1
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Farajollahi S, Lombardo NV, Crenshaw MD, Guo HB, Doherty ME, Davison TR, Steel JJ, Almand EA, Varaljay VA, Suei-Hung C, Mirau PA, Berry RJ, Kelley-Loughnane N, Dennis PB. Defluorination of Organofluorine Compounds Using Dehalogenase Enzymes from Delftia acidovorans (D4B). ACS OMEGA 2024; 9:28546-28555. [PMID: 38973860 PMCID: PMC11223199 DOI: 10.1021/acsomega.4c02517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 07/09/2024]
Abstract
Organofluorine compounds have been widely used as pharmaceuticals, agricultural pesticides, and water-resistant coatings for decades; however, these compounds are recognized as environmental pollutants. The capability of microorganisms and enzymes to defluorinate organofluorine compounds is both rare and highly desirable to facilitate environmental remediation efforts. Recently, a strain of Delftia acidovorans (D4B) was identified with potential biodegradation activity toward perfluoroalkyl substances (PFAS) and other organofluorine compounds. Genomic analysis found haloacid and fluoroacetate dehalogenases as enzymes associated with Delftia acidovorans. Here, defluorination activity of these enzymes toward different fluorinated substrates was investigated after their recombinant expression and purification from E. coli. Using an electrochemical fluoride probe, 19F NMR, and mass spectrometry to monitor defluorination, we identified two dehalogenases, DeHa2 (a haloacid dehalogenase) and DeHa4 (a fluoroacetate dehalogenase), with activity toward mono- and difluoroacetate. Of the two dehalogenases, DeHa4 demonstrated a low pH optimum compared to DeHa2, which lost catalytic activity under acidic conditions. DeHa2 and DeHa4 are relatively small proteins, operate under aerobic conditions, and remain active for days in the presence of substrates. Significantly, while there have been many reports on dehalogenation of monofluoroacetate by dehalogenases, this study adds to the relatively small list of enzymes reported to carry out enzymatic defluorination of the more recalcitrant disubstituted carbon in an organofluorine compound. Thus, DeHa2 and DeHa4 represent organofluorine dehalogenases that may be used in the future to design and engineer robust defluorination agents for environmental remediation efforts.
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Affiliation(s)
- Sanaz Farajollahi
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
| | - Nina V. Lombardo
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
- UES
a BlueHalo Company, 4401
Dayton-Xenia Rd., Dayton, Ohio United States 45432-1894
| | - Michael D. Crenshaw
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
- UES
a BlueHalo Company, 4401
Dayton-Xenia Rd., Dayton, Ohio United States 45432-1894
| | - Hao-Bo Guo
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
- UES
a BlueHalo Company, 4401
Dayton-Xenia Rd., Dayton, Ohio United States 45432-1894
| | - Megan E. Doherty
- Department
of Biology, United States Air Force Academy, Colorado Springs, Colorado United States 80840-5002
| | - Tina R. Davison
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
- UES
a BlueHalo Company, 4401
Dayton-Xenia Rd., Dayton, Ohio United States 45432-1894
| | - Jordan J. Steel
- Department
of Biology, United States Air Force Academy, Colorado Springs, Colorado United States 80840-5002
| | - Erin A. Almand
- Department
of Biology, United States Air Force Academy, Colorado Springs, Colorado United States 80840-5002
| | - Vanessa A. Varaljay
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
- The
Ohio State University, Infectious Diseases
Institute, Columbus, Ohio United States 43210-1132
| | - Chia Suei-Hung
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
| | - Peter A. Mirau
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
| | - Rajiv J. Berry
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
| | - Nancy Kelley-Loughnane
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
| | - Patrick B. Dennis
- Air
Force Research Laboratory, Materials and Manufacturing Directorate, 2179 12th Street, WPAFB, Ohio United States 45433-7131
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2
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Zhang Y, Mokkawes T, de Visser SP. Insights into Cytochrome P450 Enzyme Catalyzed Defluorination of Aromatic Fluorides. Angew Chem Int Ed Engl 2023; 62:e202310785. [PMID: 37641517 DOI: 10.1002/anie.202310785] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Density functional calculations establish a novel mechanism of aromatic defluorination by P450 Compound I. This is achieved via either an initial epoxide intermediate or through a 1,2-fluorine shift in an electrophilic intermediate, which highlights that the P450s can defluorinate fluoroarenes. However, in the absence of a proton donor a strong Fe-F bond can be obtained as shown from the calculations.
