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Li X, Li C, Qu G, Yuan B, Sun Z. Engineering of a Baeyer-Villiger monooxygenase to Improve Substrate Scope, Stereoselectivity and Regioselectivity. Chembiochem 2024; 25:e202400328. [PMID: 38742991 DOI: 10.1002/cbic.202400328] [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: 04/09/2024] [Revised: 05/12/2024] [Accepted: 05/14/2024] [Indexed: 05/16/2024]
Abstract
Baeyer-Villiger monooxygenases belong to a family of flavin-binding proteins that catalyze the Baeyer-Villiger (BV) oxidation of ketones to produce lactones or esters, which are important intermediates in pharmaceuticals or sustainable materials. Phenylacetone monooxygenase (PAMO) from Thermobifida fusca with moderate thermostability catalyzes the oxidation of aryl ketone substrates, but is limited by high specificity and narrow substrate scope. In the present study, we applied loop optimization by loop swapping followed by focused saturation mutagenesis in order to evolve PAMO mutants capable of catalyzing the regioselective BV oxidation of cyclohexanone and cyclobutanone derivatives with formation of either normal or abnormal esters or lactones. We further modulated PAMO to increase enantioselectivity. Crystal structure studies indicate that rotation occurs in the NADP-binding domain and that the high B-factor region is predominantly distributed in the catalytic pocket residues. Computational analyses further revealed dynamic character in the catalytic pocket and reshaped hydrogen bond interaction networks, which is more favorable for substrate binding. Our study provides useful insights for studying enzyme-substrate adaptations.
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Affiliation(s)
- Xu Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
| | - Congcong Li
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
| | - Ge Qu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
| | - Bo Yuan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
| | - Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
- Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, PR China
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2
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Furukawa T, Kushiro M, Nakagawa H, Enomoto H, Sakuda S. Low-dose ethanol increases aflatoxin production due to the adh1-dependent incorporation of ethanol into aflatoxin biosynthesis. iScience 2023; 26:106051. [PMID: 36818304 PMCID: PMC9932502 DOI: 10.1016/j.isci.2023.106051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 12/09/2022] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
Aflatoxins are toxic secondary metabolites produced by some aspergilli, including Aspergillus flavus. Recently, ethanol has attracted attention as an agent for the control of aflatoxin contamination. However, as aflatoxin biosynthesis utilizes acetyl coenzyme A, ethanol may be conversely exploited for aflatoxin production. Here, we demonstrated that not only the 13C of labeled ethanol, but also that of labeled 2-propanol, was incorporated into aflatoxin B1 and B2, and that ethanol and 2-propanol upregulated aflatoxin production at low concentrations (<1% and <0.6%, respectively). In the alcohol dehydrogenase gene adh1 deletion mutant, the 13C incorporation of labeled ethanol, but not labeled 2-propanol, into aflatoxin B1 and B2 was attenuated, indicating that the alcohols have different utilization pathways. Our results show that A. flavus utilizes ethanol and 2-propanol as carbon sources for aflatoxin biosynthesis and that adh1 indirectly controls aflatoxin production by balancing ethanol production and catabolism.
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Affiliation(s)
- Tomohiro Furukawa
- Institute of Food Research, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan,Corresponding author
| | - Masayo Kushiro
- Institute of Food Research, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan
| | - Hiroyuki Nakagawa
- Research Center for Advanced Analysis, NARO, 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan
| | - Hirofumi Enomoto
- Department of Biosciences, Faculty of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan,Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan
| | - Shohei Sakuda
- Department of Biosciences, Faculty of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan
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3
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Perera M, Wijesundera S, Wijayarathna CD, Seneviratne G, Jayasena S. Identification of long-chain alkane-degrading (LadA) monooxygenases in Aspergillus flavus via in silico analysis. Front Microbiol 2022; 13:898456. [PMID: 36110294 PMCID: PMC9468676 DOI: 10.3389/fmicb.2022.898456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/20/2022] [Indexed: 11/25/2022] Open
Abstract
Efficient degradation of alkanes in crude oil by the isolated Aspergillus flavus MM1 alluded to the presence of highly active alkane-degrading enzymes in this fungus. A long-chain alkane-degrading, LadA-like enzyme family in A. flavus was identified, and possible substrate-binding modes were analyzed using a computational approach. By analyzing publicly available protein databases, we identified six uncharacterized proteins in A. flavus NRRL 3357, of which five were identified as class LadAα and one as class LadAβ, which are eukaryotic homologs of bacterial long-chain alkane monooxygenase (LadA). Computational models of A. flavus LadAα homologs (Af1-Af5) showed overall structural similarity to the bacterial LadA and the unique sequence and structural elements that bind the cofactor Flavin mononucleotide (FMN). A receptor-cofactor-substrate docking protocol was established and validated to demonstrate the substrate binding in the A. flavus LadAα homologs. The modeled Af1, Af3, Af4, and Af5 captured long-chain n-alkanes inside the active pocket, above the bound FMN. Isoalloxazine ring of reduced FMN formed a π–alkyl interaction with the terminal carbon atom of captured alkanes, C16–C30, in Af3–Af5 and C16–C24 in Af1. Our results confirmed the ability of identified A. flavus LadAα monooxygenases to bind long-chain alkanes inside the active pocket. Hence A. flavus LadAα monooxygenases potentially initiate the degradation of long-chain alkanes by oxidizing bound long-chain alkanes into their corresponding alcohol.
