1
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Farr DC, Haselhorst T, Tan L, Furness J, Strong E, Grice ID, West NP, Houston TA. Reassessing the putative molecular Target(s) of potent antitubercular 2-(Alkylsulfonyl)acetamides. Eur J Med Chem 2024; 264:115983. [PMID: 38048695 DOI: 10.1016/j.ejmech.2023.115983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 11/11/2023] [Accepted: 11/19/2023] [Indexed: 12/06/2023]
Abstract
Simple alkyl-sulfonylacetamides have potent antitubercular activity and significantly decrease mycolic acid levels in mycobacteria. Although these compounds were originally designed to inhibit the ketoacyl synthase domain of fatty acid synthase, structure-activity relationships and biochemical evidence do not fully support fatty acid synthase as the target. In 2004, an enzyme family involved in the activation and transfer of fatty acids as acyl-adenylates was identified in mycobacteria, separate from the universal acetyl-CoA carrier mechanism. These fatty acyl-AMP ligases (FAAL), encoded by the FadD family play important roles in the biosynthesis of mycolic acids along with fatty acid metabolism and are hypothesised here to be the molecular target of the sulfonylacetamides. Due to structural similarities with the ligase's natural substrate, it is believed these compounds are exerting action via competitive inhibition of these highly potent molecular targets. The primary aim of this investigation was to synthesize an extended library of sulfonylacetamide derivatives, building upon existing structural activity relations to validate the molecular mechanism with the aid of molecular modelling, while also attempting to explore novel structural isosteres for further drug design and development. Sulfonylacetamide derivatives were modified based on the putative molecular target resulting in derivatives with improved activities towards Mycobacteriumtuberculosis (H37Rv). The most active novel derivatives reported were 19, 22b, 22c and 46 displaying MIC90 levels of 1.4, 16.0, 13.0 and 5.9 μg/mL, respectively.
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Affiliation(s)
- Dylan C Farr
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Thomas Haselhorst
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Lendl Tan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Juanelle Furness
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Emily Strong
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - I Darren Grice
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia; School of Pharmacy and Medical Science, Griffith University, Gold Coast, QLD, 4222, Australia
| | - Nicholas P West
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Todd A Houston
- Institute for Glycomics, Griffith University, Gold Coast, QLD, 4222, Australia.
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2
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Yang J, Zhang L, Qiao W, Luo Y. Mycobacterium tuberculosis: Pathogenesis and therapeutic targets. MedComm (Beijing) 2023; 4:e353. [PMID: 37674971 PMCID: PMC10477518 DOI: 10.1002/mco2.353] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 07/31/2023] [Accepted: 08/03/2023] [Indexed: 09/08/2023] Open
Abstract
Tuberculosis (TB) remains a significant public health concern in the 21st century, especially due to drug resistance, coinfection with diseases like immunodeficiency syndrome (AIDS) and coronavirus disease 2019, and the lengthy and costly treatment protocols. In this review, we summarize the pathogenesis of TB infection, therapeutic targets, and corresponding modulators, including first-line medications, current clinical trial drugs and molecules in preclinical assessment. Understanding the mechanisms of Mycobacterium tuberculosis (Mtb) infection and important biological targets can lead to innovative treatments. While most antitubercular agents target pathogen-related processes, host-directed therapy (HDT) modalities addressing immune defense, survival mechanisms, and immunopathology also hold promise. Mtb's adaptation to the human host involves manipulating host cellular mechanisms, and HDT aims to disrupt this manipulation to enhance treatment effectiveness. Our review provides valuable insights for future anti-TB drug development efforts.
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Affiliation(s)
- Jiaxing Yang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Laiying Zhang
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
| | - Wenliang Qiao
- Department of Thoracic Surgery, West China HospitalSichuan UniversityChengduSichuanChina
- Lung Cancer Center, West China HospitalSichuan UniversityChengduSichuanChina
| | - Youfu Luo
- Center of Infectious Diseases and State Key Laboratory of Biotherapy, West China HospitalSichuan UniversityChengduChina
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3
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D'Ambrosio HK, Keeler AM, Derbyshire ER. Examination of Secondary Metabolite Biosynthesis in Apicomplexa. Chembiochem 2023; 24:e202300263. [PMID: 37171468 DOI: 10.1002/cbic.202300263] [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: 04/01/2023] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/13/2023]
Abstract
Natural product discovery has traditionally relied on the isolation of small molecules from producing species, but genome-sequencing technology and advances in molecular biology techniques have expanded efforts to a wider array of organisms. Protists represent an underexplored kingdom for specialized metabolite searches despite bioinformatic analysis that suggests they harbor distinct biologically active small molecules. Specifically, pathogenic apicomplexan parasites, responsible for billions of global infections, have been found to possess multiple biosynthetic gene clusters, which hints at their capacity to produce polyketide metabolites. Biochemical studies have revealed unique features of apicomplexan polyketide synthases, but to date, the identity and function of the polyketides synthesized by these megaenzymes remains unknown. Herein, we discuss the potential for specialized metabolite production in protists and the possible evolution of polyketide biosynthetic gene clusters in apicomplexan parasites. We then focus on a polyketide synthase from the apicomplexan Toxoplasma gondii to discuss the unique domain architecture and properties of these proteins when compared to previously characterized systems, and further speculate on the possible functions for polyketides in these pathogenic parasites.
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Affiliation(s)
- Hannah K D'Ambrosio
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA
| | - Aaron M Keeler
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA
| | - Emily R Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, NC 27708, USA
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, NC 27710, USA
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4
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Kumar G, C A. Natural products and their analogues acting against Mycobacterium tuberculosis: A recent update. Drug Dev Res 2023; 84:779-804. [PMID: 37086027 DOI: 10.1002/ddr.22063] [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: 11/25/2022] [Revised: 02/28/2023] [Accepted: 04/01/2023] [Indexed: 04/23/2023]
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases caused by Mycobacterium tuberculosis (M.tb). It is responsible for significant causes of mortality and morbidity worldwide. M.tb possesses robust defense mechanisms against most antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. Thus, the efficacy of existing front-line drugs is diminishing, and new and recurring cases of TB arising from multidrug-resistant M.tb are increasing. TB begs the scientific community to explore novel therapeutic avenues. A precise knowledge of the compounds with their mode of action could aid in developing new anti-TB agents that can kill latent and actively multiplying M.tb. This can help in the shortening of the anti-TB regimen and can improve the outcome of treatment strategies. Natural products have contributed several antibiotics for TB treatment. The sources of anti-TB drugs/inhibitors discussed in this work are target-based identification/cell-based and phenotypic screening from natural products. Some of the recently identified natural products derived leads have reached clinical stages of TB drug development, which include rifapentine, CPZEN-45, spectinamide-1599 and 1810. We believe these anti-TB agents could emerge as superior therapeutic compounds to treat TB over known Food and Drug Administration drugs.
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Affiliation(s)
- Gautam Kumar
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Telangana, India
| | - Amrutha C
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Telangana, India
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5
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Li S, Qu Y. Structural study of medium-long chain fatty acyl-CoA ligase FadD8 from Mycobacterium tuberculosis. Biochem Biophys Res Commun 2023; 672:65-71. [PMID: 37336126 DOI: 10.1016/j.bbrc.2023.06.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 05/28/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023]
Abstract
In mycobacteria, lipids are important components of the cell wall and play a critical role for pathogenic activities. Lipids need to be activated before participating in many biological pathways. FadD proteins are members of the adenylate-forming superfamily, catalyzing activation of fatty acids. FadD8 is one of the 34 Mycobacterium tuberculosis FadD proteins, which was reported to be a putative medium-long chain fatty acyl-CoA ligase. Previous studies showed FadD8 from Mycobacterium smegmatis exhibited higher activity with oxidized cholesterol than fatty acids. However, the catalytic mechanism of the FadD8 is still exclusive. Here, we reported the crystal structure of FadD8 from Mycobacterium tuberculosis, which forms homodimer. Structural analysis revealed presence of a relatively narrow pocket compared to other FadD proteins and a novel alternative pocket, implying distinct substrate binding preference. We propose that FadD8 plays a vital role in cholesterol utilization and metabolism by catalyzing activation of cholesterol. Collectively, our findings provide novel information for the further studies of the inhibitor and drug development.
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Affiliation(s)
- Shanshan Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, People's Republic of China.
| | - Yunhui Qu
- Department of Clinical Laboratory, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, People's Republic of China.
