Open AccessIn vitro cleavable-complex assay to monitor antimicrobial potency of quinolones
Author(s) -
Leslie Walton,
Lynn P. Elwell
Publication year - 1988
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.32.7.1086
Subject(s) - dna gyrase , dna supercoil , escherichia coli , dna , biology , biochemistry , in vitro , potency , chemistry , dna replication , gene
Seven quinolones were evaluated to determine whether their ability to generate the DNA gyrase-mediated cleavable complex correlated with their ability to inhibit the catalytic activity of purified DNA gyrase and inhibit the growth of Escherichia coli. The rank order of potency of these drugs in the cleavable-complex assay was essentially the same as in the DNA supercoiling-inhibition assay. It required 2- to 10-fold-lower drug concentrations to generate the cleavable complex than to inhibit E. coli DNA gyrase. With the newer fluoroquinolones, a 25- to 100-fold-greater concentration was required for DNA gyrase inhibition than for cell growth inhibition, suggesting a more subtle interaction between these inhibitors and DNA gyrase than mere enzyme inhibition.