1
|
Singh P, Kumar A, Sharma P, Chugh S, Kumar A, Sharma N, Gupta S, Singh M, Kidwai S, Sankar J, Taneja N, Kumar Y, Dhiman R, Mahajan D, Singh R. Identification and optimization of pyridine carboxamide-based scaffold as a drug lead for Mycobacterium tuberculosis. Antimicrob Agents Chemother 2024; 68:e0076623. [PMID: 38193667 PMCID: PMC10848774 DOI: 10.1128/aac.00766-23] [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: 06/09/2023] [Accepted: 11/10/2023] [Indexed: 01/10/2024] Open
Abstract
New drugs with novel mechanisms of action are urgently needed to tackle the issue of drug-resistant tuberculosis. Here, we have performed phenotypic screening using the Pathogen Box library obtained from the Medicines for Malaria Venture against Mycobacterium tuberculosis in vitro. We have identified a pyridine carboxamide derivative, MMV687254, as a promising hit. This molecule is specifically active against M. tuberculosis and Mycobacterium bovis Bacillus Calmette-Guérin (M. bovis BCG) but inactive against Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa, and Escherichia coli pathogens. We demonstrate that MMV687254 inhibits M. tuberculosis growth in liquid cultures in a bacteriostatic manner. Surprisingly, MMV687254 was as active as isoniazid in macrophages and inhibited M. tuberculosis growth in a bactericidal manner. Mechanistic studies revealed that MMV687254 is a prodrug and that its anti-mycobacterial activity requires AmiC-dependent hydrolysis. We further demonstrate that MMV687254 inhibits M. tuberculosis growth in macrophages by inducing autophagy. In the present study, we have also carried out a detailed structure-activity relationship study and identified a promising novel lead candidate. The identified novel series of compounds also showed activity against drug-resistant M. bovis BCG and M. tuberculosis clinical strains. Finally, we demonstrate that in contrast to MMV687254, the lead molecule was able to inhibit M. tuberculosis growth in a chronic mouse model of infection. Taken together, we have identified a novel lead molecule with a dual mechanism of action that can be further optimized to design more potent anti-tubercular agents.
Collapse
Affiliation(s)
- Padam Singh
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Arun Kumar
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Pankaj Sharma
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Saurabh Chugh
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Ashish Kumar
- Department of Life Science, Laboratory of Mycobacterial Immunology, National Institute of Technology, Rourkela, India
| | - Nidhi Sharma
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Sonu Gupta
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Manisha Singh
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Saqib Kidwai
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Jishnu Sankar
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Neha Taneja
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Yashwant Kumar
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Rohan Dhiman
- Department of Life Science, Laboratory of Mycobacterial Immunology, National Institute of Technology, Rourkela, India
| | - Dinesh Mahajan
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| | - Ramandeep Singh
- Translational Health Sciences and Technology Institute, NCR Biotech Science Cluster, Faridabad, Haryana, India
| |
Collapse
|
2
|
Adhikrao PA, Motiram GM, Kumar G. Tackling Nontuberculous Mycobacteria by Repurposable Drugs and Potential Leads from Natural Products. Curr Top Med Chem 2024; 24:1291-1326. [PMID: 38288807 DOI: 10.2174/0115680266276938240108060247] [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: 08/31/2023] [Revised: 12/12/2023] [Accepted: 12/19/2023] [Indexed: 07/25/2024]
Abstract
Nontuberculous Mycobacteria (NTM) refer to bacteria other than all Mycobacterium species that do not cause tuberculosis or leprosy, excluding the species of the Mycobacterium tuberculosis complex, M. leprae and M. lepromatosis. NTM are ubiquitous and present in soils and natural waters. NTM can survive in a wide range of environmental conditions. The direct inoculum of the NTM from water or other materials is most likely a source of infections. NTMs are responsible for several illnesses, including pulmonary alveolar proteinosis, cystic fibrosis, bronchiectasis, chronic obstructive pneumoconiosis, and pulmonary disease. Recent reports suggest that NTM species have become insensitive to sterilizing agents, antiseptics, and disinfectants. The efficacy of existing anti-NTM regimens is diminishing and has been compromised due to drug resistance. New and recurring cases of multidrug-resistant NTM strains are increasing. Thus, there is an urgent need for ant-NTM regimens with novel modes of action. This review sheds light on the mode of antimicrobial resistance in the NTM species. Then, we discussed the repurposable drugs (antibiotics) that have shown new indications (activity against NTM strains) that could be developed for treating NTM infections. Also, we have summarised recently identified natural leads acting against NTM, which have the potential for treating NTM-associated infections.