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Kim SK, Dickinson MS, Finer-Moore J, Guan Z, Kaake RM, Echeverria I, Chen J, Pulido EH, Sali A, Krogan NJ, Rosenberg OS, Stroud RM. Structure and dynamics of the essential endogenous mycobacterial polyketide synthase Pks13. Nat Struct Mol Biol 2023; 30:296-308. [PMID: 36782050 PMCID: PMC10312659 DOI: 10.1038/s41594-022-00918-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 12/21/2022] [Indexed: 02/15/2023]
Abstract
The mycolic acid layer of the Mycobacterium tuberculosis cell wall is essential for viability and virulence, and the enzymes responsible for its synthesis are targets for antimycobacterial drug development. Polyketide synthase 13 (Pks13) is a module encoding several enzymatic and transport functions that carries out the condensation of two different long-chain fatty acids to produce mycolic acids. We determined structures by cryogenic-electron microscopy of dimeric multi-enzyme Pks13 purified from mycobacteria under normal growth conditions, captured with native substrates. Structures define the ketosynthase (KS), linker and acyl transferase (AT) domains at 1.8 Å resolution and two alternative locations of the N-terminal acyl carrier protein. These structures suggest intermediate states on the pathway for substrate delivery to the KS domain. Other domains, visible at lower resolution, are flexible relative to the KS-AT core. The chemical structures of three bound endogenous long-chain fatty acid substrates were determined by electrospray ionization mass spectrometry.
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Affiliation(s)
- Sun Kyung Kim
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Miles Sasha Dickinson
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Chemistry and Chemical Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA
| | - Janet Finer-Moore
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Ziqiang Guan
- Department of Biochemistry, Duke University Medical Center, Durham, NC, USA
| | - Robyn M Kaake
- Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA, USA
| | - Ignacia Echeverria
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA, USA
| | - Jen Chen
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Ernst H Pulido
- Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA
| | - Andrej Sali
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA, USA
| | - Nevan J Krogan
- Gladstone Institute of Data Science and Biotechnology, J. David Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA, USA
| | - Oren S Rosenberg
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
- Department of Medicine, Division of Infectious Diseases, University of California San Francisco, San Francisco, CA, USA.
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA.
- Chemistry and Chemical Biology Graduate Program, University of California San Francisco, San Francisco, CA, USA.
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7
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Kumar G, Kapoor S. Targeting mycobacterial membranes and membrane proteins: Progress and limitations. Bioorg Med Chem 2023; 81:117212. [PMID: 36804747 DOI: 10.1016/j.bmc.2023.117212] [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: 08/23/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
Among the various bacterial infections, tuberculosis continues to hold center stage. Its causative agent, Mycobacterium tuberculosis, possesses robust defense mechanisms against most front-line antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. It is now well-established that bacteria change their membrane composition to optimize their environment to survive and elude drug action. Thus targeting membrane or membrane components is a promising avenue for exploiting the chemical space focussed on developing novel membrane-centric anti-bacterial small molecules. These approaches are more effective, non-toxic, and can attenuate resistance phenotype. We present the relevance of targeting the mycobacterial membrane as a practical therapeutic approach. The review highlights the direct and indirect targeting of membrane structure and function. Direct membrane targeting agents cause perturbation in the membrane potential and can cause leakage of the cytoplasmic contents. In contrast, indirect membrane targeting agents disrupt the function of membrane-associated proteins involved in cell wall biosynthesis or energy production. We discuss the chronological chemical improvements in various scaffolds targeting specific membrane-associated protein targets, their clinical evaluation, and up-to-date account of their ''mechanisms of action, potency, selectivity'' and limitations. The sources of anti-TB drugs/inhibitors discussed in this work have emerged from target-based identification, cell-based phenotypic screening, drug repurposing, and natural products. We believe this review will inspire the exploration of uncharted chemical space for informing the development of new scaffolds that can inhibit novel mycobacterial membrane targets.
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Affiliation(s)
- Gautam Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Departemnt of Natural Products, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad 500037, India.
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan.
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8
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Mater V, Eisner S, Seidel C, Schneider D. The peripherally membrane-attached protein MbFACL6 of Mycobacterium tuberculosis activates a broad spectrum of substrates. J Mol Biol 2022; 434:167842. [PMID: 36179886 DOI: 10.1016/j.jmb.2022.167842] [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: 06/10/2022] [Revised: 09/12/2022] [Accepted: 09/20/2022] [Indexed: 11/25/2022]
Abstract
The infectious disease tuberculosis is one of the fifteen most common causes of death worldwide (according to the WHO). About every fourth person is infected with the main causative agent Mycobacterium tuberculosis (Mb). A characteristic of the pathogen is its entrance into a dormant state in which a phenotypic antibiotic resistance is achieved. To target resistant strains, novel dormancy-specific targets are very promising. Such a possible target is the Mb "fatty acid-CoA ligase 6" (MbFACL6), which activates fatty acids and thereby modulates the accumulation of triacylglycerol-containing lipid droplets that are used by Mb as an energy source during dormancy. We investigated the membrane association of MbFACL6 in E. coli and its specific activity towards different substrates after establishing a novel MbFACL6 activity assay. Despite a high homology to the mammalian family of fatty acid transport proteins, which are typically transmembrane proteins, our results indicate that MbFACL6 is a peripheral membrane-attached protein. Furthermore, MbFACL6 tolerates a broad spectrum of substrates including saturated and unsaturated fatty acids (C12-C20), some cholic acid derivatives, and even synthetic fatty acids, such as 9(E)-nitrooleicacid. Therefore, the substrate selectivity of MbFACL6 appears to be much broader than previously assumed.
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Affiliation(s)
- Veronika Mater
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany.
| | - Sabine Eisner
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany.
| | - Cornelia Seidel
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany.
| | - Dirk Schneider
- Department of Chemistry, Biochemistry, Johannes Gutenberg University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany; Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Hanns-Dieter-Hüsch-Weg 17, 55128 Mainz, Germany.
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Rudraraju RS, Daher SS, Gallardo-Macias R, Wang X, Neiditch MB, Freundlich JS. Mycobacterium tuberculosis KasA as a drug target: Structure-based inhibitor design. Front Cell Infect Microbiol 2022; 12:1008213. [PMID: 36189349 PMCID: PMC9519891 DOI: 10.3389/fcimb.2022.1008213] [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: 07/31/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Recent studies have reported the β-ketoacyl-acyl carrier protein KasA as a druggable target for Mycobacterium tuberculosis. This review summarizes the current status of major classes of KasA inhibitors with an emphasis on significant contributions from structure-based design methods leveraging X-ray crystal structures of KasA alone and in complex with inhibitors. The issues addressed within each inhibitor class are discussed while detailing the characterized interactions with KasA and structure-activity relationships. A critical analysis of these findings should lay the foundation for new KasA inhibitors to study the basic biology of M. tuberculosis and to form the basis of new antitubercular molecules of clinical significance with activity against drug-sensitive and drug-resistant infections.
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Affiliation(s)
- Reshma S. Rudraraju
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Samer S. Daher
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Ricardo Gallardo-Macias
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Xin Wang
- Department of Immunology and Infectious Diseases, Harvard University T.H. Chan School of Public Health, Boston, MA, United States
| | - Matthew B. Neiditch
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers University, Newark, NJ, United States,*Correspondence: Matthew B. Neiditch, ; Joel S. Freundlich,
| | - Joel S. Freundlich
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States,Department of Medicine, Center for Emerging and Re-emerging Pathogens, New Jersey Medical School, Rutgers University, Newark, NJ, United States,*Correspondence: Matthew B. Neiditch, ; Joel S. Freundlich,
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10
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Le NH, Constant P, Tranier S, Nahoum V, Guillet V, Maveyraud L, Daffé M, Mourey L, Verhaeghe P, Marrakchi H. Drug screening approach against mycobacterial fatty acyl-AMP ligase FAAL32 renews the interaest of the salicylanilide pharmacophore in the fight against tuberculosis. Bioorg Med Chem 2022; 71:116938. [DOI: 10.1016/j.bmc.2022.116938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 06/24/2022] [Accepted: 07/12/2022] [Indexed: 11/02/2022]
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11
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Bon C, Cabantous S, Julien S, Guillet V, Chalut C, Rima J, Brison Y, Malaga W, Sanchez-Dafun A, Gavalda S, Quémard A, Marcoux J, Waldo GS, Guilhot C, Mourey L. Solution structure of the type I polyketide synthase Pks13 from Mycobacterium tuberculosis. BMC Biol 2022; 20:147. [PMID: 35729566 PMCID: PMC9210659 DOI: 10.1186/s12915-022-01337-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 05/25/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type I polyketide synthases (PKSs) are multifunctional enzymes responsible for the biosynthesis of a group of diverse natural compounds with biotechnological and pharmaceutical interest called polyketides. The diversity of polyketides is impressive despite the limited set of catalytic domains used by PKSs for biosynthesis, leading to considerable interest in deciphering their structure-function relationships, which is challenging due to high intrinsic flexibility. Among nineteen polyketide synthases encoded by the genome of Mycobacterium tuberculosis, Pks13 is the condensase required for the final condensation step of two long acyl chains in the biosynthetic pathway of mycolic acids, essential components of the cell envelope of Corynebacterineae species. It has been validated as a promising druggable target and knowledge of its structure is essential to speed up drug discovery to fight against tuberculosis. RESULTS We report here a quasi-atomic model of Pks13 obtained using small-angle X-ray scattering of the entire protein and various molecular subspecies combined with known high-resolution structures of Pks13 domains or structural homologues. As a comparison, the low-resolution structures of two other mycobacterial polyketide synthases, Mas and PpsA from Mycobacterium bovis BCG, are also presented. This study highlights a monomeric and elongated state of the enzyme with the apo- and holo-forms being identical at the resolution probed. Catalytic domains are segregated into two parts, which correspond to the condensation reaction per se and to the release of the product, a pivot for the enzyme flexibility being at the interface. The two acyl carrier protein domains are found at opposite sides of the ketosynthase domain and display distinct characteristics in terms of flexibility. CONCLUSIONS The Pks13 model reported here provides the first structural information on the molecular mechanism of this complex enzyme and opens up new perspectives to develop inhibitors that target the interactions with its enzymatic partners or between catalytic domains within Pks13 itself.
