1
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Bague D, Wang R, Hodge D, Mikati MO, Roma JS, Boshoff HI, Dailey AL, Girma M, Couch RD, Odom John AR, Dowd CS. Inhibition of DXR in the MEP pathway with lipophilic N-alkoxyaryl FR900098 analogs. RSC Med Chem 2024; 15:2422-2439. [PMID: 39026652 PMCID: PMC11253873 DOI: 10.1039/d3md00642e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 05/22/2024] [Indexed: 07/20/2024] Open
Abstract
In Mycobacterium tuberculosis (Mtb) and Plasmodium falciparum (Pf), the methylerythritol phosphate (MEP) pathway is responsible for isoprene synthesis. This pathway and its products are vital to bacterial/parasitic metabolism and survival, and represent an attractive set of drug targets due to their essentiality in these pathogens but absence in humans. The second step in the MEP pathway is the conversion of 1-deoxy-d-xylulose-5-phosphate (DXP) to MEP and is catalyzed by 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR). Natural products fosmidomycin and FR900098 inhibit DXR, but are too polar to reach the desired target inside some cells, such as Mtb. Synthesized FR900098 analogs with lipophilic substitution in the position α to the phosphorous atom showed promise, resulting in increased activity against Mtb and Pf. Here, an α substitution, consisting of a 3,4-dichlorophenyl substituent, in combination with various O-linked alkylaryl substituents on the hydroxamate moiety is utilized in the synthesis of a novel series of FR900098 analogs. The purpose of the O-linked alkylaryl substituents is to further enhance DXR inhibition by extending the structure into the adjacent NADPH binding pocket, blocking the binding of both DXP and NADPH. Of the initial O-linked alkylaryl substituted analogs, compound 6e showed most potent activity against Pf parasites at 3.60 μM. Additional compounds varying the phenyl ring of 6e were synthesized. The most potent phosphonic acids, 6l and 6n, display nM activity against PfDXR and low μM activity against Pf parasites. Prodrugs of these compounds were less effective against Pf parasites but showed modest activity against Mtb cells. Data from this series of compounds suggests that this combination of substituents can be advantageous in designing a new generation of antimicrobials.
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Affiliation(s)
- Darean Bague
- Department of Chemistry, George Washington University Washington D.C. 20052 USA
| | - Ruiqin Wang
- Department of Chemistry, George Washington University Washington D.C. 20052 USA
| | - Dana Hodge
- Division of Infectious Diseases, Children's Hospital of Philadelphia Philadelphia PA 19104 USA
| | - Marwa O Mikati
- Department of Molecular Microbiology, Washington University School of Medicine St. Louis MO 63110 USA
| | - Jose S Roma
- Tuberculosis Research Section, LCIM, NIAID/NIH Bethesda MD 20892 USA
| | - Helena I Boshoff
- Tuberculosis Research Section, LCIM, NIAID/NIH Bethesda MD 20892 USA
| | - Allyson L Dailey
- Department of Chemistry and Biochemistry, George Mason University Fairfax VA 22030 USA
| | - Misgina Girma
- Department of Chemistry and Biochemistry, George Mason University Fairfax VA 22030 USA
| | - Robin D Couch
- Department of Chemistry and Biochemistry, George Mason University Fairfax VA 22030 USA
| | - Audrey R Odom John
- Division of Infectious Diseases, Children's Hospital of Philadelphia Philadelphia PA 19104 USA
- Department of Molecular Microbiology, Washington University School of Medicine St. Louis MO 63110 USA
| | - Cynthia S Dowd
- Department of Chemistry, George Washington University Washington D.C. 20052 USA
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2
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Rani N, Surolia A. Targeted suppression of MEP pathway genes DXS, IspD and IspF to explore the mycobacterial metabolism and survival. Int J Biol Macromol 2024; 272:132727. [PMID: 38823743 DOI: 10.1016/j.ijbiomac.2024.132727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 05/10/2024] [Accepted: 05/24/2024] [Indexed: 06/03/2024]
Abstract
Due to the uniqueness and essentiality of MEP pathway for the synthesis of crucial metabolites- isoprenoids, hopanoids, menaquinone etc. in mycobacterium, enzymes of this pathway are considered promising anti-tubercular drug targets. In the present study we seek to understand the consequences of downregulation of three of the essential genes- DXS, IspD, and IspF of MEP pathway using CRISPRi approach combined with transcriptomics in Mycobacterium smegmatis. Conditional knock down of either DXS or IspD or IspF gene showed strong bactericidal effect and a profound change in colony morphology. Impaired MEP pathway due to downregulation of these genes increased the susceptibility to frontline anti-tubercular drugs. Further, reduced EtBr accumulation in all the knock down strains in the presence and absence of efflux inhibitor indicated altered cell wall topology. Subsequently, transcriptional analysis validated by qRT-PCR of +154DXS, +128IspD, +104IspF strains showed that modifying the expression of these MEP pathway enzymes affects the regulation of mycobacterial core components. Among the DEGs, expression of small and large ribosomal binding proteins (rpsL, rpsJ, rplN, rplX, rplM, rplS, etc), essential protein translocases (secE, secY and infA, infC), transcriptional regulator (CarD and SigB) and metabolic enzymes (acpP, hydA, ald and fabD) were significantly depleted causing the bactericidal effect. However, mycobacteria survived under these damaging conditions by upregulating mostly the genes needed for the repair of DNA damage (DNA polymerase IV, dinB), synthesis of essential metabolites (serB, LeuA, atpD) and those strengthening the cell wall integrity (otsA, murA, D-alanyl-D-alanine dipeptidase etc.).
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Affiliation(s)
- Nidhi Rani
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
| | - Avadhesha Surolia
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India; Dr.Reddy's Institute of Life Science, Hyderabad 500046, India.
