scholarly journals Hybrid Inhibitors of DNA Gyrase A and B: Design, Synthesis and Evaluation

Pharmaceutics ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 6
Author(s):  
Martina Durcik ◽  
Žiga Skok ◽  
Janez Ilaš ◽  
Nace Zidar ◽  
Anamarija Zega ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Design Synthesis ◽  
Bacterial Dna ◽  
E Coli ◽  
Catalytic Inhibitor ◽  
Catalytic Sites ◽  
Competitive Inhibitors ◽  
Gyrase A

The discovery of multi-targeting ligands of bacterial enzymes is an important strategy to combat rapidly spreading antimicrobial resistance. Bacterial DNA gyrase and topoisomerase IV are validated targets for the development of antibiotics. They can be inhibited at their catalytic sites or at their ATP binding sites. Here we present the design of new hybrids between the catalytic inhibitor ciprofloxacin and ATP-competitive inhibitors that show low nanomolar inhibition of DNA gyrase and antibacterial activity against Gram-negative pathogens. The most potent hybrid 3a has MICs of 0.5 µg/mL against Klebsiella pneumoniae, 4 µg/mL against Enterobacter cloacae, and 2 µg/mL against Escherichia coli. In addition, inhibition of mutant E. coli strains shows that these hybrid inhibitors interact with both subunits of DNA gyrase (GyrA, GyrB), and that binding to both of these sites contributes to their antibacterial activity.

scholarly journals Design, Synthesis, and Antibacterial Screening of Some Novel Heteroaryl-Based Ciprofloxacin Derivatives as DNA Gyrase and Topoisomerase IV Inhibitors

2021 ◽  
Vol 14 (5) ◽  
pp. 399
Author(s):  
Lamya H. Al-Wahaibi ◽  
Amer A. Amer ◽  
Adel A. Marzouk ◽  
Hesham A.M. Gomaa ◽  
Bahaa G. M. Youssif ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Dna Gyrase ◽  
Bacterial Strains ◽  
Topoisomerase Iv ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Antibacterial Screening ◽  
Ic50 Values

A novel series of ciprofloxacin hybrids comprising various heterocycle derivatives has been synthesized and structurally elucidated using 1H NMR, 13C NMR, and elementary analyses. Using ciprofloxacin as a reference, compounds 1–21 were screened in vitro against Gram-positive bacterial strains such as Staphylococcus aureus and Bacillus subtilis and Gram-negative strains such as Escherichia coli and Pseudomonas aeruginosa. As a result, many of the compounds examined had antibacterial activity equivalent to ciprofloxacin against test bacteria. Compounds 2–6, oxadiazole derivatives, were found to have antibacterial activity that was 88 to 120% that of ciprofloxacin against Gram-positive and Gram-negative bacteria. The findings showed that none of the compounds tested had antifungal activity against Aspergillus flavus, but did have poor activity against Candida albicans, ranging from 23% to 33% of fluconazole, with compound 3 being the most active (33% of fluconazole). The most potent compounds, 3, 4, 5, and 6, displayed an IC50 of 86, 42, 92, and 180 nM against E. coli DNA gyrase, respectively (novobiocin, IC50 = 170 nM). Compounds 4, 5, and 6 showed IC50 values (1.47, 6.80, and 8.92 µM, respectively) against E. coli topo IV in comparison to novobiocin (IC50 = 11 µM).

New dual ATP-competitive inhibitors of bacterial DNA gyrase and topoisomerase IV active against ESKAPE pathogens

2021 ◽  
Vol 213 ◽  
pp. 113200
Author(s):  
Martina Durcik ◽  
Ákos Nyerges ◽  
Žiga Skok ◽  
Darja Gramec Skledar ◽  
Jurij Trontelj ◽  
...  
Keyword(s):  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Bacterial Dna ◽  
Competitive Inhibitors ◽  
Eskape Pathogens

scholarly journals Role of the Extended α4 Domain of Staphylococcus aureus Gyrase A Protein in Determining Low Sensitivity to Quinolones

2006 ◽  
Vol 50 (2) ◽  
pp. 600-606 ◽  
Author(s):  
Jacob Strahilevitz ◽  
Ari Robicsek ◽  
David C. Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Acquired Resistance ◽  
Dna Gyrase ◽  
Wild Type ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Gyrase A ◽  
Low Sensitivity ◽  
Emergence Of Resistance

