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Xu X, Jia K, Qi Q, Tian G, Xiang D. Regulation of π-π interactions between single aromatic molecules by bias voltage. Phys Chem Chem Phys 2024; 26:14607-14612. [PMID: 38738917 DOI: 10.1039/d4cp01277a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
π-stacking interaction, as a fundamental type of intermolecular interaction, plays a crucial role in generating new functional molecules, altering the optoelectronic properties of materials, and maintaining protein structural stability. However, regulating intermolecular π-π interactions at the single-molecule level without altering the molecular conformation as well as the chemical properties remains a significant challenge. To this end, via conductance measurement with thousands of single molecular junctions employing a series of aromatic molecules, we demonstrate that the π-π coupling between neighboring aromatic molecules with rigid structures in a circuit can be greatly enhanced by increasing the bias voltage. We further reveal that this universal regulating effect of bias voltage without molecular conformational variation originates from the increases of the molecular dipole upon an applied electric field. These findings not only supply a non-destructive method to regulate the intermolecular interactions offering an approach to modulate the electron transport through a single molecular junction, but also deepen the understanding of the mechanism of π-π interactions.
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Affiliation(s)
- Xiaona Xu
- Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin 300350, China.
| | - Keqiang Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin 300350, China.
| | - Qiang Qi
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, China.
| | - Guangjun Tian
- State Key Laboratory of Metastable Materials Science & Technology and Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao, 066004, China.
| | - Dong Xiang
- Center of Single-Molecule Sciences, Institute of Modern Optics, Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology, Nankai University, Tianjin 300350, China.
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Li Q, Qin C, Chen X, Hu K, Li J, Liu A, Liu S. Enhancing the acid stability of the recombinant GH11 xylanase xynA through N-terminal substitution to facilitate its application in apple juice clarification. Int J Biol Macromol 2024; 268:131857. [PMID: 38670187 DOI: 10.1016/j.ijbiomac.2024.131857] [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: 02/19/2024] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 04/28/2024]
Abstract
The utilization of xylanase in juice clarification is contingent upon its stability within acidic environments. We generated a mutant xynA-1 by substituting the N-terminal segment of the recombinant xylanase xynA to investigate the correlation between the N-terminal region of xylanase and its acid stability. The enzymatic activity of xynA-1 was found to be superior under acidic conditions (pH 5.0). It exhibited enhanced acid stability, surpassing the residual enzyme activity values of xynA at pH 4.0 (53.07 %), pH 4.5 (69.8 %), and pH 5.0 (82.4 %), with values of 60.16 %, 77.74 %, and 87.3 %, respectively. Additionally, the catalytic efficiency of xynA was concurrently improved. Through molecular dynamics simulation, we observed that N-terminal shortening induced a reduction in motility across most regions of the protein structure while enhancing its stability, particularly Lys131-Phe146 and Leu176-Gly206. Furthermore, the application of treated xynA-1 in the process of apple juice clarification led to a significant increase in clarity within a short duration of 20 min at 35 °C while ensuring the quality of the apple juice. This study not only enhances the understanding of the N-terminal region of xylanase but also establishes a theoretical basis for augmenting xylanase resources employed in fruit juice clarification.
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Affiliation(s)
- Qin Li
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China.
| | - Chi Qin
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China
| | - Xingziyi Chen
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China
| | - Kaidi Hu
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China
| | - Jianlong Li
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China
| | - Aiping Liu
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China
| | - Shuliang Liu
- College of Food Science, Sichuan Agricultural University, Ya'an, Sichuan 625014, People's Republic of China.
