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Zhu W, Qin L, Xu Y, Lu H, Wu Q, Li W, Zhang C, Li X. Three Molecular Modification Strategies to Improve the Thermostability of Xylanase XynA from Streptomyces rameus L2001. Foods 2023; 12:foods12040879. [PMID: 36832954 PMCID: PMC9957083 DOI: 10.3390/foods12040879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/07/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Glycoside hydrolase family 11 (GH11) xylanases are the preferred candidates for the production of functional oligosaccharides. However, the low thermostability of natural GH11 xylanases limits their industrial applications. In this study, we investigated the following three strategies to modify the thermostability of xylanase XynA from Streptomyces rameus L2001 mutation to reduce surface entropy, intramolecular disulfide bond construction, and molecular cyclization. Changes in the thermostability of XynA mutants were analyzed using molecular simulations. All mutants showed improved thermostability and catalytic efficiency compared with XynA, except for molecular cyclization. The residual activities of high-entropy amino acid-replacement mutants Q24A and K104A increased from 18.70% to more than 41.23% when kept at 65 °C for 30 min. The catalytic efficiencies of Q24A and K143A increased to 129.99 and 92.26 mL/s/mg, respectively, compared with XynA (62.97 mL/s/mg) when using beechwood xylan as the substrate. The mutant enzyme with disulfide bonds formed between Val3 and Thr30 increased the t1/260 °C by 13.33-fold and the catalytic efficiency by 1.80-fold compared with the wild-type XynA. The high thermostabilities and hydrolytic activities of XynA mutants will be useful for enzymatic production of functional xylo-oligosaccharides.
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Affiliation(s)
- Weijia Zhu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Liqin Qin
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Youqiang Xu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Hongyun Lu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Qiuhua Wu
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
| | - Weiwei Li
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 100048, China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing 100048, China
| | - Chengnan Zhang
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 100048, China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing 100048, China
| | - Xiuting Li
- School of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China
- Key Laboratory of Brewing Microbiome and Enzymatic Molecular Engineering, China General Chamber of Commerce, Beijing 100048, China
- Key Laboratory of Brewing Molecular Engineering of China Light Industry, Beijing Technology and Business University, Beijing 100048, China
- Correspondence:
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2
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Cayetano-Cruz M, Caro-Gómez LA, Plascencia-Espinosa M, Santiago-Hernández A, Benítez-Cardoza CG, Campos JE, Hidalgo-Lara ME, Zamorano-Carrillo A. Effect of the single mutation N9Y on the catalytical properties of xylanase Xyn11A from Cellulomonas uda: a biochemical and molecular dynamic simulation analysis. Biosci Biotechnol Biochem 2021; 85:1971-1985. [PMID: 34232281 DOI: 10.1093/bbb/zbab124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Accepted: 06/29/2021] [Indexed: 11/12/2022]
Abstract
Cellulomonas uda produces Xyn11A, moderately thermostable xylanase, with optimal activity at 50 °C and pH 6.5. An improvement in the biochemical properties of Xyn11A was achieved by site-directed mutagenesis approach. Wild-type xylanase, Xyn11A-WT, and its mutant Xyn11A-N9Y were expressed in Escherichia coli, and then both enzymes were purified and characterized. Xyn11A-N9Y displayed optimal activity at 60 °C and pH 7.5, an upward shift of 10 ºC in the optimum temperature, and an upward shift of one unit in optimum pH; also, it manifested an 11-fold increase in thermal stability at 60 ºC, compared to that displayed by Xyn11A-WT. Molecular dynamics (MD) simulations of Xyn11A-WT and Xyn11A-N9Y suggest the substitution N9Y leads to an array of secondary structure changes at the N-terminal end and an increase in the number of hydrogen bonds in Xyn11A-N9Y. Based on the significant improvements, Xyn11A-N9Y may be considered as a candidate for several biotechnological applications.