Collapse
Affiliation(s)
- Patil Amruta Adhikrao
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Balanagar, 500037, India
| | - Gudle Mayuri Motiram
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Balanagar, 500037, India
| | - Gautam Kumar
- Department of Natural Products, Chemical Sciences, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad, Balanagar, 500037, India
| |
Collapse
|
3
|
Ray B, Roy KK. Deciphering insights into the binding mechanism and plasticity of Telacebec with M. tuberculosis cytochrome bcc-aa3 supercomplex through an unbiased molecular dynamics simulation, free-energy analysis, and DFT study. J Biomol Struct Dyn 2023:1-14. [PMID: 38111165 DOI: 10.1080/07391102.2023.2294833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 12/02/2023] [Indexed: 12/20/2023]
Abstract
The cytochrome bcc-aa3 supercomplex, a key component in the electron transport chain pathway involved in bacterial energy production and homeostasis, is a clinically validated target for tuberculosis (TB), leading to Telacebec (Q203). Telacebec is a potent candidate drug under Phase II clinical development for the treatment of drug-sensitive and drug-resistant TB. Recently, the cryo-electron microscopy structure of this supercomplex from Mycobacterium tuberculosis (Mtb) complexed with Q203 was resolved at 6.9 Å resolution (PDB ID: 7E1W). To understand the binding site (QP site) flexibility and Q203's stability at the QP site of the Mtb cytochrome bcc complex, we conducted molecular dynamics (MD) simulation and free energy analysis on this complex in an explicit hydrated lipid bilayer environment for 500 ns. Through this study, the persistence of a range of direct and indirect interactions was observed over the course of the simulation. The significance of the interactions with His375, Tyr161, Ala178, Ala179, Ile183, His355, Leu356, and Thr313 is underlined. Electrostatic energy was the primary source of the net binding free energy, regardless of the important interacting residues. The overall binding free energy for Q203 was -112.84 ± 7.73 kcal/mol, of which the electrostatic and lipophilic energy contributions were -116.31 ± 1.14 and -21.32 ± 2.35 kcal/mol, respectively. Meanwhile, DFT calculations were utilized to elucidate Q203's molecular properties. Overall, this study deciphers key insights into the cytochrome bcc-aa3 supercomplex with Q203 on the ground of molecular mechanics and quantum mechanics that may facilitate structure-based drug design and optimization for the discovery of the next-generation antitubercular drug(s).Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Bedabrata Ray
- Department of Pharmaceutical Sciences, School of Health Sciences and Technology, UPES, Dehradun, Uttarakhand, India
| | - Kuldeep K Roy
- Department of Pharmaceutical Sciences, School of Health Sciences and Technology, UPES, Dehradun, Uttarakhand, India
| |
Collapse
|
4
|
Capela R, Félix R, Clariano M, Nunes D, Perry MDJ, Lopes F. Target Identification in Anti-Tuberculosis Drug Discovery. Int J Mol Sci 2023; 24:10482. [PMID: 37445660 DOI: 10.3390/ijms241310482] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/17/2023] [Accepted: 06/20/2023] [Indexed: 07/15/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) is the etiological agent of tuberculosis (TB), a disease that, although preventable and curable, remains a global epidemic due to the emergence of resistance and a latent form responsible for a long period of treatment. Drug discovery in TB is a challenging task due to the heterogeneity of the disease, the emergence of resistance, and uncomplete knowledge of the pathophysiology of the disease. The limited permeability of the cell wall and the presence of multiple efflux pumps remain a major barrier to achieve effective intracellular drug accumulation. While the complete genome sequence of Mtb has been determined and several potential protein targets have been validated, the lack of adequate models for in vitro and in vivo studies is a limiting factor in TB drug discovery programs. In current therapeutic regimens, less than 0.5% of bacterial proteins are targeted during the biosynthesis of the cell wall and the energetic metabolism of two of the most important processes exploited for TB chemotherapeutics. This review provides an overview on the current challenges in TB drug discovery and emerging Mtb druggable proteins, and explains how chemical probes for protein profiling enabled the identification of new targets and biomarkers, paving the way to disruptive therapeutic regimens and diagnostic tools.