ABSTRACT Fluoroquinolones target two bacterial type II topoisomerases, DNA gyrase and topoisomerase IV. Acquired resistance to quinolones occurs stepwise, with the first mutation occurring in the more sensitive target enzyme. To limit the emergence of resistance, quinolones should ideally possess dual activities against the two enzymes. For reasons that are as yet unclear, Staphylococcus aureus gyrase is less sensitive to quinolones than topoisomerase IV, counter to its greater sensitivity in Escherichia coli, thereby limiting the use of quinolones for the treatment of staphylococcal infections. Mutations in the α4-helix domain of the GyrA subunit of gyrase are important in determining quinolone resistance. We replaced an extended region encompassing the α4 domain in the E. coli GyrA protein with its homolog in S. aureus and tested for its ability to complement a thermosensitive gyrase and its catalytic and noncatalytic properties. Purified gyrase reconstituted with chimeric GyrA was more resistant to ciprofloxacin than wild-type gyrase at both inhibition of catalytic activity and stimulation of cleavage complexes, and this difference was more apparent in the presence of K+-glutamate. The chimeric GyrA subunit was able to complement thermosensitive gyrase, similar to wild-type GyrA. Without supplemental K+-glutamate the MICs of ciprofloxacin for thermosensitive E. coli complemented with chimeric DNA gyrase were equal to those for E. coli complemented with wild-type gyrase but were twofold higher in the presence of K+-glutamate. Our findings suggest that the extended α4 domain of S. aureus GyrA is responsible, at least in part, for the increased resistance of S. aureus gyrase to quinolones and that this effect is modulated by K+-glutamate.

scholarly journals In VitroandIn VivoCharacterization of the Novel Oxabicyclooctane-Linked Bacterial Topoisomerase Inhibitor AM-8722, a Selective, Potent Inhibitor of Bacterial DNA Gyrase

2016 ◽  
Vol 60 (8) ◽  
pp. 4830-4839 ◽  
Author(s):  
Christopher M. Tan ◽  
Charles J. Gill ◽  
Jin Wu ◽  
Nathalie Toussaint ◽  
Jingjun Yin ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Antibacterial Agents ◽  
Cell Activity ◽  
Dna Gyrase ◽  
Topoisomerase Iv ◽  
Bacterial Dna ◽  
Whole Cell ◽  
Content Type

ABSTRACTOxabicyclooctane-linked novel bacterial topoisomerase inhibitors (NBTIs) represent a new class of recently described antibacterial agents with broad-spectrum activity. NBTIs dually inhibit the clinically validated bacterial targets DNA gyrase and topoisomerase IV and have been shown to bind distinctly from known classes of antibacterial agents directed against these targets. Herein we report the molecular, cellular, andin vivocharacterization of AM-8722 as a representative N-alkylated-1,5-naphthyridone left-hand-side-substituted NBTI. Consistent with its mode of action, macromolecular labeling studies revealed a specific effect of AM-8722 to dose dependently inhibit bacterial DNA synthesis. AM-8722 displayed greater intrinsic enzymatic potency than levofloxacin versus both DNA gyrase and topoisomerase IV fromStaphylococcus aureusandEscherichia coliand displayed selectivity against human topoisomerase II. AM-8722 was rapidly bactericidal and exhibited whole-cell activity versus a range of Gram-negative and Gram-positive organisms, with no whole-cell potency shift due to the presence of DNA or human serum. Frequency-of-resistance studies demonstrated an acceptable rate of resistance emergencein vitroat concentrations 16- to 32-fold the MIC. AM-8722 displayed acceptable pharmacokinetic properties and was shown to be efficacious in mouse models of bacterial septicemia. Overall, AM-8722 is a selective and potent NBTI that displays broad-spectrum antimicrobial activityin vitroandin vivo.

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 Quinolone-resistant mutants of escherichia coli DNA topoisomerase IV parC gene.

1996 ◽  
Vol 40 (3) ◽  
pp. 710-714 ◽  
Author(s):  
Y Kumagai ◽  
J I Kato ◽  
K Hoshino ◽  
T Akasaka ◽  
K Sato ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Gyrase ◽  
Mutant Gene ◽  
Missense Mutations ◽  
Topoisomerase Iv ◽  
Dna Topoisomerase ◽  
E Coli ◽  
A Subunit ◽  
Resistant Strains ◽  
Mutant Genes

