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Ushimaru R. Three-membered ring formation catalyzed by α-ketoglutarate-dependent nonheme iron enzymes. J Nat Med 2024; 78:21-32. [PMID: 37980694 PMCID: PMC10764440 DOI: 10.1007/s11418-023-01760-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 10/25/2023] [Indexed: 11/21/2023]
Abstract
Epoxides, aziridines, and cyclopropanes are found in various medicinal natural products, including polyketides, terpenes, peptides, and alkaloids. Many classes of biosynthetic enzymes are involved in constructing these ring structures during their biosynthesis. This review summarizes our current knowledge regarding how α-ketoglutarate-dependent nonheme iron enzymes catalyze the formation of epoxides, aziridines, and cyclopropanes in nature, with a focus on enzyme mechanisms.
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Affiliation(s)
- Richiro Ushimaru
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo, 113-8657, Japan.
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2
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Slater JW, Lin CY, Neugebauer ME, McBride MJ, Sil D, Nair M, Katch BJ, Boal AK, Chang MC, Silakov A, Krebs C, Bollinger JM. Synergistic Binding of the Halide and Cationic Prime Substrate of l-Lysine 4-Chlorinase, BesD, in Both Ferrous and Ferryl States. Biochemistry 2023; 62:2480-2491. [PMID: 37542461 PMCID: PMC10829012 DOI: 10.1021/acs.biochem.3c00248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/07/2023]
Abstract
An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl- or Br-), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, the three nongaseous substrates must bind to activate the enzyme's Fe(II) cofactor for efficient capture of O2. Halide, 2OG, and (lastly) O2 all coordinate directly to the cofactor to initiate its conversion to a cis-halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H•) from the non-coordinating prime substrate to enable radicaloid carbon-halogen coupling. We dissected the kinetic pathway and thermodynamic linkage in binding of the first three substrates of the l-lysine 4-chlorinase, BesD. After addition of 2OG, subsequent coordination of the halide to the cofactor and binding of cationic l-Lys near the cofactor are associated with strong heterotropic cooperativity. Progression to the haloferryl intermediate upon the addition of O2 does not trap the substrates in the active site and, in fact, markedly diminishes cooperativity between halide and l-Lys. The surprising lability of the BesD•[Fe(IV)=O]•Cl•succinate•l-Lys complex engenders pathways for decay of the haloferryl intermediate that do not result in l-Lys chlorination, especially at low chloride concentrations; one identified pathway involves oxidation of glycerol. The mechanistic data imply (i) that BesD may have evolved from a hydroxylase ancestor either relatively recently or under weak selective pressure for efficient chlorination and (ii) that acquisition of its activity may have involved the emergence of linkage between l-Lys binding and chloride coordination following the loss of the anionic protein-carboxylate iron ligand present in extant hydroxylases.
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Affiliation(s)
- Jeffrey W. Slater
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
| | - Chi-Yun Lin
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
| | - Monica E. Neugebauer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, United States
- Present address: Department of Systems Biology, Harvard Medical School, Boston, MA 02115, United States
| | - Molly J. McBride
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Present address: Alliance Pharma, New York, NY 10065, United States
| | - Debangsu Sil
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Present address: Department of Chemistry, Indian Institute of Science Education & Research (IISER)-Pune, Pune-411008, India
| | - Mrutyunjay Nair
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
| | - Bryce J. Katch
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Present address: Tri-Institutional MD-PhD Program, Weill Cornell Medical College and Cornell University, New York, NY 10065, United States
| | - Amie K. Boal
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Michelle C.Y. Chang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, United States
- Departments of Chemistry and of Molecular and Cell Biology, University of California, Berkeley, and Lawrence Berkeley National Laboratory, Berkeley, CA 94720, United States
| | - Alexey Silakov
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
| | - J. Martin Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States
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3
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Slater JW, Neugebauer ME, McBride MJ, Sil D, Lin CY, Katch BJ, Boal AK, Chang MC, Silakov A, Krebs C, Bollinger JM. Synergistic Binding of the Halide and Cationic Prime Substrate of the l-Lysine 4-Chlorinase, BesD, in Both Ferrous and Ferryl States. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539147. [PMID: 37205437 PMCID: PMC10187165 DOI: 10.1101/2023.05.02.539147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl - or Br - ), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, the three non-gaseous substrates must bind to activate the enzyme's Fe(II) cofactor for efficient capture of O 2 . Halide, 2OG, and (lastly) O 2 all coordinate directly to the cofactor to initiate its conversion to a cis -halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H•) from the non-coordinating prime substrate to enable radicaloid carbon-halogen coupling. We dissected the kinetic pathway and thermodynamic linkage in binding of the first three substrates of the l -lysine 4-chlorinase, BesD. After 2OG adds, subsequent coordination of the halide to the cofactor and binding of cationic l -Lys near the cofactor are associated with strong heterotropic cooperativity. Progression to the haloferryl intermediate upon addition of O 2 does not trap the substrates in the active site and, in fact, markedly diminishes cooperativity between halide and l -Lys. The surprising lability of the BesD•[Fe(IV)=O]•Cl•succinate• l -Lys complex engenders pathways for decay of the haloferryl intermediate that do not result in l -Lys chlorination, especially at low chloride concentrations; one identified pathway involves oxidation of glycerol. The mechanistic data imply that (i) BesD may have evolved from a hydroxylase ancestor either relatively recently or under weak selective pressure for efficient chlorination and (ii) that acquisition of its activity may have involved the emergence of linkage between l -Lys binding and chloride coordination following loss of the anionic protein-carboxylate iron ligand present in extant hydroxylases.