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3
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Islam S, Salekeen R, Ashraf A. Computational screening of natural MtbDXR inhibitors for novel anti-tuberculosis compound discovery. J Biomol Struct Dyn 2024; 42:3593-3603. [PMID: 37272886 DOI: 10.1080/07391102.2023.2218933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023]
Abstract
DXR (1-deoxy-d-xylulose-5-phosphate reductoisomerase) is an essential enzyme in the Methylerythritol 4-phosphate (MEP) pathway, which is used by M. tuberculosis and a few other pathogens. This essential enzyme in the isoprenoid synthesis pathway has been previously reported as an important target for antibiotic drug design. However, till now, there is no record of any drug-like safe molecule to inhibit MtbDXR. Numerous plant species have been traditionally used for tuberculosis therapies. In this study, we selected six plant species with anti-tubercular properties. The chemoinformatic screening was performed on 352 phytochemicals from those plants against the MtbDXR protein. After molecular docking analysis, we filtered the top five compounds, CID: 5280443 (Apigenin), CID: 3220 (Emodin), CID: 5280863 (Kaempferol), CID: 5280445 (Luteolin), and CID: 6101979 (beta-Hydroxychalcone), based on binding affinity. Molecular dynamics simulations disclosed the stability of the compounds at the active site of the proteins. Finally, in silico ADME and toxicity evaluations confirmed the compounds to be effective and safe for oral administration. Thus, our findings identified three drug-like safe molecules- Apigenin, Kaempferol, and beta-Hydroxychalcone, that showed good stability in the protein's active site. The results of this computational approach may act as an initial instruction for future in vitro and in vivo testing to identify natural drug-like compounds to treat tuberculosis.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sabrina Islam
- Biotechnology and Genetic Engineering Discipline, Life Science School, Khulna University, Khulna, Bangladesh
| | - Rahagir Salekeen
- Biotechnology and Genetic Engineering Discipline, Life Science School, Khulna University, Khulna, Bangladesh
| | - Ayesha Ashraf
- Biotechnology and Genetic Engineering Discipline, Life Science School, Khulna University, Khulna, Bangladesh
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4
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Wang X, Edwards RL, Ball HS, Heidel KM, Brothers RC, Johnson C, Haymond A, Girma M, Dailey A, Roma JS, Boshoff HI, Osbourn DM, Meyers MJ, Couch RD, Odom John AR, Dowd CS. MEPicides: α,β-unsaturated Fosmidomycin N-Acyl Analogs as Efficient Inhibitors of Plasmodium falciparum 1-Deoxy-d-xylulose-5-phosphate reductoisomerase. ACS Infect Dis 2023; 9:1387-1395. [PMID: 37310810 PMCID: PMC10880585 DOI: 10.1021/acsinfecdis.3c00132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Malaria, a mosquito-borne disease caused by several parasites of the Plasmodium genus, remains a huge threat to global public health. There are an estimated 0.5 million malaria deaths each year, mostly among African children. Unlike humans, Plasmodium parasites and a number of important pathogenic bacteria employ the methyl erythritol phosphate (MEP) pathway for isoprenoid synthesis. Thus, the MEP pathway represents a promising set of drug targets for antimalarial and antibacterial compounds. Here, we present new unsaturated MEPicide inhibitors of 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), the second enzyme of the MEP pathway. A number of these compounds have demonstrated robust inhibition of Plasmodium falciparum DXR, potent antiparasitic activity, and low cytotoxicity against HepG2 cells. Parasites treated with active compounds are rescued by isopentenyl pyrophosphate, the product of the MEP pathway. With higher levels of DXR substrate, parasites acquire resistance to active compounds. These results further confirm the on-target inhibition of DXR in parasites by the inhibitors. Stability in mouse liver microsomes is high for the phosphonate salts, but remains a challenge for the prodrugs. Taken together, the potent activity and on-target mechanism of action of this series further validate DXR as an antimalarial drug target and the α,β-unsaturation moiety as an important structural component.
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Affiliation(s)
- Xu Wang
- Department of Chemistry, George Washington University, Washington, District of Columbia 20052, United States
| | - Rachel L Edwards
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Haley S Ball
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Kenneth M Heidel
- Department of Chemistry, George Washington University, Washington, District of Columbia 20052, United States
| | - Robert C Brothers
- Department of Chemistry, George Washington University, Washington, District of Columbia 20052, United States
| | - Claire Johnson
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Amanda Haymond
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Misgina Girma
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Allyson Dailey
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Jose Santinni Roma
- Tuberculosis Research Section, LCIM, NIAID/NIH, Bethesda, Maryland 20892, United States
| | - Helena I Boshoff
- Tuberculosis Research Section, LCIM, NIAID/NIH, Bethesda, Maryland 20892, United States
| | - Damon M Osbourn
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Marvin J Meyers
- Department of Chemistry, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Robin D Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20110, United States
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Cynthia S Dowd
- Department of Chemistry, George Washington University, Washington, District of Columbia 20052, United States
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5
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Over 40 Years of Fosmidomycin Drug Research: A Comprehensive Review and Future Opportunities. Pharmaceuticals (Basel) 2022; 15:ph15121553. [PMID: 36559004 PMCID: PMC9782300 DOI: 10.3390/ph15121553] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022] Open
Abstract
To address the continued rise of multi-drug-resistant microorganisms, the development of novel drugs with new modes of action is urgently required. While humans biosynthesize the essential isoprenoid precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) via the established mevalonate pathway, pathogenic protozoa and certain pathogenic eubacteria use the less well-known methylerythritol phosphate pathway for this purpose. Important pathogens using the MEP pathway are, for example, Plasmodium falciparum, Mycobacterium tuberculosis, Pseudomonas aeruginosa and Escherichia coli. The enzymes of that pathway are targets for antiinfective drugs that are exempt from target-related toxicity. 2C-Methyl-D-erythritol 4-phosphate (MEP), the second enzyme of the non-mevalonate pathway, has been established as the molecular target of fosmidomycin, an antibiotic that has so far failed to be approved as an anti-infective drug. This review describes the development and anti-infective properties of a wide range of fosmidomycin derivatives synthesized over the last four decades. Here we discuss the DXR inhibitor pharmacophore, which comprises a metal-binding group, a phosphate or phosphonate moiety and a connecting linker. Furthermore, non-fosmidomycin-based DXRi, bisubstrate inhibitors and several prodrug concepts are described. A comprehensive structure-activity relationship (SAR) of nearly all inhibitor types is presented and some novel opportunities for further drug development of DXR inhibitors are discussed.