Collapse
Affiliation(s)
- Rita Capela
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Rita Félix
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Marta Clariano
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Diogo Nunes
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Maria de Jesus Perry
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| | - Francisca Lopes
- Instituto de Investigação do Medicamento (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal
| |
Collapse
|
5
|
Kelam LM, Wani MA, Dhaked DK. An update on ATP synthase inhibitors: A unique target for drug development in M. tuberculosis. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 180-181:87-104. [PMID: 37105260 DOI: 10.1016/j.pbiomolbio.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 04/29/2023]
Abstract
ATP synthase is a key protein in the oxidative phosphorylation process, as it aids in the effective production of ATP (Adenosine triphosphate) in all life's of kingdoms. ATP synthases have distinctive properties that contribute to efficient ATP synthesis. The ATP synthase of mycobacterium is of special relevance since it has been identified as a target for potential anti-TB molecules, especially Bedaquiline (BDQ). Better knowledge of how mycobacterial ATP synthase functions and its peculiar characteristics will aid in our understanding of bacterial energy metabolism adaptations. Furthermore, identifying and understanding the important distinctions between human ATP synthase and bacterial ATP synthase may provide insight into the design and development of inhibitors that target specific ATP synthase. In recent years, many potential candidates targeting the ATP synthase of mycobacterium have been developed. In this review, we discuss the druggable targets of the Electron transport chain (ETC) and recently identified potent inhibitors (including clinical molecules) from 2015 to 2022 of diverse classes that target ATP synthase of M. tuberculosis.
Collapse
Affiliation(s)
- Lakshmi Mounika Kelam
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India
| | - Mushtaq Ahmad Wani
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India
| | - Devendra K Dhaked
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, 700054, West Bengal, India.
| |
Collapse
|
6
|
Imran M, Alotaibi NM, Thabet HK, Alruwaili JA, Asdaq SMB, Eltaib L, Alshehri A, Alsaiari AA, Almehmadi M, Alshammari ABH, Alshammari AM. QcrB inhibition as a potential approach for the treatment of tuberculosis: A review of recent developments, patents, and future directions. J Infect Public Health 2023; 16:928-937. [PMID: 37086552 DOI: 10.1016/j.jiph.2023.04.011] [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: 01/29/2023] [Revised: 03/28/2023] [Accepted: 04/11/2023] [Indexed: 04/24/2023] Open
Abstract
The unmet medical need for drug-resistant tuberculosis (DRTB) is a significant concern. Accordingly, identifying new drug targets for tuberculosis (TB) treatment and developing new therapies based on these drug targets is one of the strategies to tackle DRTB. QcrB is an innovative drug target to create treatments for DRTB. This article highlights QcrB inhibitors and their therapeutic compositions for treating TB. The literature for this article was gathered from PubMed and free patent databases utilizing different keywords related to QcrB inhibitor-based inventions. The data was collected from the conceptualization of telacebec (2010) QcrB to December 2022. A little interesting and encouraging research has been performed on QcrB inhibitors. Telacebec and TB47 are established QcrB inhibitors in the clinical trial. The inventive QcrB inhibitor-based drug combinations can potentially handle DRTB and reduce the TB therapy duration. The authors anticipate great opportunities in fostering QcrB inhibitor-based patentable pharmaceutical inventions against TB. Drug repurposing can be a promising strategy to get safe and effective QcrB inhibitors. However, developing drug resistance, drug tolerance, and selectivity of QcrB inhibitors for Mtb will be the main challenges in developing effective QcrB inhibitors. In conclusion, QcrB is a promising drug target for developing effective treatments for active, latent, and drug-resistant TB. Many inventive and patentable combinations and compositions of QcrB inhibitors with other anti-TB drugs are anticipated as future treatments for TB.
Collapse
Affiliation(s)
- Mohd Imran
- Department of Pharmaceutical Chemistry, College of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia.