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Affiliation(s)
- Jeffrey W. Slater
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Monica E. Neugebauer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA
- Present address: Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Molly J. McBride
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Debangsu Sil
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Chi-Yun Lin
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Bryce J. Katch
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Amie K. Boal
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Michelle C.Y. Chang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA, USA
- Departments of Chemistry and of Molecular and Cell Biology, University of California, Berkeley, and Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Alexey Silakov
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Carsten Krebs
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - J. Martin Bollinger
- Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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Panth N, Wenger ES, Krebs C, Bollinger JM, Grossman RB. Synthesis of 6,6- and 7,7-difluoro-1-acetamidopyrrolizidines and their oxidation catalyzed by the nonheme Fe oxygenase LolO. Chembiochem 2022; 23:e202200081. [PMID: 35482316 DOI: 10.1002/cbic.202200081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/26/2022] [Indexed: 11/11/2022]
Abstract
LolO, a 2-oxoglutarate-dependent nonheme Fe oxygenase, catalyzes both the hydroxylation and cycloetherification of 1- exo -acetamidopyrrolizidine (AcAP), a pathway intermediate in the biosynthesis of the loline alkaloids. We have prepared fluorinated AcAP analogs to aid in continued mechanistic investigation of the unusual LolO-catalyzed cycloetherification step. LolO was able to first hydroxylate and then cycloetherify 6,6-difluoro-AcAP (prepared from N , O -protected 4-oxoproline), forming a difluorinated analog of N -acetylnorloline (NANL) and providing evidence for a cycloetherification mechanism involving a C(7) radical as opposed to a C(7) carbocation. By contrast, LolO was able to hydroxylate 7,7-difluoro-AcAP (prepared from 3-oxoproline) but failed to cycloetherify it, forming (1 R , 2 R , 8 S )-7,7-difluoro-2-hydroxy-AcAP as the sole product. Because it completely blocks the cycloetherification step, 7,7-difluoro-AcAP has the potential to become an important tool for accumulating and characterizing the LolO intermediate responsible for catalyzing cycloetherification of 2-hydroxy-AcAP.
