1
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Arejan NH, Czapski DR, Buonomo JA, Boutte CC. MmpL3, Wag31, and PlrA are involved in coordinating polar growth with peptidoglycan metabolism and nutrient availability. J Bacteriol 2024:e0020424. [PMID: 39320104 DOI: 10.1128/jb.00204-24] [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: 05/08/2024] [Accepted: 07/23/2024] [Indexed: 09/26/2024] Open
Abstract
Cell growth in mycobacteria involves cell wall expansion that is restricted to the cell poles. The DivIVA homolog Wag31 is required for this process, but the molecular mechanism and protein partners of Wag31 have not been described. In this study of Mycobacterium smegmatis, we identify a connection between wag31 and trehalose monomycolate (TMM) transporter mmpl3 in a suppressor screen and show that Wag31 and polar regulator PlrA are required for MmpL3's polar localization. In addition, the localization of PlrA and MmpL3 is responsive to nutrient and energy deprivation and inhibition of peptidoglycan metabolism. We show that inhibition of MmpL3 causes delocalized cell wall metabolism but does not delocalize MmpL3 itself. We found that cells with an MmpL3 C-terminal truncation, which is defective for localization, have only minor defects in polar growth but are impaired in their ability to downregulate cell wall metabolism under stress. Our work suggests that, in addition to its established function in TMM transport, MmpL3 has a second function in regulating global cell wall metabolism in response to stress. Our data are consistent with a model in which the presence of TMMs in the periplasm stimulates polar elongation and in which the connection between Wag31, PlrA, and the C-terminus of MmpL3 is involved in detecting and responding to stress in order to coordinate the synthesis of the different layers of the mycobacterial cell wall in changing conditions. IMPORTANCE This study is performed in Mycobacterium smegmatis, which is used as a model to understand the basic physiology of pathogenic mycobacteria such as Mycobacterium tuberculosis. In this work, we examine the function and regulation of three proteins involved in regulating cell wall elongation in mycobacterial cells, which occurs at the cell tips or poles. We find that Wag31, a regulator of polar elongation, works partly through the regulation of MmpL3, a transporter of cell wall constituents and an important drug target. Our work suggests that, beyond its transport function, MmpL3 has another function in controlling cell wall synthesis broadly in response to stress.
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Affiliation(s)
| | - Desiree R Czapski
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | - Joseph A Buonomo
- Department of Chemistry and Biochemistry, University of Texas, Arlington, Texas, USA
| | - Cara C Boutte
- Department of Biology, University of Texas, Arlington, Texas, USA
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2
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Babii S, Li W, Yang L, Grzegorzewicz AE, Jackson M, Gumbart JC, Zgurskaya HI. Allosteric coupling of substrate binding and proton translocation in MmpL3 transporter from Mycobacterium tuberculosis. mBio 2024:e0218324. [PMID: 39212407 DOI: 10.1128/mbio.02183-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2024] [Accepted: 08/01/2024] [Indexed: 09/04/2024] Open
Abstract
Infections caused by Mycobacterium spp. are very challenging to treat, and multidrug-resistant strains rapidly spread in human populations. Major contributing factors include the unique physiological features of these bacteria, drug efflux, and the low permeability barrier of their outer membrane. Here, we focus on MmpL3 from Mycobacterium tuberculosis, an essential inner membrane transporter of the resistance-nodulation-division superfamily required for the translocation of mycolic acids in the form of trehalose monomycolates (TMM) from the cytoplasm or plasma membrane to the periplasm or outer membrane. The MmpL3-dependent transport of TMM is essential for the growth of M. tuberculosis in vitro, inside macrophages, and in M. tuberculosis-infected mice. MmpL3 is also a validated target for several recently identified anti-mycobacterial agents. In this study, we reconstituted the lipid transport activity of the purified MmpL3 using a two-lipid vesicle system and established the ability of MmpL3 to actively extract phospholipids from the outer leaflet of a lipid bilayer. In contrast, we found that MmpL3 lacks the ability to translocate the same phospholipid substrate across the plasma membrane indicating that it is not an energy-dependent flippase. The lipid extraction activity was modulated by substitutions in critical charged and polar residues of the periplasmic substrate-binding pocket of MmpL3, coupled to the proton transfer activity of MmpL3 and inhibited by a small molecule inhibitor SQ109. Based on the results, we propose a mechanism of allosteric coupling wherein substrate translocation by MmpL3 is coupled to the energy provided by the downhill transfer of protons. The reconstituted activities will facilitate understanding the mechanism of MmpL3-dependent transport of lipids and the discovery of new therapeutic options for Mycobacterium spp. infections.IMPORTANCEMmpL3 from Mycobacterium tuberculosis is an essential transporter involved in the assembly of the mycobacterial outer membrane. It is also an important target in undergoing efforts to discover new anti-tuberculosis drugs effective against multidrug-resistant strains spreading in human populations. The recent breakthrough structural studies uncovered features of MmpL3 that suggested a possible lipid transport mechanism. In this study, we reconstituted and characterized the lipid transport activity of MmpL3 and demonstrated that this activity is blocked by MmpL3 inhibitors and substrate mimics. We further uncovered the mechanism of how the binding of a substrate in the periplasmic domain is communicated to the transmembrane proton relay of MmpL3. The uncovered mechanism and the developed assays provide new opportunities for mechanistic analyses of MmpL3 function and its inhibition.
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Affiliation(s)
- Svitlana Babii
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Lixinhao Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Anna E Grzegorzewicz
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA
| | - James C Gumbart
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
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3
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Cioccolo S, Barritt JD, Pollock N, Hall Z, Babuta J, Sridhar P, Just A, Morgner N, Dafforn T, Gould I, Byrne B. The mycobacterium lipid transporter MmpL3 is dimeric in detergent solution, SMALPs and reconstituted nanodiscs. RSC Chem Biol 2024; 5:901-913. [PMID: 39211474 PMCID: PMC11352979 DOI: 10.1039/d4cb00110a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 07/26/2024] [Indexed: 09/04/2024] Open
Abstract
The mycobacterial membrane protein large 3 (MmpL3) transports key precursor lipids to the outer membrane of Mycobacterium species. Multiple structures of MmpL3 from both M. tuberculosis and M. smegmatis in various conformational states indicate that the protein is both structurally and functionally monomeric. However, most other resistance, nodulation and cell division (RND) transporters structurally characterised to date are either dimeric or trimeric. Here we present an in depth biophysical and computational analysis revealing that MmpL3 from M. smegmatis exists as a dimer in a variety of membrane mimetic systems (SMALPs, detergent-based solution and nanodiscs). Sucrose gradient separation of MmpL3 populations from M. smegmatis, reconstituted into nanodiscs, identified monomeric and dimeric populations of the protein using laser induced liquid bead ion desorption (LILBID), a native mass spectrometry technique. Preliminary cryo-EM analysis confirmed that MmpL3 forms physiological dimers. Untargeted lipidomics experiments on membrane protein co-purified lipids revealed PE and PG lipid classes were predominant. Molecular dynamics (MD) simulations, in the presence of physiologically-relevant lipid compositions revealed the likely dimer interface.
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Affiliation(s)
- Sara Cioccolo
- Department of Life Sciences, Imperial College London Exhibition Road, South Kensington London SW7 2AZ UK
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London Shepherd's Bush London W12 0BZ UK
| | - Joseph D Barritt
- Department of Life Sciences, Imperial College London Exhibition Road, South Kensington London SW7 2AZ UK
| | - Naomi Pollock
- School of Biosciences, University of Birmingham Birmingham UK
| | - Zoe Hall
- Division of Systems Medicine, Imperial College London London UK
| | - Julia Babuta
- Division of Systems Medicine, Imperial College London London UK
| | - Pooja Sridhar
- School of Biosciences, University of Birmingham Birmingham UK
| | - Alicia Just
- Institute of Physical and Theoretical Chemistry, J.W. Goethe-University Frankfurt am Main Germany
| | - Nina Morgner
- Institute of Physical and Theoretical Chemistry, J.W. Goethe-University Frankfurt am Main Germany
| | - Tim Dafforn
- School of Biosciences, University of Birmingham Birmingham UK
| | - Ian Gould
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London Shepherd's Bush London W12 0BZ UK
| | - Bernadette Byrne
- Department of Life Sciences, Imperial College London Exhibition Road, South Kensington London SW7 2AZ UK
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4
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Berkowitz N, MacMillan A, Simmons MB, Shinde U, Purdy GE. Structural modeling and characterization of the Mycobacterium tuberculosis MmpL3 C-terminal domain. FEBS Lett 2024. [PMID: 39198717 DOI: 10.1002/1873-3468.15007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 07/29/2024] [Accepted: 08/05/2024] [Indexed: 09/01/2024]
Abstract
The Mycobacterium tuberculosis (Mtb) cell envelope provides a protective barrier against the immune response and antibiotics. The mycobacterial membrane protein large (MmpL) family of proteins export cell envelope lipids and siderophores; therefore, these proteins are important for the basic biology and pathogenicity of Mtb. In particular, MmpL3 is essential and a known drug target. Despite interest in MmpL3, the structural data in the field are incomplete. Utilizing homology modeling, AlphaFold, and biophysical techniques, we characterized the cytoplasmic C-terminal domain (CTD) of MmpL3 to better understand its structure and function. Our in silico models of the MmpL11TB and MmpL3TB CTD reveal notable features including a long unstructured linker that connects the globular domain to the last transmembrane (TM) in each transporter, charged lysine and arginine residues facing the membrane, and a C-terminal alpha helix. Our predicted overall structure enables a better understanding of these transporters.
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Affiliation(s)
- Naomi Berkowitz
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Allison MacMillan
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Marit B Simmons
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - Ujwal Shinde
- Biophysics Core Facility, Oregon Health & Science University, Portland, OR, USA
| | - Georgiana E Purdy
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
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5
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Arejan NH, Czapski DR, Buonomo JA, Boutte CC. MmpL3, Wag31 and PlrA are involved in coordinating polar growth with peptidoglycan metabolism and nutrient availability. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591792. [PMID: 38746181 PMCID: PMC11092516 DOI: 10.1101/2024.04.29.591792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Cell growth in mycobacteria involves cell wall expansion that is restricted to the cell poles. The DivIVA homolog Wag31 is required for this process, but the molecular mechanism and protein partners of Wag31 have not been described. In this study of Mycobacterium smegmatis, we identify a connection between wag31 and trehalose monomycolate (TMM) transporter mmpl3 in a suppressor screen, and show that Wag31 and polar regulator PlrA are required for MmpL3's polar localization. In addition, the localization of PlrA and MmpL3 are responsive to nutrient and energy deprivation and inhibition of peptidoglycan metabolism. We show that inhibition of MmpL3 causes delocalized cell wall metabolism, but does not delocalize MmpL3 itself. We found that cells with an MmpL3 C-terminal truncation, which is defective for localization, have only minor defects in polar growth, but are impaired in their ability to downregulate cell wall metabolism under stress. Our work suggests that, in addition to its established function in TMM transport, MmpL3 has a second function in regulating global cell wall metabolism in response to stress. Our data are consistent with a model in which the presence of TMMs in the periplasm stimulates polar elongation, and in which the connection between Wag31, PlrA and the C-terminus of MmpL3 is involved in detecting and responding to stress in order to coordinate synthesis of the different layers of the mycobacterial cell wall in changing conditions.
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Affiliation(s)
| | - Desiree R Czapski
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Joseph A Buonomo
- Department of Chemistry and Biochemistry, University of Texas, Arlington
| | - Cara C Boutte
- Department of Biology, University of Texas, Arlington
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6
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Sodani M, Misra CS, Nigam G, Fatima Z, Kulkarni S, Rath D. MSMEG_0311 is a conserved essential polar protein involved in mycobacterium cell wall metabolism. Int J Biol Macromol 2024; 260:129583. [PMID: 38242409 DOI: 10.1016/j.ijbiomac.2024.129583] [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: 11/23/2023] [Revised: 01/16/2024] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
Cell wall synthesis and cell division are two closely linked pathways in a bacterial cell which distinctly influence the growth and survival of a bacterium. This requires an appreciable coordination between the two processes, more so, in case of mycobacteria with an intricate multi-layered cell wall structure. In this study, we investigated a conserved gene cluster using CRISPR-Cas12 based gene silencing technology to show that knockdown of most of the genes in this cluster leads to growth defects. Investigating conserved genes is important as they likely perform vital cellular functions and the functional insights on such genes can be extended to other mycobacterial species. We characterised one of the genes in the locus, MSMEG_0311. The repression of this gene not only imparts severe growth defect but also changes colony morphology. We demonstrate that the protein preferentially localises to the polar region and investigate its influence on the polar growth of the bacillus. A combination of permeability and drug susceptibility assay strongly suggests a cell wall associated function of this gene which is also corroborated by transcriptomic analysis of the knockdown where a number of cell wall associated genes, particularly iniA and sigF regulon get altered. Considering the gene is highly conserved across mycobacterial species and appears to be essential for growth, it may serve as a potential drug target.
