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Butler MS, Vollmer W, Goodall ECA, Capon RJ, Henderson IR, Blaskovich MAT. A Review of Antibacterial Candidates with New Modes of Action. ACS Infect Dis 2024. [PMID: 39018341 DOI: 10.1021/acsinfecdis.4c00218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/19/2024]
Abstract
There is a lack of new antibiotics to combat drug-resistant bacterial infections that increasingly threaten global health. The current pipeline of clinical-stage antimicrobials is primarily populated by "new and improved" versions of existing antibiotic classes, supplemented by several novel chemical scaffolds that act on traditional targets. The lack of fresh chemotypes acting on previously unexploited targets (the "holy grail" for new antimicrobials due to their scarcity) is particularly unfortunate as these offer the greatest opportunity for innovative breakthroughs to overcome existing resistance. In recognition of their potential, this review focuses on this subset of high value antibiotics, providing chemical structures where available. This review focuses on candidates that have progressed to clinical trials, as well as selected examples of promising pioneering approaches in advanced stages of development, in order to stimulate additional research aimed at combating drug-resistant infections.
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Affiliation(s)
- Mark S Butler
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Waldemar Vollmer
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Emily C A Goodall
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Robert J Capon
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Ian R Henderson
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Mark A T Blaskovich
- Centre for Superbug Solutions and ARC Training Centre for Environmental and Agricultural Solutions to Antimicrobial Resistance, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland 4072, Australia
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2
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Zaib S, Khan I, Ali HS, Younas MT, Ibrar A, Al-Odayni AB, Al-Kahtani AA. Design and discovery of anthranilamide derivatives as a potential treatment for neurodegenerative disorders via targeting cholinesterases and monoamine oxidases. Int J Biol Macromol 2024; 272:132748. [PMID: 38821306 DOI: 10.1016/j.ijbiomac.2024.132748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 05/26/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Neurodegenerative diseases with progressive cellular loss of the central nervous system and elusive disease etiology provide a continuous impetus to explore drug discovery programmes aiming at identifying robust and effective inhibitors of cholinesterase and monoamine oxidase enzymes. We herein present a concise library of anthranilamide derivatives involving a palladium-catalyzed Suzuki-Miyaura cross-coupling reaction to install the diverse structural diversity required for the desired biological action. Using Ellman's method, cholinesterase inhibitory activity was performed against AChE and BuChE enzymes. In vitro assay results demonstrated that anthranilamides are potent inhibitors with remarkable potency. Compound 6k emerged as the lead candidate and dual inhibitor of both enzymes with IC50 values of 0.12 ± 0.01 and 0.49 ± 0.02 μM against AChE and BuChE, respectively. Several other compounds were found as highly potent and selective inhibitors. Anthranilamide derivatives were also tested against monoamine oxidase (A and B) enzymes using fluorometric method. In vitro data revealed compound 6h as the most potent inhibitor against MAO-A, showing an IC50 value of 0.44 ± 0.02 μM, whereas, compound 6k emerged as the top inhibitor of MAO-B with an IC50 value of 0.06 ± 0.01 μM. All the lead inhibitors were analyzed for the identification of their mechanism of action using Michaelis-Menten kinetics experiments. Compound 6k and 6h depicted a competitive mode of action against AChE and MAO-A, whereas, a non-competitive and mixed-type of inhibition was observed against BuChE and MAO-B by compounds 6k. Molecular docking analysis revealed remarkable binding affinities of the potent inhibitors with specific residues inside the active site of receptors. Furthermore, molecular dynamics simulations were performed to explore the ability of potent compounds to form energetically stable complexes with the target protein. Finally, in silico ADME calculations also demonstrated that the potent compounds exhibit promising pharmacokinetic profile, satisfying the essential criteria for drug-likeness. Altogether, the findings reported in the current work clearly suggest that the identified anthranilamide derivatives have the potential to serve as effective drug candidates for future investigations.