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Affiliation(s)
- Nabin Panth
- University of Kentucky, Chemistry, UNITED STATES
| | | | - Carsten Krebs
- The Pennsylvania State University, Chemistry; Biochemistry and Molecular Biology, UNITED STATES
| | - J Martin Bollinger
- The Pennsylvania State University, Chemistry; Biochemistry and Molecular Biology, UNITED STATES
| | - Robert B Grossman
- University of Kentucky, Chemistry, Chemistry-Physics Building, 40506-0055, Lexington, UNITED STATES
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5
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Tassano E, Moore C, Dussauge S, Vargas A, Snajdrova R. Discovery of New Fe(II)/α-Ketoglutarate-Dependent Dioxygenases for Oxidation of l-Proline. Org Process Res Dev 2022. [DOI: 10.1021/acs.oprd.1c00405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Erika Tassano
- Global Discovery Chemistry, Novartis Institute for Biomedical Research, 4056 Basel, Switzerland
| | - Charles Moore
- Global Discovery Chemistry, Novartis Institute for Biomedical Research, 4056 Basel, Switzerland
| | - Solene Dussauge
- Global Discovery Chemistry, Novartis Institute for Biomedical Research, 4056 Basel, Switzerland
| | - Alexandra Vargas
- Global Discovery Chemistry, Novartis Institute for Biomedical Research, 4056 Basel, Switzerland
| | - Radka Snajdrova
- Global Discovery Chemistry, Novartis Institute for Biomedical Research, 4056 Basel, Switzerland
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6
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Huang JP, Wang YJ, Tian T, Wang L, Yan Y, Huang SX. Tropane alkaloid biosynthesis: a centennial review. Nat Prod Rep 2021; 38:1634-1658. [PMID: 33533391 DOI: 10.1039/d0np00076k] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Covering: 1917 to 2020Tropane alkaloids (TAs) are a remarkable class of plant secondary metabolites, which are characterized by an 8-azabicyclo[3.2.1]octane (nortropane) ring. Members of this class, such as hyoscyamine, scopolamine, and cocaine, are well known for their long history as poisons, hallucinogens, and anaesthetic agents. Since the structure of the tropane ring system was first elucidated in 1901, organic chemists and biochemists have been interested in how these mysterious tropane alkaloids are assembled in vitro and in vivo. However, it was only in 2020 that the complete biosynthetic route of hyoscyamine and scopolamine was clarified, and their de novo production in yeast was also achieved. The aim of this review is to present the innovative ideas and results in exploring the story of tropane alkaloid biosynthesis in plants from 1917 to 2020. This review also highlights that Robinson's classic synthesis of tropinone, which is one hundred years old, is biomimetic, and underscores the importance of total synthesis in the study of natural product biosynthesis.
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Affiliation(s)
- Jian-Ping Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China. and State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
| | - Yong-Jiang Wang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
| | - Tian Tian
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China. and School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
| | - Li Wang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
| | - Yijun Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
| | - Sheng-Xiong Huang
- State Key Laboratory of Phytochemistry and Plant Resources in West China, CAS Center for Excellence in Molecular Plant Sciences, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China. and State Key Laboratory of Southwestern Chinese Medicine Resources, Innovative Institute of Chinese Medicine and Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China and School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
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7
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Kluza A, Wojdyla Z, Mrugala B, Kurpiewska K, Porebski PJ, Niedzialkowska E, Minor W, Weiss MS, Borowski T. Regioselectivity of hyoscyamine 6β-hydroxylase-catalysed hydroxylation as revealed by high-resolution structural information and QM/MM calculations. Dalton Trans 2020; 49:4454-4469. [PMID: 32182320 DOI: 10.1039/d0dt00302f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hyoscyamine 6β-hydroxylase (H6H) is a bifunctional non-heme 2-oxoglutarate/Fe2+-dependent dioxygenase that catalyzes the two final steps in the biosynthesis of scopolamine. Based on high resolution crystal structures of H6H from Datura metel, detailed information on substrate binding was obtained that provided insights into the onset of the enzymatic process. In particular, the role of two prominent residues was revealed - Glu-116 that interacts with the tertiary amine located on the hyoscyamine tropane moiety and Tyr-326 that forms CH-π hydrogen bonds with the hyoscyamine phenyl ring. The structures were used as the basis for QM/MM calculations that provided an explanation for the regioselectivity of the hydroxylation reaction on the hyoscyamine tropane moiety (C6 vs. C7) and quantified contributions of active site residues to respective barrier heights.
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Affiliation(s)
- Anna Kluza
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland.
| | - Zuzanna Wojdyla
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland.
| | - Beata Mrugala
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland.
| | - Katarzyna Kurpiewska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland. and Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, PL-30387 Krakow, Poland
| | - Przemyslaw J Porebski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland. and Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue Pinn Hall, Charlottesville, VA 22908, USA
| | - Ewa Niedzialkowska
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland. and Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue Pinn Hall, Charlottesville, VA 22908, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, 1340 Jefferson Park Avenue Pinn Hall, Charlottesville, VA 22908, USA
| | - Manfred S Weiss
- Macromolecular Crystallography, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Str. 15, D-12489, Berlin, Germany
| | - Tomasz Borowski
- Jerzy Haber Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Niezapominajek 8, PL-30239 Krakow, Poland.
