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Fukuda Y, Watanabe T, Hoshino T. Mutated variants of squalene-hopene cyclase: enzymatic syntheses of triterpenes bearing oxygen-bridged monocycles and a new 6,6,6,6,6-fusded pentacyclic scaffold, named neogammacerane, from 2,3-oxidosqualene. Org Biomol Chem 2019; 16:8365-8378. [PMID: 30209480 DOI: 10.1039/c8ob02009d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Squalene-hopene cyclase (SHC) catalyzes the conversion of acyclic squalene molecule into a 6,6,6,6,5-fused pentacyclic hopene and hopanol. SHC is also able to convert (3S)-2,3-oxidosqualene into 3β-hydroxyhopene and 3β-hydroxyhopanol and can generate 3α-hydroxyhopene and 3α-hydroxyhopanol from (3R)-2,3-oxidosqualene. Functional analyses of active site residues toward the squalene cyclization reaction have been extensively reported, but investigations of the cyclization reactions of (3R,S)-oxidosqualene by SHC have rarely been reported. The cyclization reactions of oxidosqualene with W169X, G600F/F601G and F601G/P602F were examined. The variants of the W169L generated new triterpene skeletons possessing a 7-oxabicyclo[2.2.1]heptane moiety (oxygen-bridged monocycle) with (1S,2S,4R)- and (1R,2S,4S)-stereochemistry, which were produced from (3R)- and (3S)-oxidosqualenes, respectively. The F601G/P602F double mutant also furnished a novel triterpene, named neogammacer-21(22)-en-3β-ol, consisting of a 6,6,6,6,6-fused pentacyclic system, in which Me-29 at C-22 of the gammacerane skeleton migrated to C-21. We propose to name this novel scaffold neogammacerane. The formation mechanisms of the enzymatic products from 2,3-oxidosqualene are discussed.
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Affiliation(s)
- Yoriyuki Fukuda
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan.
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2
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Nakano C, Watanabe T, Minamino M, Hoshino T. Enzymatic syntheses of novel carbocyclic scaffolds with a 6,5 + 5,5 ring system by squalene-hopene cyclase. Org Biomol Chem 2019; 17:9375-9389. [DOI: 10.1039/c9ob01941c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel scaffold with a 6,5 + 5, 5 ring system (allodammarane) was synthesized from 27-norsqualene (13a), 3R-(18) and 3S-27-noroxidosqualenes (19).
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Affiliation(s)
- Chiaki Nakano
- Department of Applied Biological Chemistry
- Faculty of Agriculture
- and Graduate School of Science and Technology
- Niigata University
- Niigata
| | - Takumi Watanabe
- Department of Applied Biological Chemistry
- Faculty of Agriculture
- and Graduate School of Science and Technology
- Niigata University
- Niigata
| | - Mai Minamino
- Department of Applied Biological Chemistry
- Faculty of Agriculture
- and Graduate School of Science and Technology
- Niigata University
- Niigata
| | - Tsutomu Hoshino
- Department of Applied Biological Chemistry
- Faculty of Agriculture
- and Graduate School of Science and Technology
- Niigata University
- Niigata
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3
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Kaneko I, Terasawa Y, Hoshino T. Squalene-Hopene Cyclase: Mechanistic Insights into the Polycyclization Cascades of Squalene Analogs Bearing Ethyl and Hydroxymethyl Groups at the C-2 and C-23 Positions. Chemistry 2018; 24:11139-11157. [DOI: 10.1002/chem.201801668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Ikki Kaneko
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture; Niigata University; Ikarashi 2-8050 Nishi-ku Niigata 950-2181 Japan
| | - Yuri Terasawa
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture; Niigata University; Ikarashi 2-8050 Nishi-ku Niigata 950-2181 Japan
| | - Tsutomu Hoshino
- Graduate School of Science and Technology and Department of Applied Biological Chemistry, Faculty of Agriculture; Niigata University; Ikarashi 2-8050 Nishi-ku Niigata 950-2181 Japan
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4
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Kühnel LC, Nestl BM, Hauer B. Enzymatic Addition of Alcohols to Terpenes by Squalene Hopene Cyclase Variants. Chembiochem 2017; 18:2222-2225. [PMID: 28898524 DOI: 10.1002/cbic.201700449] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Indexed: 11/07/2022]
Abstract
Squalene-hopene cyclases (SHCs) catalyze the polycyclization of squalene into a mixture of hopene and hopanol. Recently, amino-acid residues lining the catalytic cavity of the SHC from Alicyclobacillus acidocaldarius were replaced by small and large hydrophobic amino acids. The alteration of leucine 607 to phenylalanine resulted in increased enzymatic activity towards the formation of an intermolecular farnesyl-farnesyl ether product from farnesol. Furthermore, the addition of small-chain alcohols acting as nucleophiles led to the formation of non-natural ether-linked terpenoids and, thus, to significant alteration of the product pattern relative to that obtained with the wild type. It is proposed that the mutation of leucine at position 607 may facilitate premature quenching of the intermediate by small alcohol nucleophiles. This mutagenesis-based study opens the field for further intermolecular bond-forming reactions and the generation of non-natural products.