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Affiliation(s)
- Madushika Perera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | - Sulochana Wijesundera
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
| | | | | | - Sharmila Jayasena
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka
- *Correspondence: Sharmila Jayasena,
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4
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Phelan RM, Abrahamson MJ, Brown JTC, Zhang RK, Zwick CR. Development of Scalable Processes with Underutilized Biocatalyst Classes. Org Process Res Dev 2022. [DOI: 10.1021/acs.oprd.1c00467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryan M. Phelan
- Process Research and Development, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Michael J. Abrahamson
- Operations Science and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Jesse T. C. Brown
- Process Research and Development, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Ruijie K. Zhang
- Discovery Chemistry and Technology, AbbVie Inc., North Chicago, Illinois 60064, United States
| | - Christian R. Zwick
- Process Research and Development, AbbVie Inc., North Chicago, Illinois 60064, United States
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5
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Qi F, Zhang W, Xue Y, Geng C, Huang X, Sun J, Lu X. Bienzyme-Catalytic and Dioxygenation-Mediated Anthraquinone Ring Opening. J Am Chem Soc 2021; 143:16326-16331. [PMID: 34586791 DOI: 10.1021/jacs.1c07182] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The C-10-C-4a bond cleavage of anthraquinone is believed to be a crucial step in fungal seco-anthraquinone biosynthesis and has long been proposed as a classic Baeyer-Villiger oxidation. Nonetheless, genetic, enzymatic, and chemical information on ring opening remains elusive. Here, a revised questin ring-opening mechanism was elucidated by in vivo gene disruption, in vitro enzymatic analysis, and 18O chasing experiments. It has been confirmed that the reductase GedF is responsible for the reduction of the keto group at C-10 in questin to a hydroxyl group with the aid of NADPH. The C-10-C-4a bond of the resultant questin hydroquinone is subsequently cleaved by the atypical cofactor-free dioxygenase GedK, giving rise to desmethylsulochrin. This proposed bienzyme-catalytic and dioxygenation-mediated anthraquinone ring-opening reaction shows universality.
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Affiliation(s)
- Feifei Qi
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
| | - Wei Zhang
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingying Xue
- International Centre for Bamboo and Rattan, State Forestry Administration Key Open Laboratory, Beijing 100102, China
| | - Ce Geng
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
| | - Xuenian Huang
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jia Sun
- International Centre for Bamboo and Rattan, State Forestry Administration Key Open Laboratory, Beijing 100102, China
| | - Xuefeng Lu
- Shandong Provincial Key Laboratory of Synthetic Biology, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- Shandong Energy Institute, Qingdao, Shandong 266101, China
- Qingdao New Energy Shandong Laboratory, Qingdao, Shandong 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Marine Biology and Biotechnology Laboratory, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266101, China
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6
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Valentino H, Sobrado P. Characterization of a Nitro-Forming Enzyme Involved in Fosfazinomycin Biosynthesis. Biochemistry 2021; 60:2851-2864. [PMID: 34516102 DOI: 10.1021/acs.biochem.1c00512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-hydroxylating monooxygenases (NMOs) are a subclass of flavin-dependent enzymes that hydroxylate nitrogen atoms. Recently, unique NMOs that perform multiple reactions on one substrate molecule have been identified. Fosfazinomycin M (FzmM) is one such NMO, forming nitrosuccinate from aspartate (Asp) in the fosfazinomycin biosynthetic pathway in some Streptomyces sp. This work details the biochemical and kinetic analysis of FzmM. Steady-state kinetic investigation shows that FzmM performs a coupled reaction with Asp (kcat, 3.0 ± 0.01 s-1) forming nitrosuccinate, which can be converted to fumarate and nitrite by the action of FzmL. FzmM displays a 70-fold higher kcat/KM value for NADPH compared to NADH and has a narrow optimal pH range (7.5-8.0). Contrary to other NMOs where the kred is rate-limiting, FzmM exhibits a very fast kred (50 ± 0.01 s-1 at 4 °C) with NADPH. NADPH binds at a KD value of ∼400 μM, and hydride transfer occurs with pro-R stereochemistry. Oxidation of FzmM in the absence of Asp exhibits a spectrum with a shoulder at ∼370 nm, consistent with the formation of a C(4a)-hydroperoxyflavin intermediate, which decays into oxidized flavin and hydrogen peroxide at a rate 100-fold slower than the kcat. This reaction is enhanced in the presence of Asp with a slightly faster kox than the kcat, suggesting that flavin dehydration or Asp oxidation is partially rate limiting. Multiple sequence analyses of FzmM to NMOs identified conserved residues involved in flavin binding but not for NADPH. Additional sequence analysis to related monooxygenases suggests that FzmM shares sequence motifs absent in other NMOs.
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Affiliation(s)
- Hannah Valentino
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.,Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Pablo Sobrado
- Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, United States.,Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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7
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Bretschneider L, Heuschkel I, Ahmed A, Bühler K, Karande R, Bühler B. Characterization of different biocatalyst formats for BVMO-catalyzed cyclohexanone oxidation. Biotechnol Bioeng 2021; 118:2719-2733. [PMID: 33844297 DOI: 10.1002/bit.27791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/03/2021] [Accepted: 04/04/2021] [Indexed: 01/05/2023]
Abstract
Cyclohexanone monooxygenase (CHMO), a member of the Baeyer-Villiger monooxygenase family, is a versatile biocatalyst that efficiently catalyzes the conversion of cyclic ketones to lactones. In this study, an Acidovorax-derived CHMO gene was expressed in Pseudomonas taiwanensis VLB120. Upon purification, the enzyme was characterized in vitro and shown to feature a broad substrate spectrum and up to 100% conversion in 6 h. Furthermore, we determined and compared the cyclohexanone conversion kinetics for different CHMO-biocatalyst formats, that is, isolated enzyme, suspended whole cells, and biofilms, the latter two based on recombinant CHMO-containing P. taiwanensis VLB120. Biofilms showed less favorable values for KS (9.3-fold higher) and kcat (4.8-fold lower) compared with corresponding KM and kcat values of isolated CHMO, but a favorable KI for cyclohexanone (5.3-fold higher). The unfavorable KS and kcat values are related to mass transfer- and possibly heterogeneity issues and deserve further investigation and engineering, to exploit the high potential of biofilms regarding process stability. Suspended cells showed only 1.8-fold higher KS , but 1.3- and 4.2-fold higher kcat and KI values than isolated CHMO. This together with the efficient NADPH regeneration via glucose metabolism makes this format highly promising from a kinetics perspective.
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Affiliation(s)
- Lisa Bretschneider
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ingeborg Heuschkel
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Afaq Ahmed
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Katja Bühler
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Rohan Karande
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Bruno Bühler
- Department of Solar Materials, Helmholtz-Centre for Environmental Research - UFZ, Leipzig, Germany
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8
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Ebrecht AC, Aschenbrenner JC, Smit MS, Opperman DJ. Biocatalytic synthesis of non-vicinal aliphatic diols. Org Biomol Chem 2021; 19:439-445. [PMID: 33331366 DOI: 10.1039/d0ob02086a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Biocatalysts are receiving increased attention in the field of selective oxyfunctionalization of C-H bonds, with cytochrome P450 monooxygenases (CYP450s), and the related peroxygenases, leading the field. Here we report on the substrate promiscuity of CYP505A30, previously characterized as a fatty acid hydroxylase. In addition to its regioselective oxyfunctionalization of saturated fatty acids (ω-1 - ω-3 hydroxylation), primary fatty alcohols are also accepted with similar regioselectivities. Moreover, alkanes such as n-octane and n-decane are also readily accepted, allowing for the production of non-vicinal diols through sequential oxygenation.