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8
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Vila MA, Steck V, Rodriguez Giordano S, Carrera I, Fasan R. C-H Amination via Nitrene Transfer Catalyzed by Mononuclear Non-Heme Iron-Dependent Enzymes. Chembiochem 2020; 21:1981-1987. [PMID: 32189465 DOI: 10.1002/cbic.201900783] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 02/12/2020] [Indexed: 12/18/2022]
Abstract
Expanding the reaction scope of natural metalloenzymes can provide new opportunities for biocatalysis. Mononuclear non-heme iron-dependent enzymes represent a large class of biological catalysts involved in the biosynthesis of natural products and catabolism of xenobiotics, among other processes. Here, we report that several members of this enzyme family, including Rieske dioxygenases as well as α-ketoglutarate-dependent dioxygenases and halogenases, are able to catalyze the intramolecular C-H amination of a sulfonyl azide substrate, thereby exhibiting a promiscuous nitrene transfer reactivity. One of these enzymes, naphthalene dioxygenase (NDO), was further engineered resulting in several active site variants that function as C-H aminases. Furthermore, this enzyme could be applied to execute this non-native transformation on a gram scale in a bioreactor, thus demonstrating its potential for synthetic applications. These studies highlight the functional versatility of non-heme iron-dependent enzymes and pave the way to their further investigation and development as promising biocatalysts for non-native metal-catalyzed transformations.
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Affiliation(s)
- Maria Agustina Vila
- Laboratorio de Biocatálisis y Biotransformaciones, Departamento de Química Orgánica y Departamento de Biociencias. Facultad de Química, Universidad de la República, Av General Flores 2124, CP 11800, Montevideo, Uruguay
| | - Viktoria Steck
- Department of Chemistry, University of Rochester, RC Box 270216, Rochester, NY 14627, USA
| | - Sonia Rodriguez Giordano
- Laboratorio de Biocatálisis y Biotransformaciones, Departamento de Química Orgánica y Departamento de Biociencias. Facultad de Química, Universidad de la República, Av General Flores 2124, CP 11800, Montevideo, Uruguay
| | - Ignacio Carrera
- Laboratorio de Biocatálisis y Biotransformaciones, Departamento de Química Orgánica y Departamento de Biociencias. Facultad de Química, Universidad de la República, Av General Flores 2124, CP 11800, Montevideo, Uruguay
| | - Rudi Fasan
- Department of Chemistry, University of Rochester, RC Box 270216, Rochester, NY 14627, USA
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9
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Ushimaru R, Ruszczycky MW, Liu HW. Changes in Regioselectivity of H Atom Abstraction during the Hydroxylation and Cyclization Reactions Catalyzed by Hyoscyamine 6β-Hydroxylase. J Am Chem Soc 2018; 141:1062-1066. [PMID: 30545219 DOI: 10.1021/jacs.8b11585] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Hyoscyamine 6β-hydroxylase (H6H) is an αKG-dependent nonheme iron oxidase that catalyzes the oxidation of hyoscyamine to scopolamine via two separate reactions: hydroxylation followed by oxidative cyclization. Both of these reactions are expected to involve H atom abstraction from each of two adjacent carbon centers (C6 vs C7) in the substrate. During hydroxylation, there is a roughly 85:1 preference for H atom abstraction from C6 versus C7; however, this inverts to a 1:16 preference during cyclization. Furthermore, 18O incorporation experiments in the presence of deuterated substrate are consistent with the catalytic iron(IV)-oxo complex being able to support the coordination of an additional ligand during hydroxylation. These observations suggest that subtle differences in the substrate binding configuration can have significant consequences for the catalytic cycle of H6H.