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Xia Y, Wang W, Wei Y, Guo C, Song S, Cai S, Miao Y. Clustered surface amino acid residues modulate the acid stability of GH10 xylanase in fungi. Appl Microbiol Biotechnol 2024; 108:216. [PMID: 38363378 PMCID: PMC10873454 DOI: 10.1007/s00253-024-13045-1] [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: 12/23/2023] [Revised: 01/15/2024] [Accepted: 01/28/2024] [Indexed: 02/17/2024]
Abstract
Acidic xylanases are widely used in industries such as biofuels, animal feeding, and fruit juice clarification due to their tolerance to acidic environments. However, the factors controlling their acid stability, especially in GH10 xylanases, are only partially understood. In this study, we identified a series of thermostable GH10 xylanases with optimal temperatures ranging from 70 to 90 °C, and among these, five enzymes (Xyn10C, Xyn10RE, Xyn10TC, Xyn10BS, and Xyn10PC) exhibited remarkable stability at pH 2.0. Our statistical analysis highlighted several factors contributing to the acid stability of GH10 xylanases, including electrostatic repulsion, π-π stacking, ionic bonds, hydrogen bonds, and Van der Waals interactions. Furthermore, through mutagenesis studies, we uncovered that acid stability is influenced by a complex interplay of amino acid residues. The key amino acid sites determining the acid stability of GH10 xylanases were thus elucidated, mainly concentrated in two surface regions behind the enzyme active center. Notably, the critical residues associated with acid stability markedly enhanced Xyn10RE's thermostability by more than sixfold, indicating a potential acid-thermal interplay in GH10 xylanases. This study not only reported a series of valuable genes but also provided a range of modification targets for enhancing the acid stability of GH10 xylanases. KEY POINTS: • Five acid stable and thermostable GH10 xylanases were reported. • The key amino acid sites, mainly forming two enriched surface regions behind the enzyme active center, were identified responsible for acid stability of GH10 xylanases. • The finding revealed interactive amino acid sites, offering a pathway for synergistic enhancement of both acid stability and thermostability in GH10 xylanase modifications.
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Affiliation(s)
- Yanwei Xia
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wei Wang
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yaning Wei
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Chuanxu Guo
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Sisi Song
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Siqi Cai
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China
| | - Youzhi Miao
- Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, National Engineering Research Center for Organic-Based Fertilizers, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, 210095, China.
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Zhang Z, Zhao Z, Huang K, Liang Z. Acid-resistant enzymes: the acquisition strategies and applications. Appl Microbiol Biotechnol 2023; 107:6163-6178. [PMID: 37615723 DOI: 10.1007/s00253-023-12702-1] [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: 06/05/2023] [Revised: 07/18/2023] [Accepted: 07/21/2023] [Indexed: 08/25/2023]
Abstract
Enzymes have promising applications in chemicals, food, pharmaceuticals, and other variety products because of their high efficiency, specificity, and environmentally friendly properties. However, due to the complexity of raw materials, pH, temperature, solvents, etc., the application range of enzymes is greatly limited in the industry. Protein engineering and enzyme immobilization are classical strategies to overcome the limitations of industrial applications. Although the pH tendency of enzymes has been extensively researched, the mechanism underlying enzyme acid resistance is unclear, and a less practical strategy for altering the pH propensity of enzymes has been suggested. This review proposes that the optimum pH of enzyme is determined by the pKa values of active center ionizable amino acid residues. Three levels of acquiring acid-resistant enzymes are summarized: mining from extreme environments and enzyme databases, modification with protein engineering and enzyme microenvironment engineering, and de novo synthesis. The industrial applications of acid-resistant enzymes in chemicals, food, and pharmaceuticals are also summarized. KEY POINTS: • The mechanism of enzyme acid resistance is fundamentally determined. • The three aspects of the method for acquiring acid-resistant enzymes are summarized. • Computer-aided strategies and artificial intelligence are used to obtain acid-resistant enzymes.
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Affiliation(s)
- Zhenzhen Zhang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Zitong Zhao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Kunlun Huang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
- The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing, China
- Beijing Laboratory for Food Quality and Safety, China Agricultural University, Beijing, China
| | - Zhihong Liang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China.
- The Supervision, Inspection and Testing Center of Genetically Modified Organisms, Ministry of Agriculture, Beijing, China.
- Beijing Laboratory for Food Quality and Safety, China Agricultural University, Beijing, China.
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Li SF, Cheng F, Wang YJ, Zheng YG. Strategies for tailoring pH performances of glycoside hydrolases. Crit Rev Biotechnol 2023; 43:121-141. [PMID: 34865578 DOI: 10.1080/07388551.2021.2004084] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Glycoside hydrolases (GHs) exhibit high activity and stability under harsh conditions, such as high temperatures and extreme pHs, given their wide use in industrial biotechnology. However, strategies for improving the acidophilic and alkalophilic adaptations of GHs are poorly summarized due to the complexity of the mechanisms of these adaptations. This review not only highlights the adaptation mechanisms of acidophilic and alkalophilic GHs under extreme pH conditions, but also summarizes the recent advances in engineering the pH performances of GHs with a focus on four strategies of protein engineering, enzyme immobilization, chemical modification, and medium engineering (additives). The examples described here summarize the methods used in modulating the pH performances of GHs and indicate that methods integrated in different protein engineering techniques or methods are efficient to generate industrial biocatalysts with the desired pH performance and other adapted enzyme properties.