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Affiliation(s)
- Ana C Ebrecht
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa.
| | - Jasmin C Aschenbrenner
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa. and South African DST-NRF Centre of Excellence in Catalysis, c*change, South Africa
| | - Martha S Smit
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa. and South African DST-NRF Centre of Excellence in Catalysis, c*change, South Africa
| | - Diederik J Opperman
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa.
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9
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Aschenbrenner JC, Ebrecht AC, Tolmie C, Smit MS, Opperman DJ. Structure of the fungal hydroxylase, CYP505A30, and rational transfer of mutation data from CYP102A1 to alter regioselectivity. Catal Sci Technol 2021. [DOI: 10.1039/d1cy01348c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Regioselective oxyfunctionalisation of n-alkanes and production of non-vicinal diols by evolved CYP505A30 through rational transfer of knowledge between protein scaffolds.
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Affiliation(s)
- Jasmin C. Aschenbrenner
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
- South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, South Africa
| | - Ana C. Ebrecht
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
| | - Carmien Tolmie
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
| | - Martha S. Smit
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
- South African DST-NRF Centre of Excellence in Catalysis, c*change, University of Cape Town, South Africa
| | - Diederik J. Opperman
- Department of Microbiology and Biochemistry, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
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10
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Ceccoli RD, Bianchi DA, Carabajal MA, Rial DV. Genome mining reveals new bacterial type I Baeyer-Villiger monooxygenases with (bio)synthetic potential. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.110875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Reyes-Sánchez FJ, Páez-Lerma JB, Rojas-Contreras JA, López-Miranda J, Soto-Cruz NÓ, Reinhart-Kirchmayr M. Study of the Enzymatic Capacity of Kluyveromyces marxianus for the Synthesis of Esters. J Mol Microbiol Biotechnol 2020; 29:1-9. [PMID: 32325454 DOI: 10.1159/000507551] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 03/24/2020] [Indexed: 11/19/2022] Open
Abstract
Recently, biotechnological opportunities have been found in non-Saccharomyces yeasts because they possess metabolic characteristics that lead to the production of compounds of interest. It has been observed that Kluyveromyces marxianus has a great potential in the production of esters, which are aromatic compounds of industrial importance. The genetic bases that govern the synthesis of esters include a large group of enzymes, among which the most important are alcohol acetyl transferases (AATases) and esterases (AEATases), and it is known that some are present in K. marxianus, because it has genetic characteristics like S. cerevisiae. It also has a physiology suitable for biotechnological use since it is the eukaryotic microorganism with the fastest growth rate and has a wide range of thermotolerance with respect to other yeasts. In this work, the enzymatic background of K. marxianus involved in the synthesis of esters is analyzed, based on the sequences reported in the NCBI database.
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Affiliation(s)
| | | | | | - Javier López-Miranda
- Chemistry and Biochemistry, TECNM/Instituto Tecnológico de Durango, Durango, Mexico
| | | | - Manuel Reinhart-Kirchmayr
- Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco A.C., Guadalajara, Mexico
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12
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Natural Variation in the ‘Control Loop’ of BVMOAFL210 and Its Influence on Regioselectivity and Sulfoxidation. Catalysts 2020. [DOI: 10.3390/catal10030339] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Baeyer-Villiger monooxygenases (BVMOs) are flavin-dependent enzymes that primarily convert ketones to esters, but can also catalyze heteroatom oxidation. Several structural studies have highlighted the importance of the ‘control loop’ in BVMOs, which adopts different conformations during catalysis. Central to the ‘control loop’ is a conserved tryptophan that has been implicated in NADP(H) binding. BVMOAFL210 from Aspergillus flavus, however, contains a threonine in the equivalent position. Here, we report the structure of BVMOAFL210 in complex with NADP+ in both the ‘open’ and ‘closed’ conformations. In neither conformation does Thr513 contact the NADP+. Although mutagenesis of Thr513 did not significantly alter the substrate scope, changes in peroxyflavin stability and reaction rates were observed. Mutation of this position also brought about changes in the regio- and enantioselectivity of the enzyme. Moreover, lower rates of overoxidation during sulfoxidation of thioanisole were also observed.
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13
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Schmidt S, Bornscheuer UT. Baeyer-Villiger monooxygenases: From protein engineering to biocatalytic applications. FLAVIN-DEPENDENT ENZYMES: MECHANISMS, STRUCTURES AND APPLICATIONS 2020; 47:231-281. [DOI: 10.1016/bs.enz.2020.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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14
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Biochemical and structural insights into the cytochrome P450 reductase from Candida tropicalis. Sci Rep 2019; 9:20088. [PMID: 31882753 PMCID: PMC6934812 DOI: 10.1038/s41598-019-56516-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/04/2019] [Indexed: 12/15/2022] Open
Abstract
Cytochrome P450 reductases (CPRs) are diflavin oxidoreductases that supply electrons to type II cytochrome P450 monooxygenases (CYPs). In addition, it can also reduce other proteins and molecules, including cytochrome c, ferricyanide, and different drugs. Although various CPRs have been functionally and structurally characterized, the overall mechanism and its interaction with different redox acceptors remain elusive. One of the main problems regarding electron transfer between CPRs and CYPs is the so-called “uncoupling”, whereby NAD(P)H derived electrons are lost due to the reduced intermediates’ (FAD and FMN of CPR) interaction with molecular oxygen. Additionally, the decay of the iron-oxygen complex of the CYP can also contribute to loss of reducing equivalents during an unproductive reaction cycle. This phenomenon generates reactive oxygen species (ROS), leading to an inefficient reaction. Here, we present the study of the CPR from Candida tropicalis (CtCPR) lacking the hydrophobic N-terminal part (Δ2–22). The enzyme supports the reduction of cytochrome c and ferricyanide, with an estimated 30% uncoupling during the reactions with cytochrome c. The ROS produced was not influenced by different physicochemical conditions (ionic strength, pH, temperature). The X-ray structures of the enzyme were solved with and without its cofactor, NADPH. Both CtCPR structures exhibited the closed conformation. Comparison with the different solved structures revealed an intricate ionic network responsible for the regulation of the open/closed movement of CtCPR.
