1
|
Lokhande KB, Pawar SV, Madkaiker S, Shrivastava A, Venkateswara SK, Nawani N, Wani M, Ghosh P, Singh A. Screening of potential phytomolecules against MurG as drug target in nosocomial pathogen Pseudomonas aeruginosa: perceptions from computational campaign. J Biomol Struct Dyn 2024; 42:495-508. [PMID: 36974974 DOI: 10.1080/07391102.2023.2194005] [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: 10/19/2022] [Accepted: 03/15/2023] [Indexed: 03/29/2023]
Abstract
The nosocomial infection outbreak caused by Pseudomonas aeruginosa remains a public health concern. Multi-drug resistant (MDR) strains of P. aeruginosa are rapidly spreading leading to a huge mortality rate because of the unavailability of promising antimicrobials. MurG glycotransferase [UDP-N-acetylglucosamine-N-acetylmuramyl (pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase] is located at the plasma membrane and plays a key role in murein (peptidoglycan) biosynthesis in bacteria. Since MurG is required for bacterial cell wall synthesis and is non-homologous to Homo sapiens; it can be a potential target for the antagonist to treat P. aeruginosa infection. The discovery of high-resolution crystal structure of P. aeruginosa MurG offers an opportunity for the computational identification of its prospective inhibitors. Therefore, in the present study, the crystal structure of MurG (PDB ID: 3S2U) from P. aeruginosa was selected, and computational docking analyses were performed to search for functional inhibitors of MurG. IMPPAT (Indian medicinal plants, phytochemicals and therapeutic) phytomolecule database was screened by computational methods with MurG catalytic site. Docking results identified Theobromine (-8.881 kcal/mol), demethoxycurcumin (-8.850 kcal/mol), 2-alpha-hydroxycostic acid (-8.791 kcal/mol), aurantiamide (-8.779 kcal/mol) and petasiphenol (-8.685 kcal/mol) as a potential inhibitor of the MurG activity. Further, theobromine and demethoxycurcumin were subjected to MDS (molecular dynamics simulation) and free energy (MM/GBSA) analysis to comprehend the physiological state and structural stability of MurG-phytomolecules complexes. The outcomes suggested that these two phytomolecules could act as most favorable natural hit compounds for impeding the enzymatic action of MurG in P. aeruginosa, and thus it needs further validation by both in vitro and in vivo analysis. HIGHLIGHTSThe top phytomolecules such as theobromine, demethoxycurcumin, 2-alpha-hydroxycostic acid, aurantiamide and petasiphenol displayed promising binding with MurG catalytic domain.MurG complexed with theobromine and demethoxycurcumin showed the best interaction and stable by MD simulation at 100 ns.The outcome of MurG binding phytomolecules has expanded the possibility of hit phytomolecules validation.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Kiran Bharat Lokhande
- Bioinformatics Research Laboratory, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
| | - Sarika Vishnu Pawar
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
| | - Smriti Madkaiker
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
| | - Ashish Shrivastava
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
| | - Swamy K Venkateswara
- MIT School of Bioengineering Sciences & Research, MIT Art, Design and Technology University, Pune, Maharashtra, India
| | - Neelu Nawani
- Microbial Diversity Research Centre, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
| | - Minal Wani
- Plant and Environmental Biotechnology Research Laboratory, Dr. D. Y. Patil Biotechnology and Bioinformatics Institute, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, India
| | - Payel Ghosh
- Bioinformatics Centre, Savitribai Phule Pune University, Pune, Maharashtra, India
| | - Ashutosh Singh
- Translational Bioinformatics and Computational Genomics Research Lab, Department of Life Sciences, Shiv Nadar Institution of Eminence, Gautam Buddha Nagar, Uttar Pradesh, India
| |
Collapse
|
2
|
Hervin V, Roy V, Agrofoglio LA. Antibiotics and Antibiotic Resistance-Mur Ligases as an Antibacterial Target. Molecules 2023; 28:8076. [PMID: 38138566 PMCID: PMC10745416 DOI: 10.3390/molecules28248076] [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: 07/29/2023] [Revised: 11/09/2023] [Accepted: 12/11/2023] [Indexed: 12/24/2023] Open
Abstract
The emergence of Multidrug Resistance (MDR) strains of bacteria has accelerated the search for new antibacterials. The specific bacterial peptidoglycan biosynthetic pathway represents opportunities for the development of novel antibacterial agents. Among the enzymes involved, Mur ligases, described herein, and especially the amide ligases MurC-F are key targets for the discovery of multi-inhibitors, as they share common active sites and structural features.