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Affiliation(s)
- Richiro Ushimaru
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712 , United States
| | - Mark W Ruszczycky
- Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , TX 78712 , United States
| | - Hung-Wen Liu
- Department of Chemistry , University of Texas at Austin , Austin , TX 78712 , United States.,Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , TX 78712 , United States
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10
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Singh P, Prasad R, Tewari R, Jaidi M, Kumar S, Rout PK, Rahman LU. Silencing of quinolinic acid phosphoribosyl transferase (QPT) gene for enhanced production of scopolamine in hairy root culture of Duboisia leichhardtii. Sci Rep 2018; 8:13939. [PMID: 30224763 PMCID: PMC6141460 DOI: 10.1038/s41598-018-32396-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 08/23/2018] [Indexed: 11/09/2022] Open
Abstract
Scopolamine is a pharmaceutically important tropane alkaloid which is used therapeutically in the form of an anesthetic and antispasmodic drug. The present study demonstrates enhanced scopolamine production from transgenic hairy root clones of Duboisia leichhardtii wherein the expression of quinolinate phosphoribosyl transferase (QPT) gene was silenced using the QPT-RNAi construct under the control of CaMV 35 S promoter. The RNAi hairy roots clones viz. P4, P7, P8, and P12 showed the enhanced synthesis of scopolamine with significant inhibition of nicotine biosynthesis. Optimization of culture duration in combination with methyl jasmonate elicitor in different concentrations (50 µM-200 µM) was carried out. Maximum synthesis of scopolamine had obtained from HR clones P7 (8.84 ± 0.117 mg/gm) on the 30th day of cultivation. Conspicuously, elicitation with wound-associated hormone methyl jasmonate enhanced the yield of scopolamine 2.2 fold (19.344 ± 0.275 mg/gm) compared to the culture lacking the elicitor. The transgenic hairy roots cultures established with RNAi mediated silencing of quinolinate phosphoribosyl transferase gene provides an alternative approach to increase the yield of scopolamine in fulfilling the demand of this secondary metabolite.
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Affiliation(s)
- Pooja Singh
- Plant Biotechnology Division, Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Picnic Spot Road, Lucknow, U.P., 226015, India.,Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Institute of Medicinal and Aromatic Plants, Lucknow, 226015, India
| | - Ratnum Prasad
- Plant Biotechnology Division, Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Picnic Spot Road, Lucknow, U.P., 226015, India
| | - Rashi Tewari
- Chemical Science Division, Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Picnic Spot Road, Lucknow, U.P., 226015, India
| | - Meraj Jaidi
- Plant Molecular Virology Laboratory, CPMB Division, National Botanical Research Institute, Lucknow, U.P., 226001, India
| | - Susheel Kumar
- Plant Molecular Virology Laboratory, CPMB Division, National Botanical Research Institute, Lucknow, U.P., 226001, India
| | - P K Rout
- Chemical Science Division, Central Institute of Medicinal and Aromatic Plants, P.O. CIMAP, Picnic Spot Road, Lucknow, U.P., 226015, India
| | - Laiq Ur Rahman
- Plant Biotechnology Division, Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), P.O. CIMAP, Picnic Spot Road, Lucknow, U.P., 226015, India.
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11
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Ushimaru R, Ruszczycky MW, Chang WC, Yan F, Liu YN, Liu HW. Substrate Conformation Correlates with the Outcome of Hyoscyamine 6β-Hydroxylase Catalyzed Oxidation Reactions. J Am Chem Soc 2018; 140:7433-7436. [PMID: 29870653 DOI: 10.1021/jacs.8b03729] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hyoscyamine 6β-hydroxylase (H6H) is an α-ketoglutarate dependent mononuclear nonheme iron enzyme that catalyzes C6-hydroxylation of hyoscyamine and oxidative cyclization of the resulting product to give the oxirane natural product scopolamine. Herein, the chemistry of H6H is investigated using hyoscyamine derivatives with modifications at the C6 or C7 position as well as substrate analogues possessing a 9-azabicyclo[3.3.1]nonane core. Results indicate that hydroxyl rebound is unlikely to take place during the cyclization reaction and that the hydroxylase versus oxidative cyclase activity of H6H is correlated with the presence of an exo-hydroxy group having syn-periplanar geometry with respect to the adjacent H atom to be abstracted.
