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Li N, Zhang R, Zhou J, Huang Z. Structures, Biochemical Characteristics, and Functions of β-Xylosidases. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7961-7976. [PMID: 37192316 DOI: 10.1021/acs.jafc.3c01425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The complete degradation of abundant xylan derived from plants requires the participation of β-xylosidases to produce the xylose which can be converted to xylitol, ethanol, and other valuable chemicals. Some phytochemicals can also be hydrolyzed by β-xylosidases into bioactive substances, such as ginsenosides, 10-deacetyltaxol, cycloastragenol, and anthocyanidins. On the contrary, some hydroxyl-containing substances such as alcohols, sugars, and phenols can be xylosylated by β-xylosidases into new chemicals such as alkyl xylosides, oligosaccharides, and xylosylated phenols. Thus, β-xylosidases shows great application prospects in food, brewing, and pharmaceutical industries. This review focuses on the molecular structures, biochemical properties, and bioactive substance transformation function of β-xylosidases derived from bacteria, fungi, actinomycetes, and metagenomes. The molecular mechanisms of β-xylosidases related to the properties and functions are also discussed. This review will serve as a reference for the engineering and application of β-xylosidases in food, brewing, and pharmaceutical industries.
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Affiliation(s)
- Na Li
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Rui Zhang
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Junpei Zhou
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
| | - Zunxi Huang
- Engineering Research Center of Sustainable Development and Utilization of Biomass Energy, Ministry of Education, Yunnan Normal University, Kunming 650500, People's Republic of China
- College of Life Sciences, Yunnan Normal University, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan for Biomass Energy and Biotechnology of Environment, Kunming 650500, People's Republic of China
- Key Laboratory of Yunnan Provincial Education Department for Plateau Characteristic Food Enzymes, Kunming 650500, People's Republic of China
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Teramoto K, Tsutsui S, Sato T, Fujimoto Z, Kaneko S. Substrate Specificities of GH8, GH39, and GH52 β-xylosidases from Bacillus halodurans C-125 Toward Substituted Xylooligosaccharides. Appl Biochem Biotechnol 2021; 193:1042-1055. [PMID: 33394289 DOI: 10.1007/s12010-020-03451-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/08/2020] [Indexed: 11/30/2022]
Abstract
Substrate specificities of glycoside hydrolase families 8 (Rex), 39 (BhXyl39), and 52 (BhXyl52) β-xylosidases from Bacillus halodurans C-125 were investigated. BhXyl39 hydrolyzed xylotriose most efficiently among the linear xylooligosaccharides. The activity decreased in the order of xylohexaose > xylopentaose > xylotetraose and it had little effect on xylobiose. In contrast, BhXyl52 hydrolyzed xylobiose and xylotriose most efficiently, and its activity decreased when the main chain became longer as follows: xylotetraose > xylopentaose > xylohexaose. Rex produced O-β-D-xylopyranosyl-(1 → 4)-[O-α-L-arabinofuranosyl-(1 → 3)]-O-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranose (Ara2Xyl3) and O-β-D-xylopyranosyl-(1 → 4)-[O-4-O-methyl-α-D-glucuronopyranosyl-(l → 2)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranose (MeGlcA2Xyl3), which lost a xylose residue from the reducing end of O-β-D-xylopyranosyl-(1 → 4)-[O-α-L-arabinofuranosyl-(1 → 3)]-O-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranose (Ara3Xyl4) and O-β-D-xylopyranosyl-(1 → 4)-[O-4-O-methyl-α-D-glucuronopyranosyl-(1 → 2)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranose (MeGlcA3Xyl4). It was considered that there is no space to accommodate side chains at subsite -1. BhXyl39 rapidly hydrolyzes the non-reducing-end xylose linkages of MeGlcA3Xyl4, while the arabinose branch does not significantly affect the enzyme activity because it degrades Ara3Xyl4 as rapidly as unmodified xylotetraose. The model structure suggested that BhXyl39 enhanced the activity for MeGlcA3Xyl4 by forming a hydrogen bond between glucuronic acid and Lys265. BhXyl52 did not hydrolyze Ara3Xyl4 and MeGlcA3Xyl4 because it has a narrow substrate binding pocket and 2- and 3-hydroxyl groups of xylose at subsite +1 hydrogen bond to the enzyme.
