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Embaby AM, Mahmoud HE. Recombinant acetylxylan esterase of Halalkalibacterium halodurans NAH-Egypt: molecular and biochemical study. AMB Express 2022; 12:135. [DOI: 10.1186/s13568-022-01476-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/15/2022] [Indexed: 11/10/2022] Open
Abstract
AbstractAcetylxylan esterase plays a crucial role in xylan hydrolysis as the acetyl side-groups restrict endoxylanase action by stearic hindrance. In this study, an acetylxylan esterase (AXE-HAS10: 960 bp & 319 a.a) putative ORF from Halalkalibacterium halodurans NAH-Egypt was extensively studied through heterologous overexpression in Escherichia coli, biochemical characterization, and structural modeling. The AXE-HAS10 tertiary structure was predicted by the Local Meta Threading Server. AXE-HAS10 belongs to the carbohydrate esterase Family 7. Purified to homogeneity AXE-HAS10 showed specific activity (36.99 U/mg), fold purification (11.42), and molecular mass (41.39 kDa). AXE-HAS10 showed optimal pH (8.5) and temperature (40 oC). After 15 h of incubation at pH 7.0–9.0, AXE-HAS10 maintained 100% activity. After 120 min at 35 and 40 oC, the retained activity was 80 and 50%, respectively. At 10 mM Mn2+, Fe3+, K+, and Ca2+ after 30 min, retained activity was 329 ± 15, 212 ± 5.2, 123 ± 1.4, and 120 ± 3.0%, respectively. After 30 min of preincubation with triton x-100, SDS, and CTAB at 0.1% (v/v), the retained activity was 150 ± 19, 88 ± 4, and 82 ± 7%, respectively. At 6.0 M NaCl after 30 min, retained activity was 58%. A 1.44-fold enhancement of beechwood xylan hydrolysis was achieved by AXE-HAS10 and Penicillium chrysogenum DSM105774 β-xylanase concurrently. Present data underpins AXE-HAS10 as a promising AXE for industrial exploitation.
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Xu J, Zhao X, Yao Q, Zong W, Dai S, Deng Z, Liu S, Yun J, Yang X, Li H. Cloning, characterization of a novel acetyl xylan esterase, and its potential application on wheat straw utilization. ALL LIFE 2021. [DOI: 10.1080/26895293.2021.1947393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Jin Xu
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Xiaoshen Zhao
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Qian Yao
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Wei Zong
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Shuang Dai
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Zujun Deng
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
| | - Shan Liu
- Guangzhou Basic Clean Cosmetics Manufacturing Co., Ltd, Guangzhou, People’s Republic of China
| | - Jeonyun Yun
- Guangzhou Basic Clean Cosmetics Manufacturing Co., Ltd, Guangzhou, People’s Republic of China
| | - Xiong Yang
- Guangzhou Basic Clean Cosmetics Manufacturing Co., Ltd, Guangzhou, People’s Republic of China
| | - He Li
- School of Life Sciences and Biopharmaceuticals, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
- Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, People’s Republic of China
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Wang Z, Pawar PMA, Derba-Maceluch M, Hedenström M, Chong SL, Tenkanen M, Jönsson LJ, Mellerowicz EJ. Hybrid Aspen Expressing a Carbohydrate Esterase Family 5 Acetyl Xylan Esterase Under Control of a Wood-Specific Promoter Shows Improved Saccharification. FRONTIERS IN PLANT SCIENCE 2020; 11:380. [PMID: 32322259 PMCID: PMC7156598 DOI: 10.3389/fpls.2020.00380] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/17/2020] [Indexed: 05/12/2023]
Abstract
Fast-growing broad-leaf tree species can serve as feedstocks for production of bio-based chemicals and fuels through biochemical conversion of wood to monosaccharides. This conversion is hampered by the xylan acetylation pattern. To reduce xylan acetylation in the wood, the Hypocrea jecorina acetyl xylan esterase (HjAXE) from carbohydrate esterase (CE) family 5 was expressed in hybrid aspen under the control of the wood-specific PtGT43B promoter and targeted to the secretory pathway. The enzyme was predicted to deacetylate polymeric xylan in the vicinity of cellulose due to the presence of a cellulose-binding module. Cell-wall-bound protein fractions from developing wood of transgenic plants were capable of releasing acetyl from finely ground wood powder, indicative of active AXE present in cell walls of these plants, whereas no such activity was detected in wild-type plants. The transgenic lines grew in height and diameter as well as wild-type trees, whereas their internodes were slightly shorter, indicating higher leaf production. The average acetyl content in the wood of these lines was reduced by 13%, mainly due to reductions in di-acetylated xylose units, and in C-2 and C-3 mono-acetylated xylose units. Analysis of soluble cell wall polysaccharides revealed a 4% reduction in the fraction of xylose units and an 18% increase in the fraction of glucose units, whereas the contents of cellulose and lignin were not affected. Enzymatic saccharification of wood from transgenic plants resulted in 27% higher glucose yield than for wild-type plants. Brunauer-Emmett-Teller (BET) analysis and Simons' staining pointed toward larger surface area and improved cellulose accessibility for wood from transgenic plants compared to wood from wild-type plants, which could be achieved by HjAXE deacetylating xylan bound to cellulose. The results show that CE5 family can serve as a source of enzymes for in planta reduction of recalcitrance to saccharification.