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Affiliation(s)
- Megha Sodani
- Radiation Medicine Centre, Medical Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India
| | - Chitra S Misra
- Applied Genomics Section, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Gaurav Nigam
- Amity Institute of Biotechnology, Amity University Haryana, Gurugram, India
| | - Zeeshan Fatima
- Amity Institute of Biotechnology, Amity University Haryana, Gurugram, India; Department of Laboratory Medicine, Faculty of Applied Medical Sciences, University of Bisha, Bisha, Saudi Arabia
| | - Savita Kulkarni
- Radiation Medicine Centre, Medical Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India.
| | - Devashish Rath
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra, India; Applied Genomics Section, Bio-Science Group, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India.
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7
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Ge Y, Luo Q, Liu L, Shi Q, Zhang Z, Yue X, Tang L, Liang L, Hu J, Ouyang W. S288T mutation altering MmpL3 periplasmic domain channel and H-bond network: a novel dual drug resistance mechanism. J Mol Model 2024; 30:39. [PMID: 38224406 DOI: 10.1007/s00894-023-05814-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 12/18/2023] [Indexed: 01/16/2024]
Abstract
CONTEXT Mycobacterial membrane proteins Large 3 (MmpL3) is responsible for the transport of mycobacterial acids out of cell membrane to form cell wall, which is essential for the survival of Mycobacterium tuberculosis (Mtb) and has become a potent anti-tuberculosis target. SQ109 is an ethambutol (EMB) analogue, as a novel anti-tuberculosis drug, can effectively inhibit MmpL3, and has completed phase 2b-3 clinical trials. Drug resistance has always been the bottleneck problem in clinical treatment of tuberculosis. The S288T mutant of MmpL3 shows significant resistance to the inhibitor SQ109, while the specific action mechanism remains unclear. The results show that MmpL3 S288T mutation causes local conformational change with little effect on the global structure. With MmpL3 bound by SQ109 inhibitor, the distance between D710 and R715 increases resulting in H-bond destruction, but their interactions and proton transfer function are still restored. In addition, the rotation of Y44 in the S288T mutant leads to an obvious bend in the periplasmic domain channel and an increased number of contact residues, reducing substrate transport efficiency. This work not only provides a possible dual drug resistance mechanism of MmpL3 S288T mutant but also aids the development of novel anti-tuberculosis inhibitors. METHODS In this work, molecular dynamics (MD) and quantum mechanics (QM) simulations both were performed to compare inhibitor (i.e., SQ109) recognition, motion characteristics, and H-bond energy change of MmpL3 after S288T mutation. In addition, the WT_SQ109 complex structure was obtained by molecular docking program (Autodock 4.2); Molecular Mechanics/ Poisson Boltzmann Surface Area (MM-PBSA) and Solvated Interaction Energy (SIE) methods were used to calculate the binding free energies (∆Gbind); Geometric criteria were used to analyze the changes of hydrogen bond networks.
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Affiliation(s)
- Yutong Ge
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Qing Luo
- Faculty of Applied Sciences, Macao Polytechnic University, Macao, 999078, China
| | - Ling Liu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Quanshan Shi
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Zhigang Zhang
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China
| | - Xinru Yue
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Lingkai Tang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Li Liang
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China
| | - Jianping Hu
- Key Laboratory of Medicinal and Edible Plants Resources Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China.
| | - Weiwei Ouyang
- Department of Thoracic Oncology, Affiliated Cancer Hospital, Guizhou Medical University, Guiyang, China.
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8
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Couston J, Guo Z, Wang K, Gourdon P, Blaise M. Cryo-EM structure of the trehalose monomycolate transporter, MmpL3, reconstituted into peptidiscs. Curr Res Struct Biol 2023; 6:100109. [PMID: 38034087 PMCID: PMC10682824 DOI: 10.1016/j.crstbi.2023.100109] [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: 09/21/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 12/02/2023] Open
Abstract
Mycobacteria have an atypical thick and waxy cell wall. One of the major building blocks of such mycomembrane is trehalose monomycolate (TMM). TMM is a mycolic acid ester of trehalose that possesses long acyl chains with up to 90 carbon atoms. TMM represents an essential component of mycobacteria and is synthesized in the cytoplasm, and then flipped over the plasma membrane by a specific transporter known as MmpL3. Over the last decade, MmpL3 has emerged as an attractive drug target to combat mycobacterial infections. Recent three-dimensional structures of MmpL3 determined by X-ray crystallography and cryo-EM have increased our understanding of the TMM transport, and the mode of action of inhibiting compounds. These structures were obtained in the presence of detergent and/or in a lipidic environment. In this study, we demonstrate the possibility of obtaining a high-quality cryo-EM structure of MmpL3 without any presence of detergent through the reconstitution of the protein into peptidiscs. The structure was determined at an overall resolution of 3.2 Å and demonstrates that the overall structure of MmpL3 is preserved as compared to previous structures. Further, the study identified a new structural arrangement of the linker that fuses the two subdomains of the transmembrane domain, suggesting the feature may serve a role in the transport process.
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Affiliation(s)
- Julie Couston
- IRIM, CNRS, University of Montpellier, Montpellier, France
| | - Zongxin Guo
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark
| | - Kaituo Wang
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark
| | - Pontus Gourdon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200, Copenhagen N, Denmark
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, SE-22100, Lund, Sweden
| | - Mickaël Blaise
- IRIM, CNRS, University of Montpellier, Montpellier, France
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9
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Vasudevan N, Motiwala Z, Ramesh R, Wagh SB, Shingare RD, Katte R, Anand A, Choudhary S, Kumar A, Gokhale RS, Kulkarni KA, Reddy DS. Synthesis, biological evaluation and docking studies of silicon incorporated diarylpyrroles as MmpL3 inhibitors: An effective strategy towards development of potent anti-tubercular agents. Eur J Med Chem 2023; 259:115633. [PMID: 37524010 DOI: 10.1016/j.ejmech.2023.115633] [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: 04/29/2023] [Revised: 07/03/2023] [Accepted: 07/09/2023] [Indexed: 08/02/2023]
Abstract
Growing global demand for new molecules to treat tuberculosis has created an urgent need to develop novel strategies to combat the menace. BM212 related compounds were found to be potent anti-TB agents and they inhibit mycolic acid transporter, MmpL3, a known potent drug target from Mycobacterium tuberculosis. In order to enhance their inhibitory potency, several silicon analogues of diarylpyrroles related to BM212 were designed, synthesized, and evaluated for anti-tubercular activities. In Alamar blue assay, most of the silicon-incorporated compounds were found to be more potent than the parent compound (BM212), against Mycobacterium tuberculosis (MIC = 1.7 μM, H37Rv). Docking results from the crystal structure of MmpL3 and silicon analogues as pharmacophore model also strongly correlate with the biological assays and suggest that the incorporation of silicon in the inhibitor scaffold could enhance their potency by stabilizing the hydrophobic residues at the binding pocket. The best docking hit, compound 12 showed an MIC of 0.1 μM against H37Rv with an acceptable in vitro ADME profile and excellent selectivity index. Overall, the present study indicates that, the designed silicon analogues, especially compound 12 could be a good inhibitor for an intrinsically flexible drug-binding pocket of MmpL3 and has potential for further development as anti-tubercular agents.
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Affiliation(s)
- N Vasudevan
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Zenia Motiwala
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Remya Ramesh
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sachin B Wagh
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Rahul D Shingare
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Revansiddha Katte
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India
| | - Amitesh Anand
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sushil Choudhary
- CSIR-Indian Institute of Integrative Medicine, Post Bag No. 3, Canal Rd, Jammu, 180001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Ajay Kumar
- CSIR-Indian Institute of Integrative Medicine, Post Bag No. 3, Canal Rd, Jammu, 180001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Rajesh S Gokhale
- CSIR-Institute of Genomics and Integrative Biology, Mathura Road, New Delhi, 110025, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India; Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411008, India; Immunometabolism Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Kiran A Kulkarni
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| | - D Srinivasa Reddy
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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10
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Meikle V, Zhang L, Niederweis M. Intricate link between siderophore secretion and drug efflux in Mycobacterium tuberculosis. Antimicrob Agents Chemother 2023; 67:e0162922. [PMID: 37676015 PMCID: PMC10583673 DOI: 10.1128/aac.01629-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 06/30/2023] [Indexed: 09/08/2023] Open
Abstract
Drug-resistant Mycobacterium tuberculosis is a worldwide health-care problem rendering current tuberculosis (TB) drugs ineffective. Drug efflux is an important mechanism in bacterial drug resistance. The MmpL4 and MmpL5 transporters form functionally redundant complexes with their associated MmpS4 and MmpS5 proteins and constitute the inner membrane components of an essential siderophore secretion system of M. tuberculosis. Inactivating siderophore secretion is toxic for M. tuberculosis due to self-poisoning at low-iron conditions and leads to a strong virulence defect in mice. In this study, we show that M. tuberculosis mutants lacking components of the MmpS4-MmpL4 and MmpS5-MmpL5 systems are more susceptible to bedaquiline, clofazimine, and rifabutin, important drugs for treatment of drug-resistant TB. While genetic deletion experiments revealed similar functions of the MmpL4 and MmpL5 transporters in siderophore and drug secretion, complementation experiments indicated that the MmpS4-MmpL4 proteins alone are not sufficient to restore drug efflux in an M. tuberculosis mutant lacking both operons, in contrast to MmpS5-MmpL5. Importantly, an M. tuberculosis mutant lacking the recently discovered periplasmic Rv0455c protein, which is also essential for siderophore secretion, is more susceptible to the same drugs. These results reveal a promising target for the development of dual-function TB drugs, which might poison M. tuberculosis by blocking siderophore secretion and synergize with other drugs by impairing drug efflux.
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Affiliation(s)
- Virginia Meikle
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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11
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Palčeková Z, Obregón-Henao A, De K, Walz A, Lam H, Philp J, Angala SK, Patterson J, Pearce C, Zuberogoitia S, Avanzi C, Nigou J, McNeil M, Muñoz Gutiérrez JF, Gilleron M, Wheat WH, Gonzalez-Juarrero M, Jackson M. Role of succinyl substituents in the mannose-capping of lipoarabinomannan and control of inflammation in Mycobacterium tuberculosis infection. PLoS Pathog 2023; 19:e1011636. [PMID: 37669276 PMCID: PMC10503756 DOI: 10.1371/journal.ppat.1011636] [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: 11/23/2022] [Revised: 09/15/2023] [Accepted: 08/25/2023] [Indexed: 09/07/2023] Open
Abstract
The covalent modification of bacterial (lipo)polysaccharides with discrete substituents may impact their biosynthesis, export and/or biological activity. Whether mycobacteria use a similar strategy to control the biogenesis of its cell envelope polysaccharides and modulate their interaction with the host during infection is unknown despite the report of a number of tailoring substituents modifying the structure of these glycans. Here, we show that discrete succinyl substituents strategically positioned on Mycobacterium tuberculosis (Mtb) lipoarabinomannan govern the mannose-capping of this lipoglycan and, thus, much of the biological activity of the entire molecule. We further show that the absence of succinyl substituents on the two main cell envelope glycans of Mtb, arabinogalactan and lipoarabinomannan, leads to a significant increase of pro-inflammatory cytokines and chemokines in infected murine and human macrophages. Collectively, our results validate polysaccharide succinylation as a critical mechanism by which Mtb controls inflammation.