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Affiliation(s)
- Sumera Zaib
- Department of Basic and Applied Chemistry, Faculty of Science and Technology, University of Central Punjab, Lahore 54590, Pakistan.
| | - Imtiaz Khan
- Department of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester MI 7DN, UK.
| | - Hafiz Saqib Ali
- Chemistry Research Laboratory, Department of Chemistry, the INEOS Oxford Institute for Antimicrobial Research, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, UK
| | - Muhammad Tayyab Younas
- Department of Basic and Applied Chemistry, Faculty of Science and Technology, University of Central Punjab, Lahore 54590, Pakistan
| | - Aliya Ibrar
- Department of Chemistry, Faculty of Physical and Applied Sciences, The University of Haripur, Haripur, KPK 22620, Pakistan.
| | - Abdel-Basit Al-Odayni
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia
| | - Abdullah A Al-Kahtani
- Chemistry Department, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia
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3
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Suigo L, Monterroso B, Sobrinos-Sanguino M, Alfonso C, Straniero V, Rivas G, Zorrilla S, Valoti E, Margolin W. Benzodioxane-benzamides as promising inhibitors of Escherichia coli FtsZ. Int J Biol Macromol 2023; 253:126398. [PMID: 37634788 DOI: 10.1016/j.ijbiomac.2023.126398] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/02/2023] [Accepted: 08/16/2023] [Indexed: 08/29/2023]
Abstract
The conserved process of cell division in bacteria has been a long-standing target for antimicrobials, although there are few examples of potent broad-spectrum compounds that inhibit this process. Most currently available compounds acting on division are directed towards the FtsZ protein, a self-assembling GTPase that is a central element of the division machinery in most bacteria. Benzodioxane-benzamides are promising candidates, but poorly explored in Gram-negatives. We have tested a number of these compounds on E. coli FtsZ and found that many of them significantly stabilized the polymers against disassembly and reduced the GTPase activity. Reconstitution in crowded cell-like conditions showed that FtsZ bundles were also susceptible to these compounds, including some compounds that were inactive on protofilaments in dilute conditions. They efficiently killed E. coli cells defective in the AcrAB efflux pump. The activity of the compounds on cell growth and division generally showed a good correlation with their effect in vitro, and our experiments are consistent with FtsZ being the target in vivo. Our results uncover the detrimental effects of benzodioxane-benzamides on permeable E. coli cells via its central division protein, implying that lead compounds may be found within this class for the development of antibiotics against Gram-negative bacteria.
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Affiliation(s)
- Lorenzo Suigo
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Marta Sobrinos-Sanguino
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Carlos Alfonso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Valentina Straniero
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain
| | - Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), 28040 Madrid, Spain.
| | - Ermanno Valoti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy.
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston 77030, TX, USA.
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4
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Suigo L, Margolin W, Ulzurrun E, Hrast Rambaher M, Zanotto C, Sebastián-Pérez V, Campillo NE, Straniero V, Valoti E. Benzodioxane-Benzamides as FtsZ Inhibitors: Effects of Linker's Functionalization on Gram-Positive Antimicrobial Activity. Antibiotics (Basel) 2023; 12:1712. [PMID: 38136746 PMCID: PMC10740499 DOI: 10.3390/antibiotics12121712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
FtsZ is an essential bacterial protein abundantly studied as a novel and promising target for antimicrobials. FtsZ is highly conserved among bacteria and mycobacteria, and it is crucial for the correct outcome of the cell division process, as it is responsible for the division of the parent bacterial cell into two daughter cells. In recent years, the benzodioxane-benzamide class has emerged as very promising and capable of targeting both Gram-positive and Gram-negative FtsZs. In this study, we explored the effect of including a substituent on the ethylenic linker between the two main moieties on the antimicrobial activity and pharmacokinetic properties. This substitution, in turn, led to the generation of a second stereogenic center, with both erythro and threo isomers isolated, characterized, and evaluated. With this work, we discovered how the hydroxy group slightly affects the antimicrobial activity, while being an important anchor for the exploitation and development of prodrugs, probes, and further derivatives.
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Affiliation(s)
- Lorenzo Suigo
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas, Houston, TX 77030, USA;
| | - Eugenia Ulzurrun
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas (CSIC), Darwin 3, 28049 Madrid, Spain
| | - Martina Hrast Rambaher
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva Cesta, 7, 1000 Ljubljana, Slovenia;
| | - Carlo Zanotto
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Via Vanvitelli, 32, 20129 Milano, Italy;
| | - Victor Sebastián-Pérez
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Exscientia, The Schrödinger Building, Oxford Science Park, Oxford OX4 4GE, UK
| | - Nuria E. Campillo
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Ramiro de Maeztu 9, 28040 Madrid, Spain; (E.U.); (V.S.-P.); (N.E.C.)