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Affiliation(s)
- Zhao Wang
- Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, Umeå, Sweden
| | | | - Marta Derba-Maceluch
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Mattias Hedenström
- Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, Umeå, Sweden
| | - Sun-Li Chong
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Maija Tenkanen
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Leif J. Jönsson
- Department of Chemistry, KBC Chemical-Biological Centre, Umeå University, Umeå, Sweden
| | - Ewa J. Mellerowicz
- Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, Sweden
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Sista Kameshwar AK, Qin W. Understanding the structural and functional properties of carbohydrate esterases with a special focus on hemicellulose deacetylating acetyl xylan esterases. Mycology 2018; 9:273-295. [PMID: 30533253 PMCID: PMC6282417 DOI: 10.1080/21501203.2018.1492979] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/21/2018] [Indexed: 11/29/2022] Open
Abstract
Acetyl and methyl esterifications are two major naturally found substitutions in the plant cell-wall polysaccharides. The non-cellulosic plant cell-wall polysaccharides such as pectin and hemicellulose are differentially esterified by the O-acetyl and methyl groups to cease the action of various hydrolytic enzymes secreted by different fungi and bacterial species. Thus, microorganisms have emerged with a special class of enzymes known as carbohydrate esterases (CE). The CE catalyse O-de, N-deacetylation of acetylated saccharide residues (esters or amides, where sugars play the role of alcohol/amine/acid). Carbohydrate active enzyme (CAZy) database has classified CE into 16 classes, of which hemicellulose deacetylating CE were grouped into eight classes (CE-1 to CE-7 and CE-16). Various plant biomass degrading fungi and bacteria secretes acetyl xylan esterases (AcXE); however, these enzymes exhibit varied substrate specificities. AcXE and xylanases-coupled pretreatment methods exhibit significant applications, such as enhancing animal feedstock, baking industry, production of food additives, paper and pulp, xylitol production and biorefinery-based industries, respectively. Thus, understanding the structural and functional properties of acetyl xylan esterase will significantly aid in developing the efficient AcXE with wide range of industrial applications.
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Affiliation(s)
| | - Wensheng Qin
- Department of Biology, Lakehead University, Thunder Bay, Ontario, Canada
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Bischof RH, Ramoni J, Seiboth B. Cellulases and beyond: the first 70 years of the enzyme producer Trichoderma reesei. Microb Cell Fact 2016; 15:106. [PMID: 27287427 PMCID: PMC4902900 DOI: 10.1186/s12934-016-0507-6] [Citation(s) in RCA: 280] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 06/01/2016] [Indexed: 11/10/2022] Open
Abstract
More than 70 years ago, the filamentous ascomycete Trichoderma reesei was isolated on the Solomon Islands due to its ability to degrade and thrive on cellulose containing fabrics. This trait that relies on its secreted cellulases is nowadays exploited by several industries. Most prominently in biorefineries which use T. reesei enzymes to saccharify lignocellulose from renewable plant biomass in order to produce biobased fuels and chemicals. In this review we summarize important milestones of the development of T. reesei as the leading production host for biorefinery enzymes, and discuss emerging trends in strain engineering. Trichoderma reesei has very recently also been proposed as a consolidated bioprocessing organism capable of direct conversion of biopolymeric substrates to desired products. We therefore cover this topic by reviewing novel approaches in metabolic engineering of T. reesei.
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Affiliation(s)
- Robert H Bischof
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH c/o Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria
| | - Jonas Ramoni
- Molecular Biotechnology, Research Area Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria
| | - Bernhard Seiboth
- Austrian Centre of Industrial Biotechnology (ACIB) GmbH c/o Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria. .,Molecular Biotechnology, Research Area Biochemical Technology, Institute of Chemical Engineering, TU Wien, Gumpendorferstraße 1a, 1060, Vienna, Austria.
