Matsuo M, Ohtsuka Y, Kataoka K, Mizushima T, Sekimizu K
Department of Microbiology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
J Pharm Pharmacol. 1996 Sep;48(9):985-7. doi: 10.1111/j.2042-7158.1996.tb06018.x.
We examined the influence of fluoroquinolones (norfloxacin, enoxacin, ofloxacin, levofloxacin, and sparfloxacin) on DNA supercoiling of plasmids in Escherichia coli cells by analysis with agarose gel electrophoresis in the presence of chloroquine. All the fluoroquinolones tested immediately induced DNA relaxation. The relaxed DNA was re-supercoiled, and the process was sensitive to chloramphenicol, suggesting that newly synthesized proteins participate in the reaction. The concentrations of fluoroquinolones required for DNA relaxation were much higher than those required for cell killing. The bactericidal effect of fluoroquinolones is apparently related to mechanisms other than DNA relaxation.
我们通过在氯喹存在下用琼脂糖凝胶电泳分析，研究了氟喹诺酮类药物（诺氟沙星、依诺沙星、氧氟沙星、左氧氟沙星和司帕沙星）对大肠杆菌细胞中质粒DNA超螺旋的影响。所有测试的氟喹诺酮类药物都立即诱导DNA松弛。松弛的DNA重新超螺旋化，并且该过程对氯霉素敏感，这表明新合成的蛋白质参与了反应。DNA松弛所需的氟喹诺酮类药物浓度远高于细胞杀伤所需的浓度。氟喹诺酮类药物的杀菌作用显然与DNA松弛以外的机制有关。