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Affiliation(s)
- Lisa C Kühnel
- Institute of Biochemistry and Technical Biochemistry, Universitaet Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Bettina M Nestl
- Institute of Biochemistry and Technical Biochemistry, Universitaet Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Bernhard Hauer
- Institute of Biochemistry and Technical Biochemistry, Universitaet Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
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5
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Hoshino T. β-Amyrin biosynthesis: catalytic mechanism and substrate recognition. Org Biomol Chem 2017; 15:2869-2891. [DOI: 10.1039/c7ob00238f] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In the past five years, there have been remarkable advances in the study of β-amyrin synthase. This review outlines the catalytic mechanism and substrate recognition in β-amyrin biosynthesis, which have been attained by the site-directed mutagenesis and substrate analog experiments.
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Affiliation(s)
- Tsutomu Hoshino
- Graduate School of Science and Technology and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181
- Japan
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6
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Cheng J, Nakano C, Shi GL, Hoshino T. Further Insight into Polycyclization Cascades of Acyclic Geranylfarnesol and its Acetate by Squalene-hopene Cyclase from Alicyclobacillus Acidocaldarius. Nat Prod Commun 2016. [DOI: 10.1177/1934578x1601100207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The enzymatic reactions of geranylfarnesol (8) and its acetate 9, classified as sesterterpenes (C25), using squalene-hopene cyclase (SHC) were investigated. The enzymatic reaction of 8 afforded 6/6-fused bicyclic 20, 6/6/6-fused tricyclic 21, and 6/6/6/6-fused tetracyclic compounds 22 and 23 as the main products (35% yield), whereas that of 9 afforded two 6/6/6-fused tricyclic compounds 24 and 25 in a high yield (76.3%) and a small amount (5.0%) of 26 (the acetate of 22). A significantly higher conversion of 9 indicates that the arrangement of the substrate in the reaction cavity changed. The lipophilic nature and/or the bulkiness of the acetyl group may have changed its binding with SHC, thus placing the terminal double bond of 9 in the vicinity of the DXDD motif of SHC, which is responsible for the proton attack on the double bond to initiate the polycyclization reaction. The results obtained for 8 are different to some extent than those reported by Shinozaki et al. The products obtained in this study were deprotonated compounds; however, the products reported by Shinozaki et al. were hydroxylated compounds.
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Affiliation(s)
- Jun Cheng
- Key Laboratory of Unban Agriculture (North) Ministry of Agriculture, College of Biological Science and Engineering, Beijing University of Agriculture, Beijing, P.R. China 102206
| | - Chiaki Nakano
- Department of Applied Biological Chemistry, Faculty of Agriculture and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata, Japan 950-2181
| | - Guang Lu Shi
- Key Laboratory of Unban Agriculture (North) Ministry of Agriculture, College of Biological Science and Engineering, Beijing University of Agriculture, Beijing, P.R. China 102206
| | - Tsutomu Hoshino
- Department of Applied Biological Chemistry, Faculty of Agriculture and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata, Japan 950-2181
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Hoshino T, Miyahara Y, Hanaoka M, Takahashi K, Kaneko I. β-Amyrin Biosynthesis: The Methyl-30 Group of (3S)-2,3-Oxidosqualene Is More Critical to Its Correct Folding To Generate the Pentacyclic Scaffold than the Methyl-24 Group. Chemistry 2015; 21:15769-84. [DOI: 10.1002/chem.201502389] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Indexed: 11/11/2022]
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8
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Hoshino T, Yamaguchi Y, Takahashi K, Ito R. β-Amyrin Biosynthesis: The Critical Role of Steric Volume at C-19 of 2,3-Oxidosqualene for Its Correct Folding To Generate the Pentacyclic Scaffold. Org Lett 2014; 16:3548-51. [DOI: 10.1021/ol501498q] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tsutomu Hoshino
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Yuki Yamaguchi
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Kazunari Takahashi
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Ryousuke Ito
- Graduate School of Science
and Technology, and Department of Applied Biological Chemistry, Faculty
of Agriculture, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
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9
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Ito R, Masukawa Y, Nakada C, Amari K, Nakano C, Hoshino T. β-Amyrin synthase from Euphorbia tirucalli. Steric bulk, not the π-electrons of Phe, at position 474 has a key role in affording the correct folding of the substrate to complete the normal polycyclization cascade. Org Biomol Chem 2014; 12:3836-46. [DOI: 10.1039/c4ob00064a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The importance of the steric bulk at 474 residue is described for completion of the cyclization cascade, but not the π-electrons of the Phe residue.
