1
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Chandramohan A, Josien H, Yuen TY, Duggal R, Spiegelberg D, Yan L, Juang YCA, Ge L, Aronica PG, Kaan HYK, Lim YH, Peier A, Sherborne B, Hochman J, Lin S, Biswas K, Nestor M, Verma CS, Lane DP, Sawyer TK, Garbaccio R, Henry B, Kannan S, Brown CJ, Johannes CW, Partridge AW. Design-rules for stapled peptides with in vivo activity and their application to Mdm2/X antagonists. Nat Commun 2024; 15:489. [PMID: 38216578 PMCID: PMC10786919 DOI: 10.1038/s41467-023-43346-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 11/06/2023] [Indexed: 01/14/2024] Open
Abstract
Although stapled α-helical peptides can address challenging targets, their advancement is impeded by poor understandings for making them cell permeable while avoiding off-target toxicities. By synthesizing >350 molecules, we present workflows for identifying stapled peptides against Mdm2(X) with in vivo activity and no off-target effects. Key insights include a clear correlation between lipophilicity and permeability, removal of positive charge to avoid off-target toxicities, judicious anionic residue placement to enhance solubility/behavior, optimization of C-terminal length/helicity to enhance potency, and optimization of staple type/number to avoid polypharmacology. Workflow application gives peptides with >292x improved cell proliferation potencies and no off-target cell proliferation effects ( > 3800x on-target index). Application of these 'design rules' to a distinct Mdm2(X) peptide series improves ( > 150x) cellular potencies and removes off-target toxicities. The outlined workflow should facilitate therapeutic impacts, especially for those targets such as Mdm2(X) that have hydrophobic interfaces and are targetable with a helical motif.
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Affiliation(s)
| | | | - Tsz Ying Yuen
- Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (ASTAR), Singapore, 138665, Singapore
| | | | - Diana Spiegelberg
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Lin Yan
- Merck & Co., Inc., Kenilworth, NJ, 07033, USA
| | | | - Lan Ge
- Merck & Co., Inc., Kenilworth, NJ, 07033, USA
| | - Pietro G Aronica
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, 138671, Singapore
| | | | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (ASTAR), Singapore, 138665, Singapore
| | | | | | | | | | | | - Marika Nestor
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Chandra S Verma
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, 138671, Singapore
| | - David P Lane
- Institute of Molecular and Cell Biology, Singapore, 138673, Singapore
| | | | | | - Brian Henry
- MSD International, Singapore, 138665, Singapore.
| | - Srinivasaraghavan Kannan
- Bioinformatics Institute, Agency for Science, Technology and Research (ASTAR), Singapore, 138671, Singapore.
| | | | - Charles W Johannes
- Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (ASTAR), Singapore, 138665, Singapore.
- Institute of Molecular and Cell Biology, Singapore, 138673, Singapore.
- EPOC Scientific LLC, Stoneham, MA, 02180, USA.
| | - Anthony W Partridge
- MSD International, Singapore, 138665, Singapore.
- Genentech, South San Francisco, CA, 94080, USA.
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2
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Tay DWP, Tan LL, Heng E, Zulkarnain N, Ching KC, Wibowo M, Chin EJ, Tan ZYQ, Leong CY, Ng VWP, Yang LK, Seow DCS, Lim YW, Koh W, Koduru L, Kanagasundaram Y, Ng SB, Lim YH, Wong FT. Exploring a general multi-pronged activation strategy for natural product discovery in Actinomycetes. Commun Biol 2024; 7:50. [PMID: 38184720 PMCID: PMC10771470 DOI: 10.1038/s42003-023-05648-7] [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: 08/16/2023] [Accepted: 11/29/2023] [Indexed: 01/08/2024] Open
Abstract
Natural products possess significant therapeutic potential but remain underutilized despite advances in genomics and bioinformatics. While there are approaches to activate and upregulate natural product biosynthesis in both native and heterologous microbial strains, a comprehensive strategy to elicit production of natural products as well as a generalizable and efficient method to interrogate diverse native strains collection, remains lacking. Here, we explore a flexible and robust integrase-mediated multi-pronged activation approach to reliably perturb and globally trigger antibiotics production in actinobacteria. Across 54 actinobacterial strains, our approach yielded 124 distinct activator-strain combinations which consistently outperform wild type. Our approach expands accessible metabolite space by nearly two-fold and increases selected metabolite yields by up to >200-fold, enabling discovery of Gram-negative bioactivity in tetramic acid analogs. We envision these findings as a gateway towards a more streamlined, accelerated, and scalable strategy to unlock the full potential of Nature's chemical repertoire.
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Grants
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- NRF-CRP19-2017-05-00 National Research Foundation Singapore (National Research Foundation-Prime Minister's office, Republic of Singapore)
- C211917006 Agency for Science, Technology and Research (A*STAR)
- C233017006 Agency for Science, Technology and Research (A*STAR)
- C211917003 Agency for Science, Technology and Research (A*STAR)
- C211917006 Agency for Science, Technology and Research (A*STAR)
- C233017006 Agency for Science, Technology and Research (A*STAR)
- C211917006 Agency for Science, Technology and Research (A*STAR)
- National Research Foundation Singapore (National Research Foundation-Prime Minister’s office, Republic of Singapore)
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Affiliation(s)
- Dillon W P Tay
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore
| | - Lee Ling Tan
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Republic of Singapore
| | - Elena Heng
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Republic of Singapore
| | - Nadiah Zulkarnain
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Republic of Singapore
| | - Kuan Chieh Ching
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Mario Wibowo
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Elaine Jinfeng Chin
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Zann Yi Qi Tan
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Chung Yan Leong
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Veronica Wee Pin Ng
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Lay Kien Yang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Deborah C S Seow
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Yi Wee Lim
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore
| | - Winston Koh
- Bioinformatics Institute (BII), Agency of Science, Technology and Research (A*STAR), 30 Biopolis Street, #07-01, Matrix, Singapore, 138671, Republic of Singapore
| | - Lokanand Koduru
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Republic of Singapore
| | - Yoganathan Kanagasundaram
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Siew Bee Ng
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, #01-02, Nanos, Singapore, 138669, Republic of Singapore
| | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore.
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Republic of Singapore.
| | - Fong Tian Wong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore.
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Republic of Singapore.
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3
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Peh G, Tay T, Tan LL, Tiong E, Bi J, Goh YL, Ye S, Lin F, Tan CJX, Tan YZ, Wong J, Zhao H, Wong FT, Ang EL, Lim YH. Site-selective chlorination of pyrrolic heterocycles by flavin dependent enzyme PrnC. Commun Chem 2024; 7:7. [PMID: 38182798 PMCID: PMC10770391 DOI: 10.1038/s42004-023-01083-1] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 12/06/2023] [Indexed: 01/07/2024] Open
Abstract
Halogenation of pyrrole requires strong electrophilic reagents and often leads to undesired polyhalogenated products. Biocatalytic halogenation is a highly attractive approach given its chemoselectivity and benign reaction conditions. While there are several reports of enzymatic phenol and indole halogenation in organic synthesis, corresponding reports on enzymatic pyrrole halogenation have been lacking. Here we describe the in vitro functional and structural characterization of PrnC, a flavin-dependent halogenase that can act on free-standing pyrroles. Computational modeling and site mutagenesis studies identified three key residues in the catalytic pocket. A moderate resolution map using single-particle cryogenic electron microscopy reveals PrnC to be a dimer. This native PrnC can halogenate a library of structurally diverse pyrrolic heterocycles in a site-selective manner and be applied in the chemoenzymatic synthesis of a chlorinated analog of the agrochemical fungicide Fludioxonil.
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Affiliation(s)
- GuangRong Peh
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Terence Tay
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Lee Ling Tan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Elaine Tiong
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Jiawu Bi
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Yi Ling Goh
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Suming Ye
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Fu Lin
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Cheryl Jia Xin Tan
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Yong Zi Tan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Disease Intervention Technology Laboratory (DITL), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Joel Wong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
| | - Huimin Zhao
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore
- Department of Chemical and Biomolecular Engineering, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Fong Tian Wong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
| | - Ee Lui Ang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore.
| | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), Singapore, Republic of Singapore.
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Republic of Singapore.
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4
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Tiong E, Koo YS, Bi J, Koduru L, Koh W, Lim YH, Wong FT. Expression and engineering of PET-degrading enzymes from Microbispora, Nonomuraea, and Micromonospora. Appl Environ Microbiol 2023; 89:e0063223. [PMID: 37943056 PMCID: PMC10686063 DOI: 10.1128/aem.00632-23] [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: 04/16/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
IMPORTANCE Mismanagement of PET plastic waste significantly threatens human and environmental health. Together with the relentless increase in plastic production, plastic pollution is an issue of rising concern. In response to this challenge, scientists are investigating eco-friendly approaches, such as bioprocessing and microbial factories, to sustainably manage the growing quantity of plastic waste in our ecosystem. Industrial applicability of enzymes capable of degrading PET is limited by numerous factors, including their scarcity in nature. The objective of this study is to enhance our understanding of this group of enzymes by identifying and characterizing novel enzymes that can facilitate the breakdown of PET waste. This data will expand the enzymatic repertoire and provide valuable insights into the prerequisites for successful PET degradation.
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Grants
- C211917006 Agency for Science, Technology, and Research (A*STAR)
- C211917006 Agency for Science, Technology, and Research (A*STAR)
- C211917003 Agency for Science, Technology, and Research (A*STAR)
- A*STAR Graduate Academy Agency for Science, Technology, and Research (A*STAR)
- C233017006 Agency for Science, Technology, and Research (A*STAR)
- C233017004 Agency for Science, Technology, and Research (A*STAR)
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Affiliation(s)
- Elaine Tiong
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), Proteos, Singapore
| | - Ying Sin Koo
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy, and Environment (ISCE), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Jiawu Bi
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), Proteos, Singapore
| | - Lokanand Koduru
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), Proteos, Singapore
| | - Winston Koh
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy, and Environment (ISCE), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
- Bioinformatics Institute (BII), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
| | - Yee Hwee Lim
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy, and Environment (ISCE), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Fong Tian Wong
- Molecular Engineering Lab, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology, and Research (A*STAR), Proteos, Singapore
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy, and Environment (ISCE), Agency for Science, Technology, and Research (A*STAR), Singapore, Singapore
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5
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Chen Z, Lim YW, Neo JY, Ting Chan RS, Koh LQ, Yuen TY, Lim YH, Johannes CW, Gates ZP. De Novo Sequencing of Synthetic Bis-cysteine Peptide Macrocycles Enabled by "Chemical Linearization" of Compound Mixtures. Anal Chem 2023; 95:14870-14878. [PMID: 37724843 PMCID: PMC10569172 DOI: 10.1021/acs.analchem.3c01742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Accepted: 09/04/2023] [Indexed: 09/21/2023]
Abstract
A "chemical linearization" approach was applied to synthetic peptide macrocycles to enable their de novo sequencing from mixtures using nanoliquid chromatography-tandem mass spectrometry (nLC-MS/MS). This approach─previously applied to individual macrocycles but not to mixtures─involves cleavage of the peptide backbone at a defined position to give a product capable of generating sequence-determining fragment ions. Here, we first established the compatibility of "chemical linearization" by Edman degradation with a prominent macrocycle scaffold based on bis-Cys peptides cross-linked with the m-xylene linker, which are of major significance in therapeutics discovery. Then, using macrocycle libraries of known sequence composition, the ability to recover accurate de novo assignments to linearized products was critically tested using performance metrics unique to mixtures. Significantly, we show that linearized macrocycles can be sequenced with lower recall compared to linear peptides but with similar accuracy, which establishes the potential of using "chemical linearization" with synthetic libraries and selection procedures that yield compound mixtures. Sodiated precursor ions were identified as a significant source of high-scoring but inaccurate assignments, with potential implications for improving automated de novo sequencing more generally.