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Affiliation(s)
- Yi Zhang
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Thirakorn Mokkawes
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Sam P de Visser
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M17DN, UK
- Department of Chemical Engineering, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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3
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Rogers MS, Gordon AM, Rappe TM, Goodpaster JD, Lipscomb JD. Contrasting Mechanisms of Aromatic and Aryl-Methyl Substituent Hydroxylation by the Rieske Monooxygenase Salicylate 5-Hydroxylase. Biochemistry 2023; 62:507-523. [PMID: 36583545 PMCID: PMC9854337 DOI: 10.1021/acs.biochem.2c00610] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The hydroxylase component (S5HH) of salicylate-5-hydroxylase catalyzes C5 ring hydroxylation of salicylate but switches to methyl hydroxylation when a C5 methyl substituent is present. The use of 18O2 reveals that both aromatic and aryl-methyl hydroxylations result from monooxygenase chemistry. The functional unit of S5HH comprises a nonheme Fe(II) site located 12 Å across a subunit boundary from a one-electron reduced Rieske-type iron-sulfur cluster. Past studies determined that substrates bind near the Fe(II), followed by O2 binding to the iron to initiate catalysis. Stopped-flow-single-turnover reactions (STOs) demonstrated that the Rieske cluster transfers an electron to the iron site during catalysis. It is shown here that fluorine ring substituents decrease the rate constant for Rieske electron transfer, implying a prior reaction of an Fe(III)-superoxo intermediate with a substrate. We propose that the iron becomes fully oxidized in the resulting Fe(III)-peroxo-substrate-radical intermediate, allowing Rieske electron transfer to occur. STO using 5-CD3-salicylate-d8 occurs with an inverse kinetic isotope effect (KIE). In contrast, STO of a 1:1 mixture of unlabeled and 5-CD3-salicylate-d8 yields a normal product isotope effect. It is proposed that aromatic and aryl-methyl hydroxylation reactions both begin with the Fe(III)-superoxo reaction with a ring carbon, yielding the inverse KIE due to sp2 → sp3 carbon hybridization. After Rieske electron transfer, the resulting Fe(III)-peroxo-salicylate intermediate can continue to aromatic hydroxylation, whereas the equivalent aryl-methyl intermediate formation must be reversible to allow the substrate exchange necessary to yield a normal product isotope effect. The resulting Fe(III)-(hydro)peroxo intermediate may be reactive or evolve through a high-valent iron intermediate to complete the aryl-methyl hydroxylation.
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Affiliation(s)
- Melanie S. Rogers
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Adrian M. Gordon
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Todd M. Rappe
- Minnesota NMR Center, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Jason D. Goodpaster
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology, and Biophysics and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States
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4
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Tetramethylammonium Fluoride: Fundamental Properties and Applications in C-F Bond-Forming Reactions and as a Base. Catalysts 2022. [DOI: 10.3390/catal12020233] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nucleophilic ionic sources of fluoride are essential reagents in the synthetic toolbox to access high added-value fluorinated building blocks unattainable by other means. In this review, we provide a concise description and rationale of the outstanding features of one of these reagents, tetramethylammonium fluoride (TMAF), as well as disclosing the different methods for its preparation, and how its physicochemical properties and solvation effects in different solvents are intimately associated with its reactivity. Furthermore, herein we also comprehensively describe its historic and recent utilization, up to December 2021, in C-F bond-forming reactions with special emphasis on nucleophilic aromatic substitution fluorinations with a potential sustainable application in industrial settings, as well as its use as a base capable of rendering unprecedented transformations.
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5
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Alexandrino DAM, Almeida CMR, Mucha AP, Carvalho MF. Revisiting pesticide pollution: The case of fluorinated pesticides. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 292:118315. [PMID: 34634397 DOI: 10.1016/j.envpol.2021.118315] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/11/2021] [Accepted: 10/06/2021] [Indexed: 06/13/2023]
Abstract
Fluorinated pesticides acquired a significant market share in the agrochemical sector due to the surge of new fluoroorganic ingredients approved in the last two decades. This growing trend has not been accompanied by a comprehensive scientific and regulatory framework entailing all their potential negative impacts for the environment, especially when considering the hazardous properties that may result from the incorporation of fluorine into organic molecules. This review aims to address the safe/hazardous dichotomy associated with fluorinated pesticides by providing an updated outlook on their relevancy in the agrochemical sector and how it leads to their role as environmental pollutants. Specifically, the environmental fate and distribution of these pesticides in the ecosystems is discussed, while also analysing their potential to act as toxic substances for non-target organisms.
