scholarly journals Discovery of Novel DNA Gyrase Inhibitors by High-Throughput Virtual Screening

2007 ◽  
Vol 51 (10) ◽  
pp. 3688-3698 ◽  
Author(s):  
David A. Ostrov ◽  
José A. Hernández Prada ◽  
Patrick E. Corsino ◽  
Kathryn A. Finton ◽  
Nhan Le ◽  
...  
Keyword(s):  
Small Molecules ◽  
Dna Gyrase ◽  
Binding Pocket ◽  
Small Region ◽  
Dna Supercoiling ◽  
Resistant Bacteria ◽  
Topoisomerase Iv ◽  
Antimicrobial Drugs ◽  
Drug Resistant Bacteria ◽  
Gyrase Inhibitors

ABSTRACT The bacterial type II topoisomerases DNA gyrase and topoisomerase IV are validated targets for clinically useful quinolone antimicrobial drugs. A significant limitation to widely utilized quinolone inhibitors is the emergence of drug-resistant bacteria due to an altered DNA gyrase. To address this problem, we have used structure-based molecular docking to identify novel drug-like small molecules that target sites distinct from those targeted by quinolone inhibitors. A chemical ligand database containing approximately 140,000 small molecules (molecular weight, <500) was molecularly docked onto two sites of Escherichia coli DNA gyrase targeting (i) a previously unexplored structural pocket formed at the dimer interface of subunit A and (ii) a small region of the ATP binding pocket on subunit B overlapping the site targeted by coumarin and cyclothialidine drugs. This approach identified several small-molecule compounds that inhibited the DNA supercoiling activity of purified E. coli DNA gyrase. These compounds are structurally unrelated to previously identified gyrase inhibitors and represent potential scaffolds for the optimization of novel antibacterial agents that act on fluoroquinolone-resistant strains.

scholarly journals Experimental and Molecular Docking Studies of Cyclic Diphenyl Phosphonates as DNA Gyrase Inhibitors for Fluoroquinolone-Resistant Pathogens

Antibiotics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Neveen M. Saleh ◽  
Yasmine S. Moemen ◽  
Sara H. Mohamed ◽  
Ghady Fathy ◽  
Abdullah A. S. Ahmed ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Dna Gyrase ◽  
Docking Study ◽  
Dna Supercoiling ◽  
Docking Studies ◽  
Clinical Isolates ◽  
Detectable Effect ◽  
Topoisomerase Iv ◽  
Molecular Docking Studies ◽  
Gyrase Inhibitors

DNA gyrase and topoisomerase IV are proven to be validated targets in the design of novel antibacterial drugs. In this study, we report the antibacterial evaluation and molecular docking studies of previously synthesized two series of cyclic diphenylphosphonates (1a–e and 2a–e) as DNA gyrase inhibitors. The synthesized compounds were screened for their activity (antibacterial and DNA gyrase inhibition) against ciprofloxacin-resistant E.coli and Klebsiella pneumoniae clinical isolates having mutations (deletion and substitution) in QRDR region of DNA gyrase. The target compound (2a) that exhibited the most potent activity against ciprofloxacin Gram-negative clinical isolates was selected to screen its inhibitory activity against DNA gyrase displayed IC50 of 12.03 µM. In addition, a docking study was performed with inhibitor (2a), to illustrate its binding mode in the active site of DNA gyrase and the results were compatible with the observed inhibitory potency. Furthermore, the docking study revealed that the binding of inhibitor (2a) to DNA gyrase is mediated and modulated by divalent Mg2+ at good binding energy (–9.08 Kcal/mol). Moreover, structure-activity relationships (SARs) demonstrated that the combination of hydrazinyl moiety in conjunction with the cyclic diphenylphosphonate based scaffold resulted in an optimized molecule that inhibited the bacterial DNA gyrase by its detectable effect in vitro on gyrase-catalyzed DNA supercoiling activity.

scholarly journals Differential behaviors of Staphylococcus aureus and Escherichia coli type II DNA topoisomerases.