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Affiliation(s)
- Zhi’ang Chen
- Institute
of Molecular and Cell Biology (IMCB), Agency
for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Yi Wee Lim
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Jin Yong Neo
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Rachel Shu Ting Chan
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Li Quan Koh
- Institute
of Molecular and Cell Biology (IMCB), Agency
for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Tsz Ying Yuen
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Yee Hwee Lim
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
| | - Charles W. Johannes
- Institute
of Molecular and Cell Biology (IMCB), Agency
for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
| | - Zachary P. Gates
- Institute
of Molecular and Cell Biology (IMCB), Agency
for Science, Technology and Research (A*STAR), 61 Biopolis Drive, Proteos, Singapore 138673, Republic of Singapore
- Institute
of Sustainability for Chemicals, Energy and Environment (ISCE), Agency for Science, Technology
and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros, Singapore 138665, Republic
of Singapore
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6
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Tan JH, Chen A, Bi J, Lim YH, Wong FT, Ow DSW. The Engineering, Expression, and Immobilization of Epimerases for D-allulose Production. Int J Mol Sci 2023; 24:12703. [PMID: 37628886 PMCID: PMC10454905 DOI: 10.3390/ijms241612703] [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: 07/10/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
The rare sugar D-allulose is a potential replacement for sucrose with a wide range of health benefits. Conventional production involves the employment of the Izumoring strategy, which utilises D-allulose 3-epimerase (DAEase) or D-psicose 3-epimerase (DPEase) to convert D-fructose into D-allulose. Additionally, the process can also utilise D-tagatose 3-epimerase (DTEase). However, the process is not efficient due to the poor thermotolerance of the enzymes and low conversion rates between the sugars. This review describes three newly identified DAEases that possess desirable properties for the industrial-scale manufacturing of D-allulose. Other methods used to enhance process efficiency include the engineering of DAEases for improved thermotolerance or acid resistance, the utilization of Bacillus subtilis for the biosynthesis of D-allulose, and the immobilization of DAEases to enhance its activity, half-life, and stability. All these research advancements improve the yield of D-allulose, hence closing the gap between the small-scale production and industrial-scale manufacturing of D-allulose.
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Affiliation(s)
- Jin Hao Tan
- Microbial Cell Bioprocessing, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138668, Singapore;
| | - Anqi Chen
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (A*STAR), Singapore 138665, Singapore; (A.C.); (F.T.W.)
| | - Jiawu Bi
- Molecular Engineering Lab, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
- Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117542, Singapore
| | - Yee Hwee Lim
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (A*STAR), Singapore 138665, Singapore; (A.C.); (F.T.W.)
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
| | - Fong Tian Wong
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment, Agency for Science, Technology and Research (A*STAR), Singapore 138665, Singapore; (A.C.); (F.T.W.)
- Molecular Engineering Lab, Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore;
| | - Dave Siak-Wei Ow
- Microbial Cell Bioprocessing, Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore 138668, Singapore;
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7
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Peh G, Gunawan GA, Tay T, Tiong E, Tan LL, Jiang S, Goh YL, Ye S, Wong J, Brown CJ, Zhao H, Ang EL, Wong FT, Lim YH. Further Characterization of Fungal Halogenase RadH and Its Homologs. Biomolecules 2023; 13:1081. [PMID: 37509117 PMCID: PMC10377541 DOI: 10.3390/biom13071081] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/27/2023] [Accepted: 06/29/2023] [Indexed: 07/30/2023] Open
Abstract
RadH is one of the flavin-dependent halogenases that has previously exhibited promising catalytic activity towards hydroxycoumarin, hydroxyisoquinoline, and phenolic derivatives. Here, we evaluated new functional homologs of RadH and expanded its specificities for the halogenation of non-tryptophan-derived, heterocyclic scaffolds. Our investigation revealed that RadH could effectively halogenate hydroxyquinoline and hydroxybenzothiophene. Assay optimization studies revealed the need to balance the various co-factor concentrations and where a GDHi co-factor recycling system most significantly improves the conversion and efficiency of the reaction. A crystal structure of RadH was also obtained with a resolution of 2.4 Å, and docking studies were conducted to pinpoint the binding and catalytic sites for substrates.
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Affiliation(s)
- GuangRong Peh
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Gregory A Gunawan
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Dr, Proteos #07-01, Singapore 138673, Singapore
| | - Terence Tay
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-02, Singapore 138669, Singapore
| | - Elaine Tiong
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Dr, Proteos #07-01, Singapore 138673, Singapore
| | - Lee Ling Tan
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Dr, Proteos #07-01, Singapore 138673, Singapore
| | - Shimin Jiang
- Disease Intervention Technology Laboratory, Institute of Molecular and Cellular Biology, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Neuros/Immunos #06-04/05, Singapore 138648, Singapore
| | - Yi Ling Goh
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Suming Ye
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Joel Wong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Christopher J Brown
- Disease Intervention Technology Laboratory, Institute of Molecular and Cellular Biology, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Neuros/Immunos #06-04/05, Singapore 138648, Singapore
| | - Huimin Zhao
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-02, Singapore 138669, Singapore
- Department of Chemical and Biomolecular Engineering, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ee Lui Ang
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-02, Singapore 138669, Singapore
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
| | - Fong Tian Wong
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
- Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Dr, Proteos #07-01, Singapore 138673, Singapore
| | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore 117597, Singapore
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8
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Tay DWP, Yeo NZX, Adaikkappan K, Lim YH, Ang SJ. 67 million natural product-like compound database generated via molecular language processing. Sci Data 2023; 10:296. [PMID: 37208372 DOI: 10.1038/s41597-023-02207-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 04/21/2023] [Indexed: 05/21/2023] Open
Abstract
Natural products are a rich resource of bioactive compounds for valuable applications across multiple fields such as food, agriculture, and medicine. For natural product discovery, high throughput in silico screening offers a cost-effective alternative to traditional resource-heavy assay-guided exploration of structurally novel chemical space. In this data descriptor, we report a characterized database of 67,064,204 natural product-like molecules generated using a recurrent neural network trained on known natural products, demonstrating a significant 165-fold expansion in library size over the approximately 400,000 known natural products. This study highlights the potential of using deep generative models to explore novel natural product chemical space for high throughput in silico discovery.
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Affiliation(s)
- Dillon W P Tay
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore.
| | - Naythan Z X Yeo
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore
- Hwa Chong Institution, 661 Bukit Timah Road, Singapore, 269734, Republic of Singapore
| | - Krishnan Adaikkappan
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore
- National Junior College, 37 Hillcrest Road, Singapore, 288913, Republic of Singapore
| | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore
- Synthetic Biology Translational Research Program, Yong Loo Lin School of Medicine, National University of Singapore, 10 Medical Drive, Singapore, 117597, Republic of Singapore
| | - Shi Jun Ang
- Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, #07-01 Neuros Building, Singapore, 138665, Republic of Singapore.
- Institute of High Performance Computing (IHPC), Agency for Science, Technology and Research (A*STAR), 1 Fusionopolis Way, #16-16 Connexis, Singapore, 138632, Republic of Singapore.
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9
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Heng E, Lim YW, Leong CY, Ng VWP, Ng SB, Lim YH, Wong FT. Enhancing armeniaspirols production through multi-level engineering of a native Streptomyces producer. Microb Cell Fact 2023; 22:84. [PMID: 37118806 PMCID: PMC10142417 DOI: 10.1186/s12934-023-02092-4] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 04/11/2023] [Indexed: 04/30/2023] Open
Abstract
BACKGROUND Nature has provided unique molecular scaffolds for applications including therapeutics, agriculture, and food. Due to differences in ecological environments and laboratory conditions, engineering is often necessary to uncover and utilize the chemical diversity. Although we can efficiently activate and mine these often complex 3D molecules, sufficient production of target molecules for further engineering and application remain a considerable bottleneck. An example of these bioactive scaffolds is armeniaspirols, which are potent polyketide antibiotics against gram-positive pathogens and multi-resistance gram-negative Helicobacter pylori. Here, we examine the upregulation of armeniaspirols in an alternative Streptomyces producer, Streptomyces sp. A793. RESULTS Through an incidental observation of enhanced yields with the removal of a competing polyketide cluster, we observed seven-fold improvement in armeniaspirol production. To further investigate the improvement of armeniaspirol production, we examine upregulation of armeniaspirols through engineering of biosynthetic pathways and primary metabolism; including perturbation of genes in biosynthetic gene clusters and regulation of triacylglycerols pool. CONCLUSION With either overexpression of extender unit pathway or late-stage N-methylation, or the deletion of a competing polyketide cluster, we can achieve seven-fold to forty nine-fold upregulation of armeniaspirol production. The most significant upregulation was achieved by expression of heterologous fatty acyl-CoA synthase, where we observed not only a ninety seven-fold increase in production yields compared to wild type, but also an increase in the diversity of observed armeniaspirol intermediates and analogs.
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Affiliation(s)
- Elena Heng
- Molecular Engineering Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Singapore
| | - Yi Wee Lim
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros, #07-01, Singapore, 138665, Singapore
| | - Chung Yan Leong
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Level 2, Nanos, Singapore, 138669, Singapore
| | - Veronica W P Ng
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Level 2, Nanos, Singapore, 138669, Singapore
| | - Siew Bee Ng
- Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Level 2, Nanos, Singapore, 138669, Singapore
| | - Yee Hwee Lim
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros, #07-01, Singapore, 138665, Singapore.
| | - Fong Tian Wong
- Molecular Engineering Laboratory, Institute of Molecular and Cell Biology (IMCB), Agency for Science, Technology and Research (A*STAR), 61 Biopolis Drive, #07-06, Proteos, Singapore, 138673, Singapore.
