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Sengupta S, Chanda P, Manna B, Ghosh A, Datta S. Rational Engineering of a β-Glucosidase (H0HC94) from Glycosyl Hydrolase Family I (GH1) to Improve Catalytic Performance on Cellobiose. J Phys Chem B 2024. [PMID: 39221646 DOI: 10.1021/acs.jpcb.4c03464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
The conversion of lignocellulosic feedstocks by cellulases to glucose is a critical step in biofuel production. β-Glucosidases catalyze the final step in cellulose breakdown, producing glucose, and are often the rate-limiting step in biomass hydrolysis. The specific activity of most natural and engineered β-glucosidase is higher on the artificial substrate p-nitrophenyl β-d-glucopyranoside (pNPGlc) than on the natural substrate, cellobiose. We report an engineered β-glucosidase (Q319A H0HC94) with a 1.8-fold higher specific activity (366.3 ± 36 μmol/min/mg), a 1.5-fold increase in kcat (340.8 ± 27 s-1), and a 3-fold increase in catalytic efficiency (236.65 mM-1 s-1) over H0HC94 (WT) on cellobiose. Molecular dynamic simulations and protein structure network analysis indicate that the Q319A H0HC94 active site pocket is significantly remodeled compared to the WT, leading to changes in enzyme conformation, better accessibility of cellobiose inside the active site pocket, and higher enzymatic activity. This study shows the impact of rational engineering of a nonconserved residue to increase β-glucosidase substrate accessibility and catalytic efficiency by reducing crowding interaction between cellobiose and active site pocket residues near the gatekeeper region and increasing pocket volume and surface area. Thus, rational engineering of previously characterized enzymes could be an excellent strategy to improve cellulose hydrolysis.
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Affiliation(s)
- Sauratej Sengupta
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Pinaki Chanda
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Bharat Manna
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Amit Ghosh
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
| | - Supratim Datta
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
- Center for the Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
- Center for the Climate and Environmental Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
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Das M, Ghosh A. Molecular insights into mutation-induced conformational changes in Acetyl CoA Carboxylase for improved activity. Int J Biol Macromol 2024; 256:128417. [PMID: 38016612 DOI: 10.1016/j.ijbiomac.2023.128417] [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: 07/18/2023] [Revised: 11/16/2023] [Accepted: 11/23/2023] [Indexed: 11/30/2023]
Abstract
Acetyl-CoA carboxylase (ACCase) is crucial for fatty acid biosynthesis and has potential applications in lipid accumulation and advanced biofuel production. Mutations like S659A and S1157A in Saccharomyces cerevisiae ACCase remove the Snf1-regulation sites, resulting in increased enzyme activity with positive effects on the fatty acid pathway. However, the molecular-level understanding of these mutations on ACCase activity remains unexplored. Here, molecular dynamics simulation was conducted to investigate the mutations-induced conformational changes in S. cerevisiae ACCase. The wild-type ACCase was observed to have significant deviation in structure compared to mutant. Additionally, fluctuation of residues associated with biotin binding and Snf1-recognition were reduced in mutant compared to wild-type. Furthermore, the wild-type demonstrated opening motions of the domains, whereas the mutant showed closing movement. The mutation-induced conformational changes were analysed using network parameters, i.e., cliques/communities. The mutant showed an increase in sizes of several communities in AC3-AC4-AC5 domains leading to rigidification. Also, a new community was added in AC1-BT in the mutant, which suggested a substantial shift in the protein conformation. Thus, this study provides a theoretical understanding of the increased activity of ACCase due to two mutations, which can pave the path for enzyme engineering towards improved fatty acid-based fuel and chemical production.
