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de Andrades D, Alnoch RC, Alves GS, Salgado JCS, Almeida PZ, Berto GL, Segato F, Ward RJ, Buckeridge MS, Polizeli MDLTM. Recombinant GH3 β-glucosidase stimulated by xylose and tolerant to furfural and 5-hydroxymethylfurfural obtained from Aspergillus nidulans. BIORESOUR BIOPROCESS 2024; 11:77. [PMID: 39073555 PMCID: PMC11286919 DOI: 10.1186/s40643-024-00784-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 07/03/2024] [Indexed: 07/30/2024] Open
Abstract
The β-glucosidase gene from Aspergillus nidulans FGSC A4 was cloned and overexpressed in the A. nidulans A773. The resulting purified β-glucosidase, named AnGH3, is a monomeric enzyme with a molecular weight of approximately 80 kDa, as confirmed by SDS-PAGE. Circular dichroism further validated its unique canonical barrel fold (β/α), a feature also observed in the 3D homology model of AnGH3. The most striking aspect of this recombinant enzyme is its robustness, as it retained 100% activity after 24 h of incubation at 45 and 50 ºC and pH 6.0. Even at 55 °C, it maintained 72% of its enzymatic activity after 6 h of incubation at the same pH. The kinetic parameters Vmax, KM, and Kcat/KM for ρ-nitrophenyl-β-D-glucopyranoside (ρNPG) and cellobiose were also determined. Using ρNPG, the enzyme demonstrated a Vmax of 212 U mg - 1, KM of 0.0607 mmol L - 1, and Kcat/KM of 4521 mmol L - 1 s - 1 when incubated at pH 6.0 and 65 °C. The KM, Vmax, and Kcat/KM using cellobiose were 2.7 mmol L - 1, 57 U mg - 1, and 27 mmol -1 s - 1, respectively. AnGH3 activity was significantly enhanced by xylose and ethanol at concentrations up to 1.5 mol L - 1 and 25%, respectively. Even in challenging conditions, at 65 °C and pH 6.0, the enzyme maintained its activity, retaining 100% and 70% of its initial activity in the presence of 200 mmol L - 1 furfural and 5-hydroxymethylfurfural (HMF), respectively. The potential of this enzyme was further demonstrated by its application in the saccharification of the forage grass Panicum maximum, where it led to a 48% increase in glucose release after 24 h. These unique characteristics, including high catalytic performance, good thermal stability in hydrolysis temperature, and tolerance to elevated concentrations of ethanol, D-xylose, furfural, and HMF, position this recombinant enzyme as a promising tool in the hydrolysis of lignocellulosic biomass as part of an efficient multi-enzyme cocktail, thereby opening new avenues in the field of biotechnology and enzymology.
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Affiliation(s)
- Diandra de Andrades
- Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Robson C Alnoch
- Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Gabriela S Alves
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
- Laboratory of Enzymology and Molecular Biology of Microorganisms, Institute of Biology, Campinas State University (UNICAMP), Campinas, 13083-970, SP, Brazil
| | - Jose C S Salgado
- Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | - Paula Z Almeida
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
| | - Gabriela Leila Berto
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, 12602-810, Brazil
| | - Fernando Segato
- Department of Biotechnology, Lorena School of Engineering, University of São Paulo, Lorena, 12602-810, Brazil
| | - Richard J Ward
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil
| | | | - Maria de Lourdes T M Polizeli
- Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14040-901, Brazil.
- Department of Biochemistry and Immunology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil.