- Chemical Biotechnology and Biocatalysis, Institute of Sustainability for Chemicals, Energy and Environment (ISCE2), Agency for Science, Technology and Research (A*STAR), 8 Biomedical Grove, Neuros, #07-01, Singapore, 138665, Singapore.
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10
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Teoh SE, Tan EWX, Teo YN, Basker G, Teo YH, Chai P, Wong RCC, Yip JWL, Kuntjoro I, Lim YH, Poh KK, Yeo TC, Kong WKF, Sia CH. Effects of medical therapy, transcatheter intervention, and surgery on outcomes of patients with functional mitral regurgitation: a systematic review and network meta-analysis. Eur Heart J 2023. [DOI: 10.1093/eurheartj/ehac779.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Public Institution(s). Main funding source(s): Ching-Hui Sia was supported by the National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme.
Background
Functional mitral regurgitation (FMR) is the most common valvular heart disease worldwide. Despite recent major trials, the relative efficacy between medical therapy, transcatheter intervention, and surgery for the treatment of FMR remains poorly understood.
Purpose
We performed a systematic review and network meta-analysis of all published randomised controlled trials (RCTs) and observational studies to compare the efficacy between medical therapy, transcatheter intervention, and surgery on the clinical outcomes of patients with FMR.
Methods
Four electronic databases (PubMed, EMBASE, SCOPUS, and the Cochrane Library) were searched from inception to March 13, 2022, for studies reporting clinical outcomes in patients with FMR and comparing the efficacy between either medical therapy, transcatheter intervention, or surgery. Frequentist network meta-analysis models were utilised to summarise the studies. This study was registered in the International Prospective Register of Systematic Reviews.
Results
10 articles were included in the analysis, comprising a combined cohort of 1,981 patients. Network meta-analysis demonstrated that compared to medical therapy, transcatheter intervention achieved a lower relative risk in the composites of all-cause mortality (risk ratio [RR]: 0.43; 95% confidence interval [CI] 0.22-0.82) and mitral regurgitation (MR) severity grade ≥3+ (RR: 0.06; 95% CI 0.01-0.42). Compared to surgery, transcatheter intervention achieved a lower relative risk in the composites of cardiovascular death (RR: 0.36; 95% CI 0.17-0.75) and MR severity grade ≥3+ (RR: 0.25; 95% CI 0.09-0.70) and higher relative risk in the composite of heart failure hospitalisation (RR: 2.94; 95% CI 1.26-6.82). Compared to medical therapy, surgery achieved a higher relative risk in the composite of cardiovascular death (RR: 2.54; 95% CI 1.18-5.47) and lower relative risks in the composites of all-cause mortality (RR: 0.56; 95% CI 0.34-0.91) and heart failure hospitalisation (RR: 0.28; 95% CI 0.13-0.61).
Conclusion
Medical therapy, transcatheter intervention, and surgery in patients with FMR displayed differing effects on the various clinical outcomes. Further head-to-head trials are required to better understand the optimal treatment modality in this population.
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Affiliation(s)
- S E Teoh
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - E W X Tan
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y N Teo
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - G Basker
- National University of Singapore, Yong Loo Lin School of Medicine , Singapore , Singapore
| | - Y H Teo
- National University of Singapore, Department of Medicine , Singapore , Singapore
| | - P Chai
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - R C C Wong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - J W L Yip
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - I Kuntjoro
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - Y H Lim
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - K K Poh
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - T C Yeo
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - W K F Kong
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
| | - C H Sia
- National University Heart Centre, Department of Cardiology , Singapore , Singapore
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11
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Cheong CB, Peh G, Wei Y, T R, Ang EL, Zhao H, Zhang C, Lim YH. A Spirobicyclo[3.1.0]Terpene from the Investigation of Sesquiterpene Synthases from Lactarius deliciosus. ACS Chem Biol 2023; 18:134-140. [PMID: 36594743 DOI: 10.1021/acschembio.2c00760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Milk cap mushrooms in the genus Lactarius are known to produce a wide variety of terpene natural products. However, their repertoire of terpene biosynthetic enzymes has not been fully explored. In this study, several candidate sesquiterpene synthases were identified from the genome of the saffron milk cap mushroom L. deliciosus and expressed in a sesquiterpene-overproducing Escherichia coli strain. In addition to enzymes that produce several known terpenes, we identified an enzyme belonging to a previously unknown clade of sesquiterpene synthases that produces a terpene with a unique spiro-tricyclic scaffold. These findings add to the rich diversity of terpene scaffolds and mushroom terpene synthases and are valuable for biotechnological applications in producing these terpenoids.
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Affiliation(s)
- Choon Boon Cheong
- Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, Singapore 138665, Singapore
| | - GuangRong Peh
- Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, Singapore 138665, Singapore
| | - Yifeng Wei
- Singapore Institute of Food and Biotechnology Innovation, A*STAR, Singapore 138669, Singapore
| | - Rehka T
- Singapore Institute of Food and Biotechnology Innovation, A*STAR, Singapore 138669, Singapore
| | - Ee Lui Ang
- Singapore Institute of Food and Biotechnology Innovation, A*STAR, Singapore 138669, Singapore
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Congqiang Zhang
- Singapore Institute of Food and Biotechnology Innovation, A*STAR, Singapore 138669, Singapore
| | - Yee Hwee Lim
- Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, Singapore 138665, Singapore
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12
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Barat V, Chen A, Lim YH. An improved stereodivergent and practical synthesis of α- and β-pseudouridine. REACT CHEM ENG 2023. [DOI: 10.1039/d2re00381c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
An improved stereodivergent and practical synthesis of both α- and β-pseudouridines have been achieved from a common intermediate. This practical approach features a highly diastereoselective Grignard reaction to the inexpensive...
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13
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Cousins DL, Lim YH, Harrity JPA. A Mild and Regioselective Route to Fluoroalkyl Aromatic Compounds via Directed Cycloaddition Reactions. J Org Chem 2022; 87:9764-9768. [PMID: 35802868 PMCID: PMC9365296 DOI: 10.1021/acs.joc.2c00800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
![]()
The synthesis of perfluoroalkyl-substituted (hetero)arenes
by benzannulation
strategies is complementary to ring functionalization approaches as
it obviates the need for pre-existing functionality and innate regiocontrol.
We report a mild and regiospecific boron-directed benzannulation method
as a vehicle for accessing a range of perfluoroalkyl-substituted (hetero)aromatic
building blocks that can be readily elaborated through established
C–B bond functionalization processes.
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Affiliation(s)
- David L Cousins
- Department of Chemistry, University of Sheffield, Sheffield S3 7HF, U.K.,Organic and Biomolecular Chemistry, Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, 8 Biomedical Grove, Neuros, #07-01, Singapore 138665, Singapore
| | - Yee Hwee Lim
- Organic and Biomolecular Chemistry, Institute of Sustainability for Chemicals, Energy and Environment, A*STAR, 8 Biomedical Grove, Neuros, #07-01, Singapore 138665, Singapore
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14
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Bergmann ML, Andersen ZJ, Amini H, Khan J, Lim YH, Loft S, Mehta A, Westendorp RG, Cole-Hunter T. Ultrafine particle exposure for bicycle commutes in rush and non-rush hour traffic: A repeated measures study in Copenhagen, Denmark. Environ Pollut 2022; 294:118631. [PMID: 34871646 DOI: 10.1016/j.envpol.2021.118631] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 06/13/2023]
Abstract
Ultrafine particles (UFP), harmful to human health, are emitted at high levels from motorized traffic. Bicycle commuting is increasingly encouraged to reduce traffic emissions and increase physical activity, but higher breathing rates increase inhaled UFP concentrations while in traffic. We assessed exposure to UFP while cycling along a fixed 8.5 km inner-city route in Copenhagen, on weekdays over six weeks (from September to October 2020), during morning and afternoon rush-hour, as well as morning non-rush-hour, traffic time periods starting from 07:45, 15:45, and 09:45 h, respectively. Continuous measurements were made (each second) of particle number concentration (PNC) and location. PNC levels were summarized and compared across time periods. We used generalized additive models to adjust for meteorological factors, weekdays and trends. A total of 61 laps were completed, during 28 days (∼20 per time period). Overall mean PNC was 18,149 pt/cm3 (range 256-999,560 pt/cm3) with no significant difference between morning rush-hour (18003 pt/cm3), afternoon rush-hour (17560 pt/cm3) and late morning commute (17560 pt/cm3) [p = 0.85]. There was substantial spatial variation of UFP exposure along the route with highest PNC levels measured at traffic intersections (∼38,000-42000 pt/cm3), multiple lane roads (∼38,000-40000 pt/cm3) and construction sites (∼44,000-51000 pt/cm3), while lowest levels were measured at smaller streets, areas with open built environment (∼12,000 pt/cm3), as well as at a bus-only zone (∼15,000 pt/cm3). UFP exposure in inner-city Copenhagen did not differ substantially when bicycling in either rush-hour or non-rush-hour, or morning or afternoon, traffic time periods. UFP exposure varied substantially spatially, with highest concentrations around intersections, multiple lane roads, and construction sites. This suggests that exposure to UFP is not necessarily reduced by avoiding rush-hours, but by avoiding sources of pollution along the bicycling route.
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Affiliation(s)
- M L Bergmann
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
| | - Z J Andersen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - H Amini
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - J Khan
- Atmospheric Modelling Research Group, Department of Environmental Science, Aarhus University, Roskilde, Denmark; Danish Big Data Centre for Environment and Health (BERTHA), Aarhus University, Roskilde, Denmark
| | - Y H Lim
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - S Loft
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - A Mehta
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; Statistics Denmark, Copenhagen, Denmark
| | - R G Westendorp
- Department of Public Health and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - T Cole-Hunter
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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15
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Bergmann ML, Andersen ZJ, Amini H, Ellermann T, Hertel O, Lim YH, Loft S, Mehta A, Westendorp RG, Cole-Hunter T. Exposure to ultrafine particles while walking or bicycling during COVID-19 closures: A repeated measures study in Copenhagen, Denmark. Sci Total Environ 2021; 791:148301. [PMID: 34412377 PMCID: PMC8178061 DOI: 10.1016/j.scitotenv.2021.148301] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 05/27/2021] [Accepted: 06/01/2021] [Indexed: 05/15/2023]
Abstract
Ultrafine particles (UFP; particulate matter <0.1 μm diameter) emitted from motorized traffic may be highly detrimental to health. Active mobility (walking, bicycling) is increasingly encouraged as a way to reduce traffic congestion and increase physical activity levels. However, it has raised concerns of increased exposure to UFP, due to increased breathing rates in traffic microenvironments, immediately close to their source. The recent Coronavirus Disease 2019 (COVID-19) societal closures reduced commuting needs, allowing a natural experiment to estimate contributions from motorized traffic to UFP exposure while walking or bicycling. From late-March to mid-July 2020, UFP was repeatedly measured while walking or bicycling, capturing local COVID-19 closure ('Phase 0') and subsequent phased re-opening ('Phase 1', '2', '2.1' & '3'). A DiSCmini continuously measured particle number concentration (PNC) in the walker/bicyclist's breathing zone. PNC while walking or bicycling was compared across phased re-openings, and the effect of ambient temperature, wind speed and direction was determined using regression models. Approximately 40 repeated 20-minute walking and bicycling laps were made over 4 months during societal re-opening phases related to the COVID-19 pandemic (late-March to mid-July 2020) in Copenhagen. Highest median PNC exposure of both walking (13,170 pt/cm3, standard deviation (SD): 3560 pt/cm3) and bicycling (21,477 pt/cm3, SD: 8964) was seen during societal closures (Phase 0) and decreased to 5367 pt/cm3 (SD: 2949) and 8714 pt/cm3 (SD: 4309) in Phase 3 of re-opening. These reductions in PNC were mainly explained by meteorological conditions, with most of the deviation explained by wind speed (14-22%) and temperature (10-13%). Highest PNC was observed along major roads and intersections. In conclusion, we observed decreases in UFP exposure while walking and bicycling during societal re-opening phases related to the COVID-19 pandemic, due largely to meteorological factors (e.g., wind speed and temperature) and seasonal variations in UFP levels.