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Affiliation(s)
- Maribel Cayetano-Cruz
- Departamento de Biotecnología y Bioingeniería, CINVESTAV, Av. Instituto Politécnico Nacional No. 2508, D.F. CP 07360, México
| | - Luis A Caro-Gómez
- Laboratorio de Investigación Bioquímica y Biofísica Computacional, Doctorado en Ciencias en Biotecnología, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, México, D.F. 07320, México
| | - Miguel Plascencia-Espinosa
- CIBA-Instituto Politécnico Nacional, Km 1.5 Carretera Estatal Tecuexcomac-Tepetitla, 90700, Tepetitla, Tlaxcala, México
| | - Alejandro Santiago-Hernández
- Departamento de Biotecnología y Bioingeniería, CINVESTAV, Av. Instituto Politécnico Nacional No. 2508, D.F. CP 07360, México
| | - Claudia G Benítez-Cardoza
- Laboratorio de Investigación Bioquímica y Biofísica Computacional, Doctorado en Ciencias en Biotecnología, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, México, D.F. 07320, México
| | - Jorge E Campos
- Laboratorio de Bioquímica Molecular, UBIPRO, FES Iztacala, UNAM, Av. de los Barrios No. 1, Los Reyes Iztacala, CP 54090, Tlalnepantla de Baz, Estado de México, México
| | - María Eugenia Hidalgo-Lara
- Departamento de Biotecnología y Bioingeniería, CINVESTAV, Av. Instituto Politécnico Nacional No. 2508, D.F. CP 07360, México
| | - Absalom Zamorano-Carrillo
- Laboratorio de Investigación Bioquímica y Biofísica Computacional, Doctorado en Ciencias en Biotecnología, ENMH, Instituto Politécnico Nacional, Guillermo Massieu Helguera, México, D.F. 07320, México
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3
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Impact of the disulfide bond on hydrolytic characteristics of a xylanase from Talaromyces thermophiles F1208. Int J Biol Macromol 2020; 164:1748-1757. [DOI: 10.1016/j.ijbiomac.2020.07.270] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 07/20/2020] [Indexed: 01/04/2023]
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4
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In silico Approach to Elucidate Factors Associated with GH1 β-Glucosidase Thermostability. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2019. [DOI: 10.22207/jpam.13.4.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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5
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Synergistic effects between the additions of a disulphide bridge and an N-terminal hydrophobic sidechain on the binding pocket tilting and enhanced Xyn11A activity. Arch Biochem Biophys 2019; 672:108068. [DOI: 10.1016/j.abb.2019.108068] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/20/2019] [Accepted: 08/07/2019] [Indexed: 11/22/2022]
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6
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Xiong K, Hou J, Jiang Y, Li X, Teng C, Li Q, Fan G, Yang R, Zhang C. Mutagenesis of N-terminal residues confer thermostability on a Penicillium janthinellum MA21601 xylanase. BMC Biotechnol 2019; 19:51. [PMID: 31345213 PMCID: PMC6659274 DOI: 10.1186/s12896-019-0541-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/05/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A mesophilic xylanase PjxA from Penicillium janthinellum MA21601 has high specific activity under acidic condition and holds great potential for applications in the animal feed industry. To enhance the thermostability of xylanase PjxA, two mutation strategies in the N-terminal region were examined and then integrated into the xylanase to further improvement. The recombinant xylanase PTxA-DB (The meaning of DB is disulfide-bridge.) was constructed by replacement of five residues in the mutated region in TfxA (T10Y, N11H, N12D, Y15F, N30 L), combined with an additional disulfide bridge in the N-terminal region. RESULTS The Tm value of mutant PTxA-DB was improved from 21.3 °C to 76.6 °C, and its half-life was found to be 53.6 min at 60 °C, 107-fold higher than the wild type strain. The location of the disulfide bridge (T2C-T29C) was between the irregular loop and the β-strand A2, accounting for most of the improvement in thermostability of PjxA. Further analysis indicated T2C, T29C, N30 L and Y15F lead to increase N-terminal hydrophobicity. Moreover, the specific activity and substrate affinity of PTxA-DB were also enhanced under the acidic pH values. CONCLUSIONS These results indicated PTxA-DB could be a prospective additive to industrial animal feeds.
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Affiliation(s)
- Ke Xiong
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China
| | - Jie Hou
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China
| | - Yuefeng Jiang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China
| | - Xiuting Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China. .,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China. .,Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.
| | - Chao Teng
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China
| | - Qin Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China
| | - Guangsen Fan
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,School of Food and Chemical Engineering, Beijing Technology and Business University, Beijing, 100048, China
| | - Ran Yang
- Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,School of Food and Chemical Engineering, Beijing Technology and Business University, Beijing, 100048, China
| | - Chengnan Zhang
- Beijing Engineering and Technology Research Center of Food Additives, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,Beijing Key Laboratory of Flavor Chemistry, Beijing Technology and Business University, No 11 Fucheng Street, Haidian District, Beijing, 100084, China.,School of Food and Chemical Engineering, Beijing Technology and Business University, Beijing, 100048, China
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7
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He J, Tang F, Chen D, Yu B, Luo Y, Zheng P, Mao X, Yu J, Yu F. Design, expression and functional characterization of a thermostable xylanase from Trichoderma reesei. PLoS One 2019; 14:e0210548. [PMID: 30650138 PMCID: PMC6334952 DOI: 10.1371/journal.pone.0210548] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 12/27/2018] [Indexed: 11/19/2022] Open
Abstract
Xylanases isolated from microorganisms such as the Trichoderma reesei have attracted considerable research interest because of their potential in various industrial applications. However, naturally isolated xylanases cannot withstand harsh conditions such as high temperature and basic pH. In this study, we performed structural analysis of the major T. reesei xylanase (Xyn2), and novel flexible regions of the enzyme were identified based on B-factor, a molecular dynamics (MD) parameter. To improve thermostability of the Xyn2, disulfide bonds were introduced into the unstable flexible region by using site-directed mutagenesis and two recombinant xylanases, XM1 (Xyn2Cys12-52) and XM2 (Xyn2Cys59-149) were successfully expressed in Pichia pastoris. Secreted recombinant Xyn2 was estimated by SDS-PAGE to be 24 kDa. Interestingly, the half-lives of XM1 and XM2 at 60°C were 2.5- and 1.8- fold higher, respectively than those of native Xyn2. The XM1 also exhibited improved pH stability and maintained more than 60% activity over pH values ranging from 2.0 to 10.0. However, the specific activity and catalytic efficiency of XM1 was decreased as compared to those of XM2 and native Xyn2. Our results will assist not only in elucidating of the interactions between protein structure and function, but also in rational target selection for improving the thermostability of enzymes.