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Affiliation(s)
- Koji Teramoto
- Department of Subtropical Biochemistry and Biotechnology, Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan
| | - Sosyu Tsutsui
- Department of Subtropical Biochemistry and Biotechnology, Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan.,The United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan
| | - Tomoko Sato
- Advanced Analysis Center, National Agriculture and Food Research Organization (NARO), 2-1-2 Kannondai, Tsukuba, 305-8602, Japan
| | - Zui Fujimoto
- Advanced Analysis Center, National Agriculture and Food Research Organization (NARO), 2-1-2 Kannondai, Tsukuba, 305-8602, Japan
| | - Satoshi Kaneko
- Department of Subtropical Biochemistry and Biotechnology, Faculty of Agriculture, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa, 903-0213, Japan. .,The United Graduate School of Agricultural Sciences, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan.
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Bioprospection of Enzymes and Microorganisms in Insects to Improve Second-Generation Ethanol Production. Ind Biotechnol (New Rochelle N Y) 2019. [DOI: 10.1089/ind.2019.0019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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A novel β-xylosidase from Anoxybacillus sp. 3M towards an improved agro-industrial residues saccharification. Int J Biol Macromol 2019; 122:1224-1234. [DOI: 10.1016/j.ijbiomac.2018.09.075] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 11/20/2022]
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Mustafa G, Kousar S, Rajoka MI, Jamil A. Molecular cloning and comparative sequence analysis of fungal β-Xylosidases. AMB Express 2016; 6:30. [PMID: 27080227 PMCID: PMC5471287 DOI: 10.1186/s13568-016-0202-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 04/06/2016] [Indexed: 01/21/2023] Open
Abstract
Commercial scale degradation of hemicelluloses into easily accessible sugar residues is practically crucial in industrial as well as biochemical processes. Xylanolytic enzymes have a great number of possible applications in many biotechnological processes and therefore, these enzymes are continuously attracting the attention of scientists. Due to this fact, different β-Xylosidases have been isolated, purified and characterized from several bacteria and fungi. Microorganisms in this respect have gained much momentum for production of these significant biocatalysts with remarkable features. It is difficult to propagate microorganisms for efficient and cost-competitive production of β-Xylosidase from hemicelluloses due to expensive conditions of fermentation. The screening of new organisms with an enhanced production of β-Xylosidases has been made possible with the help of recombinant DNA technology. β-Xylosidase genes haven been cloned and expressed on large scale in both homologous and heterologous hosts with the advent of genetic engineering. Therefore, we have reviewed the literature regarding cloning of β-Xylosidase genes into various hosts for their heterologous production along with sequence similarities among different β-Xylosidases. The study provides insight into the current status of cloning, expression and sequence analysis of β-Xylosidases for industrial applications.
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Zhang S, Wang H, Shi P, Xu B, Bai Y, Luo H, Yao B. Cloning, expression, and characterization of a thermostable β-xylosidase from thermoacidophilic Alicyclobacillus sp. A4. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.05.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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GH52 xylosidase from Geobacillus stearothermophilus: characterization and introduction of xylanase activity by site‑directed mutagenesis of Tyr509. J Ind Microbiol Biotechnol 2014; 41:65-74. [PMID: 24122394 DOI: 10.1007/s10295-013-1351-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
Abstract
A xylosidase gene, gsxyn, was cloned from the deep-sea thermophilic Geobacillus stearothermophilus, which consisted of 2,118 bp and encoded a protein of 705 amino acids with a calculated molecular mass of 79.8 kDa. The GSxyn of glycoside hydrolase family 52 (GH52) displayed its maximum activity at 70 °C and pH 5.5. The K m and k cat values of GSxyn for ρNPX were 0.48 mM and 36.64 s−1, respectively. Interestingly, a new exo-xylanase activity was introduced into GSxyn by mutating the tyrosine509 into glutamic acid, whereas the resultant enzyme variant, Y509E, retained the xylosidase activity. The optimum xylanase activity of theY509E mutant displayed at pH 6.5 and 50 °C, and retained approximately 45 % of its maximal activity at 55 °C, pH 6.5 for 60 min. The K m and k cat values of the xylanase activity of Y509E mutant for beechwood xylan were 5.10 mg/ml and 22.53 s−1, respectively. The optimum xylosidase activity of theY509E mutant displayed at pH 5.5 and 60 °C. The K m and k cat values of the xylosidase activity of Y509E mutant for ρNPX were 0.51 mM and 22.53 s−1, respectively. This report demonstrated that GH52 xylosidase has provided a platform for generating bifunctional enzymes for industrially significant and complex substrates, such as plant cell wall.