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Affiliation(s)
- M L Bergmann
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
| | - Z J Andersen
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - H Amini
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - T Ellermann
- Department of Environmental Science, Aarhus University, Roskilde, Denmark
| | - O Hertel
- Department of Bioscience, Aarhus University, Roskilde, Denmark
| | - Y H Lim
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - S Loft
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - A Mehta
- Section of Epidemiology, Department of Public Health, University of Copenhagen, Copenhagen, Denmark; Statistics Denmark, Copenhagen, Denmark
| | - R G Westendorp
- Department of Public Health and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - T Cole-Hunter
- Section of Environmental Health, Department of Public Health, University of Copenhagen, Copenhagen, Denmark
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16
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Cousins DL, Fricero P, Kopf KPM, McColl EJ, Czechtizky W, Lim YH, Harrity JPA. Pyrimidin‐6‐yl Trifluoroborate Salts as Versatile Templates for Heterocycle Synthesis. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- David L. Cousins
- Department of Chemistry University of Sheffield Sheffield S3 7HF UK
| | - Prisca Fricero
- Department of Chemistry University of Sheffield Sheffield S3 7HF UK
| | - Kenji P. M. Kopf
- Department of Chemistry University of Sheffield Sheffield S3 7HF UK
| | - Elliot J. McColl
- Department of Chemistry University of Sheffield Sheffield S3 7HF UK
| | - Werngard Czechtizky
- Integrated Drug discovery R&D Sanofi Aventis (Deutschland) GmbH Industriepark Höchst 65926 Frankfurt am Main Germany
- Present address: Department of Medicinal Chemistry Research and Early Development Respiratory & Immunology BioPharmaceuticals R&D AstraZeneca Pepparedsleden 1 43183 Mölndal Sweden
| | - Yee Hwee Lim
- Functional Molecules & Polymers Institute of Chemical and Engineering Sciences A*STAR, Biopolis Singapore Singapore
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17
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Cousins DL, Fricero P, Kopf KPM, McColl EJ, Czechtizky W, Lim YH, Harrity JPA. Pyrimidin-6-yl Trifluoroborate Salts as Versatile Templates for Heterocycle Synthesis. Angew Chem Int Ed Engl 2021; 60:9412-9415. [PMID: 33570831 PMCID: PMC8252621 DOI: 10.1002/anie.202101297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [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: 01/27/2021] [Indexed: 12/29/2022]
Abstract
We report a novel and general method to access a highly under-studied privileged scaffold-pyrimidines bearing a trifluoroborate at C4, and highlight the broad utility of these intermediates in a rich array of downstream functionalization reactions. This chemistry is underpinned by the unique features of the trifluoroborate group; its robustness provides an opportunity to carry out chemoselective reactions at other positions on the pyrimidine while providing a pathway for elaboration at the C-B bond when suitably activated.
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Affiliation(s)
- David L Cousins
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Prisca Fricero
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Kenji P M Kopf
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Elliot J McColl
- Department of Chemistry, University of Sheffield, Sheffield, S3 7HF, UK
| | - Werngard Czechtizky
- Integrated Drug discovery, R&D, Sanofi Aventis (Deutschland) GmbH, Industriepark Höchst, 65926, Frankfurt am Main, Germany
- Present address: Department of Medicinal Chemistry, Research and Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Pepparedsleden 1, 43183, Mölndal, Sweden
| | - Yee Hwee Lim
- Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore, Singapore
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Aksanoglu E, Lim YH, Bryce RA. Direct Deoxydehydration of Cyclic trans-Diol Substrates: An Experimental and Computational Study of the Reaction Mechanism of Vanadium(V)-based Catalysis*. ChemSusChem 2021; 14:1545-1553. [PMID: 33465299 PMCID: PMC8048994 DOI: 10.1002/cssc.202002594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/11/2021] [Indexed: 06/12/2023]
Abstract
The deoxydehydration of carbohydrates represents a key target to leverage renewable biomass resources chemically. Using a vanadium(V)-based catalyst, it was possible to directly deoxydehydrate cyclic trans-diol substrates. Accompanying mechanistic characterisation of this process by density functional calculations pointed to an energetically tractable route for deoxydehydration of cyclic trans-diol substrates involving stepwise cleavage of the diol C-O bonds via the triplet state; experimentally, this was supported by light dependence of the reaction. Calculations also indicated that cyclic cis-diols and a linear diol substrate could additionally proceed by a concerted singlet DODH mechanism. This work potentially opens a new and cost-effective way to efficiently convert carbohydrates of trans-diol stereochemistry into alkenes.
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Affiliation(s)
- Ebru Aksanoglu
- Division of Pharmacy and Optometry, School of Health SciencesManchester Academic Health Sciences CentreUniversity of ManchesterOxford RoadManchesterM13 9PLUK
- Functional Molecules & PolymersInstitute of Chemical and Engineering Sciences8 Biomedical Grove, #07-01/02Singapore138665Singapore
| | - Yee Hwee Lim
- Functional Molecules & PolymersInstitute of Chemical and Engineering Sciences8 Biomedical Grove, #07-01/02Singapore138665Singapore
| | - Richard A. Bryce
- Division of Pharmacy and Optometry, School of Health SciencesManchester Academic Health Sciences CentreUniversity of ManchesterOxford RoadManchesterM13 9PLUK
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Yeo WL, Heng E, Tan LL, Lim YW, Ching KC, Tsai DJ, Jhang YW, Lauderdale TL, Shia KS, Zhao H, Ang EL, Zhang MM, Lim YH, Wong FT. Biosynthetic engineering of the antifungal, anti-MRSA auroramycin. Microb Cell Fact 2020; 19:3. [PMID: 31906943 PMCID: PMC6943886 DOI: 10.1186/s12934-019-1274-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 11/06/2019] [Accepted: 12/21/2019] [Indexed: 12/12/2022] Open
Abstract
Using an established CRISPR-Cas mediated genome editing technique for streptomycetes, we explored the combinatorial biosynthesis potential of the auroramycin biosynthetic gene cluster in Streptomyces roseosporous. Auroramycin is a potent anti-MRSA polyene macrolactam. In addition, auroramycin has antifungal activities, which is unique among structurally similar polyene macrolactams, such as incednine and silvalactam. In this work, we employed different engineering strategies to target glycosylation and acylation biosynthetic machineries within its recently elucidated biosynthetic pathway. Auroramycin analogs with variations in C-, N- methylation, hydroxylation and extender units incorporation were produced and characterized. By comparing the bioactivity profiles of five of these analogs, we determined that unique disaccharide motif of auroramycin is essential for its antimicrobial bioactivity. We further demonstrated that C-methylation of the 3, 5-epi-lemonose unit, which is unique among structurally similar polyene macrolactams, is key to its antifungal activity.
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Affiliation(s)
- Wan Lin Yeo
- Metabolic Engineering, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore
| | - Elena Heng
- Molecular Engineering Laboratory, Institute of Bioengineering and Nanotechnology, A*STAR, Biopolis, Singapore
| | - Lee Ling Tan
- Molecular Engineering Laboratory, Institute of Bioengineering and Nanotechnology, A*STAR, Biopolis, Singapore
| | - Yi Wee Lim
- Integrated Bio & Organic Chemistry, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore
| | - Kuan Chieh Ching
- Integrated Bio & Organic Chemistry, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore
| | - De-Juin Tsai
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes (NHRI), Zhunan, Miaoli, Taiwan
| | - Yi Wun Jhang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes (NHRI), Zhunan, Miaoli, Taiwan
| | - Tsai-Ling Lauderdale
- National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes (NHRI), Zhunan, Miaoli, Taiwan
| | - Kak-Shan Shia
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes (NHRI), Zhunan, Miaoli, Taiwan
| | - Huimin Zhao
- Departments of Chemical and Biomolecular Engineering, Chemistry, Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ee Lui Ang
- Metabolic Engineering, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore
| | - Mingzi M Zhang
- Metabolic Engineering, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore.,Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli, Taiwan
| | - Yee Hwee Lim
- Integrated Bio & Organic Chemistry, Functional Molecules & Polymers, Institute of Chemical and Engineering Sciences, A*STAR, Biopolis, Singapore.
| | - Fong T Wong
- Molecular Engineering Laboratory, Institute of Bioengineering and Nanotechnology, A*STAR, Biopolis, Singapore.
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Lee Y, Park HC, Shin JH, Lim YH, Park JK, Shin J, Kim KS, Kim BK. P5298Influence of the changes in body fat on all-cause and cardiovascular mortality in a general population: a report from Ansan-Ansung cohort in the Korean genome environment study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Paradoxical beneficial effects of obesity on all-cause and cardiovascular mortality have been reported in multiple cohort studies based on patients with cardiovascular disease as well as general populations. However, the association between the presence of obesity at baseline and the better survival rates could not be directly interpreted into the beneficial effect of gain in obesity or fatness on the mortality, which makes it difficult to provide any recommendation for the management of obesity. Therefore, we investigated the influence of the changes in body fat on all-cause and cardiovascular mortality in a general population.
Methods
A population-based cohort study has been conducted for 12 years (from 2001 to 2012). A total of 5,259 subjects in whom body compositions using a bio-impedance method were measured at least 2 times during the observational period were included. The causes of death was identified from the nation-wide database in KOSTAT. I20-I82 and R99 in the International Classification of Disease-10 codes were defined as a cardiovascular death. The subjects were evenly divided into 3 groups by the percentages of the changes in body fat (Δ%BF; decreased [Δ%BF <0.0%] vs. increased [Δ%BF 0.0–13.7%] vs. highly increased [Δ%BF ≥13.7%]). Inverse probability of treatment weighting was applied to balance the covariate differences among the groups.