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15
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Ebrecht AC, van der Bergh N, Harrison STL, Smit MS, Sewell BT, Opperman DJ. Biochemical and structural insights into the cytochrome P450 reductase from Candida tropicalis. Sci Rep 2019; 9:20088. [PMID: 31882753 DOI: 10.1101/711317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/04/2019] [Indexed: 05/28/2023] Open
Abstract
Cytochrome P450 reductases (CPRs) are diflavin oxidoreductases that supply electrons to type II cytochrome P450 monooxygenases (CYPs). In addition, it can also reduce other proteins and molecules, including cytochrome c, ferricyanide, and different drugs. Although various CPRs have been functionally and structurally characterized, the overall mechanism and its interaction with different redox acceptors remain elusive. One of the main problems regarding electron transfer between CPRs and CYPs is the so-called "uncoupling", whereby NAD(P)H derived electrons are lost due to the reduced intermediates' (FAD and FMN of CPR) interaction with molecular oxygen. Additionally, the decay of the iron-oxygen complex of the CYP can also contribute to loss of reducing equivalents during an unproductive reaction cycle. This phenomenon generates reactive oxygen species (ROS), leading to an inefficient reaction. Here, we present the study of the CPR from Candida tropicalis (CtCPR) lacking the hydrophobic N-terminal part (Δ2-22). The enzyme supports the reduction of cytochrome c and ferricyanide, with an estimated 30% uncoupling during the reactions with cytochrome c. The ROS produced was not influenced by different physicochemical conditions (ionic strength, pH, temperature). The X-ray structures of the enzyme were solved with and without its cofactor, NADPH. Both CtCPR structures exhibited the closed conformation. Comparison with the different solved structures revealed an intricate ionic network responsible for the regulation of the open/closed movement of CtCPR.
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Affiliation(s)
- Ana C Ebrecht
- Department of Microbial, Biochemical, and Food Biotechnology, University of the Free State, Bloemfontein, 9301, South Africa
- South African DST-NRF Centre of Excellence in Catalysis (c*Change), University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Naadia van der Bergh
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
- South African DST-NRF Centre of Excellence in Catalysis (c*Change), University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Susan T L Harrison
- Centre for Bioprocess Engineering Research (CeBER), Department of Chemical Engineering, University of Cape Town, Rondebosch, Cape Town, 7701, South Africa
- South African DST-NRF Centre of Excellence in Catalysis (c*Change), University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - Martha S Smit
- Department of Microbial, Biochemical, and Food Biotechnology, University of the Free State, Bloemfontein, 9301, South Africa
- South African DST-NRF Centre of Excellence in Catalysis (c*Change), University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa
| | - B Trevor Sewell
- Structural Biology Research Unit, Department of Integrative Biomedical Sciences, Institute for Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, 7700, South Africa.
| | - Diederik J Opperman
- Department of Microbial, Biochemical, and Food Biotechnology, University of the Free State, Bloemfontein, 9301, South Africa.
- South African DST-NRF Centre of Excellence in Catalysis (c*Change), University of Cape Town, Private Bag, Rondebosch, Cape Town, 7701, South Africa.
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Fürst MJLJ, Gran-Scheuch A, Aalbers FS, Fraaije MW. Baeyer–Villiger Monooxygenases: Tunable Oxidative Biocatalysts. ACS Catal 2019. [DOI: 10.1021/acscatal.9b03396] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Maximilian J. L. J. Fürst
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, Groningen 9747AG, The Netherlands
| | - Alejandro Gran-Scheuch
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, Groningen 9747AG, The Netherlands
- Department of Chemical and Bioprocesses Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna 4860, Santiago 7820436, Chile
| | - Friso S. Aalbers
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, Groningen 9747AG, The Netherlands
| | - Marco W. Fraaije
- Molecular Enzymology Group, University of Groningen, Nijenborgh 4, Groningen 9747AG, The Netherlands
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Efficient Synthesis of Methyl 3-Acetoxypropionate by a Newly Identified Baeyer-Villiger Monooxygenase. Appl Environ Microbiol 2019; 85:AEM.00239-19. [PMID: 30926727 DOI: 10.1128/aem.00239-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 03/24/2019] [Indexed: 11/20/2022] Open
Abstract
Baeyer-Villiger monooxygenases (BVMOs) are an emerging class of promising biocatalysts for the oxidation of ketones to prepare corresponding esters or lactones. Although many BVMOs have been reported, the development of highly efficient enzymes for use in industrial applications is desirable. In this work, we identified a BVMO from Rhodococcus pyridinivorans (BVMORp) with a high affinity toward aliphatic methyl ketones (Km < 3.0 μM). The enzyme was highly soluble and relatively stable, with a half-life of 23 h at 30°C and pH 7.5. The most effective substrate discovered so far is 2-hexanone (k cat = 2.1 s-1; Km = 1.5 μM). Furthermore, BVMORp exhibited excellent regioselectivity toward most aliphatic ketones, preferentially forming typical (i.e., normal) products. Using the newly identified BVMORp as the catalyst, a high concentration (26.0 g/liter; 200 mM) of methyl levulinate was completely converted to methyl 3-acetoxypropionate after 4 h, with a space-time yield of 5.4 g liter-1 h-1 Thus, BVMORp is a promising biocatalyst for the synthesis of 3-hydroxypropionate from readily available biobased levulinate to replace the conventional fermentation.IMPORTANCE BVMOs are emerging as a green alternative to traditional oxidants in the BV oxidation of ketones. Although many BVMOs are discovered and used in organic synthesis, few are really applied in industry, especially in the case of aliphatic ketones. Herein, a highly soluble and relatively stable monooxygenase from Rhodococcus pyridinivorans (BVMORp) was identified with high activity and excellent regioselectivity toward most aliphatic ketones. BVMORp possesses unusually high substrate loading during the catalysis of the oxidation of biobased methyl levulinate to 3-hydroxypropionic acid derivatives. This study indicates that the synthesis of 3-hydroxypropionate from readily available biobased levulinate by BVMORp-catalyzed oxidation holds great promise to replace traditional fermentation.