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6
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Ball HS, Girma MB, Zainab M, Soojhawon I, Couch RD, Noble SM. Characterization and Inhibition of 1-Deoxy-d-Xylulose 5-Phosphate Reductoisomerase: A Promising Drug Target in Acinetobacter baumannii and Klebsiella pneumoniae. ACS Infect Dis 2021; 7:2987-2998. [PMID: 34672535 PMCID: PMC8594541 DOI: 10.1021/acsinfecdis.1c00132] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The ESKAPE pathogens
comprise a group of multidrug-resistant bacteria
that are the leading cause of nosocomial infections worldwide. The
prevalence of antibiotic resistant strains and the relative ease by
which bacteria acquire resistance genes highlight the continual need
for the development of novel antibiotics against new drug targets.
The methylerythritol phosphate (MEP) pathway is an attractive target
for the development of new antibiotics. The MEP pathway governs the
synthesis of isoprenoids, which are key lipid precursors for vital
cell components such as ubiquinone and bacterial hopanoids. Additionally,
the MEP pathway is entirely distinct from the corresponding mammalian
pathway, the mevalonic acid (MVA) pathway, making the first committed
enzyme of the MEP pathway, 1-deoxy-d-xylulose 5-phosphate
reductoisomerase (IspC), an attractive target for antibiotic development.
To facilitate drug development against two of the ESKAPE pathogens, Acinetobacter baumannii and Klebsiella
pneumoniae, we cloned, expressed, purified, and characterized
IspC from these two Gram-negative bacteria. Enzyme inhibition assays
using IspC from these two pathogens, and compounds fosmidomycin and
FR900098, indicate IC50 values ranging from 19.5–45.5
nM. Antimicrobial susceptibility tests with these inhibitors reveal
that A. baumannii is susceptible to
FR900098, whereas K. pneumoniae is
susceptible to both compounds. Finally, to facilitate structure-based
drug design of inhibitors targeting A. baumannii IspC, we determined the 2.5 Å crystal structure of IspC from A. baumannii in complex with inhibitor FR900098,
and cofactors NADPH and magnesium.
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Affiliation(s)
- Haley S. Ball
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20109, United States of America
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Springs, Maryland 20910, United States of America
| | - Misgina B. Girma
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20109, United States of America
| | - Mosufa Zainab
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20109, United States of America
| | - Iswarduth Soojhawon
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Springs, Maryland 20910, United States of America
| | - Robin D. Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia 20109, United States of America
| | - Schroeder M. Noble
- Wound Infections Department, Bacterial Diseases Branch, Center for Infectious Diseases Research, Walter Reed Army Institute of Research, Silver Springs, Maryland 20910, United States of America
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7
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Girma M, Ball HS, Wang X, Brothers RC, Jackson ER, Meyers MJ, Dowd CS, Couch RD. Mechanism of Action of N-Acyl and N-Alkoxy Fosmidomycin Analogs: Mono- and Bisubstrate Inhibition of IspC from Plasmodium falciparum, a Causative Agent of Malaria. ACS OMEGA 2021; 6:27630-27639. [PMID: 34722963 PMCID: PMC8552233 DOI: 10.1021/acsomega.1c01711] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 09/09/2021] [Indexed: 06/01/2023]
Abstract
Malaria is a global health threat that requires immediate attention. Malaria is caused by the protozoan parasite Plasmodium, the most severe form of which is Plasmodium falciparum. The methylerythritol phosphate (MEP) pathway of isoprenoid biosynthesis is essential to the survival of many human pathogens, including P. falciparum, but is absent in humans, and thus shows promise as a new antimalarial drug target. The enzyme 1-deoxy-d-xylulose 5-phosphate reductoisomerase (IspC) catalyzes the first committed step in the MEP pathway. In addition to a divalent cation (Mg2+), the enzyme requires the substrates 1-deoxy-D-xylulose 5-phosphate (DXP) and NADPH to catalyze its reaction. We designed N-alkoxy and N-acyl fosmidomycin analogs to inhibit the activity of P. falciparum IspC in a bisubstrate manner. Enzyme assays reveal that the N-alkoxy fosmidomycin analogs have a competitive mode of inhibition relative to both the DXP- and NADPH-binding sites, confirming a bisubstrate mode of inhibition. In contrast, the N-acyl fosmidomycin analogs demonstrate competitive inhibition with respect to DXP but uncompetitive inhibition with respect to NADPH, indicating monosubstrate inhibitory activity. Our results will have a positive impact on the discovery of novel antimalarial drugs.
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Affiliation(s)
- Misgina
B. Girma
- Department
of Chemistry and Biochemistry, George Mason
University, Manassas, Virginia 20110, United States
| | - Haley S. Ball
- Department
of Chemistry and Biochemistry, George Mason
University, Manassas, Virginia 20110, United States
| | - Xu Wang
- Progenra
Inc., Malvern, Pennsylvania 19355, United States
| | - Robert C. Brothers
- Department
of Chemistry, The George Washington University, Washington, District of
Columbia 20052, United
States
| | - Emily R. Jackson
- Department
of Chemistry, The George Washington University, Washington, District of
Columbia 20052, United
States
| | - Marvin J. Meyers
- Department
of Chemistry, Saint Louis University, Saint Louis, Missouri 63103, United States
| | - Cynthia S. Dowd
- Department
of Chemistry, The George Washington University, Washington, District of
Columbia 20052, United
States
| | - Robin D. Couch
- Department
of Chemistry and Biochemistry, George Mason
University, Manassas, Virginia 20110, United States
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8
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Miller JJ, Shah IT, Hatten J, Barekatain Y, Mueller EA, Moustafa AM, Edwards RL, Dowd CS, Planet PJ, Muller FL, Jez JM, Odom John AR. Structure-guided microbial targeting of antistaphylococcal prodrugs. eLife 2021; 10:66657. [PMID: 34279224 PMCID: PMC8318587 DOI: 10.7554/elife.66657] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 07/16/2021] [Indexed: 01/07/2023] Open
Abstract
Carboxy ester prodrugs are widely employed to increase oral absorption and potency of phosphonate antibiotics. Prodrugging can mask problematic chemical features that prevent cellular uptake and may enable tissue-specific compound delivery. However, many carboxy ester promoieties are rapidly hydrolyzed by serum esterases, limiting their therapeutic potential. While carboxy ester-based prodrug targeting is feasible, it has seen limited use in microbes as microbial esterase-specific promoieties have not been described. Here we identify the bacterial esterases, GloB and FrmB, that activate carboxy ester prodrugs in Staphylococcus aureus. Additionally, we determine the substrate specificities for FrmB and GloB and demonstrate the structural basis of these preferences. Finally, we establish the carboxy ester substrate specificities of human and mouse sera, ultimately identifying several promoieties likely to be serum esterase-resistant and microbially labile. These studies will enable structure-guided design of antistaphylococcal promoieties and expand the range of molecules to target staphylococcal pathogens.