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Affiliation(s)
- Cécile Bon
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
| | - Stéphanie Cabantous
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Los Alamos National Laboratory, Bioscience Division B-N2, Los Alamos, NM, 87545, USA.,Present address: Centre de Recherche en Cancérologie de Toulouse (CRCT), Inserm, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sylviane Julien
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Valérie Guillet
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Christian Chalut
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julie Rima
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yoann Brison
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Present address: Toulouse White Biotechnology, 31400, Toulouse, France
| | - Wladimir Malaga
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Angelique Sanchez-Dafun
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Sabine Gavalda
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.,Present address: Carbios, Biopole Clermont Limagne, 63360, Saint-Beauzire, France
| | - Annaïk Quémard
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Julien Marcoux
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Geoffrey S Waldo
- Los Alamos National Laboratory, Bioscience Division B-N2, Los Alamos, NM, 87545, USA
| | - Christophe Guilhot
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Lionel Mourey
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France.
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12
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Modak B, Girkar S, Narayan R, Kapoor S. Mycobacterial Membranes as Actionable Targets for Lipid-Centric Therapy in Tuberculosis. J Med Chem 2022; 65:3046-3065. [PMID: 35133820 DOI: 10.1021/acs.jmedchem.1c01870] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Infectious diseases remain significant health concerns worldwide, and resistance is particularly common in patients with tuberculosis caused by Mycobacterium tuberculosis. The development of anti-infectives with novel modes of action may help overcome resistance. In this regard, membrane-active agents, which modulate membrane components essential for the survival of pathogens, present attractive antimicrobial agents. Key advantages of membrane-active compounds include their ability to target slow-growing or dormant bacteria and their favorable pharmacokinetics. Here, we comprehensively review recent advances in the development of membrane-active chemotypes that target mycobacterial membranes and discuss clinically relevant membrane-active antibacterial agents that have shown promise in counteracting bacterial infections. We discuss the relationship between the membrane properties and the synthetic requirements within the chemical scaffold, as well as the limitations of current membrane-active chemotypes. This review will lay the chemical groundwork for the development of membrane-active antituberculosis agents and will foster the discovery of more effective antitubercular agents.
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Affiliation(s)
- Biswabrata Modak
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Siddhali Girkar
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Rishikesh Narayan
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Goa 403110, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.,Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan
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13
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Patil GS, Kinatukara P, Mondal S, Shambhavi S, Patel KD, Pramanik S, Dubey N, Narasimhan S, Madduri MK, Pal B, Gokhale RS, Sankaranarayanan R. A universal pocket in fatty acyl-AMP ligases ensures redirection of fatty acid pool away from coenzyme A-based activation. eLife 2021; 10:70067. [PMID: 34490847 PMCID: PMC8460268 DOI: 10.7554/elife.70067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/06/2021] [Indexed: 12/29/2022] Open
Abstract
Fatty acyl-AMP ligases (FAALs) channelize fatty acids towards biosynthesis of virulent lipids in mycobacteria and other pharmaceutically or ecologically important polyketides and lipopeptides in other microbes. They do so by bypassing the ubiquitous coenzyme A-dependent activation and rely on the acyl carrier protein-tethered 4′-phosphopantetheine (holo-ACP). The molecular basis of how FAALs strictly reject chemically identical and abundant acceptors like coenzyme A (CoA) and accept holo-ACP unlike other members of the ANL superfamily remains elusive. We show that FAALs have plugged the promiscuous canonical CoA-binding pockets and utilize highly selective alternative binding sites. These alternative pockets can distinguish adenosine 3′,5′-bisphosphate-containing CoA from holo-ACP and thus FAALs can distinguish between CoA and holo-ACP. These exclusive features helped identify the omnipresence of FAAL-like proteins and their emergence in plants, fungi, and animals with unconventional domain organizations. The universal distribution of FAALs suggests that they are parallelly evolved with FACLs for ensuring a CoA-independent activation and redirection of fatty acids towards lipidic metabolites.
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Affiliation(s)
- Gajanan S Patil
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | | | - Sudipta Mondal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Sakshi Shambhavi
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Ketan D Patel
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Surabhi Pramanik
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Noopur Dubey
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | | | - Biswajit Pal
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Rajan Sankaranarayanan
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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14
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Mapping the biosynthetic pathway of a hybrid polyketide-nonribosomal peptide in a metazoan. Nat Commun 2021; 12:4912. [PMID: 34389721 PMCID: PMC8363725 DOI: 10.1038/s41467-021-24682-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 06/30/2021] [Indexed: 11/10/2022] Open
Abstract
Polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) hybrid systems typically use complex protein-protein interactions to facilitate direct transfer of intermediates between these multimodular megaenzymes. In the canal-associated neurons (CANs) of Caenorhabditis elegans, PKS-1 and NRPS-1 produce the nemamides, the only known hybrid polyketide-nonribosomal peptides biosynthesized by animals, through a poorly understood mechanism. Here, we use genome editing and mass spectrometry to map the roles of individual PKS-1 and NRPS-1 enzymatic domains in nemamide biosynthesis. Furthermore, we show that nemamide biosynthesis requires at least five additional enzymes expressed in the CANs that are encoded by genes distributed across the worm genome. We identify the roles of these enzymes and discover a mechanism for trafficking intermediates between a PKS and an NRPS. Specifically, the enzyme PKAL-1 activates an advanced polyketide intermediate as an adenylate and directly loads it onto a carrier protein in NRPS-1. This trafficking mechanism provides a means by which a PKS-NRPS system can expand its biosynthetic potential and is likely important for the regulation of nemamide biosynthesis. The only known animal polyketide-nonribosomal peptides, the nemamides, are biosynthesized by two megasynthetases in the canal-associated neurons (CANs) of C. elegans. Here, the authors map the biosynthetic roles of individual megasynthetase domains and identify additional enzymes in the CANs required for nemamide biosynthesis.
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15
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Bose P, Harit AK, Das R, Sau S, Iyer AK, Kashaw SK. Tuberculosis: current scenario, drug targets, and future prospects. Med Chem Res 2021. [DOI: 10.1007/s00044-020-02691-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Kumar G, Narayan R, Kapoor S. Chemical Tools for Illumination of Tuberculosis Biology, Virulence Mechanisms, and Diagnosis. J Med Chem 2020; 63:15308-15332. [PMID: 33307693 DOI: 10.1021/acs.jmedchem.0c01337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tuberculosis (TB) remains one of the deadliest infectious diseases and begs the scientific community to up the ante for research and exploration of completely novel therapeutic avenues. Chemical biology-inspired design of tunable chemical tools has aided in clinical diagnosis, facilitated discovery of therapeutics, and begun to enable investigation of virulence mechanisms at the host-pathogen interface of Mycobacterium tuberculosis. This Perspective highlights chemical tools specific to mycobacterial proteins and the cell lipid envelope that have furnished rapid and selective diagnostic strategies and provided unprecedented insights into the function of the mycobacterial proteome and lipidome. We discuss chemical tools that have enabled elucidating otherwise intractable biological processes by leveraging the unique lipid and metabolite repertoire of mycobacterial species. Some of these probes represent exciting starting points with the potential to illuminate poorly understood aspects of mycobacterial pathogenesis, particularly the host membrane-pathogen interactions.
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Affiliation(s)
- Gautam Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India
| | - Rishikesh Narayan
- School of Chemical and Materials Sciences, Indian Institute of Technology Goa, Ponda 403 401, Goa, India
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India.,Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai 400 076, Maharashtra, India
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17
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The thick waxy coat of mycobacteria, a protective layer against antibiotics and the host's immune system. Biochem J 2020; 477:1983-2006. [PMID: 32470138 PMCID: PMC7261415 DOI: 10.1042/bcj20200194] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/22/2022]
Abstract
Tuberculosis, caused by the pathogenic bacterium Mycobacterium tuberculosis (Mtb), is the leading cause of death from an infectious disease, with a mortality rate of over a million people per year. This pathogen's remarkable resilience and infectivity is largely due to its unique waxy cell envelope, 40% of which comprises complex lipids. Therefore, an understanding of the structure and function of the cell wall lipids is of huge indirect clinical significance. This review provides a synopsis of the cell envelope and the major lipids contained within, including structure, biosynthesis and roles in pathogenesis.