Collapse
Affiliation(s)
| | - Vincent Roy
- ICOA UMR CNRS 7311, Université d’Orléans et CNRS, Rue de Chartres, 45067 Orléans, France;
| | - Luigi A. Agrofoglio
- ICOA UMR CNRS 7311, Université d’Orléans et CNRS, Rue de Chartres, 45067 Orléans, France;
| |
Collapse
|
3
|
Roman G. Thiophene-containing compounds with antimicrobial activity. Arch Pharm (Weinheim) 2022; 355:e2100462. [PMID: 35289443 DOI: 10.1002/ardp.202100462] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 12/19/2022]
Abstract
Thiophene, as a member of the group of five-membered heterocycles containing one heteroatom, is one of the simplest heterocyclic systems. Many synthetic strategies allow the accurate positioning of various functionalities onto the thiophene ring. This review provides a comprehensive, systematic and detailed account of the developments in the field of antimicrobial compounds featuring at least one thiophene ring in their structure, over the last decade.
Collapse
Affiliation(s)
- Gheorghe Roman
- Department of Inorganic Polymers, Petru Poni Institute of Macromolecular Chemistry, Iaşi, Romania
| |
Collapse
|
4
|
Azam MA, Singh A. Molecular insight into the binding mode of thieno[3,2-c]pyrazol-3-ols with Streptococcus pneumoniae MurF enzyme by combined molecular modeling approach. Struct Chem 2022. [DOI: 10.1007/s11224-021-01866-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Azam MA, Manoj VCV. An explorative study on diarylquinoline-based inhibitor targeting Enterococcus faecium MurF. Struct Chem 2020. [DOI: 10.1007/s11224-020-01622-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
6
|
Maitra A, Munshi T, Healy J, Martin LT, Vollmer W, Keep NH, Bhakta S. Cell wall peptidoglycan in Mycobacterium tuberculosis: An Achilles' heel for the TB-causing pathogen. FEMS Microbiol Rev 2020; 43:548-575. [PMID: 31183501 PMCID: PMC6736417 DOI: 10.1093/femsre/fuz016] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 06/07/2019] [Indexed: 02/06/2023] Open
Abstract
Tuberculosis (TB), caused by the intracellular pathogen Mycobacterium tuberculosis, remains one of the leading causes of mortality across the world. There is an urgent requirement to build a robust arsenal of effective antimicrobials, targeting novel molecular mechanisms to overcome the challenges posed by the increase of antibiotic resistance in TB. Mycobacterium tuberculosis has a unique cell envelope structure and composition, containing a peptidoglycan layer that is essential for maintaining cellular integrity and for virulence. The enzymes involved in the biosynthesis, degradation, remodelling and recycling of peptidoglycan have resurfaced as attractive targets for anti-infective drug discovery. Here, we review the importance of peptidoglycan, including the structure, function and regulation of key enzymes involved in its metabolism. We also discuss known inhibitors of ATP-dependent Mur ligases, and discuss the potential for the development of pan-enzyme inhibitors targeting multiple Mur ligases.
