1
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Zhuang H, Zheng F, Zhang H, Wang J, Chen J. Efficacious bioconversion of alginate/cellulose to value-added oligosaccharides by alginate-degrading GH5 endoglucanase from Trichoderma asperellum. Int J Biol Macromol 2024; 270:131968. [PMID: 38704059 DOI: 10.1016/j.ijbiomac.2024.131968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/26/2024] [Accepted: 04/27/2024] [Indexed: 05/06/2024]
Abstract
Enzymatic degradation of lignocellulosic biomass provides an eco-friendly approach to produce value-added macromolecules, e.g., bioactive polysaccharides. A novel acidophilic GH5 β-1,4-endoglucanase (termed TaCel5) from Trichoderma asperellum ND-1 was efficiently expressed in Komagataella phaffii (∼1.5-fold increase, 38.42 U/mL). TaCel5 displayed both endoglucanase (486.3 U/mg) and alginate lyase (359.5 U/mg) enzyme activities. It had optimal pH 3.0 and strong pH stability (exceed 86 % activity retained over pH range 3.0-5.0). 80 % activity (both endoglucanase and alginate lyase) was retained in the presence of 15 % ethanol or 3.42 M NaCl. Analysis of action mode revealed that hydrolytic activity of TaCel5 required at least three glucose (cellotriose) residues, yielding mainly cellobiose. Glu241 and Glu352 are essential catalytic residues, while Asp106, Asp277 and Asp317 play auxiliary roles in cellulose degradation. TaCel5 displayed high hydrolysis efficiency for glucan and alginate substrates. ESI-MS analysis indicated that the enzymatic hydrolysates of alginate mainly contained disaccharides and heptasaccharides. This is the first detailed report of a bifunctional GH5 endoglucanase/alginate lyase enzyme from T. asperellum. Thus TaCel5 has strong potential in food and feed industries as a catalyst for bioconversion of cellulose- and alginate-containing waste materials into value-added products oligosaccharides, which was of great benefit both for the economy and environment.
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Affiliation(s)
- Huan Zhuang
- Department of ENT and Head & Neck Surgery, Children's Hospital Zhejiang University School of Medicine, Hangzhou 310051, Zhejiang, China
| | - Fengzhen Zheng
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310021, China.
| | - Hengbin Zhang
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310021, China
| | - Jiaqiang Wang
- College of Biological and Environmental Engineering, Zhejiang Shuren University, Hangzhou 310021, China
| | - Jun Chen
- Interdisciplinary Research Academy, Zhejiang Shuren University, Hangzhou 310021, China
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2
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Dementiev A, Lillington SP, Jin S, Kim Y, Jedrzejczak R, Michalska K, Joachimiak A, O'Malley MA. Structure and enzymatic characterization of CelD endoglucanase from the anaerobic fungus Piromyces finnis. Appl Microbiol Biotechnol 2023; 107:5999-6011. [PMID: 37548665 PMCID: PMC10485095 DOI: 10.1007/s00253-023-12684-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/24/2023] [Accepted: 06/29/2023] [Indexed: 08/08/2023]
Abstract
Anaerobic fungi found in the guts of large herbivores are prolific biomass degraders whose genomes harbor a wealth of carbohydrate-active enzymes (CAZymes), of which only a handful are structurally or biochemically characterized. Here, we report the structure and kinetic rate parameters for a glycoside hydrolase (GH) family 5 subfamily 4 enzyme (CelD) from Piromyces finnis, a modular, cellulosome-incorporated endoglucanase that possesses three GH5 domains followed by two C-terminal fungal dockerin domains (double dockerin). We present the crystal structures of an apo wild-type CelD GH5 catalytic domain and its inactive E154A mutant in complex with cellotriose at 2.5 and 1.8 Å resolution, respectively, finding the CelD GH5 catalytic domain adopts the (β/α)8-barrel fold common to many GH5 enzymes. Structural superimposition of the apo wild-type structure with the E154A mutant-cellotriose complex supports a catalytic mechanism in which the E154 carboxylate side chain acts as an acid/base and E278 acts as a complementary nucleophile. Further analysis of the cellotriose binding pocket highlights a binding groove lined with conserved aromatic amino acids that when docked with larger cellulose oligomers is capable of binding seven glucose units and accommodating branched glucan substrates. Activity analyses confirm P. finnis CelD can hydrolyze mixed linkage glucan and xyloglucan, as well as carboxymethylcellulose (CMC). Measured kinetic parameters show the P. finnis CelD GH5 catalytic domain has CMC endoglucanase activity comparable to other fungal endoglucanases with kcat = 6.0 ± 0.6 s-1 and Km = 7.6 ± 2.1 g/L CMC. Enzyme kinetics were unperturbed by the addition or removal of the native C-terminal dockerin domains as well as the addition of a non-native N-terminal dockerin, suggesting strict modularity among the domains of CelD. KEY POINTS: • Anaerobic fungi host a wealth of industrially useful enzymes but are understudied. • P. finnis CelD has endoglucanase activity and structure common to GH5_4 enzymes. • CelD's kinetics do not change with domain fusion, exhibiting high modularity.
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Affiliation(s)
- Alexey Dementiev
- Structural Biology Center, X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Stephen P Lillington
- Department of Chemical Engineering, University of California, Santa Barbara, CA, USA
| | - Shiyan Jin
- Department of Chemical Engineering, University of California, Santa Barbara, CA, USA
| | - Youngchang Kim
- Structural Biology Center, X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Robert Jedrzejczak
- Structural Biology Center, X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Karolina Michalska
- Structural Biology Center, X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Andrzej Joachimiak
- Structural Biology Center, X-Ray Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, CA, USA.
- Biological Engineering Program, University of California, Santa Barbara, CA, USA.
- Joint BioEnergy Institute (JBEI), Emeryville, CA, 94608, USA.
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3
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Neis A, da Silva Pinto L. Glycosyl hydrolases family 5, subfamily 5: Relevance and structural insights for designing improved biomass degrading cocktails. Int J Biol Macromol 2021; 193:980-995. [PMID: 34666133 DOI: 10.1016/j.ijbiomac.2021.10.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 10/20/2022]
Abstract
Endoglucanases are carbohydrate-degrading enzymes widely used for bioethanol production as part of the enzymatic cocktail. However, family 5 subfamily 5 (GH5_5) endoglucanases are still poorly explored in depth. The Trichoderma reesei representative is the most studied enzyme, presenting catalytic activity in acidic media and mild temperature conditions. Though biochemically similar, its modular structure and synergy with other components vary greatly compared to other GH5_5 members and there is still a lack of specific studies regarding their interaction with other cellulases and application on novel and better mixtures. In this regard, the threedimensional structure elucidation is a highly valuable tool to both uncover basic catalytic mechanisms and implement engineering techniques, proved by the high success rate GH5_5 endoglucanases show. GH5_5 enzymes must be carefully evaluated to fully uncover their potential in biomass-degrading cocktails: the optimal industrial conditions, synergy with other cellulases, structural studies, and enzyme engineering approaches. We aimed to provide the current understanding of these main topics, collecting all available information about characterized GH5_5 endoglucanases function, structure, and bench experiments, in order to suggest future directions to a better application of these enzymes in the industry.
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Affiliation(s)
- Alessandra Neis
- Laboratório de Bioinformática e Proteômica (BioPro Lab), Centro de Desenvolvimento Tecnológico, Campus Universitário, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, Caixa Postal 96010-900, Brazil.
| | - Luciano da Silva Pinto
- Laboratório de Bioinformática e Proteômica (BioPro Lab), Centro de Desenvolvimento Tecnológico, Campus Universitário, Universidade Federal de Pelotas, Pelotas, Rio Grande do Sul, Caixa Postal 96010-900, Brazil.
