1
|
Tian J, Zhou S, Chen Y, Zhao Y, Li S, Yang P, Xu X, Chen Y, Cheng X, Yang J. Synthesis of Chiral Sulfoxides by A Cyclic Oxidation-Reduction Multi-Enzymatic Cascade Biocatalysis. Chemistry 2024; 30:e202304081. [PMID: 38288909 DOI: 10.1002/chem.202304081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Indexed: 02/16/2024]
Abstract
Optically pure sulfoxides are valuable organosulfur compounds extensively employed in medicinal and organic synthesis. In this study, we present a biocatalytic oxidation-reduction cascade system designed for the preparation of enantiopure sulfoxides. The system involves the cooperation of a low-enantioselective chimeric oxidase SMO (styrene monooxygenase) with a high-enantioselective reductase MsrA (methionine sulfoxide reductase A), facilitating "non-selective oxidation and selective reduction" cycles for prochiral sulfide oxidation. The regeneration of requisite cofactors for MsrA and SMO was achieved via a cascade catalysis process involving three auxiliary enzymes, sustained by cost-effective D-glucose. Under the optimal reaction conditions, a series of heteroaryl alkyl, aryl alkyl and dialkyl sulfoxides in R configuration were synthesized through this "one-pot, one step" cascade reaction. The obtained compounds exhibited high yields of >90 % and demonstrated enantiomeric excess (ee) values exceeding 90 %. This study represents an unconventional and efficient biocatalytic way in utilizing the low-enantioselective oxidase for the synthesis of enantiopure sulfoxides.
Collapse
Affiliation(s)
- Jin Tian
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Shihuan Zhou
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Yanli Chen
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Yuyan Zhao
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Song Li
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Piao Yang
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Xianlin Xu
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Yongzheng Chen
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Xiaoling Cheng
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| | - Jiawei Yang
- Department of Biochemistry, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
- Key Laboratory of Biocatalysis & Chiral Drug Synthesis of Guizhou Province, Zunyi Medical University, No.6 West Xuefu Road, Xinpu District, Zunyi City, Guizhou Province, P. R. China
| |
Collapse
|
2
|
Knaus T, Macheroux P, Mutti FG. Fus-SMO: Kinetics, Biochemical Characterisation and In Silico Modelling of a Chimeric Styrene Monooxygenase Demonstrating Quantitative Coupling Efficiency. Chembiochem 2024; 25:e202300833. [PMID: 38306174 DOI: 10.1002/cbic.202300833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/31/2024] [Accepted: 02/01/2024] [Indexed: 02/03/2024]
Abstract
The styrene monooxygenase, a two-component enzymatic system for styrene epoxidation, was characterised through the study of Fus-SMO - a chimera resulting from the fusion of StyA and StyB using a flexible linker. Notably, it remains debated whether the transfer of FADH2 from StyB to StyA occurs through diffusion, channeling, or a combination of both. Fus-SMO was identified as a trimer with one bound FAD molecule. In silico modelling revealed a well-distanced arrangement (45-50 Å) facilitated by the flexible linker's loopy structure. Pre-steady-state kinetics elucidated the FADox reduction intricacies (kred=110 s-1 for bound FADox), identifying free FADox binding as the rate-determining step. The aerobic oxidation of FADH2 (kox=90 s-1) and subsequent decomposition to FADox and H2O2 demonstrated StyA's protective effect on the bound hydroperoxoflavin (kdec=0.2 s-1) compared to free cofactor (kdec=1.8 s-1). At varied styrene concentrations, kox for FADH2 ranged from 80 to 120 s-1. Studies on NADH consumption vs. styrene epoxidation revealed Fus-SMO's ability to achieve quantitative coupling efficiency in solution, surpassing natural two-component SMOs. The results suggest that Fus-SMO exhibits enhanced FADH2 channelling between subunits. This work contributes to comprehending FADH2 transfer mechanisms in SMO and illustrates how protein fusion can elevate catalytic efficiency for biocatalytic applications.