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Affiliation(s)
- Manali Das
- School of Bioscience, Indian Institute of Technology Kharagpur, West Bengal-721302, India
| | - Amit Ghosh
- P.K. Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, West Bengal 721302, India; School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
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Manna B, Chanda P, Datta S, Ghosh A. Elucidating the Ionic Liquid-Induced Mixed Inhibition of GH1 β-Glucosidase H0HC94. J Phys Chem B 2023; 127:8406-8416. [PMID: 37751511 DOI: 10.1021/acs.jpcb.3c02125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Deciphering the ionic liquid (IL) tolerance of glycoside hydrolases (GHs) to improve their hydrolysis efficiency for fermentable sugar synthesis in the "one-pot" process has long been a hurdle for researchers. In this work, we employed experimental and theoretical approaches to investigate the 1-ethyl-3-methylimidazolium acetate ([C2C1im][MeCO2])-induced inhibition of GH1 β-glucosidase (H0HC94) from Agrobacterium tumefaciens 5A. At 10-15% [C2C1im][MeCO2] concentration, H0HC94 experiences competitive inhibition (R2 = 0.97, alpha = 2.8). As the IL content increased to 20-25%, the inhibition pattern shifted to mixed-type inhibition (R2 = 0.98, alpha = 3.4). These findings were further confirmed through characteristic inhibition plots using Lineweaver-Burk plots. Atomistic molecular dynamics simulations conducted with 0% [C2C1im][MeCO2], 10% [C2C1im][MeCO2], and 25% [C2C1im][MeCO2] revealed the accumulation of [C2C1im]+ at the negatively charged active site of H0HC94 in 10% [C2C1im][MeCO2], supporting the occurrence of competitive inhibition at lower IL concentrations. At higher IL concentrations, the cations and anions bound to the secondary binding sites (SBSs) of H0HC94, leading to a tertiary conformational change, as captured by the principal component analysis based on the free-energy landscape and protein structure networks. The altered conformation of H0HC94 affected the interaction with [C2C1im][MeCO2], which could possibly shift the inhibition from competitive to more mixed-type (competitive + noncompetitive) inhibition, as observed in the experiments. For the first time, we report a combined experimental and theoretical insight behind the mixed inhibition of a GH1 β-glucosidase. Our findings indicated the role of SBS in IL-induced inhibition, which could aid in developing more IL-tolerant β-glucosidases for biorefinery applications.
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Affiliation(s)
- Bharat Manna
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal741246, India
| | - Pinaki Chanda
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal741246, India
| | - Supratim Datta
- Protein Engineering Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal741246, India
- Center for the Advanced Functional Materials, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
- Center for the Climate and Environmental Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal 741246, India
| | - Amit Ghosh
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
- P.K. Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India
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Zhao J, Wilkins MR, Wang D. A review on strategies to reduce ionic liquid pretreatment costs for biofuel production. BIORESOURCE TECHNOLOGY 2022; 364:128045. [PMID: 36182017 DOI: 10.1016/j.biortech.2022.128045] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 09/23/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Worldwide demand for renewable energy has promoted the considerable exploration of biofuel production from lignocellulosic biomass. Ionic liquid pretreatment is of great interest to render biomass amenable for biofuel production, however, its unaffordable cost stimulates significant attention to the feasibility of commercialization. This review aims to compile the latest advances with respect to reducing production costs for ionic liquids-based biorefineries. Protic ionic liquids offer relatively low synthesis costs, but excessive antisolvent washing of the pretreated biomass is often inevitable. Recovering ionic liquids requires several separation and purification steps, and the reuse of ionic liquids could significantly lose functionality due to the degradation. It is promising to screen ionic liquids-tolerant enzymes and strains for one-pot saccharification and fermentation without solid-liquid separation, however, there is still a need for subsequent recovery of ionic liquids. Additionally, technoeconomic analysis and life cycle assessment are highly recommended to evaluate the economic and environmental impacts.
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Affiliation(s)
- Jikai Zhao
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Mark R Wilkins
- Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS 66506, USA
| | - Donghai Wang
- Department of Biological and Agricultural Engineering, Kansas State University, Manhattan, KS 66506, USA.