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Affiliation(s)
- Richiro Ushimaru
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Mark W Ruszczycky
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Wei-Chen Chang
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Feng Yan
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Yung-Nan Liu
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
| | - Hung-Wen Liu
- Department of Chemistry, and Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy , University of Texas at Austin , Austin , Texas 78712 , United States
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12
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Pan J, Bhardwaj M, Zhang B, Chang WC, Schardl CL, Krebs C, Grossman RB, Bollinger JM. Installation of the Ether Bridge of Lolines by the Iron- and 2-Oxoglutarate-Dependent Oxygenase, LolO: Regio- and Stereochemistry of Sequential Hydroxylation and Oxacyclization Reactions. Biochemistry 2018. [PMID: 29537853 PMCID: PMC5895980 DOI: 10.1021/acs.biochem.8b00157] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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The core of the loline
family of insecticidal alkaloids is the
bicyclic pyrrolizidine unit with an additional strained ether bridge
between carbons 2 and 7. Previously reported genetic and in
vivo biochemical analyses showed that the presumptive iron-
and 2-oxoglutarate-dependent (Fe/2OG) oxygenase, LolO, is required
for installation of the ether bridge upon the pathway intermediate,
1-exo-acetamidopyrrolizidine (AcAP). Here we show
that LolO is, in fact, solely responsible for this biosynthetic four-electron
oxidation. In sequential 2OG- and O2-consuming steps, LolO
removes hydrogens from C2 and C7 of AcAP to form both carbon–oxygen
bonds in N-acetylnorloline (NANL), the precursor
to all other lolines. When supplied with substoichiometric 2OG, LolO
only hydroxylates AcAP. At higher 2OG:AcAP ratios, the enzyme further
processes the alcohol to the tricyclic NANL. Characterization of the
alcohol intermediate by mass spectrometry and nuclear magnetic resonance
spectroscopy shows that it is 2-endo-hydroxy-1-exo-acetamidopyrrolizidine (2-endo-OH-AcAP).
Kinetic and spectroscopic analyses of reactions with site-specifically
deuteriated AcAP substrates confirm that the C2–H bond is cleaved
first and that the responsible intermediate is, as expected, an FeIV–oxo (ferryl) complex. Analyses of the loline products
from cultures fed with stereospecifically deuteriated AcAP precursors,
proline and aspartic acid, establish that LolO removes the endo hydrogens
from C2 and C7 and forms both new C–O bonds with retention
of configuration. These findings delineate the pathway to an important
class of natural insecticides and lay the foundation for mechanistic
dissection of the chemically challenging oxacyclization reaction.
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Affiliation(s)
- Juan Pan
- Department of Chemistry and Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | | | - Bo Zhang
- Department of Chemistry and Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - Wei-Chen Chang
- Department of Chemistry and Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | | | - Carsten Krebs
- Department of Chemistry and Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | | | - J Martin Bollinger
- Department of Chemistry and Department of Biochemistry and Molecular Biology , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
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Nguyen TKO, Jamali A, Lanoue A, Gontier E, Dauwe R. Unravelling the architecture and dynamics of tropane alkaloid biosynthesis pathways using metabolite correlation networks. PHYTOCHEMISTRY 2015; 116:94-103. [PMID: 25823585 DOI: 10.1016/j.phytochem.2015.03.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 03/06/2015] [Accepted: 03/13/2015] [Indexed: 05/04/2023]
Abstract
The tropane alkaloid spectrum in Solanaceae is highly variable within and between species. Little is known about the topology and the coordination of the biosynthetic pathways leading to the variety of tropine and pseudotropine derived esters in the alkaloid spectrum, or about the metabolic dynamics induced by tropane alkaloid biosynthesis stimulating conditions. A good understanding of the metabolism, including all ramifications, is however necessary for the development of strategies to increase the abundance of pharmacologically interesting compounds such as hyoscyamine and scopolamine. The present study explores the tropane alkaloid metabolic pathways in an untargeted approach involving a correlation-based network analysis. Using GC-MS metabolite profiling, the variation and co-variation among tropane alkaloids and primary metabolites was monitored in 60 Datura innoxia Mill. individuals, of which half were exposed to tropane alkaloid biosynthesis stimulating conditions by co-culture with Agrobacterium rhizogenes. Considerable variation was evident in the relative proportions of the tropane alkaloids. Remodeling of the tropane alkaloid spectrum under co-culture with A. rhizogenes involved a specific and strong increase of hyoscyamine production and revealed that the accumulation of hyoscyamine, 3-tigloyloxy-6,7-epoxytropane, and 3-methylbutyryloxytropane was controlled independently of the majority of tropane alkaloids. Based on correlations between metabolites, we propose a biosynthetic origin of hygrine, the order of esterification of certain di-oxygenated tropanes, and that the rate of acetoxylation contributes to control of hyoscyamine production. Overall, this study shows that the biosynthesis of tropane alkaloids may be far more complex and finely controlled than previously expected.