- Instituto de Ciencias Matemáticas, Consejo Superior de Investigaciones Científicas (CSIC), C. Nicolás Cabrera, 13-15, 28049 Madrid, Italy
| | - Valentina Straniero
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
| | - Ermanno Valoti
- Dipartimento di Scienze Farmaceutiche, Università degli Studi di Milano, Via Luigi Mangiagalli, 25, 20133 Milano, Italy; (L.S.); (E.V.)
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5
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Theuretzbacher U, Blasco B, Duffey M, Piddock LJV. Unrealized targets in the discovery of antibiotics for Gram-negative bacterial infections. Nat Rev Drug Discov 2023; 22:957-975. [PMID: 37833553 DOI: 10.1038/s41573-023-00791-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/15/2023] [Indexed: 10/15/2023]
Abstract
Advances in areas that include genomics, systems biology, protein structure determination and artificial intelligence provide new opportunities for target-based antibacterial drug discovery. The selection of a 'good' new target for direct-acting antibacterial compounds is the first decision, for which multiple criteria must be explored, integrated and re-evaluated as drug discovery programmes progress. Criteria include essentiality of the target for bacterial survival, its conservation across different strains of the same species, bacterial species and growth conditions (which determines the spectrum of activity of a potential antibiotic) and the level of homology with human genes (which influences the potential for selective inhibition). Additionally, a bacterial target should have the potential to bind to drug-like molecules, and its subcellular location will govern the need for inhibitors to penetrate one or two bacterial membranes, which is a key challenge in targeting Gram-negative bacteria. The risk of the emergence of target-based drug resistance for drugs with single targets also requires consideration. This Review describes promising but as-yet-unrealized targets for antibacterial drugs against Gram-negative bacteria and examples of cognate inhibitors, and highlights lessons learned from past drug discovery programmes.
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Affiliation(s)
| | - Benjamin Blasco
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland
| | - Maëlle Duffey
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland
| | - Laura J V Piddock
- Global Antibiotic Research and Development Partnership (GARDP), Geneva, Switzerland.
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6
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Kadeřábková N, Mahmood AJS, Furniss RCD, Mavridou DAI. Making a chink in their armor: Current and next-generation antimicrobial strategies against the bacterial cell envelope. Adv Microb Physiol 2023; 83:221-307. [PMID: 37507160 PMCID: PMC10517717 DOI: 10.1016/bs.ampbs.2023.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2023]
Abstract
Gram-negative bacteria are uniquely equipped to defeat antibiotics. Their outermost layer, the cell envelope, is a natural permeability barrier that contains an array of resistance proteins capable of neutralizing most existing antimicrobials. As a result, its presence creates a major obstacle for the treatment of resistant infections and for the development of new antibiotics. Despite this seemingly impenetrable armor, in-depth understanding of the cell envelope, including structural, functional and systems biology insights, has promoted efforts to target it that can ultimately lead to the generation of new antibacterial therapies. In this article, we broadly overview the biology of the cell envelope and highlight attempts and successes in generating inhibitors that impair its function or biogenesis. We argue that the very structure that has hampered antibiotic discovery for decades has untapped potential for the design of novel next-generation therapeutics against bacterial pathogens.
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Affiliation(s)
- Nikol Kadeřábková
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States
| | - Ayesha J S Mahmood
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States
| | - R Christopher D Furniss
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Despoina A I Mavridou
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, United States; John Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, TX, United States.