Results
The age was 51.2±8.5 years and 51.6% was male. Median observation duration was 163 (the interquartile range: 157–168) months. The all-cause death and cardiovascular death occurred most frequently in the decreased Δ%BF group and least frequent in the highly increased Δ%BF group in both unweighted and weighted cohort. Multivariate Cox proportional hazard models showed that the risk of all-cause death was lower in the increased and highly increased Δ%BF groups (hazard ratio [HR] 0.61 [0.47–0.80] and 0.24 [0.17–0.34], respectively) and the risk of cardiovascular death was lower in the highly increased Δ%BF group (HR 0.20 [0.08–0.48]), compared to those in the decreased Δ%BF group after adjustment for all covariates including physical activities and the changes in muscle mass. The risk of all-cause death and cardiovascular death linearly decreased with increasing Δ%BF (HR 0.72 [0.67–0.77] and 0.70 [0.60–0.82], respectively).
Conclusion
The increase in body fat is associated with a lower risk of all-cause death and cardiovascular death in a middle-age general population, independently with physical activities and the changes in muscle mass.
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Affiliation(s)
- Y Lee
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - H C Park
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - J H Shin
- Hanyang University Kuri Hospital, Department of cardiology, Guri, Korea (Republic of)
| | - Y H Lim
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - J K Park
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - J Shin
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - K S Kim
- Hanyang University, Division of Cardiology, Department of internal medicine, Seoul, Korea (Republic of)
| | - B K Kim
- Sung Ae Hospital, Department of Cardiology, Seoul, Korea (Republic of)
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Abstract
Abstract
Purpose
Patients with diabetes mellitus have an elevated risk of atrial fibrillation (AF). However, whether insulin resistance may elevate risk of AF incidence in non-diabetic is inconsistent. The aim of our study was to verify the association between insulin resistance and incidence of AF in non-diabetics.
Methods
We evaluated population-based cohorts embedded in the Korean Genome Epidemiology Study. Insulin resistance was expressed as Homeostasis Model Assessment for Insulin resistance (HOMA-IR). Baseline data including HOMA-IR and electrocardiography (ECG) were obtained at 2001. Subsequent biennial ECG was performed for identification of AF until 2016.
Results
Among the 8220 participants (46.8% male; median age 49 years), 25 participants had AF (0.3%) at baseline and 101 participants developed AF (1.2%) during follow up of 12 years. In multivariate Cox regression analysis, high HOMA-IR (≥1.4) was significantly associated with incident AF compared with low HOMA-IR (<1.40) (adjusted hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.3–3.0). In subgroup analysis, these association was consistent regardless of obesity (BMI<25; adjust HR 1.8, 95% CI 1.1–3.0, BMI≥25; adjust HR 2.3, 95% CI 1.3–4.0)
Subgroup analysis
Conclusion
Based on prospective cohort study, insulin resistance (HOMA-IR) was associated with AF independently of obesity in non-diabetics.
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Affiliation(s)
- J K Park
- Hanyang University, Seoul, Korea (Republic of)
| | - J H Park
- Hanyang University, Seoul, Korea (Republic of)
| | - Y G Lee
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea (Republic of)
| | - J H Shin
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea (Republic of)
| | - Y H Lim
- Hanyang University, Seoul, Korea (Republic of)
| | - R Heo
- Hanyang University, Seoul, Korea (Republic of)
| | - J Shin
- Hanyang University, Seoul, Korea (Republic of)
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Wong JH, Alfatah M, Kong KW, Hoon S, Yeo WL, Ching KC, Goh CJH, Zhang MM, Lim YH, Wong FT, Arumugam P. Correction: Chemogenomic profiling in yeast reveals antifungal mode-of-action of polyene macrolactam auroramycin. PLoS One 2019; 14:e0221074. [PMID: 31393972 PMCID: PMC6687108 DOI: 10.1371/journal.pone.0221074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Wong JH, Alfatah M, Kong KW, Hoon S, Yeo WL, Ching KC, Jie Hui Goh C, Zhang MM, Lim YH, Wong FT, Arumugam P. Chemogenomic profiling in yeast reveals antifungal mode-of-action of polyene macrolactam auroramycin. PLoS One 2019; 14:e0218189. [PMID: 31181115 PMCID: PMC6557514 DOI: 10.1371/journal.pone.0218189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/28/2019] [Indexed: 12/23/2022] Open
Abstract
In this study, we report antifungal activity of auroramycin against Candida albicans, Candida tropicalis, and Cryptococcus neoformans. Auroramycin, a potent antimicrobial doubly glycosylated 24-membered polyene macrolactam, was previously isolated and characterized, following CRISPR-Cas9 mediated activation of a silent polyketide synthase biosynthetic gene cluster in Streptomyces rosesporous NRRL 15998. Chemogenomic profiling of auroramycin in yeast has linked its antifungal bioactivity to vacuolar transport and membrane organization. This was verified by disruption of vacuolar structure and membrane integrity of yeast cells with auroramycin treatment. Addition of salt but not sorbitol to the medium rescued the growth of auroramycin-treated yeast cells suggesting that auroramycin causes ionic stress. Furthermore, auroramycin caused hyperpolarization of the yeast plasma membrane and displayed a synergistic interaction with cationic hygromycin. Our data strongly suggest that auroramycin inhibits yeast cells by causing leakage of cations from the cytoplasm. Thus, auroramycin’s mode-of-action is distinct from known antifungal polyenes, reinforcing the importance of natural products in the discovery of new anti-infectives.
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Affiliation(s)
| | | | | | - Shawn Hoon
- Molecular Engineering Laboratory, Singapore
| | - Wan Lin Yeo
- Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, Singapore
| | - Kuan Chieh Ching
- Organic Chemistry, Institute of Chemical and Engineering Sciences, Singapore
| | | | - Mingzi M Zhang
- Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, Singapore
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences, Singapore
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Yeo WL, Heng E, Tan LL, Lim YW, Lim YH, Hoon S, Zhao H, Zhang MM, Wong FT. Characterization of Cas proteins for CRISPR-Cas editing in streptomycetes. Biotechnol Bioeng 2019; 116:2330-2338. [PMID: 31090220 DOI: 10.1002/bit.27021] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/02/2019] [Accepted: 05/09/2019] [Indexed: 12/26/2022]
Abstract
Application of the well-characterized Streptococcus pyogenes CRISPR-Cas9 system in actinomycetes streptomycetes has enabled high-efficiency multiplex genome editing and CRISPRi-mediated transcriptional regulation in these prolific bioactive metabolite producers. Nonetheless, SpCas9 has its limitations and can be ineffective depending on the strains and target sites. Here, we built and tested alternative CRISPR-Cas constructs based on the standalone pCRISPomyces-2 editing plasmid. We showed that Streptococcus thermophilus CRISPR1 Cas9 (sth1Cas9), Staphylococcus aureus Cas9 (saCas9), and Francisella tularensis subsp. novicida U112 Cpf1 (fnCpf1) are functional in multiple streptomycetes, enabling efficient homology-directed repair-mediated knock-in and deletion. In strains where spCas9 was nonfunctional, these alternative Cas systems enabled precise genomic modifications within biosynthetic gene clusters for the discovery, production, and diversification of natural products. These additional Cas proteins provide us with the versatility to overcome the limitations of individual CRISPR-Cas systems for genome editing and transcriptional regulation of these industrially important bacteria.
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Affiliation(s)
- Wan Lin Yeo
- Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, A*STAR, Singapore, Singapore
| | - Elena Heng
- Molecular Engineering Laboratory, Biomedical Institutes of Sciences, A*STAR, Singapore, Singapore
| | - Lee Ling Tan
- Molecular Engineering Laboratory, Biomedical Institutes of Sciences, A*STAR, Singapore, Singapore
| | - Yi Wee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences, A*STAR, Singapore, Singapore
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences, A*STAR, Singapore, Singapore
| | - Shawn Hoon
- Molecular Engineering Laboratory, Biomedical Institutes of Sciences, A*STAR, Singapore, Singapore
| | - Huimin Zhao
- Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, A*STAR, Singapore, Singapore
- Department of Chemical and Biomolecular Engineering, University of Illinois, Urbana-Champaign, Illinois, United States
- Department of Chemistry, University of Illinois, Urbana-Champaign, Illinois, United States
- Department of Biochemistry, University of Illinois, Urbana-Champaign, Illinois, United States
| | - Mingzi M Zhang
- Metabolic Engineering Research Laboratory, Institute of Chemical and Engineering Sciences, A*STAR, Singapore, Singapore
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Taiwan, R.O.C
| | - Fong Tian Wong
- Molecular Engineering Laboratory, Biomedical Institutes of Sciences, A*STAR, Singapore, Singapore
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Park JK, Choi YW, Kim BS, Chang KS, Lee YG, Shin JH, Lim YH, Park HC, Shin J. P1880Independent effect of physical activity and resting heart rate on incidence of atrial fibrillation in general population. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J K Park
- Hanyang University, Seoul, Korea Republic of
| | - Y W Choi
- Hanyang University, Seoul, Korea Republic of
| | - B S Kim
- Hanyang University, Seoul, Korea Republic of
| | - K S Chang
- Hanyang University, Seoul, Korea Republic of
| | - Y G Lee
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - J H Shin
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - Y H Lim
- Hanyang University, Seoul, Korea Republic of
| | - H C Park
- Hanyang University Kuri Hospital, Cardiology, Guri, Korea Republic of
| | - J Shin
- Hanyang University, Seoul, Korea Republic of
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Lee Y, Park JK, Lim YH, Shin JH, Park HC, Shin J, Kim KS. 5047C-reactive protein and the risk of atrial fibrillation: KOGES 12 years' follow-up study. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.5047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Y Lee
- Hanyang University, Seoul, Korea Republic of
| | - J K Park
- Hanyang University, Seoul, Korea Republic of
| | - Y H Lim
- Hanyang University, Seoul, Korea Republic of
| | - J H Shin
- Hanyang University, Seoul, Korea Republic of
| | - H C Park
- Hanyang University, Seoul, Korea Republic of
| | - J Shin
- Hanyang University, Seoul, Korea Republic of
| | - K S Kim
- Hanyang University, Seoul, Korea Republic of
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Lim YH, Wong FT, Yeo WL, Ching KC, Lim YW, Heng E, Chen S, Tsai DJ, Lauderdale TL, Shia KS, Ho YS, Hoon S, Ang EL, Zhang MM, Zhao H. Auroramycin: A Potent Antibiotic from Streptomyces roseosporus by CRISPR-Cas9 Activation. Chembiochem 2018; 19:1716-1719. [PMID: 29799651 DOI: 10.1002/cbic.201800266] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [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: 05/17/2018] [Indexed: 11/09/2022]
Abstract
Silent biosynthetic gene clusters represent a potentially rich source of new bioactive compounds. We report the discovery, characterization, and biosynthesis of a novel doubly glycosylated 24-membered polyene macrolactam from a silent biosynthetic gene cluster in Streptomyces roseosporus by using the CRISPR-Cas9 gene cluster activation strategy. Structural characterization of this polyketide, named auroramycin, revealed a rare isobutyrylmalonyl extender unit and a unique pair of amino sugars. Relative and absolute stereochemistry were determined by using a combination of spectroscopic analyses, chemical derivatization, and computational analysis. The activated gene cluster for auroramycin production was also verified by transcriptional analyses and gene deletions. Finally, auroramycin exhibited potent anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity towards clinical drug-resistant isolates.