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Hu C, Wang Y, Wang W, Cui W, Jia X, Mayo KH, Zhou Y, Su J, Yuan Y. A trapped covalent intermediate as a key catalytic element in the hydrolysis of a GH3 β-glucosidase: An X-ray crystallographic and biochemical study. Int J Biol Macromol 2024; 265:131131. [PMID: 38527679 DOI: 10.1016/j.ijbiomac.2024.131131] [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: 01/10/2024] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 03/27/2024]
Abstract
Glycoside hydrolases (GHs) are industrially important enzymes that hydrolyze glycosidic bonds in glycoconjugates. In this study, we found a GH3 β-glucosidase (CcBgl3B) from Cellulosimicrobium cellulans sp. 21 was able to selectively hydrolyze the β-1,6-glucosidic bond linked glucose of ginsenosides. X-ray crystallographic studies of the ligand complex ginsenoside-specific β-glucosidase provided a novel finding that support the catalytic mechanism of GH3. The substrate was clearly identified within the catalytic center of wild-type CcBgl3B, revealing that the C1 atom of the glucose was covalently bound to the Oδ1 group of the conserved catalytic nucleophile Asp264 as an enzyme-glycosyl intermediate. The glycosylated Asp264 could be identified by mass spectrometry. Through site-directed mutagenesis studies with Asp264, it was found that the covalent intermediate state formed by Asp264 and the substrate was critical for catalysis. In addition, Glu525 variants (E525A, E525Q and E525D) showed no or marginal activity against pNPβGlc; thus, this residue could supply a proton for the reaction. Overall, our study provides an insight into the catalytic mechanism of the GH3 enzyme CcBgl3B.
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Affiliation(s)
- Chenxing Hu
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Yibing Wang
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Weiyang Wang
- College of Life Science and Technology, Changchun University of Science & Technology, Changchun, Jilin 130022, China
| | - Wanli Cui
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Xinyue Jia
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Kevin H Mayo
- Department of Biochemistry, Molecular Biology & Biophysics, 6-155 Jackson Hall, University of Minnesota, Minneapolis, MN 55455, USA
| | - Yifa Zhou
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China
| | - Jiyong Su
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
| | - Ye Yuan
- Engineering Research Center of Glycoconjugates Ministry of Education, Jilin Provincial Key Laboratory of Chemistry and Biology of Changbai Mountain Natural Drugs, School of Life Sciences, Northeast Normal University, Changchun 130024, China.
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3
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Yao Q, Xu J, Tang N, Chen W, Gu Q, Li H. Screening, cloning, immobilization and application prospects of a novel β-glucosidase from the soil metagenome. ENVIRONMENTAL RESEARCH 2024; 244:117676. [PMID: 37996002 DOI: 10.1016/j.envres.2023.117676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/11/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023]
Abstract
The soil environment for straw return is a rich and valuable library containing many microorganisms and proteins. In this study, we aimed to screen a high-quality β-glucosidase (BGL) from the soil metagenomic library and to overcome the limitation of the low extraction rate of resveratrol in Polygonum cuspidatum. This includes the construction of a soil metagenomic library, screening of BGL, bioinformatics analysis, cloning, expression, immobilization, enzymatic property analysis, and application for the transformation of polydatin. The results showed that the soil metagenomic library of straw return was successfully constructed, and a novel BGL was screened. The identified 1356 bp long BGL belonged to the glycoside hydrolase 1 (GH1) family and was named Bgl1356. After successful cloning and expression of Bgl1356, it was immobilized using chitosan. The optimum temperature of immobilized Bgl1356 was 50 °C, and the pH was 5. It exhibited good tolerance for various metal ions (CO2+, Ni2+, Cu2+, Mn2+, Na2+, Ca2+, and Ag+) and organic solvents (DMSO, Triton-X-10, and ethanol). Enzymatic kinetics assays showed that Bgl1356 had good affinity for the substrate, and the specific enzyme activity was 234.03 U/mg. The conversion rate of polydatin by immobilized Bgl1356 was 95.70 ± 1.08%, facilitating the production of high amounts of resveratrol. Thus, this paper reports a novel temperature-, organic solvent-, and metal ion-tolerant BGL that has good application prospects in the pharmaceutical industry.
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Affiliation(s)
- Qian Yao
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China; Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, 510006, China.
| | - Jin Xu
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China; Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, 510006, China.
| | - Nan Tang
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
| | - Weiji Chen
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
| | - Quliang Gu
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
| | - He Li
- School of Basic Medical Sciences, Guangdong Pharmaceutical University, Guangzhou, 510006, China; Guangdong Key Laboratory of Bioactive Drug Research, Guangzhou, 510006, China.