1996 ◽  
Vol 40 (12) ◽  
pp. 2714-2720 ◽  
Author(s):  
F Blanche ◽  
B Cameron ◽  
F X Bernard ◽  
L Maton ◽  
B Manse ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Strong Support ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Type Ii ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Dna Relaxation

Staphylococcus aureus gyrA and gyrB genes encoding DNA gyrase subunits were cloned and coexpressed in Escherichia coli under the control of the T7 promoter-T7 RNA polymerase system, leading to soluble gyrase which was purified to homogeneity. Purified gyrase was catalytically indistinguishable from the gyrase purified from S. aureus and did not contain detectable amounts of topoisomerases from the E. coli host. Topoisomerase IV subunits GrlA and GrlB from S. aureus were also expressed in E. coli and were separately purified to apparent homogeneity. Topoisomerase IV, which was reconstituted by mixing equimolar amounts of GrlA and GrlB, had both ATP-dependent decatenation and DNA relaxation activities in vitro. This enzyme was more sensitive than gyrase to inhibition by typical fluoroquinolone antimicrobial agents such as ciprofloxacin or sparfloxacin, adding strong support to genetic studies which indicate that topoisomerase IV is the primary target of fluoroquinolones in S. aureus. The results obtained with ofloxacin suggest that this fluoroquinolone could also primarily target gyrase. No cleavable complex could be detected with S. aureus gyrase upon incubation with ciprofloxacin or sparfloxacin at concentrations which fully inhibit DNA supercoiling. This suggests that these drugs do not stabilize the open DNA-gyrase complex, at least under standard in vitro incubation conditions, but are more likely to interfere primarily with the DNA breakage step, contrary to what has been reported with E. coli gyrase. Both S. aureus gyrase-catalyzed DNA supercoiling and S. aureus topoisomerase IV-catalyzed decatenation were dramatically stimulated by potassium glutamate or aspartate (500- and 50-fold by 700 and 350 mM glutamate, respectively), whereas topoisomerase IV-dependent DNA relaxation was inhibited 3-fold by 350 mM glutamate. The relevance of the effect of dicarboxylic amino acids on the activities of type II topoisomerases is discussed with regard to the intracellular osmolite composition of S. aureus.

scholarly journals Streptococcus pneumoniae DNA Gyrase and Topoisomerase IV: Overexpression, Purification, and Differential Inhibition by Fluoroquinolones

1999 ◽  
Vol 43 (5) ◽  
pp. 1129-1136 ◽  
Author(s):  
Xiao-Su Pan ◽  
L. Mark Fisher
Keyword(s):  
Streptococcus Pneumoniae ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Topoisomerase Iv ◽  
T7 Promoter ◽  
Bacterial Killing ◽  
E Coli ◽  
Apparent Homogeneity ◽  
Comparable Activity

ABSTRACT Streptococcus pneumoniae gyrA and gyrBgenes specifying the DNA gyrase subunits have been cloned into pET plasmid vectors under the control of an inducible T7 promoter and have been separately expressed in Escherichia coli. Soluble 97-kDa GyrA and 72-kDa GyrB proteins bearing polyhistidine tags at their respective C-terminal and N-terminal ends were purified to apparent homogeneity by one-step nickel chelate column chromatography and were free of host E. coli topoisomerase activity. Equimolar amounts of the gyrase subunits reconstituted ATP-dependent DNA supercoiling with comparable activity to gyrase of E. coli and Staphylococcus aureus. In parallel, S. pneumoniae topoisomerase IV ParC and ParE subunits were similarly expressed in E. coli, purified to near homogeneity as 93- and 73-kDa proteins, and shown to generate efficient ATP-dependent DNA relaxation and DNA decatenation activities. Using the purified enzymes, we examined the inhibitory effects of three paradigm fluoroquinolones—ciprofloxacin, sparfloxacin, and clinafloxacin—which previous genetic studies with S. pneumoniae suggested act preferentially through topoisomerase IV, through gyrase, and through both enzymes, respectively. Surprisingly, all three quinolones were more active in inhibiting purified topoisomerase IV than gyrase, with clinafloxacin showing the greatest inhibitory potency. Moreover, the tested agents were at least 25-fold more effective in stabilizing a cleavable complex (the relevant cytotoxic lesion) with topoisomerase IV than with gyrase, with clinafloxacin some 10- to 32-fold more potent against either enzyme, in line with its superior activity againstS. pneumoniae. The uniform target preference of the three fluoroquinolones for topoisomerase IV in vitro is in apparent contrast to the genetic data. We interpret these results in terms of a model for bacterial killing by quinolones in which cellular factors can modulate the effects of target affinity to determine the cytotoxic pathway.