Collapse
Affiliation(s)
- Arundhati Maitra
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Tulika Munshi
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Jess Healy
- Department of Pharmaceutical and Biological Chemistry, UCL School of Pharmacy, 29-39 Brunswick Square, London WC1N 1AX, UK
| | - Liam T Martin
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK
| | - Nicholas H Keep
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, Department of Biological Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, UK
| |
Collapse
|
7
|
Amera GM, Khan RJ, Pathak A, Jha RK, Muthukumaran J, Singh AK. Computer aided ligand based screening for identification of promising molecules against enzymes involved in peptidoglycan biosynthetic pathway from Acinetobacter baumannii. Microb Pathog 2020; 147:104205. [PMID: 32353580 DOI: 10.1016/j.micpath.2020.104205] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/30/2022]
Abstract
A. baumannii has been considered as Priority-I as suggested by the World Health Organization (WHO) and the most critical pathogenic microorganism for causing nosocomial infection in imunno-compromised hospital-acquired patients due to multi-drug resistance (MDR). In the current study, we utilized "Computer-aided ligand-based virtual screening approach" for identification of promising molecules against Mur family proteins based on the known inhibitor (Naphthyl Tetronic Acids ((5Z)-3-(4-chlorophenyl)-4-hydroxy-5-(1-naphthylmethylene) furan-2(5H)-one)) of MurB from E. coli. The in-house library was prepared using a similarity search of a known inhibitor (Drug Bank ID: DB07296) against several relevant chemical databases. The molecules obtained from virtual screening of Naphthyl Tetronic Acids in-house library were successively subjected to physicochemical and ADMET screening. After this, the molecules which passed all the filters, subsequently subjected into interaction analysis with the drug target proteins (MurB, MurD, MurE and MurG) of A. baumanni and the results explained that four molecules were promising (CHEMBL468144, DB07296, Enamine_T5956969 and 54723243) for further molecular dynamics simulations. The free and ligand bounded proteins that undergone MD simulation are listed as follows: MurB, MurB-CHEMBL468144, MurB-DB07296, MurE, MurE-54723243, MurE-DB07296, MurD, MurD-Enamine_T5956969, MurD-DB07296, MurG, MurG-CHEMBL468144, and MurG-DB07296. Based on global and essential dynamics analysis, the stability order of molecules towards MurB (CHEMBL468144 > DB07296); MurD (Enamine_T5956969 > DB07296); MurE (54723243 > DB07296) and MurG (CHEMBL468144 > DB07296) indicates that the newly identified molecules are more promising one in comparison with the existing inhibitor. Based on all the docking and MD simulation results, the stability order of the free and ligand bounded protein are as follows; MurB and MurB-ligand complexes > MurD and MurD-ligand complexes > MurG and MurG-ligand complexes > MurE and MurE-ligand complexes. Finally, the selected compounds would be recommended for further experimental investigations and used as promising inhibitors of the infection caused by A. baumannii.
Collapse
Affiliation(s)
- Gizachew Muluneh Amera
- Department of Biotechnology, School of Engineering and Technology, Sharda University, P.C, 201310, Greater Noida, U.P, India
| | - Rameez Jabeer Khan
- Department of Biotechnology, School of Engineering and Technology, Sharda University, P.C, 201310, Greater Noida, U.P, India
| | - Amita Pathak
- Department of Chemistry, Indian Institute of Technology, HauzKhas, New Delhi, 110016, India
| | - Rajat Kumar Jha
- Department of Biotechnology, School of Engineering and Technology, Sharda University, P.C, 201310, Greater Noida, U.P, India
| | - Jayaraman Muthukumaran
- Department of Biotechnology, School of Engineering and Technology, Sharda University, P.C, 201310, Greater Noida, U.P, India
| | - Amit Kumar Singh
- Department of Biotechnology, School of Engineering and Technology, Sharda University, P.C, 201310, Greater Noida, U.P, India.
| |
Collapse
|
8
|
Shan L, Wenling Q, Mauro P, Stefano B. Antibacterial Agents Targeting the Bacterial Cell Wall. Curr Med Chem 2020; 27:2902-2926. [PMID: 32003656 DOI: 10.2174/0929867327666200128103653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/16/2019] [Accepted: 10/23/2019] [Indexed: 11/22/2022]
Abstract
The introduction of antibiotics to treat bacterial infections either by killing or blocking their growth has been accompanied by the studies of mechanism that allows the drugs to kill the bacteria or to stop their proliferation. In such a scenario, the emergence of antibacterial agents active on the bacterial cell wall has been of fundamental importance in the fight against bacterial agents responsible for severe diseases. As a matter of fact, the cell wall, which plays many roles during the lifecycle, is an essential constituent of most bacteria. This overview focuses on the intracellular steps of peptidoglycan biosynthesis and the research of new antibacterial agents based on the enzymes involved in these early steps of the formation of cell membrane components.