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Affiliation(s)
- Ryousuke Ito
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Yukari Masukawa
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Chika Nakada
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Kanako Amari
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Chiaki Nakano
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
| | - Tsutomu Hoshino
- Graduate School of Science and Technology
- and Department of Applied Biological Chemistry
- Faculty of Agriculture
- Niigata University
- Niigata 950-2181, Japan
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10
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Ito R, Hashimoto I, Masukawa Y, Hoshino T. Effect of Cation-π Interactions and Steric Bulk on the Catalytic Action of Oxidosqualene Cyclase: A Case Study of Phe728 of β-Amyrin Synthase fromEuphorbia tirucalli L. Chemistry 2013; 19:17150-8. [DOI: 10.1002/chem.201301917] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Revised: 08/31/2013] [Indexed: 11/06/2022]
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11
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Hammer SC, Syrén PO, Seitz M, Nestl BM, Hauer B. Squalene hopene cyclases: highly promiscuous and evolvable catalysts for stereoselective CC and CX bond formation. Curr Opin Chem Biol 2013; 17:293-300. [PMID: 23485581 DOI: 10.1016/j.cbpa.2013.01.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 01/20/2013] [Accepted: 01/23/2013] [Indexed: 11/18/2022]
Abstract
We review here how the inherent promiscuous nature, as well as the evolvability of terpene cyclase enzymes enables new applications in chemistry. We mainly focus on squalene hopene cyclases, class II triterpene synthases that use a proton-initiated cationic polycyclization cascade to form carbopolycyclic products. We highlight recent findings to demonstrate that these enzymes are capable of activating different functionalities other than the traditional terminal isoprene C=C-group as well as being compatible with a wide range of nucleophiles beyond the 'ene-functionality'. Thus, squalene hopene cyclases demonstrate a great potential to be used as a toolbox for general Brønsted acid catalysis.
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Affiliation(s)
- Stephan C Hammer
- Institute of Technical Biochemistry, Universitaet Stuttgart, Allmandring 31, D-70569 Stuttgart, Germany
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12
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Siedenburg G, Breuer M, Jendrossek D. Prokaryotic squalene-hopene cyclases can be converted to citronellal cyclases by single amino acid exchange. Appl Microbiol Biotechnol 2012; 97:1571-80. [PMID: 22526778 DOI: 10.1007/s00253-012-4008-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 03/02/2012] [Accepted: 03/04/2012] [Indexed: 10/28/2022]
Abstract
Squalene-hopene cyclases (SHCs) are prokaryotic enzymes that catalyse the cyclisation of the linear precursor squalene to pentacyclic hopene. Recently, we discovered that a SHC cloned from Zymomonas mobilis (ZMO-1548 gene product) has the unique property to cyclise the monoterpenoid citronellal to isopulegol. In this study, we performed saturation mutagenesis of three amino acids of the catalytic centre of ZMO-1548 (F428, F486 and W555), which had been previously identified to interact with enzyme-bound substrate. Replacement of F428 by tyrosine increased hopene formation from squalene, but isopulegol-forming activity was strongly reduced or abolished in all muteins of position 428. W555 was essential for hopene formation; however, three muteins (W555Y, W428F or W555T) revealed enhanced cyclisation efficiency with citronellal. The residue at position 486 turned out to be the most important for isopulegol-forming activity. While the presence of phenylalanine or tyrosine favoured cyclisation activity with squalene, several small and/or hydrophobic residues such as cysteine, alanine or isoleucine and others reduced activity with squalene but greatly enhanced isopulegol formation from citronellal. Replacement of the conserved aromatic residue corresponding to F486 to cysteine in other SHCs cloned from Z. mobilis (ZMO-0872), Alicyclobacillus acidocaldarius (SHC(Aac)), Acetobacter pasteurianus (SHC(Apa)), Streptomyces coelicolor (SHC(Sco)) and Bradyrhizobium japonicum (SHC(Bja)) resulted in more or less strong isopulegol-forming activities from citronellal. In conclusion, many SHCs can be converted to citronellal cyclases by mutagenesis of the active centre thus broadening the applicability of this interesting class of biocatalyst.
