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Chen Q, Wang J, Zhang S, Chen X, Hao J, Wu Q, Zhu D. Discovery and directed evolution of C-C bond formation enzymes for the biosynthesis of β-hydroxy-α-amino acids and derivatives. Crit Rev Biotechnol 2024:1-20. [PMID: 38566472 DOI: 10.1080/07388551.2024.2332295] [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: 11/24/2023] [Accepted: 02/16/2024] [Indexed: 04/04/2024]
Abstract
β-Hydroxy-α-amino acids (β-HAAs) have extensive applications in the pharmaceutical, chemical synthesis, and food industries. The development of synthetic methodologies aimed at producing optically pure β-HAAs has been driven by practical applications. Among the various synthetic methods, biocatalytic asymmetric synthesis is considered a sustainable approach due to its capacity to generate two stereogenic centers from simple prochiral precursors in a single step. Therefore, extensive efforts have been made in recent years to search for effective enzymes which enable such biotransformation. This review provides an overview on the discovery and engineering of C-C bond formation enzymes for the biocatalytic synthesis of β-HAAs. We highlight examples where the use of threonine aldolases, threonine transaldolases, serine hydroxymethyltransferases, α-methylserine aldolases, α-methylserine hydroxymethyltransferases, and engineered alanine racemases facilitated the synthesis of β-HAAs. Additionally, we discuss the potential future advancements and persistent obstacles in the enzymatic synthesis of β-HAAs.
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Affiliation(s)
- Qijia Chen
- College of Food Science and Biology, University of Science and Technology, Shijiazhuang, China
| | - Jingmin Wang
- College of Food Science and Biology, University of Science and Technology, Shijiazhuang, China
| | - Sisi Zhang
- College of Food Science and Biology, University of Science and Technology, Shijiazhuang, China
| | - Xi Chen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Jianxiong Hao
- College of Food Science and Biology, University of Science and Technology, Shijiazhuang, China
| | - Qiaqing Wu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
| | - Dunming Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China
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Xi Z, Xu Y, Liu Z, Zhang X, Zhu Q, Li L, Zhang R. Enhanced synthesis of chloramphenicol intermediate L-threo-p-nitrophenylserine using engineered L-threonine transaldolase and by-product elimination. Int J Biol Macromol 2024; 263:130310. [PMID: 38382774 DOI: 10.1016/j.ijbiomac.2024.130310] [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: 11/23/2023] [Revised: 02/16/2024] [Accepted: 02/18/2024] [Indexed: 02/23/2024]
Abstract
L-threo-p-nitrophenylserine (component 2) is an important intermediate during synthesis of chloramphenicol. However, its biosynthesis is limited by enzyme activity and stereoselectivity. In this study, we achieved a breakthrough in the high-efficiency production of 2 by employing engineered Chitiniphilus shinanonensis L-threonine transaldolase (ChLTTA) in conjunction with a by-product elimination system within a one-pot reaction. Notably, a novel visual stepwise high-throughput screening method was developed for the directed evolution of ChLTTA, leveraging its characteristic color. The engineered mutant F70D/F59A (Mu6 variant) emerged as a star performer, exhibiting a remarkable 2.6-fold increase in catalytic efficiency over the wild-type ChLTTA, coupled with an outstanding 91.5 % diastereoisomer excess (de). Molecular dynamics (MD) simulations unraveled the mechanism responsible for the enhanced catalytic performance observed in the Mu6 variant. Meanwhile, the Mu6 variant was coupled with Saccharomyces cerevisiae ethanol dehydrogenase (ScADH) and Candida boidinii formate dehydrogenase (CbFDH) to create a high-efficiency cascade system (E.coli/pRSF-Mu6-ScADH-CbFDH). Under optimized conditions, this cascade system demonstrated unparalleled performance, yielding 201.5 mM of 2 with an impressive conversion of 95.9 % and a de value of 94.5 %. This achievement represents the highest reported yield to date. This study offers a novel insight into the sustainable and efficient production of chloramphenicol intermediate.
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Affiliation(s)
- Zhiwen Xi
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Zhiyong Liu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Xinyi Zhang
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Qiang Zhu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Lihong Li
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China
| | - Rongzhen Zhang
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi, 214122, PR China.