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Tolmie C, Smit MS, Opperman DJ. Native roles of Baeyer–Villiger monooxygenases in the microbial metabolism of natural compounds. Nat Prod Rep 2019; 36:326-353. [DOI: 10.1039/c8np00054a] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Baeyer–Villiger monooxygenases function in the primary metabolism of atypical carbon sources, as well as the synthesis of complex microbial metabolites.
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Affiliation(s)
- Carmien Tolmie
- Department of Biotechnology
- University of the Free State
- Bloemfontein
- South Africa
| | - Martha S. Smit
- Department of Biotechnology
- University of the Free State
- Bloemfontein
- South Africa
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Chevalier Y, Lock Toy Ki Y, le Nouen D, Mahy JP, Goddard JP, Avenier F. Aerobic Baeyer-Villiger Oxidation Catalyzed by a Flavin-Containing Enzyme Mimic in Water. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yoan Chevalier
- Univ Paris Sud; Université Paris Saclay; LCBB, ICMMO, UMR CNRS 8182; 91405 Orsay France
| | - Yvette Lock Toy Ki
- Université de Haute-Alsace; Université de Strasbourg; CNRS, LIMA UMR 7042; 68100 Mulhouse France
| | - Didier le Nouen
- Université de Haute-Alsace; Université de Strasbourg; CNRS, LIMA UMR 7042; 68100 Mulhouse France
| | - Jean-Pierre Mahy
- Univ Paris Sud; Université Paris Saclay; LCBB, ICMMO, UMR CNRS 8182; 91405 Orsay France
| | - Jean-Philippe Goddard
- Université de Haute-Alsace; Université de Strasbourg; CNRS, LIMA UMR 7042; 68100 Mulhouse France
| | - Frédéric Avenier
- Univ Paris Sud; Université Paris Saclay; LCBB, ICMMO, UMR CNRS 8182; 91405 Orsay France
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Chevalier Y, Lock Toy Ki Y, le Nouen D, Mahy JP, Goddard JP, Avenier F. Aerobic Baeyer-Villiger Oxidation Catalyzed by a Flavin-Containing Enzyme Mimic in Water. Angew Chem Int Ed Engl 2018; 57:16412-16415. [PMID: 30358055 DOI: 10.1002/anie.201810124] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 10/11/2018] [Indexed: 01/16/2023]
Abstract
Direct incorporation of molecular oxygen into small organic molecules has attracted much attention for the development of new environmentally friendly oxidation processes. In line with this approach, bioinspired systems mimicking enzyme activities are of particular interest since they may perform catalysis in aqueous media. Demonstrated herein is the incorporation of a natural flavin cofactor (FMN) into the specific microenvironment of a water-soluble polymer which allows the efficient reduction of the FMN by NADH in aqueous solution. Once reduced, this artificial flavoenzyme can then activate molecular dioxygen under aerobic conditions and result in the Baeyer-Villiger reaction at room temperature in water.
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Affiliation(s)
- Yoan Chevalier
- Univ Paris Sud, Université Paris Saclay, LCBB, ICMMO, UMR CNRS 8182, 91405, Orsay, France
| | - Yvette Lock Toy Ki
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, 68100, Mulhouse, France
| | - Didier le Nouen
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, 68100, Mulhouse, France
| | - Jean-Pierre Mahy
- Univ Paris Sud, Université Paris Saclay, LCBB, ICMMO, UMR CNRS 8182, 91405, Orsay, France
| | - Jean-Philippe Goddard
- Université de Haute-Alsace, Université de Strasbourg, CNRS, LIMA UMR 7042, 68100, Mulhouse, France
| | - Frédéric Avenier
- Univ Paris Sud, Université Paris Saclay, LCBB, ICMMO, UMR CNRS 8182, 91405, Orsay, France
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Alternative Splicing of the Aflatoxin-Associated Baeyer⁻Villiger Monooxygenase from Aspergillus flavus: Characterisation of MoxY Isoforms. Toxins (Basel) 2018; 10:toxins10120521. [PMID: 30563144 PMCID: PMC6315744 DOI: 10.3390/toxins10120521] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/01/2018] [Accepted: 12/03/2018] [Indexed: 01/24/2023] Open
Abstract
Aflatoxins are carcinogenic mycotoxins that are produced by the filamentous fungus Aspergillus flavus, a contaminant of numerous food crops. Aflatoxins are synthesised via the aflatoxin biosynthesis pathway, with the enzymes involved encoded by the aflatoxin biosynthesis gene cluster. MoxY is a type I Baeyer–Villiger monooxygenase (BVMO), responsible for the conversion of hydroxyversicolorone (HVN) and versicolorone (VN) to versiconal hemiacetal acetate (VHA) and versiconol acetate (VOAc), respectively. Using mRNA data, an intron near the C-terminus was identified that is alternatively spliced, creating two possible MoxY isoforms which exist in vivo, while analysis of the genomic DNA suggests an alternative start codon leading to possible elongation of the N-terminus. These four variants of the moxY gene were recombinantly expressed in Escherichia coli, and their activity evaluated with respect to their natural substrates HVN and VN, as well as surrogate ketone substrates. Activity of the enzyme is absolutely dependent on the additional 22 amino acid residues at the N-terminus. Two MoxY isoforms with alternative C-termini, MoxYAltN and MoxYAltNC, converted HVN and VN, in addition to a range of ketone substrates. Stability and flavin-binding data suggest that MoxYAltN is, most likely, the dominant isoform. MoxYAltNC is generated by intron splicing, in contrast to intron retention, which is the most prevalent type of alternative splicing in ascomycetes. The alternative C-termini did not alter the substrate acceptance profile, or regio- or enantioselectivity of the enzyme, but did significantly affect the solubility and stability.