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4
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Hobbs EEM, Gloster TM, Pritchard L. cazy_webscraper: local compilation and interrogation of comprehensive CAZyme datasets. Microb Genom 2023; 9:mgen001086. [PMID: 37578822 PMCID: PMC10483417 DOI: 10.1099/mgen.0.001086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/23/2023] [Indexed: 08/15/2023] Open
Abstract
Carbohydrate active enzymes (CAZymes) are pivotal in biological processes including energy metabolism, cell structure maintenance, signalling, and pathogen recognition. Bioinformatic prediction and mining of CAZymes improves our understanding of these activities and enables discovery of candidates of interest for industrial biotechnology, particularly the processing of organic waste for biofuel production. CAZy (www.cazy.org) is a high-quality, manually curated, and authoritative database of CAZymes that is often the starting point for these analyses. Automated querying and integration of CAZy data with other public datasets would constitute a powerful resource for mining and exploring CAZyme diversity. However, CAZy does not itself provide methods to automate queries, or integrate annotation data from other sources (except by following hyperlinks) to support further analysis. To overcome these limitations we developed cazy_webscraper, a command-line tool that retrieves data from CAZy and other online resources to build a local, shareable and reproducible database that augments and extends the authoritative CAZy database. cazy_webscraper's integration of curated CAZyme annotations with their corresponding protein sequences, up-to-date taxonomy assignments, and protein structure data facilitates automated large-scale and targeted bioinformatic CAZyme family analysis and candidate screening. This tool has found widespread uptake in the community, with over 35 000 downloads (from April 2021 to June 2023). We demonstrate the use and application of cazy_webscraper to: (i) augment, update and correct CAZy database accessions; (ii) explore the taxonomic distribution of CAZymes recorded in CAZy, identifying under-represented taxa and unusual CAZy class distributions; and (iii) investigate three CAZymes having potential biotechnological application for degradation of biomass, but lacking a representative structure in the PDB database. We describe in general how cazy_webscraper facilitates functional, structural and evolutionary studies to aid identification of candidate enzymes for further characterization, and specifically note that CAZy provides supporting evidence for recent expansion of the Auxiliary Activities (AA) CAZy family in eukaryotes, consistent with functions potentially specific to eukaryotic lifestyles.
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Affiliation(s)
- Emma E. M. Hobbs
- School of Biology and Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, G4 0RE, UK
- Cell and Molecular Sciences, James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK
| | - Tracey M. Gloster
- School of Biology and Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Leighton Pritchard
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, G4 0RE, UK
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Ouyang B, Wang G, Zhang N, Zuo J, Huang Y, Zhao X. Recent Advances in β-Glucosidase Sequence and Structure Engineering: A Brief Review. Molecules 2023; 28:4990. [PMID: 37446652 DOI: 10.3390/molecules28134990] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/21/2023] [Accepted: 06/23/2023] [Indexed: 07/15/2023] Open
Abstract
β-glucosidases (BGLs) play a crucial role in the degradation of lignocellulosic biomass as well as in industrial applications such as pharmaceuticals, foods, and flavors. However, the application of BGLs has been largely hindered by issues such as low enzyme activity, product inhibition, low stability, etc. Many approaches have been developed to engineer BGLs to improve these enzymatic characteristics to facilitate industrial production. In this article, we review the recent advances in BGL engineering in the field, including the efforts from our laboratory. We summarize and discuss the BGL engineering studies according to the targeted functions as well as the specific strategies used for BGL engineering.