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Xi Z, Li L, Liu Z, Wu X, Xu Y, Zhang R. Rational Design of l-Threonine Transaldolase-Mediated System for Enhanced Florfenicol Intermediate Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:461-474. [PMID: 38153324 DOI: 10.1021/acs.jafc.3c05267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2023]
Abstract
l-threo-p-methylsulfonylphenylserine (compound 1b) is the main intermediate of florfenicol, and its efficient synthesis has been the subject of current research. Herein, Burkholderia diffusa l-threonine transaldolase (BuLTTA) was rationally designed based on the sequence-structure-function relationship. A mutant M4 (Asn35Ser/Thr352Asn) could produce 35.5 mM 1b with 88.8% conversion and 93.8% diastereoselectivity, 314 and 129% of the values observed for wild-type BuLTTA. Molecular dynamics simulations indicated that the shortened distance between key active site residues and the transition state (PLP-1b) and the improved hydrogen bond force enhanced the catalytic performance of the M4 variant. Then, the mutant M4 was combined with K. kurtzmanii alcohol dehydrogenase (KkADH) to eliminate the BuLTTA-inhibiting byproduct acetaldehyde, and a cosubstrate was added to regenerate the ADH cofactor NADH. Under optimized conditions, the yield of 1b reached 115.2 mM with a conversion of 96% and a diastereoselectivity of 95.5%. This work provides a new strategy for the efficient and sustainable production of 1b.
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Affiliation(s)
- Zhiwen Xi
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, P. R. China
| | - Lihong Li
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, P. R. China
| | - Zhiyong Liu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, P. R. China
| | - Xiaolong Wu
- Department of Infection Control, Affiliated Hospital of Jiangnan University, 214122 Wuxi, P. R. China
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, P. R. China
| | - Rongzhen Zhang
- Lab of Brewing Microbiology and Applied Enzymology, School of Biotechnology and Key Laboratory of Industrial Biotechnology of Ministry of Education, Jiangnan University, Wuxi 214122, P. R. China
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Zmich A, Perkins LJ, Bingman C, Acheson JF, Buller AR. Multiplexed Assessment of Promiscuous Non-Canonical Amino Acid Synthase Activity in a Pyridoxal Phosphate-Dependent Protein Family. ACS Catal 2023; 13:11644-11655. [PMID: 37720819 PMCID: PMC10501158 DOI: 10.1021/acscatal.3c02498] [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] [Indexed: 09/19/2023]
Abstract
Pyridoxal phosphate (PLP)-dependent enzymes afford access to a variety of non-canonical amino acids (ncAAs), which are premier buildings blocks for the construction of complex bioactive molecules. The vinylglycine ketimine (VGK) subfamily of PLP-dependent enzymes plays a critical role in sulfur metabolism and is home to a growing set of secondary metabolic enzymes that synthesize γ-substituted ncAAs. Identification of VGK enzymes for biocatalysis faces a distinct challenge because the subfamily contains both desirable synthases as well as lyases that break down ncAAs. Some enzymes have both activities, which may contribute to pervasive mis-annotation. To navigate this complex functional landscape, we used a substrate multiplexed screening approach to rapidly measure the substrate promiscuity of 40 homologs in the VGK subfamily. We found that enzymes involved in transsulfuration are less likely to have promiscuous activities and often possess undesirable lyase activity. Enzymes from direct sulfuration and secondary metabolism generally had a high degree of substrate promiscuity. From this cohort, we identified an exemplary γ-synthase from Caldicellulosiruptor hydrothermalis (CahyGS). This enzyme is thermostable and has high expression (~400 mg protein per L culture), enabling preparative scale synthesis of thioether containing ncAAs. When assayed with l-allylglycine, CahyGS catalyzes a stereoselective γ-addition reaction to afford access to a unique set of γ-methyl branched ncAAs. We determined high-resolution crystal structures of this enzyme that define an open-close transition associated with ligand binding and set the stage for future engineering within this enzyme subfamily.
