College of Plant Protection, Northwest A&F University, Yangling 712100, China.
Shandong Institute for Product Quality Inspection, Jinan 250102, China.
Toxins (Basel). 2017 Dec 6;9(12):393. doi: 10.3390/toxins9120393.
Celangulin V (CV) is the main insecticidal constituent of . The V-ATPase H subunit of the midgut cells of lepidopteran larvae is the putative target protein of CV. Here, we compared the effects of CV on the midgut membrane potentials of and larvae with those of the Cry1Ab toxin from and with those of inactive CV-MIA, a synthetic derivative of CV. We investigated the changes in the apical membrane potentials () and basolateral membrane potentials () of the midguts of sixth-instar larvae force-fed with the test toxins. We also measured the and of larval midguts that were directly incubated with the test toxins. Similar to the effect of Cry1Ab, the of CV-treated midguts rapidly decayed over time in a dose-dependent manner. By contrast, CV-MIA did not influence . Meanwhile, the of larval midguts directly incubated with CV decayed less than that of larval midguts, whereas that of larvae force-fed with CV did not significantly change. Similar to Cry1Ab, CV did not affect the of isolated midguts. CV significantly inhibited V-ATPase activity in a dose-dependent manner. Therefore, CV initially inhibits V-ATPase in the apical membrane and affects intracellular pH, homeostasis, and nutrient transport mechanisms in lepidopteran midgut cells.
Celangulin V (CV) 是 的主要杀虫成分。鳞翅目幼虫中肠细胞的 V-ATPase H 亚基是 CV 的假定靶标蛋白。在这里，我们比较了 CV 对 和 幼虫中肠膜电位的影响，以及来自 和无活性 CV-MIA（CV 的合成衍生物）的 Cry1Ab 毒素的影响。我们研究了用测试毒素强迫喂食的 6 龄幼虫的顶膜电位 () 和基底外侧膜电位 () 的变化。我们还测量了直接与测试毒素孵育的幼虫中肠的 和 。类似于 Cry1Ab 的作用，CV 处理的中肠的 随时间呈剂量依赖性迅速衰减。相比之下，CV-MIA 不影响 。同时，与 幼虫中肠相比，直接用 CV 孵育的 幼虫中肠的 衰减较小，而用 CV 强迫喂食的幼虫中肠的 没有明显变化。类似于 Cry1Ab，CV 不影响分离的中肠的 。CV 以剂量依赖性方式显著抑制 V-ATPase 活性。因此，CV 最初抑制了鳞翅目中肠细胞的顶端膜中的 V-ATPase，并影响了细胞内 pH 值、稳态和营养物质运输机制。