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Affiliation(s)
- Zuzana Palčeková
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Andrés Obregón-Henao
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kavita De
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Amanda Walz
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Ha Lam
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jamie Philp
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Shiva Kumar Angala
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Johnathan Patterson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Camron Pearce
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Sophie Zuberogoitia
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Charlotte Avanzi
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Jérôme Nigou
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Michael McNeil
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Juan F. Muñoz Gutiérrez
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Martine Gilleron
- Institut de Pharmacologie et de Biologie Structurale, IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - William H. Wheat
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
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12
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Carbone J, Paradis NJ, Bennet L, Alesiani MC, Hausman KR, Wu C. Inhibition Mechanism of Anti-TB Drug SQ109: Allosteric Inhibition of TMM Translocation of Mycobacterium Tuberculosis MmpL3 Transporter. J Chem Inf Model 2023; 63:5356-5374. [PMID: 37589273 PMCID: PMC10466384 DOI: 10.1021/acs.jcim.3c00616] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Indexed: 08/18/2023]
Abstract
The mycolic acid transporter MmpL3 is driven by proton motive forces (PMF) and functions via an antiport mechanism. Although the crystal structures of the Mycobacterium smegmatis MmpL3 transporter alone and in complex with a trehalose monomycolate (TMM) substrate and an antituberculosis drug candidate SQ109 under Phase 2b-3 Clinical Trials are available, no water and no conformational change in MmpL3 were observed in these structures to explain SQ109's inhibition mechanism of proton and TMM transportation. In this study, molecular dynamics simulations of both apo form and inhibitor-bound MmpL3 in an explicit membrane were used to decipher the inhibition mechanism of SQ109. In the apo system, the close-open motion of the two TM domains, likely driven by the proton translocation, drives the close-open motion of the two PD domains, presumably allowing for TMM translocation. In contrast, in the holo system, the two PD domains are locked in a closed state, and the two TM domains are locked in an off pathway wider open state due to the binding of the inhibitor. Consistent with the close-open motion of the two PD domains, TMM entry size changes in the apo system, likely loading and moving the TMM, but does not vary much in the holo system and probably impair the movement of the TMM. Furthermore, we observed that water molecules passed through the central channel of the MmpL3 transporter to the cytoplasmic side in the apo system but not in the holo system, with a mean passing time of ∼135 ns. Because water wires play an essential role in transporting protons, our findings shed light on the importance of PMF in driving the close-open motion of the two TM domains. Interestingly, the key channel residues involved in water passage display considerable overlap with conserved residues within the MmpL protein family, supporting their critical function role.
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Affiliation(s)
| | | | | | - Mark C. Alesiani
- Department of Chemistry & Biochemistry,
College of Science and Mathematics, Rowan
University, Glassboro, New Jersey 08028, United States
| | - Katherine R. Hausman
- Department of Chemistry & Biochemistry,
College of Science and Mathematics, Rowan
University, Glassboro, New Jersey 08028, United States
| | - Chun Wu
- Department of Chemistry & Biochemistry,
College of Science and Mathematics, Rowan
University, Glassboro, New Jersey 08028, United States
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13
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North EJ, Schwartz CP, Zgurskaya HI, Jackson M. Recent advances in mycobacterial membrane protein large 3 inhibitor drug design for mycobacterial infections. Expert Opin Drug Discov 2023; 18:707-724. [PMID: 37226498 PMCID: PMC10330604 DOI: 10.1080/17460441.2023.2218082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/22/2023] [Indexed: 05/26/2023]
Abstract
INTRODUCTION Tuberculosis and nontuberculous mycobacterial infections are notoriously difficult to treat, requiring long-courses of intensive multi-drug therapies associated with adverse side effects. To identify better therapeutics, whole cell screens have identified novel pharmacophores, a surprisingly high number of which target an essential lipid transporter known as MmpL3. AREAS COVERED This paper summarizes what is known about MmpL3, its mechanism of lipid transport and therapeutic potential, and provides an overview of the different classes of MmpL3 inhibitors currently under development. It further describes the assays available to study MmpL3 inhibition by these compounds. EXPERT OPINION MmpL3 has emerged as a target of high therapeutic value. Accordingly, several classes of MmpL3 inhibitors are currently under development with one drug candidate (SQ109) having undergone a Phase 2b clinical study. The hydrophobic character of most MmpL3 series identified to date seems to drive antimycobacterial potency resulting in poor bioavailability, which is a significant impediment to their development. There is also a need for more high-throughput and informative assays to elucidate the precise mechanism of action of MmpL3 inhibitors and drive the rational optimization of analogues.
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Affiliation(s)
- E. Jeffrey North
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Chris P. Schwartz
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Helen I. Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA
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14
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Li Y, Acharya A, Yang L, Liu J, Tajkhorshid E, Zgurskaya HI, Jackson M, Gumbart JC. Insights into substrate transport and water permeation in the mycobacterial transporter MmpL3. Biophys J 2023; 122:2342-2352. [PMID: 36926696 PMCID: PMC10257117 DOI: 10.1016/j.bpj.2023.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/04/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
Mycobacteria, such as Mycobacterium tuberculosis, are characterized by a uniquely thick and waxy cell envelope that consists of two membranes, with a variety of mycolates comprising their outer membrane (OM). The protein Mycobacterial membrane protein Large 3 (MmpL3) is responsible for the transport of a primary OM component, trehalose monomycolate (TMM), from the inner (cytoplasmic) membrane (IM) to the periplasmic space, a process driven by the proton gradient. Although multiple structures of MmpL3 with bound substrates have been solved, the exact pathway(s) for TMM or proton transport remains elusive. Here, employing molecular dynamics simulations we investigate putative pathways for either transport species. We hypothesized that MmpL3 will cycle through similar conformational states as the related transporter AcrB, which we used as targets for modeling the conformation of MmpL3. A continuous water pathway through the transmembrane region was found in one of these states, illustrating a putative pathway for protons. Additional equilibrium simulations revealed that TMM can diffuse from the membrane into a binding pocket in MmpL3 spontaneously. We also found that acetylation of TMM, which is required for transport, makes it more stable within MmpL3's periplasmic cavity compared with the unacetylated form.
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Affiliation(s)
- Yupeng Li
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - Atanu Acharya
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia
| | - Lixinhao Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia
| | - Jinchan Liu
- Department of Molecular Biophysics and Biochemistry (MB&B), Yale University, New Haven, Connecticut
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Resource for Macromolecular Modeling and Visualization, Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, Illinois; Center for Biophysics and Quantitative Biology, University of Illinois Urbana-Champaign, Urbana, Illinois; Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - James C Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia; School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia.
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15
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Kapp E, Calitz H, Streicher EM, Dippenaar A, Egieyeh S, Jordaan A, Warner DF, Joubert J, Malan SF, Sampson SL. Discovery and biological evaluation of an adamantyl-amide derivative with likely MmpL3 inhibitory activity. Tuberculosis (Edinb) 2023; 141:102350. [PMID: 37244249 DOI: 10.1016/j.tube.2023.102350] [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: 11/01/2022] [Revised: 05/02/2023] [Accepted: 05/07/2023] [Indexed: 05/29/2023]
Abstract
A series of molecules containing bulky lipophilic scaffolds was screened for activity against Mycobacterium tuberculosis and a number of compounds with antimycobacterial activity were identified. The most active compound, (2E)-N-(adamantan-1-yl)-3-phenylprop-2-enamide (C1), has a low micromolar minimum inhibitory concentration, low cytotoxicity (therapeutic index = 32.26), low mutation frequency and is active against intracellular Mycobacterium tuberculosis. Whole genome sequencing of mutants resistant to C1 showed a mutation in mmpL3 which may point to the involvement of MmpL3 in the antimycobacterial activity of the compound. In silico mutagenesis and molecular modelling studies were performed to better understand the binding of C1 within MmpL3 and the role that the specific mutation may play in the interaction at protein level. These analyses revealed that the mutation increases the energy required for binding of C1 within the protein translocation channel of MmpL3. The mutation also decreases the solvation energy of the protein, suggesting that the mutant protein might be more solvent-accessible, thereby restricting its interaction with other molecules. The results reported here describe a new molecule that may interact with the MmpL3 protein, providing insights into the effect of mutations on protein-ligand interactions and enhancing our understanding of this essential protein as a priority drug target.
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Affiliation(s)
- Erika Kapp
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Hanri Calitz
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
| | - Elizabeth M Streicher
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
| | - Anzaan Dippenaar
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa; Global Health Institute, Department of Family Medicine and Population Health, Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium; Gouverneur Kinsbergencentrum, Doornstraat 331, 2610, Wilrijk, Belgium.
| | - Samuel Egieyeh
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Audrey Jordaan
- Molecular Mycobacteriology Research Unit, DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa.
| | - Digby F Warner
- Molecular Mycobacteriology Research Unit, DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa.
| | - Jacques Joubert
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Sarel F Malan
- School of Pharmacy, Faculty of Natural Sciences, University of the Western Cape, Cape Town, South Africa; University of the Western Cape, Private Bag x17, Bellville, 7535, South Africa.
| | - Samantha L Sampson
- DSI/NRF Centre of Excellence for Biomedical Tuberculosis Research/South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, P.O. Box 241, Cape Town, 8000, South Africa.
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16
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Williams JT, Abramovitch RB. Molecular Mechanisms of MmpL3 Function and Inhibition. Microb Drug Resist 2023; 29:190-212. [PMID: 36809064 PMCID: PMC10171966 DOI: 10.1089/mdr.2021.0424] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Mycobacteria species include a large number of pathogenic organisms such as Mycobacterium tuberculosis, Mycobacterium leprae, and various non-tuberculous mycobacteria. Mycobacterial membrane protein large 3 (MmpL3) is an essential mycolic acid and lipid transporter required for growth and cell viability. In the last decade, numerous studies have characterized MmpL3 with respect to protein function, localization, regulation, and substrate/inhibitor interactions. This review summarizes new findings in the field and seeks to assess future areas of research in our rapidly expanding understanding of MmpL3 as a drug target. An atlas of known MmpL3 mutations that provide resistance to inhibitors is presented, which maps amino acid substitutions to specific structural domains of MmpL3. In addition, chemical features of distinct classes of Mmpl3 inhibitors are compared to provide insights into shared and unique features of varied MmpL3 inhibitors.
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Affiliation(s)
- John T Williams
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Robert B Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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17
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Update on the Discovery of Efflux Pump Inhibitors against Critical Priority Gram-Negative Bacteria. Antibiotics (Basel) 2023; 12:antibiotics12010180. [PMID: 36671381 PMCID: PMC9854755 DOI: 10.3390/antibiotics12010180] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 01/18/2023] Open
Abstract
Antimicrobial resistance (AMR) has become a major problem in public health leading to an estimated 4.95 million deaths in 2019. The selective pressure caused by the massive and repeated use of antibiotics has led to bacterial strains that are partially or even entirely resistant to known antibiotics. AMR is caused by several mechanisms, among which the (over)expression of multidrug efflux pumps plays a central role. Multidrug efflux pumps are transmembrane transporters, naturally expressed by Gram-negative bacteria, able to extrude and confer resistance to several classes of antibiotics. Targeting them would be an effective way to revive various options for treatment. Many efflux pump inhibitors (EPIs) have been described in the literature; however, none of them have entered clinical trials to date. This review presents eight families of EPIs active against Escherichia coli or Pseudomonas aeruginosa. Structure-activity relationships, chemical synthesis, in vitro and in vivo activities, and pharmacological properties are reported. Their binding sites and their mechanisms of action are also analyzed comparatively.
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18
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Bhattarai P, Hegde P, Li W, Prathipati PK, Stevens CM, Yang L, Zhou H, Pandya A, Cunningham K, Grissom J, Roman Sotelo M, Sowards M, Calisto L, Destache CJ, Rocha-Sanchez S, Gumbart JC, Zgurskaya HI, Jackson M, North EJ. Structural Determinants of Indole-2-carboxamides: Identification of Lead Acetamides with Pan Antimycobacterial Activity. J Med Chem 2023; 66:170-187. [PMID: 36563291 PMCID: PMC10010622 DOI: 10.1021/acs.jmedchem.2c00352] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is one of the leading causes of death in developing countries. Non-tuberculous mycobacteria (NTM) infections are rising and prey upon patients with structural lung diseases such as chronic obstructive pulmonary disease (COPD) and cystic fibrosis. All mycobacterial infections require lengthy treatment regimens with undesirable side effects. Therefore, new antimycobacterial compounds with novel mechanisms of action are urgently needed. Published indole-2-carboxamides (IC) with suggested inhibition of the essential transporter MmpL3 showed good potency against whole-cell M.tb, yet had poor aqueous solubility. This project focused on retaining the required MmpL3 inhibitory pharmacophore and increasing the molecular heteroatom percentage by reducing lipophilic atoms. We evaluated pyrrole, mandelic acid, imidazole, and acetamide functional groups coupled to lipophilic head groups, where lead acetamide-based compounds maintained high potency against mycobacterial pathogens, had improved in vitro ADME profiles over their indole-2-carboxamide analogs, were non-cytotoxic, and were determined to be MmpL3 inhibitors.