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Affiliation(s)
- Jun He
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
- * E-mail:
| | - Feng Tang
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Daiwen Chen
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Bing Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Yuheng Luo
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Ping Zheng
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Xiangbing Mao
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Jie Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
| | - Feng Yu
- Institute of Animal Nutrition, Sichuan Agricultural University, Chengdu, Sichuan, P. R. China
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8
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Effect of disulfide bridge on hydrolytic characteristics of xylanase from Penicillium janthinellum. Int J Biol Macromol 2018; 120:405-413. [PMID: 30145159 DOI: 10.1016/j.ijbiomac.2018.08.099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/02/2018] [Accepted: 08/21/2018] [Indexed: 11/20/2022]
Abstract
Highly efficient and stable enzymes are required for application in biotechnology, to meet the technical, environmental, and economic industrial demands. Xylanases are hemicellulolytic enzymes that degrade the heteroxylan constituent of the lignocellulosic plant cell wall. In this study, an acidic xylanase designated Pjxyn (pH 4.0) from Penicillium janthinellum was engineered by the introduction of a disulfide bridge. This strategy exploited the influence of the bridge on hydrolysis characteristics and enhanced hydrolysis was achieved. Three mutants [PjxynS(27)S(39), PjxynS(27)S(186), and PjxynS(39)S(186)] produced more xylose and xylobiose as hydrolysis products compared with the wild-type Pjxyn, when commercial xylans and lab-prepared water-insoluble corncob-xylan were used as the substrates, especial for the PjxynS(27)S(39) mutant, the content of xylose and xylobiose was 87.62% (using beechwood xylan) and 69.91% (using oat-spelt xylan) higher than that in the hydrolysis products of Pjxyn. Moreover, each mutant combined with the xylanase mutant T-XynFM effectively decreased the production of xylose with an optimum xylobiose yield. The findings demonstrate the potential industrial value of engineering xylanase to improve its hydrolytic properties and thermostability.
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9
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Engineering and introduction of de novo disulphide bridges in organophosphorus hydrolase enzyme for thermostability improvement. J Biosci 2017; 41:577-588. [PMID: 27966481 DOI: 10.1007/s12038-016-9643-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The organophosphorus hydrolase (OPH) has been used to degrade organophosphorus chemicals, as one of the most frequently used decontamination methods. Under chemical and thermal denaturing conditions, the enzyme has been shown to unfold. To utilize this enzyme in various applications, the thermal stability is of importance. The engineering of de novo disulphide bridges has been explored as a means to increase the thermal stability of enzymes in the rational method of protein engineering. In this study, Disulphide by Design software, homology modelling and molecular dynamics simulations were used to select appropriate amino acid pairs for the introduction of disulphide bridge to improve protein thermostability. The thermostability of the wild-type and three selected mutant enzymes were evaluated by half-life, delta G inactivation (ΔGi) and structural studies (fluorescence and far-UV CD analysis). Data analysis showed that half-life of A204C/T234C and T128C/E153C mutants were increased up to 4 and 24 min, respectively; however, for the G74C/A78C mutant, the half-life was decreased up to 9 min. For the T128C/E124C mutant, both thermal stability and Catalytic efficiency (kcat) were also increased. The half-life and ΔGi results were correlated to the obtained information from structural studies by circular dichroism (CD) spectrometry and extrinsic fluorescence experiments; as rigidity increased in A204C/T2234C and T128C/E153C mutants, half-life and ΔGi also increased. For G74C/A78C mutant, these parameters decreased due to its higher flexibility. The results were submitted a strong evidence for the possibility to improve the thermostability of OPH enzyme by introducing a disulphide bridge after bioinformatics design, even though this design would not be always successful.