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18
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Batt SM, Burke CE, Moorey AR, Besra GS. Antibiotics and resistance: the two-sided coin of the mycobacterial cell wall. Cell Surf 2020; 6:100044. [PMID: 32995684 PMCID: PMC7502851 DOI: 10.1016/j.tcsw.2020.100044] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/26/2020] [Accepted: 08/26/2020] [Indexed: 01/07/2023] Open
Abstract
Mycobacterium tuberculosis, the bacterium responsible for tuberculosis, is the global leading cause of mortality from an infectious agent. Part of this success relies on the unique cell wall, which consists of a thick waxy coat with tightly packed layers of complexed sugars, lipids and peptides. This coat provides a protective hydrophobic barrier to antibiotics and the host's defences, while enabling the bacterium to spread efficiently through sputum to infect and survive within the macrophages of new hosts. However, part of this success comes at a cost, with many of the current first- and second-line drugs targeting the enzymes involved in cell wall biosynthesis. The flip side of this coin is that resistance to these drugs develops either in the target enzymes or the activation pathways of the drugs, paving the way for new resistant clinical strains. This review provides a synopsis of the structure and synthesis of the cell wall and the major current drugs and targets, along with any mechanisms of resistance.
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Affiliation(s)
- Sarah M. Batt
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Christopher E. Burke
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Alice R. Moorey
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Gurdyal S. Besra
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
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19
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Shao M, McNeil M, Cook GM, Lu X. MmpL3 inhibitors as antituberculosis drugs. Eur J Med Chem 2020; 200:112390. [DOI: 10.1016/j.ejmech.2020.112390] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/24/2020] [Accepted: 04/24/2020] [Indexed: 12/14/2022]
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20
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Baran M, Grimes KD, Sibbald PA, Fu P, Boshoff HIM, Wilson DJ, Aldrich CC. Development of small-molecule inhibitors of fatty acyl-AMP and fatty acyl-CoA ligases in Mycobacterium tuberculosis. Eur J Med Chem 2020; 201:112408. [PMID: 32574901 DOI: 10.1016/j.ejmech.2020.112408] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 04/07/2020] [Accepted: 04/27/2020] [Indexed: 12/13/2022]
Abstract
Lipid metabolism in Mycobacterium tuberculosis (Mtb) relies on 34 fatty acid adenylating enzymes (FadDs) that can be grouped into two classes: fatty acyl-CoA ligases (FACLs) involved in lipid and cholesterol catabolism and long chain fatty acyl-AMP ligases (FAALs) involved in biosynthesis of the numerous essential and virulence-conferring lipids found in Mtb. The precise biochemical roles of many FACLs remain poorly characterized while the functionally non-redundant FAALs are much better understood. Here we describe the systematic investigation of 5'-O-[N-(alkanoyl)sulfamoyl]adenosine (alkanoyl adenosine monosulfamate, alkanoyl-AMS) analogs as potential multitarget FadD inhibitors for their antitubercular activity and biochemical selectivity towards representative FAAL and FACL enzymes. We identified several potent compounds including 12-azidododecanoyl-AMS 28, 11-phenoxyundecanoyl-AMS 32, and nonyloxyacetyl-AMS 36 with minimum inhibitory concentrations (MICs) against M. tuberculosis ranging from 0.098 to 3.13 μM. Compound 32 was notable for its impressive biochemical selectivity against FAAL28 (apparent Ki = 0.7 μM) versus FACL19 (Ki > 100 μM), and uniform activity against a panel of multidrug and extensively drug-resistant TB strains with MICs ranging from 3.13 to 12.5 μM in minimal (GAST) and rich (7H9) media. The SAR analysis provided valuable insights for further optimization of 32 and also identified limitations to overcome.
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Affiliation(s)
- Marzena Baran
- Department of Medicinal Chemistry, University of Minnesota, 8-101 WDH, 308 Harvard Street SE, Minneapolis, MN, 55455, United States
| | - Kimberly D Grimes
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, United States
| | - Paul A Sibbald
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, United States
| | - Peng Fu
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, United States
| | - Helena I M Boshoff
- Tuberculosis Research Section, National Institute of Allergy and Infectious Diseases, Bethesda, MD, 20892, United States
| | - Daniel J Wilson
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, United States
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, 8-101 WDH, 308 Harvard Street SE, Minneapolis, MN, 55455, United States; Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, MN, 55455, United States.
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21
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A Preclinical Candidate Targeting Mycobacterium tuberculosis KasA. Cell Chem Biol 2020; 27:560-570.e10. [PMID: 32197094 DOI: 10.1016/j.chembiol.2020.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/26/2020] [Accepted: 02/26/2020] [Indexed: 01/22/2023]
Abstract
Published Mycobacterium tuberculosis β-ketoacyl-ACP synthase KasA inhibitors lack sufficient potency and/or pharmacokinetic properties. A structure-based approach was used to optimize existing KasA inhibitor DG167. This afforded indazole JSF-3285 with a 30-fold increase in mouse plasma exposure. Biochemical, genetic, and X-ray studies confirmed JSF-3285 targets KasA. JSF-3285 offers substantial activity in an acute mouse model of infection and in the corresponding chronic infection model, with efficacious reductions in colony-forming units at doses as low as 5 mg/kg once daily orally and improvement of the efficacy of front-line drugs isoniazid or rifampicin. JSF-3285 is a promising preclinical candidate for tuberculosis.
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22
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D’Ambrosio HK, Derbyshire ER. Investigating the Role of Class I Adenylate-Forming Enzymes in Natural Product Biosynthesis. ACS Chem Biol 2020; 15:17-27. [PMID: 31815417 DOI: 10.1021/acschembio.9b00865] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adenylate-forming enzymes represent one of the most important enzyme classes in biology, responsible for the activation of carboxylate substrates for biosynthetic modifications. The byproduct of the adenylate-forming enzyme acetyl-CoA synthetase, acetyl-CoA, is incorporated into virtually every primary and secondary metabolic pathway. Modification of acetyl-CoA by an array of other adenylate-forming enzymes produces complex classes of natural products including nonribosomal peptides, polyketides, phenylpropanoids, lipopeptides, and terpenes. Adenylation domains possess a variety of unique structural and functional features that provide for such diversification in their resulting metabolites. As the number of organisms with sequenced genomes increases, more adenylate-forming enzymes are being identified, each with roles in metabolite production that have yet to be characterized. In this Review, we explore the broad role of class I adenylate-forming enzymes in the context of natural product biosynthesis and how they contribute to primary and secondary metabolism by focusing on important work conducted in the field. We highlight features of subclasses from this family that facilitate the production of structurally diverse metabolites, including those from noncanonical adenylation domains, and additionally discuss when biological roles for these compounds are known.
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Affiliation(s)
- Hannah K. D’Ambrosio
- Department of Chemistry, Duke University, 124 Science Drive, Durham, North Carolina 27708, United States
| | - Emily R. Derbyshire
- Department of Chemistry, Duke University, 124 Science Drive, Durham, North Carolina 27708, United States
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, 213 Research Drive, Durham, North Carolina 27710, United States
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23
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Abstract
Mycolic acids are the signature lipid of mycobacteria and constitute an important physical component of the cell wall, a target of mycobacterium-specific antibiotics and a mediator of Mycobacterium tuberculosis pathogenesis. Mycolic acids are synthesized in the cytoplasm and are thought to be transported to the cell wall as a trehalose ester by the MmpL3 transporter, an antibiotic target for M. tuberculosis However, the mechanism by which mycolate synthesis is coupled to transport, and the full MmpL3 transport machinery, is unknown. Here, we identify two new components of the MmpL3 transport machinery in mycobacteria. The protein encoded by MSMEG_0736/Rv0383c is essential for growth of Mycobacterium smegmatis and M. tuberculosis and is anchored to the cytoplasmic membrane, physically interacts with and colocalizes with MmpL3 in growing cells, and is required for trehalose monomycolate (TMM) transport to the cell wall. In light of these findings, we propose MSMEG_0736/Rv0383c be named "TMM transport factor A", TtfA. The protein encoded by MSMEG_5308 also interacts with the MmpL3 complex but is nonessential for growth or TMM transport. However, MSMEG_5308 accumulates with inhibition of MmpL3-mediated TMM transport and stabilizes the MmpL3/TtfA complex, indicating that it may stabilize the transport system during stress. These studies identify two new components of the mycobacterial mycolate transport machinery, an emerging antibiotic target in M. tuberculosis IMPORTANCE The cell envelope of Mycobacterium tuberculosis, the bacterium that causes the disease tuberculosis, is a complex structure composed of abundant lipids and glycolipids, including the signature lipid of these bacteria, mycolic acids. In this study, we identified two new components of the transport machinery that constructs this complex cell wall. These two accessory proteins are in a complex with the MmpL3 transporter. One of these proteins, TtfA, is required for mycolic acid transport and cell viability, whereas the other stabilizes the MmpL3 complex. These studies identify two new components of the essential cell envelope biosynthetic machinery in mycobacteria.
