State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, P. R. China.
Bioassay Research Department, Central Agricultural Pesticide Laboratory, Agricultural Research Center, Dokki, Giza, Egypt.
Pest Manag Sci. 2021 Jun;77(6):2737-2746. doi: 10.1002/ps.6302. Epub 2021 Feb 22.
Carboxyl/cholinesterases (CCEs) are thought to play a pivotal role in the degradation of sex pheromones and plant-derived odorants in insects, but their exact biochemistry and physiological functions remain unclear.
In this study, two paralogous antennae-enriched CCEs from Plutella xylostella (PxylCCE16a and 16c) were identified and functionally characterized. High-purity protein preparations of active recombinant PxylCCE16a and 16c have been obtained from Sf9 insect cells by Ni affinity purification. Our results revealed that the purified recombinant PxylCCE016c is able to degrade two sex pheromone components Z9-14:Ac and Z11-16:Ac at 27.64 ± 0.79% and 24.40 ± 3.07%, respectively, while PxylCCE016a presented relatively lower activity. Additionally, a similar difference in activity was measured in plant-derived odorants. Furthermore, both CCEs displayed obvious preferences for the two sex pheromone components, especially on Z11-16:Ac (K values are in the range 7.82-45.06 μmol L ) which much lower than plant odorants (K values are in the range 1290-4030 μmol L ). Furthermore, the activity of the two newly identified CCEs is pH-dependent. The activity at pH 6.5 is obviously higher than that at pH 5.0. Interestingly, only PxylCCE016c can be inhibited by a common esterase inhibitor triphenyl phosphate (TPP) with LC of 1570 ± 520 μmol L .
PxylCCE16c plays a more essential role in odorant degradation than PxylCCE16a. Moreover, the current study provides novel potential pesticide targets for the notorious moth Plutella xylostella. © 2021 Society of Chemical Industry.
羧酸酯酶/胆碱酯酶（CCEs）被认为在昆虫中降解性信息素和植物源气味物质中发挥关键作用，但它们的确切生化和生理功能仍不清楚。
本研究从小菜蛾（Plutella xylostella）中鉴定出两个功能相似的触角富含 CCE（PxylCCE16a 和 16c），并对其进行了功能表征。通过 Ni 亲和纯化从 Sf9 昆虫细胞中获得了高纯度的活性重组 PxylCCE16a 和 16c 蛋白制剂。结果表明，纯化的重组 PxylCCE016c 能够分别以 27.64±0.79%和 24.40±3.07%的速率降解两种性信息素成分 Z9-14：Ac 和 Z11-16：Ac，而 PxylCCE016a 的活性相对较低。此外，在植物源气味物质中也测量到类似的活性差异。此外，两种 CCE 对两种性信息素成分均表现出明显的偏好，尤其是 Z11-16：Ac（K 值在 7.82-45.06 μmol/L 范围内），远低于植物气味物质（K 值在 1290-4030 μmol/L 范围内）。此外，两种新鉴定的 CCE 的活性均依赖于 pH。pH 6.5 时的活性明显高于 pH 5.0 时的活性。有趣的是，只有 PxylCCE016c 可以被常见的酯酶抑制剂三苯基膦（TPP）抑制，LC 为 1570±520 μmol/L。
PxylCCE16c 在气味物质降解中比 PxylCCE16a 发挥更重要的作用。此外，本研究为臭名昭著的小菜蛾提供了新的潜在农药靶标。© 2021 化学工业协会。