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Affiliation(s)
- Justin J Miller
- Department of Pediatrics, Washington University School of Medicine, St. Louis, United States.,Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Ishaan T Shah
- Department of Pediatrics, Washington University School of Medicine, St. Louis, United States
| | - Jayda Hatten
- Department of Pediatrics, Washington University School of Medicine, St. Louis, United States
| | - Yasaman Barekatain
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Elizabeth A Mueller
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Ahmed M Moustafa
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, United States
| | - Rachel L Edwards
- Department of Pediatrics, Washington University School of Medicine, St. Louis, United States
| | - Cynthia S Dowd
- Department of Chemistry, The George Washington University, Washington, United States
| | - Paul J Planet
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, United States
| | - Florian L Muller
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, United States
| | - Joseph M Jez
- Department of Biology, Washington University in St. Louis, St. Louis, United States
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, United States.,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Children's Hospital of Philadelphia, Philadelphia, United States.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, United States
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9
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Choudhury C, Bhardwaj A. Hybrid Dynamic Pharmacophore Models as Effective Tools to Identify Novel Chemotypes for Anti-TB Inhibitor Design: A Case Study With Mtb-DapB. Front Chem 2020; 8:596412. [PMID: 33425853 PMCID: PMC7793862 DOI: 10.3389/fchem.2020.596412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 10/28/2020] [Indexed: 11/13/2022] Open
Abstract
Antimicrobial resistance (AMR) is one of the most serious global public health threats as it compromises the successful treatment of deadly infectious diseases like tuberculosis. New therapeutics are constantly needed but it takes a long time and is expensive to explore new biochemical space. One way to address this issue is to repurpose the validated targets and identify novel chemotypes that can simultaneously bind to multiple binding pockets of these targets as a new lead generation strategy. This study reports such a strategy, dynamic hybrid pharmacophore model (DHPM), which represents the combined interaction features of different binding pockets contrary to the conventional approaches, where pharmacophore models are generated from single binding sites. We have considered Mtb-DapB, a validated mycobacterial drug target, as our model system to explore the effectiveness of DHPMs to screen novel unexplored compounds. Mtb-DapB has a cofactor binding site (CBS) and an adjacent substrate binding site (SBS). Four different model systems of Mtb-DapB were designed where, either NADPH/NADH occupies CBS in presence/absence of an inhibitor 2, 6-PDC in the adjacent SBS. Two more model systems were designed, where 2, 6-PDC was linked to NADPH and NADH to form hybrid molecules. The six model systems were subjected to 200 ns molecular dynamics simulations and trajectories were analyzed to identify stable ligand-receptor interaction features. Based on these interactions, conventional pharmacophore models (CPM) were generated from the individual binding sites while DHPMs were created from hybrid-molecules occupying both binding sites. A huge library of 1,563,764 publicly available molecules were screened by CPMs and DHPMs. The screened hits obtained from both types of models were compared based on their Hashed binary molecular fingerprints and 4-point pharmacophore fingerprints using Tanimoto, Cosine, Dice and Tversky similarity matrices. Molecules screened by DHPM exhibited significant structural diversity, better binding strength and drug like properties as compared to the compounds screened by CPMs indicating the efficiency of DHPM to explore new chemical space for anti-TB drug discovery. The idea of DHPM can be applied for a wide range of mycobacterial or other pathogen targets to venture into unexplored chemical space.
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Affiliation(s)
- Chinmayee Choudhury
- Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh, India
| | - Anshu Bhardwaj
- Bioinformatics Centre, Council of Scientific and Industrial Research-Institute of Microbial Technology, Chandigarh, India
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10
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Non-hydroxamate inhibitors of 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR): A critical review and future perspective. Eur J Med Chem 2020; 213:113055. [PMID: 33303239 DOI: 10.1016/j.ejmech.2020.113055] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/18/2020] [Accepted: 11/21/2020] [Indexed: 12/22/2022]
Abstract
1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) catalyzes the second step of the non-mevalonate (or MEP) pathway that functions in several organisms and plants for the synthesis of isoprenoids. DXR is essential for the survival of multiple pathogenic bacteria/parasites, including those that cause tuberculosis and malaria in humans. DXR function is inhibited by fosmidomycin (1), a natural product, which forms a chelate with the active site divalent metal (Mg2+/Mn2+) through its hydroxamate metal-binding group (MBG). Most of the potent DXR inhibitors are structurally similar to 1 and retain hydroxamate despite the unfavourable pharmacokinetic and toxicity profile of the latter. We provide our perspective on the lack of non-hydroxamate DXR inhibitors. We also highlight the fundamental flaws in the design of MBG in these molecules, primarily responsible for their failure to inhibit DXR. We also suggest that for designing next-generation non-hydroxamate DXR inhibitors, approaches followed for other metalloenzymes targets may be exploited.