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4
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Kari J, Molina GA, Schaller KS, Schiano-di-Cola C, Christensen SJ, Badino SF, Sørensen TH, Røjel NS, Keller MB, Sørensen NR, Kolaczkowski B, Olsen JP, Krogh KBRM, Jensen K, Cavaleiro AM, Peters GHJ, Spodsberg N, Borch K, Westh P. Physical constraints and functional plasticity of cellulases. Nat Commun 2021; 12:3847. [PMID: 34158485 PMCID: PMC8219668 DOI: 10.1038/s41467-021-24075-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 05/17/2021] [Indexed: 11/16/2022] Open
Abstract
Enzyme reactions, both in Nature and technical applications, commonly occur at the interface of immiscible phases. Nevertheless, stringent descriptions of interfacial enzyme catalysis remain sparse, and this is partly due to a shortage of coherent experimental data to guide and assess such work. In this work, we produced and kinetically characterized 83 cellulases, which revealed a conspicuous linear free energy relationship (LFER) between the substrate binding strength and the activation barrier. The scaling occurred despite the investigated enzymes being structurally and mechanistically diverse. We suggest that the scaling reflects basic physical restrictions of the hydrolytic process and that evolutionary selection has condensed cellulase phenotypes near the line. One consequence of the LFER is that the activity of a cellulase can be estimated from its substrate binding strength, irrespectively of structural and mechanistic details, and this appears promising for in silico selection and design within this industrially important group of enzymes.
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Affiliation(s)
- Jeppe Kari
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Gustavo A Molina
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Kay S Schaller
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Corinna Schiano-di-Cola
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Stefan J Christensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Silke F Badino
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Nanna S Røjel
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | - Malene B Keller
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Frederiksberg C, Denmark
| | - Nanna Rolsted Sørensen
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | - Bartlomiej Kolaczkowski
- Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde, Denmark
| | | | | | | | | | - Günther H J Peters
- Department of Chemistry, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | | | - Peter Westh
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark.
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5
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Anuganti M, Fu H, Ekatan S, Kumar CV, Lin Y. Kinetic Study on Enzymatic Hydrolysis of Cellulose in an Open, Inhibition-Free System. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:5180-5192. [PMID: 33872034 DOI: 10.1021/acs.langmuir.1c00115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Due to the complexity of cellulases and the requirement of enzyme adsorption on cellulose prior to reactions, it is difficult to evaluate their reaction with a general mechanistic scheme. Nevertheless, it is of great interest to come up with an approximate analytic description of a valid model for the purpose of developing an intuitive understanding of these complex enzyme systems. Herein, we used the surface plasmonic resonance method to monitor the action of a cellobiohydrolase by itself, as well as its mixture with a synergetic endoglucanase, on the surface of a regenerated model cellulose film, under continuous flow conditions. We found a phenomenological approach by taking advantage of the long steady state of cellulose hydrolysis in the open, inhibition-free system. This provided a direct and reliable way to analyze the adsorption and reaction processes with a minimum number of fitting parameters. We investigated a generalized Langmuir-Michaelis-Menten model to describe a full set of kinetic results across a range of enzyme concentrations, compositions, and temperatures. The overall form of the equations describing the pseudo-steady-state kinetics of the flow-system shares some interesting similarities with the Michaelis-Menten equation. The use of familiar Michaelis-Menten parameters in the analysis provides a unifying framework to study cellulase kinetics. The strategy may provide a shortcut for approaching a quantitative while intuitive understanding of enzymatic degradation of cellulose from top to bottom. The open system approach and the kinetic analysis should be applicable to a variety of cellulases and reaction systems to accelerate the progress in the field.
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Affiliation(s)
- Murali Anuganti
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Hailin Fu
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Stephen Ekatan
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Challa V Kumar
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Yao Lin
- Department of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
- Polymer Program, Institute of Material Sciences, University of Connecticut, Storrs, Connecticut 06269, United States
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Miao T, Basit A, Wen J, Liu J, Zheng F, Cao Y, Jiang W. High efficient degradation of glucan/glucomannan to cello-/mannan-oligosaccharide by endoglucanase via tetrasaccharide as intermediate. Food Chem 2021; 350:129175. [PMID: 33610847 DOI: 10.1016/j.foodchem.2021.129175] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 11/27/2020] [Accepted: 01/19/2021] [Indexed: 12/19/2022]
Abstract
Here, we report an efficient endoglucanase from Aureobasidium pullulans (termed ApCel5A) was expressed in Pichia pastoris. ApCel5A shows two different enzyme activities of endoglucanase (1270 U/mg) and mannanase (31.2 U/mg). Through engineering the signal peptide and fed-batch fermentation, the enzyme activity of endoglucanase was improved to 6.63-folds, totally. Its efficient synergism with Celluclast 1.5 L, excellent tolerance to low pH (2.5), cholate and protease suggests potential application in bioresources, food and feed industries. Site-directed mutagenesis experiments present that ApCel5A residues Glu245 and Glu358 are key catalytic sites, while Asp118, Asp122, Asp198 and Asp314 play an auxiliary role. More importantly, ApCel5A display high degradation efficiency of glucan and glucomannan substrates by using tetrasaccharide contained reducing end of glucose residue as an intermediate. This study elucidated the effective methods to improve an endoglucanase expression and detailed catalytic mechanism for degradation of various substrates, which provides a new insight for endoglucanase application.
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Affiliation(s)
- Ting Miao
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Abdul Basit
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China; Department of Microbiology and Molecular Genetics, Faculty of Life Sciences, University of Okara, Punjab 56300, Pakistan
| | - Jiaqi Wen
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Junquan Liu
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Fengzhen Zheng
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yunhe Cao
- State Key Laboratory of Animal Nutrition, China Agricultural, University, Beijing, China.
| | - Wei Jiang
- State Key Laboratory of Agro-Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
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7
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Durham EK, Sastry SK. Moderate Electric Field Treatment Enhances Enzymatic Hydrolysis of Cellulose at Below-Optimal Temperatures. Enzyme Microb Technol 2020; 142:109678. [PMID: 33220866 DOI: 10.1016/j.enzmictec.2020.109678] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/16/2020] [Accepted: 09/29/2020] [Indexed: 11/25/2022]
Abstract
Saccharification of cellulosic biomass for the fermentation of transportation fuels faces several challenges. Cellulose is highly stable, and even with enzymatic assistance, decomposition of cellulose is slow. Additionally, the enzymes are expensive and sensitive to thermal and mechanical inactivation. In this work, we studied the effects of moderate electric field (MEF, in the range from 1 to 1000 V per cm) treatments on the effectiveness of enzymatic saccharification. MEF treatments were applied to determine their effects on enzyme activity. We considered the effects of field strength, frequency, application regime and temperature. It was found that the enzyme responded to alterations in the frequency of the waveform, with 50 to 60 Hz maximizing the effects of the field, although the effects of field strength and application regime were more significant. It was found that the electric field could have a positive, negative, or negligible effect depending on the field strength. Most notably, when MEF treatments were applied over a range of temperatures, it was found that MEF treatment significantly improved enzyme activity at lower temperatures, leading to the observation that MEF treatment imitates a temperature increase. Calculations simulating the electrophoretic motion of the enzymes verified that the magnitude of motion associated with the MEF treatments was qualitatively similar to the change in molecular motion associated with temperature increases.
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Affiliation(s)
- Emily K Durham
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Drive, Columbus, OH, 43210, USA.
| | - Sudhir K Sastry
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Drive, Columbus, OH, 43210, USA.
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8
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Glycosyl hydrolase catalyzed glycosylation in unconventional media. Appl Microbiol Biotechnol 2020; 104:9523-9534. [PMID: 33034701 DOI: 10.1007/s00253-020-10924-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 02/07/2023]
Abstract
The reversible hydrolytic property of glycosyl hydrolases (GHs) as well as their acceptance of aglycones other than water has provided the abilities of GHs in synthesizing glycosides. Together with desirable physiochemical properties of glycosides and their high commercial values, research interests have been aroused to investigate the synthetic other than the hydrolytic properties of GHs. On the other hand, just like the esterification processes catalyzed by lipases, GH synthetic effectiveness is strongly obstructed by water both thermodynamically and kinetically. Medium engineering by involving organic solvents can be a viable approach to alleviate the obstacles caused by water. However, as native hydrolyases function in water-enriched environments, most GHs display poor catalytic performance in the presence of organic solvents. Some GHs from thermophiles are more tolerant to organic solvents due to their robust folded structures with strong residue interactions. Other than native sources, immobilization, protein engineering, employment of surfactant, and lyophilization have been proved to enhance the GH stability from the native state, which opens up the possibilities for GHs to be employed in unconventional media as synthases. KEY POINTS: • Unconventional media enhance the synthetic ability but destabilize GHs. • Viable approaches are discussed to improve GH stability from the native state. • GHs robust in unconventional media can be valuable industrial synthases.