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Improving catalytic activity of the Baeyer-Villiger monooxygenase-based Escherichia coli biocatalysts for the overproduction of (Z)-11-(heptanoyloxy)undec-9-enoic acid from ricinoleic acid. Sci Rep 2018; 8:10280. [PMID: 29980730 PMCID: PMC6035261 DOI: 10.1038/s41598-018-28575-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 06/21/2018] [Indexed: 12/21/2022] Open
Abstract
Baeyer–Villiger monooxygenases (BVMOs) can be used for the biosynthesis of lactones and esters from ketones. However, the BVMO-based biocatalysts are not so stable under process conditions. Thereby, this study focused on enhancing stability of the BVMO-based biocatalysts. The biotransformation of ricinoleic acid into (Z)-11-(heptanoyloxy)undec-9-enoic acid by the recombinant Escherichia coli expressing the BVMO from Pseudomonas putida and an alcohol dehydrogenase from Micrococcus luteus was used as a model system. After thorough investigation of the key factors to influence stability of the BVMO, Cys302 was identified as an engineering target. The substitution of Cys302 to Leu enabled the engineered enzyme (i.e., E6BVMOC302L) to become more stable toward oxidative and thermal stresses. The catalytic activity of E6BVMOC302L-based E. coli biocatalysts was also greater than the E6BVMO-based biocatalysts. Another factor to influence biocatalytic performance of the BVMO-based whole-cell biocatalysts was availability of carbon and energy source during biotransformations. Glucose feeding into the reaction medium led to a marked increase of final product concentrations. Overall, the bioprocess engineering to improve metabolic stability of host cells in addition to the BVMO engineering allowed us to produce (Z)-11-(heptanoyloxy)undec-9-enoic acid to a concentration of 132 mM (41 g/L) from 150 mM ricinoleic acid within 8 h.
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Discovery of Two Native Baeyer-Villiger Monooxygenases for Asymmetric Synthesis of Bulky Chiral Sulfoxides. Appl Environ Microbiol 2018; 84:AEM.00638-18. [PMID: 29752270 DOI: 10.1128/aem.00638-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 05/07/2018] [Indexed: 01/25/2023] Open
Abstract
Two Baeyer-Villiger monooxygenases (BVMOs), designated BoBVMO and AmBVMO, were discovered from Bradyrhizobium oligotrophicum and Aeromicrobium marinum, respectively. Both monooxygenases displayed novel features for catalyzing the asymmetric sulfoxidation of bulky and pharmaceutically relevant thioethers. Evolutionary relationship and sequence analysis revealed that the two BVMOs belong to the family of typical type I BVMOs and the subtype ethionamide monooxygenase. Both BVMOs are active toward medium- and long-chain aliphatic ketones as well as various thioether substrates but are ineffective toward cyclohexanone, aromatic ketones, and other typical BVMO substrates. BoBVMO and AmBVMO showed the highest activities (0.117 and 0.025 U/mg protein, respectively) toward thioanisole among the tested substrates. Furthermore, these BVMOs exhibited distinct activity and excellent stereoselectivity toward bulky and prochiral prazole thioethers, which is a unique feature of this family of BVMOs. No native enzyme has been reported for the asymmetric sulfoxidation of bulky prazole thioethers into chiral sulfoxides. The identification of BoBVMO and AmBVMO provides an important scaffold for discovering enzymes capable of asymmetrically oxidizing bulky thioether substrates by genome mining.IMPORTANCE Baeyer-Villiger monooxygenases (BVMOs) are valuable enzyme catalysts that are an alternative to the chemical Baeyer-Villiger oxidation reaction. Although BVMOs display broad substrate ranges, no native enzymes were reported to have activity toward the asymmetric oxidation of bulky prazole-like thioether substrates. Herein, we report the discovery of two type I BVMOs from Bradyrhizobium oligotrophicum (BoBVMO) and Aeromicrobium marinum (AmBVMO) which are able to catalyze the asymmetric sulfoxidation of bulky prazole thioethers (proton pump inhibitors [PPIs], a group of drugs whose main action is a pronounced and long-lasting reduction of gastric acid production). Efficient catalysis of omeprazole oxidation by BoBVMO was developed, indicating that this enzyme is a promising biocatalyst for the synthesis of bulky and pharmaceutically relevant chiral sulfoxide drugs. These results demonstrate that the newly identified enzymes are suitable templates for the discovery of more and better thioether-converting BVMOs.
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Kubitza C, Faust A, Gutt M, Gäth L, Ober D, Scheidig AJ. Crystal structure of pyrrolizidine alkaloid N-oxygenase from the grasshopper Zonocerus variegatus. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:422-432. [PMID: 29717713 DOI: 10.1107/s2059798318003510] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 02/28/2018] [Indexed: 11/10/2022]
Abstract
The high-resolution crystal structure of the flavin-dependent monooxygenase (FMO) from the African locust Zonocerus variegatus is presented and the kinetics of structure-based protein variants are discussed. Z. variegatus expresses three flavin-dependent monooxygenase (ZvFMO) isoforms which contribute to a counterstrategy against pyrrolizidine alkaloids (PAs). PAs are protoxic compounds produced by some angiosperm lineages as a chemical defence against herbivores. N-Oxygenation of PAs and the accumulation of PA N-oxides within their haemolymph result in two evolutionary advantages for these insects: (i) they circumvent the defence mechanism of their food plants and (ii) they can use PA N-oxides to protect themselves against predators, which cannot cope with the toxic PAs. Despite a high degree of sequence identity and a similar substrate spectrum, the three ZvFMO isoforms differ greatly in enzyme activity. Here, the crystal structure of the Z. variegatus PA N-oxygenase (ZvPNO), the most active ZvFMO isoform, is reported at 1.6 Å resolution together with kinetic studies of a second isoform, ZvFMOa. This is the first available crystal structure of an FMO from class B (of six different FMO subclasses, A-F) within the family of flavin-dependent monooxygenases that originates from a more highly developed organism than yeast. Despite the differences in sequence between family members, their overall structure is very similar. This indicates the need for high conservation of the three-dimensional structure for this type of reaction throughout all kingdoms of life. Nevertheless, this structure provides the closest relative to the human enzyme that is currently available for modelling studies. Of note, the crystal structure of ZvPNO reveals a unique dimeric arrangement as well as small conformational changes within the active site that have not been observed before. A newly observed kink within helix α8 close to the substrate-binding path might indicate a potential mechanism for product release. The data show that even single amino-acid exchanges in the substrate-entry path, rather than the binding site, have a significant impact on the specific enzyme activity of the isoforms.