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Affiliation(s)
- Pankaj Bhattarai
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Pooja Hegde
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado80523, United States
| | - Pavan Kumar Prathipati
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Casey M Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma73019, United States
| | - Lixinhao Yang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Hinman Zhou
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Amit Pandya
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Katie Cunningham
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Jenny Grissom
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Mariaelena Roman Sotelo
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Melanie Sowards
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Lilian Calisto
- Department of Oral Biology, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Christopher J Destache
- Department of Pharmacy Practice, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - Sonia Rocha-Sanchez
- Department of Oral Biology, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
| | - James C Gumbart
- School of Physics and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia30332, United States
| | - Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma73019, United States
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado80523, United States
| | - E Jeffrey North
- Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska68178, United States
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19
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Ochsner UA, De Groote MA, Jarvis TC, Liu H, Youmans T, Hoang T, Ribble W, Day J, Li W, Pearce C, Walz A, Panthi CM, Rimal B, Stevens CM, Zgurskaya HI, Jackson M, Ordway D, Gonzalez-Juarrero M, Sun X, Lamichhane G, Mason C. Microbiological profile, preclinical pharmacokinetics and efficacy of CRS0393, a novel antimycobacterial agent targeting MmpL3. Tuberculosis (Edinb) 2023; 138:102288. [PMID: 36470124 PMCID: PMC9892229 DOI: 10.1016/j.tube.2022.102288] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 11/30/2022]
Abstract
The benzothiazole amide CRS0393 demonstrated excellent in vitro activity against nontuberculous mycobacteria (NTM), including M. abscessus isolates from cystic fibrosis (CF) patients, with minimum inhibitory concentrations (MICs) of ≤0.03-0.5 μg/mL. The essential transport protein MmpL3 was confirmed as the target via analysis of spontaneous resistant mutants and further biological profiling. In mouse pharmacokinetic studies, intratracheal instillation of a single dose of CRS0393 resulted in high concentrations of drug in epithelial lining fluid (ELF) and lung tissue, which remained above the M. abscessus MIC for at least 9 hours post-dose. This exposure resulted in a penetration ratio of 261 for ELF and 54 for lung tissue relative to plasma. CRS0393 showed good oral bioavailability, particularly when formulated in kolliphor oil, with a lung-to-plasma penetration ratio ranging from 0.5 to 4. CRS0393 demonstrated concentration-dependent reduction of intracellular M. abscessus in a THP-1 macrophage infection model. CRS0393 was well tolerated following intranasal administration (8 mg/kg) or oral dosing (25 mg/kg) once daily for 28 days in dexamethasone-treated C3HeB/FeJ mice. Efficacy against M. abscessus strain 103 was achieved via the intranasal route, while oral dosing will need further optimization. CRS0393 holds promise for development as a novel agent with broad antimycobacterial activity.
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Affiliation(s)
| | | | | | - Hang Liu
- Crestone, Inc., 6075 Longbow Dr, Boulder, CO, USA
| | | | - Teresa Hoang
- Crestone, Inc., 6075 Longbow Dr, Boulder, CO, USA
| | - Wendy Ribble
- Crestone, Inc., 6075 Longbow Dr, Boulder, CO, USA
| | - Joshua Day
- Crestone, Inc., 6075 Longbow Dr, Boulder, CO, USA
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Camron Pearce
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Amanda Walz
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Chandra M Panthi
- Johns Hopkins University, 1550 Orleans Street, Baltimore, MD, USA
| | - Binayak Rimal
- Johns Hopkins University, 1550 Orleans Street, Baltimore, MD, USA
| | - Casey M Stevens
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, USA
| | - Helen I Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Diane Ordway
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, 200 West Lake Street, Colorado State University, Fort Collins, CO, USA
| | - Xicheng Sun
- Crestone, Inc., 6075 Longbow Dr, Boulder, CO, USA
| | - Gyanu Lamichhane
- Johns Hopkins University, 1550 Orleans Street, Baltimore, MD, USA
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20
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Yan W, Zheng Y, Dou C, Zhang G, Arnaout T, Cheng W. The pathogenic mechanism of Mycobacterium tuberculosis: implication for new drug development. MOLECULAR BIOMEDICINE 2022; 3:48. [PMID: 36547804 PMCID: PMC9780415 DOI: 10.1186/s43556-022-00106-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 11/15/2022] [Indexed: 12/24/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is a tenacious pathogen that has latently infected one third of the world's population. However, conventional TB treatment regimens are no longer sufficient to tackle the growing threat of drug resistance, stimulating the development of innovative anti-tuberculosis agents, with special emphasis on new protein targets. The Mtb genome encodes ~4000 predicted proteins, among which many enzymes participate in various cellular metabolisms. For example, more than 200 proteins are involved in fatty acid biosynthesis, which assists in the construction of the cell envelope, and is closely related to the pathogenesis and resistance of mycobacteria. Here we review several essential enzymes responsible for fatty acid and nucleotide biosynthesis, cellular metabolism of lipids or amino acids, energy utilization, and metal uptake. These include InhA, MmpL3, MmaA4, PcaA, CmaA1, CmaA2, isocitrate lyases (ICLs), pantothenate synthase (PS), Lysine-ε amino transferase (LAT), LeuD, IdeR, KatG, Rv1098c, and PyrG. In addition, we summarize the role of the transcriptional regulator PhoP which may regulate the expression of more than 110 genes, and the essential biosynthesis enzyme glutamine synthetase (GlnA1). All these enzymes are either validated drug targets or promising target candidates, with drugs targeting ICLs and LAT expected to solve the problem of persistent TB infection. To better understand how anti-tuberculosis drugs act on these proteins, their structures and the structure-based drug/inhibitor designs are discussed. Overall, this investigation should provide guidance and support for current and future pharmaceutical development efforts against mycobacterial pathogenesis.
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Affiliation(s)
- Weizhu Yan
- grid.412901.f0000 0004 1770 1022Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041 China
| | - Yanhui Zheng
- grid.412901.f0000 0004 1770 1022Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041 China
| | - Chao Dou
- grid.412901.f0000 0004 1770 1022Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041 China
| | - Guixiang Zhang
- grid.13291.380000 0001 0807 1581Division of Gastrointestinal Surgery, Department of General Surgery and Gastric Cancer center, West China Hospital, Sichuan University, No. 37. Guo Xue Xiang, Chengdu, 610041 China
| | - Toufic Arnaout
- Kappa Crystals Ltd., Dublin, Ireland ,MSD Dunboyne BioNX, Co. Meath, Ireland
| | - Wei Cheng
- grid.412901.f0000 0004 1770 1022Division of Respiratory and Critical Care Medicine, Respiratory Infection and Intervention Laboratory of Frontiers Science Center for Disease-Related Molecular Network, State Key Laboratory of Biotherapy, West China Hospital of Sichuan University, Chengdu, 610041 China
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21
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Imran M, Arora MK, Chaudhary A, Khan SA, Kamal M, Alshammari MM, Alharbi RM, Althomali NA, Alzimam IM, Alshammari AA, Alharbi BH, Alshengeti A, Alsaleh AA, Alqahtani SA, Rabaan AA. MmpL3 Inhibition as a Promising Approach to Develop Novel Therapies against Tuberculosis: A Spotlight on SQ109, Clinical Studies, and Patents Literature. Biomedicines 2022; 10:2793. [PMID: 36359313 PMCID: PMC9687596 DOI: 10.3390/biomedicines10112793] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 08/13/2023] Open
Abstract
Tuberculosis (TB) is accountable for considerable global morbidity and mortality. Effective TB therapy with multiple drugs completes in about six months. The longer duration of TB therapy challenges patient compliance and contributes to treatment collapse and drug resistance (DR) progress. Therefore, new medications with an innovative mechanism of action are desperately required to shorten the TB therapy's duration and effective TB control. The mycobacterial membrane protein Large 3 (MmpL3) is a novel, mycobacteria-conserved and recognized promiscuous drug target used in the development of better treatments for multi-drug resistance TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). This article spotlights MmpL3, the clinical studies of its inhibitor (SQ109), and the patent literature. The literature on MmpL3 inhibitors was searched on PubMed and freely available patent databases (Espacenet, USPTO, and PatentScope). SQ109, an analog of ethambutol (EMB), is an established MmpL3 inhibitor and has completed Phase 2b-3 clinical trials. Infectex and Sequella are developing orally active SQ109 in partnership to treat MDR pulmonary TB. SQ109 has demonstrated activity against drug-sensitive (DS) and drug-resistant (DR) Mycobacterium tuberculosis (Mtb) and a synergistic effect with isoniazid (INH), rifampicin (RIF), clofazimine (CFZ), and bedaquiline (BNQ). The combination of SQ109, clofazimine, bedaquiline, and pyrazinamide (PZA) has been patented due to its excellent anti-TB activity against MDR-TB, XDR-TB, and latent-TB. The combinations of SQ109 with other anti-TB drugs (chloroquine, hydroxychloroquine, and sutezolid) have also been claimed in the patent literature. SQ109 is more potent than EMB and could substitute EMB in the intensive stage of TB treatment with the three- or four-drug combination. Developing MmpL3 inhibitors is a promising approach to fighting the challenges associated with DS-TB and DR-TB. The authors foresee MmpL3 inhibitors such as SQ109 as future drugs for TB treatment.
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Affiliation(s)
- Mohd. Imran
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia
| | - Mandeep Kumar Arora
- School of Pharmaceutical and Population Health Informatics, DIT University, Dehradun 248009, India
| | - Anurag Chaudhary
- Department of Pharmaceutical Technology, Meerut Institute of Engineering and Technology, Meerut 250005, India
| | - Shah Alam Khan
- Department of Pharmaceutical Chemistry, College of Pharmacy, National University of Science and Technology, Muscat 130, Oman
| | - Mehnaz Kamal
- Department of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Manal Mutlaq Alshammari
- Pharmacy Department, Hotat Bani Tamim General Hospital, Hotat Bani Tamim 16631, Saudi Arabia
| | | | | | | | | | | | - Amer Alshengeti
- Department of Pediatrics, College of Medicine, Taibah University, Al-Madinah 41491, Saudi Arabia
- Department of Infection Prevention and Control, Prince Mohammad Bin Abdulaziz Hospital, National Guard Health Affairs, Al-Madinah 41491, Saudi Arabia
| | - Abdulmonem A. Alsaleh
- Clinical Laboratory Science Department, Mohammed Al-Mana College for Medical Sciences, Dammam 34222, Saudi Arabia
| | | | - Ali A. Rabaan
- Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran 31311, Saudi Arabia
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
- Department of Public Health and Nutrition, The University of Haripur, Haripur 22610, Pakistan
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22
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Novel chemical entities inhibiting Mycobacterium tuberculosis growth identified by phenotypic high-throughput screening. Sci Rep 2022; 12:14879. [PMID: 36050506 PMCID: PMC9435431 DOI: 10.1038/s41598-022-19192-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 08/25/2022] [Indexed: 11/08/2022] Open
Abstract
We performed a high-throughput phenotypic whole cell screen of Mycobacterium tuberculosis against a diverse chemical library of approximately 100,000 compounds from the AbbVie corporate collection and identified 24 chemotypes with anti-tubercular activity. We selected two series for further exploration and conducted structure-activity relationship studies with new analogs for the 4-phenyl piperidines (4PP) and phenylcyclobutane carboxamides (PCB). Strains with mutations in MmpL3 demonstrated resistance to both compound series. We isolated resistant mutants for the two series and found mutations in MmpL3. These data suggest that MmpL3 is the target, or mechanism of resistance for both series.
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23
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Stevens CM, Babii SO, Pandya AN, Li W, Li Y, Mehla J, Scott R, Hegde P, Prathipati PK, Acharya A, Liu J, Gumbart JC, North J, Jackson M, Zgurskaya HI. Proton transfer activity of the reconstituted Mycobacterium tuberculosis MmpL3 is modulated by substrate mimics and inhibitors. Proc Natl Acad Sci U S A 2022; 119:e2113963119. [PMID: 35858440 PMCID: PMC9335285 DOI: 10.1073/pnas.2113963119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 06/03/2022] [Indexed: 01/21/2023] Open
Abstract
Transporters belonging to the Resistance-Nodulation-cell Division (RND) superfamily of proteins such as Mycobacterium tuberculosis MmpL3 and its analogs are the focus of intense investigations due to their importance in the physiology of Corynebacterium-Mycobacterium-Nocardia species and antimycobacterial drug discovery. These transporters deliver trehalose monomycolates, the precursors of major lipids of the outer membrane, to the periplasm by a proton motive force-dependent mechanism. In this study, we successfully purified, from native membranes, the full-length and the C-terminal truncated M. tuberculosis MmpL3 and Corynebacterium glutamicum CmpL1 proteins and reconstituted them into proteoliposomes. We also generated a series of substrate mimics and inhibitors specific to these transporters, analyzed their activities in the reconstituted proteoliposomes, and carried out molecular dynamics simulations of the model MmpL3 transporter at different pH. We found that all reconstituted proteins facilitate proton translocation across a phospholipid bilayer, but MmpL3 and CmpL1 differ dramatically in their responses to pH and interactions with substrate mimics and indole-2-carboxamide inhibitors. Our results further suggest that some inhibitors abolish the transport activity of MmpL3 and CmpL1 by inhibition of proton translocation.