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Affiliation(s)
- Bei Ouyang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Guoping Wang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Nian Zhang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Jiali Zuo
- School of Computer and Information Engineering, Jiangxi Normal University, Nanchang 330022, China
| | - Yunhong Huang
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
| | - Xihua Zhao
- College of Life Science, Jiangxi Normal University, Nanchang 330022, China
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6
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Singh N, Sithole B, Govinden R. Screening for cellulases and preliminary optimisation of glucose tolerant β-glucosidase production and characterisation. Mycology 2022; 14:91-107. [PMID: 37152851 PMCID: PMC10161942 DOI: 10.1080/21501203.2022.2155261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The search for a novel microbial producer of cellulases including a glucose tolerant β-glucosidase is a challenge as most are inhibited by their product glucose. This study aims to screen for cellulolytic fungi using qualitative and quantitative screening methods. Primary screening revealed 34 of 46 fungal isolates with β-glucosidase activity. Eleven and 13 of these also displayed endoglucanase and exoglucanase activities, respectively. During secondary screening, this number was reduced to 26 β-glucosidase producers with 13 also having endoglucanase and exoglucanase activities. Isolate C1 displayed enhanced production of β-glucosidases in the presence of 0.05 M glucose (69% higher activity). Optimisation of growth conditions for β-glucosidase production by one variable at a time experiments improved production for (isolates) PS1 (64%), MB5 (84%), and C2 (69%). Isolate PS1 identified as Chaetomella sp. BBA70074 displayed the highest tolerance to glucose, retaining 10% of β-glucosidase activity in the presence of 0.8 M glucose. Tolerance to glucose increased to 14% when produced under optimal conditions. β-Glucosidase had a molecular weight of 170 kDa with a pH and temperature optima of 6 and 70°C, respectively. Future studies will include optimisation of the production of the glucose tolerant enzyme by Chaetomella sp. BBA70074.
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Affiliation(s)
- Nivisti Singh
- Discipline of Microbiology, School of Life Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Bruce Sithole
- Discipline of Engineering, Howard Campus, University of KwaZulu-Natal, Durban, South Africa
- Biorefinery Industry Development Facility, Council for Scientific and Industrial Research, Durban, South Africa
| | - Roshini Govinden
- Discipline of Microbiology, School of Life Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
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Evaluating Enzymatic Productivity—The Missing Link to Enzyme Utility. Int J Mol Sci 2022; 23:ijms23136908. [PMID: 35805910 PMCID: PMC9266678 DOI: 10.3390/ijms23136908] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 06/19/2022] [Accepted: 06/20/2022] [Indexed: 01/07/2023] Open
Abstract
Kinetic productivity analysis is critical to the characterization of enzyme catalytic performance and capacity. However, productivity analysis has been largely overlooked in the published literature. Less than 0.01% of studies which report on enzyme characterization present productivity analysis, despite the fact that this is the only measurement method that provides a reliable indicator of potential commercial utility. Here, we argue that reporting productivity data involving native, modified, and immobilized enzymes under different reaction conditions will be of immense value in optimizing enzymatic processes, with a view to accelerating biotechnological applications. With the use of examples from wide-ranging studies, we demonstrate that productivity is a measure of critical importance to the translational and commercial use of enzymes and processes that employ them. We conclude the review by suggesting steps to maximize the productivity of enzyme catalyzed reactions.
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8
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Ye TJ, Huang KF, Ko TP, Wu SH. Synergic action of an inserted carbohydrate-binding module in a glycoside hydrolase family 5 endoglucanase. Acta Crystallogr D Struct Biol 2022; 78:633-646. [PMID: 35503211 PMCID: PMC9063844 DOI: 10.1107/s2059798322002601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/07/2022] [Indexed: 11/24/2022] Open
Abstract
A unique endoglucanase with a carbohydrate-binding module inserted in the middle of the catalytic domain has been characterized structurally and functionally, providing insights into the mode of action responsible for its enhanced catalytic performance. Most known cellulase-associated carbohydrate-binding modules (CBMs) are attached to the N- or C-terminus of the enzyme or are expressed separately and assembled into multi-enzyme complexes (for example to form cellulosomes), rather than being an insertion into the catalytic domain. Here, by solving the crystal structure, it is shown that MtGlu5 from Meiothermus taiwanensis WR-220, a GH5-family endo-β-1,4-glucanase (EC 3.2.1.4), has a bipartite architecture consisting of a Cel5A-like catalytic domain with a (β/α)8 TIM-barrel fold and an inserted CBM29-like noncatalytic domain with a β-jelly-roll fold. Deletion of the CBM significantly reduced the catalytic efficiency of MtGlu5, as determined by isothermal titration calorimetry using inactive mutants of full-length and CBM-deleted MtGlu5 proteins. Conversely, insertion of the CBM from MtGlu5 into TmCel5A from Thermotoga maritima greatly enhanced the substrate affinity of TmCel5A. Bound sugars observed between two tryptophan side chains in the catalytic domains of active full-length and CBM-deleted MtGlu5 suggest an important stacking force. The synergistic action of the catalytic domain and CBM of MtGlu5 in binding to single-chain polysaccharides was visualized by substrate modeling, in which additional surface tryptophan residues were identified in a cross-domain groove. Subsequent site-specific mutagenesis results confirmed the pivotal role of several other tryptophan residues from both domains of MtGlu5 in substrate binding. These findings reveal a way to incorporate a CBM into the catalytic domain of an existing enzyme to make a robust cellulase.