Collapse
Affiliation(s)
- Li Shan
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, 401331 Chongqing, China
| | - Qin Wenling
- Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, School of Pharmaceutical Sciences, Chongqing University, 401331 Chongqing, China
| | - Panunzio Mauro
- Isof-CNR Chemistry Department, Via Selmi, 2, 40126 Bologna, Italy
| | - Biondi Stefano
- BioVersys AG, C/o Technologiepark Basel, Hochbergerstrasse 60c, CH- 4057 Basel, Switzerland
| |
Collapse
|
9
|
Ahmad S, Raza S, Uddin R, Azam SS. Binding mode analysis, dynamic simulation and binding free energy calculations of the MurF ligase from Acinetobacter baumannii. J Mol Graph Model 2017; 77:72-85. [DOI: 10.1016/j.jmgm.2017.07.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/20/2017] [Accepted: 07/21/2017] [Indexed: 01/16/2023]
|
10
|
Azam MA, Jupudi S. Insight into the structural requirements of thiophene-3-carbonitriles-based MurF inhibitors by 3D-QSAR, molecular docking and molecular dynamics study. J Recept Signal Transduct Res 2017; 37:522-534. [PMID: 28768454 DOI: 10.1080/10799893.2017.1360354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The discovery of clinically relevant inhibitors against MurF enzyme has proven to be a challenging task. In order to get further insight into the structural features required for the MurF inhibitory activity, we performed pharmacophore and atom-based three-dimensional quantitative structure-activity relationship studies for novel thiophene-3-carbonitriles based MurF inhibitors. The five-feature pharmacophore model was generated using 48 inhibitors having IC50 values ranging from 0.18 to 663 μm. The best-fitted model showed a higher coefficient of determination (R2 = 0.978), cross-validation coefficient (Q2 = 0.8835) and Pearson coefficient (0.9406) at four component partial least-squares factor. The model was validated with external data set and enrichment study. The effectiveness of the docking protocol was validated by docking the co-crystallized ligand into the catalytic pocket of MurF enzyme. Further, binding free energy calculated by the molecular mechanics generalized Born surface area approach showed that van der Waals and non-polar solvation energy terms are the main contributors to ligand binding in the active site of MurF enzyme. A 10-ns molecular dynamic simulation was performed to confirm the stability of the 3ZM6-ligand complex. Four new molecules are also designed as potent MurF inhibitors. These results provide insights regarding the development of novel MurF inhibitors with better binding affinity.
Collapse
Affiliation(s)
- Mohammed Afzal Azam
- a Department of Pharmaceutical Chemistry , JSS College of Pharmacy (A Constituent College of Jagadguru Sri Sivarathreeswara University, Mysuru) , Udhagamandalam , India
| | - Srikanth Jupudi
- a Department of Pharmaceutical Chemistry , JSS College of Pharmacy (A Constituent College of Jagadguru Sri Sivarathreeswara University, Mysuru) , Udhagamandalam , India
| |
Collapse
|
11
|
Hrast M, Sosič I, Sink R, Gobec S. Inhibitors of the peptidoglycan biosynthesis enzymes MurA-F. Bioorg Chem 2014; 55:2-15. [PMID: 24755374 DOI: 10.1016/j.bioorg.2014.03.008] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 03/23/2014] [Accepted: 03/24/2014] [Indexed: 01/12/2023]
Abstract
The widespread emergence of resistant bacterial strains is becoming a serious threat to public health. This thus signifies the need for the development of new antibacterial agents with novel mechanisms of action. Continuous efforts in the design of novel antibacterials remain one of the biggest challenges in drug development. In this respect, the Mur enzymes, MurA-F, that are involved in the formation of UDP-N-acetylmuramyl-pentapeptide can be genuinely considered as promising antibacterial targets. This review provides an in-depth insight into the recent developments in the field of inhibitors of the MurA-F enzymes. Special attention is also given to compounds that act as multiple inhibitors of two, three or more of the Mur enzymes. Moreover, the reasons for the lack of preclinically successful inhibitors and the challenges to overcome these hurdles in the next years are also debated.