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24
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Alsayed SSR, Beh CC, Foster NR, Payne AD, Yu Y, Gunosewoyo H. Kinase Targets for Mycolic Acid Biosynthesis in Mycobacterium tuberculosis. Curr Mol Pharmacol 2019; 12:27-49. [PMID: 30360731 DOI: 10.2174/1874467211666181025141114] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mycolic acids (MAs) are the characteristic, integral building blocks for the mycomembrane belonging to the insidious bacterial pathogen Mycobacterium tuberculosis (M.tb). These C60-C90 long α-alkyl-β-hydroxylated fatty acids provide protection to the tubercle bacilli against the outside threats, thus allowing its survival, virulence and resistance to the current antibacterial agents. In the post-genomic era, progress has been made towards understanding the crucial enzymatic machineries involved in the biosynthesis of MAs in M.tb. However, gaps still remain in the exact role of the phosphorylation and dephosphorylation of regulatory mechanisms within these systems. To date, a total of 11 serine-threonine protein kinases (STPKs) are found in M.tb. Most enzymes implicated in the MAs synthesis were found to be phosphorylated in vitro and/or in vivo. For instance, phosphorylation of KasA, KasB, mtFabH, InhA, MabA, and FadD32 downregulated their enzymatic activity, while phosphorylation of VirS increased its enzymatic activity. These observations suggest that the kinases and phosphatases system could play a role in M.tb adaptive responses and survival mechanisms in the human host. As the mycobacterial STPKs do not share a high sequence homology to the human's, there have been some early drug discovery efforts towards developing potent and selective inhibitors. OBJECTIVE Recent updates to the kinases and phosphatases involved in the regulation of MAs biosynthesis will be presented in this mini-review, including their known small molecule inhibitors. CONCLUSION Mycobacterial kinases and phosphatases involved in the MAs regulation may serve as a useful avenue for antitubercular therapy.
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Affiliation(s)
- Shahinda S R Alsayed
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Chau C Beh
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia.,David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02142, United States
| | - Neil R Foster
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102 WA, Australia
| | - Alan D Payne
- School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Yu Yu
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
| | - Hendra Gunosewoyo
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, WA 6102, Australia
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25
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Biochemical characterization of acyl-coenzyme A synthetases involved in mycobacterial steroid side-chain catabolism and molecular design: synthesis of an anti-mycobacterial agent. 3 Biotech 2019; 9:169. [PMID: 30997306 DOI: 10.1007/s13205-019-1703-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 04/03/2019] [Indexed: 01/26/2023] Open
Abstract
The metabolism of host cholesterol by Mycobacterium tuberculosis is an important factor for both its virulence and pathogenesis. However, the rationale for this cholesterol metabolism has not been fully understood yet. In the present study, we characterized several previously undescribed acyl-CoA synthetases that are involved in the steroid side-chain degradation in Mycobacterium smegmatis, and an analogue of intermediate from steroid degradation, 5'-O-(lithocholoyl sulfamoyl) adenosine (LCA-AMS), was successfully designed and synthesized to be used as a specific anti-mycobacterial agent. The acyl-CoA synthetases exhibited strong preferences for the length of side chain. FadD19 homologs, including FadD19 (MSMEG_5914), FadD19-2 (MSMEG_2241), and FadD19-4 (MSMEG_3687), are unanimously favorable cholesterol with a C8 alkanoate side chain. FadD17 (MSMEG_5908) and FadD1 (MSMEG_4952) showed high preferences for steroids, containing a C5 alkanoate side chain. FadD8 (MSMEG_1098) exhibited specific activity toward cholestenoate with a C8 alkanoate side chain. An acylsulfamoyl analogue of lithocholate, 5'-O-(lithocholoyl sulfamoyl) adenosine (LCA-AMS), was designed and synthesized. As expected, the intermediate analogue not only specifically inhibited those steroid-activated acyl-CoA synthetases, but also selectively inhibited the growth of mycobacterial species, including M. tuberculosis, M. smegmatis, and Mycobacterium neoaurum. Overall, our research advanced our understanding of mycobacterial steroid degradation and provided new insights to develop novel mechanism-based anti-mycobacterial agents.
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26
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Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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27
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Abstract
Actinobacteria is a group of diverse bacteria. Most species in this class of bacteria are filamentous aerobes found in soil, including the genus Streptomyces perhaps best known for their fascinating capabilities of producing antibiotics. These bacteria typically have a Gram-positive cell envelope, comprised of a plasma membrane and a thick peptidoglycan layer. However, there is a notable exception of the Corynebacteriales order, which has evolved a unique type of outer membrane likely as a consequence of convergent evolution. In this chapter, we will focus on the unique cell envelope of this order. This cell envelope features the peptidoglycan layer that is covalently modified by an additional layer of arabinogalactan . Furthermore, the arabinogalactan layer provides the platform for the covalent attachment of mycolic acids , some of the longest natural fatty acids that can contain ~100 carbon atoms per molecule. Mycolic acids are thought to be the main component of the outer membrane, which is composed of many additional lipids including trehalose dimycolate, also known as the cord factor. Importantly, a subset of bacteria in the Corynebacteriales order are pathogens of human and domestic animals, including Mycobacterium tuberculosis. The surface coat of these pathogens are the first point of contact with the host immune system, and we now know a number of host receptors specific to molecular patterns exposed on the pathogen's surface, highlighting the importance of understanding how the cell envelope of Actinobacteria is structured and constructed. This chapter describes the main structural and biosynthetic features of major components found in the actinobacterial cell envelopes and highlights the key differences between them.
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Affiliation(s)
- Kathryn C Rahlwes
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA
| | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 North Pleasant Street, Amherst, MA, 01003, USA.
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28
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Chikhale RV, Barmade MA, Murumkar PR, Yadav MR. Overview of the Development of DprE1 Inhibitors for Combating the Menace of Tuberculosis. J Med Chem 2018; 61:8563-8593. [PMID: 29851474 DOI: 10.1021/acs.jmedchem.8b00281] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1), a vital enzyme for cell wall synthesis, plays a crucial role in the formation of lipoarabinomannan and arabinogalactan. It was first reported as a druggable target on the basis of inhibitors discovered in high throughput screening of a drug library. Since then, inhibitors with different types of chemical scaffolds have been reported for their activity against this enzyme. Formation of a covalent or noncovalent bond by the interacting ligand with the enzyme causes loss of its catalytic activity which ultimately leads to the death of the mycobacterium. This Perspective describes various DprE1 inhibitors as anti-TB agents reported to date.
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Affiliation(s)
- Rupesh V Chikhale
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India.,School of Health Sciences, Division of Pharmacy and Optometry , University of Manchester , Manchester M13 9PL , U.K
| | - Mahesh A Barmade
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
| | - Prashant R Murumkar
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
| | - Mange Ram Yadav
- Faculty of Pharmacy, Kalabhavan Campus , The Maharaja Sayajirao University of Baroda , Vadodara 390 001 , India
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29
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Yang J, Liu Y, Liu Z, Meng C, Lin D. Backbone and side-chain resonance assignments for the tmRNA-binding protein, SmpB, from Mycobacterium tuberculosis. BIOMOLECULAR NMR ASSIGNMENTS 2017; 11:175-179. [PMID: 28258549 DOI: 10.1007/s12104-017-9742-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/24/2017] [Indexed: 06/06/2023]
Abstract
Small protein B (SmpB) is an essential molecule in trans-translation which is a universal biological pathway for protein synthesis in bacteria. Trans-translation can release stalled ribosomes from defective mRNAs and target tag-protein fragments for degradation, and then restart protein synthesis. The SmpB-tmRNA complex coordinating with other components of the trans-translation system, plays vital roles in Mycobacterium tuberculosis under both stress conditions and non-replicating conditions. Thus, elucidation of molecular details and dynamic properties of the SmpB-tmRNA interaction is a crucial step towards effectively blocking trans-translation process to shorten the duration of tuberculosis treatment. Here, we report resonance assignments for 1H, 13C and 15N of M. tuberculosis SmpB (MtSmpB, spanning residues 4-133) protein determined by a suite of 2D/3D heteronuclear NMR experiments along with predicted the secondary structure.