| | - Nawaf M Alotaibi
- Department of Clinical Pharmacy, College of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia; Chemistry Department, College of Sciences and Arts, Northern Border University, Rafha 91911, Saudi Arabia
| | - Hamdy K Thabet
- Chemistry Department, College of Sciences and Arts, Northern Border University, Rafha 91911, Saudi Arabia
| | - Jamal A Alruwaili
- College of Applied Medical Sciences, Medical Lab Technology Department, Northern Border University, Arar 91431, Saudi Arabia
| | - Syed M B Asdaq
- Department of Pharmacy Practice, College of Pharmacy, AlMaarefa University, Dariyah, Riyadh 13713, Saudi Arabia
| | - Lina Eltaib
- Department of Pharmaceutics, College of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia
| | - Ahmed Alshehri
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Northern Border University, Rafha, Saudi Arabia; Department of Pharmacology, College of Clinical Pharmacy, Imam Abdulrahman Bin Faisal University, King Faisal Road, Dammam 31441, Saudi Arabia
| | - Ahad A Alsaiari
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Mazen Almehmadi
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | | | | |
Collapse
|
7
|
Kumar G, Kapoor S. Targeting mycobacterial membranes and membrane proteins: Progress and limitations. Bioorg Med Chem 2023; 81:117212. [PMID: 36804747 DOI: 10.1016/j.bmc.2023.117212] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/13/2023]
Abstract
Among the various bacterial infections, tuberculosis continues to hold center stage. Its causative agent, Mycobacterium tuberculosis, possesses robust defense mechanisms against most front-line antibiotic drugs and host responses due to their complex cell membranes with unique lipid molecules. It is now well-established that bacteria change their membrane composition to optimize their environment to survive and elude drug action. Thus targeting membrane or membrane components is a promising avenue for exploiting the chemical space focussed on developing novel membrane-centric anti-bacterial small molecules. These approaches are more effective, non-toxic, and can attenuate resistance phenotype. We present the relevance of targeting the mycobacterial membrane as a practical therapeutic approach. The review highlights the direct and indirect targeting of membrane structure and function. Direct membrane targeting agents cause perturbation in the membrane potential and can cause leakage of the cytoplasmic contents. In contrast, indirect membrane targeting agents disrupt the function of membrane-associated proteins involved in cell wall biosynthesis or energy production. We discuss the chronological chemical improvements in various scaffolds targeting specific membrane-associated protein targets, their clinical evaluation, and up-to-date account of their ''mechanisms of action, potency, selectivity'' and limitations. The sources of anti-TB drugs/inhibitors discussed in this work have emerged from target-based identification, cell-based phenotypic screening, drug repurposing, and natural products. We believe this review will inspire the exploration of uncharted chemical space for informing the development of new scaffolds that can inhibit novel mycobacterial membrane targets.
Collapse
Affiliation(s)
- Gautam Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Departemnt of Natural Products, National Institute of Pharmaceutical Education and Research-Hyderabad, Hyderabad 500037, India.
| | - Shobhna Kapoor
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India; Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima 739-8528, Japan.
| |
Collapse
|
8
|
Machine Learning Prediction of Mycobacterial Cell Wall Permeability of Drugs and Drug-like Compounds. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020633. [PMID: 36677691 PMCID: PMC9863426 DOI: 10.3390/molecules28020633] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 12/30/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023]
Abstract
The cell wall of Mycobacterium tuberculosis and related organisms has a very complex and unusual organization that makes it much less permeable to nutrients and antibiotics, leading to the low activity of many potential antimycobacterial drugs against whole-cell mycobacteria compared to their isolated molecular biotargets. The ability to predict and optimize the cell wall permeability could greatly enhance the development of novel antitubercular agents. Using an extensive structure-permeability dataset for organic compounds derived from published experimental big data (5371 compounds including 2671 penetrating and 2700 non-penetrating compounds), we have created a predictive classification model based on fragmental descriptors and an artificial neural network of a novel architecture that provides better accuracy (cross-validated balanced accuracy 0.768, sensitivity 0.768, specificity 0.769, area under ROC curve 0.911) and applicability domain compared with the previously published results.
Collapse
|
9
|
Wani MA, Dhaked DK. Targeting the cytochrome bc 1 complex for drug development in M. tuberculosis: review. Mol Divers 2021; 26:2949-2965. [PMID: 34762234 DOI: 10.1007/s11030-021-10335-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/04/2021] [Indexed: 11/26/2022]
Abstract
The terminal oxidases of the oxidative phosphorylation pathway play a significant role in the survival and growth of M. tuberculosis, targeting these components lead to inhibition of M. tuberculosis. Many drug candidates targeting various components of the electron transport chain in M. tuberculosis have recently been discovered. The cytochrome bc1-aa3 supercomplex is one of the most important components of the electron transport chain in M. tuberculosis, and it has emerged as the novel target for several promising candidates. There are two cryo-electron microscopy structures (PDB IDs: 6ADQ and 6HWH) of the cytochrome bc1-aa3 supercomplex that aid in the development of effective and potent inhibitors for M. tuberculosis. In recent years, a number of potential candidates targeting the QcrB subunit of the cytochrome bc1 complex have been developed. In this review, we describe the recently identified inhibitors that target the electron transport chain's terminal oxidase enzyme in M. tuberculosis, specifically the QcrB subunit of the cytochrome bc1 complex.