Collapse
Affiliation(s)
- Tanja Knaus
- Van 't Hoff Institute for Molecular Sciences, HIMS-Biocat, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Peter Macheroux
- Institute of Biochemistry, Graz University of Technology, Petersgasse 12, 8010, Graz, Austria
| | - Francesco G Mutti
- Van 't Hoff Institute for Molecular Sciences, HIMS-Biocat, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| |
Collapse
|
3
|
Bhanot V, Pali S, Panwar J. Understanding the in silico aspects of bacterial catabolic cascade for styrene degradation. Proteins 2023; 91:532-541. [PMID: 36416087 DOI: 10.1002/prot.26447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/31/2022] [Accepted: 11/15/2022] [Indexed: 11/24/2022]
Abstract
Styrene is a nonpolar organic compound used in very high volume for the industrial scale production of commercially important polymers such as polystyrene resins as well as copolymers like acrylonitrile butadiene styrene, latex, and rubber. These resins are widely used in the manufacturing of various products including single-use plastics such as disposable cups and containers, protective packaging, heat insulation, and so forth. The large-scale utilization leads to the over-accumulation of styrene waste in the environment causing deleterious health risks including cancer, neurological impairment, dysbiosis of central nervous system, and respiratory problems. To eliminate the accumulating waste. Microbial enzyme-based system represents the most environmental friendly and sustainable approach for elimination of styrene waste. However, comprehensive understanding of the enzyme-substrate interaction and associated pathways would be crucial for developing large-scale disposal systems. This study aims to understand the molecular interaction between the protein-ligand complexes of the styrene catabolic reactions by bacterial enzymes of sty operon. Molecular docking analysis for catalytic enzymes namely, styrene monooxygenase (SMO), styrene oxide isomerase (SOI), and phenylacetaldehyde dehydrogenase (PAD) of the bacterial sty operon was carried out with their individual substrates, that is, styrene, styrene oxide, and phenylacetic acid, respectively. The binding energy, amino acids forming binding cavity, and binding interactions between the protein-ligand binding sites were calculated for each case. The obtained binding energies showed a stable association of these complexes indicating the future scope of their utilization for large-scale bioremediation of styrene, and its commercially used polymers and copolymers.
Collapse
Affiliation(s)
- Vishalakshi Bhanot
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Snigdha Pali
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| | - Jitendra Panwar
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani, Rajasthan, India
| |
Collapse
|
4
|
Abstract
Tyrosol is an aromatic compound with great value that is widely used in the food and pharmaceutical industry. In this study, we reported a synthetic pathway for converting p-coumaric acid (p-CA) into tyrosol in Escherichia coli. We found that the enzyme cascade comprising ferulic acid decarboxylase (FDC1) from Saccharomyces cerevisiae, styrene monooxygenase (SMO), styrene oxide isomerase (SOI) from Pseudomonas putida, and phenylacetaldehyde reductase (PAR) from Solanum lycopersicum could efficiently synthesize tyrosol from p-CA with a conversion rate over 90%. To further expand the range of substrates, we also introduced tyrosine ammonia-lyase (TAL) from Flavobacterium johnsoniae to connect the synthetic pathway with the endogenous l-tyrosine metabolism. We found that tyrosol could be efficiently produced from glycerol, reaching 545.51 mg/L tyrosol in a tyrosine-overproducing strain under shake flasks. In summary, we have established alternative routes for tyrosol synthesis from p-CA (a potential lignin-derived biomass), glucose, and glycerol.
