1
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Kim DS, Kim Y, Lee D, Lee Y. Design of 2-Pyridone Fluorophores for Brighter Emissions at Longer Wavelengths. Chemistry 2024:e202303458. [PMID: 38221142 DOI: 10.1002/chem.202303458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/18/2023] [Accepted: 01/11/2024] [Indexed: 01/16/2024]
Abstract
The recent discovery of blue fluorophores with high quantum yields based on pyridone structures inspired the development of new low-molecular-weight fluorophores with bright emissions at tunable wavelengths, which are highly attractive for various applications. In this study, we propose a rational design strategy for 2-pyridone-based fluorophores with bright emissions at long wavelengths. With a detailed understanding of the positional substitution effects on each carbon atom of the 2-pyridone core, we developed a bright blue fluorophore (λabs =377 nm; λem =433 nm; ϵ=13,200 M-1 cm-1 ; ϕF =88 %) through C3 -aryl and C4 -ester substitutions followed by cyclization. Furthermore, by applying the intramolecular charge transfer (ICT) principle, we invented a bright green fluorophore through C3 - and C4 -diester and C6 -aryl substitutions. The ICT fluorophore based on the pyridone structure shows large molar absorptivity (ϵ=20,100 M-1 cm-1 ), longer emission wavelength (λem =539 nm), high emission quantum yield (ϕF =74 %), and large Stokes shift (Δv=5720 cm-1 ), which are comparable to those of practical fluorescent probes.
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Affiliation(s)
- Dong Sun Kim
- Department of Chemistry, College of Natural Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Younghun Kim
- Department of Chemistry, College of Natural Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Dongwhan Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Yan Lee
- Department of Chemistry, College of Natural Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08826, Republic of Korea
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2
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Wu Y, Jhong Y, Lin H, Swain SP, Tsai HG, Hou D. Organocatalyzed Enantioselective Michael Addition of 2‐Hydroxypyridines and α,β‐Unsaturated 1,4‐Dicarbonyl Compounds. Adv Synth Catal 2019. [DOI: 10.1002/adsc.201900997] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yu‐Chun Wu
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
| | - Yi Jhong
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
| | - Hui‐Jie Lin
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
| | - Sharada Prasanna Swain
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
- Assistant Professor-Selection Grade, School of Health SciencesUniversity of Petroleum and Energy Studies Bidholi, Dehradun- 248007 India
| | - Hui‐Hsu Gavin Tsai
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
- Research Center of New Generation Light Driven Photovoltaic Module InstitutionNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
| | - Duen‐Ren Hou
- Department of ChemistryNational Central University 300 Jhong-Da Rd., Jhong-Li Taoyuan Taiwan 32001
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3
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Dong L, Liu Y. Comparative studies of the catalytic mechanisms of two chorismatases: CH-fkbo and CH-Hyg5. Proteins 2017; 85:1146-1158. [DOI: 10.1002/prot.25279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 02/13/2017] [Accepted: 02/21/2017] [Indexed: 01/11/2023]
Affiliation(s)
- Lihua Dong
- School of Chemistry and Chemical Engineering; Shandong University; Jinan Shandong 250100 China
- School of Chemistry and Chemical Engineering; Qilu Normal University; Jinan Shandong 250013 China
| | - Yongjun Liu
- School of Chemistry and Chemical Engineering; Shandong University; Jinan Shandong 250100 China
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4
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Zhang XK, Liu F, Fiers WD, Sun WM, Guo J, Liu Z, Aldrich CC. Synthesis of Transition-State Inhibitors of Chorismate Utilizing Enzymes from Bromobenzene cis-1,2-Dihydrodiol. J Org Chem 2017; 82:3432-3440. [PMID: 28282140 DOI: 10.1021/acs.joc.6b02801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In order to survive in a mammalian host, Mycobacterium tuberculosis (Mtb) produces aryl-capped siderophores known as the mycobactins for iron acquisition. Salicylic acid is a key building block of the mycobactin core and is synthesized by the bifunctional enzyme MbtI, which converts chorismate into isochorismate via a SN2″ reaction followed by further transformation into salicylate through a [3,3]-sigmatropic rearrangement. MbtI belongs to a family of chorismate-utilizing enzymes (CUEs) that have conserved topology and active site residues. The transition-state inhibitor 1 described by Bartlett, Kozlowski, and co-workers is the most potent reported inhibitor to date of CUEs. Herein, we disclose a concise asymmetric synthesis and the accompanying biochemical characterization of 1 along with three closely related analogues beginning from bromobenzene cis-1S,2S-dihydrodiol produced through microbial oxidation that features a series of regio- and stereoselective transformations for introduction of the C-4 hydroxy and C-6 amino substituents. The flexible synthesis enables late-stage introduction of the carboxy group and other bioisosteres at the C-1 position as well as installation of the enol-pyruvate side chain at the C-5 position.
