1
|
Chen Q, Wu J, Wu Y, Wang Z, Zeng M, He Z, Chen J, Mu W. Rational Design of Loop Dynamics for a Barrel-Shaped Enzyme by Introducing Disulfide Bonds. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:13856-13868. [PMID: 38848490 DOI: 10.1021/acs.jafc.4c03493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2024]
Abstract
Loop dynamics redesign is an important strategy to manipulate protein function. Cellobiose 2-epimerase (CE) and other members of its superfamily are widely used for diverse industrial applications. The structural feature of the loops connecting barrel helices contributes greatly to the differences in their functional characteristics. Inspired by the in-silico mutation with molecular dynamics (MD) simulation analysis, we propose a strategy for identifying disulfide bond mutation candidates based on the prediction of protein flexibility and residue-residue interaction. The most beneficial mutant with the newly introduced disulfide bond would simultaneously improve both its thermostability and its reaction propensity to the targeting isomerization product. The ratio of the isomerization/epimerization catalytic rate was improved from 4:103 to 9:22. MD simulation and binding free energy calculations were applied to provide insights into molecular recognition upon mutations. The comparative analysis of enzyme/substrate binding modes indicates that the altered catalytic reaction pathway is due to less efficient binding of the native product. The key residue responsible for the observed phenotype was identified by energy decomposition and was further confirmed by the mutation experiment. The rational design of the key loop region might be a promising strategy to alter the catalytic behavior of all (α/α)6-barrel-like proteins.
Collapse
Affiliation(s)
- Qiuming Chen
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Junhao Wu
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Yanchang Wu
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Zhaojun Wang
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Maomao Zeng
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Zhiyong He
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Jie Chen
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Resources, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi Jiangsu 214122, P. R. China
| |
Collapse
|
2
|
Feng Y, Lyu X, Cong Y, Miao T, Fang B, Zhang C, Shen Q, Matthews M, Fisher AJ, Zhang JZH, Zhang L, Yang R. A precise swaying map for how promiscuous cellobiose-2-epimerase operate bi-reaction. Int J Biol Macromol 2023; 253:127093. [PMID: 37758108 DOI: 10.1016/j.ijbiomac.2023.127093] [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: 08/09/2023] [Revised: 09/24/2023] [Accepted: 09/24/2023] [Indexed: 10/02/2023]
Abstract
Promiscuous enzymes play a crucial role in organism survival and new reaction mining. However, comprehensive mapping of the catalytic and regulatory mechanisms hasn't been well studied due to the characteristic complexity. The cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) with complex epimerization and isomerization was chosen to comprehensively investigate the promiscuous mechanisms. Here, the catalytic frame of ring-opening, cis-enediol mediated catalysis and ring-closing was firstly determined. To map the full view of promiscuous CE, the structure of CsCE complex with the isomerized product glucopyranosyl-β1,4-fructose was determined. Combined with computational calculation, the promiscuity was proved a precise cooperation of the double subsites, loop rearrangement, and intermediate swaying. The flexible loop was like a gear, whose structural reshaping regulates the sway of the intermediates between the two subsites of H377-H188 and H377-H247, and thus regulates the catalytic directions. The different protonated states of cis-enediol intermediate catalyzed by H188 were the key point for the catalysis. The promiscuous enzyme tends to utilize all elements at hand to carry out the promiscuous functions.
Collapse
Affiliation(s)
- Yinghui Feng
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China; State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Yalong Cong
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Tingwei Miao
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Bohuan Fang
- Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Chuanxi Zhang
- Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qiang Shen
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China
| | - Melissa Matthews
- Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan; Department of Chemistry, University of California Davis, Davis, CA 95616, United States; Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, United States
| | - Andrew J Fisher
- Department of Chemistry, University of California Davis, Davis, CA 95616, United States; Department of Molecular and Cellular Biology, University of California Davis, Davis, CA 95616, United States
| | - John Z H Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China; Department of Chemistry, New York University, New York, NY 10003, United States
| | - Lujia Zhang
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China; NYU-ECNU Center for Computational Chemistry at NYU Shanghai, Shanghai 200062, China.