Collapse
Affiliation(s)
- Yumeng Lai
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Haofeng Chen
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Lingrui Liu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Bixia Fu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Peiling Wu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Wanrong Li
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Junyan Hu
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| | - Jifeng Yuan
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Fujian, 361102, China
| |
Collapse
|
5
|
Gyuranová D, Štadániová R, Hegyi Z, Fischer R, Rebroš M. Production of Enantiopure Chiral Epoxides with E. coli Expressing Styrene Monooxygenase. Molecules 2021; 26:1514. [PMID: 33802034 DOI: 10.3390/molecules26061514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/05/2021] [Accepted: 03/07/2021] [Indexed: 11/21/2022] Open
Abstract
Styrene monooxygenases are a group of highly selective enzymes able to catalyse the epoxidation of alkenes to corresponding chiral epoxides in excellent enantiopurity. Chiral compounds containing oxirane ring or products of their hydrolysis represent key building blocks and precursors in organic synthesis in the pharmaceutical industry, and many of them are produced on an industrial scale. Two-component recombinant styrene monooxygenase (SMO) from Marinobacterium litorale was expressed as a fused protein (StyAL2StyB) in Escherichia coli BL21(DE3). By high cell density fermentation, 35 gDCW/L of biomass with overexpressed SMO was produced. SMO exhibited excellent stability, broad substrate specificity, and enantioselectivity, as it remained active for months and converted a group of alkenes to corresponding chiral epoxides in high enantiomeric excess (˃95–99% ee). Optically pure (S)-4-chlorostyrene oxide, (S)-allylbenzene oxide, (2R,5R)-1,2:5,6-diepoxyhexane, 2-(3-bromopropyl)oxirane, and (S)-4-(oxiran-2-yl)butan-1-ol were prepared by whole-cell SMO.
Collapse
|
6
|
Heine T, Großmann C, Hofmann S, Tischler D. Indigoid dyes by group E monooxygenases: mechanism and biocatalysis. Biol Chem 2020; 400:939-950. [PMID: 30844759 DOI: 10.1515/hsz-2019-0109] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 02/19/2019] [Indexed: 11/15/2022]
Abstract
Since ancient times, people have been attracted by dyes and they were a symbol of power. Some of the oldest dyes are indigo and its derivative Tyrian purple, which were extracted from plants and snails, respectively. These 'indigoid dyes' were and still are used for coloration of textiles and as a food additive. Traditional Chinese medicine also knows indigoid dyes as pharmacologically active compounds and several studies support their effects. Further, they are interesting for future technologies like organic electronics. In these cases, especially the indigo derivatives are of interest but unfortunately hardly accessible by chemical synthesis. In recent decades, more and more enzymes have been discovered that are able to produce these indigoid dyes and therefore have gained attention from the scientific community. In this study, group E monooxygenases (styrene monooxygenase and indole monooxygenase) were used for the selective oxygenation of indole (derivatives). It was possible for the first time to show that the product of the enzymatic reaction is an epoxide. Further, we synthesized and extracted indigoid dyes and could show that there is only minor by-product formation (e.g. indirubin or isoindigo). Thus, group E monooxygenase can be an alternative biocatalyst for the biosynthesis of indigoid dyes.
Collapse
Affiliation(s)
- Thomas Heine
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, D-09599 Freiberg, Germany
| | - Carolin Großmann
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, D-09599 Freiberg, Germany
| | - Sarah Hofmann
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, D-09599 Freiberg, Germany
| | - Dirk Tischler
- Institute of Biosciences, Environmental Microbiology, TU Bergakademie Freiberg, Leipziger Str. 29, D-09599 Freiberg, Germany.,Microbial Biotechnology, Ruhr University Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| |
Collapse
|
7
|
Abstract
Due to oil depletion and global climate change, sustainable manufacturing of fine chemicals from renewable feedstocks has gained increasing attention in the scientific community. In the present study, we attempted to engineer Saccharomyces cerevisiae toward de novo synthesis of (S)- or (R)-phenylethanediol, an important pharmaceutical intermediate. More specifically, the biocatalytic cascades contain the following: l-phenylalanine undergoes deamination/decarboxylation to styrene by using phenylalanine ammonia lyase (PAL) and ferulic acid decarboxylase (FDC), followed by S-selective epoxidation of styrene to give (S)-styrene oxide with styrene monooxygenase (SMO); regioselective hydrolysis of (S)-styrene oxide with epoxide hydrolase from Sphingomonas HXN-200 (SpEH) or from potato (StEH) gives rise to (S)- or (R)-phenylethanediol. In this work, we found that the artificial enzyme cascades could be functionally expressed in the heterologous host of S. cerevisiae. Small-scale shake flask studies revealed that the engineered yeast cell factories produced approximately 100-120 mg/L of (S)- or (R)-phenylethanediol after 96 h cultivation. To the best of our knowledge, this is the first attempt to explore an artificial route with styrene as an intermediate for producing phenylethanediol in S. cerevisiae. We envision that our engineering strategy will open a new research field for synthesizing other vicinal diol derived chemicals in yeast.