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Ku JT, Chen AY, Lan EI. Metabolic engineering of Escherichia coli for efficient biosynthesis of butyl acetate. Microb Cell Fact 2022; 21:28. [PMID: 35193559 PMCID: PMC8864926 DOI: 10.1186/s12934-022-01755-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 02/07/2022] [Indexed: 11/30/2022] Open
Abstract
Background Butyl acetate is a versatile compound that is widely used in the chemical and food industry. The conventional butyl acetate synthesis via Fischer esterification of butanol and acetic acid using catalytic strong acids under high temperature is not environmentally benign. Alternative lipase-catalyzed ester formation requires a significant amount of organic solvent which also presents another environmental challenge. Therefore, a microbial cell factory capable of producing butyl acetate through fermentation of renewable resources would provide a greener approach to butyl acetate production. Result Here, we developed a metabolically engineered strain of Escherichia coli that efficiently converts glucose to butyl acetate. A modified Clostridium CoA-dependent butanol production pathway was used to synthesize butanol which was then condensed with acetyl-CoA through an alcohol acetyltransferase. Optimization of alcohol acetyltransferase expression and redox balance with auto-inducible fermentative controlled gene expression led to an effective titer of 22.8 ± 1.8 g/L butyl acetate produced in a bench-top bioreactor. Conclusion Building on the well-developed Clostridium CoA-dependent butanol biosynthetic pathway, expression of an alcohol acetyltransferase converts the butanol produced into butyl acetate. The results from this study provided a strain of E. coli capable of directly producing butyl acetate from renewable resources at ambient conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01755-y.
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Affiliation(s)
- Jason T Ku
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Arvin Y Chen
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.,Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan
| | - Ethan I Lan
- Department of Biological Science and Technology, National Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan. .,Department of Biological Science and Technology, National Yang Ming Chiao Tung University, 1001 Daxue Road, Hsinchu City, 300, Taiwan.
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10
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Peng ZQ, Li C, Lin Y, Wu SS, Gan LH, Liu J, Yang SL, Zeng XH, Lin L. Cellulase production and efficient saccharification of biomass by a new mutant Trichoderma afroharzianum MEA-12. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:219. [PMID: 34809676 PMCID: PMC8607671 DOI: 10.1186/s13068-021-02072-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 11/10/2021] [Indexed: 06/01/2023]
Abstract
BACKGROUND Cellulase plays a key role in converting cellulosic biomass into fermentable sugar to produce chemicals and fuels, which is generally produced by filamentous fungi. However, most of the filamentous fungi obtained by natural breeding have low secretory capacity in cellulase production, which are far from meeting the requirements of industrial production. Random mutagenesis combined with adaptive laboratory evolution (ALE) strategy is an effective method to increase the production of fungal enzymes. RESULTS This study obtained a mutant of Trichoderma afroharzianum by exposures to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), Ethyl Methanesulfonate (EMS), Atmospheric and Room Temperature Plasma (ARTP) and ALE with high sugar stress. The T. afroharzianum mutant MEA-12 produced 0.60, 5.47, 0.31 and 2.17 IU/mL FPase, CMCase, pNPCase and pNPGase, respectively. These levels were 4.33, 6.37, 4.92 and 4.15 times higher than those of the parental strain, respectively. Also, it was found that T. afroharzianum had the same carbon catabolite repression (CCR) effect as other Trichoderma in liquid submerged fermentation. In contrast, the mutant MEA-12 can tolerate the inhibition of glucose (up to 20 mM) without affecting enzyme production under inducing conditions. Interestingly, crude enzyme from MEA-12 showed high enzymatic hydrolysis efficiency against three different biomasses (cornstalk, bamboo and reed), when combined with cellulase from T. reesei Rut-C30. In addition, the factors that improved cellulase production by MEA-12 were clarified. CONCLUSIONS Overall, compound mutagenesis combined with ALE effectively increased the production of fungal cellulase. A super-producing mutant MEA-12 was obtained, and its cellulase could hydrolyze common biomasses efficiently, in combination with enzymes derived from model strain T. reesei, which provides a new choice for processing of bioresources in the future.