Collapse
Affiliation(s)
- Martina Hrast
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Izidor Sosič
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Roman Sink
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Stanislav Gobec
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia.
| |
Collapse
|
12
|
Hrast M, Anderluh M, Knez D, Randall CP, Barreteau H, O'Neill AJ, Blanot D, Gobec S. Design, synthesis and evaluation of second generation MurF inhibitors based on a cyanothiophene scaffold. Eur J Med Chem 2014; 73:83-96. [DOI: 10.1016/j.ejmech.2013.11.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 11/15/2013] [Accepted: 11/24/2013] [Indexed: 11/29/2022]
|
13
|
Hrast M, Turk S, Sosič I, Knez D, Randall CP, Barreteau H, Contreras-Martel C, Dessen A, O'Neill AJ, Mengin-Lecreulx D, Blanot D, Gobec S. Structure-activity relationships of new cyanothiophene inhibitors of the essential peptidoglycan biosynthesis enzyme MurF. Eur J Med Chem 2013; 66:32-45. [PMID: 23786712 DOI: 10.1016/j.ejmech.2013.05.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 10/26/2022]
Abstract
Peptidoglycan is an essential component of the bacterial cell wall, and enzymes involved in its biosynthesis represent validated targets for antibacterial drug discovery. MurF catalyzes the final intracellular peptidoglycan biosynthesis step: the addition of D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc-L-Ala-γ-D-Glu-meso-DAP (or L-Lys). As MurF has no human counterpart, it represents an attractive target for the development of new antibacterial drugs. Using recently published cyanothiophene inhibitors of MurF from Streptococcus pneumoniae as a starting point, we designed and synthesized a series of structurally related derivatives and investigated their inhibition of MurF enzymes from different bacterial species. Systematic structural modifications of the parent compounds resulted in a series of nanomolar inhibitors of MurF from S. pneumoniae and micromolar inhibitors of MurF from Escherichia coli and Staphylococcus aureus. Some of the inhibitors also show antibacterial activity against S. pneumoniae R6. These findings, together with two new co-crystal structures, represent an excellent starting point for further optimization toward effective novel antibacterials.
Collapse
Affiliation(s)
- Martina Hrast
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
The synthesis of the bacterial peptidoglycan has been recognized for over 50 years as fertile ground for antibacterial discovery. Initially, empirical screening of natural products for inhibition of bacterial growth detected many chemical classes of antibiotics whose specific mechanisms of action were eventually dissected and defined. Of the nontoxic antibiotics discovered, most were found to be inhibitors of either protein synthesis or cell wall synthesis, which led to more directed screening for inhibitors of these pathways. Directed screening and design programs for cell wall inhibitors have been undertaken since the 1960s. In that time it has become clear that, while certain steps and intermediates have yielded selective inhibitors and are established targets, other potential targets have not yielded inhibitors whose antibacterial activity is proven to be solely due to that inhibition. Why has this search been so problematic? Are the established targets still worth pursuing? This review will attempt to answer these and other questions and evaluate the viability of targets related to peptidoglycan synthesis.
Collapse
Affiliation(s)
- Lynn L Silver
- LL Silver Consulting, LLC, Springfield, New Jersey 07081, USA.
| |
Collapse
|
15
|
The Influence of Common Stimulus Parameters on Distortion Product Otoacoustic Emission Fine Structure. Ear Hear 2012; 33:239-49. [DOI: 10.1097/aud.0b013e3182321da4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
16
|
Abstract
The discovery of novel small-molecule antibacterial drugs has been stalled for many years. The purpose of this review is to underscore and illustrate those scientific problems unique to the discovery and optimization of novel antibacterial agents that have adversely affected the output of the effort. The major challenges fall into two areas: (i) proper target selection, particularly the necessity of pursuing molecular targets that are not prone to rapid resistance development, and (ii) improvement of chemical libraries to overcome limitations of diversity, especially that which is necessary to overcome barriers to bacterial entry and proclivity to be effluxed, especially in Gram-negative organisms. Failure to address these problems has led to a great deal of misdirected effort.