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, 214122 Wuxi, China; Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu 214122, China.
| |
Collapse
|
3
|
Jia DX, Yu H, Wang F, Jin LQ, Liu ZQ, Zheng YG. Computer-aided design of novel cellobiose 2-epimerase for efficient synthesis of lactulose using lactose. Bioprocess Biosyst Eng 2023:10.1007/s00449-023-02896-z. [PMID: 37450268 DOI: 10.1007/s00449-023-02896-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023]
Abstract
Cellobiose 2-epimerase (CE) is ideally suited to synthesize lactulose from lactose, but the poor thermostability and catalytic efficiency restrict enzymatic application. Herein, a non-characterized CE originating from Caldicellulosiruptor morganii (CmCE) was discovered in the NCBI database. Then, a smart mutation library was constructed based on FoldX ΔΔG calculation and modeling structure analysis, from which a positive mutant D226G located within the α8/α9 loop exhibited longer half-lives at 65-75 °C as well as lower Km and higher kcat/Km values compared with CmCE. Molecular modeling demonstrated that the improvement of D226G was largely attributed to the rigidification of the flexible loop, the compactness of the catalysis pocket and the increment of substrate-binding capability. Finally, the yield of synthesizing lactulose catalyzed by D226G reached 45.5%, higher than the 35.9% achieved with CmCE. The disclosed effect of the flexible loop on enzymatic stability and catalysis provides insight to redesign efficient CEs to biosynthesize lactulose.
Collapse
Affiliation(s)
- Dong-Xu Jia
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Hai Yu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Fan Wang
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Li-Qun Jin
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| | - Zhi-Qiang Liu
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China.
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China.
| | - Yu-Guo Zheng
- The National and Local Joint Engineering Research Center for Biomanufacturing of Chiral Chemicals, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, People's Republic of China
| |
Collapse
|
4
|
Kim SY, Cho HY, Yoon SI. Unique dimeric structure of the DUF2891 family protein CJ0554 from Campylobacter jejuni. Biochem Biophys Res Commun 2023; 655:11-17. [PMID: 36913761 DOI: 10.1016/j.bbrc.2023.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/05/2023] [Indexed: 03/08/2023]
Abstract
Campylobacter jejuni is a pathogenic bacterium that causes enteritis and Guillain-Barre syndrome in humans. To identify a protein target for the development of a new therapeutic against C. jejuni infection, each gene product of C. jejuni must be functionally characterized. The cj0554 gene of C. jejuni encodes a DUF2891 family protein with unknown functions. To provide functional insights into CJ0554, we determined and analyzed the crystal structure of the CJ0554 protein. CJ0554 adopts an (α/α)6-barrel structure, which consists of an inner α6 ring and an outer α6 ring. CJ0554 assembles into a dimer in a unique top-to-top orientation that is not observed in its structural homologs, N-acetylglucosamine 2-epimerase superfamily members. Dimer formation was verified by analyzing CJ0554 and its ortholog protein through gel-filtration chromatography. The top of the CJ0554 monomer barrel harbors a cavity, which is connected to that of the second subunit in the dimer structure, generating a larger intersubunit cavity. This elongated cavity accommodates extra nonproteinaceous electron density, presumably as a pseudosubstrate, and is lined with generally catalytically active histidine residues that are invariant in CJ0554 orthologs. Therefore, we propose that the cavity functions as the active site of CJ0554.
Collapse
Affiliation(s)
- Seung Yeon Kim
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Hye Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
| |
Collapse
|
5
|
Wang L, Gu J, Zhao W, Wang M, Ng KR, Lyu X, Yang R. Reshaping the Binding Pocket of Cellobiose 2-Epimerase for Improved Substrate Affinity and Isomerization Activity for Enabling Green Synthesis of Lactulose. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:15879-15893. [PMID: 36475670 DOI: 10.1021/acs.jafc.2c06980] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Enzymatic isomerization of lactose into lactulose via cellobiose 2-epimerase (CE) could provide an eco-friendly route for the industrial production of lactulose, a valuable food prebiotic. However, poor substrate affinity for lactose and preference for epimerization over isomerization hinder this application. Previous studies on CE improvement have focused on random mutagenesis or active site rational design; little is known about the relationship between substrate binding and enzyme efficacy, which was hence the subject of this study. First, residues 372W and 308W were identified as key for disaccharide recognition in CEs based on crystal structure alignment of the N-acetyl-glucosamine 2-epimerase superfamily and site-directed mutation. This binding domain was then reshaped through site saturation mutagenesis, resulting in seven mutants with enhanced isomerization activity. The optimal mutant CsCE/Q371E had significantly enhanced substrate affinity (Km, 269.65 mM vs Km, 417.5 mM), reduced epimerization activity, and 3.3-fold increased isomerization activity over the original CsCE. Molecular dynamics simulation further revealed that substituting Gln-371 with Glu strengthened the hydrogen-bonding network and altered the active site-substrate interactions, increasing the substrate stability and shifting the catalytic direction. This study uncovered new information about the substrate binding region and its mechanisms and impact on CE catalytic performance, paving the way for potential commercial applications.