Collapse
Affiliation(s)
- Mushtaq Ahmad Wani
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, West Bengal, 700054, India
| | - Devendra Kumar Dhaked
- Department of Pharmacoinformatics, National Institute of Pharmaceutical Education and Research (NIPER)-Kolkata, Chunilal Bhawan, 168 Maniktala Main Road, Kolkata, West Bengal, 700054, India.
| |
Collapse
|
10
|
Bendre AD, Peters PJ, Kumar J. Recent Insights into the Structure and Function of Mycobacterial Membrane Proteins Facilitated by Cryo-EM. J Membr Biol 2021; 254:321-341. [PMID: 33954837 PMCID: PMC8099146 DOI: 10.1007/s00232-021-00179-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 03/23/2021] [Indexed: 12/26/2022]
Abstract
Mycobacterium tuberculosis (Mtb) is one of the deadliest pathogens encountered by humanity. Over the decades, its characteristic membrane organization and composition have been understood. However, there is still limited structural information and mechanistic understanding of the constituent membrane proteins critical for drug discovery pipelines. Recent advances in single-particle cryo-electron microscopy and cryo-electron tomography have provided the much-needed impetus towards structure determination of several vital Mtb membrane proteins whose structures were inaccessible via X-ray crystallography and NMR. Important insights into membrane composition and organization have been gained via a combination of electron tomography and biochemical and biophysical assays. In addition, till the time of writing this review, 75 new structures of various Mtb proteins have been reported via single-particle cryo-EM. The information obtained from these structures has improved our understanding of the mechanisms of action of these proteins and the physiological pathways they are associated with. These structures have opened avenues for structure-based drug design and vaccine discovery programs that might help achieve global-TB control. This review describes the structural features of selected membrane proteins (type VII secretion systems, Rv1819c, Arabinosyltransferase, Fatty Acid Synthase, F-type ATP synthase, respiratory supercomplex, ClpP1P2 protease, ClpB disaggregase and SAM riboswitch), their involvement in physiological pathways, and possible use as a drug target. Tuberculosis is a deadly disease caused by Mycobacterium tuberculosis. The Cryo-EM and tomography have simplified the understanding of the mycobacterial membrane organization. Some proteins are located in the plasma membrane; some span the entire envelope, while some, like MspA, are located in the mycomembrane. Cryo-EM has made the study of such membrane proteins feasible.
Collapse
Affiliation(s)
- Ameya D Bendre
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University Campus, Ganeshkhind, Pune, Maharashtra, 411007, India
| | - Peter J Peters
- The Maastricht Multimodal Molecular Imaging Institute (M4I), Division of Nanoscopy, Maastricht University, Maastricht, The Netherlands
| | - Janesh Kumar
- Laboratory of Membrane Protein Biology, National Centre for Cell Science, NCCS Complex, S. P. Pune University Campus, Ganeshkhind, Pune, Maharashtra, 411007, India.
