Action of quinolones against Staphylococcus aureus topoisomerase IV:: Basis for DNA cleavage enhancement
Action of quinolones against Staphylococcus aureus topoisomerase IV:: Basis for DNA cleavage enhancement
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DOI：
10.1021/bi992302n
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发表时间：
2000-03-14
期刊：
影响因子：
2.9
通讯作者：
Osheroff, N
中科院分区：
文献类型：
--
作者：
Anderson, VE;Zaniewski, RP;Osheroff, N
拓扑异构酶IV是革兰氏阳性细菌中大多数喹诺酮类药物的主要细胞靶点；因此，我们研究了临床上常用的四种抗菌喹诺酮类药物（环丙沙星，以及三种新一代喹诺酮类药物：曲瓦沙星、左氧氟沙星和斯帕沙星）对金黄色葡萄球菌拓扑异构酶IV的DNA切割/还原反应的影响。这些喹诺酮类药物刺激酶介导的DNA断裂的程度相似，但它们的效力差异很大。在不含ATP的情况下，药物顺序为：曲瓦沙星>环丙沙星>左氧氟沙星>斯帕沙星，ATP可增强药物效力，但每种药物的效力增强程度不同。在所有检查条件下，曲瓦沙星是最有效的喹诺酮类药物，斯帕沙星是最不有效的。曲瓦沙星的效力增强与若干性质相关。与其他喹诺酮类药物相比，曲瓦沙星能更快地诱导拓扑异构酶iv介导的DNA断裂，并在某些位点产生更多的裂解。然而，喹诺酮类药物的效力与酶介导的DNA抑制之间存在最显著的相关性：效力越大，抑制作用越强。对两种具有喹诺酮类药物临床耐药性的拓扑异构酶IV突变体（GrlA（Ser80Phe）和GrlA(Glu84Lys)）进行的剂量反应实验表明，耐药性是由药物亲和力和疗效的降低引起的。曲瓦沙星比环丙沙星对这些酶更有活性，因为它部分地克服了对亲和力的影响。最后，DNA切割和十烯二甲基化的比较研究表明，曲瓦沙星的抗菌特性是由于金黄色葡萄球菌拓扑异构酶iv介导的DNA切割增加，而不是抑制酶催化。
Topoisomerase IV is the primary cellular target for most quinolones in Gram-positive bacteria; however, its interaction with these agents is pearly understood, Therefore, the effects of four clinically relevant antibacterial quinolones (ciprofloxacin, and three new generation quinolones: trovafloxacin, levofloxacin, and sparfloxacin) on the DNA cleavage/religation reaction of Staphylococcus aureus topoisomerase IV were characterized. These quinolones stimulated enzyme-mediated DNA scission to a similar extent, but their potencies varied significantly. Drug order in the absence of ATP was trovafloxacin > ciprofloxacin > levofloxacin > sparfloxacin, Potency was enhanced by ATP, but to a different extent for each drug. Under all conditions examined, trovafloxacin was the most potent quinolone and sparfloxacin was the least. The enhanced potency of trovafloxacin correlated with several properties. Trovafloxacin induced topoisomerase IV-mediated DNA scission more rapidly than other quinolones and generated more cleavage at some sites. The most striking correlation, however, was between quinolone potency and inhibition of enzyme-mediated DNA religation: the greater the potency, the stronger the inhibition, Dose-response experiments with two topoisomerase IV mutants that confer clinical resistance to quinolones (GrlA(Ser80Phe) and GrlA(Glu84Lys)) indicate that resistance is caused by a decrease in both drug affinity and efficacy. Trovafloxacin is more active against these enzymes than ciprofloxacin because it partially overcomes the effect on affinity. Finally, comparative studies on DNA cleavage and decatenation suggest that the antibacterial properties of trovafloxacin result from increased S. aureus topoisomerase IV-mediated DNA cleavage rather than inhibition of enzyme catalysis.