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Watanabe M, Yoshida E, Fukada H, Inoue H, Tokura M, Ishikawa K. Characterization of a feruloyl esterase B from Talaromyces cellulolyticus. Biosci Biotechnol Biochem 2015; 79:1845-51. [DOI: 10.1080/09168451.2015.1058700] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Abstract
A feruloyl esterase catalyzes the hydrolysis of the 4-hydroxy-3-methoxycinnamoyl (feruloyl) group from esterified sugars in plant cell walls. Talaromyces cellulolyticus is a high cellulolytic-enzyme producing fungus. However, there is no report for feruloyl esterase activity of T. cellulolyticus. Analysis of the genome database of T. cellulolyticus identified a gene encoding a putative feruloyl esterase B. The recombinant enzyme was prepared using a T. cellulolyticus homologous expression system and characterized. The purified enzyme exhibited hydrolytic activity toward p-nitrophenyl acetate, p-nitrophenyl trans-ferulate, methyl ferulate, rice husk, and bagasse. HPLC assays showed that the enzyme released ferulic acid and p-coumaric acid from hydrothermal-treated rice husk and bagasse. Trichoderma sp. is well-known high cellulolytic-enzyme producing fungus useful for the lignocellulosic biomass saccharification. Interestingly, no feruloyl esterase has been reported from Trichoderma sp. The results show that this enzyme is expected to be industrially useful for biomass saccharification.
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Affiliation(s)
- Masahiro Watanabe
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi-hiroshima, Japan
| | - Erika Yoshida
- Frontier Research Labs, Institute for Innovation Ajinomoto Co., Inc., Kawasaki, Japan
| | - Hiroaki Fukada
- Frontier Research Labs, Institute for Innovation Ajinomoto Co., Inc., Kawasaki, Japan
| | - Hiroyuki Inoue
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi-hiroshima, Japan
| | - Mitsunori Tokura
- Frontier Research Labs, Institute for Innovation Ajinomoto Co., Inc., Kawasaki, Japan
| | - Kazuhiko Ishikawa
- Biomass Refinery Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Higashi-hiroshima, Japan
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Stepanova EV, Belyanin ML, Filimonov VD, Valiev RR, Gruner M, Rogachev V. The first example of a one-step synthesis of 2'-O-acetyl aryl-D-glucopyranosides. Carbohydr Res 2015; 409:36-40. [PMID: 25950119 DOI: 10.1016/j.carres.2015.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/27/2015] [Accepted: 03/30/2015] [Indexed: 11/29/2022]
Abstract
A selective acidic system for partial deacetylation of phenolic d-glucopyranosides per-acetates has been developed that allows synthesis of the corresponding 2'-O-acetyl-D-glucosides. Many disadvantages of generally used methods for preparing such mono-acyl derivatives involving multistep procedures or the use of enzymes are avoided. The ion at m/z 289 in mass spectra of their TMS derivatives indicates a particular and characteristic fragmentation pattern of these 2'-O-acetyl derivatives of d-glucopyranosides. Quantum-chemical calculations applying B3LYP/TZVP level of theory revealed the stability of 2'-O-acetyl glucopyranoside if compare with 3'-, 4'- and 6'- O-acetyl glucopyanosides.
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Affiliation(s)
- Elena V Stepanova
- Department of Biotechnology and Organic Chemistry, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia.
| | - Maxim L Belyanin
- Department of Biotechnology and Organic Chemistry, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia
| | - Victor D Filimonov
- Department of Biotechnology and Organic Chemistry, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia
| | - Rashid R Valiev
- Department of General and Inorganic Chemistry, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia; Tomsk State University, Lenina Avenue 36, Tomsk 634050, Russia
| | - Margit Gruner
- Professur für Organische Chemie I, Technische Universität Dresden, 01062 Dresden, Germany
| | - Victor Rogachev
- Department of Biotechnology and Organic Chemistry, National Research Tomsk Polytechnic University, 30 Lenin Avenue, Tomsk 634050, Russia; Professur für Organische Chemie I, Technische Universität Dresden, 01062 Dresden, Germany
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Watanabe M, Fukada H, Inoue H, Ishikawa K. Crystal structure of an acetylesterase fromTalaromyces cellulolyticusand the importance of a disulfide bond near the active site. FEBS Lett 2015; 589:1200-6. [DOI: 10.1016/j.febslet.2015.03.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/10/2015] [Accepted: 03/17/2015] [Indexed: 11/29/2022]