Collapse
Affiliation(s)
- Lynn L Silver
- LL Silver Consulting, LLC, 955 S. Springfield Ave., Unit C403, Springfield, NJ 07081, USA.
| |
Collapse
|
17
|
|
18
|
Gautam A, Vyas R, Tewari R. Peptidoglycan biosynthesis machinery: a rich source of drug targets. Crit Rev Biotechnol 2010; 31:295-336. [PMID: 21091161 DOI: 10.3109/07388551.2010.525498] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The range of antibiotic therapy for the control of bacterial infections is becoming increasingly limited because of the rapid rise in multidrug resistance in clinical bacterial isolates. A few diseases, such as tuberculosis, which were once thought to be under control, have re-emerged as serious health threats. These problems have resulted in intensified research to look for new inhibitors for bacterial pathogens. Of late, the peptidoglycan (PG) layer, the most important component of the bacterial cell wall has been the subject of drug targeting because, first, it is essential for the survivability of eubacteria and secondly, it is absent in humans. The last decade has seen tremendous inputs in deciphering the 3-D structures of the PG biosynthetic enzymes. Many inhibitors against these enzymes have been developed using virtual and high throughput screening techniques. This review discusses the mechanistic and structural properties of the PG biosynthetic enzymes and inhibitors developed in the last decade.
Collapse
Affiliation(s)
- Ankur Gautam
- Department of Biotechnology, Panjab University, Chandigarh, India
| | | | | |
Collapse
|
19
|
Turk S, Kovac A, Boniface A, Bostock JM, Chopra I, Blanot D, Gobec S. Discovery of new inhibitors of the bacterial peptidoglycan biosynthesis enzymes MurD and MurF by structure-based virtual screening. Bioorg Med Chem 2009; 17:1884-9. [PMID: 19223185 DOI: 10.1016/j.bmc.2009.01.052] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2008] [Revised: 01/19/2009] [Accepted: 01/22/2009] [Indexed: 11/18/2022]
Abstract
The ATP-dependent Mur ligases (MurC, MurD, MurE and MurF) successively add L-Ala, D-Glu, meso-A(2)pm or L-Lys, and D-Ala-D-Ala to the nucleotide precursor UDP-MurNAc, and they represent promising targets for antibacterial drug discovery. We have used the molecular docking programme eHiTS for the virtual screening of 1990 compounds from the National Cancer Institute 'Diversity Set' on MurD and MurF. The 50 top-scoring compounds from screening on each enzyme were selected for experimental biochemical evaluation. Our approach of virtual screening and subsequent in vitro biochemical evaluation of the best ranked compounds has provided four novel MurD inhibitors (best IC(50)=10 microM) and one novel MurF inhibitor (IC(50)=63 microM).
Collapse
Affiliation(s)
- Samo Turk
- Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia
| | | | | | | | | | | | | |
Collapse
|
20
|
Tomasić T, Zidar N, Rupnik V, Kovac A, Blanot D, Gobec S, Kikelj D, Masic LP. Synthesis and biological evaluation of new glutamic acid-based inhibitors of MurD ligase. Bioorg Med Chem Lett 2008; 19:153-7. [PMID: 19014883 DOI: 10.1016/j.bmcl.2008.10.129] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 10/28/2008] [Accepted: 10/29/2008] [Indexed: 12/18/2022]
Abstract
Mur ligases catalyze the biosynthesis of the UDP-MurNAc-pentapeptide precursor of peptidoglycan, an essential polymer of bacterial cell-wall. They constitute attractive targets for the development of novel antibacterial agents. Here we report on the synthesis of a series of 2,4-diaminoquinazolines, quinazoline-2,4(1H,3H)-diones, 5-benzylidenerhodanines and 5-benzylidenethiazolidine-2,4-diones and their inhibitory activities against MurD from Escherichia coli. Compounds (R)-27 and (S)-27 showed inhibitory activity against MurD with IC(50) values of 174 and 206 microM, respectively, which makes them promising starting points for optimization.