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Enhanced activity of hyperthermostable Pyrococcus horikoshii endoglucanase in superbase ionic liquids. Biotechnol Lett 2022; 44:961-974. [PMID: 35763164 PMCID: PMC9356960 DOI: 10.1007/s10529-022-03268-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/31/2022] [Indexed: 11/08/2022]
Abstract
Objectives Ionic liquids (ILs) that dissolve biomass are harmful to the enzymes that degrade lignocellulose. Enzyme hyperthermostability promotes a tolerance to ILs. Therefore, the limits of hyperthemophilic Pyrococcus horikoschii endoglucanase (PhEG) to tolerate 11 superbase ILs were explored. Results PhEG was found to be most tolerant to 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) in soluble 1% carboxymethylcellulose (CMC) and insoluble 1% Avicel substrates. At 35% concentration, this IL caused an increase in enzyme activity (up to 1.5-fold) with CMC. Several ILs were more enzyme inhibiting with insoluble Avicel than with soluble CMC. Km increased greatly in the presence ILs, indicating significant competitive inhibition. Increased hydrophobicity of the IL cation or anion was associated with the strongest enzyme inhibition and activation. Surprisingly, PhEG activity was increased 2.0–2.5-fold by several ILs in 4% substrate. Cations exerted the main role in competitive inhibition of the enzyme as revealed by their greater binding energy to the active site. Conclusions These results reveal new ways to design a beneficial combination of ILs and enzymes for the hydrolysis of lignocellulose, and the strong potential of PhEG in industrial, high substrate concentrations in aqueous IL solutions. Supplementary Information The online version contains supplementary material available at 10.1007/s10529-022-03268-5.
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Li Z, Han Q, Wang K, Song S, Xue Y, Ji X, Zhai J, Huang Y, Zhang S. Ionic liquids as a tunable solvent and modifier for biocatalysis. CATALYSIS REVIEWS 2022. [DOI: 10.1080/01614940.2022.2074359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Zhuang Li
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Qi Han
- School of Science, STEM College, RMIT University, Melbourne, Victoria, Australia
| | - Kun Wang
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Shaoyu Song
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Yaju Xue
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Xiuling Ji
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
| | - Jiali Zhai
- School of Science, STEM College, RMIT University, Melbourne, Victoria, Australia
| | - Yuhong Huang
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
- Innovation Academy for Green Manufacture, CAS, Beijing, China
- Dalian National Laboratory for Clean Energy, CAS, Dalian, Liaoning, China
| | - Suojiang Zhang
- Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China
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Radhakrishnan R, Manna B, Ghosh A. Solvent induced conformational changes for the altered activity of laccase: A molecular dynamics study. JOURNAL OF HAZARDOUS MATERIALS 2022; 423:127123. [PMID: 34530268 DOI: 10.1016/j.jhazmat.2021.127123] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/23/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
The growing demands of solvent-based industries like paint, pharmaceutical, petrochemical, paper and pulp, etc., have directly increased the release of effluents that are rich in hazardous aromatic compounds in the environment. A sustainable biotechnological approach utilizing laccases as biocatalyst enable in biodegradation of these aromatic toxin-rich effluents. However, this enzymatic process is ineffective as laccases lose their stability and catalytic activity at high organic solvent concentrations. In this study, molecular dynamic simulations of a novel solvent tolerant laccase, DLac from Cerrena sp. RSD1 was performed to explore the molecular-level understanding of DLac in 30%(v/v) acetone and acetonitrile. Solvent-induced conformational changes were analyzed via protein structure network, which was illustrated with respect to cliques and communities. In the presence of acetonitrile, the cliques around the active site and substrate-binding site were disjoined, thus the communities lost their network integrity. Whereas with acetone, the community near the substrate-binding site gained new residues and formed a rigidified network that corresponded to enhanced DLac's activity. Moreover, prominent solvent binding sites were speculated, which can be probable mutation targets to further improve solvent tolerance and catalytic activity. The molecular basis behind solvent induced catalytic activity will further aid in engineering laccase for its industrial application.
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Affiliation(s)
- Rokesh Radhakrishnan
- P.K. Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - Bharat Manna
- School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, West Bengal 721302, India
| | - Amit Ghosh
- P.K. Sinha Centre for Bioenergy and Renewables, Indian Institute of Technology Kharagpur, West Bengal 721302, India; School of Energy Science and Engineering, Indian Institute of Technology Kharagpur, West Bengal 721302, India.
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