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7
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Sharma AK, Poddar SM, Chakraborty J, Nayak BS, Kalathil S, Mitra N, Gayathri P, Srinivasan R. A mechanism of salt bridge-mediated resistance to FtsZ inhibitor PC190723 revealed by a cell-based screen. Mol Biol Cell 2023; 34:ar16. [PMID: 36652338 PMCID: PMC10011733 DOI: 10.1091/mbc.e22-12-0538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Bacterial cell division proteins, especially the tubulin homologue FtsZ, have emerged as strong targets for developing new antibiotics. Here, we have utilized the fission yeast heterologous expression system to develop a cell-based assay to screen for small molecules that directly and specifically target the bacterial cell division protein FtsZ. The strategy also allows for simultaneous assessment of the toxicity of the drugs to eukaryotic yeast cells. As a proof-of-concept of the utility of this assay, we demonstrate the effect of the inhibitors sanguinarine, berberine, and PC190723 on FtsZ. Though sanguinarine and berberine affect FtsZ polymerization, they exert a toxic effect on the cells. Further, using this assay system, we show that PC190723 affects Helicobacter pylori FtsZ function and gain new insights into the molecular determinants of resistance to PC190723. On the basis of sequence and structural analysis and site-specific mutations, we demonstrate that the presence of salt bridge interactions between the central H7 helix and β-strands S9 and S10 mediates resistance to PC190723 in FtsZ. The single-step in vivo cell-based assay using fission yeast enabled us to dissect the contribution of sequence-specific features of FtsZ and cell permeability effects associated with bacterial cell envelopes. Thus, our assay serves as a potent tool to rapidly identify novel compounds targeting polymeric bacterial cytoskeletal proteins like FtsZ to understand how they alter polymerization dynamics and address resistance determinants in targets.
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Affiliation(s)
- Ajay Kumar Sharma
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Sakshi Mahesh Poddar
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Joyeeta Chakraborty
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Bhagyashri Soumya Nayak
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Srilakshmi Kalathil
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Nivedita Mitra
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
| | - Pananghat Gayathri
- Biology, Indian Institute of Science Education and Research, Pune 411008, India
| | - Ramanujam Srinivasan
- School of Biological Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Centre for Interdisciplinary Sciences, National Institute of Science Education and Research, Bhubaneswar 752050, India.,Homi Bhabha National Institutes, Anushakti Nagar, Mumbai 400094, India
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8
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Models versus pathogens: how conserved is the FtsZ in bacteria? Biosci Rep 2023; 43:232502. [PMID: 36695643 PMCID: PMC9939409 DOI: 10.1042/bsr20221664] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/10/2023] [Accepted: 01/25/2023] [Indexed: 01/26/2023] Open
Abstract
Combating anti-microbial resistance by developing alternative strategies is the need of the hour. Cell division, particularly FtsZ, is being extensively studied for its potential as an alternative target for anti-bacterial therapy. Bacillus subtilis and Escherichia coli are the two well-studied models for research on FtsZ, the leader protein of the cell division machinery. As representatives of gram-positive and gram-negative bacteria, respectively, these organisms have provided an extensive outlook into the process of cell division in rod-shaped bacteria. However, research on other shapes of bacteria, like cocci and ovococci, lags behind that of model rods. Even though most regions of FtsZ show sequence and structural conservation throughout bacteria, the differences in FtsZ functioning and interacting partners establish several different modes of division in different bacteria. In this review, we compare the features of FtsZ and cell division in the model rods B. subtilis and E. coli and the four pathogens: Staphylococcus aureus, Streptococcus pneumoniae, Mycobacterium tuberculosis, and Pseudomonas aeruginosa. Reviewing several recent articles on these pathogenic bacteria, we have highlighted the functioning of FtsZ, the unique roles of FtsZ-associated proteins, and the cell division processes in them. Further, we provide a detailed look at the anti-FtsZ compounds discovered and their target bacteria, emphasizing the need for elucidation of the anti-FtsZ mechanism of action in different bacteria. Current challenges and opportunities in the ongoing journey of identifying potent anti-FtsZ drugs have also been described.