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9
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Singh S, Kumar K, Nath P, Goyal A. Role of glycine 256 residue in improving the catalytic efficiency of mutant endoglucanase of family 5 glycoside hydrolase from Bacillus amyloliquefaciens SS35. Biotechnol Bioeng 2020; 117:2668-2682. [PMID: 32484905 DOI: 10.1002/bit.27448] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/24/2020] [Accepted: 05/31/2020] [Indexed: 11/07/2022]
Abstract
Wild-type, BaGH5-WT and mutant, BaGH5-UV2 (aspartate residue mutated to glycine), endoglucanases belonging to glycoside hydrolase family 5 (GH5), from wild-type, and UV2 mutant strain of Bacillus amyloliquefaciens SS35, respectively, were earlier cloned in pHTP0 cloning vector. In this study, genes encoding BaGH5-WT or BaGH5-UV2 were cloned into pET28a(+) expression-vector and expressed in Escherichia coli BL-21(DE3)pLysS cells. BaGH5-UV2 showed 10-fold (43.6 U/mg) higher specific activity against carboxymethylcellulose sodium salt (CMC-Na), higher optimal temperature by 10°C at 65°C, and 22-fold higher catalytic efficiency against CMC-Na, than BaGH5-WT. BaGH5-UV2 showed stability in wider acidic pH range (5.0-7.0) unlike BaGH5-WT in narrow basic pH range (7.0-7.5). BaGH5-UV2 displayed a mutation, Asp256Gly in L11 loop, connecting β6 -sheet with α6 -helix, near active site toward the domain surface of (α/β)8 -TIM barrel fold. Molecular dynamics simulation studies showed more stable structure, accessibility of substrate for a catalytic site, and increased flexibility of loop L11 of BaGH5-UV2 than the wild type, suggesting enhanced catalysis by BaGH5-UV2. Molecular docking analysis displayed enhanced hydrogen bond interactions of cello-oligosaccharides with BaGH5-UV2, unlike BaGH5-WT. Thus, Gly256 residue of loop L11 plays an important role in enhancing catalytic efficiency, and pH stability of GH5 endoglucanase. Therefore, these results help in protein engineering of GH5 endoglucanase for improved biochemical properties.
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Affiliation(s)
- Shweta Singh
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Krishan Kumar
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Priyanka Nath
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, Assam, India
| | - Arun Goyal
- Carbohydrate Enzyme Biotechnology Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, India.,DBT PAN-IIT Centre for Bioenergy, Indian Institute of Technology Guwahati, Guwahati, Assam, India
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10
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Onuma H, Hara K, Sugita K, Kano A, Fukuta Y, Shirasaka N. Purification and characterization of a glycoside hydrolase family 5 endoglucanase from Tricholoma matsutake grown on barley based solid-state medium. J Biosci Bioeng 2019; 128:669-676. [PMID: 31257006 DOI: 10.1016/j.jbiosc.2019.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 04/24/2019] [Accepted: 05/23/2019] [Indexed: 11/19/2022]
Abstract
An endoglucanase was isolated from solid-state culture of the ectomycorrhizal fungus Tricholoma matsutake (TmEgl5A) grown on rolled barley and vermiculite. The enzyme was purified by ammonium sulfate fractionation, ion-exchange, hydrophobic, and gel filtration. TmEgl5A showed a molecular mass of approximately 40 kDa as determined by SDS-PAGE. The single band of the protein was analyzed by peptide-mass-finger-printing using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the trypsin-digested peptide sequences were matched to a putative endoglucanase sequence (protein ID1465229) in the JGI T. matsutake 945 v3.0 genome database. Based on the sequence information, the gene encoding TmEgl was cloned and expressed in Pichia pastoris KM71H. The deduced amino acid sequence was similar to GH5 family endoglucanases from Basidiomycetes. The enzyme acts on barley β-glucan, lichenan, and CMC-Na. The hydrolyzation products from these substrates were detected by thin-layer chromatography as oligosaccharides with minimal disaccharides. These results suggested that T. matsutake produces a typical endoglucanase in solid-state culture, and the fungus has the potential to degrade β-linkage polysaccharides.
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Affiliation(s)
- Hiroki Onuma
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan
| | - Kento Hara
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan
| | - Kayo Sugita
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan
| | - Akiko Kano
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan
| | - Yasuhisa Fukuta
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan.
| | - Norifumi Shirasaka
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, 3327-204 Naka-machi, Nara 631-8505, Japan
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11
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Dutoit R, Delsaute M, Collet L, Vander Wauven C, Van Elder D, Berlemont R, Richel A, Galleni M, Bauvois C. Crystal structure determination of Pseudomonas stutzeri A1501 endoglucanase Cel5A: the search for a molecular basis for glycosynthesis in GH5_5 enzymes. Acta Crystallogr D Struct Biol 2019; 75:605-615. [PMID: 31205022 DOI: 10.1107/s2059798319007113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 05/16/2019] [Indexed: 01/23/2023] Open
Abstract
The discovery of new glycoside hydrolases that can be utilized in the chemoenzymatic synthesis of carbohydrates has emerged as a promising approach for various biotechnological processes. In this study, recombinant Ps_Cel5A from Pseudomonas stutzeri A1501, a novel member of the GH5_5 subfamily, was expressed, purified and crystallized. Preliminary experiments confirmed the ability of Ps_Cel5A to catalyze transglycosylation with cellotriose as a substrate. The crystal structure revealed several structural determinants in and around the positive subsites, providing a molecular basis for a better understanding of the mechanisms that promote and favour synthesis rather than hydrolysis. In the positive subsites, two nonconserved positively charged residues (Arg178 and Lys216) were found to interact with cellobiose. This adaptation has also been reported for transglycosylating β-mannanases of the GH5_7 subfamily.
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Affiliation(s)
| | - Maud Delsaute
- InBioS - Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, 13 Allée du 6 Août, 4000 Liège, Belgium
| | | | | | - Dany Van Elder
- Laboratory of Microbiology, Université Libre de Bruxelles, 12 Rue des Professeurs Jeener et Brachet, 6041 Gosselies, Belgium
| | - Renaud Berlemont
- Department of Biological Sciences, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, CA 90840-9502, USA
| | - Aurore Richel
- Gembloux Agro-Bio Tech, University of Liège, 2 Passage des Déportés, 5030 Gembloux, Belgium
| | - Moreno Galleni
- InBioS - Center for Protein Engineering (CIP), Biological Macromolecules, University of Liège, 13 Allée du 6 Août, 4000 Liège, Belgium
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Activity and Thermostability of GH5 Endoglucanase Chimeras from Mesophilic and Thermophilic Parents. Appl Environ Microbiol 2019; 85:AEM.02079-18. [PMID: 30552196 DOI: 10.1128/aem.02079-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 12/04/2018] [Indexed: 12/29/2022] Open
Abstract
Cellulases from glycoside hydrolase family 5 (GH5) are key endoglucanase enzymes in the degradation of diverse polysaccharide substrates and are used in industrial enzyme cocktails to break down biomass. The GH5 family shares a canonical (βα)8-barrel structure, where each (βα) module is essential for the enzyme's stability and activity. Despite their shared topology, the thermostability of GH5 endoglucanase enzymes can vary significantly, and highly thermostable variants are often sought for industrial applications. Based on the previously characterized thermophilic GH5 endoglucanase Egl5A from Talaromyces emersonii (TeEgl5A), which has an optimal temperature of 90°C, we created 10 hybrid enzymes with elements of the mesophilic endoglucanase Cel5 from Stegonsporium opalus (SoCel5) to determine which elements are responsible for enhanced thermostability. Five of the expressed hybrid enzymes exhibit enzyme activity. Two of these hybrids exhibited pronounced increases in the temperature optimum (10 and 20°C), the temperature at which the protein lost 50% of its activity (T 50) (15 and 19°C), and the melting temperature (Tm ) (16.5 and 22.9°C) and extended half-lives (t 1/2) (∼240- and 650-fold at 55°C) relative to the values for the mesophilic parent enzyme and demonstrated improved catalytic efficiency on selected substrates. The successful hybridization strategies were validated experimentally in another GH5 endoglucanase, Cel5 from Aspergillus niger (AnCel5), which demonstrated a similar increase in thermostability. Based on molecular dynamics (MD) simulations of both the SoCel5 and TeEgl5A parent enzymes and their hybrids, we hypothesize that improved hydrophobic packing of the interface between α2 and α3 is the primary mechanism by which the hybrid enzymes increase their thermostability relative to that of the mesophilic parent SoCel5.IMPORTANCE Thermal stability is an essential property of enzymes in many industrial biotechnological applications, as high temperatures improve bioreactor throughput. Many protein engineering approaches, such as rational design and directed evolution, have been employed to improve the thermal properties of mesophilic enzymes. Structure-based recombination has also been used to fuse TIM barrel fragments, and even fragments from unrelated folds, to generate new structures. However, little research has been done on GH5 endoglucanases. In this study, two GH5 endoglucanases exhibiting TIM barrel structure, SoCel5 and TeEgl5A, with different thermal properties, were hybridized to study the roles of different (βα) motifs. This work illustrates the role that structure-guided recombination can play in helping to identify sequence function relationships within GH5 enzymes by supplementing natural diversity with synthetic diversity.