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Affiliation(s)
- Zhi-Qing Peng
- College of Energy, Xiamen University, Xiamen, 361102, China
| | - Chuang Li
- College of Energy, Xiamen University, Xiamen, 361102, China
| | - Yi Lin
- College of Energy, Xiamen University, Xiamen, 361102, China
| | - Sheng-Shan Wu
- College of Energy, Xiamen University, Xiamen, 361102, China
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China
| | - Li-Hui Gan
- College of Energy, Xiamen University, Xiamen, 361102, China
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China
| | - Jian Liu
- College of Energy, Xiamen University, Xiamen, 361102, China
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China
| | - Shu-Liang Yang
- College of Energy, Xiamen University, Xiamen, 361102, China
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China
| | - Xian-Hai Zeng
- College of Energy, Xiamen University, Xiamen, 361102, China.
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China.
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China.
| | - Lu Lin
- College of Energy, Xiamen University, Xiamen, 361102, China
- Fujian Engineering and Research Centre of Clean and High-Valued Technologies for Biomass, Xiamen, 361102, China
- Xiamen Key Laboratory of Clean and High-Valued Utilization for Biomass, Xiamen, 361102, China
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Kao MR, Yu SM, Ho THUD. Improvements of the productivity and saccharification efficiency of the cellulolytic β-glucosidase D2-BGL in Pichia pastoris via directed evolution. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:126. [PMID: 34059121 PMCID: PMC8166090 DOI: 10.1186/s13068-021-01973-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/17/2021] [Indexed: 05/02/2023]
Abstract
BACKGROUND β-Glucosidases are essential for cellulose hydrolysis by catalyzing the final cellulolytic degradation of cello-oligomers and cellobiose to glucose. D2-BGL is a fungal glycoside hydrolase family 3 (GH3) β-glucosidase isolated from Chaetomella raphigera with high substrate affinity, and is an efficient β-glucosidase supplement to Trichoderma reesei cellulase mixtures for the saccharification of lignocellulosic biomass. RESULTS We have carried out error-prone PCR to further increase catalytic efficiency of wild-type (WT) D2-BGL. Three mutants, each with substitution of two amino acids on D2-BGL, exhibited increased activity in a preliminary mutant screening in Saccharomyces cerevisiae. Effects of single amino acid replacements on catalysis efficiency and enzyme production have been investigated by subsequent expression in Pichia pastoris. Substitution F256M resulted in enhancing the tolerance to substrate inhibition and specific activity, and substitution D224G resulted in increasing the production of recombinant enzyme. The best D2-BGL mutant generated, Mut M, was constructed by combining beneficial mutations D224G, F256M and Y260D. Expression of Mut M in Pichia pastoris resulted in 2.7-fold higher production of recombinant protein, higher Vmax and greater substrate inhibition tolerance towards cellobiose relative to wild-type enzyme. Surprisingly, Mut M overexpression induced the ER unfolded protein response to a level lower than that with WT D2 overexpression in P. pastoris. When combined with the T. reesei cellulase preparation Celluclast 1.5L, Mut M hydrolyzed acid-pretreated sugarcane bagasse more efficiently than WT D2. CONCLUSIONS D2-BGL mutant Mut M was generated successfully by following directed evolution approach. Mut M carries three mutations that are not reported in other directed evolution studies of GH3 β-glucosidases, and this mutant exhibited greater tolerance to substrate inhibition and higher Vmax than wild-type enzyme. Besides the enhanced specific activity, Mut M also exhibited a higher protein titer than WT D2 when it was overexpressed in P. pastoris. Our study demonstrates that both catalytic efficiency and productivity of a cellulolytic enzyme can be enhanced via protein engineering.