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Redistribution of acetyl groups on the non-reducing end xylopyranosyl residues and their removal by xylan deacetylases. Appl Microbiol Biotechnol 2014; 99:3865-73. [PMID: 25381188 DOI: 10.1007/s00253-014-6160-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 10/09/2014] [Accepted: 10/12/2014] [Indexed: 01/16/2023]
Abstract
BACKGROUND Monoacetylated xylosyl residues of the main hardwood hemicellulose acetylglucuronoxylan undergo acetyl group migration between positions 2 and 3, and predominantly to position 4 of the non-reducing end xylopyranosyl (NRE-Xylp) residues which are amplified by saccharifying enzymes. On monoacetylated non-reducing end xylopyranosyl (NRE-Xylp) residues of xylooligosaccharides the acetyl group migrates predominantly to position 4 and hinders their hydrolysis by β-xylosidase. METHODS Acetyl migration on the NRE-Xylp residues and their enzymatic deacetylation by various xylan deacetylases was followed by (1)H-NMR spectroscopy and TLC. RESULTS A 5-min heat treatment of 4-nitrophenyl 3-O-acetyl-β-D-xylopyranoside was sufficient to establish equilibrium between monoacetate derivatives acetylated at positions 2, 3 and 4. Rapid acetyl migration along the NRE-Xylp ring at elevated temperature was confirmed in derivatives of methyl β-1,4-xylotrioside (Xyl3Me) monoacetylated solely on the NRE-Xylp residue, the analogues of naturally occurring acetylated xylooligosaccharides. The Xyl3Me monoacetates were used as substrates to study regioselectivity of the NRE-Xylp residue deacetylation by various acetylxylan esterases (AcXEs) of distinct carbohydrate esterase (CE) families. CE1, CE4 and CE6 AcXEs hydrolyzed considerably faster the 2″-O-acetyl derivative than the 3″-O-acetyl derivative. In contrast, the CE16 acetyl esterase preferred to attack the ester bond at position 3 followed by position 4. CONCLUSIONS Redistribution of acetyl group on the NRE-Xylp residues is extremely rapid at elevated temperature and includes the formation of 4-acetate. Regioselectivity of AcXEs and CE16 acetyl esterase on these monoacetates is complementary. GENERAL SIGNIFICANCE The formation of all isomers of acetylated xylosyl residues must be taken into account after a long-term incubation of acetylxylan and acetylated xylooligosaccharides solutions or upon their treatment at elevated temperatures. This phenomenon emphasizes requirement of both types of xylan deacetylases to enable a rapid saccharification of xylooligosaccharides by glycoside hydrolases.
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Biely P, Cziszárová M, Uhliariková I, Agger JW, Li XL, Eijsink VGH, Westereng B. Mode of action of acetylxylan esterases on acetyl glucuronoxylan and acetylated oligosaccharides generated by a GH10 endoxylanase. Biochim Biophys Acta Gen Subj 2013; 1830:5075-86. [PMID: 23891707 DOI: 10.1016/j.bbagen.2013.07.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Substitutions on the xylan main chain are widely accepted to limit plant cell wall degradability and acetylations are considered as one of the most important obstacles. Hence, understanding the modes of action of a range of acetylxylan esterases (AcXEs) is of ample importance not only to increase the understanding of the enzymology of plant decay/bioremediation but also to enable efficient bioconversion of plant biomass. METHODS In this study, the modes of action of acetylxylan esterases (AcXEs) belonging to carbohydrate esterase (CE) families 1, 4, 5 and 6 on xylooligosaccharides generated from hardwood acetyl glucuronoxylan were compared using MALDI ToF MS. Supporting data were obtained by following enzymatic deacetylation by (1)H NMR spectroscopy. CONCLUSIONS None of the used enzymes were capable of complete deacetylation, except from linear xylooligosaccharides which were completely deacetylated by some of the esterases in the presence of endoxylanase. A clear difference was observed between the performance of the serine-type esterases of CE families 1, 5 and 6, and the aspartate-metalloesterases of family CE4. The difference is mainly due to the inability of CE4 AcXEs to catalyze deacetylation of 2,3-di-O-acetylated xylopyranosyl residues. Complete deacetylation of a hardwood acetyl glucuronoxylan requires additional deacetylating enzyme(s). GENERAL SIGNIFICANCE The results contribute to the understanding of microbial degradation of plant biomass and outline the way to achieve complete saccharification of plant hemicelluloses which did not undergo alkaline pretreatment.
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Affiliation(s)
- Peter Biely
- Institute of Chemistry, Center of Glycomics, Slovak Academy of Sciences, Dúbravská cesta 9, 84538 Bratislava, Slovakia.