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Affiliation(s)
- Juanjuan Yang
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Yindi Liu
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Zhao Liu
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Chun Meng
- Institute of Pharmaceutical Biotechnology and Engineering, College of Biological Science and Biotechnology, Fuzhou University, Fuzhou, Fujian, 350108, China
| | - Donghai Lin
- MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Key Laboratory for Chemical Biology of Fujian Province, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
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30
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Lone MY, Manhas A, Athar M, Jha PC. Identification of InhA inhibitors: A combination of virtual screening, molecular dynamics simulations and quantum chemical studies. J Biomol Struct Dyn 2017; 36:2951-2965. [DOI: 10.1080/07391102.2017.1372313] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Mohsin Y. Lone
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar 382030, Gujarat, India
| | - Anu Manhas
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar 382030, Gujarat, India
| | - Mohd. Athar
- School of Chemical Sciences, Central University of Gujarat, Gandhinagar 382030, Gujarat, India
| | - Prakash C. Jha
- Centre for Applied Chemistry, Central University of Gujarat, Gandhinagar 382030, Gujarat, India
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31
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Lone MY, Athar M, Gupta VK, Jha PC. Identification of Mycobacterium tuberculosis enoyl-acyl carrier protein reductase inhibitors: A combined in-silico and in-vitro analysis. J Mol Graph Model 2017; 76:172-180. [DOI: 10.1016/j.jmgm.2017.07.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 01/20/2023]
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32
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Anti-tubercular drug discovery: in silico implications and challenges. Eur J Pharm Sci 2017; 104:1-15. [PMID: 28341614 DOI: 10.1016/j.ejps.2017.03.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/08/2017] [Accepted: 03/19/2017] [Indexed: 12/18/2022]
Abstract
Tuberculosis (TB) has been reported as a major public health concern, especially in the developing countries. WHO report on tuberculosis 2016 shows a high mortality rate caused by TB leading to 1.8 million deaths worldwide (including deaths due to TB in HIV positive individuals), which is one of the top 10 causes of mortality in 2015. However, the main therapy used for the treatment of TB is still the Direct Observed Therapy Short-course (DOTS) that consists of four main first-line drugs. Due to the prolonged and unorganized use of these drugs, Mycobacterium tuberculosis (Mtb) has developed drug-resistance against them. To overcome this drug-resistance, efforts are continuously being made to develop new therapeutics. New drug-targets of Mtb are pursued by the researchers to develop their inhibitors. For this, new methodologies that comprise of the computational drug designing techniques are vigorously applied. A major limitation that is found with these techniques is the inability of the newly identified target-based inhibitors to inhibit the whole cell bacteria. A foremost factor for this limitation is the inability of these inhibitors to penetrate the bacterial cell wall. In this regard, various strategies to overcome this limitation have been discussed in detail in this review, along with new targets and new methodologies. A bunch of in silico tools available for the prediction of physicochemical properties that need to be explored to deal with the permeability issue of the Mtb inhibitors has also been discussed.
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33
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Le NH, Molle V, Eynard N, Miras M, Stella A, Bardou F, Galandrin S, Guillet V, André-Leroux G, Bellinzoni M, Alzari P, Mourey L, Burlet-Schiltz O, Daffé M, Marrakchi H. Ser/Thr Phosphorylation Regulates the Fatty Acyl-AMP Ligase Activity of FadD32, an Essential Enzyme in Mycolic Acid Biosynthesis. J Biol Chem 2016; 291:22793-22805. [PMID: 27590338 DOI: 10.1074/jbc.m116.748053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 08/31/2016] [Indexed: 12/21/2022] Open
Abstract
Mycolic acids are essential components of the mycobacterial cell envelope, and their biosynthetic pathway is a well known source of antituberculous drug targets. Among the promising new targets in the pathway, FadD32 is an essential enzyme required for the activation of the long meromycolic chain of mycolic acids and is essential for mycobacterial growth. Following the in-depth biochemical, biophysical, and structural characterization of FadD32, we investigated its putative regulation via post-translational modifications. Comparison of the fatty acyl-AMP ligase activity between phosphorylated and dephosphorylated FadD32 isoforms showed that the native protein is phosphorylated by serine/threonine protein kinases and that this phosphorylation induced a significant loss of activity. Mass spectrometry analysis of the native protein confirmed the post-translational modifications and identified Thr-552 as the phosphosite. Phosphoablative and phosphomimetic FadD32 mutant proteins confirmed both the position and the importance of the modification and its correlation with the negative regulation of FadD32 activity. Investigation of the mycolic acid condensation reaction catalyzed by Pks13, involving FadD32 as a partner, showed that FadD32 phosphorylation also impacts the condensation activity. Altogether, our results bring to light FadD32 phosphorylation by serine/threonine protein kinases and its correlation with the enzyme-negative regulation, thus shedding a new horizon on the mycolic acid biosynthesis modulation and possible inhibition strategies for this promising drug target.
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Affiliation(s)
- Nguyen-Hung Le
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Virginie Molle
- the Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, Université de Montpellier, CNRS UMR 5235, Place Eugène Bataillon, 34095 Montpellier Cedex 05, and
| | - Nathalie Eynard
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Mathieu Miras
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Alexandre Stella
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Fabienne Bardou
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Ségolène Galandrin
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Valérie Guillet
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Gwenaëlle André-Leroux
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Marco Bellinzoni
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Pedro Alzari
- the Institut Pasteur, Unité de Microbiologie Structurale, 25 Rue du Docteur Roux, 75724 Paris Cedex 15, France
| | - Lionel Mourey
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Odile Burlet-Schiltz
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS
| | - Mamadou Daffé
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS,
| | - Hedia Marrakchi
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS,
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34
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Quémard A. New Insights into the Mycolate-Containing Compound Biosynthesis and Transport in Mycobacteria. Trends Microbiol 2016; 24:725-738. [DOI: 10.1016/j.tim.2016.04.009] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/14/2016] [Accepted: 04/29/2016] [Indexed: 12/15/2022]
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Kuhn ML, Alexander E, Minasov G, Page HJ, Warwrzak Z, Shuvalova L, Flores KJ, Wilson DJ, Shi C, Aldrich CC, Anderson WF. Structure of the Essential Mtb FadD32 Enzyme: A Promising Drug Target for Treating Tuberculosis. ACS Infect Dis 2016; 2:579-591. [PMID: 27547819 DOI: 10.1021/acsinfecdis.6b00082] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Mycolic acids are indispensible lipids of Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), and contribute to the distinctive architecture and impermeability of the mycobacterial cell envelope. FadD32 plays a pivotal role in mycolic acid biosynthesis by functionally linking fatty acid synthase (FAS) and polyketide synthase (PKS) biosynthetic pathways. FadD32, a fatty acyl-AMP ligase (FAAL), represents one of the best genetically and chemically validated new TB drug targets. We have determined the three-dimensional crystal structure of Mtb FadD32 in complex with a ligand specifically designed to stabilize the catalytically active adenylate-conformation, which provides a foundation for structure-based drug design efforts against this essential protein. The structure also captures the unique interactions of a FAAL-specific insertion sequence and provides insight into the specificity and mechanism of fatty acid transfer.
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Affiliation(s)
- Misty L. Kuhn
- Center for Structural
Genomics of Infectious Diseases, Department of Biochemistry and Molecular
Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, United States
| | | | - George Minasov
- Center for Structural
Genomics of Infectious Diseases, Department of Biochemistry and Molecular
Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Holland J. Page
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132, United States
| | - Zdzislaw Warwrzak
- LS-CAT,
Synchrotron Research Center, Northwestern University, Argonne, Illinois 60439, United States
| | - Ludmilla Shuvalova
- Center for Structural
Genomics of Infectious Diseases, Department of Biochemistry and Molecular
Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | - Kristin J. Flores
- Center for Structural
Genomics of Infectious Diseases, Department of Biochemistry and Molecular
Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
| | | | | | | | - Wayne F. Anderson
- Center for Structural
Genomics of Infectious Diseases, Department of Biochemistry and Molecular
Genetics, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611, United States
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36
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Guillet V, Galandrin S, Maveyraud L, Ladevèze S, Mariaule V, Bon C, Eynard N, Daffé M, Marrakchi H, Mourey L. Insight into Structure-Function Relationships and Inhibition of the Fatty Acyl-AMP Ligase (FadD32) Orthologs from Mycobacteria. J Biol Chem 2016; 291:7973-89. [PMID: 26900152 DOI: 10.1074/jbc.m115.712612] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Indexed: 12/14/2022] Open
Abstract
Mycolic acids are essential components of the mycobacterial cell envelope, and their biosynthetic pathway is one of the targets of first-line antituberculous drugs. This pathway contains a number of potential targets, including some that have been identified only recently and have yet to be explored. One such target, FadD32, is required for activation of the long meromycolic chain and is essential for mycobacterial growth. We report here an in-depth biochemical, biophysical, and structural characterization of four FadD32 orthologs, including the very homologous enzymes fromMycobacterium tuberculosisandMycobacterium marinum Determination of the structures of two complexes with alkyl adenylate inhibitors has provided direct information, with unprecedented detail, about the active site of the enzyme and the associated hydrophobic tunnel, shedding new light on structure-function relationships and inhibition mechanisms by alkyl adenylates and diarylated coumarins. This work should pave the way for the rational design of inhibitors of FadD32, a highly promising drug target.