| |
Collapse
|
11
|
Falke D, Fischer M, Ihling C, Hammerschmidt C, Sinz A, Sawers G. Co-purification of nitrate reductase 1 with components of the cytochrome bcc-aa 3 oxidase supercomplex from spores of Streptomyces coelicolor A3(2). FEBS Open Bio 2021; 11:652-669. [PMID: 33462996 PMCID: PMC7931247 DOI: 10.1002/2211-5463.13086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 12/21/2020] [Accepted: 12/30/2020] [Indexed: 11/30/2022] Open
Abstract
In order to reduce nitrate in vivo, the spore‐specific respiratory nitrate reductase, Nar1, of Streptomyces coelicolor relies on an active cytochrome bcc‐aa3 oxidase supercomplex (bcc‐aa3 supercomplex). This suggests that membrane‐associated Nar1, comprising NarG1, NarH1, and NarI1 subunits, might not act as a classical menaquinol oxidase but could either receive electrons from the bcc‐aa3 supercomplex, or require the supercomplex to stabilize the reductase in the membrane to allow it to function. To address the biochemical basis for this dependence on the bcc‐aa3 supercomplex, we purified two different Strep‐tagged variants of Nar1 and enriched the native enzyme complex from spore extracts using different chromatographic and electrophoretic procedures. Polypeptides associated with the isolated Nar1 complexes were identified using mass spectrometry and included components of the bcc‐aa3 supercomplex, along with an alternative, spore‐specific cytochrome b component, QcrB3. Surprisingly, we also co‐enriched the Nar3 enzyme with Nar1 from the wild‐type strain of S. coelicolor. Two differentially migrating active Nar1 complexes could be identified after clear native polyacrylamide gel electrophoresis; these had masses of approximately 450 and 250 kDa. The distribution of active Nar1 in these complexes was influenced by the presence of cytochrome bd oxidase and by QcrB3; the presence of the latter shifted Nar1 into the larger complex. Together, these data suggest that several respiratory complexes can associate in the spore membrane, including Nar1, Nar3, and the bcc‐aa3 supercomplex. Moreover, these findings provide initial support for the hypothesis that Nar1 and the bcc‐aa3 supercomplex physically associate.
Collapse
Affiliation(s)
- Dörte Falke
- Institute of Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Marco Fischer
- Institute of Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Christian Ihling
- Institute of Pharmacy, Charles Tanford Protein Center, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Claudia Hammerschmidt
- Institute of Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Andrea Sinz
- Institute of Pharmacy, Charles Tanford Protein Center, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Gary Sawers
- Institute of Microbiology, Martin-Luther University Halle-Wittenberg, Halle (Saale), Germany
| |
Collapse
|
12
|
Small organic molecules targeting the energy metabolism of Mycobacterium tuberculosis. Eur J Med Chem 2020; 212:113139. [PMID: 33422979 DOI: 10.1016/j.ejmech.2020.113139] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 11/21/2022]
Abstract
Causing approximately 10 million incident cases and 1.3-1.5 million deaths every year, Mycobacterium tuberculosis remains a global health problem. The risk is further exacerbated with latent tuberculosis (TB) infection, the HIV pandemic, and increasing anti-TB drug resistance. Therefore, unexplored chemical scaffolds directed towards new molecular targets are increasingly desired. In this context, mycobacterial energy metabolism, particularly the oxidative phosphorylation (OP) pathway, is gaining importance. Mycobacteria possess primary dehydrogenases to fuel electron transport; aa3-type cytochrome c oxidase and bd-type menaquinol oxidase to generate a protonmotive force; and ATP synthase, which is essential for both growing mycobacteria as well as dormant mycobacteria because ATP is produced under both aerobic and hypoxic conditions. Small organic molecules targeting OP are active against latent TB as well as resistant TB strains. FDA approval of the ATP synthase inhibitor bedaquiline and the discovery of clinical candidate Q203, which both interfere with the cytochrome bc1 complex, have already confirmed mycobacterial energy metabolism to be a valuable anti-TB drug target. This review highlights both preferable molecular targets within mycobacterial OP and promising small organic molecules targeting OP. Progressive research in the area of mycobacterial OP revealed several highly potent anti-TB compounds with nanomolar-range MICs as low as 0.004 μM against Mtb H37Rv. Therefore, we are convinced that targeting the OP pathway can combat resistant TB and latent TB, leading to more efficient anti-TB chemotherapy.
Collapse
|
13
|
Abstract
After several years of limited success, an effective regimen for the treatment of both drug-sensitive and multiple-drug-resistant tuberculosis is in place. However, this success is still incomplete, as we need several more novel combinations to treat extensively drug-resistant tuberculosis, as well newer emerging resistance. Additionally, the goal of a shortened therapy continues to evade us. A systematic analysis of the tuberculosis drug discovery approaches employed over the last two decades shows that the lead identification path has been largely influenced by the improved understanding of the biology of the pathogen Mycobacterium tuberculosis. Interestingly, the drug discovery efforts can be grouped into a few defined approaches that predominated over a period of time. This review delineates the key drivers during each of these periods. While doing so, the author’s experiences at AstraZeneca R&D, Bangalore, India, on the discovery of new antimycobacterial candidate drugs are used to exemplify the concept. Finally, the review also discusses the value of validated targets, promiscuous targets, the current anti-TB pipeline, the gaps in it, and the possible way forward.
Collapse
|