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Disulfide bonds elimination of endoglucanase II from Trichoderma reesei by site-directed mutagenesis to improve enzyme activity and thermal stability: An experimental and theoretical approach. Int J Biol Macromol 2018; 120:1572-1580. [DOI: 10.1016/j.ijbiomac.2018.09.164] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 09/23/2018] [Accepted: 09/25/2018] [Indexed: 01/21/2023]
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Kalbarczyk KZ, Mazeau EJ, Rapp KM, Marchand N, Koffas MAG, Collins CH. Engineering Bacillus megaterium Strains To Secrete Cellulases for Synergistic Cellulose Degradation in a Microbial Community. ACS Synth Biol 2018; 7:2413-2422. [PMID: 30226981 DOI: 10.1021/acssynbio.8b00186] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent environmental concerns have intensified the need to develop systems to degrade waste biomass for use as an inexpensive carbon source for microbial chemical production. Current approaches to biomass utilization rely on pretreatment processes that include expensive enzymatic purification steps for the requisite cellulases. We aimed to engineer a synthetic microbial community to synergistically degrade cellulose by compartmentalizing the system with multiple specialized Bacillus megaterium strains. EGI1, an endoglucanase, and Cel9AT, a multimodular cellulase, were targeted for secretion from B. megaterium. A small library of signal peptides (SPs) with five amino acid linkers was selected to tag each cellulase for secretion from B. megaterium. Cellulase activity against amorphous cellulose was confirmed through a series of bioassays, and the most active SP constructs were identified as EGI1 with the LipA SP and Cel9AT with the YngK SP. The activity of the optimized cellulase secretion strains was characterized individually and in tandem to assess synergistic cellulolytic activity. The combination of EGI1 and Cel9AT yielded higher activity than either single cellulase. A coculture of EGI1 and Cel9AT secreting B. megaterium strains demonstrated synergistic behavior with higher activity than either monoculture. This cellulose degradation module can be further integrated with bioproduct synthesis modules to build complex systems for the production of high value molecules.
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Affiliation(s)
- Karolina Z. Kalbarczyk
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Emily J. Mazeau
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Kent M. Rapp
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Nicholas Marchand
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Mattheos A. G. Koffas
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Cynthia H. Collins
- Center for Biotechnology and Interdisciplinary Studies and Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
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Zheng F, Tu T, Wang X, Wang Y, Ma R, Su X, Xie X, Yao B, Luo H. Enhancing the catalytic activity of a novel GH5 cellulase GtCel5 from Gloeophyllum trabeum CBS 900.73 by site-directed mutagenesis on loop 6. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:76. [PMID: 29588661 PMCID: PMC5863444 DOI: 10.1186/s13068-018-1080-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 03/14/2018] [Indexed: 05/17/2023]
Abstract
BACKGROUND Cellulases of glycosyl hydrolase (GH) family 5 share a (β/α)8 TIM-barrel fold structure with eight βα loops surrounding the catalytic pocket. These loops exposed on the surface play a vital role in protein functions, primarily due to the interactions of some key amino acids with solvent and ligand molecules. It has been reported that motions of these loops facilitate substrate access and product release, and loops 6 and 7 located at the substrate entrance of the binding pocket promote proton transfer reaction at the catalytic site motions. However, the role of these flexible loops in catalysis of GH5 cellulase remains to be explored. RESULTS In the present study, an acidic, mesophilic GH5 cellulase (with optimal activity at pH 4.0 and 70 °C), GtCel5, was identified in Gloeophyllum trabeum CBS 900.73. The specific activities of GtCel5 toward CMC-Na, barley β-glucan, and lichenan were 1117 ± 43, 6257 ± 26 and 5318 ± 54 U/mg, respectively. Multiple sequence alignment indicates that one amino acid residue at position 233 on the loop 6 shows semi-conservativeness and might contribute to the great catalytic performance. Saturation mutagenesis at position 233 was then conducted to reveal the vital roles of this position in enzyme properties. In comparison to the wild type, variants N233A and N233G showed decreased optimal temperature (- 10 °C) but increased activities (27 and 70%) and catalytic efficiencies (kcat/Km; 45 and 52%), respectively. The similar roles of position 233 in catalytic performance were also verified in the other two GH5 homologs, TeEgl5A and PoCel5, by reverse mutation. Further molecular dynamics simulations suggested that the substitution of asparagine with alanine or glycine may introduce more hydrogen bonds, increase the flexibility of loop 6, enhance the interactions between enzyme and substrate, and thus improve the substrate affinity and catalytic efficiency. CONCLUSION This study proposed a novel cellulase with potentials for industrial application. A specific position was identified to play key roles in cellulase-substrate interactions and enzyme catalysis. It is of great importance for understanding the binding mechanism of GH5 cellulases, and provides an effective strategy to improve the catalytic performance of cellulases.
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Affiliation(s)
- Fei Zheng
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 People’s Republic of China
| | - Tao Tu
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
| | - Xiaoyu Wang
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 People’s Republic of China
| | - Yuan Wang
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
| | - Rui Ma
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
| | - Xiaoyun Su
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
| | - Xiangming Xie
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, 100083 People’s Republic of China
| | - Bin Yao
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
| | - Huiying Luo
- Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun Street, Haidian, Beijing, 100081 People’s Republic of China
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Hansson H, Karkehabadi S, Mikkelsen N, Douglas NR, Kim S, Lam A, Kaper T, Kelemen B, Meier KK, Jones SM, Solomon EI, Sandgren M. High-resolution structure of a lytic polysaccharide monooxygenase from Hypocrea jecorina reveals a predicted linker as an integral part of the catalytic domain. J Biol Chem 2017; 292:19099-19109. [PMID: 28900033 DOI: 10.1074/jbc.m117.799767] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/29/2017] [Indexed: 12/17/2022] Open
Abstract
For decades, the enzymes of the fungus Hypocrea jecorina have served as a model system for the breakdown of cellulose. Three-dimensional structures for almost all H. jecorina cellulose-degrading enzymes are available, except for HjLPMO9A, belonging to the AA9 family of lytic polysaccharide monooxygenases (LPMOs). These enzymes enhance the hydrolytic activity of cellulases and are essential for cost-efficient conversion of lignocellulosic biomass. Here, using structural and spectroscopic analyses, we found that native HjLPMO9A contains a catalytic domain and a family-1 carbohydrate-binding module (CBM1) connected via a linker sequence. A C terminally truncated variant of HjLPMO9A containing 21 residues of the predicted linker was expressed at levels sufficient for analysis. Here, using structural, spectroscopic, and biochemical analyses, we found that this truncated variant exhibited reduced binding to and activity on cellulose compared with the full-length enzyme. Importantly, a 0.95-Å resolution X-ray structure of truncated HjLPMO9A revealed that the linker forms an integral part of the catalytic domain structure, covering a hydrophobic patch on the catalytic AA9 module. We noted that the oxidized catalytic center contains a Cu(II) coordinated by two His ligands, one of which has a His-brace in which the His-1 terminal amine group also coordinates to a copper. The final equatorial position of the Cu(II) is occupied by a water-derived ligand. The spectroscopic characteristics of the truncated variant were not measurably different from those of full-length HjLPMO9A, indicating that the presence of the CBM1 module increases the affinity of HjLPMO9A for cellulose binding, but does not affect the active site.