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Affiliation(s)
- Shu-Fang Li
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Feng Cheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Ya-Jun Wang
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
| | - Yu-Guo Zheng
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, P. R. China.,Engineering Research Center of Bioconversion and Biopurification of the Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang, P. R. China.,The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, Hangzhou, P. R. China
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Enhanced acidic resistance ability and catalytic properties of Bacillus 1,3-1,4-β-glucanases by sequence alignment and surface charge engineering. Int J Biol Macromol 2021; 192:426-434. [PMID: 34627850 DOI: 10.1016/j.ijbiomac.2021.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/13/2021] [Accepted: 10/02/2021] [Indexed: 11/24/2022]
Abstract
High stability at acidic environment is required for 1,3-1,4-β-glucanase to function in biofuel, brewing and animal feed industries. In this study, a mesophilic β-glucanase from Bacillus terquilensis CGX 5-1 was rationally engineered through sequence alignment and surface charge engineering to improve its acidic resistance ability. Nineteen singly-site variants were constructed and Q1E, I133L and V134A variants showed better acidic stability without the compromise of catalytic property and thermostability. Furthermore, four multi-site variants were constructed and one double-site variant Q1E/I133L with better stability at acidic environment and higher catalytic property was obtained. The fluorescence spectroscopy and structural analysis showed that more surface negative charge, decreased exposure degree of residue No.1, shifted side chain direction of residue No.133 and the lower total and folding free energy might be the reason for the improvement of acidic stability of Q1E/I133L variant. The obtained Q1E/I133L variant has potential applications in industries.
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Zhang Y, Tang J, Zhang W, Ai J, Liu Y, Wang Q, Wang D. Preparation of ultrahigh-surface-area sludge biopolymers-based carbon using alkali treatment for organic matters recovery coupled to catalytic pyrolysis. J Environ Sci (China) 2021; 106:83-96. [PMID: 34210442 DOI: 10.1016/j.jes.2021.01.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 06/13/2023]
Abstract
In this work, we employed waste activated sludge (WAS) as carbon source to prepare ultrahigh specific surface area (SSA) biopolymers-based carbons (BBCs) through alkali (KOH) treatment coupled to pyrolysis strategy. Before the pyrolysis process, the involvement of KOH made a great recovery of soluble biopolymers from WAS, resulting in highly-efficient catalytic pyrolysis. The Brunner-Emmett-Teller and pore volume of BBCs prepared at 800°C (BBC800) reached the maximum at 2633.89 m2·g-1 and 2.919 m3·g-1, respectively. X-ray photoelectron spectroscopy suggested that aromatic carbon in the form of C=C was the dominant fraction of C element in BBCs. The N element in BBCs were composed of pyrrolic nitrogen and pyridinic nitrogen at 700°C, while a new graphitic nitrogen appeared over 800°C. As a refractory pollutant of wastewater treatment plants, tetracycline (TC) was selected to evaluate adsorption performance of BBCs. The adsorption behavior of BBCs towards TC was conformed to the pseudo-second-order kinetic and the Langmuir models, signifying that chemisorption of monolayers was dominant in TC adsorption. The adsorption capacity of BBC800 reached the maximum at 877.19 mg·g-1 for 90 min at 298 K. Thermodynamic analysis indicated that the adsorption process was endothermic and spontaneous. Hydrogen bonding and π-π stacking interaction were mainly responsible for TC adsorption, and interfacial diffusion was the main rate-control step in adsorption process. The presence of soluble microbial products (SMPs) enhanced TC removal. This work provided a novel strategy to prepare bio-carbon with ultrahigh SSA using WAS for highly-efficient removal of organic pollutants.
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Affiliation(s)
- Yu Zhang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Jiayi Tang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Weijun Zhang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; Hubei Provincial Engineering Research Center of Systematic Water Pollution Control, Wuhan 430074, China.
| | - Jing Ai
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Yanyang Liu
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430074, China
| | - Qiandi Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China
| | - Dongsheng Wang
- School of Environmental Studies, China University of Geosciences, Wuhan 430074, China; State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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Assaba IM, Rahali S, Belhocine Y, Allal H. Inclusion complexation of chloroquine with α and β-cyclodextrin: Theoretical insights from the new B97-3c composite method. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129696] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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9
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Tang Y, Zhou Y, Zhou D, Chen Y, Xiao Z, Shi J, Liu J, Hong W. Electric Field-Induced Assembly in Single-Stacking Terphenyl Junctions. J Am Chem Soc 2020; 142:19101-19109. [DOI: 10.1021/jacs.0c07348] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yongxiang Tang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yu Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Dahai Zhou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Yaorong Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Zongyuan Xiao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Junyang Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, NEL, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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