Collapse
Affiliation(s)
- Tihomir Tomasić
- University of Ljubljana, Faculty of Pharmacy, Ljubljana, Slovenia
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Šink R, Kovač A, Tomašić T, Rupnik V, Boniface A, Bostock J, Chopra I, Blanot D, Mašič LP, Gobec S, Zega A. Synthesis and Biological Evaluation ofN-Acylhydrazones as Inhibitors of MurC and MurD Ligases. ChemMedChem 2008; 3:1362-70. [DOI: 10.1002/cmdc.200800087] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
22
|
Mansour TS, Caufield CE, Rasmussen B, Chopra R, Krishnamurthy G, Morris KM, Svenson K, Bard J, Smeltzer C, Naughton S, Antane S, Yang Y, Severin A, Quagliato D, Petersen PJ, Singh G. Naphthyl tetronic acids as multi-target inhibitors of bacterial peptidoglycan biosynthesis. ChemMedChem 2008; 2:1414-7. [PMID: 17600795 DOI: 10.1002/cmdc.200700094] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Tarek S Mansour
- Medicinal Chemistry, Wyeth Research, 401 North Middletown Road, Pearl River, NY 10965, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Discovery and characterization of QPT-1, the progenitor of a new class of bacterial topoisomerase inhibitors. Antimicrob Agents Chemother 2008; 52:2806-12. [PMID: 18519725 DOI: 10.1128/aac.00247-08] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
QPT-1 was discovered in a compound library by high-throughput screening and triage for substances with whole-cell antibacterial activity. This totally synthetic compound is an unusual barbituric acid derivative whose activity resides in the (-)-enantiomer. QPT-1 had activity against a broad spectrum of pathogenic, antibiotic-resistant bacteria, was nontoxic to eukaryotic cells, and showed oral efficacy in a murine infection model, all before any medicinal chemistry optimization. Biochemical and genetic characterization showed that the QPT-1 targets the beta subunit of bacterial type II topoisomerases via a mechanism of inhibition distinct from the mechanisms of fluoroquinolones and novobiocin. Given these attributes, this compound represents a promising new class of antibacterial agents. The success of this reverse genomics effort demonstrates the utility of exploring strategies that are alternatives to target-based screens in antibacterial drug discovery.
Collapse
|
24
|
Barreteau H, Kovac A, Boniface A, Sova M, Gobec S, Blanot D. Cytoplasmic steps of peptidoglycan biosynthesis. FEMS Microbiol Rev 2008; 32:168-207. [PMID: 18266853 DOI: 10.1111/j.1574-6976.2008.00104.x] [Citation(s) in RCA: 479] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The biosynthesis of bacterial cell wall peptidoglycan is a complex process that involves enzyme reactions that take place in the cytoplasm (synthesis of the nucleotide precursors) and on the inner side (synthesis of lipid-linked intermediates) and outer side (polymerization reactions) of the cytoplasmic membrane. This review deals with the cytoplasmic steps of peptidoglycan biosynthesis, which can be divided into four sets of reactions that lead to the syntheses of (1) UDP-N-acetylglucosamine from fructose 6-phosphate, (2) UDP-N-acetylmuramic acid from UDP-N-acetylglucosamine, (3) UDP-N-acetylmuramyl-pentapeptide from UDP-N-acetylmuramic acid and (4) D-glutamic acid and dipeptide D-alanyl-D-alanine. Recent data concerning the different enzymes involved are presented. Moreover, special attention is given to (1) the chemical and enzymatic synthesis of the nucleotide precursor substrates that are not commercially available and (2) the search for specific inhibitors that could act as antibacterial compounds.
Collapse
Affiliation(s)
- Hélène Barreteau
- Laboratoire des Enveloppes Bactériennes et Antibiotiques, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Univ Paris-Sud, Orsay, France
| | | | | | | | | | | |
Collapse
|
25
|
Siegal G, Ab E, Schultz J. Integration of fragment screening and library design. Drug Discov Today 2007; 12:1032-9. [PMID: 18061882 DOI: 10.1016/j.drudis.2007.08.005] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/02/2007] [Accepted: 08/03/2007] [Indexed: 10/22/2022]
Abstract
With more than 10 years of practical experience and theoretical analysis, fragment-based drug discovery (FBDD) has entered the mainstream of the pharmaceutical and biotech industries. An array of biophysical techniques has been used to detect the weak interaction between a fragment and the target. Each technique presents its own requirements regarding the fragment collection and the target; therefore, in order to optimize the potential of FBDD, the nature of the target should be a driving factor for simultaneous development of both the library and the screening technology. A roadmap is now available to guide fragment-to-lead evolution when structural information is available. The next challenge is to apply FBDD to targets for which high-resolution structural information is not available.