scholarly journals Nybomycin Inhibits both Fluoroquinolone-Sensitive and Fluoroquinolone-Resistant Escherichia coli DNA Gyrase

2021 ◽  
Vol 65 (5) ◽  
Author(s):  
Dmitrii I. Shiriaev ◽  
Alina A. Sofronova ◽  
Ekaterina A. Berdnikovich ◽  
Dmitrii A. Lukianov ◽  
Ekaterina S. Komarova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Species ◽  
Dna Gyrase ◽  
Resistant Bacteria ◽  
Mutant Form ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type

ABSTRACT Bacterial type II topoisomerases, DNA gyrase and topoisomerase IV, are targets of many antibiotics, including fluoroquinolones (FQs). Unfortunately, a number of bacterial species easily acquire resistance to FQs by mutations in either DNA gyrase or topoisomerase IV genes. The emergence of resistant pathogenic strains is a global problem in health care; therefore, identifying alternative pathways to thwart their persistence is the current frontier in drug discovery. Nybomycins are an attractive class of compounds, reported to be “reverse antibiotics” that selectively inhibit growth of some Gram-positive FQ-resistant bacteria by targeting the mutant form of DNA gyrase while being inactive against wild-type strains with FQ-sensitive gyrases. The strong “reverse” effect was demonstrated only for a few Gram-positive organisms resistant to FQs due to the S83L/I mutation in the GyrA subunit of DNA gyrase. However, the activity of nybomycins has not been extensively explored among Gram-negative species. Here, we observed that in a ΔtolC strain of the Gram-negative Escherichia coli with enhanced permeability, wild-type gyrase and a GyrA S83L mutant, resistant to fluoroquinolones, are similarly sensitive to nybomycin.

scholarly journals Structural and mechanistic analysis of ATPase inhibitors targeting mycobacterial DNA gyrase

2020 ◽  
Vol 75 (10) ◽  
pp. 2835-2842
Author(s):  
Sara R Henderson ◽  
Clare E M Stevenson ◽  
Brandon Malone ◽  
Yelyzaveta Zholnerovych ◽  
Lesley A Mitchenall ◽  
...  
Keyword(s):  
Mycobacterium Smegmatis ◽  
Dna Gyrase ◽  
Binding Pocket ◽  
Dna Supercoiling ◽  
X Ray Crystallography ◽  
Mechanistic Analysis ◽  
Target Dna ◽  
Atpase Inhibitors ◽  
A Site ◽  
Made In

Abstract Objectives To evaluate the efficacy of two novel compounds against mycobacteria and determine the molecular basis of their action on DNA gyrase using structural and mechanistic approaches. Methods Redx03863 and Redx04739 were tested in antibacterial assays, and also against their target, DNA gyrase, using DNA supercoiling and ATPase assays. X-ray crystallography was used to determine the structure of the gyrase B protein ATPase sub-domain from Mycobacterium smegmatis complexed with the aminocoumarin drug novobiocin, and structures of the same domain from Mycobacterium thermoresistibile complexed with novobiocin, and also with Redx03863. Results Both compounds, Redx03863 and Redx04739, were active against selected Gram-positive and Gram-negative species, with Redx03863 being the more potent, and Redx04739 showing selectivity against M. smegmatis. Both compounds were potent inhibitors of the supercoiling and ATPase reactions of DNA gyrase, but did not appreciably affect the ATP-independent relaxation reaction. The structure of Redx03863 bound to the gyrase B protein ATPase sub-domain from M. thermoresistibile shows that it binds at a site adjacent to the ATP- and novobiocin-binding sites. We found that most of the mutations that we made in the Redx03863-binding pocket, based on the structure, rendered gyrase inactive. Conclusions Redx03863 and Redx04739 inhibit gyrase by preventing the binding of ATP. The fact that the Redx03863-binding pocket is distinct from that of novobiocin, coupled with the lack of activity of resistant mutants, suggests that such compounds could have potential to be further exploited as antibiotics.