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10
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Tang F, Chen D, Yu B, Luo Y, Zheng P, Mao X, Yu J, He J. Improving the thermostability of Trichoderma reesei xylanase 2 by introducing disulfide bonds. ELECTRON J BIOTECHN 2017. [DOI: 10.1016/j.ejbt.2017.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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11
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Ergün BG, Çalık P. Lignocellulose degrading extremozymes produced by Pichia pastoris: current status and future prospects. Bioprocess Biosyst Eng 2016; 39:1-36. [PMID: 26497303 DOI: 10.1007/s00449-015-1476-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/21/2015] [Indexed: 02/06/2023]
Abstract
In this review article, extremophilic lignocellulosic enzymes with special interest on xylanases, β-mannanases, laccases and finally cellulases, namely, endoglucanases, exoglucanases and β-glucosidases produced by Pichia pastoris are reviewed for the first time. Recombinant lignocellulosic extremozymes are discussed from the perspectives of their potential application areas; characteristics of recombinant and native enzymes; the effects of P. pastoris expression system on recombinant extremozymes; and their expression levels and applied strategies to increase the enzyme expression yield. Further, effects of enzyme domains on activity and stability, protein engineering via molecular dynamics simulation and computational prediction, and site-directed mutagenesis and amino acid modifications done are also focused. Superior enzyme characteristics and improved stability due to the proper post-translational modifications and better protein folding performed by P. pastoris make this host favourable for extremozyme production. Especially, glycosylation contributes to the structure, function and stability of enzymes, as generally glycosylated enzymes produced by P. pastoris exhibit better thermostability than non-glycosylated enzymes. However, there has been limited study on enzyme engineering to improve catalytic efficiency and stability of lignocellulosic enzymes. Thus, in the future, studies should focus on protein engineering to improve stability and catalytic efficiency via computational modelling, mutations, domain replacements and fusion enzyme technology. Also metagenomic data need to be used more extensively to produce novel enzymes with extreme characteristics and stability.
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12
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Improvement in the thermostability of chitosanase from Bacillus ehimensis by introducing artificial disulfide bonds. Biotechnol Lett 2016; 38:1809-15. [DOI: 10.1007/s10529-016-2168-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 06/21/2016] [Indexed: 01/08/2023]
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13
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Li YY, Zhong KX, Hu AH, Liu DN, Chen LZ, Xu SD. High-level expression and characterization of a thermostable xylanase mutant from Trichoderma reesei in Pichia pastoris. Protein Expr Purif 2014; 108:90-96. [PMID: 25434687 DOI: 10.1016/j.pep.2014.11.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
Abstract
A gene encoding xylanase 2 mutant from Trichoderma reesei (T2C/T28C, named mxyn2) was cloned into the Pichia pastoris X33 strain using the vector pPICZαA. Recombinant Mxyn2p was functionally expressed in P. pastoris X33 and secreted into the supernatant. Real time qPCR demonstrated that an increase in gene copy number correlated with higher levels of expression. Supernatant from methanol induced cells was concentrated by ultrafiltration with a 10kDa cut off membrane, and purified with ion exchange chromatography using SP Sepharose Fast Flow chromatography. Recombinant Mxyn2p protein had the highest activity at 75°C, while recombinant protein encoded by the "wild type" xylanase gene xyn2, also expressed in Pichia, was 20°C lower. The Mxyn2p enzyme retained more than 70% of its activity after incubation at 80°C for 10min. The effects of the optimal pH and temperature for higher expression levels in P. pastoris were also determined, 6.0 and 22°C, respectively. The maximum xylanase activity of Mxyn2p was 13,000nkat/mg (9.88g/l) in fed-batch cultivation after 168h induction with methanol in a 50l bioreactor.
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Affiliation(s)
- Yang-Yuan Li
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China.
| | - Kai-Xin Zhong
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China
| | - Ai-Hong Hu
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China
| | - Dan-Ni Liu
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China
| | - Li-Zhi Chen
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China
| | - Shu-de Xu
- Guangdong VTR Bio-Tech Co., Ltd., Zhuhai 519060, Guangdong, China; Guangdong Feed Additive Research and Development Center, Zhuhai 519060, Guangdong, China
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14
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Shen T, Guo Z, Ji C. Structure of a His170Tyr mutant of thermostable pNPPase from Geobacillus stearothermophilus. Acta Crystallogr F Struct Biol Commun 2014; 70:697-702. [PMID: 24915075 PMCID: PMC4051519 DOI: 10.1107/s2053230x14007341] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 04/02/2014] [Indexed: 11/10/2022] Open
Abstract
Using directed evolution based on random mutagenesis and heat-treated selection, a thermostable His170Tyr mutant of Geobacillus stearothermophilus thermostable p-nitrophenylphosphatase (TpNPPase) was obtained. The temperature at which the His170Tyr mutant lost 50% of its activity (T1/2) was found to be 4.40 K higher than that of wild-type TpNPPase, and the melting temperature of the His170Tyr mutant increased by 2.39 K. The crystal structure of the His170Tyr mutant was then determined at 2.0 Å resolution in the presence of a sodium ion and a sulfate ion in the active site. The cap domain of chain B shows a half-closed conformation. The hydrophobic side chain of the mutated residue, the hydroxyphenyl group, forms a hydrophobic contact with the methyl group of Ala166. This hydrophobic interaction was found using the Protein Interactions Calculator (PIC) web server with an interaction distance of 4.6 Å, and might be a key factor in the thermostabilization of the His170Tyr mutant. This study potentially offers a molecular basis for both investigation of the catalytic mechanism and thermostable protein engineering.