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β-xylosidases and α-L-arabinofuranosidases: accessory enzymes for arabinoxylan degradation. Biotechnol Adv 2013; 32:316-32. [PMID: 24239877 DOI: 10.1016/j.biotechadv.2013.11.005] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/28/2013] [Accepted: 11/09/2013] [Indexed: 11/22/2022]
Abstract
Arabinoxylan (AX) is among the most abundant hemicelluloses on earth and one of the major components of feedstocks that are currently investigated as a source for advanced biofuels. As global research into these sustainable biofuels is increasing, scientific knowledge about the enzymatic breakdown of AX advanced significantly over the last decade. This review focuses on the exo-acting AX hydrolases, such as α-arabinofuranosidases and β-xylosidases. It aims to provide a comprehensive overview of the diverse substrate specificities and corresponding structural features found in the different glycoside hydrolase families. A careful review of the available literature reveals a marked difference in activity between synthetically labeled and naturally occurring substrates, often leading to erroneous enzymatic annotations. Therefore, special attention is given to enzymes with experimental evidence on the hydrolysis of natural polymers.
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Anand A, Kumar V, Satyanarayana T. Characteristics of thermostable endoxylanase and β-xylosidase of the extremely thermophilic bacterium Geobacillus thermodenitrificans TSAA1 and its applicability in generating xylooligosaccharides and xylose from agro-residues. Extremophiles 2013; 17:357-66. [DOI: 10.1007/s00792-013-0524-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 01/31/2013] [Indexed: 10/27/2022]
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Abstract
α-Glucuronidase enzymes play an essential role in the full enzymatic hydrolysis of hemicellulose. Up to this point, all genes encoding α-glucuronidase enzymes have been cloned from individual, pure culture strains. Using a high-throughput screening strategy, we have isolated the first α-glucuronidase gene (rum630-AG) from a mixed population of microorganisms. The gene was subcloned into a prokaryotic vector, and the enzyme was overexpressed and biochemically characterized. The RUM630-AG enzyme had optimum activity at pH 6.5 and 40 °C. When birchwood xylan was used as substrate, the RUM630-AG functioned synergistically with an endoxylanase enzyme to hydrolyze the substrate.
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Lee CC, Wagschal K, Kibblewhite-Accinelli RE, Orts WJ, Robertson GH, Wong DWS. An α-Glucuronidase Enzyme Activity Assay Adaptable for Solid Phase Screening. Appl Biochem Biotechnol 2008; 155:314-20. [DOI: 10.1007/s12010-008-8408-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 10/22/2008] [Indexed: 11/28/2022]
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The family 52 beta-xylosidase from Geobacillus stearothermophilus is a dimer: structural and biophysical characterization of a glycoside hydrolase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2008; 1784:1924-34. [PMID: 18657634 DOI: 10.1016/j.bbapap.2008.06.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 06/24/2008] [Accepted: 06/25/2008] [Indexed: 11/22/2022]
Abstract
Xylans are the most abundant polysaccharides forming the plant cell wall hemicelluloses, and they are degraded, among other proteins, by beta-xylosidase enzymes. In this work, the structural and biophysical properties of the family 52 beta-xylosidase from Geobacillus stearothermophilus, XynB2, are described. Size exclusion chromatography, analytical centrifugation, ITC, CD, fluorescence (steady state and ANS-binding) and FTIR were used to obtain the structure, the oligomerization state and the conformational changes of XynB2, as pH, chemical denaturants or temperature were modified. This report describes the first extensive conformational characterization of a family 52 beta-xylosidase. The active protein was a highly hydrated dimer, whose active site was formed by the two protomers, and it probably involved aromatic residues. At low pH, the protein was not active and it populated a monomeric molten-globule-like species, which had a conformational transition with a pK(a) of approximately 4.0. Thermal and chemical-denaturations of the native protein showed hysteresis behaviour. The protein at physiological pH was formed by alpha-helix (30%) and beta-sheet (30%), as shown by CD and FTIR. Comparison with other xylosidases of the same family indicates that the percentages of secondary structure seem to be conserved among the members of the family.