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Biely P. Microbial carbohydrate esterases deacetylating plant polysaccharides. Biotechnol Adv 2012; 30:1575-88. [PMID: 22580218 DOI: 10.1016/j.biotechadv.2012.04.010] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 04/19/2012] [Accepted: 04/30/2012] [Indexed: 11/29/2022]
Abstract
Several plant polysaccharides are partially esterified with acetic acid. One of the roles of this modification is protection of plant cell walls against invading microorganisms. Acetylation of glycosyl residues of polysaccharides prevents hydrolysis of their glycosidic linkages by the corresponding glycoside hydrolases. In this way the acetylation also represents an obstacle of enzymatic saccharification of plant hemicelluloses to fermentable sugars which appears to be a hot topic of current research. We can eliminate this obstacle by alkaline extraction or pretreatment leading to saponification of ester linkages. However, this task has been accomplished in a different way in the nature. The acetyl groups became targets of microbial carbohydrate esterases that evolved to overcome the complexity of the plant cell walls and that cooperate with glycoside hydrolases in plant polysaccharide degradation. This article concentrates on enzymes deacetylating plant hemicelluloses excluding pectin. They are currently grouped in at least 8 families, specifically in CE families 1-7 and 16, originally assigned as acetylxylan esterases, the enzymes acting on hardwood acetyl glucuronoxylan and its fragments generated by endo-β-1,4-xylanases. There are esterases deacetylating softwood galactoglucomannan, but they have not been classified yet. The enzymes present in CE families 1-7 differ in structure and substrate and positional specificity. There are families behaving as endo-type and exo-type deacetylates, i.e. esterases deacetylating internal sugar residues of partially acetylated polysaccharides and also esterases deacetylating non-reducing end sugar residues in oligosaccharides. With one exception, the enzymes of all mentioned CE families belong to serine type esterases. CE family 4 harbors enzymes that are metal-dependent aspartic esterases. Three-dimensional structures have been solved for members of the first seven CE families, however, there is still insufficient knowledge about their substrate specificity and real physiological role. Current knowledge on catalytic properties of the selected families of CEs is summarized in this review. Some of the families are emerging also as new biocatalysts for regioselective acylation and deacylation of carbohydrates.
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Affiliation(s)
- Peter Biely
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 845 38 Bratislava, Slovakia.
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Constitutive expression of Thermobifida fusca thermostable Acetylxylan Esterase gene in Pichia pastoris. Int J Mol Sci 2010; 11:5143-51. [PMID: 21614198 PMCID: PMC3100850 DOI: 10.3390/ijms11125143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 12/01/2010] [Accepted: 12/09/2010] [Indexed: 11/17/2022] Open
Abstract
A gene encoding the thermostable acetylxylan esterase (AXE) in Thermobifida fusca NTU22 was amplified by PCR, sequenced and cloned into the Pichia pastoris X-33 host strain using the vector pGAPZαA, allowing constitutive expression and secretion of the protein. Recombinant expression resulted in high levels of extracellular AXE production, as high as 526 U/mL in the Hinton flask culture broth. The purified enzyme showed a single band at about 28 kDa by SDS-polyacrylamide gel electrophoresis after being treated with endo-β-N-acetylglycosaminidase H; this agrees with the predicted size based on the nucleotide sequence. About 70% of the original activity remained after heat treatment at 60 °C for three hours. The optimal pH and temperature of the purified enzyme were 8.0 and 60 °C, respectively. The properties of the purified AXE from the P. pastoris transformant are similar to those of the AXE from an E. coli transformant.
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Heterologous expression of thermostable acetylxylan esterase gene from Thermobifida fusca and its synergistic action with xylanase for the production of xylooligosaccharides. Biochem Biophys Res Commun 2010; 400:718-23. [DOI: 10.1016/j.bbrc.2010.08.136] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 08/29/2010] [Indexed: 10/19/2022]
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Lindorfer J, Steinmüller H, Auer W, Nidetzky B, Loncar E, Jäger A, Eder A, Hofer B. Untersuchungen zur Herstellung von Bioethanol und Biogas aus Lignocelluloserohstoffen nach Vorbehandlung mit Steam Explosion und Cellulasen. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.201000049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Ding S, Cao J, Zhou R, Zheng F. Molecular cloning, and characterization of a modular acetyl xylan esterase from the edible straw mushroomVolvariella volvacea. FEMS Microbiol Lett 2007; 274:304-10. [PMID: 17623028 DOI: 10.1111/j.1574-6968.2007.00844.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
A new Volvariella volvacea gene encoding an acetyl xylan esterase (designated as Vvaxe1) was cloned and expressed in Pichia pastoris. The cDNA contained an ORF of 1047 bp encoding 349 amino acids with a calculated mass of 39 990 Da. VvAXE1 is a modular enzyme consisting of an N-terminal signal peptide, a catalytic domain, and a cellulose-binding domain. The amino acid sequence of the enzyme exhibited a high degree of similarity to cinnamoyl esterase B from Penicillium funiculosum, and acetyl xylan esterases from Aspergillus oryzae, Penicillium purpurogenum, and Aspergillus ficuum. Recombinant acetyl xylan esterase released acetate from several acetylated substrates including beta-d-xylose tetraacetate and acetylated xylan. No activity was detectable on p-nitrophenyl acetate. Enzyme-catalyzed hydrolysis of 4-methylumbelliferyl acetate was maximal at pH 8.0 and 60 degrees C, and reciprocal plots revealed an apparent K(m) value of 307.7 microM and a V(max) value of 24 733 IU micromol(-1) protein. ReAXE1 also exhibited a capacity to bind to Avicel and H(3)PO(4) acid-swollen cellulose.