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Affiliation(s)
- Tiantian Shen
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, People’s Republic of China
| | - Zheng Guo
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, People’s Republic of China
| | - Chaoneng Ji
- State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai 200433, People’s Republic of China
- Shanghai Engineering Research Center Of Industrial Microorganisms, Shanghai, People’s Republic of China
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15
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Zheng H, Liu Y, Sun M, Han Y, Wang J, Sun J, Lu F. Improvement of alkali stability and thermostability of Paenibacillus campinasensis Family-11 xylanase by directed evolution and site-directed mutagenesis. ACTA ACUST UNITED AC 2014; 41:153-62. [DOI: 10.1007/s10295-013-1363-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 10/05/2013] [Indexed: 11/30/2022]
Abstract
Abstract
The extreme process condition of high temperature and high alkali limits the applications of most of natural xylanases in pulp and paper industry. Recently, various methods of protein engineering have been used to improve the thermal and alkalic tolerance of xylanases. In this work, directed evolution and site-directed mutagenesis were performed to obtain a mutant xylanase improved both on alkali stability and thermostability from the native Paenibacillus campinasensis Family-11 xylanase (XynG1-1). Mutant XynG1-1B43 (V90R/P172H) with two units increased in the optimum pH (pH 7.0–pH 9.0) and significant improvement on alkali stability was selected from the second round of epPCR library. And the further thermoduric mutant XynG1-1B43cc16 (V90R/P172H/T84C-T182C/D16Y) with 10 °C increased in the optimum temperature (60–70 °C) was then obtained by introducing a disulfide bridge (T84C-T182C) and a single amino acid substitution (D16Y) to XynG1-1B43 using site-directed mutagenesis. XynG1-1B43cc16 also showed higher thermostability and catalytic efficiency (k cat/K m) than that of wild-type (XynG1-1) and XynG1-1B43. The attractive improved properties make XynG1-1B43cc16 more suitable for bioleaching of cotton stalk pulp under the extreme process condition of high temperature (70 °C) and high alkali (pH 9.0).
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Affiliation(s)
- Hongchen Zheng
- grid.419897.a 000000040369313X Key Laboratory of Industrial Fermentation Microbiology Education Ministry of China 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
- grid.469560.8 Chinese Academy of Agricultural Engineering 100125 Beijing China
| | - Yihan Liu
- grid.419897.a 000000040369313X Key Laboratory of Industrial Fermentation Microbiology Education Ministry of China 300457 Tianjin China
- Tianjin Key Laboratory of Industrial Microbiology 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
| | - Mingzhe Sun
- National Engineering Laboratory for Industrial Enzymes (NELIE) 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
| | - Yang Han
- grid.419897.a 000000040369313X Key Laboratory of Industrial Fermentation Microbiology Education Ministry of China 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
| | - Jianling Wang
- Tianjin Key Laboratory of Industrial Microbiology 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
| | - Junshe Sun
- grid.469560.8 Chinese Academy of Agricultural Engineering 100125 Beijing China
| | - Fuping Lu
- grid.419897.a 000000040369313X Key Laboratory of Industrial Fermentation Microbiology Education Ministry of China 300457 Tianjin China
- National Engineering Laboratory for Industrial Enzymes (NELIE) 300457 Tianjin China
- grid.413109.e 0000000097356249 Industrial Microbiology Laboratory, College of Biotechnology Tianjin University of Science & Technology No. 29, 13th Avenue, Tianjin Economic and Technological Development Area 300457 Tianjin China
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16
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Amino acid substitutions in the N-terminus, cord and α-helix domains improved the thermostability of a family 11 xylanase XynR8. ACTA ACUST UNITED AC 2012; 39:1279-88. [DOI: 10.1007/s10295-012-1140-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2012] [Accepted: 04/21/2012] [Indexed: 01/19/2023]
Abstract
Abstract
The thermostability of xylanase XynR8 from uncultured Neocallimastigales rumen fungal was improved by combining random point mutagenesis with site-directed mutagenesis guided by rational design, and a thermostable variant, XynR8_VNE, was identified. This variant contained three amino acid substitutions, I38V, D137N and G151E, and showed an increased melting temperature of 8.8 °C in comparison with the wild type. At 65 °C the wild-type enzyme lost all of its activity after treatment for 30 min, but XynR8_VNE retained about 65 % activity. To elucidate the mechanism of thermal stabilization, three-dimensional structures were predicted for XynR8 and its variant. We found that the tight packing density and new salt bridge caused by the substitutions may be responsible for the improved thermostability. These three substitutions are located in the N-terminus, cord and α-helix domains, respectively. Hence, the stability of these three domains may be crucial for the thermostability of family 11 xylanases.