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Affiliation(s)
- Anna Zmich
- Department of Biochemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Lydia J. Perkins
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Craig Bingman
- Department of Biochemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Justin F Acheson
- Department of Biochemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Andrew R. Buller
- Department of Biochemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Meza A, Campbell ME, Zmich A, Thein SA, Grieger AM, McGill MJ, Willoughby PH, Buller AR. Efficient chemoenzymatic synthesis of α-aryl aldehydes as intermediates in C-C bond forming biocatalytic cascades. ACS Catal 2022; 12:10700-10710. [PMID: 36420479 PMCID: PMC9681013 DOI: 10.1021/acscatal.2c02369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multi-enzyme biocatalytic cascades are emerging as practical routes for the synthesis of complex bioactive molecules. However, the relative sparsity of water-stable carbon electrophiles limits the synthetic complexity of molecules made from such cascades. Here, we develop a chemoenzymatic platform that leverages styrene oxide isomerase (SOI) to covert readily accessible aryl epoxides into α-aryl aldehydes through a Meinwald rearrangement. These unstable aldehyde intermediates are then intercepted with a C-C bond forming enzyme, ObiH, that catalyzes a transaldolase reaction with l-threonine to yield synthetically challenging β-hydroxy-α-amino acids. Co-expression of both enzymes in E. coli yields a whole cell biocatalyst capable of synthesizing a variety of stereopure non-standard amino acids (nsAA) and can be produced on gram-scale. We used isotopically labelled substrates to probe the mechanism of SOI, which we show catalyzes a concerted isomerization featuring a stereospecific 1,2-hydride shift. The viability of in situ generated α-aryl aldehydes was further established by intercepting them with a recently engineered decarboxylative aldolase to yield γ-hydroxy nsAAs. Together, these data establish a versatile method of producing α-aryl aldehydes in simple, whole cell conditions and show that these intermediates are useful synthons in C‒C bond forming cascades.
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Affiliation(s)
- Anthony Meza
- Department of Biochemistry, University of Wisconsin−Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Meghan E. Campbell
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Anna Zmich
- Department of Biochemistry, University of Wisconsin−Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
| | - Sierra A. Thein
- Chemistry Department, Ripon College, 300 W Seward St., Ripon, Wisconsin 54971, United States
| | - Abbigail M. Grieger
- Chemistry Department, Ripon College, 300 W Seward St., Ripon, Wisconsin 54971, United States
| | - Matthew J. McGill
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Patrick H. Willoughby
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Chemistry Department, Ripon College, 300 W Seward St., Ripon, Wisconsin 54971, United States
| | - Andrew R. Buller
- Department of Biochemistry, University of Wisconsin−Madison, 433 Babcock Drive, Madison, Wisconsin 53706, United States
- Department of Chemistry, University of Wisconsin−Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Smith JL, Madrigal Harrison I, Bingman C, Buller AR. Investigation of β-substitution activity of O-acetylserine sulfhydrolase from Citrullus vulgaris. Chembiochem 2022; 23:e202200157. [PMID: 35476889 PMCID: PMC9401013 DOI: 10.1002/cbic.202200157] [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: 03/20/2022] [Revised: 04/24/2022] [Indexed: 11/17/2022]
Abstract
Pyridoxal‐5’‐phosphate (PLP)‐dependent enzymes have garnered interest for their ability to synthesize non‐standard amino acids (nsAAs). One such class of enzymes, O‐acetylserine sulfhydrylases (OASSs), catalyzes the final step in the biosynthesis of l‐cysteine. Here, we examine the β‐substitution capability of the OASS from Citrullus vulgaris (CvOASS), a putative l‐mimosine synthase. While the previously reported mimosine synthase activity was not reproducible in our hands, we successfully identified non‐native reactivity with a variety of O‐nucleophiles. Optimization of reaction conditions for carboxylate and phenolate substrates led to distinct conditions that were leveraged for the preparative‐scale synthesis of nsAAs. We further show this enzyme is capable of C−C bond formation through a β‐alkylation reaction with an activated nitroalkane. To facilitate understanding of this enzyme, we determined the crystal structure of the enzyme bound to PLP as the internal aldimine at 1.55 Å, revealing key features of the active site and providing information that may guide subsequent development of CvOASS as a practical biocatalyst.
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Affiliation(s)
| | | | - Craig Bingman
- University of Wisconsin-Madison, Biochemistry, UNITED STATES
| | - Andrew Richard Buller
- University of Wisconsin Madison, Chemistry, 1101 University Ave, 53706, Madison, UNITED STATES
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