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Affiliation(s)
- Yee Hwee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Fong Tian Wong
- Molecular Engineering Lab (MEL), Biomedical Science Institutes, A*STAR, 61 Biopolis Drive, Proteos #13-02, Singapore, 138673, Singapore
| | - Wan Lin Yeo
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
| | - Kuan Chieh Ching
- Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Yi Wee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Elena Heng
- Molecular Engineering Lab (MEL), Biomedical Science Institutes, A*STAR, 61 Biopolis Drive, Proteos #13-02, Singapore, 138673, Singapore
| | - Shuwen Chen
- Bioprocessing Technology Institute (BTI), A*STAR, 20 Biopolis Way, Centros #06-01, Singapore, 138668, Singapore
| | - De-Juin Tsai
- National Institute of Infectious Diseases and Vaccinology (DJT & TLL), and, Institute of Biotechnology and Pharmaceutical Research (KSS), National Health Research Institutes (NHRI), 35 Keyan Road, Zhunan Town, Miaoli County, 350, Taiwan, R.O.C
| | - Tsai-Ling Lauderdale
- National Institute of Infectious Diseases and Vaccinology (DJT & TLL), and, Institute of Biotechnology and Pharmaceutical Research (KSS), National Health Research Institutes (NHRI), 35 Keyan Road, Zhunan Town, Miaoli County, 350, Taiwan, R.O.C
| | - Kak-Shan Shia
- National Institute of Infectious Diseases and Vaccinology (DJT & TLL), and, Institute of Biotechnology and Pharmaceutical Research (KSS), National Health Research Institutes (NHRI), 35 Keyan Road, Zhunan Town, Miaoli County, 350, Taiwan, R.O.C
| | - Ying Swan Ho
- Bioprocessing Technology Institute (BTI), A*STAR, 20 Biopolis Way, Centros #06-01, Singapore, 138668, Singapore
| | - Shawn Hoon
- Molecular Engineering Lab (MEL), Biomedical Science Institutes, A*STAR, 61 Biopolis Drive, Proteos #13-02, Singapore, 138673, Singapore
| | - Ee Lui Ang
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
| | - Mingzi M Zhang
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
| | - Huimin Zhao
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
- 215 Roger Adams Laboratory, Box C3, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL, 61801, USA
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Yeo WL, Chew X, Smith DJ, Chan KP, Sun H, Zhao H, Lim YH, Ang EL. Probing the molecular determinants of fluorinase specificity. Chem Commun (Camb) 2018; 53:2559-2562. [PMID: 28184383 DOI: 10.1039/c6cc09213f] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular determinants of FlA1 fluorinase specificity were probed using 5'-chloro-5'-deoxyadenosine (5'-ClDA) analogs as substrates and FlA1 active site mutants. Modifications at F213 or A279 residues are beneficial towards these modified substrates, including 5'-chloro-5'-deoxy-2-ethynyladenosine, ClDEA (>10-fold activity improvement), and conferred novel activity towards substrates not readily accepted by wild-type FlA1.
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Affiliation(s)
- W L Yeo
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
| | - X Chew
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - D J Smith
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore 138671 and Biotransformation Innovation Platform, A*STAR, 61 Biopolis Drive, Proteos #04-14, Singapore 138673
| | - K P Chan
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - H Sun
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
| | - H Zhao
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669. and 215 Roger Adams Laboratory, Box C3, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue Urbana, IL 61801, USA
| | - Y H Lim
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore 138665.
| | - E L Ang
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore 138669.
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Abstract
Background Injury is the commonest cause of morbidity and mortality amongst the younger age groups. Management of injuries has been identified as one of the major health issues facing our community. The study objective was to define the epidemiology of injury related deaths in Singapore. Methods A nationwide review of all deaths arising as a result of injury in 1995 was conducted. Results There were 913 cases with an injury mortality rate of 27 per 100,000 population. Ninety-seven percent (97%) were due to blunt injury. Falls from heights from deliberate self-harm was the commonest mechanism, followed by motor vehicle collisions (MVC). Fifty-two percent (52%) of MVC deaths were motorcyclists or pillion riders. Sixty-six percent (66%) of all deaths occurred in the prehospital phase. Central nervous system injury was the main cause of hospital deaths. Conclusion Results from this study will help our community focus on the appropriate preventive strategies to reduce mortality and the cost of injuries to our society.
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Affiliation(s)
- MKF Leong
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - S Mujumdar
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - L Raman
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - YH Lim
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
| | - TC Chao
- Institute of Forensic Medicine
| | - V Anantharaman
- Singapore General Hospital, Department of Emergency Medicine, Outram Road, S169608, Singapore
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Lim YH, Hendricks J. A Case of Nonfatal Non-Collapsed Patient with Extreme Hyperkalaemia. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790701400407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This is a report of a non-collapsed patient with nonfatal, extreme hyperkalaemia of 10.7 mmol/L. The patient's hyperkalaemia was initially treated in the Emergency Department and then transferred to the Department of Renal Medicine of another hospital for further stabilisation. There have only been a few reported cases of successful management of extreme hyperkalaemia in excess of 10.0 mmol/L.
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Lim YH, Yeo A, Koh MP, Wong CY. Severely Injured Patients Presenting to the Singapore General Hospital: a one Year Study. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790301000104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Study objectives To determine the quantity and resource utilisation in management of the severely injured patients presenting at the Singapore General Hospital (SGH). Method All patients who were initially triaged to the hospital Emergency Department's (ED) resuscitation room and all trauma related mortality in the year 1998 were studied. All records were traced and the cases were followed up. Important outcomes studied were mortality and length of hospital stay. Results Three hundred and forty-seven (0.2%) severely injured patients who were initially treated at the ED's resuscitation room were studied. The median age of the patients was 32 years old. Male patients formed 82.1% of the total. The three main causes of trauma in such patients were fall from height, motor vehicle related accidents and penetrating injuries caused by sharp instruments and firearms. Of all the patients, 62.8% were admitted to the ED between 1601 hours to 0759 hours and 30.5% of all severely injured patients were treated at the ED on weekends. One hundred and twenty three (35.4%) patients had emergency surgery within 24 hours of admission to the ED and 42.4% of the patients had an ISS score of 16 or more; 22.8% of patients had ISS score of 25 or more. The mortality of patients with ISS score of 25 or more was 39.2%. Conclusion One percent of all new ED patients with trauma were classified as ‘severely’ injured and these occurred mostly outside “normal working hours”. There was significant mortality in patients with ISS score of 25 or more.
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Affiliation(s)
| | - A Yeo
- Singapore General Hospital, Department of General Surgery and Trauma Service
| | - MP Koh
- Singapore General Hospital, Department of General Surgery
| | - CY Wong
- Singapore General Hospital, Department of General Surgery
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Lim YH, Anantharaman V. Patients who Self-Discharge from the Emergency Department: a Three-Month Telephone Survey. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790401100105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Study objectives To determine the main causes and outcomes of patients who self-discharged from the Emergency Department (ED). Methods Records of all patients who self-discharged from the ED of a tertiary level hospital were traced and telephone interviews were conducted. The duration of the study was from 15 July 2002 to 14 October 2002. Results There were 28,898 new attendances during the period of study and of these, 450 (1.6%) patients signed the self-discharge form. Of the 357 patients recruited into the study, the majority signed the self-discharge form because of refusal of admission to inpatient units (52.1%) or the ED observation ward (43.4%) for further treatment. One hundred and thirteen (31.7%) patients acknowledged that they were unwell during the interview and 85 (23.8%) patients sought some form of medical attention after leaving the ED. Conclusion Most of the patients who self-discharged from the ED were for personal reasons and very few were due to financial reasons.
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Affiliation(s)
- YH Lim
- Singapore General Hospital, Department of Emergency Medicine, Singapore 169608
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Abstract
This is a rare case of sagittal sinus thrombosis occurring in the first trimester of pregnancy. A literature review was performed.
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Yong FF, Mak AM, Wu W, Sullivan MB, Robins EG, Johannes CW, Jong H, Lim YH. Empirical and Computational Insights into N-Arylation Reactions Catalyzed by Palladium meta
-Terarylphosphine Catalyst. Chempluschem 2017; 82:750-757. [DOI: 10.1002/cplu.201700042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Revised: 03/10/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Fui Fong Yong
- Organic Chemistry, Institute of Chemical; Engineering Sciences (ICES); Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove, Neuros, #07-01 Singapore 138665 Singapore
| | - Adrian M. Mak
- Institute of High Performance Computing (IHPC); Agency for Science, Technology and Research (A*STAR); 1 Fusionopolis Way, #16-16 Connexis Singapore 138632 Singapore
| | - Wenqin Wu
- Organic Chemistry, Institute of Chemical; Engineering Sciences (ICES); Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove, Neuros, #07-01 Singapore 138665 Singapore
| | - Michael B. Sullivan
- Institute of High Performance Computing (IHPC); Agency for Science, Technology and Research (A*STAR); 1 Fusionopolis Way, #16-16 Connexis Singapore 138632 Singapore
| | - Edward G. Robins
- Singapore Bioimaging Consortium (SBIC); Agency for Science, Technology and Research (A*STAR); 11 Biopolis Way, Helios, #02-02 Singapore 138667 Singapore
| | - Charles W. Johannes
- Organic Chemistry, Institute of Chemical; Engineering Sciences (ICES); Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove, Neuros, #07-01 Singapore 138665 Singapore
| | - Howard Jong
- Organic Chemistry, Institute of Chemical; Engineering Sciences (ICES); Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove, Neuros, #07-01 Singapore 138665 Singapore
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical; Engineering Sciences (ICES); Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove, Neuros, #07-01 Singapore 138665 Singapore
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Zhang MM, Wong FT, Wang Y, Luo S, Lim YH, Heng E, Yeo WL, Cobb RE, Enghiad B, Ang EL, Zhao H. CRISPR-Cas9 strategy for activation of silent Streptomyces biosynthetic gene clusters. Nat Chem Biol 2017; 13:nchembio.2341. [PMID: 28398287 PMCID: PMC5634907 DOI: 10.1038/nchembio.2341] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 01/13/2017] [Indexed: 02/02/2023]
Abstract
Here we report an efficient CRISPR-Cas9 knock-in strategy to activate silent biosynthetic gene clusters (BGCs) in streptomycetes. We applied this one-step strategy to activate multiple BGCs of different classes in five Streptomyces species and triggered the production of unique metabolites, including a novel pentangular type II polyketide in Streptomyces viridochromogenes. This potentially scalable strategy complements existing activation approaches and facilitates discovery efforts to uncover new compounds with interesting bioactivities.