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17
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Verma D, Satyanarayana T. Molecular approaches for ameliorating microbial xylanases. BIORESOURCE TECHNOLOGY 2012; 117:360-367. [PMID: 22595098 DOI: 10.1016/j.biortech.2012.04.034] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 04/09/2012] [Accepted: 04/11/2012] [Indexed: 05/31/2023]
Abstract
In industrial processes, chemical catalysis is being replaced by enzyme catalysis, since the latter is environmentally benign, non-persistent and cost effective. Microbial xylanases have significant applications in textile, baking, food and feed industries, and in paper and pulp industries for reducing the chlorine requirement. The hazardous chlorine required for bleaching can be reduced up to 25-30% by including an enzymatic step in the pulp bleaching process. The paper pulp bleaching requires xylanases that are active at alkaline pH and elevated temperatures. The enzymes from the cultured microbes do not perform optimally in the paper industry due to their inadequate stability under the process conditions of high temperature and alkaline pH. This review, therefore, deals with the rationale of molecular approaches such as protein engineering for designing xylanases with improved characteristics to suit the process conditions in industries, and prospects and problems.
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Affiliation(s)
- Digvijay Verma
- Department of Microbiology, University of Delhi South Campus, New Delhi 110 021, India
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18
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Wang Y, Fu Z, Huang H, Zhang H, Yao B, Xiong H, Turunen O. Improved thermal performance of Thermomyces lanuginosus GH11 xylanase by engineering of an N-terminal disulfide bridge. BIORESOURCE TECHNOLOGY 2012; 112:275-279. [PMID: 22425398 DOI: 10.1016/j.biortech.2012.02.092] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 02/15/2012] [Accepted: 02/17/2012] [Indexed: 05/31/2023]
Abstract
In order to increase the stability of thermophilic Thermomyces lanuginosus GH11 xylanase, TLX, a disulfide bridge Q1C-Q24C was introduced into the N-terminal region of the enzyme. The apparent temperature optimum shifted upwards at pH 6.5 by about 10°C to 75°C. The resistance to thermal inactivation also increased by about 10°C. The melting temperature measured by CD spectroscopy increased from 66 to 74°C. Therefore the N-terminal disulfide bridge increased both kinetic and thermodynamic stability almost equally. At pH 8 and 70°C, the disulfide bridge increased the enzyme half-life 20-fold in the presence of substrate. In contrast to the situation in acidic-neutral pH, the substrate decreased the thermostability of xylanases in alkaline pH. The upper limit for the performance of the disulfide bridge mutant at pH 9 was 75°C. This study showed that N-terminal disulfide bridges can stabilize even thermostable family GH11 xylanases.
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Affiliation(s)
- Yawei Wang
- Engineering Research Centre of Bioresources in Southern China, College of Life Science, South-central University for Nationalities, Wuhan 430074, China
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Kim HM, Lee YG, Patel DH, Lee KH, Lee DS, Bae HJ. Characteristics of bifunctional acidic endoglucanase (Cel5B) from Gloeophyllum trabeum. J Ind Microbiol Biotechnol 2012; 39:1081-9. [PMID: 22395898 DOI: 10.1007/s10295-012-1110-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 02/15/2012] [Indexed: 11/27/2022]
Abstract
The endoglucanase (Cel5B) from the filamentous fungus Gloeophyllum trabeum was cloned and expressed without a signal peptide, and alanine residue 22 converted to glutamine in Pichia pastoris GS115. The DNA sequence of Cel5B had an open reading frame of 1,077 bp, encoding a protein of 359 amino acid residues with a molecular weight of 47 kDa. On the basis of sequence similarity, Cel5B displayed active site residues at Glu-175 and Glu-287. Both residues lost full hydrolytic activity when replaced with alanine through point mutation. The purified recombinant Cel5B showed very high specific activity, about 80- to 1,000-fold and 13- to 70-fold in comparison with other endoglucanases and cellobiohydrolase, on carboxymethylcellulose and filter paper, respectively, at pH 3.5 and 55°C. Cel5B displayed bifunctional characteristics under acidic conditions. The kinetic properties of the enzyme determined using a Lineweaver-Burk plot indicated that Cel5B is a catalytically efficient cellulolytic enzyme. These results suggest that Cel5B has high bifunctional endo- and exoglucanase activity under acidic conditions and is a good candidate for bioconversion of lignocellulose.