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Affiliation(s)
- Thi-Kieu-Oanh Nguyen
- EA3900 BioPI, University of Picardy Jules Verne, UFR Sciences, 33 rue Saint Leu, 80039 Amiens cedex, France.
| | - Arash Jamali
- EA3900 BioPI, University of Picardy Jules Verne, UFR Pharmacie, 1 rue des Louvels, 80039 Amiens cedex, France.
| | - Arnaud Lanoue
- Laboratoire de biologie cellulaire et biochimie végétale, University of Tours, UFR de Sciences Pharmaceutiques, 31 Avenue Monge, 37200 Tours, France.
| | - Eric Gontier
- EA3900 BioPI, University of Picardy Jules Verne, UFR Sciences, 33 rue Saint Leu, 80039 Amiens cedex, France.
| | - Rebecca Dauwe
- EA3900 BioPI, University of Picardy Jules Verne, UFR Sciences, 33 rue Saint Leu, 80039 Amiens cedex, France.
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14
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Gandhi SG, Mahajan V, Bedi YS. Changing trends in biotechnology of secondary metabolism in medicinal and aromatic plants. PLANTA 2015; 241:303-17. [PMID: 25549846 DOI: 10.1007/s00425-014-2232-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 12/16/2014] [Indexed: 05/02/2023]
Abstract
Medicinal and aromatic plants are known to produce secondary metabolites that find uses as flavoring agents, fragrances, insecticides, dyes and drugs. Biotechnology offers several choices through which secondary metabolism in medicinal plants can be altered in innovative ways, to overproduce phytochemicals of interest, to reduce the content of toxic compounds or even to produce novel chemicals. Detailed investigation of chromatin organization and microRNAs affecting biosynthesis of secondary metabolites as well as exploring cryptic biosynthetic clusters and synthetic biology options, may provide additional ways to harness this resource. Plant secondary metabolites are a fascinating class of phytochemicals exhibiting immense chemical diversity. Considerable enigma regarding their natural biological functions and the vast array of pharmacological activities, amongst other uses, make secondary metabolites interesting and important candidates for research. Here, we present an update on changing trends in the biotechnological approaches that are used to understand and exploit the secondary metabolism in medicinal and aromatic plants. Bioprocessing in the form of suspension culture, organ culture or transformed hairy roots has been successful in scaling up secondary metabolite production in many cases. Pathway elucidation and metabolic engineering have been useful to get enhanced yield of the metabolite of interest; or, for producing novel metabolites. Heterologous expression of putative plant secondary metabolite biosynthesis genes in a microbe is useful to validate their functions, and in some cases, also, to produce plant metabolites in microbes. Endophytes, the microbes that normally colonize plant tissues, may also produce the phytochemicals produced by the host plant. The review also provides perspectives on future research in the field.
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Affiliation(s)
- Sumit G Gandhi
- Plant Biotechnology Division, Indian Institute of Integrative Medicine (CSIR-IIIM), Council of Scientific and Industrial Research, Canal Road, Jammu Tawi, 180001, India,
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15
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Li J, van Belkum MJ, Vederas JC. Functional characterization of recombinant hyoscyamine 6β-hydroxylase from Atropa belladonna. Bioorg Med Chem 2012; 20:4356-63. [PMID: 22705021 DOI: 10.1016/j.bmc.2012.05.042] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 05/09/2012] [Accepted: 05/17/2012] [Indexed: 11/15/2022]
Abstract
(-)-Hyoscyamine, the enantiomerically pure form of atropine, and its derivative scopolamine are tropane alkaloids that are extensively used in medicine. Hyoscyamine 6β-hydroxylase (H6H, EC 1.14.11.11), a monomeric α-ketoglutarate dependent dioxygenase, converts (-)-hyoscyamine to its 6,7-epoxy derivative, scopolamine, in two sequential steps. In this study, H6H of Atropa belladonna (AbH6H) was cloned, heterologously expressed in Escherichia coli, purified and characterized. The catalytic efficiency of AbH6H, especially for the second oxidation, was found to be low, and this may be one of the reasons why Atropa belladonna produces less scopolamine than other species in the same family. 6,7-Dehydrohyoscyamine, a potential precursor for the last step of epoxidation, was shown not to be an obligatory intermediate in the biosynthesis of scopolamine using purified AbH6H with an in vitro (18)O labeling experiment. Moreover, the nitrogen atom in the tropane ring of (-)-hyoscyamine was found to play an important role in substrate recognition.