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Affiliation(s)
- Mu-Rong Kao
- Molecular and Cell Biology, Taiwan International Graduate Program, Academia Sinica and National Defense Medical Center, Taipei, 115 Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- Department of Plant Pathology, National Chung Hsing University, Taichung, 402 Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung, 402 Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402 Taiwan
| | - Tuan-H ua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 115 Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, 402 Taiwan
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Lin MC, Kuo HW, Kao MR, Lin WD, Li CW, Hung KS, Yang SC, Yu SM, Ho THD. From simple and specific zymographic detections to the annotation of a fungus Daldinia caldariorum D263 that encodes a wide range of highly bioactive cellulolytic enzymes. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:120. [PMID: 34020690 PMCID: PMC8140500 DOI: 10.1186/s13068-021-01959-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 04/20/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Lignocellulolytic enzymes are essential for agricultural waste disposal and production of renewable bioenergy. Many commercialized cellulase mixtures have been developed, mostly from saprophytic or endophytic fungal species. The cost of complete cellulose digestion is considerable because a wide range of cellulolytic enzymes is needed. However, most fungi can only produce limited range of highly bioactive cellulolytic enzymes. We aimed to investigate a simple yet specific method for discovering unique enzymes so that fungal species producing a diverse group of cellulolytic enzymes can be identified. RESULTS The culture medium of an endophytic fungus, Daldinia caldariorum D263, contained a complete set of cellulolytic enzymes capable of effectively digesting cellulose residues into glucose. By taking advantage of the unique product inhibition property of β-glucosidases, we have established an improved zymography method that can easily distinguish β-glucosidase and exoglucanase activity. Our zymography method revealed that D263 can secrete a wide range of highly bioactive cellulases. Analyzing the assembled genome of D263, we found over 100 potential genes for cellulolytic enzymes that are distinct from those of the commercially used fungal species Trichoderma reesei and Aspergillus niger. We further identified several of these cellulolytic enzymes by mass spectrometry. CONCLUSIONS The genome of Daldinia caldariorum D263 has been sequenced and annotated taking advantage of a simple yet specific zymography method followed by mass spectrometry analysis, and it appears to encode and secrete a wide range of bioactive cellulolytic enzymes. The genome and cellulolytic enzyme secretion of this unique endophytic fungus should be of value for identifying active cellulolytic enzymes that can facilitate conversion of agricultural wastes to fermentable sugars for the industrial production of biofuels.
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Affiliation(s)
- Meng-Chun Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Hsion-Wen Kuo
- Department of Environmental Science and Engineering, Tunghai University, Taichung, Taiwan, ROC
| | - Mu-Rong Kao
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Wen-Dar Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Chen-Wei Li
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Kuo-Sheng Hung
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC
| | - Sheng-Chih Yang
- Institute of Tropical Plant Science, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, ROC
- Biotechnology Research Center, National Chung Hsing University, Taichung, Taiwan, ROC
| | - Tuan-Hua David Ho
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan, ROC.
- Biotechnology Research Center, National Chung Hsing University, Taichung, Taiwan, ROC.
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13
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Lima RAT, De Oliveira G, Souza AA, Lopes FAC, Santana RH, Istvan P, Quirino BF, Barbosa J, De Freitas S, Garay AV, Krüger RH. Functional and structural characterization of a novel GH3 β-glucosidase from the gut metagenome of the Brazilian Cerrado termite Syntermes wheeleri. Int J Biol Macromol 2020; 165:822-834. [PMID: 33011259 DOI: 10.1016/j.ijbiomac.2020.09.236] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/24/2020] [Accepted: 09/25/2020] [Indexed: 12/26/2022]
Abstract
In this study, a GH3 family β-glucosidase (Bgl7226) from metagenomic sequences of the Syntermes wheeleri gut, a Brazilian Cerrado termite, was expressed, purified and characterized. The enzyme showed two optimum pHs (pH 7 and pH 10), and a maximum optimum temperature of about 40 °C using 4-Nitrophenyl β-D-glucopyranoside (pNPG) as substrate. Bgl7226 showed higher enzymatic activity at basic pH, but higher affinity (Km) at neutral pH. However, at neutral pH the Bgl7226 enzyme showed higher catalytic efficiency (kcat/Km) for pNPG substrate. Predictive analysis about the enzyme structure-function relationship by sequence alignment suggested the presence of multi-domains and conserved catalytic sites. Circular dichroism results showed that the secondary structure composition of the enzyme is pH-dependent. Small conformational changes occurred close to the optimum temperature of 40 o C, and seem important for the highest activity of Bgl7226 observed at pH 7 and 10. In addition, the small transition in the unfolding curves close to 40 o C is typical of intermediates associated with proteins structured in several domains. Bgl7226 has significant β-glucosidase activity which could be attractive for biotechnological applications, such as plant roots detoxification; specifically, our group is interested in cassava roots (Manihot esculenta) detoxification.