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Affiliation(s)
- Xiao-Kang Zhang
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , 152 Luoyu Road, Wuhan, Hubei 430079, People's Republic of China
| | - Feng Liu
- Department of Medicinal Chemistry, University of Minnesota , 308 Harvard Street Southeast, 8-174 WDH, Minneapolis, Minnesota 55455, United States
| | - William D Fiers
- Department of Medicinal Chemistry, University of Minnesota , 308 Harvard Street Southeast, 8-174 WDH, Minneapolis, Minnesota 55455, United States
| | - Wen-Mei Sun
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , 152 Luoyu Road, Wuhan, Hubei 430079, People's Republic of China
| | - Jun Guo
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , 152 Luoyu Road, Wuhan, Hubei 430079, People's Republic of China
| | - Zheng Liu
- Key Laboratory of Pesticide & Chemical Biology of Ministry of Education, College of Chemistry, Central China Normal University , 152 Luoyu Road, Wuhan, Hubei 430079, People's Republic of China
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota , 308 Harvard Street Southeast, 8-174 WDH, Minneapolis, Minnesota 55455, United States
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5
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Meneely KM, Sundlov JA, Gulick AM, Moran GR, Lamb AL. An Open and Shut Case: The Interaction of Magnesium with MST Enzymes. J Am Chem Soc 2016; 138:9277-93. [PMID: 27373320 PMCID: PMC5029964 DOI: 10.1021/jacs.6b05134] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
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The shikimate pathway of bacteria,
fungi, and plants generates
chorismate, which is drawn into biosynthetic pathways that form aromatic
amino acids and other important metabolites, including folates, menaquinone,
and siderophores. Many of the pathways initiated at this branch point
transform chorismate using an MST enzyme. The MST enzymes (menaquinone, siderophore, and tryptophan biosynthetic enzymes) are structurally homologous and magnesium-dependent,
and all perform similar chemical permutations to chorismate by nucleophilic
addition (hydroxyl or amine) at the 2-position of the ring, inducing
displacement of the 4-hydroxyl. The isomerase enzymes release isochorismate
or aminodeoxychorismate as the product, while the synthase enzymes
also have lyase activity that displaces pyruvate to form either salicylate
or anthranilate. This has led to the hypothesis that the isomerase
and lyase activities performed by the MST enzymes are functionally
conserved. Here we have developed tailored pre-steady-state approaches
to establish the kinetic mechanisms of the isochorismate and salicylate
synthase enzymes of siderophore biosynthesis. Our data are centered
on the role of magnesium ions, which inhibit the isochorismate synthase
enzymes but not the salicylate synthase enzymes. Prior structural
data have suggested that binding of the metal ion occludes access
or egress of substrates. Our kinetic data indicate that for the production
of isochorismate, a high magnesium ion concentration suppresses the
rate of release of product, accounting for the observed inhibition
and establishing the basis of the ordered-addition kinetic mechanism.
Moreover, we show that isochorismate is channeled through the synthase
reaction as an intermediate that is retained in the active site by
the magnesium ion. Indeed, the lyase-active enzyme has 3 orders of
magnitude higher affinity for the isochorismate complex relative to
the chorismate complex. Apparent negative-feedback inhibition by ferrous
ions is documented at nanomolar concentrations, which is a potentially
physiologically relevant mode of regulation for siderophore biosynthesis
in vivo.