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11
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Mikati MO, Miller JJ, Osbourn DM, Barekatain Y, Ghebremichael N, Shah IT, Burnham CAD, Heidel KM, Yan VC, Muller FL, Dowd CS, Edwards RL, Odom John AR. Antimicrobial Prodrug Activation by the Staphylococcal Glyoxalase GloB. ACS Infect Dis 2020; 6:3064-3075. [PMID: 33118347 PMCID: PMC8543975 DOI: 10.1021/acsinfecdis.0c00582] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
With the rising prevalence of multidrug resistance, there is an urgent need to develop novel antibiotics. Many putative antibiotics demonstrate promising in vitro potency but fail in vivo due to poor drug-like qualities (e.g., serum half-life, oral absorption, solubility, and toxicity). These drug-like properties can be modified through the addition of chemical protecting groups, creating "prodrugs" that are activated prior to target inhibition. Lipophilic prodrugging techniques, including the attachment of a pivaloyloxymethyl group, have garnered attention for their ability to increase cellular permeability by masking charged residues and the relative ease of the chemical prodrugging process. Unfortunately, pivaloyloxymethyl prodrugs are rapidly activated by human sera, rendering any membrane permeability qualities absent during clinical treatment. Identification of the bacterial prodrug activation pathway(s) will allow for the development of host-stable and microbe-targeted prodrug therapies. Here, we use two zoonotic staphylococcal species, Staphylococcus schleiferi and S. pseudintermedius, to establish the mechanism of carboxy ester prodrug activation. Using a forward genetic screen, we identify a conserved locus in both species encoding the enzyme hydroxyacylglutathione hydrolase (GloB), whose loss-of-function confers resistance to carboxy ester prodrugs. We enzymatically characterize GloB and demonstrate that it is a functional glyoxalase II enzyme, which has the capacity to activate carboxy ester prodrugs. As GloB homologues are both widespread and diverse in sequence, our findings suggest that GloB may be a useful mechanism for developing species- or genus-level prodrug targeting strategies.
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Affiliation(s)
- Marwa O Mikati
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Justin J Miller
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Damon M Osbourn
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Yasaman Barekatain
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Naomi Ghebremichael
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Ishaan T Shah
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Carey-Ann D Burnham
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Kenneth M Heidel
- Department of Chemistry, The George Washington University, Washington, DC 20052, United States
| | - Victoria C Yan
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Florian L Muller
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas 77054, United States
| | - Cynthia S Dowd
- Department of Chemistry, The George Washington University, Washington, DC 20052, United States
| | - Rachel L Edwards
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| | - Audrey R Odom John
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, United States
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12
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Synthesis and Antiplasmodial Activity of Novel Fosmidomycin Derivatives and Conjugates with Artemisinin and Aminochloroquinoline. Molecules 2020; 25:molecules25204858. [PMID: 33096817 PMCID: PMC7587979 DOI: 10.3390/molecules25204858] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 11/17/2022] Open
Abstract
Malaria, despite many efforts, remains among the most problematic infectious diseases worldwide, mainly due to the development of drug resistance by Plasmodium falciparum. The antibiotic fosmidomycin (FSM) is also known for its antimalarial activity by targeting the non-mevalonate isoprenoid synthesis pathway, which is essential for the malaria parasites but is absent in mammalians. In this study, we synthesized and evaluated against the chloroquine-resistant P. falciparum FcB1/Colombia strain, a series of FSM analogs, derivatives, and conjugates with other antimalarial agents, such as artemisinin (ART) and aminochloroquinoline (ACQ). The biological evaluation revealed four new compounds with higher antimalarial activity than FSM: two FSM-ACQ derivatives and two FSM-ART conjugates, with 3.5-5.4 and 41.5-23.1 times more potent activities than FSM, respectively.
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13
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Heidel KM, Dowd CS. Phosphonate prodrugs: an overview and recent advances. Future Med Chem 2019; 11:1625-1643. [PMID: 31469328 PMCID: PMC6722485 DOI: 10.4155/fmc-2018-0591] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 03/29/2019] [Indexed: 01/04/2023] Open
Abstract
Phosphonates, often used as isosteric replacements for phosphates, can provide important interactions with an enzyme. Due to their high charge at physiological pH, however, permeation into cells can be a challenge. Protecting phosphonates as prodrugs has shown promise in drug delivery. Thus, a variety of structures and cleavage/activation mechanisms exist, enabling release of the active compound. This review describes the structural diversity of these pro-moieties, relevant cleavage mechanisms and recent advances in the design of phosphonate prodrugs.
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Affiliation(s)
- Kenneth M Heidel
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
| | - Cynthia S Dowd
- Department of Chemistry, George Washington University, Washington, DC 20052, USA
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14
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Phosphonodiamidate prodrugs of N-alkoxy analogs of a fosmidomycin surrogate as antimalarial and antitubercular agents. Bioorg Med Chem Lett 2019; 29:1051-1053. [PMID: 30857749 DOI: 10.1016/j.bmcl.2019.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/04/2019] [Accepted: 03/06/2019] [Indexed: 11/23/2022]
Abstract
A series of N-alkoxy analogs of a l-leucine ethyl ester phosphonodiamidate prodrug of a fosmidomycin surrogate were synthesized and investigated for their ability to inhibit in vitro growth of P. falciparum and M. tuberculosis. These compounds originate by merging a previously reported successful phosphonate derivatisation with favorable modifications of the hydroxamate moiety. None of the synthesized compounds showed enhanced activity against either P. falciparum or M. tuberculosis in comparison with the parent free hydroxamate analog.
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15
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Wang X, Edwards RL, Ball H, Johnson C, Haymond A, Girma M, Manikkam M, Brothers RC, McKay KT, Arnett SD, Osbourn DM, Alvarez S, Boshoff HI, Meyers MJ, Couch RD, Odom John AR, Dowd CS. MEPicides: α,β-Unsaturated Fosmidomycin Analogues as DXR Inhibitors against Malaria. J Med Chem 2018; 61:8847-8858. [PMID: 30192536 DOI: 10.1021/acs.jmedchem.8b01026] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Severe malaria due to Plasmodium falciparum remains a significant global health threat. DXR, the second enzyme in the MEP pathway, plays an important role to synthesize building blocks for isoprenoids. This enzyme is a promising drug target for malaria due to its essentiality as well as its absence in humans. In this study, we designed and synthesized a series of α,β-unsaturated analogues of fosmidomycin, a natural product that inhibits DXR in P. falciparum. All compounds were evaluated as inhibitors of P. falciparum. The most promising compound, 18a, displays on-target, potent inhibition against the growth of P. falciparum (IC50 = 13 nM) without significant inhibition of HepG2 cells (IC50 > 50 μM). 18a was also tested in a luciferase-based Plasmodium berghei mouse model of malaria and showed exceptional in vivo efficacy. Together, the data support MEPicide 18a as a novel, potent, and promising drug candidate for the treatment of malaria.