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Affiliation(s)
- Christian Kubitza
- Structural Biology, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Annette Faust
- Structural Biology, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Miriam Gutt
- Biochemical Ecology and Molecular Evolution, Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Luzia Gäth
- Structural Biology, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Dietrich Ober
- Biochemical Ecology and Molecular Evolution, Botanical Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
| | - Axel J Scheidig
- Structural Biology, Zoological Institute, Kiel University, Am Botanischen Garten 1-9, 24118 Kiel, Germany
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Affiliation(s)
- Yujie Liang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Jialiang Wei
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Xu Qiu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
| | - Ning Jiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Xue Yuan Road 38, Beijing 100191, China
- State Key Laboratory of Organometallic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
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Carvalho ATP, Dourado DFAR, Skvortsov T, de Abreu M, Ferguson LJ, Quinn DJ, Moody TS, Huang M. Spatial requirement for PAMO for transformation of non-native linear substrates. Phys Chem Chem Phys 2018; 20:2558-2570. [PMID: 29318252 DOI: 10.1039/c7cp07172h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phenylacetone monooxygenase is the most stable and thermo-tolerant member of the Baeyer-Villiger monooxygenases family, and therefore it is an ideal candidate for the synthesis of industrially relevant ester or lactone compounds. However, its limited substrate scope has largely limited its industrial applications. Linear substrates are interesting from an industrial point of view, it is thus necessary to identify the essential spatial requirement for achieving high conversions for non-native linear substrates. Here using molecular dynamics simulations, we compared the conversion of a non-native linear substrate 2-octanone and the native substrate phenylacetone, catalyzed by the WT enzyme and a quadruple variant P253F/G254A/R258M/L443F that exhibits significantly improved activity towards 2-octanone. We uncovered that a remarkable movement of L289 is crucial for a reshaping of the active site of the quadruple variant so as to prevent the aliphatic substrate from moving away from the C4a-peroxyflavin, thus enabling it to keep a catalytically relevant pose during the oxygenation process. By performing steady-state kinetic analysis of two single-mutation variants at position 258, we further validated that the L289 reposition is attributed to the combined effect of quadruple mutations. In order to further explore the substrate scope of PAMO we also studied the binding of cyclopentanone and 2-phenylcyclohexanone, which are the typical substrates of CPMO in group I and CHMO in group III, respectively. Our study provides fundamental atomic-level insights in rational engineering of PAMO for wide applications in industrial biocatalysis, in particular, in the biotransformation of long-chain aliphatic oils into potential biodiesels.
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Affiliation(s)
- Alexandra T P Carvalho
- School of Chemistry and Chemical Engineering, Queen's University, David Keir Building, Stranmillis Road, Belfast BT9 5AG, Northern Ireland, UK.
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Padhan D, Pattnaik S, Behera AK. Growth-arresting Activity of Acmella Essential Oil and its Isolated Component D-Limonene (1, 8 P-Mentha Diene) against Trichophyton rubrum (Microbial Type Culture Collection 296). Pharmacogn Mag 2017; 13:S555-S560. [PMID: 29142414 PMCID: PMC5669097 DOI: 10.4103/pm.pm_65_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 04/25/2017] [Indexed: 02/06/2023] Open
Abstract
Background: Spilanthes acmella is used as a remedy in toothache complaints by the tribal people of Western part of Odisha, India. Objective: The objective of this study was to study the growth-arresting activity of an indigenous Acmella essential oil (EO) (S. acmella Murr, Asteraceae) and its isolated component, d-limonene against Trichophyton rubrum (microbial type culture collection 296). Materials and Methods: The EO was extracted from flowers of indigenous S. acmella using Clevenger's apparatus and analyzed by gas chromatography–mass spectrometry (GC-MS). High pressure liquid chromatography (HPLC) was carried out to isolate the major constituent. The isolated fraction was subjected to fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The antidermatophytic activity was screened for using “disc diffusion” and “slant dilution” method followed by optical, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies. The molecular dockings were made between d-limonene with cell wall synthesis-related key enzymes (14 methyl deaminase and monooxygenase). Results: The GC-MS analysis EO had inferred the presence of 7 number of major (≥2%) components. The component with highest peak area (%) was found to be 41.02. The HPLC-isolated fraction was identified as d-limonene (1,8 p-Mentha-diene) by FTIR and NMR. Qualitative and quantitative assays had suggested the growth inhibitory activity of Acmella EO and its component. Shrinkage, evacuation, cell wall puncture, and leakage of cellular constituents by the activity of Acmella oil and d-limonene were evidenced from optical, SEM, and TEM studies. The computer simulation had predicted the binding strengths of d-limonene and fluconazole with dermatophyte cell wall enzymes. Conclusion: There could have been synergistic action of all or some of compounds present in indigenous Acmella EO. SUMMARY There was presence of seven number of (d-limonene, ocimene, β-myrcene, cyclohexene, 3-(1, 5-dimethyl-4-hexenyl)-6-methylene, β-caryophyllene, and β-sesquiphellandrene and β-phellandrene) major components in the indigenous Acmella essential oil The d-limonene content was 41.02% in the indigenous oil The antidermatophytic activity of Acmella essential oil could have been attributable to its chemotypes.
Abbreviations used: °C: Degree centigrade; w/v: Weight/volume; TS: Transverse section; min: minute; Hz: hertz: h: Hr.