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Affiliation(s)
- Ho Myeong Kim
- Department of Forest Products and Technology, Chonnam National University, Gwangju, 500-757, Republic of Korea
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20
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Paës G, Berrin JG, Beaugrand J. GH11 xylanases: Structure/function/properties relationships and applications. Biotechnol Adv 2011; 30:564-92. [PMID: 22067746 DOI: 10.1016/j.biotechadv.2011.10.003] [Citation(s) in RCA: 275] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Revised: 10/06/2011] [Accepted: 10/13/2011] [Indexed: 01/02/2023]
Abstract
For technical, environmental and economical reasons, industrial demands for process-fitted enzymes have evolved drastically in the last decade. Therefore, continuous efforts are made in order to get insights into enzyme structure/function relationships to create improved biocatalysts. Xylanases are hemicellulolytic enzymes, which are responsible for the degradation of the heteroxylans constituting the lignocellulosic plant cell wall. Due to their variety, xylanases have been classified in glycoside hydrolase families GH5, GH8, GH10, GH11, GH30 and GH43 in the CAZy database. In this review, we focus on GH11 family, which is one of the best characterized GH families with bacterial and fungal members considered as true xylanases compared to the other families because of their high substrate specificity. Based on an exhaustive analysis of the sequences and 3D structures available so far, in relation with biochemical properties, we assess biochemical aspects of GH11 xylanases: structure, catalytic machinery, focus on their "thumb" loop of major importance in catalytic efficiency and substrate selectivity, inhibition, stability to pH and temperature. GH11 xylanases have for a long time been used as biotechnological tools in various industrial applications and represent in addition promising candidates for future other uses.
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Affiliation(s)
- Gabriel Paës
- INRA, UMR614 FARE, 2 esplanade Roland-Garros, F-51686 Reims, France.
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21
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Adén J, Wallgren M, Storm P, Weise CF, Christiansen A, Schröder WP, Funk C, Wolf-Watz M. Extraordinary μs-ms backbone dynamics in Arabidopsis thaliana peroxiredoxin Q. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1880-90. [PMID: 21798375 DOI: 10.1016/j.bbapap.2011.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/27/2011] [Accepted: 07/12/2011] [Indexed: 11/29/2022]
Abstract
Peroxiredoxin Q (PrxQ) isolated from Arabidopsis thaliana belongs to a family of redox enzymes called peroxiredoxins, which are thioredoxin- or glutaredoxin-dependent peroxidases acting to reduce peroxides and in particular hydrogen peroxide. PrxQ cycles between an active reduced state and an inactive oxidized state during its catalytic cycle. The catalytic mechanism involves a nucleophilic attack of the catalytic cysteine on hydrogen peroxide to generate a sulfonic acid intermediate with a concerted release of a water molecule. This intermediate is subsequently relaxed by the reaction of a second cysteine, denoted the resolving cysteine, generating an intramolecular disulfide bond and release of a second water molecule. PrxQ is recycled to the active state by a thioredoxin-dependent reduction. Previous structural studies of PrxQ homologues have provided the structural basis for the switch between reduced and oxidized conformations. Here, we have performed a detailed study of the activity, structure and dynamics of PrxQ in both the oxidized and reduced states. Reliable and experimentally validated structural models of PrxQ in both oxidation states were generated using homology based modeling. Analysis of NMR spin relaxation rates shows that PrxQ is monomeric in both oxidized and reduced states. As evident from R(2) relaxation rates the reduced form of PrxQ undergoes unprecedented dynamics on the slow μs-ms timescale. The ground state of this conformational dynamics is likely the stably folded reduced state as implied by circular dichroism spectroscopy. We speculate that the extensive dynamics is intimately related to the catalytic function of PrxQ.