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Affiliation(s)
- Shaojun Ding
- Department of Biological Engineering, Nanjing Forestry University, Nanjing, Jiangsu, China.
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Biely P, Mastihubová M, Puchart V. The vicinal hydroxyl group is prerequisite for metal activation of Clostridium thermocellum acetylxylan esterase. Biochim Biophys Acta Gen Subj 2006; 1770:565-70. [PMID: 17261352 DOI: 10.1016/j.bbagen.2006.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 12/05/2006] [Accepted: 12/07/2006] [Indexed: 10/23/2022]
Abstract
Positional specificity of NodB-like domain of a multidomain xylanase U from Clostridium thermocellum (CtAxe) was investigated. Of three monoacetates of 4-nitrophenyl beta-d-xylopyranoside the acetylxylan esterase domain showed a clear preference for the 2-acetate. Moreover, the enzyme was significantly activated by Co(2+). Acetylated methyl beta-d-xylopyranosides were deacetylated slightly better at position 3 than at position 2, suggesting that the enzyme binds the substrate with the small methyl aglycone also in the opposite orientation. Nevertheless, both positions 2 and 3 of methyl beta-d-xylopyranoside were deacetylated much faster in the presence of the activating metal ion. In contrast, replacement of the hydroxyl group at either of these positions with fluorine or hydrogen, as well as acetylation of both positions, abolished the enzyme activity, regardless the absence or the presence of Co(2+). Thus, the presence of the free vicinal hydroxyl group seems to be a prerequisite not only for an efficient deacetylation of position 2 or 3, but also for the activation of the enzyme with cobalt ion. The demonstrated involvement of the vicinal hydroxyl groups in the mechanism of deacetylation is in accord with 3-D structures of CtAxe as well as other CE4 metal-dependent deacetylases.
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Affiliation(s)
- Peter Biely
- Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia
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Ghatora SK, Chadha BS, Saini HS, Bhat MK, Faulds CB. Diversity of plant cell wall esterases in thermophilic and thermotolerant fungi. J Biotechnol 2006; 125:434-45. [PMID: 16713648 DOI: 10.1016/j.jbiotec.2006.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 03/22/2006] [Accepted: 04/03/2006] [Indexed: 11/23/2022]
Abstract
Fourteen thermophilic and thermotolerant fungal strains isolated from composting soils produced plant cell wall-acting esterases in a medium containing corn cobs and oat spelt xylan. The concentrated and dialyzed protein extracts of these fungi were fractionated using isoelectric-focusing, gels sliced and eluted protein in each slice was assayed for esterase activity against p-nitrophenyl acetate. A total of 84 esterases detected on the basis of pI were found to show distinct preferential substrate specificities towards p-nitrophenyl acetate, p-nitrophenyl ferulate and p-nitrophenyl butyrate, and were putatively classified as acetyl esterases and esterases types I and II. None of the esterases were active against p-nitrophenyl myristate. In addition, these esterases were characterized as acid, neutral or alkaline active.
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Affiliation(s)
- Sonia K Ghatora
- Department of Microbiology, Guru Nanak Dev University, Amritsar 143005, India
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18
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Puchart V, Gariépy MC, Shareck F, Dupont C. Identification of catalytically important amino acid residues of Streptomyces lividans acetylxylan esterase A from carbohydrate esterase family 4. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:263-74. [PMID: 16434244 DOI: 10.1016/j.bbapap.2005.11.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Revised: 11/05/2005] [Accepted: 11/21/2005] [Indexed: 11/16/2022]
Abstract
Multiple sequence alignment of Streptomyces lividans acetylxylan esterase A and other carbohydrate esterase family 4 enzymes revealed the following conserved amino acid residues: Asp-12, Asp-13, His-62, His-66, Asp-130, and His-155. These amino acids were mutated in order to investigate a functional role of these residues in catalysis. Replacement of the conserved histidine residues by alanine caused significant reduction of enzymatic activity. Maintenance of ionizable carboxylic group in side chains of amino acids at positions 12, 13, and 130 seems to be necessary for catalytic efficiency. The absence of conserved serine excludes a possibility that the enzyme is a serine esterase, in contrast to acetylxylan esterases of carbohydrate esterase families 1, 5, and 7. On the contrary, total conservation of Asp-12, Asp-13, Asp-130, and His-155 along with dramatic decrease in enzyme activity of mutants of either of these residues lead us to a suggestion that acetylxylan esterase A from Streptomyces lividans and, by inference, other members of carbohydrate esterase family 4 are aspartic deacetylases. We propose that one component of the aspartate dyad/triad functions as a catalytic nucleophile and the other one(s) as a catalytic acid/base. The ester/amide bond cleavage would proceed via a double displacement mechanism through covalently linked acetyl-enzyme intermediate of mixed anhydride type.
