Fig. 6.
Effects of ciprofloxacin- and moxifloxacin-based fluoroquinolones on DNA cleavage mediated by WT and mutant M. tuberculosis gyrase and human topoisomerase IIα. The ability of WT (Top Left), GyrAA90V (A90V, Top Right), and GyrAD94G (D94G, Bottom Left) gyrase and human topoisomerase IIα (hTIIα, Bottom Right) to cleave DNA in the presence of fluoroquinolones containing a C8-H (black), -methyl (blue), or -methoxy (red) group and a C7 piperazinyl (closed symbols) or diazabicyclononyl (open symbols) group is shown. For human topoisomerase IIα, DNA cleavage levels induced by the enzyme in the presence of CP-115,955 or etoposide (dashed lines) are shown for comparison. These latter data are from Aldred et al. (32). The ciprofloxacin and moxifloxacin fluoroquinolone cores are shown at the top. Error bars represent the SD of at least three independent experiments.