Substitutions in Spodoptera exigua topoisomerase I modulate its relaxation activity and camptothecin sensitivity
Substitutions in Spodoptera exigua topoisomerase I modulate its relaxation activity and camptothecin sensitivity
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甜菜夜蛾拓扑异构酶 I 的取代可调节其松弛活性和喜树碱敏感性
DOI：
10.1002/ps.4440
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发表时间：
2017
影响因子：
4.1
通讯作者：
Jiang Hongyun
中科院分区：
文献类型：
--
作者：
Zhang Pei;Zhang Lan;Zhang Yanning;Mao Liangang;Jiang Hongyun
拓扑异构酶I（TopI）是喜树碱（CPTs）的细胞靶点，而CPTs正被开发为潜在的昆虫防治农药。我们在前期的研究中发现了昆虫TopIs基因的三个氨基酸替换，包括L530P、A653T和S729T。为了研究这三个取代的效果，对野生型和突变体Top I在Spodoptera exiguaHübner. TS中进行了比较分析。A653T和S729T的最佳盐浓度为150 mM，这与野生型Top I的最佳盐浓度一致，而突变体L530 P在较低的KCl浓度（100 mM）下显示出最大的松弛活性。突变的L530P和A653T Top Is由于对负超螺旋质粒pBR 322 DNA的松弛速度增加而显示出更高的松弛效率，这使得L530P和A653T对CPT具有抗性，而突变体S729T对CPTs敏感，这是由于对质粒pBR 322 DNA的松弛活性降低。结果表明，CPTs的生物活性与害虫的生长发育有关，为合理使用CPTs防治害虫提供了基础资料。© 2016化学工业协会
BACKGROUNDTopoisomerase I (Top I) is referred as the cellular target of the camptothecins (CPTs) which are now being explored as potential pesticides for insect control. Three amino acid substitutions, including L530P, A653T and S729T, in Top Is of insects were found in our previous studies. In order to investigate the effect of these three substitutions, a comparative analysis was conducted between the wild‐type and mutant Top Is inSpodoptera exiguaHübner.RESULTSThe optimal salt concentration of A653T and S729T was 150 mm, which is consistent with that of the wild‐type Top I, while the mutant L530P showed maximum relaxation activity at a lower KCl concentration (100 mm). The mutated L530P and A653T Top Is showed a higher relaxation efficiency owing to an increased relaxation velocity toward the negatively supercoiled plasmid pBR322 DNA, which rendered L530P and A653T resistant to CPTs, whereas mutant S729T exhibited sensitivity to CPTs as a result of a decreased relaxation activity toward plasmid pBR322 DNA.CONCLUSIONSThese results suggested that the polymorphism in Top I of insects was related to the biological activity of CPTs, which provided the basic information for reasonable usage of CPTs to control insect pests. © 2016 Society of Chemical Industry