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Affiliation(s)
- Casey M. Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Svitlana O. Babii
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Amitkumar N. Pandya
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Yupeng Li
- College of Chemistry, Jilin University, 130012 Changchun, China
- Tang Aoqing Honors Program in Science, Jilin University, 130012 Changchun, China
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jitender Mehla
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
| | - Robyn Scott
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Pooja Hegde
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Pavan K. Prathipati
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Atanu Acharya
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jinchan Liu
- College of Chemistry, Jilin University, 130012 Changchun, China
- Tang Aoqing Honors Program in Science, Jilin University, 130012 Changchun, China
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - James C. Gumbart
- School of Physics, Georgia Institute of Technology, Atlanta, GA 30332
| | - Jeffrey North
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, Omaha, NE 68178
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019
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24
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Mi J, Gong W, Wu X. Advances in Key Drug Target Identification and New Drug Development for Tuberculosis. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5099312. [PMID: 35252448 PMCID: PMC8896939 DOI: 10.1155/2022/5099312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 02/14/2022] [Indexed: 12/15/2022]
Abstract
Tuberculosis (TB) is a severe infectious disease worldwide. The increasing emergence of drug-resistant Mycobacterium tuberculosis (Mtb) has markedly hampered TB control. Therefore, there is an urgent need to develop new anti-TB drugs to treat drug-resistant TB and shorten the standard therapy. The discovery of targets of drug action will lay a theoretical foundation for new drug development. With the development of molecular biology and the success of Mtb genome sequencing, great progress has been made in the discovery of new targets and their relevant inhibitors. In this review, we summarized 45 important drug targets and 15 new drugs that are currently being tested in clinical stages and several prospective molecules that are still at the level of preclinical studies. A comprehensive understanding of the drug targets of Mtb can provide extensive insights into the development of safer and more efficient drugs and may contribute new ideas for TB control and treatment.
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Affiliation(s)
- Jie Mi
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing 100091, China
| | - Wenping Gong
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing 100091, China
| | - Xueqiong Wu
- Tuberculosis Prevention and Control Key Laboratory/Beijing Key Laboratory of New Techniques of Tuberculosis Diagnosis and Treatment, Senior Department of Tuberculosis, The 8th Medical Center of PLA General Hospital, Beijing 100091, China
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25
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Qiu W, Guo Y. Analysis of the oligomeric state of mycobacterial membrane protein large 3 and its interaction with SQ109 with native cell membrane nanoparticles system. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2022; 1864:183793. [PMID: 34655545 DOI: 10.1016/j.bbamem.2021.183793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 01/24/2023]
Abstract
Mycobacterial membrane protein large 3 (Mmpl3) as a trehalose monomycolate lipid transporter contributes to cell wall biosynthesis. Inhibition of Mmpl3 can suppress cell growth and lead to mycobacterial death. SQ109 is a hydrophobic inhibitor of Mmpl3. We have devised a detergent-free strategy to characterize the SQ109/Mmpl3 interaction using the Native Cell Membrane Nanoparticles (NCMN) system, a new method for extracting membrane proteins that better retains native lipids. The homogeneity of the Mmpl3 NCMN particles was confirmed with electron microscopy. The hydrophobic protein-ligand interaction analysis shown for Mmpl3 using the NCMN system may broadly apply to other membrane proteins.
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Affiliation(s)
- Weihua Qiu
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA.
| | - Youzhong Guo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA
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26
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Ung KL, Alsarraf H, Kremer L, Blaise M. MmpL3, the trehalose monomycolate transporter, is stable in solution in several detergents and can be reconstituted into peptidiscs. Protein Expr Purif 2021; 191:106014. [PMID: 34767949 DOI: 10.1016/j.pep.2021.106014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/04/2021] [Accepted: 11/07/2021] [Indexed: 11/24/2022]
Abstract
Mycobacteria possess a complex and waxy cell wall comprising a large panel of glycolipids. Among these, trehalose monomycolate (TMM) represents abundant and crucial components for the elaboration of the mycomembrane. TMM is synthesized in the cytoplasmic compartment and translocated across the inner membrane by the MmpL3 transporter. Inhibitors impeding TMM transport by targeting MmpL3 show great promises as new antimycobacterials. The recent X-ray or Cryo-EM structures of MmpL3 complexed to TMM or its inhibitors have shed light on the mechanisms of TMM transport and inhibition. So far, purification procedures mainly involved the use of n-Dodecyl-ß-d-Maltopyranoside to solubilize and stabilize MmpL3 from Mycobacterium smegmatis (MmpL3Msm) or Lauryl Maltose Neopentyl Glycol for MmpL3 from Mycobacterium tuberculosis. Herein, we explored the possibility to solubilize and stabilize MmpL3 with other detergents. We demonstrate that several surfactants from the ionic, non-ionic and zwitterionic classes are prone to solubilize MmpL3Msm expressed in Escherichia coli. The capacity of these detergents to stabilize MmpL3Msm was evaluated by size-exclusion chromatography and thermal stability. This study unraveled three new detergents DM, LDAO and sodium cholate that favor solubilization and stabilization of MmpL3Msm in solution. In addition, we report a protocol that allows reconstitution of MmpL3Msm into peptidiscs.
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Affiliation(s)
- Kien Lam Ung
- Université de Montpellier, IRIM, CNRS, Montpellier, France
| | - Husam Alsarraf
- Université de Montpellier, IRIM, CNRS, Montpellier, France; Department of Molecular Biology and Genetics, University of Aarhus, 8000, Aarhus, Denmark
| | - Laurent Kremer
- Université de Montpellier, IRIM, CNRS, Montpellier, France; INSERM, IRIM, Montpellier, France
| | - Mickaël Blaise
- Université de Montpellier, IRIM, CNRS, Montpellier, France.
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27
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Adams O, Deme JC, Parker JL, Fowler PW, Lea SM, Newstead S. Cryo-EM structure and resistance landscape of M. tuberculosis MmpL3: An emergent therapeutic target. Structure 2021; 29:1182-1191.e4. [PMID: 34242558 PMCID: PMC8752444 DOI: 10.1016/j.str.2021.06.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/24/2021] [Accepted: 06/14/2021] [Indexed: 11/09/2022]
Abstract
Tuberculosis (TB) is the leading cause of death from a single infectious agent and in 2019 an estimated 10 million people worldwide contracted the disease. Although treatments for TB exist, continual emergence of drug-resistant variants necessitates urgent development of novel antituberculars. An important new target is the lipid transporter MmpL3, which is required for construction of the unique cell envelope that shields Mycobacterium tuberculosis (Mtb) from the immune system. However, a structural understanding of the mutations in Mtb MmpL3 that confer resistance to the many preclinical leads is lacking, hampering efforts to circumvent resistance mechanisms. Here, we present the cryoelectron microscopy structure of Mtb MmpL3 and use it to comprehensively analyze the mutational landscape of drug resistance. Our data provide a rational explanation for resistance variants local to the central drug binding site, and also highlight a potential alternative route to resistance operating within the periplasmic domain.
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Affiliation(s)
- Oliver Adams
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Justin C Deme
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford OX1 3RE, UK; Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA
| | - Joanne L Parker
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
| | - Philip W Fowler
- Nuffield Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK; National Institute of Health Research (NIHR) Oxford Biomedical Research Centre, John Radcliffe, Oxford OX3 9DU, UK
| | - Susan M Lea
- The Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford OX1 3RE, UK; Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA.
| | - Simon Newstead
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK; The Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK.
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28
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Kolocouris A, Stampolaki M. Improved Synthesis of the Antitubercular Agent SQ109. SYNOPEN 2021. [DOI: 10.1055/a-1655-5867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
AbstractWe present here an improved procedure for the preparation of the promising antitubercular drug SQ109 that is currently in phase Ib/III of clinical trials against Mycobacterium tuberculosis. We investigated and tested the literature synthetic procedure that enables the development of structure–activity relationships and report the observed inconsistencies as well as presenting improvements or novelties for the more efficient preparation of SQ109. Most significantly we applied a novel reduction step of the aminoamide precursor using Me3SiCl/LiAlH4 under mild conditions. These findings are important for research groups investigating the efficacy of this drug and analogues in academia and industry.
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29
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Targeting MmpL3 for anti-tuberculosis drug development. Biochem Soc Trans 2021; 48:1463-1472. [PMID: 32662825 PMCID: PMC7458404 DOI: 10.1042/bst20190950] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 06/22/2020] [Accepted: 06/24/2020] [Indexed: 02/07/2023]
Abstract
The unique architecture of the mycobacterial cell envelope plays an important role in Mycobacterium tuberculosis (Mtb) pathogenesis. A critical protein in cell envelope biogenesis in mycobacteria, required for transport of precursors, trehalose monomycolates (TMMs), is the Mycobacterial membrane protein large 3 (MmpL3). Due to its central role in TMM transport, MmpL3 has been an attractive therapeutic target and a key target for several preclinical agents. In 2019, the first crystal structures of the MmpL3 transporter and its complexes with lipids and inhibitors were reported. These structures revealed several unique structural features of MmpL3 and provided invaluable information on the mechanism of TMM transport. This review aims to highlight the recent advances made in the function of MmpL3 and summarises structural findings. The overall goal is to provide a mechanistic perspective of MmpL3-mediated lipid transport and inhibition, and to highlight the prospects for potential antituberculosis therapies.
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30
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Klenotic PA, Moseng MA, Morgan CE, Yu EW. Structural and Functional Diversity of Resistance-Nodulation-Cell Division Transporters. Chem Rev 2021; 121:5378-5416. [PMID: 33211490 PMCID: PMC8119314 DOI: 10.1021/acs.chemrev.0c00621] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Multidrug resistant (MDR) bacteria are a global threat with many common infections becoming increasingly difficult to eliminate. While significant effort has gone into the development of potent biocides, the effectiveness of many first-line antibiotics has been diminished due to adaptive resistance mechanisms. Bacterial membrane proteins belonging to the resistance-nodulation-cell division (RND) superfamily play significant roles in mediating bacterial resistance to antimicrobials. They participate in multidrug efflux and cell wall biogenesis to transform bacterial pathogens into "superbugs" that are resistant even to last resort antibiotics. In this review, we summarize the RND superfamily of efflux transporters with a primary focus on the assembly and function of the inner membrane pumps. These pumps are critical for extrusion of antibiotics from the cell as well as the transport of lipid moieties to the outer membrane to establish membrane rigidity and stability. We analyze recently solved structures of bacterial inner membrane efflux pumps as to how they bind and transport their substrates. Our cumulative data indicate that these RND membrane proteins are able to utilize different oligomerization states to achieve particular activities, including forming MDR pumps and cell wall remodeling machineries, to ensure bacterial survival. This mechanistic insight, combined with simulated docking techniques, allows for the design and optimization of new efflux pump inhibitors to more effectively treat infections that today are difficult or impossible to cure.
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Affiliation(s)
- Philip A. Klenotic
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Mitchell A. Moseng
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Christopher E. Morgan
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
| | - Edward W. Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland OH 44106, USA
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31
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Alav I, Kobylka J, Kuth MS, Pos KM, Picard M, Blair JMA, Bavro VN. Structure, Assembly, and Function of Tripartite Efflux and Type 1 Secretion Systems in Gram-Negative Bacteria. Chem Rev 2021; 121:5479-5596. [PMID: 33909410 PMCID: PMC8277102 DOI: 10.1021/acs.chemrev.1c00055] [Citation(s) in RCA: 99] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/11/2022]
Abstract
Tripartite efflux pumps and the related type 1 secretion systems (T1SSs) in Gram-negative organisms are diverse in function, energization, and structural organization. They form continuous conduits spanning both the inner and the outer membrane and are composed of three principal components-the energized inner membrane transporters (belonging to ABC, RND, and MFS families), the outer membrane factor channel-like proteins, and linking the two, the periplasmic adaptor proteins (PAPs), also known as the membrane fusion proteins (MFPs). In this review we summarize the recent advances in understanding of structural biology, function, and regulation of these systems, highlighting the previously undescribed role of PAPs in providing a common architectural scaffold across diverse families of transporters. Despite being built from a limited number of basic structural domains, these complexes present a staggering variety of architectures. While key insights have been derived from the RND transporter systems, a closer inspection of the operation and structural organization of different tripartite systems reveals unexpected analogies between them, including those formed around MFS- and ATP-driven transporters, suggesting that they operate around basic common principles. Based on that we are proposing a new integrated model of PAP-mediated communication within the conformational cycling of tripartite systems, which could be expanded to other types of assemblies.