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Quintero D, Velasco Z, Hurtado-Gómez E, Neira JL, Contreras LM. Isolation and characterization of a thermostable β-xylosidase in the thermophilic bacterium Geobacillus pallidus. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:510-8. [PMID: 17363348 DOI: 10.1016/j.bbapap.2007.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2006] [Revised: 02/01/2007] [Accepted: 02/06/2007] [Indexed: 11/26/2022]
Abstract
The isolation, purification, biochemical and biophysical characterization of the first reported beta-xylosidase from Geobacillus pallidus are described. The protein has an optimum pH close to 8 and an optimum temperature of 70 degrees C. These biochemical properties agree with those obtained by spectroscopic techniques, namely, circular dichroism (CD), infrared (FTIR) and fluorescence measurements. Thermal denaturation, followed by CD and FTIR, showed an apparent thermal denaturation midpoint close to 80 degrees C. The protein was probably a hydrated trimer in solution with, an elongated shape, as shown by gel filtration experiments. FTIR deconvolution spectra indicated that the protein contains a high percentage of alpha-helix (44%) and beta-sheet (40%). The sequencing of the N terminus and the biochemical features indicate that this new member of beta-xylosidases belongs to the GH52 family. Since there are no reported structural studies of any member of this family, our studies provide the first clue for the full conformational characterization of this protein family.
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Affiliation(s)
- Denny Quintero
- Departamento de Biología, Facultad Experimental de Ciencias y Tecnología, Universidad de Carabobo, Valencia, Venezuela
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Smaali I, Rémond C, O'Donohue MJ. Expression in Escherichia coli and characterization of β-xylosidases GH39 and GH-43 from Bacillus halodurans C-125. Appl Microbiol Biotechnol 2006; 73:582-90. [PMID: 16896606 DOI: 10.1007/s00253-006-0512-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Revised: 05/17/2006] [Accepted: 05/17/2006] [Indexed: 10/24/2022]
Abstract
To develop xylosidases as tools for the hydrolysis of wheat bran arabinoxylans, two beta-xylosidases from Bacillus halodurans C-125 have been cloned and expressed in Escherichia coli. The recombinant (His)(6)-tagged enzymes, designated as XylBH39 and XylBH43, were efficiently purified using Ni(2+)-affinity chromatography. Determination of native molecular masses indicated that XylBH43 is dimeric in solution, whereas a similar analysis of XylBH39 did not allow differentiation between the dimeric and trimeric states. Both enzymes had similar pH and temperature optima (pH 7.5 and 55 degrees C for XylBH39 and pH 8 and 60 degrees C for XylBH43) and were relatively stable over the pH range of 3.5-8.5. In contrast, XylBH39 was more thermostable. At 60 degrees C, XylBH39 and XylBH43 displayed approximate half-life values of 2.40 and 0.05 h, respectively. The comparison of the ratio k (cat)/K (M) revealed that XylBH43 hydrolyzed p-nitrophenyl-beta-D: -xyloside more efficiently (4.6-fold) than XylBH39. Similarly, while XylBH43 was 18-fold less active on p-nitrophenyl-alpha-L: -arabinofuranoside, XylBH39 was essentially inactive on this substrate. Using either p-nitrophenyl-beta-D: -xyloside or xylotriose, XylBH39 performed transglycosylation, while xylobiose proved to be a poor substrate for both hydrolysis and transglycosylation. The use of XylBH39 and XylBH43 for the posttreatment of endoxylanase-generated wheat bran hydrolysates revealed that XylBH43 efficiently produced xylose monomers (385 microg/ml after 330 min incubation). Its activity was improved by the simultaneous deployment of an alpha-L: -arabinofuranosidase. Together, these enzymes were able to release 521 microg/ml of xylose after 330 min. This constitutes an approximate yield improvement of 35%.