scholarly journals Structural Maintenance of Chromosomes Protein of Bacillussubtilis Affects Supercoiling In Vivo

2002 ◽  
Vol 184 (19) ◽  
pp. 5317-5322 ◽  
Author(s):  
Janet C. Lindow ◽  
Robert A. Britton ◽  
Alan D. Grossman
Keyword(s):  
Topoisomerase I ◽  
Dna Gyrase ◽  
Dna Supercoiling ◽  
Null Mutant ◽  
Wild Type ◽  
Mutant Plasmid ◽  
Chromatid Cohesion ◽  
Structural Maintenance Of Chromosomes ◽  
Gyrase Inhibitors

ABSTRACT Structural maintenance of chromosomes (SMC) proteins are found in nearly all organisms. Members of this protein family are involved in chromosome condensation and sister chromatid cohesion. Bacillus subtilis SMC protein (BsSMC) plays a role in chromosome organization and partitioning. To better understand the function of BsSMC, we studied the effects of an smc null mutation on DNA supercoiling in vivo. We found that an smc null mutant was hypersensitive to the DNA gyrase inhibitors coumermycin A1 and norfloxacin. Furthermore, depleting cells of topoisomerase I substantially suppressed the partitioning defect of an smc null mutant. Plasmid DNA isolated from an smc null mutant was more negatively supercoiled than that from wild-type cells. In vivo cross-linking experiments indicated that BsSMC was bound to the plasmid. Our results indicate that BsSMC affects supercoiling in vivo, most likely by constraining positive supercoils, an activity which contributes to chromosome compaction and organization.

scholarly journals The Strategies of Pathogen-Oriented Therapy on Circumventing Antimicrobial Resistance

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-32
Author(s):  
Zifang Shang ◽  
Siew Yin Chan ◽  
Qing Song ◽  
Peng Li ◽  
Wei Huang
Keyword(s):  
Antimicrobial Resistance ◽  
Drug Efficacy ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Global Public Health ◽  
Antimicrobial Drugs ◽  
Drug Resistant Bacteria ◽  
New Antibiotics ◽  
Conventional Antibiotics ◽  
Therapeutic Monoclonal Antibodies

The emerging antimicrobial resistance (AMR) poses serious threats to the global public health. Conventional antibiotics have been eclipsed in combating with drug-resistant bacteria. Moreover, the developing and deploying of novel antimicrobial drugs have trudged, as few new antibiotics are being developed over time and even fewer of them can hit the market. Alternative therapeutic strategies to resolve the AMR crisis are urgently required. Pathogen-oriented therapy (POT) springs up as a promising approach in circumventing antibiotic resistance. The tactic underling POT is applying antibacterial compounds or materials directly to infected regions to treat specific bacteria species or strains with goals of improving the drug efficacy and reducing nontargeting and the development of drug resistance. This review exemplifies recent trends in the development of POTs for circumventing AMR, including the adoption of antibiotic-antibiotic conjugates, antimicrobial peptides, therapeutic monoclonal antibodies, nanotechnologies, CRISPR-Cas systems, and microbiota modulations. Employing these alternative approaches alone or in combination shows promising advantages for addressing the growing clinical embarrassment of antibiotics in fighting drug-resistant bacteria.