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Affiliation(s)
- Kathleen M Meneely
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
| | - Jesse A Sundlov
- Hauptman-Woodward Medical Research Institute , 700 Ellicott Street, Buffalo, New York 14203, United States
| | - Andrew M Gulick
- Hauptman-Woodward Medical Research Institute , 700 Ellicott Street, Buffalo, New York 14203, United States
| | - Graham R Moran
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee , Milwaukee, Wisconsin 53201, United States
| | - Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas , Lawrence, Kansas 66045, United States
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6
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Fernandes JDS, Martho K, Tofik V, Vallim MA, Pascon RC. The Role of Amino Acid Permeases and Tryptophan Biosynthesis in Cryptococcus neoformans Survival. PLoS One 2015; 10:e0132369. [PMID: 26162077 PMCID: PMC4498599 DOI: 10.1371/journal.pone.0132369] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/14/2015] [Indexed: 01/25/2023] Open
Abstract
Metabolic diversity is an important factor during microbial adaptation to different environments. Among metabolic processes, amino acid biosynthesis has been demonstrated to be relevant for survival for many microbial pathogens, whereas the association between pathogenesis and amino acid uptake and recycling are less well-established. Cryptococcus neoformans is an opportunistic fungal pathogen with many habitats. As a result, it faces frequent metabolic shifts and challenges during its life cycle. Here we studied the C. neoformans tryptophan biosynthetic pathway and found that the pathway is essential. RNAi indicated that interruptions in the biosynthetic pathway render strains inviable. However, auxotroph complementation can be partially achieved by tryptophan uptake when a non preferred nitrogen source and lower growth temperature are applied, suggesting that amino acid permeases may be the target of nitrogen catabolism repression (NCR). We used bioinformatics to search for amino acid permeases in the C. neoformans and found eight potential global permeases (AAP1 to AAP8). The transcriptional profile of them revealed that they are subjected to regulatory mechanisms which are known to respond to nutritional status in other fungi, such as (i) quality of nitrogen (Nitrogen Catabolism Repression, NCR) and carbon sources (Carbon Catabolism Repression, CCR), (ii) amino acid availability in the extracellular environment (SPS-sensing) and (iii) nutritional deprivation (Global Amino Acid Control, GAAC). This study shows that C. neoformans has fewer amino acid permeases than other model yeasts, and that these proteins may be subjected to complex regulatory mechanisms. Our data suggest that the C. neoformans tryptophan biosynthetic pathway is an excellent pharmacological target. Furthermore, inhibitors of this pathway cause Cryptococcus growth arrest in vitro.
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Affiliation(s)
- João Daniel Santos Fernandes
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Laboratório de Interações Microbianas (Laboratory 29), Rua Arthur Ridel, 275, 09972–270, Bairro Eldorado, Diadema, SP, Brazil
- Universidade de São Paulo, Avenida Prof. Lineu Prestes, 2415 Edifício ICB – III, Cidade Universitária, CEP 05508–900, São Paulo, SP, Brazil
| | - Kevin Martho
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Laboratório de Interações Microbianas (Laboratory 29), Rua Arthur Ridel, 275, 09972–270, Bairro Eldorado, Diadema, SP, Brazil
| | - Veridiana Tofik
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Laboratório de Interações Microbianas (Laboratory 29), Rua Arthur Ridel, 275, 09972–270, Bairro Eldorado, Diadema, SP, Brazil
| | - Marcelo A. Vallim
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Laboratório de Interações Microbianas (Laboratory 29), Rua Arthur Ridel, 275, 09972–270, Bairro Eldorado, Diadema, SP, Brazil
| | - Renata C. Pascon
- Departamento de Ciências Biológicas, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Campus Diadema, Laboratório de Interações Microbianas (Laboratory 29), Rua Arthur Ridel, 275, 09972–270, Bairro Eldorado, Diadema, SP, Brazil
- * E-mail:
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7
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Liu Z, Liu F, Aldrich CC. Stereocontrolled Synthesis of a Potential Transition-State Inhibitor of the Salicylate Synthase MbtI from Mycobacterium tuberculosis. J Org Chem 2015; 80:6545-52. [PMID: 26035083 DOI: 10.1021/acs.joc.5b00455] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mycobactins are small-molecule iron chelators (siderophores) produced by Mycobacterium tuberculosis (Mtb) for iron mobilization. The bifunctional salicylate synthase MbtI catalyzes the first step of mycobactin biosynthesis through the conversion of the primary metabolite chorismate into salicylic acid via isochorismate. We report the design, synthesis, and biochemical evaluation of an inhibitor based on the putative transition state (TS) for the isochorismatase partial reaction of MbtI. The inhibitor mimics the hypothesized charge buildup at C-4 of chorismate in the TS as well as C-O bond formation at C-6. Another important design element of the inhibitor is replacement of the labile pyruvate side chain in chorismate with a stable C-linked propionate isostere. We developed a stereocontrolled synthesis of the highly functionalized cyclohexene inhibitor that features an asymmetric aldol reaction using a titanium enolate, diastereoselective Grignard addition to a tert-butanesulfinyl aldimine, and ring closing olefin metathesis as key steps.
