Identification of key residues of carboxylesterase PxEst-6 involved in pyrethroid metabolism in Plutella xylostella (L.)

論文信息：Identification of key residues of carboxylesterase PxEst-6 involved in pyrethroid metabolism in  Plutella xylostella (L.). Yifan Li, ^# Hong Sun, ^# Zhen Tian, ^# Yue Li, Xuan Ye, Ruichi Li,Xinyu Li,Shengli Zheng, Jiyuan Liu, ^* Yalin Zhang, ^*  Journal of Hazardous Materials .407 (2021) 124612.

JCR分區(qū)Q1，中科院大類(lèi)一區(qū)，IF= 9.038，TOP期刊

論文摘要：

The long-term and excessive use of insecticides has led to severe environmental problems and the evolution of insecticide resistance in insects. Carboxylesterases (CarEs) are important detoxification enzymes conferring insecticide resistance on insects. Herein, the detoxification process of Plutella xylostella (L.) carboxylesterase 6 (PxEst-6), one representative P. xylostella carboxylesterase, is investigated with cypermethrin, bifenthrin, cyfluthrin and λ-cyhalothrin. RT-qPCR shows that PxEst-6 is highly expressed in the midgut and cuticles of the third instar larvae. Exposure to pyrethroid insecticides resulted in PxEst-6 up-regulation in a short time. Metabolic assays indicate that PxEst-6 has the capacity to metabolize these pyrethroid insecticides. The combination of molecular docking, binding mode analyses and alanine mutations demonstrated that His451, Lys458 and Gln431 were key residues of PxEst-6 for metabolizing pyrethroids and the acetate groups derived from pyrethroids were key sites for being metabolized by PxEst-6. H451- and K458- derived hydrogen bond (H-bond) interactions with the pyrethroid acetate groups and the polar interactions with the pyrethroid acetate group provided by the Q431 sidechain were crucial to the pyrethroids’ metabolism by PxEst-6. Our study contributes to reducing pyrethroid usage in field, and provides a fundamental basis for the development of novel pyrethroid insecticides.