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Affiliation(s)
- Diptikanta Padhan
- Laboratory of Medical Microbiology, School of Life Sciences, Sambalpur University, Sambalpur, Odisha, India
| | - Smaranika Pattnaik
- Laboratory of Medical Microbiology, School of Life Sciences, Sambalpur University, Sambalpur, Odisha, India
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Mthethwa KS, Kassier K, Engel J, Kara S, Smit MS, Opperman DJ. Fungal BVMOs as alternatives to cyclohexanone monooxygenase. Enzyme Microb Technol 2017; 106:11-17. [PMID: 28859804 DOI: 10.1016/j.enzmictec.2017.06.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/19/2017] [Accepted: 06/30/2017] [Indexed: 12/12/2022]
Abstract
FAD-dependent Baeyer-Villiger monooxygenases (BVMOs) have proven to be useful biocatalysts in the selective and specific oxygenation of various ketones. Despite the cloning, heterologous expression and characterization of close to 80 members of this enzyme family, some sub-groups of BVMOs still remain underrepresented and their evolutionary relationship uncertain. Until recently, very few fungal BVMOs have been described. Our previous investigations into BVMOs from the fungus Aspergillus flavus, yielded very little activity on simple cyclic ketones. Here we report on another four BVMOs from A. flavus that are more closely related to cyclohexanone monooxygenase (CHMO) from Acinetobacter sp. NCIMB 9871. Evolutionary analysis with other characterized BVMOs show their closest relationship to be with either cycloalkanone monooxygenase (CAMO) or 2-oxo-Δ3-4,5,5-trimethylcyclopentenylacetyl-coenzyme A monooxygenase (OTEMO). The OTEMO-related BVMOAFL706 and BVMOAFL334 were heterologously expressed in E. coli, purified and shown to be able to convert a range of cyclic and substituted cyclic ketones. Of the unsubstituted cyclic ketones, cyclohexanone showed the highest conversion with maximum turnover frequencies reaching 4.3s-1 for BVMOAFL706. Unlike CHMOacinet, and many of the closely related BVMOs, no substrate inhibition was observed with cyclohexanone to a concentration of up to 30mM, creating the possibility for applications requiring high substrate loading. Aliphatic ketones were also readily converted with excellent regioselectivity. Similar to CHMOacinet, acetophenones were not converted and the oxidation of rac-cis-bicyclo[3.2.0]hept-2-en-6-one occurs enantiodivergently, with the (1R,5S) isomer converted to the "normal" lactone and the (1S,5R) isomer to the "abnormal" lactone.
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Affiliation(s)
- Katlego Siphamandla Mthethwa
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
| | - Karin Kassier
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
| | - Jennifer Engel
- Institute of Technical Biocatalysis, Hamburg University of Technology, Denickestr. 15, Hamburg, 21073, Germany
| | - Selin Kara
- Institute of Technical Biocatalysis, Hamburg University of Technology, Denickestr. 15, Hamburg, 21073, Germany
| | - Martha Sophia Smit
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa
| | - Diederik Johannes Opperman
- Department of Biotechnology, University of the Free State, 205 Nelson Mandela Drive, Bloemfontein, 9300, South Africa.
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29
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Panek A, Świzdor A, Milecka-Tronina N, Panek JJ. Insight into the orientational versatility of steroid substrates-a docking and molecular dynamics study of a steroid receptor and steroid monooxygenase. J Mol Model 2017; 23:96. [PMID: 28251412 PMCID: PMC5332494 DOI: 10.1007/s00894-017-3278-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 02/13/2017] [Indexed: 12/11/2022]
Abstract
Numerous steroids are essential plant, animal, and human hormones. The medical and industrial applications of these hormones require the identification of new synthetic routes, including biotransformations. The metabolic fate of a steroid can be complicated; it may be transformed into a variety of substituted derivatives. This may be because a steroid molecule can adopt several possible orientations in the binding pocket of a receptor or an enzyme. The present study, based on docking and molecular dynamics, shows that it is indeed possible for a steroid molecule to bind to a receptor binding site in two or more orientations (normal, head-to-tail reversed, upside down). Three steroids were considered: progesterone, dehydroepiandrosterone, and 7-oxo-dehydroepiandrosterone. Two proteins were employed as hosts: the human mineralocorticoid receptor and a bacterial Baeyer-Villiger monooxygenase. When the steroids were in nonstandard orientations, the estimated binding strength was found to be only moderately diminished and the network of hydrogen bonds between the steroid and the host was preserved.
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Affiliation(s)
- Anna Panek
- Department of Chemistry, Wrocław University of Environmental and Life Sciences, C. K. Norwida 25, 50-375, Wrocław, Poland
| | - Alina Świzdor
- Department of Chemistry, Wrocław University of Environmental and Life Sciences, C. K. Norwida 25, 50-375, Wrocław, Poland
| | - Natalia Milecka-Tronina
- Department of Chemistry, Wrocław University of Environmental and Life Sciences, C. K. Norwida 25, 50-375, Wrocław, Poland
| | - Jarosław J Panek
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383, Wrocław, Poland.
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30
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Ferroni FM, Tolmie C, Smit MS, Opperman DJ. Alkyl Formate Ester Synthesis by a Fungal Baeyer-Villiger Monooxygenase. Chembiochem 2017; 18:515-517. [DOI: 10.1002/cbic.201600684] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Felix Martin Ferroni
- Department of Biotechnology; University of the Free State; 205 Nelson Mandela Drive Bloemfontein 9300 South Africa
| | - Carmien Tolmie
- Department of Biotechnology; University of the Free State; 205 Nelson Mandela Drive Bloemfontein 9300 South Africa
| | - Martha Sophia Smit
- Department of Biotechnology; University of the Free State; 205 Nelson Mandela Drive Bloemfontein 9300 South Africa
| | - Diederik Johannes Opperman
- Department of Biotechnology; University of the Free State; 205 Nelson Mandela Drive Bloemfontein 9300 South Africa
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31
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Li G, Fürst MJLJ, Mansouri HR, Ressmann AK, Ilie A, Rudroff F, Mihovilovic MD, Fraaije MW, Reetz MT. Manipulating the stereoselectivity of the thermostable Baeyer–Villiger monooxygenase TmCHMO by directed evolution. Org Biomol Chem 2017; 15:9824-9829. [DOI: 10.1039/c7ob02692g] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The thermostable Baeyer–Villiger monooxygenase TmCHMO and evolved mutants are viable catalysts in stereoselective reactions of structurally different ketones.
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Affiliation(s)
- Guangyue Li
- Max-Planck-Institut für Kohlenforschung
- Mülheim an der Ruhr
- Germany
- Fachbereich Chemie
- Philipps-Universität
| | | | | | - Anna K. Ressmann
- Institute of Applied Synthetic Chemistry
- TU Wien
- 1060 Vienna
- Austria
| | - Adriana Ilie
- Max-Planck-Institut für Kohlenforschung
- Mülheim an der Ruhr
- Germany
- Fachbereich Chemie
- Philipps-Universität
| | - Florian Rudroff
- Institute of Applied Synthetic Chemistry
- TU Wien
- 1060 Vienna
- Austria
| | | | - Marco W. Fraaije
- Molecular Enzymology Group
- University of Groningen
- 9747 AG Groningen
- The Netherlands
| | - Manfred T. Reetz
- Max-Planck-Institut für Kohlenforschung
- Mülheim an der Ruhr
- Germany
- Fachbereich Chemie
- Philipps-Universität
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