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Affiliation(s)
- Henrik Hansson
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Saeid Karkehabadi
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | - Nils Mikkelsen
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden
| | | | - Steve Kim
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Anna Lam
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Thijs Kaper
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Brad Kelemen
- DuPont Industrial Biosciences, Palo Alto, California 94304, and
| | - Katlyn K Meier
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Stephen M Jones
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Edward I Solomon
- the Department of Chemistry, Stanford University, Stanford, California 94305
| | - Mats Sandgren
- From the Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, P.O. Box 7015, SE-750 07 Uppsala, Sweden,
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Vakhrusheva AV, Nemashkalov VA, Kravchenko OV, Tishchenko SV, Gabdulkhakov AG, Kljashtorny VG, Korotkova OG, Gusakov AV, Sinitsyn AP. Structural investigation of endoglucanase 2 from the filamentous fungus Penicillium verruculosum. CRYSTALLOGR REP+ 2017. [DOI: 10.1134/s1063774517020304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Functional diversity for biomass deconstruction in family 5 subfamily 5 (GH5_5) of fungal endo-β1,4-glucanases. Appl Microbiol Biotechnol 2017; 101:4093-4101. [PMID: 28197688 DOI: 10.1007/s00253-017-8168-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 12/21/2022]
Abstract
Endo-β1,4-glucanases in glycosyl hydrolase family 5 (GH5) are ubiquitous enzymes in the multicellular fungi and are common components of enzyme cocktails for biomass conversion. We recently showed that an endo-glucanase of subfamily 5 of GH5 (GH5_5) from Sporotrichum thermophile (StCel5A) was more effective at releasing glucose from pretreated corn stover, when part of an eight-component synthetic enzyme mixture, compared to its closely related counterpart from Trichoderma reesei, TrCel5A. StCel5A and TrCel5A belong to different clades of GH5_5 (GH5_5_1 and GH5_5_2, respectively). To test whether the superior activity of StCel5A was a general property of all enzymes in the GH5_5_2 clade, StCel5A, TrCel5A, and two additional members of each subfamily were expressed in a common host that had been engineered to suppress its native cellulases (T. reesei Δxyr1) and compared against each other alone on pure substrates, in synthetic mixtures on pure substrates, and against each other in synthetic mixtures on real biomass. The results indicated that superiority is a unique property of StCel5A and not of GH5_5_2 generally. The six Cel5A enzymes had significant differences in relative activities on different substrates, in specific activities, and in sensitivities to mannan inhibition. Importantly, the behavior of the six endo-glucanases on pure cellulose substrates did not predict their behavior in combination with other cellulolytic enzymes on a real lignocellulosic biomass substrate.
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Yan S, Yao L, Kang B, Lee JY. Solvent effect on hydrogen bonded Tyr⋯Asp⋯Arg triads: Enzymatic catalyzed model system. Comput Biol Chem 2016; 65:140-147. [PMID: 27825065 DOI: 10.1016/j.compbiolchem.2016.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 10/06/2016] [Accepted: 10/29/2016] [Indexed: 10/20/2022]
Abstract
The hydrogen bond plays a vital role in structural arrangement, intermediate state stabilization, materials function, and biological activity of certain enzymatic reactions. The solvent and electronic effects on hydrogen bonds are illustrated employing the polarizable contimuum model at B3LYP/6-311++G(d,p) level. Geometry optimizations reflect the significant solvent and electronic effect. The proton departs spontaneously upon oxidation from the hydroxyl group of tyrosyl in hydrogen bonded Tyr⋯Asp⋯Arg triads in both gas phase and solvents. The electron transfer isomers are observed for anionic triads, no matter what the solvent is. The difference of distance between two hydrogen bonds is enlarged in solvent as compared to that in gas phase. The electronic effect on IR spectra is distinctive. The tyrosyl fragment tends to be oxidized and the arginine moiety is easier to bind an excess electron. The variations of chemical shift and spin-spin coupling constant are more significant upon electron transfer than upon solvent dielectric constant. The augmentation of solvent dielectric constant stabilizes the system, enhances the difference of isomers, and increases the vertical ionization potential and vertical electron affinity values.
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Affiliation(s)
- Shihai Yan
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China.
| | - Lishan Yao
- Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266061, China.
| | - Baotao Kang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, China.
| | - Jin Yong Lee
- Department of Chemistry, Sungkyunkwan University, Suwon, 440746, Republic of Korea, Republic of Korea.
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Periplasmic Cytophaga hutchinsonii Endoglucanases Are Required for Use of Crystalline Cellulose as the Sole Source of Carbon and Energy. Appl Environ Microbiol 2016; 82:4835-4845. [PMID: 27260354 DOI: 10.1128/aem.01298-16] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 05/25/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The soil bacterium Cytophaga hutchinsonii actively digests crystalline cellulose by a poorly understood mechanism. Genome analyses identified nine genes predicted to encode endoglucanases with roles in this process. No predicted cellobiohydrolases, which are usually involved in the utilization of crystalline cellulose, were identified. Chromosomal deletions were performed in eight of the endoglucanase-encoding genes: cel5A, cel5B, cel5C, cel9A, cel9B, cel9C, cel9E, and cel9F Each mutant retained the ability to digest crystalline cellulose, although the deletion of cel9C caused a modest decrease in cellulose utilization. Strains with multiple deletions were constructed to identify the critical cellulases. Cells of a mutant lacking both cel5B and cel9C were completely deficient in growth on cellulose. Cell fractionation and biochemical analyses indicate that Cel5B and Cel9C are periplasmic nonprocessive endoglucanases. The requirement of periplasmic endoglucanases for cellulose utilization suggests that cellodextrins are transported across the outer membrane during this process. Bioinformatic analyses predict that Cel5A, Cel9A, Cel9B, Cel9D, and Cel9E are secreted across the outer membrane by the type IX secretion system, which has been linked to cellulose utilization. These secreted endoglucanases may perform the initial digestion within amorphous regions on the cellulose fibers, releasing oligomers that are transported into the periplasm for further digestion by Cel5B and Cel9C. The results suggest that both cell surface and periplasmic endoglucanases are required for the growth of C. hutchinsonii on cellulose and that novel cell surface proteins may solubilize and transport cellodextrins across the outer membrane. IMPORTANCE The bacterium Cytophaga hutchinsonii digests crystalline cellulose by an unknown mechanism. It lacks processive cellobiohydrolases that are often involved in cellulose digestion. Critical cellulolytic enzymes were identified by genetic analyses. Intracellular (periplasmic) nonprocessive endoglucanases performed an important role in cellulose utilization. The results suggest a model involving partial digestion at the cell surface, solubilization and uptake of cellodextrins across the outer membrane by an unknown mechanism, and further digestion within the periplasm. The ability to sequester cellodextrins and digest them intracellularly may limit losses of soluble cellobiose to other organisms. C. hutchinsonii uses an unusual approach to digest cellulose and is a potential source of novel proteins to increase the efficiency of conversion of cellulose into soluble sugars and biofuels.
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Song X, Zhang S, Wang Y, Li J, He C, Yao L. A kinetic study of Trichoderma reesei Cel7B catalyzed cellulose hydrolysis. Enzyme Microb Technol 2016; 87-88:9-16. [PMID: 27178789 DOI: 10.1016/j.enzmictec.2016.02.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 01/28/2016] [Accepted: 02/18/2016] [Indexed: 11/28/2022]
Abstract
One prominent feature of Trichoderma reesei (Tr) endoglucanases catalyzed cellulose hydrolysis is that the reaction slows down quickly after it starts (within minutes). But the mechanism of the slowdown is not well understood. A structural model of Tr- Cel7B catalytic domain bound to cellulose was built computationally and the potentially important binding residues were identified and tested experimentally. The 13 tested mutants show different binding properties in the adsorption to phosphoric acid swollen cellulose and filter paper. Though the partitioning parameter to filter paper is about 10 times smaller than that to phosphoric acid swollen cellulose, a positive correlation is shown for two substrates. The kinetic studies show that the reactions slow down quickly for both substrates. This slowdown is not correlated to the binding constant but anticorrelated to the enzyme initial activity. The amount of reducing sugars released after 24h by Cel7B in phosphoric acid swollen cellulose, Avicel and filter paper cellulose hydrolysis is correlated with the enzyme activity against a soluble substrate p-nitrophenyl lactoside. Six of the 13 tested mutants, including N47A, N52D, S99A, N323D, S324A, and S346A, yield ∼15-35% more reducing sugars than the wild type (WT) Cel7B in phosphoric acid swollen cellulose and filter paper hydrolysis. This study reveals that the slowdown of the reaction is not due to the binding of the enzyme to cellulose. The activity of Tr- Cel7B against the insoluble substrate cellulose is determined by the enzyme's capability in hydrolyzing the soluble substrate.