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Affiliation(s)
- Jing Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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16
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Thibodeaux CJ, Chang WC, Liu HW. Enzymatic chemistry of cyclopropane, epoxide, and aziridine biosynthesis. Chem Rev 2012; 112:1681-709. [PMID: 22017381 PMCID: PMC3288687 DOI: 10.1021/cr200073d] [Citation(s) in RCA: 202] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Wei-chen Chang
- College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Hung-wen Liu
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, Texas 78712
- College of Pharmacy and Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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17
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Endo T, Hamaguchi N, Hashimoto T, Yamada Y. Non-enzymatic synthesis of hygrine from acetoacetic acid and from acetonedicarboxylic acid. FEBS Lett 2001. [DOI: 10.1016/0014-5793(88)81309-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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19
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Rhodes MJ. Physiological roles for secondary metabolites in plants: some progress, many outstanding problems. PLANT MOLECULAR BIOLOGY 1994; 24:1-20. [PMID: 8111009 DOI: 10.1007/bf00040570] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- M J Rhodes
- AFRC Institute of Food Research, Norwich Research Park, Colney, Norfolk, UK
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20
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Hashimoto T, Matsuda J, Yamada Y. Two-step epoxidation of hyoscyamine to scopolamine is catalyzed by bifunctional hyoscyamine 6 beta-hydroxylase. FEBS Lett 1993; 329:35-9. [PMID: 8354403 DOI: 10.1016/0014-5793(93)80187-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
In several solanaceous plants, hyoscyamine is first hydroxylated at the 6 beta-position, and then epoxidized to scopolamine. We expressed hyoscyamine 6 beta-hydroxylase (H6H) in Escherichia coli as a fusion protein with maltose-binding protein. The crude cell extract from the bacterium that expressed the soluble fusion protein showed a strong hydroxylase activity and a weak epoxidase activity. When 100 microM of hyoscyamine was fed to the recombinant bacterium, the alkaloid was first converted to 6 beta-hydroxy hyoscyamine, and then to scopolamine, which was almost the only alkaloid found in the culture after one week. Therefore, H6H catalyzes two consecutive reactions that oxidize hyoscyamine to scopolamine.
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Affiliation(s)
- T Hashimoto
- Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Japan
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21
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Robins RJ, Walton NJ. Chapter 2 The Biosynthesis of Tropane Alkaloids. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/s0099-9598(08)60144-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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22
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Yun DJ, Hashimoto T, Yamada Y. Metabolic engineering of medicinal plants: transgenic Atropa belladonna with an improved alkaloid composition. Proc Natl Acad Sci U S A 1992; 89:11799-803. [PMID: 1465402 PMCID: PMC50644 DOI: 10.1073/pnas.89.24.11799] [Citation(s) in RCA: 224] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The tropane alkaloid scopolamine is a medicinally important anticholinergic drug present in several solanaceous plants. Hyoscyamine 6 beta-hydroxylase (EC 1.14.11.11) catalyzes the oxidative reactions in the biosynthetic pathway leading from hyoscyamine to scopolamine. We introduced the hydroxylase gene from Hyoscyamus niger under the control of the cauliflower mosaic virus 35S promoter into hyoscyamine-rich Atropa belladonna by the use of an Agrobacterium-mediated transformation system. A transgenic plant that constitutively and strongly expressed the transgene was selected, first by screening for kanamycin resistance and then by immunoscreening leaf samples with an antibody specific for the hydroxylase. In the primary transformant and its selfed progeny that inherited the transgene, the alkaloid contents of the leaf and stem were almost exclusively scopolamine. Such metabolically engineered plants should prove useful as breeding materials for obtaining improved medicinal components.
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Affiliation(s)
- D J Yun
- Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Japan
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Hashimoto T, Hayashi A, Amano Y, Kohno J, Iwanari H, Usuda S, Yamada Y. Hyoscyamine 6β-hydroxylase, an enzyme involved in tropane alkaloid biosynthesis, is localized at the pericycle of the root. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(20)64371-x] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Verpoorte R, van der Heijden R, van Gulik WM, ten Hoopen HJ. Chapter 1 Plant Biotechnology for the Production of Alkaloids: Present Status and Prospects. THE ALKALOIDS: CHEMISTRY AND PHARMACOLOGY 1991. [DOI: 10.1016/s0099-9598(08)60268-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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