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Affiliation(s)
- Xu Wang
- Department of Chemistry , George Washington University , Washington D.C. 20052 , United States
| | - Rachel L Edwards
- Department of Pediatrics , Washington University School of Medicine, Washington University , St. Louis , Missouri 63110 , United States
| | - Haley Ball
- Department of Chemistry and Biochemistry , George Mason University , Manassas , Virginia 20110 , United States
| | - Claire Johnson
- Department of Chemistry and Biochemistry , George Mason University , Manassas , Virginia 20110 , United States
| | - Amanda Haymond
- Department of Chemistry and Biochemistry , George Mason University , Manassas , Virginia 20110 , United States
| | - Misgina Girma
- Department of Chemistry and Biochemistry , George Mason University , Manassas , Virginia 20110 , United States
| | - Michelle Manikkam
- Tuberculosis Research Section, LCIM , NIAID/NIH , Bethesda , Maryland 20892 , United States
| | - Robert C Brothers
- Department of Chemistry , George Washington University , Washington D.C. 20052 , United States
| | - Kyle T McKay
- Department of Chemistry , George Washington University , Washington D.C. 20052 , United States
| | - Stacy D Arnett
- Department of Pharmacology and Physiology , Saint Louis University , St. Louis , Missouri 63104 , United States
| | - Damon M Osbourn
- Department of Molecular Microbiology and Immunology , Saint Louis University , St. Louis , Missouri 63104 , United States
| | - Sophie Alvarez
- Proteomics & Metabolomics Facility, Center for Biotechnology, Department of Agronomy and Horticulture , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Helena I Boshoff
- Tuberculosis Research Section, LCIM , NIAID/NIH , Bethesda , Maryland 20892 , United States
| | - Marvin J Meyers
- Department of Pharmacology and Physiology , Saint Louis University , St. Louis , Missouri 63104 , United States.,Department of Chemistry , Saint Louis University , St. Louis , Missouri 63103 , United States
| | - Robin D Couch
- Department of Chemistry and Biochemistry , George Mason University , Manassas , Virginia 20110 , United States
| | - Audrey R Odom John
- Department of Pediatrics , Washington University School of Medicine, Washington University , St. Louis , Missouri 63110 , United States
| | - Cynthia S Dowd
- Department of Chemistry , George Washington University , Washington D.C. 20052 , United States
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16
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Wang X, Dowd CS. The Methylerythritol Phosphate Pathway: Promising Drug Targets in the Fight against Tuberculosis. ACS Infect Dis 2018; 4:278-290. [PMID: 29390176 DOI: 10.1021/acsinfecdis.7b00176] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is a severe infectious disease in need of new chemotherapies especially for drug-resistant cases. To meet the urgent requirement of new TB drugs with novel modes of action, the TB research community has been validating numerous targets from several biosynthetic pathways. The methylerythritol phosphate (MEP) pathway is utilized by Mtb for the biosynthesis of isopentenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate (DMAPP), the universal five-carbon building blocks of isoprenoids. While being a common biosynthetic pathway in pathogens, the MEP pathway is completely absent in humans. Due to its unique presence in pathogens as well as the essentiality of the MEP pathway in Mtb, the enzymes in this pathway are promising targets for the development of new drugs against tuberculosis. In this Review, we discuss three enzymes in the MEP pathway: 1-deoxy-d-xylulose-5-phosphate synthase (DXS), 1-deoxy-d-xylulose-5-phosphate reductoisomerase (IspC/DXR), and 2 C-methyl-d-erythritol 2,4-cyclodiphosphate synthase (IspF), which appear to be the most promising antitubercular drug targets. Structural and mechanistic features of these enzymes are reviewed, as well as selected inhibitors that show promise as antitubercular agents.
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Affiliation(s)
- Xu Wang
- Department of Chemistry, George Washington University, 800 22nd Street NW, Washington, D.C. 20052, United States
| | - Cynthia S. Dowd
- Department of Chemistry, George Washington University, 800 22nd Street NW, Washington, D.C. 20052, United States
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17
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Design, synthesis, and evaluation of substituted nicotinamide adenine dinucleotide (NAD +) synthetase inhibitors as potential antitubercular agents. Bioorg Med Chem Lett 2017; 27:4426-4430. [PMID: 28827112 DOI: 10.1016/j.bmcl.2017.08.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 08/05/2017] [Accepted: 08/07/2017] [Indexed: 11/20/2022]
Abstract
Nicotinamide adenine dinucleotide (NAD+) synthetase catalyzes the last step in NAD+ biosynthesis. Depletion of NAD+ is bactericidal for both active and dormant Mycobacterium tuberculosis (Mtb). By inhibiting NAD+ synthetase (NadE) from Mtb, we expect to eliminate NAD+ production which will result in cell death in both growing and nonreplicating Mtb. NadE inhibitors have been investigated against various pathogens, but few have been tested against Mtb. Here, we report on the expansion of a series of urea-sulfonamides, previously reported by Brouillette et al. Guided by docking studies, substituents on a terminal phenyl ring were varied to understand the structure-activity-relationships of substituents on this position. Compounds were tested as inhibitors of both recombinant Mtb NadE and Mtb whole cells. While the parent compound displayed very weak inhibition against Mtb NadE (IC50=1000µM), we observed up to a 10-fold enhancement in potency after optimization. Replacement of the 3,4-dichloro group on the phenyl ring of the parent compound with 4-nitro yielded 4f, the most potent compound of the series with an IC50 value of 90µM against Mtb NadE. Our modeling results show that these urea-sulfonamides potentially bind to the intramolecular ammonia tunnel, which transports ammonia from the glutaminase domain to the active site of the enzyme. This hypothesis is supported by data showing that, even when treated with potent inhibitors, NadE catalysis is restored when treated with exogenous ammonia. Most of these compounds also inhibited Mtb cell growth with MIC values of 19-100µg/mL. These results improve our understanding of the SAR of the urea-sulfonamides, their mechanism of binding to the enzyme, and of Mtb NadE as a potential antitubercular drug target.