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Affiliation(s)
- Xiangfei Song
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Shujun Zhang
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Yefei Wang
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Jingwen Li
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Chunyan He
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Lishan Yao
- Shandong Provincial Key Laboratory of Synthetic Biology, Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China.
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Yan J, Liu W, Li Y, Lai HL, Zheng Y, Huang JW, Chen CC, Chen Y, Jin J, Li H, Guo RT. Functional and structural analysis of Pichia pastoris-expressed Aspergillus niger 1,4-β-endoglucanase. Biochem Biophys Res Commun 2016; 475:8-12. [PMID: 27154222 DOI: 10.1016/j.bbrc.2016.05.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 05/02/2016] [Indexed: 10/21/2022]
Abstract
Eukaryotic 1,4-β-endoglucanases (EC 3.2.1.4) have shown great potentials in many commercial applications because they effectively catalyze hydrolysis of cellulose, the main component of the plant cell wall. Here we expressed a glycoside hydrolase family (GH) 5 1,4-β-endoglucanase from Aspergillus niger (AnCel5A) in Pichia pastoris, which exhibits outstanding pH and heat stability. In order to further investigate the molecular mechanism of AnCel5A, apo-form and cellotetraose (CTT) complex enzyme crystal structures were solved to high resolution. AnCel5A folds into a typical (β/α)8-TIM barrel architecture, resembling other GH5 members. In the substrate binding cavity, CTT is found to bind to -4 - -1 subsites, and several polyethylene glycol molecules are found in positive subsites. In addition, several unique N-glycosylation motifs that may contribute to protein higher stability were observed from crystal structures. These results are of great importance for understanding the molecular mechanism of AnCel5A, and also provide guidance for further applications of the enzyme.
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Affiliation(s)
- Junjie Yan
- School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Weidong Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yujie Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Hui-Lin Lai
- Genozyme Biotechnology Inc., Taipei 106, Taiwan; AsiaPac Biotechnology Co., Ltd., Dongguan, 523808, China
| | - Yingying Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jian-Wen Huang
- Genozyme Biotechnology Inc., Taipei 106, Taiwan; AsiaPac Biotechnology Co., Ltd., Dongguan, 523808, China
| | - Chun-Chi Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yun Chen
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, China
| | - Jian Jin
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, China
| | - Huazhong Li
- School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Rey-Ting Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
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Liu G, Li Q, Shang N, Huang JW, Ko TP, Liu W, Zheng Y, Han X, Chen Y, Chen CC, Jin J, Guo RT. Functional and structural analyses of a 1,4-β-endoglucanase from Ganoderma lucidum. Enzyme Microb Technol 2016; 86:67-74. [DOI: 10.1016/j.enzmictec.2016.01.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 11/29/2022]
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A novel proteomics sample preparation method for secretome analysis of Hypocrea jecorina growing on insoluble substrates. J Proteomics 2016; 131:104-112. [DOI: 10.1016/j.jprot.2015.10.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 09/21/2015] [Accepted: 10/12/2015] [Indexed: 11/23/2022]
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Abstract
SUMMARY Biomass is constructed of dense recalcitrant polymeric materials: proteins, lignin, and holocellulose, a fraction constituting fibrous cellulose wrapped in hemicellulose-pectin. Bacteria and fungi are abundant in soil and forest floors, actively recycling biomass mainly by extracting sugars from holocellulose degradation. Here we review the genome-wide contents of seven Aspergillus species and unravel hundreds of gene models encoding holocellulose-degrading enzymes. Numerous apparent gene duplications followed functional evolution, grouping similar genes into smaller coherent functional families according to specialized structural features, domain organization, biochemical activity, and genus genome distribution. Aspergilli contain about 37 cellulase gene models, clustered in two mechanistic categories: 27 hydrolyze and 10 oxidize glycosidic bonds. Within the oxidative enzymes, we found two cellobiose dehydrogenases that produce oxygen radicals utilized by eight lytic polysaccharide monooxygenases that oxidize glycosidic linkages, breaking crystalline cellulose chains and making them accessible to hydrolytic enzymes. Among the hydrolases, six cellobiohydrolases with a tunnel-like structural fold embrace single crystalline cellulose chains and cooperate at nonreducing or reducing end termini, splitting off cellobiose. Five endoglucanases group into four structural families and interact randomly and internally with cellulose through an open cleft catalytic domain, and finally, seven extracellular β-glucosidases cleave cellobiose and related oligomers into glucose. Aspergilli contain, on average, 30 hemicellulase and 7 accessory gene models, distributed among 9 distinct functional categories: the backbone-attacking enzymes xylanase, mannosidase, arabinase, and xyloglucanase, the short-side-chain-removing enzymes xylan α-1,2-glucuronidase, arabinofuranosidase, and xylosidase, and the accessory enzymes acetyl xylan and feruloyl esterases.
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Huy ND, Nguyen CL, Park HS, Loc NH, Choi MS, Kim DH, Seo JW, Park SM. Characterization of a novel manganese dependent endoglucanase belongs in GH family 5 from Phanerochaete chrysosporium. J Biosci Bioeng 2015; 121:154-9. [PMID: 26173955 DOI: 10.1016/j.jbiosc.2015.06.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 05/31/2015] [Accepted: 06/18/2015] [Indexed: 01/22/2023]
Abstract
The cDNA encoding a putative glycoside hydrolase family 5, which has been predicted to be an endoglucanase (PcEg5A), was cloned from Phanerochaete chrysosporium and expressed in Pichia pastoris. PcEg5A contains a carbohydrate-binding domain and two important amino acids, E209 and E319, playing as proton donor and nucleophile in substrate catalytic domain. SDS-PAGE analysis indicated that the recombinant endoglucanase 5A (rPcEg5A) has a molecular size of 43 kDa which corresponds with the theoretical calculation. Optimum pH and temperature were found to be 4.5-6.0, and 50°C-60°C, respectively. Moreover, rPcEg5A exhibited maximal activity in the pH range of 3.0-8.0, whereas over 50% of activity still remained at 20°C and 80°C. rPcEg5A was stable at 60°C for 12 h incubation, indicating that rPcEg5A is a thermostable enzyme. Manganese ion enhanced the enzyme activity by 77%, indicating that rPcEg5A is a metal dependent enzyme. The addition of rPcEg5A to cellobiase (cellobiohydrolase and β-glucosidase) resulted in a 53% increasing saccharification of NaOH-pretreated barley straw, whereas the glucose release was 47% higher than that cellobiase treatment alone. Our study suggested that rPcEg5A is an enzyme with great potential for biomass saccharification.
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Affiliation(s)
- Nguyen Duc Huy
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Jeonbuk 570-752, Republic of Korea; Institute of Biotechnology, Hue University, Hue 530000, Viet Nam
| | - Cu Le Nguyen
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Jeonbuk 570-752, Republic of Korea
| | - Han-Sung Park
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Jeonbuk 570-752, Republic of Korea
| | | | - Myoung-Suk Choi
- Institute of Molecular Biology and Genetics, College of Natural Sciences, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Dae-Hyuk Kim
- Institute of Molecular Biology and Genetics, College of Natural Sciences, Chonbuk National University, Jeonju, Jeonbuk 561-756, Republic of Korea
| | - Jeong-Woo Seo
- Applied Microbiology Research Center, Bio-Materials Research Institute, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, Jeonbuk 580-185, Republic of Korea
| | - Seung-Moon Park
- Division of Biotechnology, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan, Jeonbuk 570-752, Republic of Korea.