Collapse
Affiliation(s)
- Jifeng Yuan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
| | - Benedict Ryan Lukito
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
| | - Zhi Li
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 Singapore
| |
Collapse
|
8
|
Heine T, Zimmerling J, Ballmann A, Kleeberg SB, Rückert C, Busche T, Winkler A, Kalinowski J, Poetsch A, Scholtissek A, Oelschlägel M, Schmidt G, Tischler D. On the Enigma of Glutathione-Dependent Styrene Degradation in Gordonia rubripertincta CWB2. Appl Environ Microbiol 2018; 84:e00154-18. [PMID: 29475871 PMCID: PMC5930330 DOI: 10.1128/aem.00154-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 02/19/2018] [Indexed: 02/05/2023] Open
Abstract
Among bacteria, only a single styrene-specific degradation pathway has been reported so far. It comprises the activity of styrene monooxygenase, styrene oxide isomerase, and phenylacetaldehyde dehydrogenase, yielding phenylacetic acid as the central metabolite. The alternative route comprises ring-hydroxylating enzymes and yields vinyl catechol as central metabolite, which undergoes meta-cleavage. This was reported to be unspecific and also allows the degradation of benzene derivatives. However, some bacteria had been described to degrade styrene but do not employ one of those routes or only parts of them. Here, we describe a novel "hybrid" degradation pathway for styrene located on a plasmid of foreign origin. As putatively also unspecific, it allows metabolizing chemically analogous compounds (e.g., halogenated and/or alkylated styrene derivatives). Gordonia rubripertincta CWB2 was isolated with styrene as the sole source of carbon and energy. It employs an assembled route of the styrene side-chain degradation and isoprene degradation pathways that also funnels into phenylacetic acid as the central metabolite. Metabolites, enzyme activity, genome, transcriptome, and proteome data reinforce this observation and allow us to understand this biotechnologically relevant pathway, which can be used for the production of ibuprofen.IMPORTANCE The degradation of xenobiotics by bacteria is not only important for bioremediation but also because the involved enzymes are potential catalysts in biotechnological applications. This study reveals a novel degradation pathway for the hazardous organic compound styrene in Gordonia rubripertincta CWB2. This study provides an impressive illustration of horizontal gene transfer, which enables novel metabolic capabilities. This study presents glutathione-dependent styrene metabolization in an (actino-)bacterium. Further, the genomic background of the ability of strain CWB2 to produce ibuprofen is demonstrated.
