light regulation of carbohydrate-active enzymes (CAZymes) expression at primordium differentiated into fruiting body stage. Genomics 2017; 110:201-209. [PMID: 28970048 DOI: 10.1016/j.ygeno.2017.09.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/10/2017] [Accepted: 09/27/2017] [Indexed: 02/03/2023]
Abstract
Blue light is an important environmental factor which could induce mushroom primordium differentiation and fruiting body development. However, the mechanisms of Pleurotus eryngii primordium differentiation and development induced by blue light are still unclear. The CAZymes (carbohydrate-active enzymes) play important roles in degradation of renewable lignocelluloses to provide carbohydrates for fungal growth, development and reproduction. In the present research, the expression profiles of genes were measured by comparison between the Pleurotus eryngii at primordium differentiated into fruiting body stage after blue light stimulation and dark using high-throughput sequencing approach. After assembly and compared to the Pleurotus eryngii reference genome, 11,343 unigenes were identified. 539 differentially expressed genes including white collar 2 type of transcription factor gene, A mating type protein gene, MAP kinase gene, oxidative phosphorylation associated genes, CAZymes genes and other metabolism related genes were identified during primordium differentiated into fruiting body stage after blue light stimulation. KEGG results showed that carbon metabolism, glycolysis/gluconeogenesis and biosynthesis of amino acids pathways were affected during blue light inducing primordia formation. Most importantly, 319 differentially expressed CAZymes participated in carbon metabolism were identified. The expression patterns of six representative CAZymes and laccase genes were further confirmed by qRT-PCR. Enzyme activity results indicated that the activities of CAZymes and laccase were affected in primordium differentiated into fruiting body under blue light stimulation. In conclusion, the comprehensive transcriptome and CAZymes of Pleurotus eryngii at primordium differentiated into fruiting body stage after blue light stimulation were obtained. The biological insights gained from this integrative system represent a valuable resource for future genomic studies on this commercially important mushroom.
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Affiliation(s)
- Chunliang Xie
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China
| | - Wenbing Gong
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China
| | - Zuohua Zhu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China
| | - Li Yan
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China
| | - Zhenxiu Hu
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China
| | - Yuande Peng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, People's Republic of China.
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17
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Mai-Gisondi G, Maaheimo H, Chong SL, Hinz S, Tenkanen M, Master E. Functional comparison of versatile carbohydrate esterases from families CE1, CE6 and CE16 on acetyl-4-O-methylglucuronoxylan and acetyl-galactoglucomannan. Biochim Biophys Acta Gen Subj 2017; 1861:2398-2405. [PMID: 28591625 DOI: 10.1016/j.bbagen.2017.06.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 05/30/2017] [Accepted: 06/02/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND The backbone structure of many hemicelluloses is acetylated, which presents a challenge when the objective is to convert corresponding polysaccharides to fermentable sugars or else recover hemicelluloses for biomaterial applications. Carbohydrate esterases (CE) can be harnessed to overcome these challenges. METHODS Enzymes from different CE families, AnAcXE (CE1), OsAcXE (CE6), and MtAcE (CE16) were compared based on action and position preference towards acetyl-4-O-methylglucuronoxylan (MGX) and acetyl-galactoglucomannan (GGM). To determine corresponding positional preferences, the relative rate of acetyl group released by each enzyme was analyzed by real time 1H NMR. RESULTS AnAcXE (CE1) showed lowest specific activity towards MGX, where OsAcXE (CE6) and MtAcE were approximately four times more active than AnAcXE (CE1). MtAcE (CE16) was further distinguished by demonstrating 100 times higher activity on GGM compared to AnAcXE (CE1) and OsAcXE (CE6), and five times higher activity on GGM than MGX. Following 24h incubation, all enzymes removed between 78 and 93% of total acetyl content from MGX and GGM, where MtAcE performed best on both substrates. MAJOR CONCLUSIONS Considering action on MGX, all esterases showed preference for doubly substituted xylopyranosyl residues (2,3-O-acetyl-Xylp). Considering action on GGM, OsAcXE (CE6) preferentially targeted 2-O-acetyl-mannopyranosyl residues (2-O-acetyl-Manp) whereas AnAcXE (CE1) demonstrated highest activity towards 3-O-acetyl-Manp positions; regiopreference of MtAcE (CE16) on GGM was less clear. GENERAL SIGNIFICANCE The current comparative analysis identifies options to control the position of acetyl group release at initial stages of reaction, and enzyme combinations likely to accelerate deacetylation of major hemicellulose sources.
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Affiliation(s)
- Galina Mai-Gisondi
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, FI-00076 Espoo, Finland
| | - Hannu Maaheimo
- VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 Espoo, Finland
| | - Sun-Li Chong
- Department of Food and Environmental Sciences, University of Helsinki, Latokartanonkaari 11, FI-00014 Helsinki, Finland
| | - Sandra Hinz
- DuPont Industrial Biosciences, Nieuwe Kanaal 7-S, 6709 PA, Wageningen, The Netherlands
| | - Maija Tenkanen
- Department of Food and Environmental Sciences, University of Helsinki, Latokartanonkaari 11, FI-00014 Helsinki, Finland
| | - Emma Master
- Department of Bioproducts and Biosystems, Aalto University, Kemistintie 1, FI-00076 Espoo, Finland; Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada.
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Towards enzymatic breakdown of complex plant xylan structures: State of the art. Biotechnol Adv 2016; 34:1260-1274. [PMID: 27620948 DOI: 10.1016/j.biotechadv.2016.09.001] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/02/2016] [Accepted: 09/07/2016] [Indexed: 02/07/2023]
Abstract
Significant progress over the past few years has been achieved in the enzymology of microbial degradation and saccharification of plant xylan, after cellulose being the most abundant natural renewable polysaccharide. Several new types of xylan depolymerizing and debranching enzymes have been described in microorganisms. Despite the increasing variety of known glycoside hydrolases and carbohydrate esterases, some xylan structures still appear quite recalcitrant. This review focuses on the mode of action of different types of depolymerizing endoxylanases and their cooperation with β-xylosidase and accessory enzymes in breakdown of complex highly branched xylan structures. Emphasis is placed on the enzymatic hydrolysis of alkali-extracted deesterified polysaccharide as well as acetylated xylan isolated from plant cell walls under non-alkaline conditions. It is also shown how the combination of selected endoxylanases and debranching enzymes can determine the nature of prebiotic xylooligosaccharides or lead to complete hydrolysis of the polysaccharide. The article also highlights the possibility for discovery of novel xylanolytic enzymes, construction of multifunctional chimeric enzymes and xylanosomes in parallel with increasing knowledge on the fine structure of the polysaccharide.
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