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Affiliation(s)
- Vladimír Puchart
- Institut National de la Recherche Scientifique-Institut Armand-Frappier, Université du Québec, 531 boulevard des Prairies, Laval, Québec, Canada H7V 1B7.
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19
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Mastihubová M, Biely P. Deoxy and deoxyfluoro analogues of acetylated methyl beta-D-xylopyranoside--substrates for acetylxylan esterases. Carbohydr Res 2005; 339:2101-10. [PMID: 15280055 DOI: 10.1016/j.carres.2004.06.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2003] [Revised: 06/04/2004] [Accepted: 06/05/2004] [Indexed: 10/26/2022]
Abstract
Four modified substrates for acetylxylan esterases, 2-deoxy, 3-deoxy, 2-deoxy-2-fluoro, and 3-deoxy-3-fluoro derivatives of di-O-acetylated methyl beta-D-xylopyranoside were synthesized via 2,3-anhydropentopyranoside precursors. Methyl 2,3-anhydro-4-O-benzyl-beta-D-ribopyranoside was transformed into methyl 2,3-anhydro-4-O-benzyl-beta-D-lyxopyranoside in three steps. The epoxide ring opening of 2,3-anhydropentopyranosides was accomplished either by hydride reduction or hydrofluorination. Methyl beta-D-xylopyranoside 2,3,4-tri-O-, 2,4-di-O-, and 3,4-di-O-acetates, and the prepared diacetate analogues were tested as substrates of acetylxylan esterases from Schizophyllum commune and Trichoderma reesei. Measurement of their rate of deacetylation pointed to unique structural requirements of the enzymes for the substrates. The enzymes differed particularly in the requirement for the trans vicinal hydroxy group in the deacetylation at C-2 and C-3 and in the tolerance to the presence of trans vicinal acetyl groups esterifying the OH group at C-2 and C-3.
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Affiliation(s)
- Mária Mastihubová
- Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia.
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20
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Kremnický L, Mastihuba V, Côté GL. Trichoderma reesei acetyl esterase catalyzes transesterification in water. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcatb.2004.05.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Mastihubová M, Biely P. Lipase-catalysed preparation of acetates of 4-nitrophenyl β-d-xylopyranoside and their use in kinetic studies of acetyl migration. Carbohydr Res 2004; 339:1353-60. [PMID: 15113674 DOI: 10.1016/j.carres.2004.02.016] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2003] [Revised: 02/16/2004] [Accepted: 02/16/2004] [Indexed: 11/25/2022]
Abstract
Di-O-acetates and mono-O-acetates of 4-nitrophenyl beta-D-xylopyranoside were prepared by use of lipase PS-30. Polarity of organic solvents and reaction time affected the regioselectivity of the di-O-acetylation as well as the yields of monoacetates. The kinetics of acetyl groups migration in these derivatives was studied in aqueous media using HPLC. Migration of the acetyl group strongly depended on pH. The highest rate of acetyl migration was observed from O-2 to O-3 in both 2,4-di-O-acetate and 2-O-acetate. On the contrary, acetyl exchange between O-3 and O-4 in both directions was slower than between O-2 and O-3. The 2,3-di-O-acetate and 4-O-acetate showed to be the most stable towards acetyl migration. The 3,4-di-O-acetate and 4-O-acetate were dominant in the corresponding equilibration mixtures.
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Affiliation(s)
- Mária Mastihubová
- Institute of Chemistry, Slovak Academy of Sciences, SK-845 38 Bratislava, Slovakia.
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22
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Mastihubová M, Mastihuba V, Biely P. An efficient chemoenzymatic route to methyl 4-O-benzyl-2,3-anhydro-β-d-lyxopyranoside from methyl β-d-xylopyranoside. Carbohydr Res 2004; 339:425-8. [PMID: 14698903 DOI: 10.1016/j.carres.2003.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Methyl 4-O-benzyl-2,3-anhydro-beta-D-lyxopyranoside, an intermediate for the preparation of methyl beta-D-xylopyranoside derivatives modified at C-2, was obtained in five steps in 58% yield. The synthetic sequence starts from methyl beta-D-xylopyranoside through two main steps involving regioselective enzymatic acetylation and deacetylation catalyzed by lipase PS.