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Affiliation(s)
- Mingzi M Zhang
- Metabolic Engineering Research Laboratory, Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore
| | - Fong Tian Wong
- Molecular Engineering Lab, Biomedical Science Institutes, A*STAR, Singapore
| | - Yajie Wang
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Shangwen Luo
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences, A*STAR, Singapore
| | - Elena Heng
- Molecular Engineering Lab, Biomedical Science Institutes, A*STAR, Singapore
| | - Wan Lin Yeo
- Metabolic Engineering Research Laboratory, Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore
| | - Ryan E Cobb
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Behnam Enghiad
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Ee Lui Ang
- Metabolic Engineering Research Laboratory, Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore
| | - Huimin Zhao
- Metabolic Engineering Research Laboratory, Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), Singapore
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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Jong H, Eey STC, Lim YH, Pandey S, Iqbal NAB, Yong FF, Robins EG, Johannes CW. One-Pot Palladium-Catalyzed Cross-Coupling Treble of Borylation, the Suzuki Reaction and Amination. Adv Synth Catal 2017. [DOI: 10.1002/adsc.201600708] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Howard Jong
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Stanley T.-C. Eey
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Sangeeta Pandey
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Nurul Azmah Bte Iqbal
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Fui Fong Yong
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
| | - Edward G. Robins
- Singapore Bioimaging Consortium (SBIC), Agency for Science, Technology and Research (A*STAR); 11 Biopolis Way, Helios, #02-02 Singapore 138667
| | - Charles W. Johannes
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR); 8 Biomedical Grove Neuros #07-01 Singapore 138665
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Ovejero D, Lim YH, Boyce AM, Gafni RI, McCarthy E, Nguyen TA, Eichenfield LF, DeKlotz CMC, Guthrie LC, Tosi LL, Thornton PS, Choate KA, Collins MT. Cutaneous skeletal hypophosphatemia syndrome: clinical spectrum, natural history, and treatment. Osteoporos Int 2016; 27:3615-3626. [PMID: 27497815 PMCID: PMC6908308 DOI: 10.1007/s00198-016-3702-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/06/2016] [Indexed: 12/01/2022]
Abstract
UNLABELLED Cutaneous skeletal hypophosphatemia syndrome (CSHS), caused by somatic RAS mutations, features excess fibroblast growth factor-23 (FGF23) and skeletal dysplasia. Records from 56 individuals were reviewed and demonstrated fractures, scoliosis, and non-congenital hypophosphatemia that in some cases were resolved. Phosphate and calcitriol, but not skin lesion removal, were effective at controlling hypophosphatemia. No skeletal malignancies were found. PURPOSE CSHS is a disorder defined by the association of epidermal and/or melanocytic nevi, a mosaic skeletal dysplasia, and an FGF23-mediated hypophosphatemia. To date, somatic RAS mutations have been identified in all patients whose affected tissue has undergone DNA sequencing. However, the clinical spectrum and treatment are poorly defined in CSHS. The purpose of this study is to determine the spectrum of the phenotype, natural history of the disease, and response to treatment of hypophosphatemia. METHODS Five CSHS subjects underwent prospective data collection at clinical research centers. A review of the literature identified 45 reports that included a total of 51 additional patients, in whom the findings were compatible with CSHS. Data on nevi subtypes, bone histology, mineral and skeletal disorders, abnormalities in other tissues, and response to treatment of hypophosphatemia were analyzed. RESULTS Fractures, limb deformities, and scoliosis affected most CSHS subjects. Hypophosphatemia was not present at birth. Histology revealed severe osteomalacia but no other abnormalities. Skeletal dysplasia was reported in all anatomical compartments, though less frequently in the spine; there was no clear correlation between the location of nevi and the skeletal lesions. Phosphate and calcitriol supplementation was the most effective therapy for rickets. Convincing data that nevi removal improved blood phosphate levels was lacking. An age-dependent improvement in mineral abnormalities was observed. A spectrum of extra-osseous/extra-cutaneous manifestations that included both benign and malignant neoplasms was present in many subjects, though osteosarcoma remains unreported. CONCLUSION An understanding of the spectrum, natural history, and efficacy of treatment of hypophosphatemia in CSHS may improve the care of these patients.
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Affiliation(s)
- D Ovejero
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
- Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Barcelona, Spain
| | - Y H Lim
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - A M Boyce
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - R I Gafni
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - E McCarthy
- Department of Pathology, The Johns Hopkins University, Baltimore, MD, USA
| | - T A Nguyen
- Albert Einstein College of Medicine, Bronx, NY, USA
- Departments of Dermatology and Pediatrics, San Diego and Rady Children's Hospital, University of California, San Diego, CA, USA
| | - L F Eichenfield
- Departments of Dermatology and Pediatrics, San Diego and Rady Children's Hospital, University of California, San Diego, CA, USA
| | - C M C DeKlotz
- Division Dermatology, Department of Medicine and Department of Pediatrics, Georgetown University Medical Center, Washington, DC, USA
| | - L C Guthrie
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA
| | - L L Tosi
- Bone Health Program, Division of Orthopaedics and Sports Medicine, Children's National Health System, Washington, DC, USA
| | - P S Thornton
- Department of Endocrinology and Diabetes, Cook Children Medical Center, Fort Worth, TX, USA
| | - K A Choate
- Department of Dermatology, Yale University School of Medicine, New Haven, CT, USA
| | - M T Collins
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Disease Branch, National ADDRESSES, references BRACKETS, National Institute of Dental and Craniofacial Research, National Institutes of Health, 30 Convent Drive, Room 228, MSC 4320, Bethesda, MD, 20892-4320, USA.
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Sun H, Yeo WL, Lim YH, Chew X, Smith DJ, Xue B, Chan KP, Robinson RC, Robins EG, Zhao H, Ang EL. Directed Evolution of a Fluorinase for Improved Fluorination Efficiency with a Non-native Substrate. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201606722] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Huihua Sun
- Metabolic Engineering Research Laboratory (MERL); Science and Engineering Institutes; Agency for Science, Technology, and Research (A*STAR); 31 Biopolis Way, Nanos #01-01 Singapore 138669 Singapore
| | - Wan Lin Yeo
- Metabolic Engineering Research Laboratory (MERL); Science and Engineering Institutes; Agency for Science, Technology, and Research (A*STAR); 31 Biopolis Way, Nanos #01-01 Singapore 138669 Singapore
| | - Yee Hwee Lim
- Institute of Chemical and Engineering Sciences (ICES); A*STAR; 8 Biomedical Grove, Neuros #07-01/02/03 Singapore 138665 Singapore
| | - Xinying Chew
- Institute of Chemical and Engineering Sciences (ICES); A*STAR; 8 Biomedical Grove, Neuros #07-01/02/03 Singapore 138665 Singapore
| | - Derek John Smith
- Bioinformatics Institute; A*STAR; 30 Biopolis Street, Matrix #07-01 Singapore 138671 Singapore
- Biotransformation Innovation Platform; 61 Biopolis Drive, Proteos #04-14 Singapore 138673 Singapore
| | - Bo Xue
- Institute of Molecular and Cell Biology (IMCB); A*STAR; 61 Biopolis Drive, Proteos #03-15 Singapore 138673 Singapore
| | - Kok Ping Chan
- Institute of Chemical and Engineering Sciences (ICES); A*STAR; 8 Biomedical Grove, Neuros #07-01/02/03 Singapore 138665 Singapore
| | - Robert C. Robinson
- Institute of Molecular and Cell Biology (IMCB); A*STAR; 61 Biopolis Drive, Proteos #03-15 Singapore 138673 Singapore
- Department of Biochemistry; Yong Loo Lin School of Medicine; National University of Singapore; Singapore 117597 Singapore
- NTU Institute of Structural Biology; Nanyang Technological University (NTU); 59 Nanyang Drive Singapore 636921 Singapore
- School of Biological Sciences; NTU; 60 Nanyang Drive Singapore 637551 Singapore
- Lee Kong Chian School of Medicine; 50 Nanyang Avenue Singapore 639798 Singapore
| | - Edward G. Robins
- Singapore Bioimaging Consortium (SBIC); A*STAR; 11 Biopolis way, #02-02 Singapore 138667 Singapore
| | - Huimin Zhao
- Metabolic Engineering Research Laboratory (MERL); Science and Engineering Institutes; Agency for Science, Technology, and Research (A*STAR); 31 Biopolis Way, Nanos #01-01 Singapore 138669 Singapore
- 215 Roger Adams Laboratory, Box C3; University of Illinois at Urbana-Champaign; 600 South Mathews Avenue Urbana IL 61801 USA
| | - Ee Lui Ang
- Metabolic Engineering Research Laboratory (MERL); Science and Engineering Institutes; Agency for Science, Technology, and Research (A*STAR); 31 Biopolis Way, Nanos #01-01 Singapore 138669 Singapore
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40
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Sun H, Yeo WL, Lim YH, Chew X, Smith DJ, Xue B, Chan KP, Robinson RC, Robins EG, Zhao H, Ang EL. Directed Evolution of a Fluorinase for Improved Fluorination Efficiency with a Non-native Substrate. Angew Chem Int Ed Engl 2016; 55:14277-14280. [PMID: 27739177 DOI: 10.1002/anie.201606722] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [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: 07/21/2016] [Revised: 08/24/2016] [Indexed: 11/09/2022]
Abstract
Fluorinases offer an environmentally friendly alternative for selective fluorination under mild conditions. However, their diversity is limited in nature and they have yet to be engineered through directed evolution. Herein, we report the directed evolution of the fluorinase FlA1 for improved conversion of the non-native substrate 5'-chloro-5'-deoxyadenosine (5'-ClDA) into 5'-fluoro-5'-deoxyadenosine (5'-FDA). The evolved variants, fah2081 (A279Y) and fah2114 (F213Y, A279L), were successfully applied in the radiosynthesis of 5'-[18 F]FDA, with overall radiochemical conversion (RCC) more than 3-fold higher than wild-type FlA1. Kinetic studies of the two-step reaction revealed that the variants show a significantly improved kcat value in the conversion of 5'-ClDA into S-adenosyl-l-methionine (SAM) but a reduced kcat value in the conversion of SAM into 5'-FDA.