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Affiliation(s)
- Zheng Liu
- †Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Feng Liu
- †Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street Southeast, Minneapolis, Minnesota 55455, United States
| | - Courtney C Aldrich
- †Department of Medicinal Chemistry, University of Minnesota, 308 Harvard Street Southeast, Minneapolis, Minnesota 55455, United States
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8
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Lamb AL. Breaking a pathogen's iron will: Inhibiting siderophore production as an antimicrobial strategy. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1054-70. [PMID: 25970810 DOI: 10.1016/j.bbapap.2015.05.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 04/29/2015] [Accepted: 05/06/2015] [Indexed: 12/24/2022]
Abstract
The rise of antibiotic resistance is a growing public health crisis. Novel antimicrobials are sought, preferably developing nontraditional chemical scaffolds that do not inhibit standard targets such as cell wall synthesis or the ribosome. Iron scavenging has been proposed as a viable target, because bacterial and fungal pathogens must overcome the nutritional immunity of the host to be virulent. This review highlights the recent work toward exploiting the biosynthetic enzymes of siderophore production for the design of next generation antimicrobials.
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Affiliation(s)
- Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS 66045, USA.
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9
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Meneely KM, Luo Q, Riley AP, Taylor B, Roy A, Stein RL, Prisinzano TE, Lamb AL. Expanding the results of a high throughput screen against an isochorismate-pyruvate lyase to enzymes of a similar scaffold or mechanism. Bioorg Med Chem 2014; 22:5961-9. [PMID: 25282647 DOI: 10.1016/j.bmc.2014.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 08/27/2014] [Accepted: 09/05/2014] [Indexed: 01/31/2023]
Abstract
Antibiotic resistance is a growing health concern, and new avenues of antimicrobial drug design are being actively sought. One suggested pathway to be targeted for inhibitor design is that of iron scavenging through siderophores. Here we present a high throughput screen to the isochorismate-pyruvate lyase of Pseudomonas aeruginosa, an enzyme required for the production of the siderophore pyochelin. Compounds identified in the screen are high nanomolar to low micromolar inhibitors of the enzyme and produce growth inhibition in PAO1 P. aeruginosa in the millimolar range under iron-limiting conditions. The identified compounds were also tested for enzymatic inhibition of Escherichia coli chorismate mutase, a protein of similar fold and similar chemistry, and of Yersinia enterocolitica salicylate synthase, a protein of differing fold but catalyzing the same lyase reaction. In both cases, subsets of the inhibitors from the screen were found to be inhibitory to enzymatic activity (mutase or synthase) in the micromolar range and capable of growth inhibition in their respective organisms (E. coli or Y. enterocolitica).
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Affiliation(s)
- Kathleen M Meneely
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045, United States
| | - Qianyi Luo
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045, United States
| | - Andrew P Riley
- Department of Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS 66045, United States
| | - Byron Taylor
- High Throughput Screening Facility, University of Kansas, 2034 Becker Dr, Lawrence, KS 66047, United States
| | - Anuradha Roy
- High Throughput Screening Facility, University of Kansas, 2034 Becker Dr, Lawrence, KS 66047, United States
| | - Ross L Stein
- High Throughput Screening Facility, University of Kansas, 2034 Becker Dr, Lawrence, KS 66047, United States
| | - Thomas E Prisinzano
- Department of Medicinal Chemistry, University of Kansas, 1251 Wescoe Hall Dr, Lawrence, KS 66045, United States
| | - Audrey L Lamb
- Department of Molecular Biosciences, University of Kansas, 1200 Sunnyside Ave, Lawrence, KS 66045, United States.