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18
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San Jose G, Jackson ER, Haymond A, Johny C, Edwards RL, Wang X, Brothers RC, Edelstein EK, Odom AR, Boshoff HI, Couch RD, Dowd CS. Structure-Activity Relationships of the MEPicides: N-Acyl and O-Linked Analogs of FR900098 as Inhibitors of Dxr from Mycobacterium tuberculosis and Yersinia pestis. ACS Infect Dis 2016; 2:923-935. [PMID: 27676224 PMCID: PMC5266543 DOI: 10.1021/acsinfecdis.6b00125] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite continued research efforts, the threat of drug resistance from a variety of bacteria continues to plague clinical communities. Discovery and validation of novel biochemical targets will facilitate development of new drugs to combat these organisms. The methylerythritol phosphate (MEP) pathway to make isoprene units is a biosynthetic pathway essential to many bacteria. We and others have explored inhibitors of the MEP pathway as novel antibacterial agents. Mycobacterium tuberculosis, the causative agent of tuberculosis, and Yersinia pestis, resulting in the plague or "black death", both rely on the MEP pathway for isoprene production. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (Dxr) catalyzes the first committed step in the MEP pathway. We examined two series of Dxr inhibitors based on the parent structure of the retrohydroxamate natural product FR900098. The compounds contain either an extended N-acyl or O-linked alkyl/aryl group and are designed to act as bisubstrate inhibitors of the enzyme. While nearly all of the compounds inhibited both Mtb and Yp Dxr to some extent, compounds generally displayed more potent inhibition against the Yp homologue, with the best analogs displaying nanomolar IC50 values. In bacterial growth inhibition assays, the phosphonic acids generally resulted in poor antibacterial activity, likely a reflection of inadequate permeability. Accordingly, diethyl and dipivaloyloxymethyl (POM) prodrug esters of these compounds were made. While the added lipophilicity did not enhance Yersinia activity, the compounds showed significantly improved antitubercular activities. The most potent compounds have Mtb MIC values of 3-12 μg/mL. Taken together, we have uncovered two series of analogs that potently inhibit Dxr homologues from Mtb and Yp. These inhibitors of the MEP pathway, termed MEPicides, serve as leads for future analog development.
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Affiliation(s)
- Géraldine San Jose
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
| | - Emily R. Jackson
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
| | - Amanda Haymond
- 10900 University Boulevard, Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110 USA
| | - Chinchu Johny
- 10900 University Boulevard, Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110 USA
| | - Rachel L. Edwards
- 660 S Euclid Avenue, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Xu Wang
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
| | - R. Carl Brothers
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
| | - Emma K. Edelstein
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
| | - Audrey R. Odom
- 660 S Euclid Avenue, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Helena I. Boshoff
- 9000 Rockville Pike, Tuberculosis Research Section, LCID, NIAID/NIH, Bethesda, MD 20892 USA
| | - Robin D. Couch
- 10900 University Boulevard, Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110 USA
| | - Cynthia S. Dowd
- 800 22 Street NW, Department of Chemistry, George Washington University, Washington DC 20052 USA
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19
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Masini T, Hirsch AKH. Development of Inhibitors of the 2C-Methyl-d-erythritol 4-Phosphate (MEP) Pathway Enzymes as Potential Anti-Infective Agents. J Med Chem 2014; 57:9740-63. [DOI: 10.1021/jm5010978] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Tiziana Masini
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh
7, NL-9747
AG Groningen, The Netherlands
| | - Anna K. H. Hirsch
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh
7, NL-9747
AG Groningen, The Netherlands
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20
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Haymond A, Johny C, Dowdy T, Schweibenz B, Villarroel K, Young R, Mantooth CJ, Patel T, Bases J, Jose GS, Jackson ER, Dowd CS, Couch RD. Kinetic characterization and allosteric inhibition of the Yersinia pestis 1-deoxy-D-xylulose 5-phosphate reductoisomerase (MEP synthase). PLoS One 2014; 9:e106243. [PMID: 25171339 PMCID: PMC4149570 DOI: 10.1371/journal.pone.0106243] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 07/29/2014] [Indexed: 11/19/2022] Open
Abstract
The methylerythritol phosphate (MEP) pathway found in many bacteria governs the synthesis of isoprenoids, which are crucial lipid precursors for vital cell components such as ubiquinone. Because mammals synthesize isoprenoids via an alternate pathway, the bacterial MEP pathway is an attractive target for novel antibiotic development, necessitated by emerging antibiotic resistance as well as biodefense concerns. The first committed step in the MEP pathway is the reduction and isomerization of 1-deoxy-D-xylulose-5-phosphate (DXP) to methylerythritol phosphate (MEP), catalyzed by MEP synthase. To facilitate drug development, we cloned, expressed, purified, and characterized MEP synthase from Yersinia pestis. Enzyme assays indicate apparent kinetic constants of KMDXP = 252 µM and KMNADPH = 13 µM, IC50 values for fosmidomycin and FR900098 of 710 nM and 231 nM respectively, and Ki values for fosmidomycin and FR900098 of 251 nM and 101 nM respectively. To ascertain if the Y. pestis MEP synthase was amenable to a high-throughput screening campaign, the Z-factor was determined (0.9) then the purified enzyme was screened against a pilot scale library containing rationally designed fosmidomycin analogs and natural product extracts. Several hit molecules were obtained, most notably a natural product allosteric affector of MEP synthase and a rationally designed bisubstrate derivative of FR900098 (able to associate with both the NADPH and DXP binding sites in MEP synthase). It is particularly noteworthy that allosteric regulation of MEP synthase has not been described previously. Thus, our discovery implicates an alternative site (and new chemical space) for rational drug development.