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Affiliation(s)
- Gabriele Siedenburg
- Institute of Microbiology, University of Stuttgart, Allmandring 31, 70550 Stuttgart, Germany
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Yonemura Y, Ohyama T, Hoshino T. Chemo-enzymatic syntheses of drimane-type sesquiterpenes and the fundamental core of hongoquercin meroterpenoid by recombinant squalene–hopene cyclase. Org Biomol Chem 2012; 10:440-6. [DOI: 10.1039/c1ob06419c] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Sato T, Hoshino H, Yoshida S, Nakajima M, Hoshino T. Bifunctional Triterpene/Sesquarterpene Cyclase: Tetraprenyl-β-curcumene Cyclase Is Also Squalene Cyclase in Bacillus megaterium. J Am Chem Soc 2011; 133:17540-3. [DOI: 10.1021/ja2060319] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tsutomu Sato
- Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Hiroko Hoshino
- Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Satoru Yoshida
- Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Mami Nakajima
- Center for Instrumental Analysis, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
| | - Tsutomu Hoshino
- Department of Applied Biological Chemistry, Faculty of Agriculture, and Graduate School of Science and Technology, Niigata University, Ikarashi 2-8050, Nishi-ku, Niigata 950-2181, Japan
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Abstract
Hopanoids and sterols are members of a large group of cyclic triterpenoic compounds that have important functions in many prokaryotic and eukaryotic organisms. They are biochemically synthesized from linear precursors (squalene, 2,3-oxidosqualene) in only one enzymatic step that is catalyzed by squalene-hopene cyclase (SHC) or oxidosqualene cyclase (OSC). SHCs and OSCs are related in amino acid sequences and probably are derived from a common ancestor. The SHC reaction requires the formation of five ring structures, 13 covalent bonds, and nine stereo centers and therefore is one of the most complex one-step enzymatic reactions. We summarize the knowledge of the properties of triterpene cyclases and details of the reaction mechanism of Alicyclobacillus acidocaldarius SHC. Properties of other SHCs are included.
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Affiliation(s)
| | - Dieter Jendrossek
- Institute for Microbiology, University of Stuttgart, Stuttgart, Germany
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Nakano C, Hoshino T, Sato T, Toyomasu T, Dairi T, Sassa T. Substrate specificity of the CYC2 enzyme from Kitasatospora griseola: production of sclarene, biformene, and novel bicyclic diterpenes by the enzymatic reactions of labdane- and halimane-type diterpene diphosphates. Tetrahedron Lett 2010. [DOI: 10.1016/j.tetlet.2009.10.110] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Raptis C, Lykakis I, Tsangarakis C, Stratakis M. Acid-Catalyzed Cyclization of Terpenes Under Homogeneous and Heterogeneous Conditions as Probed Through Stereoisotopic Studies: A Concerted Process with Competing Preorganized Chair and Boat Transition States. Chemistry 2009; 15:11918-27. [DOI: 10.1002/chem.200901563] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Cheng J, Hoshino T. Cyclization cascade of the C33-bisnorheptaprenoid catalyzed by recombinant squalene cyclase. Org Biomol Chem 2009; 7:1689-99. [PMID: 19343258 DOI: 10.1039/b823167b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The enzymatic cyclization reaction of polyprenoid C(33) by squalene-hopene cyclase (SHC) was investigated with the intention of creating an unnatural hexacyclic compound. The enzymatic products consisted of mono-, bi-, tri-, tetra- and pentacyclic skeletons; however, hexacyclic products were not generated, contrary to our expectations. The absence of a hexacyclic skeleton indicated that the entire carbon chain of C(33) polyprene could not be included in the reaction cavity. Formation mechanisms of the products having mono- to pentacycles were discussed. Both chair/chair/boat conformation and chair/chair/chair conformations were formed for a tricycle, and both chair/chair/chair/boat conformation and chair/chair/chair/chair structures were constructed for a tetracycle. The pentacyclic product was created from the chair/chair/chair/chair/boat conformation. Squalene was folded in an all pre-chair conformation inside the reaction cavity to form the hopene skeleton. Therefore, the formation of a boat structure during the polycyclization reaction indicated that the molecule of polyprene C(33) was folded improperly due to incorrect arrangement/positioning in the reaction cavity. The creation of the hexacyclic core failed; however, it should be noted that SHC possessed great potential to tolerate the elongated squalene analog C(33), thus leading to the creation of novel compounds with C(33).
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Affiliation(s)
- Jun Cheng
- Department of Applied Biological Chemistry, Faculty of Agriculture and Graduate School of Science and Technology, Niigata University, Ikarashi 2, Nishi-ku, Niigata 950-2181, Japan
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