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Affiliation(s)
- Ilyas Alav
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Jessica Kobylka
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Miriam S. Kuth
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Klaas M. Pos
- Institute
of Biochemistry, Biocenter, Goethe Universität
Frankfurt, Max-von-Laue-Straße 9, D-60438 Frankfurt, Germany
| | - Martin Picard
- Laboratoire
de Biologie Physico-Chimique des Protéines Membranaires, CNRS
UMR 7099, Université de Paris, 75005 Paris, France
- Fondation
Edmond de Rothschild pour le développement de la recherche
Scientifique, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Jessica M. A. Blair
- Institute
of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Vassiliy N. Bavro
- School
of Life Sciences, University of Essex, Colchester, CO4 3SQ United Kingdom
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Jackson M, Stevens CM, Zhang L, Zgurskaya HI, Niederweis M. Transporters Involved in the Biogenesis and Functionalization of the Mycobacterial Cell Envelope. Chem Rev 2021; 121:5124-5157. [PMID: 33170669 PMCID: PMC8107195 DOI: 10.1021/acs.chemrev.0c00869] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The biology of mycobacteria is dominated by a complex cell envelope of unique composition and structure and of exceptionally low permeability. This cell envelope is the basis of many of the pathogenic features of mycobacteria and the site of susceptibility and resistance to many antibiotics and host defense mechanisms. This review is focused on the transporters that assemble and functionalize this complex structure. It highlights both the progress and the limits of our understanding of how (lipo)polysaccharides, (glyco)lipids, and other bacterial secretion products are translocated across the different layers of the cell envelope to their final extra-cytoplasmic location. It further describes some of the unique strategies evolved by mycobacteria to import nutrients and other products through this highly impermeable barrier.
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Affiliation(s)
- Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523-1682, USA
| | - Casey M. Stevens
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
| | - Helen I. Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK 73019, USA
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
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Zgurskaya HI, Walker JK, Parks JM, Rybenkov VV. Multidrug Efflux Pumps and the Two-Faced Janus of Substrates and Inhibitors. Acc Chem Res 2021; 54:930-939. [PMID: 33539084 PMCID: PMC8208102 DOI: 10.1021/acs.accounts.0c00843] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antibiotics are miracle drugs that can cure infectious bacterial diseases. However, their utility is challenged by antibiotic-resistant bacteria emerging in clinics and straining modern medicine and our ways of life. Certain bacteria such as Gram-negative (Gram(-)) and Mycobacteriales species are intrinsically resistant to most clinical antibiotics and can further gain multidrug resistance through mutations and plasmid acquisition. These species stand out by the presence of an additional external lipidic membrane, the outer membrane (OM), that is composed of unique glycolipids. Although formidable, the OM is a passive permeability barrier that can reduce penetration of antibiotics but cannot affect intracellular steady-state concentrations of drugs. The two-membrane envelopes are further reinforced by active efflux transporters that expel antibiotics from cells against their concentration gradients. The major mechanism of antibiotic resistance in Gram(-) pathogens is the active efflux of drugs, which acts synergistically with the low permeability barrier of the OM and other mutational and plasmid-borne mechanisms of antibiotic resistance.The synergy between active efflux and slow uptake offers Gram(-) bacteria an impressive degree of protection from potentially harmful chemicals, but it is also their Achilles heel. Kinetic studies have revealed that even small changes in the efficiency of either of the two factors can have dramatic effects on drug penetration into the cell. In line with these expectations, two major approaches to overcome this antibiotic resistance mechanism are currently being explored: (1) facilitation of antibiotic penetration across the outer membranes and (2) avoidance and inhibition of clinically relevant multidrug efflux pumps. Herein we summarize the progress in the latter approach with a focus on efflux pumps from the resistance-nodulation-division (RND) superfamily. The ability to export various substrates across the OM at the expense of the proton-motive force acting on the inner membrane and the engagement of accessory proteins for their functions are the major mechanistic advantages of these pumps. Both the RND transporters and their accessory proteins are being targeted in the discovery of efflux pump inhibitors, which in combination with antibiotics can potentiate antibacterial activities. We discuss intriguing relationships between substrates and inhibitors of efflux pumps, as these two types of ligands face similar barriers and binding sites in the transporters and accessory proteins and both types of activities often occur with the same chemical scaffold. Several distinct chemical classes of efflux inhibitors have been discovered that are as structurally diverse as the substrates of efflux pumps. Recent mechanistic insights, both empirical and computational, have led to the identification of features that distinguish OM permeators and efflux pump avoiders as well as efflux inhibitors from substrates. These findings suggest a path forward for optimizing the OM permeation and efflux-inhibitory activities in antibiotics and other chemically diverse compounds.
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Affiliation(s)
- Helen I Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - John K Walker
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Jerry M Parks
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Valentin V Rybenkov
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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Grover S, Engelhart CA, Pérez-Herrán E, Li W, Abrahams KA, Papavinasasundaram K, Bean JM, Sassetti CM, Mendoza-Losana A, Besra GS, Jackson M, Schnappinger D. Two-Way Regulation of MmpL3 Expression Identifies and Validates Inhibitors of MmpL3 Function in Mycobacterium tuberculosis. ACS Infect Dis 2021; 7:141-152. [PMID: 33319550 PMCID: PMC7802072 DOI: 10.1021/acsinfecdis.0c00675] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
![]()
MmpL3,
an essential mycolate transporter in the inner membrane
of Mycobacterium tuberculosis (Mtb), has been identified as a target of multiple, chemically diverse
antitubercular drugs. However, several of these molecules seem to
have secondary targets and inhibit bacterial growth by more than one
mechanism. Here, we describe a cell-based assay that utilizes two-way
regulation of MmpL3 expression to readily identify MmpL3-specific
inhibitors. We successfully used this assay to identify a novel guanidine-based
MmpL3 inhibitor from a library of 220 compounds that inhibit growth
of Mtb by largely unknown mechanisms. We furthermore
identified inhibitors of cytochrome bc1-aa3 oxidase as one class of off-target hits in whole-cell screens for
MmpL3 inhibitors and report a novel sulfanylacetamide as a potential
QcrB inhibitor.
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Affiliation(s)
- Shipra Grover
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York 10065, United States
| | - Curtis A. Engelhart
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York 10065, United States
| | - Esther Pérez-Herrán
- TB Research Unit, Global Health R&D, GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, Madrid 28760, Spain
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Katherine A. Abrahams
- Institute of Microbiology and Infection, School of Biological Sciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Kadamba Papavinasasundaram
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - James M. Bean
- Sloan Kettering Institute, New York, New York 10065, United States
| | - Christopher M. Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - Alfonso Mendoza-Losana
- TB Research Unit, Global Health R&D, GlaxoSmithKline, Severo Ochoa 2, Tres Cantos, Madrid 28760, Spain
| | - Gurdyal S. Besra
- Institute of Microbiology and Infection, School of Biological Sciences, University of Birmingham, Birmingham B15 2TT, U.K
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Dirk Schnappinger
- Department of Microbiology and Immunology, Weill Cornell Medicine, New York, New York 10065, United States
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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: 76] [Impact Index Per Article: 19.0] [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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Abstract
Mycobacterium tuberculosis is a major global human pathogen, and new drugs and new drug targets are urgently required. Cell wall biosynthesis is a major target of current tuberculosis drugs and of new agents under development. Several new classes of molecules appear to have the same target, MmpL3, which is involved in the export and synthesis of the mycobacterial cell wall. However, there is still debate over whether MmpL3 is the primary or only target for these classes. We wanted to confirm the mechanism of resistance for one series. We identified mutations in MmpL3 which led to resistance to the spiral amine series. High-level resistance to these compounds and two other series was conferred by multiple mutations in the same protein (MmpL3). These mutations did not reduce growth rate in culture. These results support the hypothesis that MmpL3 is the primary mechanism of resistance and likely target for these pharmacophores. The Mycobacterium tuberculosis protein MmpL3 performs an essential role in cell wall synthesis, since it effects the transport of trehalose monomycolates across the inner membrane. Numerous structurally diverse pharmacophores have been identified as inhibitors of MmpL3 largely based on the identification of resistant isolates with mutations in MmpL3. For some compounds, it is possible there are different primary or secondary targets. Here, we have investigated resistance to the spiral amine class of compounds. Isolation and sequencing of resistant mutants demonstrated that all had mutations in MmpL3. We hypothesized that if additional targets of this pharmacophore existed, then successive rounds to generate resistant isolates might reveal mutations in other loci. Since compounds were still active against resistant isolates, albeit with reduced potency, we isolated resistant mutants in this background at higher concentrations. After a second round of isolation with the spiral amine, we found additional mutations in MmpL3. To increase our chance of finding alternative targets, we ran a third round of isolation using a different molecule scaffold (AU1235, an adamantyl urea). Surprisingly, we obtained further mutations in MmpL3. Multiple mutations in MmpL3 increased the level and spectrum of resistance to different pharmacophores but did not incur a fitness cost in vitro. These results support the hypothesis that MmpL3 is the primary mechanism of resistance and likely target for these pharmacophores. IMPORTANCEMycobacterium tuberculosis is a major global human pathogen, and new drugs and new drug targets are urgently required. Cell wall biosynthesis is a major target of current tuberculosis drugs and of new agents under development. Several new classes of molecules appear to have the same target, MmpL3, which is involved in the export and synthesis of the mycobacterial cell wall. However, there is still debate over whether MmpL3 is the primary or only target for these classes. We wanted to confirm the mechanism of resistance for one series. We identified mutations in MmpL3 which led to resistance to the spiral amine series. High-level resistance to these compounds and two other series was conferred by multiple mutations in the same protein (MmpL3). These mutations did not reduce growth rate in culture. These results support the hypothesis that MmpL3 is the primary mechanism of resistance and likely target for these pharmacophores.
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Li M, Gašparovič H, Weng X, Chen S, Korduláková J, Jessen-Trefzer C. The Two-Component Locus MSMEG_0244/0246 Together With MSMEG_0243 Affects Biofilm Assembly in M. smegmatis Correlating With Changes in Phosphatidylinositol Mannosides Acylation. Front Microbiol 2020; 11:570606. [PMID: 33013801 PMCID: PMC7516205 DOI: 10.3389/fmicb.2020.570606] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/24/2020] [Indexed: 12/30/2022] Open
Abstract
Ferric and ferrous iron is an essential transition metal for growth of many bacterial species including mycobacteria. The genomic region msmeg_0234 to msmeg_0252 from Mycobacterium smegmatis is putatively involved in iron/heme metabolism. We investigate the genes encoding the presumed two component system MSMEG_0244/MSMEG_0246, the neighboring gene msmeg_0243 and their involvement in this process. We show that purified MSMEG_0243 indeed is a heme binding protein. Deletion of msmeg_0243/msmeg_0244/msmeg_0246 in Mycobacterium smegmatis leads to a defect in biofilm formation and colony growth on solid agar, however, this phenotype is independent of the supplied iron source. Further, analysis of the corresponding mutant and its lipids reveals that changes in morphology and biofilm formation correlate with altered acylation patterns of phosphatidylinositol mannosides (PIMs). We provide the first evidence that msmeg_0244/msmeg_0246 work in concert in cellular lipid homeostasis, especially in the maintenance of PIMs, with the heme-binding protein MSMEG_0243 as potential partner.
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Affiliation(s)
- Miaomaio Li
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Henrich Gašparovič
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Xing Weng
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Si Chen
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
| | - Jana Korduláková
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Bratislava, Slovakia
| | - Claudia Jessen-Trefzer
- Department of Pharmaceutical Biology and Biotechnology, University of Freiburg, Freiburg, Germany
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Sethiya JP, Sowards MA, Jackson M, North EJ. MmpL3 Inhibition: A New Approach to Treat Nontuberculous Mycobacterial Infections. Int J Mol Sci 2020; 21:E6202. [PMID: 32867307 PMCID: PMC7503588 DOI: 10.3390/ijms21176202] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/20/2020] [Accepted: 08/20/2020] [Indexed: 12/11/2022] Open
Abstract
Outside of Mycobacterium tuberculosis and Mycobacterium leprae, nontuberculous mycobacteria (NTM) are environmental mycobacteria (>190 species) and are classified as slow- or rapid-growing mycobacteria. Infections caused by NTM show an increased incidence in immunocompromised patients and patients with underlying structural lung disease. The true global prevalence of NTM infections remains unknown because many countries do not require mandatory reporting of the infection. This is coupled with a challenging diagnosis and identification of the species. Current therapies for treatment of NTM infections require multidrug regimens for a minimum of 18 months and are associated with serious adverse reactions, infection relapse, and high reinfection rates, necessitating discovery of novel antimycobacterial agents. Robust drug discovery processes have discovered inhibitors targeting mycobacterial membrane protein large 3 (MmpL3), a protein responsible for translocating mycolic acids from the inner membrane to periplasm in the biosynthesis of the mycobacterial cell membrane. This review focuses on promising new chemical scaffolds that inhibit MmpL3 function and represent interesting and promising putative drug candidates for the treatment of NTM infections. Additionally, agents (FS-1, SMARt-420, C10) that promote reversion of drug resistance are also reviewed.