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Affiliation(s)
- Issam Smaali
- Institut National de la Recherche Agronomique, UMR 614, 8 rue Gabriel Voisin, B.P. 316, 51688 Reims, Cedex 2, France
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LIU CHENJIAN, SUZUKI TOHRU, HIRATA SATORU, KAWAI KEIICHI. The Processing of High-Molecular-Weight Xylanase (XynE, 110 kDa) from Aeromonas caviae ME-1 to 60-kDa Xylanase (XynE60) in Escherichia coli and Purification and Characterization of XynE60. J Biosci Bioeng 2003. [DOI: 10.1263/jbb.95.95] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Liu CJ, Suzuki T, Hirata S, Kawai K. The processing of high-molecular-weight xylanase (XynE, 110 kDa) fromAeromonas caviae ME-1 to 60-kDa xylanase (XynE60) inEscherichia coli and purification and characterization of XynE60. J Biosci Bioeng 2003; 95:95-101. [PMID: 16233373 DOI: 10.1016/s1389-1723(03)80155-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2002] [Accepted: 09/30/2002] [Indexed: 10/27/2022]
Abstract
A xylanase gene (xynE) encoding XynE (110 kDa) was cloned from a lambda phage genomic library of Aeromonas caviae ME-1 which is a multiple-xylanase-producing bacterium. Upon nucleotide sequence analysis, we found that xynE comprises 2823 by and encodes a protein of 941 amino acid residues (104,153 Da), which was similar to endo-beta-1,4-xylanases which are categorized to glycosyl hydrolase family 10. An Escherichia coli transformant that harbored pXED30 carrying xynE produced 110-, 84-, 72-, and 66-kDa xylanases in the cell-free extract, and 72- and 66-kDa xylanases in the culture supernatant. We purified the 66-kDa xylanase to electrophoretic homogeneity from a culture supernatant by a series of column chromatographies. The calculated molecular mass of the purified xylanase determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was 60,154.50 Da, and the xylanase was designated XynE60. Analysis of the N-terminal 10 amino acid residues and the determined molecular mass of XynE60 revealed that XynE60 is a product processed at the Gly26-Gly27, and Thr565-Ala566 sites of XynE by proteolytic cleavage. XynE60 showed optimal activity at 55 degrees C and pH 8.0, and was stable below 45 degrees C and at pH 7.0-8.5. The K(m) and V(max) of XynE60 were calculated to be 8.1 mg/ml and 6897 nkat/mg, respectively.
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Affiliation(s)
- Chen Jian Liu
- United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
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Liu CJ, Suzuki T, Hirata S, Kawai K. Processing of XynE (110-kDa) ofAeromonas caviae ME-1 to 72-kDa xylanase inEscherichia coli transformant. J Biosci Bioeng 2003; 96:406-8. [PMID: 16233547 DOI: 10.1016/s1389-1723(03)90147-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Accepted: 07/16/2003] [Indexed: 11/25/2022]
Abstract
An extracellular 72-kDa xylanase from an Escherichia coli transformant that harbored pXED30 carrying xynE of Aeromonas caviae ME-1 was purified by extraction following SDS-PAGE to electrophoretic homogeneity. The analysis of N-terminal 10 amino acid residues (Gly-Ala-Arg-Ala-Gln-Ala-Ala-Ala-Asp-Val) revealed a 72-kDa product derived by the cleavage of Gly26-Gly27 at the N-terminal region of 110 kDa XynE. The 72-kDa xylanase from A. caviae ME-1 was found to have the same sequence as that of the N-terminal 10 amino acid residues. When OmpT-deficient E. coli mutants were used as hosts, the 72-kDa xylanase was detected in cell-free extracts, but not in the culture supernatant, suggesting that OmpT is not involved in the cleavage at the C-terminal region, but is involved in the secretion of 72-kDa xylanase to the culture medium.
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Affiliation(s)
- Chen Jian Liu
- United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan
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