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10
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Hubrich F, Mordhorst S, Andexer JN. Cinnamic acid derivatives as inhibitors for chorismatases and isochorismatases. Bioorg Med Chem Lett 2013; 23:1477-81. [DOI: 10.1016/j.bmcl.2012.12.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 12/13/2012] [Accepted: 12/15/2012] [Indexed: 01/25/2023]
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11
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Chi G, Manos-Turvey A, O’Connor PD, Johnston JM, Evans GL, Baker EN, Payne RJ, Lott JS, Bulloch EMM. Implications of Binding Mode and Active Site Flexibility for Inhibitor Potency against the Salicylate Synthase from Mycobacterium tuberculosis. Biochemistry 2012; 51:4868-79. [DOI: 10.1021/bi3002067] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Gamma Chi
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | | | - Patrick D. O’Connor
- Auckland Cancer Society Research
Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Jodie M. Johnston
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Genevieve L. Evans
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Edward N. Baker
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Richard J. Payne
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - J. Shaun Lott
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Esther M. M. Bulloch
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
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12
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Camara D, Bisanz C, Barette C, Van Daele J, Human E, Barnard B, Van der Straeten D, Stove CP, Lambert WE, Douce R, Maréchal E, Birkholtz LM, Cesbron-Delauw MF, Dumas R, Rébeillé F. Inhibition of p-aminobenzoate and folate syntheses in plants and apicomplexan parasites by natural product rubreserine. J Biol Chem 2012; 287:22367-76. [PMID: 22577137 DOI: 10.1074/jbc.m112.365833] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Glutamine amidotransferase/aminodeoxychorismate synthase (GAT-ADCS) is a bifunctional enzyme involved in the synthesis of p-aminobenzoate, a central component part of folate cofactors. GAT-ADCS is found in eukaryotic organisms autonomous for folate biosynthesis, such as plants or parasites of the phylum Apicomplexa. Based on an automated screening to search for new inhibitors of folate biosynthesis, we found that rubreserine was able to inhibit the glutamine amidotransferase activity of the plant GAT-ADCS with an apparent IC(50) of about 8 μM. The growth rates of Arabidopsis thaliana, Toxoplasma gondii, and Plasmodium falciparum were inhibited by rubreserine with respective IC(50) values of 65, 20, and 1 μM. The correlation between folate biosynthesis and growth inhibition was studied with Arabidopsis and Toxoplasma. In both organisms, the folate content was decreased by 40-50% in the presence of rubreserine. In both organisms, the addition of p-aminobenzoate or 5-formyltetrahydrofolate in the external medium restored the growth for inhibitor concentrations up to the IC(50) value, indicating that, within this range of concentrations, rubreserine was specific for folate biosynthesis. Rubreserine appeared to be more efficient than sulfonamides, antifolate drugs known to inhibit the invasion and proliferation of T. gondii in human fibroblasts. Altogether, these results validate the use of the bifunctional GAT-ADCS as an efficient drug target in eukaryotic cells and indicate that the chemical structure of rubreserine presents interesting anti-parasitic (toxoplasmosis, malaria) potential.
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Affiliation(s)
- Djeneb Camara
- Laboratoire de Physiologie Cellulaire Végétale, Commissariat à l'Energie Atomique/CNRS UMR5168/INRA USC1200/Université Joseph Fourier Grenoble I, Institut de Recherches en Technologies et Sciences pour le Vivant, F-38054 Grenoble, France
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13
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Manos-Turvey A, Cergol KM, Salam NK, Bulloch EMM, Chi G, Pang A, Britton WJ, West NP, Baker EN, Lott JS, Payne RJ. Synthesis and evaluation of M. tuberculosis salicylate synthase (MbtI) inhibitors designed to probe plasticity in the active site. Org Biomol Chem 2012; 10:9223-36. [DOI: 10.1039/c2ob26736e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Vasan M, Neres J, Williams J, Wilson DJ, Teitelbaum AM, Remmel RP, Aldrich CC. Inhibitors of the salicylate synthase (MbtI) from Mycobacterium tuberculosis discovered by high-throughput screening. ChemMedChem 2011; 5:2079-87. [PMID: 21053346 DOI: 10.1002/cmdc.201000275] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A simple steady-state kinetic high-throughput assay was developed for the salicylate synthase MbtI from Mycobacterium tuberculosis, which catalyzes the first committed step of mycobactin biosynthesis. The mycobactins are small-molecule iron chelators produced by M. tuberculosis, and their biosynthesis has been identified as a promising target for the development of new antitubercular agents. The assay was miniaturized to a 384-well plate format and high-throughput screening was performed at the National Screening Laboratory for the Regional Centers of Excellence in Biodefense and Emerging Infectious Diseases (NSRB). Three classes of compounds were identified comprising the benzisothiazolones (class I), diarylsulfones (class II), and benzimidazole-2-thiones (class III). Each of these compound series was further pursued to investigate their biochemical mechanism and structure-activity relationships. Benzimidazole-2-thione 4 emerged as the most promising inhibitor owing to its potent reversible inhibition.
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Affiliation(s)
- Mahalakshmi Vasan
- Center for Drug Design, University of Minnesota, Minneapolis, 55455, USA
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