Collapse
Affiliation(s)
- Gregg Siegal
- Leiden Institute of Chemistry, Leiden University, The Netherlands.
| | | | | |
Collapse
|
26
|
Lerner CG, Hajduk PJ, Wagner R, Wagenaar FL, Woodall C, Gu YG, Searle XB, Florjancic AS, Zhang T, Clark RF, Cooper CS, Mack JC, Yu L, Cai M, Betz SF, Chovan LE, McCall JO, Black-Schaefer CL, Kakavas SJ, Schurdak ME, Comess KM, Walter KA, Edalji R, Dorwin SA, Smith RA, Hebert EJ, Harlan JE, Metzger RE, Merta PJ, Baranowski JL, Coen ML, Thornewell SJ, Shivakumar AG, Saiki AY, Soni N, Bui M, Balli DJ, Sanders WJ, Nilius AM, Holzman TF, Fesik SW, Beutel BA. From Bacterial Genomes to Novel Antibacterial Agents: Discovery, Characterization, and Antibacterial Activity of Compounds that Bind to HI0065 (YjeE) from Haemophilus influenzae. Chem Biol Drug Des 2007; 69:395-404. [PMID: 17581233 DOI: 10.1111/j.1747-0285.2007.00521.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As part of a fully integrated and comprehensive strategy to discover novel antibacterial agents, NMR- and mass spectrometry-based affinity selection screens were performed to identify compounds that bind to protein targets uniquely found in bacteria and encoded by genes essential for microbial viability. A biphenyl acid lead series emerged from an NMR-based screen with the Haemophilus influenzae protein HI0065, a member of a family of probable ATP-binding proteins found exclusively in eubacteria. The structure-activity relationships developed around the NMR-derived biphenyl acid lead were consistent with on-target antibacterial activity as the Staphylococcus aureus antibacterial activity of the series correlated extremely well with binding affinity to HI0065, while the correlation of binding affinity with B-cell cytotoxicity was relatively poor. Although further studies are needed to conclusively establish the mode of action of the biphenyl series, these compounds represent novel leads that can serve as the basis for the development of novel antibacterial agents that appear to work via an unprecedented mechanism of action. Overall, these results support the genomics-driven hypothesis that targeting bacterial essential gene products that are not present in eukaryotic cells can identify novel antibacterial agents.
Collapse
Affiliation(s)
- Claude G Lerner
- Abbott Global Pharmaceutical Research and Development, Abbott Park, IL 60064-6098, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Comess KM, Schurdak ME, Voorbach MJ, Coen M, Trumbull JD, Yang H, Gao L, Tang H, Cheng X, Lerner CG, McCall JO, Burns DJ, Beutel BA. An Ultraefficient Affinity-Based High-Throughout Screening Process: Application to Bacterial Cell Wall Biosynthesis Enzyme MurF. ACTA ACUST UNITED AC 2006; 11:743-54. [PMID: 16973923 DOI: 10.1177/1087057106289971] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The authors describe the discovery of a new class of inhibitors to an essential Streptococcus pneumoniae cell wall biosyn-thesis enzyme, MurF, by a novel affinity screening method. The strategy involved screening very large mixtures of diverse small organic molecules against the protein target on the basis of equilibrium binding, followed by iterative ultrafiltration steps and ligand identification by mass spectrometry. Hits from any affinity-based screening method often can be relatively nonselective ligands, sometimes referred to as “nuisance” or “promiscuous” compounds. Ligands selective in their binding affinity for the MurF target were readily identified through electronic subtraction of an empirically determined subset of promiscuous compounds in the library without subsequent selectivity panels. The complete strategy for discovery and identification of novel specific ligands can be applied to all soluble protein targets and a wide variety of ligand libraries.
Collapse
Affiliation(s)
- Kenneth M Comess
- Department of Target and Lead Discovery, Global Pharmaceutical R&D, Abbott Laboratories, Abbott Park, Illinois 60064-6217, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|