Collapse
Affiliation(s)
- Lu Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jiali Gu
- College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Wei Zhao
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Mingming Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Kuan Rei Ng
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| |
Collapse
|
6
|
Wang M, Wang L, Lyu X, Hua X, Goddard JM, Yang R. Lactulose production from lactose isomerization by chemo-catalysts and enzymes: Current status and future perspectives. Biotechnol Adv 2022; 60:108021. [PMID: 35901861 DOI: 10.1016/j.biotechadv.2022.108021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 07/02/2022] [Accepted: 07/17/2022] [Indexed: 11/29/2022]
Abstract
Lactulose, a semisynthetic nondigestive disaccharide with versatile applications in the food and pharmaceutical industries, has received increasing interest due to its significant health-promoting effects. Currently, industrial lactulose production is exclusively carried out by chemical isomerization of lactose via the Lobry de Bruyn-Alberda van Ekenstein (LA) rearrangement, and much work has been directed toward improving the conversion efficiency in terms of lactulose yield and purity by using new chemo-catalysts and integrated catalytic-purification systems. Lactulose can also be produced by an enzymatic route offering a potentially greener alternative to chemo-catalysis with fewer side products. Compared to the controlled trans-galactosylation by β-galactosidase, directed isomerization of lactose with high isomerization efficiency catalyzed by the most efficient lactulose-producing enzyme, cellobiose 2-epimerase (CE), has gained much attention in recent decades. To further facilitate the industrial translation of CE-based lactulose biotransformation, numerous studies have been reported on improving biocatalytic performance through enzyme mediated molecular modification. This review summarizes recent developments in the chemical and enzymatic production of lactulose. Related catalytic mechanisms are also highlighted and described in detail. Emerging techniques that aimed at advancing lactulose production, such as the boronate affinity-based technique and molecular biological techniques, are reviewed. Finally, perspectives on challenges and opportunities in lactulose production and purification are also discussed.
Collapse
Affiliation(s)
- Mingming Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China; College of Food Science and Engineering, Ocean University of China, Qingdao, Shandong Province 266003, China; Department of Food Science, Cornell University, Ithaca, NY 14853, USA
| | - Lu Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Xiao Hua
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China
| | - Julie M Goddard
- Department of Food Science, Cornell University, Ithaca, NY 14853, USA.
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Wuxi, China.
| |
Collapse
|
7
|
Wang L, Gu J, Feng Y, Wang M, Tong Y, Liu Y, Lyu X, Yang R. Enhancement of the Isomerization Activity and Thermostability of Cellobiose 2-Epimerase from Caldicellulosiruptor saccharolyticus by Exchange of a Flexible Loop. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:1907-1915. [PMID: 33541071 DOI: 10.1021/acs.jafc.0c07073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Cellobiose 2-epimerase (CE) offers a promising enzymatic approach to produce lactulose. However, its application is limited by the unsatisfactory isomerization activity and thermostability. Our study attempted to optimize the catalytic performances of CEs by flexible loop exchange, for which four mutants were constructed using CsCE (CE from Caldicellulosiruptor saccharolyticus) as a template. As a result, all mutants maintained the same catalytic directions as the templates. Mutant RmC displayed a 2.2- and 1.34-fold increase in the isomerization activity and catalytic efficiency, respectively. According to the results of molecular dynamics (MD) simulations, it was revealed that the loop exchange in RmC enlarged the entrance of the active site for substrate binding and benefited proton transfer involved in the isomerization process. Besides, the t1/2 of mutant StC at 70 °C was increased from 29.07 to 38.29 h, owing to the abundance of rigid residues (proline) within the flexible loop of StC. Our work demonstrated that the isomerization activity and thermostability of CEs were closely related to the flexible loop surrounding the active site, which provides a new perspective to engineer CEs for higher lactulose production.
Collapse
Affiliation(s)
- Lu Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jiali Gu
- College of Life Sciences, Huzhou University, Huzhou 313000, China
| | - Yinghui Feng
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Mingming Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yanjun Tong
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Yingjie Liu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiaomei Lyu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Ruijin Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| |
Collapse
|