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Affiliation(s)
- Diogo A M Alexandrino
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos s/n, 4450-208, Matosinhos, Portugal; School of Medicine and Biomedical Sciences (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.
| | - C Marisa R Almeida
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Ana P Mucha
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos s/n, 4450-208, Matosinhos, Portugal; Faculty of Sciences, University of Porto, Rua do Campo Alegre 790, 4150-171, Porto, Portugal
| | - Maria F Carvalho
- CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos s/n, 4450-208, Matosinhos, Portugal; School of Medicine and Biomedical Sciences (ICBAS), University of Porto, Rua de Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal
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6
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Huang Q, Zhang X, Chen Q, Tian S, Tong W, Zhang W, Chen Y, Ma M, Chen B, Wang B, Wang JB. Discovery of a P450-Catalyzed Oxidative Defluorination Mechanism toward Chiral Organofluorines: Uncovering a Hidden Pathway. ACS Catal 2021. [DOI: 10.1021/acscatal.1c05510] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Qun Huang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Xuan Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 360015 Xiamen, People’s Republic of China
| | - Qianqian Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 360015 Xiamen, People’s Republic of China
| | - Shaixiao Tian
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Wei Tong
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Wei Zhang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Yingzhuang Chen
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Ming Ma
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Bo Chen
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 360015 Xiamen, People’s Republic of China
| | - Jian-bo Wang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education) and Key Laboratory of Phytochemistry R&D of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, 410081 Changsha, People’s Republic of China
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7
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Affiliation(s)
- Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) Universitat de Girona C/Mª Aurèlia Capmany 69 17003 Girona Catalonia Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC) Universitat de Girona C/Mª Aurèlia Capmany 69 17003 Girona Catalonia Spain
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8
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Khan MF, Murphy CD. Bacterial degradation of the anti-depressant drug fluoxetine produces trifluoroacetic acid and fluoride ion. Appl Microbiol Biotechnol 2021; 105:9359-9369. [PMID: 34755212 DOI: 10.1007/s00253-021-11675-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 11/28/2022]
Abstract
Fluoxetine (FLX) is a blockbuster drug with annual sales in the billions of dollars. Its widespread use has resulted in its detection in water courses, where it impacts aquatic life. Investigations on the biodegradation of FLX by microorganisms are important, since augmentation of secondary wastewater treatment by an effective degrader may be one method of improving the drug's removal. In this paper, we demonstrate that common environmental bacteria can use FLX as a sole carbon and energy source. Investigations into the metabolites formed using fluorine-19 nuclear magnetic resonance spectroscopy (19F NMR) and gas chromatography-mass spectrometry indicated that the drug was initially hydrolysed to yield 4-(trifluoromethyl)phenol (TFMP) and 3-(methylamino)-1-phenylpropan-1-ol. Since the fluorometabolite accumulated, the bacteria presumably used the latter compound for carbon and energy. Further growth studies revealed that TFMP could also be used as a sole carbon and energy source and was most likely catabolised via meta-cleavage, since semialdehyde products were detected in culture supernatants. The final products of the degradation pathway were trifluoroacetate and fluoride ion; the former is a dead-end product and was not further catabolised. Fluoride ion most likely arises owing to spontaneous defluorination of the meta-cleavage products that were shown to be photolabile.Key points• Bacteria can use FLX and TFMP as sole carbon and energy sources for their growth.• Biodegradation produces fluorometabolites that were detected by 19F NMR and GC-MS.• Trifluoroacetic acid and fluoride ion were identified as end products.
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Affiliation(s)
- Mohd Faheem Khan
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac D Murphy
- UCD School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland.