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Affiliation(s)
- Mária Mastihubová
- Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38, Bratislava, Slovakia
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23
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Biely P, Mastihubová M, Côté GL, Greene RV. Mode of action of acetylxylan esterase from Streptomyces lividans: a study with deoxy and deoxy-fluoro analogues of acetylated methyl beta-D-xylopyranoside. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1622:82-8. [PMID: 12880945 DOI: 10.1016/s0304-4165(03)00130-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Streptomyces lividans acetylxylan esterase removes the 2- or 3-O-acetyl groups from methyl 2,4-di-O-acetyl- and 3,4-di-O-acetyl beta-D-xylopyranoside. When the free hydroxyl group was replaced with a hydrogen or fluorine, the rate of deacetylation was markedly reduced, but regioselectivity was not affected. The regioselectivity of deacetylation was found to be independent of the prevailing conformation of the substrates in solution as determined by 1H-NMR spectroscopy. These observations confirm the importance of the vicinal hydroxyl group and are consistent with our earlier hypothesis that the deacetylation of positions 2 and 3 may involve a common ortho-ester intermediate. Another possible role of the free vicinal hydroxyl group could be the activation of the acyl leaving group in the deacetylation mechanism. Involvement of the free hydroxyl group in the enzyme-substrate binding is not supported by the results of inhibition experiments in which methyl 2,4-di-O-acetyl beta-D-xylopyranoside was used as substrate and its analogues or methyl beta-D-xylopyranoside as inhibitors. The enzyme requires for its efficient action the trans arrangement of the free and acetylated hydroxyl groups at positions 2 and 3.
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Affiliation(s)
- Peter Biely
- Institute of Chemistry, Slovak Academy of Sciences, Dubravska cesta 9, 84238 Bratislava, Slovak Republic.
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Hakulinen N, Tenkanen M, Rouvinen J. Three-dimensional structure of the catalytic core of acetylxylan esterase from Trichoderma reesei: insights into the deacetylation mechanism. J Struct Biol 2000; 132:180-90. [PMID: 11243887 DOI: 10.1006/jsbi.2000.4318] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Acetylxylan esterase from Trichoderma reesei removes acetyl side groups from xylan. The crystal structure of the catalytic core of the enzyme was solved at 1.9 A resolution. The core has an alpha/beta/alpha sandwich fold, similar to that of homologous acetylxylan esterase from Penicillium purpurogenum and cutinase from Fusarium solani. All three enzymes belong to family 5 of the carbohydrate esterases and the superfamily of the alpha/beta hydrolase fold. Evidently, the enzymes have diverged from a common ancestor and they share the same catalytic mechanism. The catalytic machinery of acetylxylan esterase from T. reesei was studied by comparison with cutinase, the catalytic site of which is well known. Acetylxylan esterase is a pure serine esterase having a catalytic triad (Ser90, His187, and Asp175) and an oxyanion hole (Thr13 N, and Thr13 O gamma). Although the catalytic triad of acetylxylan esterase has been reported previously, there has been no mention of the oxyanion hole. A model for the binding of substrates is presented on the basis of the docking of xylose. Acetylxylan esterase from T. reesei is able to deacetylate both mono- and double-acetylated residues, but it is not able to remove acetyl groups located close to large side groups such as 4-O-methylglucuronic acid. If the xylopyranoside residue is double-acetylated, both acetyl groups are removed by the catalytic triad: first one acetyl group is removed and then the residue is reorientated so that the nucleophilic oxygen of serine can attack the second acetyl group.
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Affiliation(s)
- N Hakulinen
- Department of Chemistry, University of Joensuu, FIN-80101 Joensuu, Finland.
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Williamson G, Kroon PA, Faulds CRB. Hairy plant polysaccharides: a close shave with microbial esterases. MICROBIOLOGY (READING, ENGLAND) 1998; 144 ( Pt 8):2011-2023. [PMID: 9720023 DOI: 10.1099/00221287-144-8-2011] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Gary Williamson
- Biochemistry Department, Institute of Food ResearchNorwich Research Park, Colney, Norwich NR4 7UAUK
| | - Paul A Kroon
- Biochemistry Department, Institute of Food ResearchNorwich Research Park, Colney, Norwich NR4 7UAUK
| | - CRaig B Faulds
- Biochemistry Department, Institute of Food ResearchNorwich Research Park, Colney, Norwich NR4 7UAUK
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