Escherichia coli quinolone-resistant strains with mutations of the parC gene, which codes for a subunit of topoisomerase IV, were isolated from a quinolone-resistant gyrA mutant of DNA gyrase. Quinolone-resistant parC mutants were also identified among the quinolone-resistant clinical strains. The parC mutants became susceptible to quinolones by introduction of a parC+ plasmid. Introduction of the multicopy plasmids carrying the quinolone-resistant parC mutant gene resulted in an increase in MICs of quinolones for the parC+ and quinolone-resistant gyrA strain. Nucleotide sequences of the quinolone-resistant parC mutant genes were determined, and missense mutations at position Gly-78, Ser-80, or Glu-84, corresponding to those in the quinolone-resistance-determining region of DNA gyrase, were identified. These results indicate that topoisomerase IV is a target of quinolones in E. coli and suggest that the susceptibility of E. coli cells to quinolones is determined by sensitivity of the targets, DNA gyrase and topoisomerase IV.

scholarly journals Inhibitory Activities of Gatifloxacin (AM-1155), a Newly Developed Fluoroquinolone, against Bacterial and Mammalian Type II Topoisomerases

1998 ◽  
Vol 42 (10) ◽  
pp. 2678-2681 ◽  
Author(s):  
Masaya Takei ◽  
Hideyuki Fukuda ◽  
Tokutaro Yasue ◽  
Masaki Hosaka ◽  
Yasuo Oomori
Keyword(s):  
Hela Cell ◽  
Topoisomerase Ii ◽  
Dna Gyrase ◽  
Antibacterial Activities ◽  
Type Ii ◽  
Topoisomerase Iv ◽  
E Coli ◽  
Bacterial Enzyme ◽  
Inhibitory Activities ◽  
Bacterial Type

ABSTRACT We determined the inhibitory activities of gatifloxacin againstStaphylococcus aureus topoisomerase IV,Escherichia coli DNA gyrase, and HeLa cell topoisomerase II and compared them with those of several quinolones. The inhibitory activities of quinolones against these type II topoisomerases significantly correlated with their antibacterial activities or cytotoxicities (correlation coefficient [r] = 0.926 forS. aureus, r = 0.972 for E. coli, and r = 0.648 for HeLa cells). Gatifloxacin possessed potent inhibitory activities against bacterial type II topoisomerases (50% inhibitory concentration [IC50] = 13.8 μg/ml for S. aureustopoisomerase IV; IC50 = 0.109 μg/ml for E. coli DNA gyrase) but the lowest activity against HeLa cell topoisomerase II (IC50 = 265 μg/ml) among the quinolones tested. There was also a significant correlation between the inhibitory activities of quinolones against S. aureustopoisomerase IV and those against E. coli DNA gyrase (r = 0.969). However, the inhibitory activity against HeLa cell topoisomerase II did not correlate with that against either bacterial enzyme. The IC50 of gatifloxacin for HeLa cell topoisomerase II was 19 and was more than 2,400 times higher than that for S. aureus topoisomerase IV and that for E. coli DNA gyrase. These ratios were higher than those for other quinolones, indicating that gatifloxacin possesses a higher selectivity for bacterial type II topoisomerases.

scholarly journals Design, Synthesis and Antibacterial Activity of Coumarin-1,2,3-triazole Hybrids Obtained from Natural Furocoumarin Peucedanin

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2126 ◽  
Author(s):  
Alla V. Lipeeva ◽  
Danila O. Zakharov ◽  
Liubov G. Burova ◽  
Tatyana S. Frolova ◽  
Dmitry S. Baev ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Cycloaddition Reaction ◽  
Bacterial Strains ◽  
Design Synthesis ◽  
Docking Simulations ◽  
E Coli ◽  
Antibiotic Drugs ◽  
In Vitro Antibacterial Activity ◽  
Substituted Coumarins

Synthesis of 1,2,3-triazole-substituted coumarins and also 1,2,3-triazolyl or 1,2,3-triazolylalk-1-inyl-linked coumarin-2,3-furocoumarin hybrids was performed by employing the cross-coupling and copper catalyzed azide-alkyne cycloaddition reaction approaches. The synthesized compounds were evaluated for their in vitro antibacterial activity against Staphylococcus aureus, Bacillius subtilis, Actinomyces viscosus and Escherichia coli bacterial strains. Coumarin-benzoic acid hybrids 4с, 42с and 3-((4-acetylamino-3-(methoxycarbonyl)phenyl)ethynyl)coumarin (29) showed promising activity against S. aureus strains, and the 1,2,3-triazolyloct-1-inyl linked coumarin-2,3-furocoumarin hybrid 37c was endowed with high selectivity against B. subtilis and E. coli species. The in vitro antibacterial activity of 4с, 29, 37c and 42с can potentially be compared with that of a number of modern antibiotic drugs used in the clinic, suggesting promising prospects for further research. A detailed study of the molecular interactions with the targeted protein MurB was performed using docking simulations and the obtained results are quite promising.

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