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9
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Cheng X, Ma L. Enzymatic synthesis of fluorinated compounds. Appl Microbiol Biotechnol 2021; 105:8033-8058. [PMID: 34625820 PMCID: PMC8500828 DOI: 10.1007/s00253-021-11608-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 12/31/2022]
Abstract
Fluorinated compounds are widely used in the fields of molecular imaging, pharmaceuticals, and materials. Fluorinated natural products in nature are rare, and the introduction of fluorine atoms into organic compound molecules can give these compounds new functions and make them have better performance. Therefore, the synthesis of fluorides has attracted more and more attention from biologists and chemists. Even so, achieving selective fluorination is still a huge challenge under mild conditions. In this review, the research progress of enzymatic synthesis of fluorinated compounds is summarized since 2015, including cytochrome P450 enzymes, aldolases, fluoroacetyl coenzyme A thioesterases, lipases, transaminases, reductive aminases, purine nucleoside phosphorylases, polyketide synthases, fluoroacetate dehalogenases, tyrosine phenol-lyases, glycosidases, fluorinases, and multienzyme system. Of all enzyme-catalyzed synthesis methods, the direct formation of the C-F bond by fluorinase is the most effective and promising method. The structure and catalytic mechanism of fluorinase are introduced to understand fluorobiochemistry. Furthermore, the distribution, applications, and future development trends of fluorinated compounds are also outlined. Hopefully, this review will help researchers to understand the significance of enzymatic methods for the synthesis of fluorinated compounds and find or create excellent fluoride synthase in future research.Key points• Fluorinated compounds are distributed in plants and microorganisms, and are used in imaging, medicine, materials science.• Enzyme catalysis is essential for the synthesis of fluorinated compounds.• The loop structure of fluorinase is the key to forming the C-F bond.
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Affiliation(s)
- Xinkuan Cheng
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology, College of Biotechnology, Tianjin University of Science & Technology, No. 29, Thirteenth Street, Binhai New District, Tianjin, 300457, China
| | - Long Ma
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Laboratory of Metabolic Control Fermentation Technology, College of Biotechnology, Tianjin University of Science & Technology, No. 29, Thirteenth Street, Binhai New District, Tianjin, 300457, China.
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10
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Xu J, Lou Y, Wang L, Wang Z, Xu W, Ma W, Chen Z, Chen X, Wu Q. Rational Design of Biocatalytic Deuteration Platform of Aldehydes. ACS Catal 2021. [DOI: 10.1021/acscatal.1c03659] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Jian Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou 310014, People’s Republic of China
| | - Yujiao Lou
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Lanlan Wang
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Zhiguo Wang
- Institute of Aging Research, School of Medicine, Hangzhou Normal University, Hangzhou 311121, People’s Republic of China
| | - Weihua Xu
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Wenqian Ma
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, People’s Republic of China
| | - Zhichun Chen
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Xiaoyang Chen
- College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, 314001, People’s Republic of China
| | - Qi Wu
- Center of Chemistry for Frontier Technologies, Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
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11
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Meyer S, Häfliger J, Gilmour R. Expanding organofluorine chemical space: the design of chiral fluorinated isosteres enabled by I(i)/I(iii) catalysis. Chem Sci 2021; 12:10686-10695. [PMID: 34476053 PMCID: PMC8372324 DOI: 10.1039/d1sc02880d] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 06/28/2021] [Indexed: 12/12/2022] Open
Abstract
Short aliphatic groups are prevalent in bioactive small molecules and play an essential role in regulating physicochemistry and molecular recognition phenomena. Delineating their biological origins and significance have resulted in landmark developments in synthetic organic chemistry: Arigoni's venerable synthesis of the chiral methyl group is a personal favourite. Whilst radioisotopes allow the steric footprint of the native group to be preserved, this strategy was never intended for therapeutic chemotype development. In contrast, leveraging H → F bioisosterism provides scope to complement the chiral, radioactive bioisostere portfolio and to reach unexplored areas of chiral chemical space for small molecule drug discovery. Accelerated by advances in I(i)/I(iii) catalysis, the current arsenal of achiral 2D and 3D drug discovery modules is rapidly expanding to include chiral units with unprecedented topologies and van der Waals volumes. This Perspective surveys key developments in the design and synthesis of short multivicinal fluoroalkanes under the auspices of main group catalysis paradigms.