Moxifloxacin derivatives with potential antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)

2021 ◽  
Vol 21 ◽  
Author(s):  
Rongxing Chen ◽  
Huarui Xue ◽  
Yazhou Xu ◽  
Tianwei Ma ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Drug Resistant ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Methicillin Resistant ◽  
Structure Activity ◽  
Drug Resistant Bacteria ◽  
Mrsa Strains

Background: Methicillin-resistant S. aureus (MRSA) has already tormented humanity and the environment for a long time and is responsible for many difficult-to-treat infections. Unfortunately, there are limited therapeutic options, and MRSA isolates with complete resistance to vancomycin, the first-line drug for the treatment of MRSA infections, have already emerged in recent years. Moxifloxacin retained activity against mutant bacterial strains with various levels of fluoroquinolones resistance and had a lower potential to select for resistant mutants. Isatin is a versatile structure, and its derivatives are potent inhibitors of many enzymes and receptors. The fluoroquinolone-isatin derivatives demonstrated excellent antibacterial activity against both drug-sensitive and drug-resistant organisms. The structure-activity relationship elucidated that incorporation of 1,2,3-triazole moiety into the C-7 position of fluoroquinolone skeleton was favorable to the antibacterial activity. Accordingly, fluoroquinolone derivatives with isatin and 1,2,3-triazole fragments at the side chain on the C-7 position are promising candidates to fight against drug-resistant bacteria. Objective: To explore more active moxifloxacin derivatives to fight against MRSA and enrich the structure-activity relationships. Methods: The synthesized moxifloxacin derivatives 7a-i and 14a-f were evaluated for their antibacterial activity against a panel of MRSA strains by means of standard two-fold serial dilution method. Results: The majority of the synthesized moxifloxacin derivatives were active against most of the tested MRSA strains with MIC values in a range of 1 to 64 μg/mL. The mechanistic investigations revealed that topoisomerase IV was one of the targets for antibacterial activity. Conclusion: These derivatives are useful scaffolds for the development of novel topoisomerase IV inhibitors.

HAMP: A Knowledgebase of Antimicrobial Peptides from Human Microbiome.

2020 ◽  
Vol 15 ◽  
Author(s):  
Viswajit Mulpuru ◽  
Rahul Semwal ◽  
Pritish Kumar Varadwaj ◽  
Nidhi Mishra
Keyword(s):  
Antimicrobial Peptides ◽  
Human Microbiome ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antimicrobial Drugs ◽  
Candidate Peptide ◽  
Drug Resistant Bacteria ◽  
Query Engine ◽  
Extended Analysis ◽  
Drug Resistant Strains

Background: Antimicrobial peptides (AMPs) can defend the hosts against various pathogens and are found in almost every life form from microorganisms to humans. As the rapid increase of drug-resistant strains in recent years is presenting a serious challenge to healthcare, antimicrobial peptides (AMPs) can revolutionize the antimicrobial development against the drug-resistant microbes. Objective: The objective was to encourage the study on the human microbiome towards inhibition of drug-resistant bacteria by the development of a database containing antimicrobial peptides from the human microbiome. Method: This database is an outcome of an extended analysis of Human metagenome, involving the prediction of coding regions, extraction of peptides, prediction of antimicrobial peptides, and modeling their structure utilizing different in silico tools. Further, an intelligent hash function-based query engine was designed to validate the novelty of specific candidate peptide over the reported knowledgebase. Result and Discussion: This knowledgebase currently focuses on antimicrobial peptide sequences (AMPs) predicted from the human microbiome along with 3D their structures modeled using various modeling and molecular dynamics approaches. It includes a total of 1087 unique AMPs from various body sites, with 454 AMPs from the oral cavity, 180 AMPs from the gastrointestinal tract, 42 AMPs from the skin, 12 AMPs from the airway, 6 AMPs from the urogenital tract and 393 AMPs from undefined body locations. A scoring matrix has been generated based on the similarity scores of the sequences that have been incorporated into the knowledgebase. Further, a Jmol applet is included in the website to help users visualize the 3D structures. Conclusion: The information and functions of the knowledgebase can offer great help in finding novel antimicrobial drugs, especially towards finding inhibitors for drug-resistant bacteria. The HAMP is freely available at https://bioserver.iiita.ac.in/amp/index.html.

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