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9
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Chai WC, Whittall JJ, Polyak SW, Foo K, Li X, Dutschke CJ, Ogunniyi AD, Ma S, Sykes MJ, Semple SJ, Venter H. Cinnamaldehyde derivatives act as antimicrobial agents against Acinetobacter baumannii through the inhibition of cell division. Front Microbiol 2022; 13:967949. [PMID: 36106080 PMCID: PMC9465178 DOI: 10.3389/fmicb.2022.967949] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
Acinetobacter baumannii is a pathogen with high intrinsic antimicrobial resistance while multidrug resistant (MDR) and extensively drug resistant (XDR) strains of this pathogen are emerging. Treatment options for infections by these strains are very limited, hence new therapies are urgently needed. The bacterial cell division protein, FtsZ, is a promising drug target for the development of novel antimicrobial agents. We have previously reported limited activity of cinnamaldehyde analogs against Escherichia coli. In this study, we have determined the antimicrobial activity of six cinnamaldehyde analogs for antimicrobial activity against A. baumannii. Microscopic analysis was performed to determine if the compounds inhibit cell division. The on-target effect of the compounds was assessed by analyzing their effect on polymerization and on the GTPase activity of purified FtsZ from A. baumannii. In silico docking was used to assess the binding of cinnamaldehyde analogs. Finally, in vivo and in vitro safety assays were performed. All six compounds displayed antibacterial activity against the critical priority pathogen A. baumannii, with 4-bromophenyl-substituted 4 displaying the most potent antimicrobial activity (MIC 32 μg/mL). Bioactivity was significantly increased in the presence of an efflux pump inhibitor for A. baumannii ATCC 19606 (up to 32-fold) and significantly, for extensively drug resistant UW 5075 (greater than 4-fold), suggesting that efflux contributes to the intrinsic resistance of A. baumannii against these agents. The compounds inhibited cell division in A. baumannii as observed by the elongated phenotype and targeted the FtsZ protein as seen from the inhibition of polymerization and GTPase activity. In silico docking predicted that the compounds bind in the interdomain cleft adjacent to the H7 core helix. Di-chlorinated 6 was devoid of hemolytic activity and cytotoxicity against mammalian cells in vitro, as well as adverse activity in a Caenorhabditis elegans nematode model in vivo. Together, these findings present halogenated analogs 4 and 6 as promising candidates for further development as antimicrobial agents aimed at combating A. baumannii. This is also the first report of FtsZ-targeting compounds with activity against an XDR A. baumannii strain.
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Affiliation(s)
- Wern Chern Chai
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Jonathan J. Whittall
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Steven W. Polyak
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Klyie Foo
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Xin Li
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Cameron J. Dutschke
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Abiodun D. Ogunniyi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Shutao Ma
- Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Matthew J. Sykes
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Susan J. Semple
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Quality Use of Medicines and Pharmacy Research Centre, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- *Correspondence: Henrietta Venter,
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10
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Andreu JM, Huecas S, Araújo-Bazán L, Vázquez-Villa H, Martín-Fontecha M. The Search for Antibacterial Inhibitors Targeting Cell Division Protein FtsZ at Its Nucleotide and Allosteric Binding Sites. Biomedicines 2022; 10:biomedicines10081825. [PMID: 36009372 PMCID: PMC9405007 DOI: 10.3390/biomedicines10081825] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/18/2022] [Accepted: 07/25/2022] [Indexed: 11/18/2022] Open
Abstract
The global spread of bacterial antimicrobial resistance is associated to millions of deaths from bacterial infections per year, many of which were previously treatable. This, combined with slow antibiotic deployment, has created an urgent need for developing new antibiotics. A still clinically unexploited mode of action consists in suppressing bacterial cell division. FtsZ, an assembling GTPase, is the key protein organizing division in most bacteria and an attractive target for antibiotic discovery. Nevertheless, developing effective antibacterial inhibitors targeting FtsZ has proven challenging. Here we review our decade-long multidisciplinary research on small molecule inhibitors of bacterial division, in the context of global efforts to discover FtsZ-targeting antibiotics. We focus on methods to characterize synthetic inhibitors that either replace bound GTP from the FtsZ nucleotide binding pocket conserved across diverse bacteria or selectively bind into the allosteric site at the interdomain cleft of FtsZ from Bacillus subtilis and the pathogen Staphylococcus aureus. These approaches include phenotype screening combined with fluorescence polarization screens for ligands binding into each site, followed by detailed cytological profiling, and biochemical and structural studies. The results are analyzed to design an optimized workflow to identify effective FtsZ inhibitors, and new approaches for the discovery of FtsZ-targeting antibiotics are discussed.
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Affiliation(s)
- José M. Andreu
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; (S.H.); (L.A.-B.)
- Correspondence: (J.M.A.); (M.M.-F.)
| | - Sonia Huecas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; (S.H.); (L.A.-B.)
| | - Lidia Araújo-Bazán
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain; (S.H.); (L.A.-B.)
| | - Henar Vázquez-Villa
- Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain;
| | - Mar Martín-Fontecha
- Departamento de Química Orgánica, Facultad de Óptica y Optometría, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid, Spain
- Correspondence: (J.M.A.); (M.M.-F.)
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