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Affiliation(s)
- Amanda Haymond
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Chinchu Johny
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Tyrone Dowdy
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Brandon Schweibenz
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Karen Villarroel
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Richard Young
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Clark J. Mantooth
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Trishal Patel
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Jessica Bases
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Geraldine San Jose
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Emily R. Jackson
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Cynthia S. Dowd
- Department of Chemistry, George Washington University, Washington DC, United States of America
| | - Robin D. Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, Virginia, United States of America
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21
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Abstract
Tuberculosis (TB) represents a major public health problem. The growing number of (extensively) multi-drug resistance cases indicates that there is an urgent need for discovery of new anti-TB entities, addressed towards new and specific targets, and continuous development of fast and efficient synthetic strategies to access them easily. Microwave-assisted chemistry is well suited for small-scale laboratory synthetic work, allowing full control of reaction conditions, such as temperature, pressure, and time. Microwave-assisted high-speed organic synthesis is especially useful in the lead optimization phase of drug discovery. To illustrate the advantages of modern microwave heating technology, we herein describe applications and approaches that have been useful for the synthesis of new drug-like anti-TB compounds.
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Affiliation(s)
- Maria De Rosa
- Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry, BMC, Uppsala University , Uppsala , Sweden
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22
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Chofor R, Risseeuw MDP, Pouyez J, Johny C, Wouters J, Dowd CS, Couch RD, Van Calenbergh S. Synthetic Fosmidomycin analogues with altered chelating moieties do not inhibit 1-deoxy-d-xylulose 5-phosphate Reductoisomerase or Plasmodium falciparum growth in vitro. Molecules 2014; 19:2571-87. [PMID: 24566322 PMCID: PMC6271069 DOI: 10.3390/molecules19022571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 11/17/2022] Open
Abstract
Fourteen new fosmidomycin analogues with altered metal chelating groups were prepared and evaluated for inhibition of E. coli Dxr, M. tuberculosis Dxr and the growth of P. falciparum K1 in human erythrocytes. None of the synthesized compounds showed activity against either enzyme or the Plasmodia. This study further underlines the importance of the hydroxamate functionality and illustrates that identifying effective alternative bidentate ligands for this target enzyme is challenging.
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Affiliation(s)
- René Chofor
- Laboratory for Medicinal Chemistry, Ghent University, Harelbekestraat 72, Ghent B-9000, Belgium.
| | - Martijn D P Risseeuw
- Laboratory for Medicinal Chemistry, Ghent University, Harelbekestraat 72, Ghent B-9000, Belgium.
| | - Jenny Pouyez
- Department of Chemistry, University of Namur, UNamur, Rue de Bruxelles 61, Namur B-5000, Belgium.
| | - Chinchu Johny
- Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110, USA.
| | - Johan Wouters
- Department of Chemistry, University of Namur, UNamur, Rue de Bruxelles 61, Namur B-5000, Belgium.
| | - Cynthia S Dowd
- Department of Chemistry, George Washington University, Washington, DC 20052, USA.
| | - Robin D Couch
- Department of Chemistry and Biochemistry, George Mason University, Manassas, VA 20110, USA.
| | - Serge Van Calenbergh
- Laboratory for Medicinal Chemistry, Ghent University, Harelbekestraat 72, Ghent B-9000, Belgium.
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23
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Midrier C, Montel S, Braun R, Haaf K, Willms L, van der Lee A, Volle JN, Pirat JL, Virieux D. Fosmidomycin analogues with N-hydroxyimidazole and N-hydroxyimidazolone as a chelating unit. RSC Adv 2014. [DOI: 10.1039/c4ra00757c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Fosmidomycin has been reported to have many biological activities as an antibacterial and antimalarial, along with being a herbicidal agent.
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Affiliation(s)
- Camille Midrier
- Institut Charles Gerhardt
- UMR5253
- AM2N
- F34296 Montpellier Cedex 5,, France
| | - Sonia Montel
- Institut Charles Gerhardt
- UMR5253
- AM2N
- F34296 Montpellier Cedex 5,, France
| | - Ralf Braun
- Bayer CropScience AG
- Chemistry Frankfurt
- 65926 Frankfurt am Main, Germany
| | - Klaus Haaf
- Bayer CropScience AG
- Chemistry Frankfurt
- 65926 Frankfurt am Main, Germany
| | - Lothar Willms
- Bayer CropScience AG
- Chemistry Frankfurt
- 65926 Frankfurt am Main, Germany
| | - Arie van der Lee
- Institut Européen des membranes
- cc047 Université de Montpellier 2
- Montpellier, France
| | - Jean-Noël Volle
- Institut Charles Gerhardt
- UMR5253
- AM2N
- F34296 Montpellier Cedex 5,, France
| | - Jean-Luc Pirat
- Institut Charles Gerhardt
- UMR5253
- AM2N
- F34296 Montpellier Cedex 5,, France
| | - David Virieux
- Institut Charles Gerhardt
- UMR5253
- AM2N
- F34296 Montpellier Cedex 5,, France
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The effect of chain length and unsaturation on Mtb Dxr inhibition and antitubercular killing activity of FR900098 analogs. Bioorg Med Chem Lett 2013; 24:649-53. [PMID: 24360562 DOI: 10.1016/j.bmcl.2013.11.067] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 11/20/2013] [Accepted: 11/25/2013] [Indexed: 11/20/2022]
Abstract
Inhibition of the nonmevalonate pathway (NMP) of isoprene biosynthesis has been examined as a source of new antibiotics with novel mechanisms of action. Dxr is the best studied of the NMP enzymes and several reports have described potent Dxr inhibitors. Many of these compounds are structurally related to natural products fosmidomycin and FR900098, each bearing retrohydroxamate and phosphonate groups. We synthesized a series of compounds with two to five methylene units separating these groups to examine what linker length was optimal and tested for inhibition against Mtb Dxr. We synthesized ethyl and pivaloyl esters of these compounds to increase lipophilicity and improve inhibition of Mtb growth. Our results show that propyl or propenyl linker chains are optimal. Propenyl analog 22 has an IC50 of 1.07 μM against Mtb Dxr. The pivaloyl ester of 22, compound 26, has an MIC of 9.4 μg/mL, representing a significant improvement in antitubercular potency in this class of compounds.
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