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Affiliation(s)
- Stephanie Meyer
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Correnstraße 36 48149 Münster Germany
| | - Joel Häfliger
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Correnstraße 36 48149 Münster Germany
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster Correnstraße 36 48149 Münster Germany
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12
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Yue Y, Fan J, Xin G, Huang Q, Wang JB, Li Y, Zhang Q, Wang W. Comprehensive Understanding of Fluoroacetate Dehalogenase-Catalyzed Degradation of Fluorocarboxylic Acids: A QM/MM Approach. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9817-9825. [PMID: 34080849 DOI: 10.1021/acs.est.0c08811] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fluorochemicals are persistent, bioaccumulative, and toxic compounds that are widely tributed in the environment. Developing efficient biodegradation strategies to decompose the fluorochemicals via breaking the inert C-F bonds presents a holistic challenge. As a promising biodegradation enzyme candidate, fluoroacetate dehalogenase (FAcD) has been reported as the only non-metallic enzyme to catalyze the cleavage of the strong C-F bond. Here, we systematically investigated the catalytic actions of FAcD toward its natural substrate fluoroacetate using molecular dynamics simulations and quantum mechanism/molecular mechanism calculations. We propose that the enzymatic transformation involves four elementary steps, (I) C-F bond activation, (II) nucleophilic attack, (III) C-O bond cleavage, and (IV) proton transfer. Our results show that nucleophilic attack is the rate-determining step. However, for difluoroacetate and trifluoroacetate, C-F bond activation, instead of nucleophilic attack, becomes the rate-determining step. We show that FAcD, originally recognized as α-fluorocarboxylic acid degradation enzyme, can catalyze the defluorination of difluoroacetate to glyoxylate, which is captured by our high-resolution mass spectrometry experiments. In addition, we employed amino acid electrostatic analysis method to screen potential mutation hotspots for tuning FAcD's electrostatic environment to favor substrate conversion. The comprehensive understanding of catalytic mechanism will inform a rational enzyme engineering strategy to degrade fluorochemicals for benefits of environmental sustainability.
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Affiliation(s)
- Yue Yue
- Environment Research Institute, Shandong University, Qingdao 266237, P. R. China
| | - Jiaqian Fan
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China
| | - Guoqing Xin
- Wuhan National High Magnetic Field Center (WHMFC), Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Qun Huang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China
| | - Jian-Bo Wang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, P. R. China
| | - Yanwei Li
- Environment Research Institute, Shandong University, Qingdao 266237, P. R. China
| | - Qingzhu Zhang
- Environment Research Institute, Shandong University, Qingdao 266237, P. R. China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Qingdao 266237, P. R. China
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13
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Wang Y, Davis I, Shin I, Xu H, Liu A. Molecular Rationale for Partitioning between C-H and C-F Bond Activation in Heme-Dependent Tyrosine Hydroxylase. J Am Chem Soc 2021; 143:4680-4693. [PMID: 33734681 DOI: 10.1021/jacs.1c00175] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The heme-dependent l-tyrosine hydroxylases (TyrHs) in natural product biosynthesis constitute a new enzyme family in contrast to the nonheme iron enzymes for DOPA production. A representative TyrH exhibits dual reactivity of C-H and C-F bond cleavage when challenged with 3-fluoro-l-tyrosine (3-F-Tyr) as a substrate. However, little is known about how the enzyme mediates two distinct reactions. Herein, a new TyrH from the thermophilic bacterium Streptomyces sclerotialus (SsTyrH) was functionally and structurally characterized. A de novo crystal structure of the enzyme-substrate complex at 1.89-Å resolution provides the first comprehensive structural study of this hydroxylase. The binding conformation of l-tyrosine indicates that C-H bond hydroxylation is initiated by electron transfer. Mutagenesis studies confirmed that an active site histidine, His88, participates in catalysis. We also obtained a 1.68-Å resolution crystal structure in complex with the monofluorinated substrate, 3-F-Tyr, which shows one binding conformation but two orientations of the fluorine atom with a ratio of 7:3, revealing that the primary factor of product distribution is the substrate orientation. During in crystallo reaction, a ferric-hydroperoxo intermediate (compound 0, Fe3+-OOH) was observed with 3-F-Tyr as a substrate based on characteristic spectroscopic features. We determined the crystal structure of this compound 0-type intermediate and refined it to 1.58-Å resolution. Collectively, this study provided the first molecular details of the heme-dependent TyrH and determined the primary factor that dictates the partitioning between the dual reactivities of C-H and C-F bond activation.
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Affiliation(s)
- Yifan Wang
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, Texas 78249, United States
| | - Ian Davis
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, Texas 78249, United States
| | - Inchul Shin
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, Texas 78249, United States
| | - Hui Xu
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, Texas 78249, United States
| | - Aimin Liu
- Department of Chemistry, The University of Texas at San Antonio, One UTSA Circle, Texas 78249, United States
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