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Affiliation(s)
- Huihua Sun
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
| | - Wan Lin Yeo
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore
| | - Yee Hwee Lim
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Xinying Chew
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Derek John Smith
- Bioinformatics Institute, A*STAR, 30 Biopolis Street, Matrix #07-01, Singapore, 138671, Singapore.,Biotransformation Innovation Platform, 61 Biopolis Drive, Proteos #04-14, Singapore, 138673, Singapore
| | - Bo Xue
- Institute of Molecular and Cell Biology (IMCB), A*STAR, 61 Biopolis Drive, Proteos #03-15, Singapore, 138673, Singapore
| | - Kok Ping Chan
- Institute of Chemical and Engineering Sciences (ICES), A*STAR, 8 Biomedical Grove, Neuros #07-01/02/03, Singapore, 138665, Singapore
| | - Robert C Robinson
- Institute of Molecular and Cell Biology (IMCB), A*STAR, 61 Biopolis Drive, Proteos #03-15, Singapore, 138673, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.,NTU Institute of Structural Biology, Nanyang Technological University (NTU), 59 Nanyang Drive, Singapore, 636921, Singapore.,School of Biological Sciences, NTU, 60 Nanyang Drive, Singapore, 637551, Singapore.,Lee Kong Chian School of Medicine, 50 Nanyang Avenue, Singapore, 639798, Singapore
| | - Edward G Robins
- Singapore Bioimaging Consortium (SBIC), A*STAR, 11 Biopolis way, #02-02, Singapore, 138667, Singapore
| | - Huimin Zhao
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore. .,215 Roger Adams Laboratory, Box C3, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL, 61801, USA.
| | - Ee Lui Ang
- Metabolic Engineering Research Laboratory (MERL), Science and Engineering Institutes, Agency for Science, Technology, and Research (A*STAR), 31 Biopolis Way, Nanos #01-01, Singapore, 138669, Singapore.
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Mak AM, Lim YH, Jong H, Yang Y, Johannes CW, Robins EG, Sullivan MB. Mechanistic Insights and Implications of Dearomative Rearrangement in Copper-Free Sonogashira Cross-Coupling Catalyzed by Pd-Cy*Phine. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00186] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Adrian M. Mak
- Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
| | - Yee Hwee Lim
- Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Howard Jong
- Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Yong Yang
- Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Charles W. Johannes
- Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros #07-01, Singapore 138665, Singapore
| | - Edward G. Robins
- Singapore Bioimaging Consortium, 11 Biopolis Way, Helios #02-02, Singapore 138667, Singapore
| | - Michael B. Sullivan
- Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632, Singapore
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Abstract
Expedient protocol to access a wide range of internal alkynes and symmetrical di(heteroaryl)alkynes via tandem decarboxylative–Sonogashira cross-coupling.
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Affiliation(s)
- Yong Yang
- Organic Chemistry
- Institute of Chemical & Engineering Sciences (ICES)
- Agency of Science, Technology and Research (A*STAR)
- Singapore 138665
| | - Yee Hwee Lim
- Organic Chemistry
- Institute of Chemical & Engineering Sciences (ICES)
- Agency of Science, Technology and Research (A*STAR)
- Singapore 138665
| | - Edward G. Robins
- Singapore Bioimaging Consortium (SBIC)
- Agency of Science, Technology and Research (A*STAR)
- Singapore 138667
| | - Charles W. Johannes
- Organic Chemistry
- Institute of Chemical & Engineering Sciences (ICES)
- Agency of Science, Technology and Research (A*STAR)
- Singapore 138665
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Tay DW, Jong H, Lim YH, Wu W, Chew X, Robins EG, Johannes CW. Palladium-meta-Terarylphosphine Catalyst for the Mizoroki–Heck Reaction of (Hetero)Aryl Bromides and Functional Olefins. J Org Chem 2015; 80:4054-63. [DOI: 10.1021/acs.joc.5b00386] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Daniel Weiliang Tay
- Singapore
Bioimaging Consortium (SBIC), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #01-02, Singapore 138667
| | - Howard Jong
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #03-08, Singapore 138667
| | - Yee Hwee Lim
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #03-08, Singapore 138667
| | - Wenqin Wu
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #03-08, Singapore 138667
| | - Xinying Chew
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #03-08, Singapore 138667
| | - Edward G. Robins
- Singapore
Bioimaging Consortium (SBIC), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #01-02, Singapore 138667
| | - Charles W. Johannes
- Organic Chemistry, Institute of Chemical & Engineering Sciences (ICES), Agency of Science, Technology and Research (A*STAR), 11 Biopolis Way, Helios, #03-08, Singapore 138667
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44
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Yang Y, Lim JFY, Chew X, Robins EG, Johannes CW, Lim YH, Jong H. Palladium precatalysts containing meta-terarylphosphine ligands for expedient copper-free Sonogashira cross-coupling reactions. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00507h] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Novel precatalysts containing meta-terarylphosphine ligands have set a new standard for high performance and practicality in copper-free Sonogashira cross-coupling catalysis using simple and reliable protocols.
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Affiliation(s)
- Yong Yang
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
| | - Joyce Fen Yan Lim
- School of Medical and Life Sciences
- Nanyang Polytechnic
- Singapore 569830
| | - Xinying Chew
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
| | - Edward G. Robins
- Singapore Bioimaging Consortium (SBIC)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
| | - Charles W. Johannes
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
| | - Yee Hwee Lim
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
| | - Howard Jong
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science
- Technology and Research (A*STAR)
- Singapore 138667
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Yang Y, Chew X, Johannes CW, Robins EG, Jong H, Lim YH. A Versatile and Efficient Palladium-meta-Terarylphosphine Catalyst for the Copper-Free Sonogashira Coupling of (Hetero-)Aryl Chlorides and Alkynes. European J Org Chem 2014. [DOI: 10.1002/ejoc.201402699] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Terminal alkynes can be chemoselectively transformed into enol ethers via a formal tandem Markovnikov hydration-Smiles type rearrangement using Zn(OTf)2.
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Affiliation(s)
- Xinying Chew
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science, Technology and Research (A*STAR)
- Singapore 138667, Singapore
| | - Yuhan Lin
- Singapore Bioimaging Consortium (SBIC)
- Agency for Science, Technology and Research (A*STAR)
- Singapore 138667, Singapore
| | - Yee Hwee Lim
- Organic Chemistry
- Institute of Chemical and Engineering Sciences (ICES)
- Agency for Science, Technology and Research (A*STAR)
- Singapore 138667, Singapore
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47
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Lim YH, Ong Q, Duong HA, Nguyen TM, Johannes CW. Direct conversion of indoles to 3,3-difluoro-2-oxindoles via electrophilic fluorination. Org Lett 2012; 14:5676-9. [PMID: 23101562 DOI: 10.1021/ol302666d] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
3,3-Difluoro-2-oxindoles can be obtained directly from indoles in moderate yields via electrophilic fluorination using N-fluorobenzenesulfonimide as a mild fluorinating reagent. The presence of tert-butyl hydroperoxide during the reaction, together with additional heating after quenching the reaction with triethylamine, is beneficial to the formation of the desired product.
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Affiliation(s)
- Yee Hwee Lim
- Organic Chemistry, Institute of Chemical and Engineering Sciences (ICES), Agency for Science, Technology and Research (A*STAR), 11 Biopolis Way, The Helios Block, #03-08, Singapore 138667.
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48
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Gilbert EA, Lim YH, Vickaryous MK, Armstrong CL. Heterochronic protein expression patterns in the developing embryonic chick cerebellum. Anat Rec (Hoboken) 2012; 295:1669-82. [PMID: 22865685 DOI: 10.1002/ar.22544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 06/12/2012] [Accepted: 07/11/2012] [Indexed: 12/18/2022]
Abstract
The advantages of the embryonic chick as a model for studying neural development range from the relatively low cost of fertilized eggs to the rapid rate of development. We investigated in ovo cerebellar development in the chick, which has a nearly identical embryonic period as the mouse (19-22 days). We focused on three antigens: Calbindin (CB), Zebrin II (ZII), and Calretinin (CR), and our results demonstrate asynchronous expression patterns during cerebellar development. Presumptive CB+ Purkinje cells are first observed at embryonic day (E)10 in clusters in posterior cerebellum. At E12, corresponding with global expression of CB across the cerebellum, Purkinje cells began to express ZII. By E14-E16, Purkinje cells disperse into a monolayer and develop a pattern of alternating immunopositive and immunonegative ZII stripes. CR is initially expressed by clusters of presumptive Purkinje cells in the nodular zone at E8. However, this expression is transient and at later stages, CR is largely confined to the granule and molecular layers. Before hatch (E18-E20), Purkinje cells adopt a morphologically mature phenotype with complex dendritic arborizations. Comparing this data to that seen in mice, we found that the sequence of Purkinje cell formation, protein expression, and development is similar in both species, but these events consistently begin ∼5-7 days earlier in the precocial chick cerebellum, suggesting an important role for heterochrony in neurodevelopment.
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Affiliation(s)
- E A Gilbert
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Road, Guelph, Ontario, Canada
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49
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Gao Z, Lim YH, Tredwell M, Li L, Verhoog S, Hopkinson M, Kaluza W, Collier TL, Passchier J, Huiban M, Gouverneur V. Metal-Free Oxidative Fluorination of Phenols with [18F]Fluoride. Angew Chem Int Ed Engl 2012; 51:6733-7. [DOI: 10.1002/anie.201201502] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 04/05/2012] [Indexed: 11/12/2022]
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50
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Lim BC, Ki CS, Cho A, Hwang H, Kim KJ, Hwang YS, Kim YE, Yun JY, Jeon BS, Lim YH, Paek SH, Chae JH. Pantothenate kinase-associated neurodegeneration in Korea: recurrent R440P mutation in PANK2 and outcome of deep brain stimulation. Eur J Neurol 2011; 19:556-61. [PMID: 22103354 DOI: 10.1111/j.1468-1331.2011.03589.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND PURPOSE The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS). METHODS Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI). Pallidal DBS was conducted in four patients, and the outcomes were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). RESULTS A PANK2 mutation was identified in both alleles in all patients. The most prevalent mutation was c.1319G>C (p.R440P) in 8/22 mutated alleles (36%). An intragenic deletion ranging from exons 2 to 4 was found in one allele (1/22, 4.5%) using deletion/duplication analysis. The outcome of pallidal DBS was favorable in two patients with atypical PKAN and moderate severity of dystonia. However, two patients with typical PKAN and relatively severe symptoms showed variable responses. CONCLUSIONS The c.1319G>C (p.R440P) mutation appears to be a founder genotype among Korean patients with PKAN. Furthermore, this study provides additional data for the recent international effort to evaluate the efficacy of pallidal DBS in the treatment of patients with PKAN.
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Affiliation(s)
- B C Lim
- Department of Pediatrics, Seoul National University College of Medicine, Seoul National University Children's Hospital, Seoul, Korea.
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