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Affiliation(s)
- Valérie Guillet
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Ségolène Galandrin
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Laurent Maveyraud
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Simon Ladevèze
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Vincent Mariaule
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Cécile Bon
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Nathalie Eynard
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Mamadou Daffé
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Hedia Marrakchi
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
| | - Lionel Mourey
- From the Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, 31077 Toulouse, France
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37
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Li W, Gu S, Fleming J, Bi L. Crystal structure of FadD32, an enzyme essential for mycolic acid biosynthesis in mycobacteria. Sci Rep 2015; 5:15493. [PMID: 26628098 PMCID: PMC4667280 DOI: 10.1038/srep15493] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/04/2015] [Indexed: 02/01/2023] Open
Abstract
Fatty acid degradation protein D32 (FadD32), an enzyme required for mycolic acid biosynthesis and essential for mycobacterial growth, has recently been identified as a valid and promising target for anti-tuberculosis drug development. Here we report the crystal structures of Mycobacterium smegmatis FadD32 in the apo and ATP-bound states at 2.4 Å and 2.25 Å resolution, respectively. FadD32 consists of two globular domains connected by a flexible linker. ATP binds in a cleft at the interface between the N- and C-terminal domains and its binding induces significant local conformational changes in FadD32. The binding sites of meromycolic acid and phosphopantetheine are identified by structural comparison with other members of the adenylating enzyme superfamily. These results will improve our understanding of the catalytic mechanism of FadD32 and help in the design of inhibitors of this essential enzyme.
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Affiliation(s)
- Wenjuan Li
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Shoujin Gu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Joy Fleming
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Lijun Bi
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
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38
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Thanna S, Sucheck SJ. Targeting the trehalose utilization pathways of Mycobacterium tuberculosis. MEDCHEMCOMM 2015; 7:69-85. [PMID: 26941930 PMCID: PMC4770839 DOI: 10.1039/c5md00376h] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Tuberculosis (TB) is an epidemic disease and the growing burden of multidrug-resistant (MDR) TB world wide underlines the need to discover new drugs to treat the disease. Mycobacterium tuberculosis (Mtb) is the etiological agent of most cases of TB. Mtb is difficult to treat, in part, due to the presence of a sturdy hydrophobic barrier that prevents penetration of drugs through the cell wall. Mtb can also survive in a non-replicative state for long periods of time avoiding the action of common antibiotics. Trehalose is an essential metabolite in mycobacteria since it plays key roles in cell wall synthesis, transport of cell wall glycolipids, and energy storage. It is also known for its stress protective roles such as: protection from desiccation, freezing, starvation and osmotic stress in bacteria. In this review we discuss the drug discovery efforts against enzymes involved in the trehalose utilization pathways (TUPs) and their likelihood of becoming drug targets.
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Affiliation(s)
- Sandeep Thanna
- Department of Chemistry and Biochemistry, The University of Toledo, 2801 W. Bancroft Street, MS602, Toledo, OH, USA 43606
| | - Steven J. Sucheck
- Department of Chemistry and Biochemistry, The University of Toledo, 2801 W. Bancroft Street, MS602, Toledo, OH, USA 43606
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39
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Miyazawa T, Takahashi S, Kawata A, Panthee S, Hayashi T, Shimizu T, Nogawa T, Osada H. Identification of Middle Chain Fatty Acyl-CoA Ligase Responsible for the Biosynthesis of 2-Alkylmalonyl-CoAs for Polyketide Extender Unit. J Biol Chem 2015; 290:26994-27011. [PMID: 26378232 DOI: 10.1074/jbc.m115.677195] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Indexed: 11/06/2022] Open
Abstract
Understanding the biosynthetic mechanism of the atypical polyketide extender unit is important for the development of bioactive natural products. Reveromycin (RM) derivatives produced by Streptomyces sp. SN-593 possess several aliphatic extender units. Here, we studied the molecular basis of 2-alkylmalonyl-CoA formation by analyzing the revR and revS genes, which form a transcriptional unit with the revT gene, a crotonyl-CoA carboxylase/reductase homolog. We mainly focused on the uncharacterized adenylate-forming enzyme (RevS). revS gene disruption resulted in the reduction of all RM derivatives, whereas reintroduction of the gene restored the yield of RMs. Although RevS was classified in the fatty acyl-AMP ligase clade based on phylogenetic analysis, biochemical characterization revealed that the enzyme catalyzed the middle chain fatty acyl-CoA ligase (FACL) but not the fatty acyl-AMP ligase activity, suggesting the molecular evolution for acyl-CoA biosynthesis. Moreover, we examined the in vitro conversion of fatty acid into 2-alkylmalonyl-CoA using purified RevS and RevT. The coupling reaction showed efficient conversion of hexenoic acid into butylmalonyl-CoA. RevS efficiently catalyzed C8-C10 middle chain FACL activity; therefore, we speculated that the acyl-CoA precursor was truncated via β-oxidation and converted into (E)-2-enoyl-CoA, a RevT substrate. To determine whether the β-oxidation process is involved between the RevS and RevT reaction, we performed the feeding experiment using [1,2,3,4-(13)C]octanoic acid. (13)C NMR analysis clearly demonstrated incorporation of the [3,4-(13)C]octanoic acid moiety into the structure of RM-A. Our results provide insight into the role of uncharacterized RevS homologs that may catalyze middle chain FACL to produce a unique polyketide extender unit.
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Affiliation(s)
- Takeshi Miyazawa
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and; the Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Shunji Takahashi
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and
| | - Akihiro Kawata
- the Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan
| | - Suresh Panthee
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and
| | - Teruo Hayashi
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and
| | - Takeshi Shimizu
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and
| | - Toshihiko Nogawa
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and
| | - Hiroyuki Osada
- RIKEN Center for Sustainable Resource Science, Chemical Biology Research Group, Saitama 351-0198 and; the Graduate School of Science and Engineering, Saitama University, Saitama 338-8570, Japan.
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40
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Biosynthesis of cell envelope-associated phenolic glycolipids in Mycobacterium marinum. J Bacteriol 2015; 197:1040-50. [PMID: 25561717 DOI: 10.1128/jb.02546-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phenolic glycolipids (PGLs) are polyketide synthase-derived glycolipids unique to pathogenic mycobacteria. PGLs are found in several clinically relevant species, including various Mycobacterium tuberculosis strains, Mycobacterium leprae, and several nontuberculous mycobacterial pathogens, such as M. marinum. Multiple lines of investigation implicate PGLs in virulence, thus underscoring the relevance of a deep understanding of PGL biosynthesis. We report mutational and biochemical studies that interrogate the mechanism by which PGL biosynthetic intermediates (p-hydroxyphenylalkanoates) synthesized by the iterative polyketide synthase Pks15/1 are transferred to the noniterative polyketide synthase PpsA for acyl chain extension in M. marinum. Our findings support a model in which the transfer of the intermediates is dependent on a p-hydroxyphenylalkanoyl-AMP ligase (FadD29) acting as an intermediary between the iterative and the noniterative synthase systems. Our results also establish the p-hydroxyphenylalkanoate extension ability of PpsA, the first-acting enzyme of a multisubunit noniterative polyketide synthase system. Notably, this noniterative system is also loaded with fatty acids by a specific fatty acyl-AMP ligase (FadD26) for biosynthesis of phthiocerol dimycocerosates (PDIMs), which are nonglycosylated lipids structurally related to PGLs. To our knowledge, the partially overlapping PGL and PDIM biosynthetic pathways provide the first example of two distinct, pathway-dedicated acyl-AMP ligases loading the same type I polyketide synthase system with two alternate starter units to produce two structurally different families of metabolites. The studies reported here advance our understanding of the biosynthesis of an important group of mycobacterial glycolipids.