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28
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Jaeger V, Burney P, Pfaendtner J. Comparison of three ionic liquid-tolerant cellulases by molecular dynamics. Biophys J 2015; 108:880-892. [PMID: 25692593 PMCID: PMC4336362 DOI: 10.1016/j.bpj.2014.12.043] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 12/20/2014] [Accepted: 12/29/2014] [Indexed: 10/24/2022] Open
Abstract
We have employed molecular dynamics to investigate the differences in ionic liquid tolerance among three distinct family 5 cellulases from Trichoderma viride, Thermogata maritima, and Pyrococcus horikoshii. Simulations of the three cellulases were conducted at a range of temperatures in various binary mixtures of the ionic liquid 1-ethyl-3-methyl-imidazolium acetate with water. Our analysis demonstrates that the effects of ionic liquids on the enzymes vary in each individual case from local structural disturbances to loss of much of one of the enzyme's secondary structure. Enzymes with more negatively charged surfaces tend to resist destabilization by ionic liquids. Specific and unique structural changes in the enzymes are induced by the presence of ionic liquids. Disruption of the secondary structure, changes in dynamical motion, and local changes in the binding pocket are observed in less tolerant enzymes. Ionic-liquid-induced denaturation of one of the enzymes is indicated over the 500 ns timescale. In contrast, the most tolerant cellulase behaves similarly in water and in ionic-liquid-containing mixtures. Unlike the heuristic approaches that attempt to predict enzyme stability using macroscopic properties, molecular dynamics allows us to predict specific atomic-level structural and dynamical changes in an enzyme's behavior induced by ionic liquids and other mixed solvents. Using these insights, we propose specific experimentally testable hypotheses regarding the origin of activity loss for each of the systems investigated in this study.
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Affiliation(s)
- Vance Jaeger
- Department of Chemical Engineering, University of Washington, Seattle, Washington
| | - Patrick Burney
- Department of Chemical Engineering, University of Washington, Seattle, Washington
| | - Jim Pfaendtner
- Department of Chemical Engineering, University of Washington, Seattle, Washington.
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29
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Payne CM, Knott BC, Mayes HB, Hansson H, Himmel ME, Sandgren M, Ståhlberg J, Beckham GT. Fungal Cellulases. Chem Rev 2015; 115:1308-448. [DOI: 10.1021/cr500351c] [Citation(s) in RCA: 533] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christina M. Payne
- Department
of Chemical and Materials Engineering and Center for Computational
Sciences, University of Kentucky, 177 F. Paul Anderson Tower, Lexington, Kentucky 40506, United States
| | - Brandon C. Knott
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
| | - Heather B. Mayes
- Department
of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States
| | - Henrik Hansson
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Michael E. Himmel
- Biosciences
Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Mats Sandgren
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Jerry Ståhlberg
- Department
of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Uppsala BioCenter, Almas allé 5, SE-75651 Uppsala, Sweden
| | - Gregg T. Beckham
- National
Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver
West Parkway, Golden, Colorado 80401, United States
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30
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He C, Chen J, An L, Wang Y, Shu Z, Yao L. Carboxyl-peptide plane stacking is important for stabilization of buried E305 of Trichoderma reesei Cel5A. J Chem Inf Model 2015; 55:104-13. [PMID: 25569819 DOI: 10.1021/ci500610m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogen bonds or salt bridges are usually formed to stabilize the buried ionizable residues. However, such interactions do not exist for two buried residues D271 and E305 of Trichoderma reesei Cel5A, an endoglucanase. Mutating D271 to alanine or leucine improves the enzyme thermostability quantified by the temperature T50 due to the elimination of the desolvation penalty of the aspartic acid. However, the same mutations for E305 decrease the enzyme thermostability. Free energy calculations based on the molecular dynamics simulation predict the thermostability of D271A, D271L, and E305A (compared to WT) in line with the experimental observation but overestimate the thermostability of E305L. Quantum mechanical calculations suggest that the carboxyl-peptide plane stacking interactions occurring to E305 but not D271 are important for the carboxyl group stabilization. For the protonated carboxyl group, the interaction energy can be as much as about -4 kcal/mol for parallel stacking and about -7 kcal/mol for T-shaped stacking. For the deprotonated carboxyl group, the largest interaction energies for parallel stacking and T-shaped stacking are comparable, about -7 kcal/mol. The solvation effect generally weakens the interaction, especially for the charged system. A search of the carboxyl-peptide plane stacking in the PDB databank indicates that parallel stacking but not T-shaped stacking is quite common, and the most probable distance between the two stacking fragments is close to the value predicted by the QM calculations. This work highlights the potential role of carboxyl amide π-π stacking in the stabilization of aspartic acid and glutamic acid in proteins.
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Affiliation(s)
- Chunyan He
- Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao 266061, China
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31
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Shu Z, Wang Y, An L, Yao L. The Slowdown of the Endoglucanase Trichoderma reesei Cel5A-Catalyzed Cellulose Hydrolysis Is Related to Its Initial Activity. Biochemistry 2014; 53:7650-8. [DOI: 10.1021/bi501059n] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Zhiyu Shu
- Laboratory
of Biofuels, Qingdao
Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Yefei Wang
- Laboratory
of Biofuels, Qingdao
Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Liaoyuan An
- Laboratory
of Biofuels, Qingdao
Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
| | - Lishan Yao
- Laboratory
of Biofuels, Qingdao
Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266061, China
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32
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Ye Z, Zheng Y, Li B, Borrusch MS, Storms R, Walton JD. Enhancement of synthetic Trichoderma-based enzyme mixtures for biomass conversion with an alternative family 5 glycosyl hydrolase from Sporotrichum thermophile. PLoS One 2014; 9:e109885. [PMID: 25295862 PMCID: PMC4190410 DOI: 10.1371/journal.pone.0109885] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 09/01/2014] [Indexed: 11/24/2022] Open
Abstract
Enzymatic conversion of lignocellulosic materials to fermentable sugars is a limiting step in the production of biofuels from biomass. We show here that combining enzymes from different microbial sources is one way to identify superior enzymes. Extracts of the thermophilic fungus Sporotrichum thermophile (synonym Myceliophthora thermophila) gave synergistic release of glucose (Glc) and xylose (Xyl) from pretreated corn stover when combined with an 8-component synthetic cocktail of enzymes from Trichoderma reesei. The S. thermophile extracts were fractionated and an enhancing factor identified as endo-β1,4-glucanase (StCel5A or EG2) of subfamily 5 of Glycosyl Hydrolase family 5 (GH5_5). In multi-component optimization experiments using a standard set of enzymes and either StCel5A or the ortholog from T. reesei (TrCel5A), reactions containing StCel5A yielded more Glc and Xyl. In a five-component optimization experiment (i.e., varying four core enzymes and the source of Cel5A), the optimal proportions for TrCel5A vs. StCel5A were similar for Glc yields, but markedly different for Xyl yields. Both enzymes were active on lichenan, glucomannan, and oat β-glucan; however, StCel5A but not TrCel5A was also active on β1,4-mannan, two types of galactomannan, and β1,4-xylan. Phylogenetically, fungal enzymes in GH5_5 sorted into two clades, with StCel5A and TrCel5A belonging to different clades. Structural differences with the potential to account for the differences in performance were deduced based on the known structure of TrCel5A and a homology-based model of StCel5A, including a loop near the active site of TrCel5A and the presence of four additional Trp residues in the active cleft of StCel5A. The results indicate that superior biomass-degrading enzymes can be identified by exploring taxonomic diversity combined with assays in the context of realistic enzyme combinations and realistic substrates. Substrate range may be a key factor contributing to superior performance within GH5_5.
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Affiliation(s)
- Zhuoliang Ye
- Department of Energy Great Lakes Bioenergy Research Center and Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
| | - Yun Zheng
- Centre for Structural and Functional Genomics, Concordia University, Montréal, Quebec, Canada
| | - Bingyao Li
- Department of Energy Great Lakes Bioenergy Research Center and Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
| | - Melissa S. Borrusch
- Department of Energy Great Lakes Bioenergy Research Center and Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
| | - Reginald Storms
- Centre for Structural and Functional Genomics, Concordia University, Montréal, Quebec, Canada
| | - Jonathan D. Walton
- Department of Energy Great Lakes Bioenergy Research Center and Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
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33
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Trudeau DL, Lee TM, Arnold FH. Engineered thermostable fungal cellulases exhibit efficient synergistic cellulose hydrolysis at elevated temperatures. Biotechnol Bioeng 2014; 111:2390-7. [DOI: 10.1002/bit.25308] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/28/2014] [Accepted: 06/02/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Devin L. Trudeau
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena California
| | - Toni M. Lee
- Division of Biology and Bioengineering; California Institute of Technology; Pasadena California
| | - Frances H. Arnold
- Division of Chemistry and Chemical Engineering; California Institute of Technology; Pasadena California
- Division of Biology and Bioengineering; California Institute of Technology; Pasadena California
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34
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Garvey M, Klinger J, Klose H, Fischer R, Commandeur U. Expression of recombinant cellulase Cel5A from Trichoderma reesei in tobacco plants. J Vis Exp 2014:51711. [PMID: 24962636 PMCID: PMC4189538 DOI: 10.3791/51711] [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] [Indexed: 10/31/2022] Open
Abstract
Cellulose degrading enzymes, cellulases, are targets of both research and industrial interests. The preponderance of these enzymes in difficult-to-culture organisms, such as hyphae-building fungi and anaerobic bacteria, has hastened the use of recombinant technologies in this field. Plant expression methods are a desirable system for large-scale production of enzymes and other industrially useful proteins. Herein, methods for the transient expression of a fungal endoglucanase, Trichoderma reesei Cel5A, in Nicotiana tabacum are demonstrated. Successful protein expression is shown, monitored by fluorescence using an mCherry-enzyme fusion protein. Additionally, a set of basic tests are used to examine the activity of transiently expressed T. reesei Cel5A, including SDS-PAGE, Western blotting, zymography, as well as fluorescence and dye-based substrate degradation assays. The system described here can be used to produce an active cellulase in a short time period, so as to assess the potential for further production in plants through constitutive or inducible expression systems.