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Affiliation(s)
| | - Gideane De Oliveira
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil
| | - Amanda Araújo Souza
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil
| | | | - Renata Henrique Santana
- Instituto Federal de Brasília, Planaltina Campus, Brasília, DF 70910-900, Brazil; Genomic Sciences and Biotechnology, Universidade Católica de Brasília, Brasília, DF 70790-160, Brazil
| | - Paula Istvan
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil; Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben- Gurion University of the Negev, Department of Environmental Hydrology & Microbiology, Israel
| | - Betania Ferraz Quirino
- Embrapa Agroenergy, Parque Estação Biológica (PqEB), PqEB s/n°, Brasília, DF 70770-901, Brazil
| | - João Barbosa
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil
| | - Sonia De Freitas
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil
| | - Aisel Valle Garay
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil
| | - Ricardo Henrique Krüger
- Department of Cell Biology, Darcy Ribeiro Campus, Universidade de Brasília, Brasília, DF 70910-900, Brazil.
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Simmons CR, MacCulloch T, Zhang F, Liu Y, Stephanopoulos N, Yan H. A Self-Assembled Rhombohedral DNA Crystal Scaffold with Tunable Cavity Sizes and High-Resolution Structural Detail. Angew Chem Int Ed Engl 2020; 59:18619-18626. [PMID: 32533629 DOI: 10.1002/anie.202005505] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Indexed: 11/08/2022]
Abstract
DNA is an ideal molecule for the construction of 3D crystals with tunable properties owing to its high programmability based on canonical Watson-Crick base pairing, with crystal assembly in all three dimensions facilitated by immobile Holliday junctions and sticky end cohesion. Despite the promise of these systems, only a handful of unique crystal scaffolds have been reported. Herein, we describe a new crystal system with a repeating sequence that mediates the assembly of a 3D scaffold via a series of Holliday junctions linked together with complementary sticky ends. By using an optimized junction sequence, we could determine a high-resolution (2.7 Å) structure containing R3 crystal symmetry, with a slight subsequent improvement (2.6 Å) using a modified sticky-end sequence. The immobile Holliday junction sequence allowed us to produce crystals that provided unprecedented atomic detail. In addition, we expanded the crystal cavities by 50 % by adding an additional helical turn between junctions, and we solved the structure to 4.5 Å resolution by molecular replacement.
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Affiliation(s)
- Chad R Simmons
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Tara MacCulloch
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Fei Zhang
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Yan Liu
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Nicholas Stephanopoulos
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Hao Yan
- Biodesign Center for Molecular Design and Biomimetics, Arizona State University, USA.,School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA
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15
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Simmons CR, MacCulloch T, Zhang F, Liu Y, Stephanopoulos N, Yan H. A Self‐Assembled Rhombohedral DNA Crystal Scaffold with Tunable Cavity Sizes and High‐Resolution Structural Detail. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202005505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chad R. Simmons
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
| | - Tara MacCulloch
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
| | - Fei Zhang
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
| | - Yan Liu
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
| | - Nicholas Stephanopoulos
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
| | - Hao Yan
- Biodesign Center for Molecular Design and Biomimetics Arizona State University USA
- School of Molecular Sciences Arizona State University Tempe AZ 85287 USA
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