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The Polyketide Synthase Pks13 Catalyzes a Novel Mechanism of Lipid Transfer in Mycobacteria. ACTA ACUST UNITED AC 2014; 21:1660-9. [DOI: 10.1016/j.chembiol.2014.10.011] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 11/19/2022]
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Abstract
ABSTRACT
Mycolic acids are major and specific long-chain fatty acids that represent essential components of the
Mycobacterium tuberculosis
cell envelope. They play a crucial role in the cell wall architecture and impermeability, hence the natural resistance of mycobacteria to most antibiotics, and represent key factors in mycobacterial virulence. Biosynthesis of mycolic acid precursors requires two types of fatty acid synthases (FASs), the eukaryotic-like multifunctional enzyme FAS I and the acyl carrier protein (ACP)–dependent FAS II systems, which consists of a series of discrete mono-functional proteins, each catalyzing one reaction in the pathway. Unlike FAS II synthases of other bacteria, the mycobacterial FAS II is incapable of
de novo
fatty acid synthesis from acetyl-coenzyme A, but instead elongates medium-chain-length fatty acids previously synthesized by FAS I, leading to meromycolic acids. In addition, mycolic acid subspecies with defined biological properties can be distinguished according to the chemical modifications decorating the meromycolate. Nearly all the genetic components involved in both elongation and functionalization of the meromycolic acid have been identified and are generally clustered in distinct transcriptional units. A large body of information has been generated on the enzymology of the mycolic acid biosynthetic pathway and on their genetic and biochemical/structural characterization as targets of several antitubercular drugs. This chapter is a comprehensive overview of mycolic acid structure, function, and biosynthesis. Special emphasis is given to recent work addressing the regulation of mycolic acid biosynthesis, adding new insights to our understanding of how pathogenic mycobacteria adapt their cell wall composition in response to environmental changes.
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Abstract
Mycobacteria are surrounded by a complex multilayered envelope and elongate at the poles. The principles that organize the coordinated addition of chemically diverse cell wall layers during polar extension remain unclear. We show that enzymes mediating the terminal cytosolic steps of peptidoglycan, arabinogalactan, and mycolic acid synthesis colocalize at sites of cell growth or division. The tropomyosin-like protein, DivIVA, is targeted to the negative curvature of the pole, is enriched at the growing end, and determines cell shape from this site. In contrast, cell wall synthetic complexes are concentrated at a distinct subpolar location. When viewed at subdiffraction resolution, new peptidoglycan is deposited at this subpolar site, and inert cell wall covers the DivIVA-marked tip. The differentiation between polar tip and cell wall synthetic complexes is also apparent at the biochemical level. Enzymes that generate mycolate precursors interact with DivIVA, but the final condensation of mycolic acids occurs in a distinct protein complex at the site of nascent cell wall addition. We propose an ultrastructural model of mycobacterial polar growth where new cell wall is added in an annular zone below the cell tip. This model may be broadly applicable to other bacterial and fungal organisms that grow via polar extension.
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Abstract
Mycobacterium tuberculosis, which is the aetiological agent of tuberculosis, owes much of its success as a pathogen to its unique cell wall and unusual mechanism of growth, which facilitate its adaptation to the human host and could have a role in clinical latency. Asymmetric growth and division increase population heterogeneity, which may promote antibiotic tolerance and the fitness of single cells. In this Review, we describe the unusual mechanisms of mycobacterial growth, cell wall biogenesis and division, and discuss how these processes might affect the survival of M. tuberculosis in vivo and contribute to the persistence of infection.
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Abstract
Efforts from the TB Structural Genomics Consortium together with those of tuberculosis structural biologists worldwide have led to the determination of about 350 structures, making up nearly a tenth of the pathogen's proteome. Given that knowledge of protein structures is essential to obtaining a high-resolution understanding of the underlying biology, it is desirable to have a structural view of the entire proteome. Indeed, structure prediction methods have advanced sufficiently to allow structural models of many more proteins to be built based on homology modeling and fold recognition strategies. By means of these approaches, structural models for about 2,877 proteins, making up nearly 70% of the Mycobacterium tuberculosis proteome, are available. Knowledge from bioinformatics has made significant inroads into an improved annotation of the M. tuberculosis genome and in the prediction of key protein players that interact in vital pathways, some of which are unique to the organism. Functional inferences have been made for a large number of proteins based on fold-function associations. More importantly, ligand-binding pockets of the proteins are identified and scanned against a large database, leading to binding site-based ligand associations and hence structure-based function annotation. Near proteome-wide structural models provide a global perspective of the fold distribution in the genome. New insights about the folds that predominate in the genome, as well as the fold combinations that make up multidomain proteins, are also obtained. This chapter describes the structural proteome, functional inferences drawn from it, and its applications in drug discovery.
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Quadri LEN. Biosynthesis of mycobacterial lipids by polyketide synthases and beyond. Crit Rev Biochem Mol Biol 2014; 49:179-211. [DOI: 10.3109/10409238.2014.896859] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Jackson M, McNeil MR, Brennan PJ. Progress in targeting cell envelope biogenesis in Mycobacterium tuberculosis. Future Microbiol 2014; 8:855-75. [PMID: 23841633 DOI: 10.2217/fmb.13.52] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Most of the newly discovered compounds showing promise for the treatment of TB, notably multidrug-resistant TB, inhibit aspects of Mycobacterium tuberculosis cell envelope metabolism. This review reflects on the evolution of the knowledge that many of the front-line and emerging products inhibit aspects of cell envelope metabolism and in the process are bactericidal not only against actively replicating M. tuberculosis, but contrary to earlier impressions, are effective against latent forms of the disease. While mycolic acid and arabinogalactan synthesis are still primary targets of existing and new drugs, peptidoglycan synthesis, transport mechanisms and the synthesis of the decaprenyl-phosphate carrier lipid all show considerable promise as targets for new products, older drugs and new combinations. The advantages of whole cell- versus target-based screening in the perpetual search for new targets and products to counter multidrug-resistant TB are discussed.
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Affiliation(s)
- Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology & Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA.
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48
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Mycolic acids: structures, biosynthesis, and beyond. ACTA ACUST UNITED AC 2013; 21:67-85. [PMID: 24374164 DOI: 10.1016/j.chembiol.2013.11.011] [Citation(s) in RCA: 355] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 11/04/2013] [Accepted: 11/27/2013] [Indexed: 11/24/2022]
Abstract
Mycolic acids are major and specific lipid components of the mycobacterial cell envelope and are essential for the survival of members of the genus Mycobacterium that contains the causative agents of both tuberculosis and leprosy. In the alarming context of the emergence of multidrug-resistant, extremely drug-resistant, and totally drug-resistant tuberculosis, understanding the biosynthesis of these critical determinants of the mycobacterial physiology is an important goal to achieve, because it may open an avenue for the development of novel antimycobacterial agents. This review focuses on the chemistry, structures, and known inhibitors of mycolic acids and describes progress in deciphering the mycolic acid biosynthetic pathway. The functional and key biological roles of these molecules are also discussed, providing a historical perspective in this dynamic area.
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Kawate T, Iwase N, Shimizu M, Stanley SA, Wellington S, Kazyanskaya E, Hung DT. Synthesis and structure-activity relationships of phenyl-substituted coumarins with anti-tubercular activity that target FadD32. Bioorg Med Chem Lett 2013; 23:6052-9. [PMID: 24103299 DOI: 10.1016/j.bmcl.2013.09.035] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/07/2013] [Accepted: 09/11/2013] [Indexed: 11/16/2022]
Abstract
In an effort to develop new and potent agents for therapy against tuberculosis, a high-throughput screen was performed against Mycobacterium tuberculosis strain H37Rv. Two 6-aryl-5,7-dimethyl-4-phenylcoumarin compounds 1a and 1b were found with modest activity. A series of coumarin derivatives were synthesized to improve potency and to investigate the structure-activity relationship of the series. Among them, compounds 1o and 2d showed improved activity with IC90 of 2 μM and 0.5 μM, respectively. Further optimization provided compound 3b with better physiochemical properties with IC90 0.4 μM which had activity in a mouse model of infection. The role of the conformation of the 4- and 6-aryl substituents is also described.
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Affiliation(s)
- Tomohiko Kawate
- The Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Department of Molecular Biology, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA; Center for Computational and Integrative, Massachusetts General Hospital, 185 Cambridge Street, Boston, MA 02114, USA; Department of Microbiology and Immunobiology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA
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Diarylcoumarins inhibit mycolic acid biosynthesis and kill Mycobacterium tuberculosis by targeting FadD32. Proc Natl Acad Sci U S A 2013; 110:11565-70. [PMID: 23798446 DOI: 10.1073/pnas.1302114110] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Infection with the bacterial pathogen Mycobacterium tuberculosis imposes an enormous burden on global public health. New antibiotics are urgently needed to combat the global tuberculosis pandemic; however, the development of new small molecules is hindered by a lack of validated drug targets. Here, we describe the identification of a 4,6-diaryl-5,7-dimethyl coumarin series that kills M. tuberculosis by inhibiting fatty acid degradation protein D32 (FadD32), an enzyme that is required for biosynthesis of cell-wall mycolic acids. These substituted coumarin inhibitors directly inhibit the acyl-acyl carrier protein synthetase activity of FadD32. They effectively block bacterial replication both in vitro and in animal models of tuberculosis, validating FadD32 as a target for antibiotic development that works in the same pathway as the established antibiotic isoniazid. Targeting new steps in well-validated biosynthetic pathways in antitubercular therapy is a powerful strategy that removes much of the usual uncertainty surrounding new targets and in vivo clinical efficacy, while circumventing existing resistance to established targets.
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