Interaction of N-methyl-2-alkenyl-4-quinolones with ATP-dependent MurE ligase of Mycobacterium tuberculosis: antibacterial activity, molecular docking and inhibition kinetics

• Published in: Journal of antimicrobial chemotherapy Vol. 66; no. 8; pp. 1766 - 1772
• Main Authors: Guzman, Juan David, Wube, Abraham, Evangelopoulos, Dimitrios, Gupta, Antima, Hüfner, Antje, Basavannacharya, Chandrakala, Rahman, Md. Mukhleshur, Thomaschitz, Christina, Bauer, Rudolf, McHugh, Timothy Daniel, Nobeli, Irene, Prieto, Jose M., Gibbons, Simon, Bucar, Franz, Bhakta, Sanjib
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.08.2011; Oxford Publishing Limited (England)
• Subjects: 4-Quinolones - chemistry; 4-Quinolones - metabolism; Adenosine triphosphatase; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - metabolism; Antibiotics; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacterial diseases; Bacterial Proteins - antagonists & inhibitors; Bacterial Proteins - metabolism; Binding sites; Biological and medical sciences; Drug resistance; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - growth & development; Gram-positive bacteria; Human bacterial diseases; Humans; Infectious diseases; Medical sciences; Microbial Sensitivity Tests; Models, Molecular; Molecular Dynamics Simulation; Mycobacterium - drug effects; Mycobacterium - enzymology; Mycobacterium - growth & development; Mycobacterium bovis; Mycobacterium fortuitum; Mycobacterium phlei; Mycobacterium smegmatis; Mycobacterium tuberculosis; Original Research; Peptide Synthases - antagonists & inhibitors; Peptide Synthases - metabolism; Pharmacology. Drug treatments; Protein Binding; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - growth & development; Staphylococcus aureus; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Mur ligase inhibitors; 4-quinolones; Enzyme; Interaction; Mycobacterial infection; M. tuberculosis; Infection; Tuberculosis; Mycobacterium tuberculosis; Mycobacteriales; Ligases; Bacteriosis; Mycobacteriaceae; Bacteria; Actinomycetes; Inhibitor; Kinetics; Inhibition; Antibacterial agent; ATP; Quinolone derivatives
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkr203

Objectives The aim of this study was to comprehensively evaluate the antibacterial activity and MurE inhibition of a set of N-methyl-2-alkenyl-4-quinolones found to inhibit the growth of fast-growing mycobacteria. Methods Using the spot culture growth inhibition assay, MICs were determined for Mycobacterium tuberculosis H37Rv, Mycobacterium bovis BCG and Mycobacterium smegmatis mc2155. MICs were determined for Mycobacterium fortuitum, Mycobacterium phlei, methicillin-resistant Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa using microplate dilution assays. Inhibition of M. tuberculosis MurE ligase activity was determined both by colorimetric and HPLC methods. Computational modelling and binding prediction of the quinolones in the MurE structure was performed using Glide. Kinetic experiments were conducted for understanding possible competitive relations of the quinolones with the endogenous substrates of MurE ligase. Results The novel synthetic N-methyl-2-alkenyl-4-quinolones were found to be growth inhibitors of M. tuberculosis and rapid-growing mycobacteria as well as methicillin-resistant S. aureus, while showing no inhibition for E. coli and P. aeruginosa. The quinolones were found to be inhibitory to MurE ligase of M. tuberculosis in the micromolar range (IC50 ∼40-200 μM) when assayed either spectroscopically or by HPLC. Computational docking of the quinolones on the published M. tuberculosis MurE crystal structure suggested that the uracil recognition site is a probable binding site for the quinolones. Conclusions N-methyl-2-alkenyl-4-quinolones are inhibitors of mycobacterial and staphylococcal growth, and show MurE ligase inhibition. Therefore, they are considered as a starting point for the development of increased affinity MurE activity disruptors.