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Affiliation(s)
- Megan Garvey
- Institute for Molecular Biotechnology, Bio7, RWTH Aachen University
| | - Johannes Klinger
- Institute for Molecular Biotechnology, Bio7, RWTH Aachen University
| | - Holger Klose
- Institute for Molecular Biotechnology, Bio7, RWTH Aachen University
| | - Rainer Fischer
- Fraunhofer Institute for Molecular Biology and Applied Ecology
| | - Ulrich Commandeur
- Institute for Molecular Biotechnology, Bio7, RWTH Aachen University;
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35
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V. Sambasivarao S, M. Granum D, Wang H, Mark Maupin C. Identifying the Enzymatic Mode of Action for Cellulase Enzymes by Means of Docking Calculations and a Machine Learning Algorithm. AIMS MOLECULAR SCIENCE 2014. [DOI: 10.3934/molsci.2014.1.59] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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36
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Garvey M, Klose H, Fischer R, Lambertz C, Commandeur U. Cellulases for biomass degradation: comparing recombinant cellulase expression platforms. Trends Biotechnol 2013; 31:581-93. [DOI: 10.1016/j.tibtech.2013.06.006] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 06/21/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
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37
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Bülbül D, Karakuş E. Production and optimization of L-glutaminase enzyme from Hypocrea jecorina pure culture. Prep Biochem Biotechnol 2013; 43:385-97. [PMID: 23464921 DOI: 10.1080/10826068.2012.741641] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
L-Glutaminase (L-glutamine amidohydrolase, EC 3.5.1.2) is the important enzyme that catalyzes the deamination of L-glutamine to L-glutamic acid and ammonium ions. Recently, L-glutaminase has received much attention with respect to its therapeutic and industrial applications. It acts as a potent antileukemic agent and shows flavor-enhancing capacity in the production of fermented foods. Glutaminase activity is widely distributed in plants, animal tissues, and microorganisms, including bacteria, yeasts, and fungi. This study presents microbial production of glutaminase enzyme from Hypocrea jecorina pure culture and determination of optimum conditions and calculation of kinetic parameters of the produced enzyme. The optimum values were determined by using sa Nesslerization reaction for our produced glutaminase enzyme. The optimum pH value was determined as 8.0 and optimum temperature as 50°C for the glutaminase enzyme. The Km and Vmax values, the kinetic parameters, of enzyme produced from Hypocrea jecorina, pure culture were determined as 0.491 mM for Km and 13.86 U/L for Vmax by plotted Lineweaver-Burk graphing, respectively. The glutaminase enzyme from H. jecorina microorganism has very high thermal and storage stability.
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Affiliation(s)
- Dilara Bülbül
- Department of Chemistry, Yildiz Technical University, İstanbul, Turkey
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38
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Delsaute M, Berlemont R, Dehareng D, Van Elder D, Galleni M, Bauvois C. Three-dimensional structure of RBcel1, a metagenome-derived psychrotolerant family GH5 endoglucanase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2013; 69:828-33. [PMID: 23908022 PMCID: PMC3729153 DOI: 10.1107/s1744309113014565] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 05/27/2013] [Indexed: 11/10/2022]
Abstract
RBcel1 is an endoglucanase belonging to glycoside hydrolase family 5 subfamily 5 (GH5_5) that was recently identified from a soil metagenome library from the Antarctic. Unlike its closest structural homologue (Cel5A from Thermoascus aurantiacus), this enzyme was reported to be able to catalyze transglycosylation reactions and has putatively been implicated in the bacterial cellulose-synthesis process. Here, the structure of RBcel1 at 1.4 Å resolution, solved by molecular replacement, is reported. The structure and putative substrate-binding site are described and compared with those of other GH5_5 subfamily members.
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Affiliation(s)
- Maud Delsaute
- Centre d’Ingénierie des Protéines, Laboratoire de Macromolécules Biologiques, Université de Liège (ULg), Bâtiment B6, Allée de la Chimie 3, 4000 Liège, Belgium
| | - Renaud Berlemont
- Centre d’Ingénierie des Protéines, Laboratoire de Macromolécules Biologiques, Université de Liège (ULg), Bâtiment B6, Allée de la Chimie 3, 4000 Liège, Belgium
- Department of Earth System Science and Department of Evolutionary Biology, University of California Irvine, 3208 Croul Hall, Irvine, CA 92617, USA
| | - Dominique Dehareng
- Centre d’Ingénierie des Protéines, Cristallographie des Macromolécules Biologiques, Université de Liège (ULg), Bâtiment B6, Allée de la Chimie 3, 4000 Liège, Belgium
| | - Dany Van Elder
- Laboratoire de Microbiologie, Université Libre de Bruxelles (ULB), Campus CERIA – Avenue E. Gryson 1, 1070 Bruxelles, Belgium
| | - Moreno Galleni
- Centre d’Ingénierie des Protéines, Laboratoire de Macromolécules Biologiques, Université de Liège (ULg), Bâtiment B6, Allée de la Chimie 3, 4000 Liège, Belgium
| | - Cédric Bauvois
- Unité de Cristallographie des Protéines, Institut de Recherches Microbiologiques J.-M. Wiame (IRMW) – Commission Communautaire Française (CoCoF), Campus CERIA – Avenue E. Gryson 1, 1070 Bruxelles, Belgium
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39
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Insights into exo- and endoglucanase activities of family 6 glycoside hydrolases from Podospora anserina. Appl Environ Microbiol 2013; 79:4220-9. [PMID: 23645193 DOI: 10.1128/aem.00327-13] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The ascomycete Podospora anserina is a coprophilous fungus that grows at late stages on droppings of herbivores. Its genome encodes a large diversity of carbohydrate-active enzymes. Among them, four genes encode glycoside hydrolases from family 6 (GH6), the members of which comprise putative endoglucanases and exoglucanases, some of them exerting important functions for biomass degradation in fungi. Therefore, this family was selected for functional analysis. Three of the enzymes, P. anserina Cel6A (PaCel6A), PaCel6B, and PaCel6C, were functionally expressed in the yeast Pichia pastoris. All three GH6 enzymes hydrolyzed crystalline and amorphous cellulose but were inactive on hydroxyethyl cellulose, mannan, galactomannan, xyloglucan, arabinoxylan, arabinan, xylan, and pectin. PaCel6A had a catalytic efficiency on cellotetraose comparable to that of Trichoderma reesei Cel6A (TrCel6A), but PaCel6B and PaCel6C were clearly less efficient. PaCel6A was the enzyme with the highest stability at 45°C, while PaCel6C was the least stable enzyme, losing more than 50% of its activity after incubation at temperatures above 30°C for 24 h. In contrast to TrCel6A, all three studied P. anserina GH6 cellulases were stable over a wide range of pHs and conserved high activity at pH values of up to 9. Each enzyme displayed a distinct substrate and product profile, highlighting different modes of action, with PaCel6A being the enzyme most similar to TrCel6A. PaCel6B was the only enzyme with higher specific activity on carboxymethylcellulose (CMC) than on Avicel and showed lower processivity than the others. Structural modeling predicts an open catalytic cleft, suggesting that PaCel6B is an endoglucanase.
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