Collapse
Affiliation(s)
- Thomas Heine
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Anne Ballmann
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Christian Rückert
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Tobias Busche
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Anika Winkler
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Jörn Kalinowski
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Ansgar Poetsch
- Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
- School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, United Kingdom
| | - Anika Scholtissek
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Gert Schmidt
- Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Tischler
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
- Microbial Biotechnology, Ruhr University Bochum, Bochum, Germany
| |
Collapse
|
9
|
Toda H, Itoh N. Development of a Novel Escherichia coli-Kocuria Shuttle Vector Using the Cryptic pKPAL3 Plasmid from K. palustris IPUFS-1 and Its Utilization in Producing Enantiopure ( S)-Styrene Oxide. Front Microbiol 2017; 8:2313. [PMID: 29230202 PMCID: PMC5711781 DOI: 10.3389/fmicb.2017.02313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 11/09/2017] [Indexed: 11/21/2022] Open
Abstract
The novel cryptic pKPAL3 plasmid was isolated from the Gram-positive microorganism Kocuria palustris IPUFS-1 and characterized in detail. pKPAL3 is a circular plasmid that is 4,443 bp in length. Open reading frame (ORF) and homology search analyses indicated that pKPAL3 possesses four ORFs; however, there were no replication protein coding genes predicted in the plasmid. Instead, there were two nucleotide sequence regions that showed significant identities with untranslated regions of K. rhizophila DC2201 (NBRC 103217) genomic sequences, and these sequences were essential for autonomous replication of pKPAL3 in Kocuria cells. Based on these findings, we constructed the novel Escherichia coli–Kocuria shuttle vectors pKITE301 (kanamycin resistant) and pKITE303 (thiostrepton resistant) from pKPAL3. The copy numbers of the constructed shuttle vectors were estimated to be 20 per cell, and they exhibited low segregation stability in Kocuria transformant cells in the absence of antibiotics. Moreover, constructed vectors showed compatibility with the other K. rhizophila shuttle vector pKITE103. We successfully expressed multiple heterologous genes, including the styrene monooxygenase gene from Rhodococcus sp. ST-10 (rhsmo) and alcohol dehydrogenase gene from Leifsonia sp. S749 (lsadh), in K. rhizophila DC2201 using the pKITE301P and pKITE103P vectors under the control of the glyceraldehyde 3-phosphate dehydrogenase (gapdh) promotor. The RhSMO–LSADH co-expressing K. rhizophila was used as a biocatalyst in an organic solvent–water biphasic reaction system to efficiently convert styrene into (S)-styrene oxide with 99% ee in the presence of 2-propanol as a hydrogen donor. The product concentration of the reaction in the organic solvent reached 235 mM after 30 h under optimum conditions. Thus, we demonstrated that this novel shuttle vector is useful for developing biocatalysts based on organic solvent-tolerant Kocuria cells.
Collapse
Affiliation(s)
- Hiroshi Toda
- Department of Biotechnology, Biotechnology Research Center, Toyama Prefectural University, Imizu, Japan
| | - Nobuya Itoh
- Department of Biotechnology, Biotechnology Research Center, Toyama Prefectural University, Imizu, Japan
| |
Collapse
|
10
|
Tischler D, Schlömann M, van Berkel WJH, Gassner GT. FAD C(4a)-hydroxide stabilized in a naturally fused styrene monooxygenase. FEBS Lett 2013; 587:3848-52. [PMID: 24157359 DOI: 10.1016/j.febslet.2013.10.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 10/26/2022]
Abstract
StyA2B represents a new class of styrene monooxygenases that integrates flavin-reductase and styrene-epoxidase activities into a single polypeptide. This naturally-occurring fusion protein offers new avenues for studying and engineering biotechnologically relevant enantioselective biochemical epoxidation reactions. Stopped-flow kinetic studies of StyA2B reported here identify reaction intermediates similar to those reported for the separate reductase and epoxidase components of related two-component systems. Our studies identify substrate epoxidation and elimination of water from the FAD C(4a)-hydroxide as rate-limiting steps in the styrene epoxidation reaction. Efforts directed at accelerating these reaction steps are expected to greatly increase catalytic efficiency and the value of StyA2B as biocatalyst.
Collapse
Affiliation(s)
- Dirk Tischler
- Interdisciplinary Ecological Center, TU Bergakadmie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany; Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands; Department of Chemistry and Biochemistry, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, United States.
| | | | | | | |
Collapse
|