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Affiliation(s)
- Jigar P. Sethiya
- Department of Pharmacy Sciences, School of Pharmacy & Health Professions, Creighton University, Omaha, NE 68178, USA; (J.P.S.); (M.A.S.)
| | - Melanie A. Sowards
- Department of Pharmacy Sciences, School of Pharmacy & Health Professions, Creighton University, Omaha, NE 68178, USA; (J.P.S.); (M.A.S.)
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA;
| | - Elton Jeffrey North
- Department of Pharmacy Sciences, School of Pharmacy & Health Professions, Creighton University, Omaha, NE 68178, USA; (J.P.S.); (M.A.S.)
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Alsayed SSR, Lun S, Luna G, Beh CC, Payne AD, Foster N, Bishai WR, Gunosewoyo H. Design, synthesis, and biological evaluation of novel arylcarboxamide derivatives as anti-tubercular agents. RSC Adv 2020; 10:7523-7540. [PMID: 33014349 PMCID: PMC7497412 DOI: 10.1039/c9ra10663d] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 02/10/2020] [Indexed: 12/19/2022] Open
Abstract
Our group has previously reported several indolecarboxamides exhibiting potent antitubercular activity. Herein, we rationally designed several arylcarboxamides based on our previously reported homology model and the recently published crystal structure of the mycobacterial membrane protein large 3 (MmpL3). Many analogues showed considerable anti-TB activity against drug-sensitive (DS) Mycobacterium tuberculosis (M. tb) strain. Naphthamide derivatives 13c and 13d were the most active compounds in our study (MIC: 6.55, 7.11 μM, respectively), showing comparable potency to the first line anti-tuberculosis (anti-TB) drug ethambutol (MIC: 4.89 μM). In addition to the naphthamide derivatives, we also identified the quinolone-2-carboxamides and 4-arylthiazole-2-carboxamides as potential MmpL3 inhibitors in which compounds 8i and 18b had MIC values of 9.97 and 9.82 μM, respectively. All four compounds retained their high activity against multidrug-resistant (MDR) and extensively drug-resistant (XDR) M. tb strains. It is worth noting that the two most active compounds 13c and 13d also exhibited the highest selective activity towards DS, MDR and XDR M. tb strains over mammalian cells [IC50 (Vero cells) ≥ 227 μM], indicating their potential lack of cytotoxicity. The four compounds were docked into the MmpL3 active site and were studied for their drug-likeness using Lipinski's rule of five. Synthesis and pharmacological evaluation of arylcarboxamide derivatives based on an antimycobacterial indole-2-carboxamide scaffold. The most active compounds demonstrated activities against MDR and XDR M. tb strains.![]()
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Affiliation(s)
- Shahinda S R Alsayed
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, Perth, WA 6102, Australia.
| | - Shichun Lun
- Center for Tuberculosis Research, Department of Medicine, Division of Infectious Disease, Johns Hopkins School of Medicine, 1550, Orleans Street, Baltimore, Maryland 21231-1044, USA.
| | - Giuseppe Luna
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, Perth, WA 6102, Australia.
| | - Chau Chun Beh
- 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
| | - Neil Foster
- Western Australia School of Mines: Minerals, Energy and Chemical Engineering, Curtin University, Bentley 6102, WA, Australia
| | - William R Bishai
- Center for Tuberculosis Research, Department of Medicine, Division of Infectious Disease, Johns Hopkins School of Medicine, 1550, Orleans Street, Baltimore, Maryland 21231-1044, USA. .,Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, Maryland 20815-6789, USA
| | - Hendra Gunosewoyo
- School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Bentley, Perth, WA 6102, Australia.
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Raynaud C, Daher W, Johansen MD, Roquet-Banères F, Blaise M, Onajole OK, Kozikowski AP, Herrmann JL, Dziadek J, Gobis K, Kremer L. Active Benzimidazole Derivatives Targeting the MmpL3 Transporter in Mycobacterium abscessus. ACS Infect Dis 2020; 6:324-337. [PMID: 31860799 DOI: 10.1021/acsinfecdis.9b00389] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The prevalence of pulmonary infections due to nontuberculous mycobacteria such as Mycobacterium abscessus has been increasing and surpassing tuberculosis (TB) in some industrialized countries. Because of intrinsic resistance to most antibiotics that drastically limits conventional chemotherapeutic treatment options, new anti-M. abscessus therapeutics are urgently needed against this emerging pathogen. Extensive screening of a library of benzimidazole derivatives that were previously shown to be active against Mycobacterium tuberculosis led to the identification of a lead compound exhibiting very potent in vitro activity against a wide panel of M. abscessus clinical strains. Designated EJMCh-6, this compound, a 2-(2-cyclohexylethyl)-5,6-dimethyl-1H-benzo[d]imidazole), also exerted very strong activity against intramacrophage-residing M. abscessus. Moreover, the treatment of infected zebrafish embryos with EJMCh-6 was correlated with significantly increased embryo survival and a decrease in the bacterial burden as compared to those for untreated fish. Insights into the mechanism of action were inferred from the generation of spontaneous benzimidazole-resistant strains and the identification of a large set of missense mutations in MmpL3, the mycolic acid transporter in mycobacteria. Overexpression of the mutated mmpL3 alleles in a susceptible M. abscessus strain was associated with high resistance levels to EJMCh-6 and to other known MmpL3 inhibitors. Mapping the mutations conferring resistance on an MmpL3 three-dimensional homology model defined a potential EJMCh-6-binding cavity. These data emphasize a yet unexploited chemical structure class against M. abscessus with promising translational development for the treatment of M. abscessus lung diseases.
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Affiliation(s)
- Clément Raynaud
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Wassim Daher
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Matt D. Johansen
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Françoise Roquet-Banères
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Mickael Blaise
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Oluseye K. Onajole
- Department of Biological, Physical and Health Sciences, Roosevelt University, 425 S. Wabash Avenue, Chicago, Illinois 60605, United States
| | - Alan P. Kozikowski
- StarWise Therapeutics LLC, 2020 N. Lincoln Park West, Chicago, Illinois 60614, United States
| | - Jean-Louis Herrmann
- 2I, UVSQ, INSERM UMR1173, Université Paris-Saclay, 2 avenue de la Source de la Bièvre, 78180 Montigny-Le-Bretonneux, France
- APHP, GHU-Paris Saclay, Hôpital Raymond Poincaré, Garches, France
| | - Jaroslaw Dziadek
- Institute for Medical Biology, Polish Academy of Sciences, Lodowa 106, Łódź 93-232, Poland
| | - Katarzyna Gobis
- Department of Organic Chemistry, Medical University of Gdansk, 107 Gen. Hallera Avenue, 80-416 Gdansk, Poland
| | - Laurent Kremer
- Centre National de la Recherche Scientifique UMR 9004, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
- INSERM, IRIM, 34293 Montpellier, France
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41
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Zhang L, Hendrickson RC, Meikle V, Lefkowitz EJ, Ioerger TR, Niederweis M. Comprehensive analysis of iron utilization by Mycobacterium tuberculosis. PLoS Pathog 2020; 16:e1008337. [PMID: 32069330 PMCID: PMC7058343 DOI: 10.1371/journal.ppat.1008337] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/05/2020] [Accepted: 01/20/2020] [Indexed: 12/16/2022] Open
Abstract
Iron is essential for nearly all bacterial pathogens, including Mycobacterium tuberculosis (Mtb), but is severely limited in the human host. To meet its iron needs, Mtb secretes siderophores, small molecules with high affinity for iron, and takes up iron-loaded mycobactins (MBT) and carboxymycobactins (cMBT), from the environment. Mtb is also capable of utilizing heme and hemoglobin which contain more than 70% of the iron in the human body. However, many components of these iron acquisition pathways are still unknown. In this study, a high-density transposon mutagenesis coupled with deep sequencing (TnSeq) showed that Mtb exhibits nearly opposite requirements for 165 genes in the presence of heme and hemoglobin versus MBT and cMBT as iron sources. The ESX-3 secretion system was assessed as essential for siderophore-mediated iron uptake and, surprisingly, also for heme utilization by Mtb. Predictions derived from the TnSeq analysis were validated by growth experiments with isogenic Mtb mutants. These results showed that (i) the efflux pump MmpL5 plays a dominant role in siderophore secretion, (ii) the Rv2047c protein is essential for growth of Mtb in the presence of mycobactin, and (iii) the transcriptional repressor Zur is required for heme utilization by Mtb. The novel genetic determinants of iron utilization revealed in this study will stimulate further experiments in this important area of Mtb physiology.
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Affiliation(s)
- Lei Zhang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - R. Curtis Hendrickson
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Virginia Meikle
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Elliot J. Lefkowitz
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Thomas R. Ioerger
- Department of Computer Science and Engineering, Texas A&M University, College Station, Texas, United States of America
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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Promiscuous Targets for Antitubercular Drug Discovery: The Paradigm of DprE1 and MmpL3. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10020623] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The development and spread of Mycobacterium tuberculosis multi-drug resistant strains still represent a great global health threat, leading to an urgent need for novel anti-tuberculosis drugs. Indeed, in the last years, several efforts have been made in this direction, through a number of high-throughput screenings campaigns, which allowed for the identification of numerous hit compounds and novel targets. Interestingly, several independent screening assays identified the same proteins as the target of different compounds, and for this reason, they were named “promiscuous” targets. These proteins include DprE1, MmpL3, QcrB and Psk13, and are involved in the key pathway for M. tuberculosis survival, thus they should represent an Achilles’ heel which could be exploited for the development of novel effective drugs. Indeed, among the last molecules which entered clinical trials, four inhibit a promiscuous target. Within this review, the two most promising promiscuous targets, the oxidoreductase DprE1 involved in arabinogalactan synthesis and the mycolic acid transporter MmpL3 are discussed, along with the latest advancements in the development of novel inhibitors with anti-tubercular activity.
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43
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Zhang B, Li J, Yang X, Wu L, Zhang J, Yang Y, Zhao Y, Zhang L, Yang X, Yang X, Cheng X, Liu Z, Jiang B, Jiang H, Guddat LW, Yang H, Rao Z. Crystal Structures of Membrane Transporter MmpL3, an Anti-TB Drug Target. Cell 2019; 176:636-648.e13. [PMID: 30682372 DOI: 10.1016/j.cell.2019.01.003] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 10/22/2018] [Accepted: 12/31/2018] [Indexed: 01/01/2023]
Abstract
Despite intensive efforts to discover highly effective treatments to eradicate tuberculosis (TB), it remains as a major threat to global human health. For this reason, new TB drugs directed toward new targets are highly coveted. MmpLs (Mycobacterial membrane proteins Large), which play crucial roles in transporting lipids, polymers and immunomodulators and which also extrude therapeutic drugs, are among the most important therapeutic drug targets to emerge in recent times. Here, crystal structures of mycobacterial MmpL3 alone and in complex with four TB drug candidates, including SQ109 (in Phase 2b-3 clinical trials), are reported. MmpL3 consists of a periplasmic pore domain and a twelve-helix transmembrane domain. Two Asp-Tyr pairs centrally located in this domain appear to be key facilitators of proton-translocation. SQ109, AU1235, ICA38, and rimonabant bind inside the transmembrane region and disrupt these Asp-Tyr pairs. This structural data will greatly advance the development of MmpL3 inhibitors as new TB drugs.
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Affiliation(s)
- Bing Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Jun Li
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China.
| | - Xiaolin Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Lijie Wu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Jia Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Yang Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yao Zhao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Lu Zhang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300353, China
| | - Xiuna Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaobao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xi Cheng
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Zhijie Liu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Biao Jiang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Hualiang Jiang
- Drug Discovery and Design Center, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Luke W Guddat
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China.
| | - Zihe Rao
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, 200031, China; State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, 300353, China; National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China; Laboratory of Structural Biology, Tsinghua University, Beijing, 100084, China.