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Affiliation(s)
- Jörgen Adén
- Department of Chemistry, Umea University, Umea, Sweden
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22
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Llop-Tous I, Ortiz M, Torrent M, Ludevid MD. The expression of a xylanase targeted to ER-protein bodies provides a simple strategy to produce active insoluble enzyme polymers in tobacco plants. PLoS One 2011; 6:e19474. [PMID: 21559333 PMCID: PMC3084875 DOI: 10.1371/journal.pone.0019474] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Accepted: 04/04/2011] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Xylanases deserve particular attention due to their potential application in the feed, pulp bleaching and paper industries. We have developed here an efficient system for the production of an active xylanase in tobacco plants fused to a proline-rich domain (Zera) of the maize storage protein γ-zein. Zera is a self-assembling domain able to form protein aggregates in vivo packed in newly formed endoplasmic reticulum-derived organelles known as protein bodies (PBs). METHODOLOGY/PRINCIPAL FINDINGS Tobacco leaves were transiently transformed with a binary vector containing the Zera-xylanase coding region, which was optimized for plant expression, under the control of the 35S CaMV promoter. The fusion protein was efficiently expressed and stored in dense PBs, resulting in yields of up to 9% of total protein. Zera-xylanase was post-translationally modified with high-mannose-type glycans. Xylanase fused to Zera was biologically active not only when solubilized from PBs but also in its insoluble form. The resistance of insoluble Zera-xylanase to trypsin digestion demonstrated that the correct folding of xylanase in PBs was not impaired by Zera oligomerization. The activity of insoluble Zera-xylanase was enhanced when substrate accessibility was facilitated by physical treatments such as ultrasound. Moreover, we found that the thermostability of the enzyme was improved when Zera was fused to the C-terminus of xylanase. CONCLUSION/SIGNIFICANCE In the present work we have successfully produced an active insoluble aggregate of xylanase fused to Zera in plants. Zera-xylanase chimeric protein accumulates within ER-derived protein bodies as active aggregates that can easily be recovered by a simple density-based downstream process. The production of insoluble active Zera-xylanase protein in tobacco outlines the potential of Zera as a fusion partner for producing enzymes of biotechnological relevance. Zera-PBs could thus become efficient and low-cost bioreactors for industrial purposes.
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Affiliation(s)
- Immaculada Llop-Tous
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG, Consortium CSIC-IRTA-UAB), Barcelona, Spain
- ERA Biotech, Barcelona, Spain
| | - Miriam Ortiz
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG, Consortium CSIC-IRTA-UAB), Barcelona, Spain
| | - Margarita Torrent
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG, Consortium CSIC-IRTA-UAB), Barcelona, Spain
| | - M. Dolors Ludevid
- Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG, Consortium CSIC-IRTA-UAB), Barcelona, Spain
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You C, Huang Q, Xue H, Xu Y, Lu H. Potential hydrophobic interaction between two cysteines in interior hydrophobic region improves thermostability of a family 11 xylanase fromNeocallimastix Patriciarum. Biotechnol Bioeng 2010; 105:861-70. [DOI: 10.1002/bit.22623] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Dumon C, Varvak A, Wall MA, Flint JE, Lewis RJ, Lakey JH, Morland C, Luginbühl P, Healey S, Todaro T, DeSantis G, Sun M, Parra-Gessert L, Tan X, Weiner DP, Gilbert HJ. Engineering hyperthermostability into a GH11 xylanase is mediated by subtle changes to protein structure. J Biol Chem 2008; 283:22557-64. [PMID: 18515360 DOI: 10.1074/jbc.m800936200] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Understanding the structural basis for protein thermostability is of considerable biological and biotechnological importance as exemplified by the industrial use of xylanases at elevated temperatures in the paper pulp and animal feed sectors. Here we have used directed protein evolution to generate hyperthermostable variants of a thermophilic GH11 xylanase, EvXyn11. The Gene Site Saturation Mutagenesis (GSSM) methodology employed assesses the influence on thermostability of all possible amino acid substitutions at each position in the primary structure of the target protein. The 15 most thermostable mutants, which generally clustered in the N-terminal region of the enzyme, had melting temperatures (Tm) 1-8 degrees C higher than the parent protein. Screening of a combinatorial library of the single mutants identified a hyperthermostable variant, EvXyn11TS, containing seven mutations. EvXyn11TS had a Tm approximately 25 degrees C higher than the parent enzyme while displaying catalytic properties that were similar to EvXyn11. The crystal structures of EvXyn11 and EvXyn11TS revealed an absence of substantial changes to identifiable intramolecular interactions. The only explicable mutations are T13F, which increases hydrophobic interactions, and S9P that apparently locks the conformation of a surface loop. This report shows that the molecular basis for the increased thermostability is extraordinarily subtle and points to the requirement for new tools to interrogate protein folding at non-ambient temperatures.
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Affiliation(s)
- Claire Dumon
- Institute for Cell and Molecular Biosciences, Newcastle University, The Medical School, Newcastle Upon Tyne NE2 4HH, United Kingdom
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Beliën T, Verjans P, Courtin CM, Delcour JA. Phage display based identification of novel stabilizing mutations in glycosyl hydrolase family 11 B. subtilis endoxylanase XynA. Biochem Biophys Res Commun 2008; 368:74-80. [DOI: 10.1016/j.bbrc.2008.01.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 01/07/2008] [Indexed: 10/22/2022]
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