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Dal Molin M, Selchow P, Schäfle D, Tschumi A, Ryckmans T, Laage-Witt S, Sander P. Identification of novel scaffolds targeting Mycobacterium tuberculosis. J Mol Med (Berl) 2019; 97:1601-1613. [PMID: 31728550 DOI: 10.1007/s00109-019-01840-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 09/13/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
Abstract
Drug resistance in Mycobacterium tuberculosis is relentlessly progressing while only a handful of novel drug candidates are developed. Here we describe a GFP-based high-throughput screening of 386,496 diverse compounds to identify putative tuberculosis drug candidates. In an exploratory analysis of the model organism M. bovis BCG and M. smegmatis and the subsequent screening of the main library, we identified 6354 compounds with anti-mycobacterial activity. These hit compounds were predominantly selective for mycobacteria while dozens had activity in the low μM range. We tested toxicity against the human monocyte/macrophage cell line THP-1 and elaborated activity against M. tuberculosis growing in liquid broth, under unique conditions such as non-replicating persistence or inhibition of M. tuberculosis residing in macrophages. Finally, spontaneous compound-resistant M. tuberculosis mutants were selected and subsequently analyzed by whole genome sequencing. In addition to compounds targeting the well-described proteins Pks13 and MmpL3, we identified two novel scaffolds targeting the bifunctional guanosine pentaphosphate synthetase/ polyribonucleotide nucleotidyltransferase GpsI, or interacting with the aminopeptidase PepB, a probable pro-drug activator. KEY MESSAGES: A newly identified scaffold targets the bifunctional enzyme GpsI. The aminopeptidase PepB is interacting with a second novel scaffold. Phenotypic screenings regularly identify novel compounds targeting Pks13 and MmpL3.
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Affiliation(s)
- Michael Dal Molin
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006, Zürich, Switzerland
| | - Petra Selchow
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006, Zürich, Switzerland
| | - Daniel Schäfle
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006, Zürich, Switzerland
| | - Andreas Tschumi
- Roche Pharma Research and Early Development, Infectious Diseases, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070, Basel, Switzerland
| | - Thomas Ryckmans
- Roche Pharma Research and Early Development, Infectious Diseases, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070, Basel, Switzerland
| | - Stephan Laage-Witt
- Roche Pharma Research and Early Development, Infectious Diseases, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070, Basel, Switzerland
| | - Peter Sander
- Institut für Medizinische Mikrobiologie, Universität Zürich, 8006, Zürich, Switzerland. .,Nationales Zentrum für Mykobakterien, 8006, Zürich, Switzerland.
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Identification of New MmpL3 Inhibitors by Untargeted and Targeted Mutant Screens Defines MmpL3 Domains with Differential Resistance. Antimicrob Agents Chemother 2019; 63:AAC.00547-19. [PMID: 31405862 DOI: 10.1128/aac.00547-19] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/26/2019] [Indexed: 12/13/2022] Open
Abstract
The Mycobacterium tuberculosis mycolate flippase MmpL3 has been the proposed target for multiple inhibitors with diverse chemical scaffolds. This diversity in chemical scaffolds has made it difficult to predict compounds that inhibit MmpL3 without whole-genome sequencing of isolated resistant mutants. Here, we describe the identification of four new inhibitors that select for resistance mutations in mmpL3. Using these resistant mutants, we conducted a targeted whole-cell phenotypic screen of 163 novel M. tuberculosis growth inhibitors for differential growth inhibition of wild-type M. tuberculosis compared to the growth of a pool of 24 unique mmpL3 mutants. The screen successfully identified six additional putative MmpL3 inhibitors. The compounds were bactericidal both in vitro and against intracellular M. tuberculosis M. tuberculosis cells treated with these compounds were shown to accumulate trehalose monomycolates, have reduced levels of trehalose dimycolate, and displace an MmpL3-specific probe, supporting MmpL3 as the target. The inhibitors were mycobacterium specific, with several also showing activity against the nontuberculous mycobacterial species M. abscessus Cluster analysis of cross-resistance profiles generated by dose-response experiments for each combination of 13 MmpL3 inhibitors against each of the 24 mmpL3 mutants defined two clades of inhibitors and two clades of mmpL3 mutants. Pairwise combination studies of the inhibitors revealed interactions that were specific to the clades identified in the cross-resistance profiling. Additionally, modeling of resistance-conferring substitutions to the MmpL3 crystal structure revealed clade-specific localization of the residues to specific domains of MmpL3, with the clades showing differential resistance. Several compounds exhibited high solubility and stability in microsomes and low cytotoxicity in macrophages, supporting their further development. The combined study of multiple mutants and novel compounds provides new insights into structure-function interactions of MmpL3 and small-molecule inhibitors.
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1 H-Benzo[ d]Imidazole Derivatives Affect MmpL3 in Mycobacterium tuberculosis. Antimicrob Agents Chemother 2019; 63:AAC.00441-19. [PMID: 31332069 DOI: 10.1128/aac.00441-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/15/2019] [Indexed: 12/29/2022] Open
Abstract
1H-benzo[d]imidazole derivatives exhibit antitubercular activity in vitro at a nanomolar range of concentrations and are not toxic to human cells, but their mode of action remains unknown. Here, we showed that these compounds are active against intracellular Mycobacterium tuberculosis To identify their target, we selected drug-resistant M. tuberculosis mutants and then used whole-genome sequencing to unravel mutations in the essential mmpL3 gene, which encodes the integral membrane protein that catalyzes the export of trehalose monomycolate, a precursor of the mycobacterial outer membrane component trehalose dimycolate (TDM), as well as mycolic acids bound to arabinogalactan. The drug-resistant phenotype was also observed in the parental strain overexpressing the mmpL3 alleles carrying the mutations identified in the resistors. However, no cross-resistance was observed between 1H-benzo[d]imidazole derivatives and SQ109, another MmpL3 inhibitor, or other first-line antitubercular drugs. Metabolic labeling and quantitative thin-layer chromatography (TLC) analysis of radiolabeled lipids from M. tuberculosis cultures treated with the benzoimidazoles indicated an inhibition of trehalose dimycolate (TDM) synthesis, as well as reduced levels of mycolylated arabinogalactan, in agreement with the inhibition of MmpL3 activity. Overall, this study emphasizes the pronounced activity of 1H-benzo[d]imidazole derivatives in interfering with mycolic acid metabolism and their potential for therapeutic application in the fight against tuberculosis.
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Mitra A, Ko YH, Cingolani G, Niederweis M. Heme and hemoglobin utilization by Mycobacterium tuberculosis. Nat Commun 2019; 10:4260. [PMID: 31534126 PMCID: PMC6751184 DOI: 10.1038/s41467-019-12109-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 08/21/2019] [Indexed: 12/31/2022] Open
Abstract
Iron is essential for growth of Mycobacterium tuberculosis (Mtb), but most iron in the human body is stored in heme within hemoglobin. Here, we demonstrate that the substrate-binding protein DppA of the inner membrane Dpp transporter is required for heme and hemoglobin utilization by Mtb. The 1.27 Å crystal structure of DppA shows a tetrapeptide bound in the protein core and a large solvent-exposed crevice for heme binding. Mutation of arginine 179 in this cleft eliminates heme binding to DppA and prevents heme utilization by Mtb. The outer membrane proteins PPE36 and PPE62 are also required for heme and hemoglobin utilization, indicating that these pathways converge at the cell surface of Mtb. Albumin, the most abundant blood protein, binds heme specifically and bypasses the requirements for PPE36, PPE62 and Dpp. Thus, our study reveals albumin-dependent and -independent heme uptake pathways, highlighting the importance of iron acquisition from heme for Mtb.
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Affiliation(s)
- Avishek Mitra
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Ying-Hui Ko
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233S. 10th Street, Philadelphia, PA, 19107, USA
| | - Gino Cingolani
- Department of Biochemistry and Molecular Biology, Thomas Jefferson University, 233S. 10th Street, Philadelphia, PA, 19107, USA. .,Institute of Biomembranes and Bioenergetics, National Research Council, Via Amendola 165/A, 70126, Bari, Italy.
| | - Michael Niederweis
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA.
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Belardinelli JM, Stevens CM, Li W, Tan YZ, Jones V, Mancia F, Zgurskaya HI, Jackson M. The MmpL3 interactome reveals a complex crosstalk between cell envelope biosynthesis and cell elongation and division in mycobacteria. Sci Rep 2019; 9:10728. [PMID: 31341202 PMCID: PMC6656915 DOI: 10.1038/s41598-019-47159-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 07/08/2019] [Indexed: 01/19/2023] Open
Abstract
Integral membrane transporters of the Mycobacterial Membrane Protein Large (MmpL) family and their interactome play important roles in the synthesis and export of mycobacterial outer membrane lipids. Despite the current interest in the mycolic acid transporter, MmpL3, from the perspective of drug discovery, the nature and biological significance of its interactome remain largely unknown. We here report on a genome-wide screening by two-hybrid system for MmpL3 binding partners. While a surprisingly low number of proteins involved in mycolic acid biosynthesis was found to interact with MmpL3, numerous enzymes and transporters participating in the biogenesis of peptidoglycan, arabinogalactan and lipoglycans, and the cell division regulatory protein, CrgA, were identified among the hits. Surface plasmon resonance and co-immunoprecipitation independently confirmed physical interactions for three proteins in vitro and/or in vivo. Results are in line with the focal localization of MmpL3 at the poles and septum of actively-growing bacilli where the synthesis of all major constituents of the cell wall core are known to occur, and are further suggestive of a role for MmpL3 in the coordination of new cell wall deposition during cell septation and elongation. This novel aspect of the physiology of MmpL3 may contribute to the extreme vulnerability and high therapeutic potential of this transporter.
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Affiliation(s)
- Juan Manuel Belardinelli
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Casey M Stevens
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Yong Zi Tan
- Department of Physiology and Cellular Biophysics, Columbia University, 1150 St. Nicholas Avenue, New York, NY, 10032, USA
| | - Victoria Jones
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA
| | - Filippo Mancia
- Department of Physiology and Cellular Biophysics, Columbia University, 1150 St. Nicholas Avenue, New York, NY, 10032, USA
| | - Helen I Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, 101 Stephenson Parkway, Norman, OK, 73019, USA
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, 80523-1682, USA.
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Bahuguna A, Rawat DS. An overview of new antitubercular drugs, drug candidates, and their targets. Med Res Rev 2019; 40:263-292. [PMID: 31254295 DOI: 10.1002/med.21602] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 12/15/2022]
Abstract
The causative agent of tuberculosis (TB), Mycobacterium tuberculosis and more recently totally drug-resistant strains of M. tuberculosis, display unique mechanisms to survive in the host. A four-drug treatment regimen was introduced 40 years ago but the emergence of multidrug-resistance and more recently TDR necessitates the identification of new targets and drugs for the cure of M. tuberculosis infection. The current efforts in the drug development process are insufficient to completely eradicate the TB epidemic. For almost five decades the TB drug development process remained stagnant. The last 10 years have made sudden progress giving some new and highly promising drugs including bedaquiline, delamanid, and pretomanid. Many of the candidates are repurposed compounds, which were developed to treat other infections but later, exhibited anti-TB properties also. Each class of drug has a specific target and a definite mode of action. These targets are either involved in cell wall biosynthesis, protein synthesis, DNA/RNA synthesis, or metabolism. This review discusses recent progress in the discovery of newly developed and Food and Drug Administration approved drugs as well as repurposed drugs, their targets, mode of action, drug-target interactions, and their structure-activity relationship.
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Affiliation(s)
| | - Diwan S Rawat
- Department of Chemistry, University of Delhi, Delhi, India
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50
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Li W, Stevens CM, Pandya AN, Darzynkiewicz Z, Bhattarai P, Tong W, Gonzalez-Juarrero M, North EJ, Zgurskaya HI, Jackson M. Direct Inhibition of MmpL3 by Novel Antitubercular Compounds. ACS Infect Dis 2019; 5:1001-1012. [PMID: 30882198 PMCID: PMC6580365 DOI: 10.1021/acsinfecdis.9b00048] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
MmpL3, an essential transporter involved in the export of mycolic acids, is the proposed target of a number of antimycobacterial inhibitors under development. Whether MmpL3 serves as the direct target of these compounds, however, has been called into question after the discovery that some of them dissipated the proton motive force from which MmpL transporters derive their energy. Using a combination of in vitro and whole-cell-based approaches, we here provide evidence that five structurally distinct MmpL3 inhibitor series, three of which impact proton motive force in Mycobacterium tuberculosis, directly interact with MmpL3. Medium- to high-throughput assays based on these approaches were developed to facilitate the future screening and optimization of MmpL3 inhibitors. The promiscuity of MmpL3 as a drug target and the mechanisms through which missense mutations located in a transmembrane region of this transporter may confer cross-resistance to a variety of chemical scaffolds are discussed in light of the exquisite vulnerability of MmpL3, its apparent mechanisms of interaction with inhibitors, and evidence of conformational changes induced both by the inhibitors and one of the most commonly identified resistance mutations in MmpL3.
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Affiliation(s)
- Wei Li
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Casey M. Stevens
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Amitkumar N. Pandya
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Zbigniew Darzynkiewicz
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Pankaj Bhattarai
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Weiwei Tong
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
| | - E. Jeffrey North
- School of Pharmacy & Health Professions, Department of Pharmacy Sciences, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Helen I. Zgurskaya
- Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Mary Jackson
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, Colorado 80523, United States
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