A novel thermostable and salt-tolerant carboxylesterase involved in the initial aerobic degradation pathway for pyrethroids in Glycomyces salinus.
A novel thermostable and salt-tolerant carboxylesterase involved in the initial aerobic degradation pathway for pyrethroids in Glycomyces salinus.
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DOI：
10.1016/j.jhazmat.2023.131128
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发表时间：
2023-03
影响因子：
13.6
通讯作者：
Yan Liu;Shukun Tang;Xu Wang;Xiaoliang Wang;Xianghua Tang;Qian Wu;Zunxi Huang;Junmei Ding
中科院分区：
文献类型：
--
作者：
Yan Liu;Shukun Tang;Xu Wang;Xiaoliang Wang;Xianghua Tang;Qian Wu;Zunxi Huang;Junmei Ding
长期和过度使用拟除虫菊酯农药会造成严重的健康风险和生态系统问题。已经报道了几种可以降解拟除虫菊酯的细菌和真菌。使用水解酶的酯键水解是拟除虫菊酯的初始调节代谢反应。然而，在这一过程中所涉及的水解酶的彻底的生物化学表征是有限的。本文报道了一种新的能水解拟除虫菊酯的羧酸酯酶，命名为EstGS 1。EstGS 1与其他已报道的拟除虫菊酯水解酶相比显示出较低的序列同一性（<27.03%），并且属于优选短链酰基酯（C2至C8）的羟基腈裂解酶家族。以pNPC 2为底物，在60 °C和pH8.5条件下，EstGS 1的最大酶活为213.38 U/mg，最大Km值分别为2.21 ± 0.72 mM和212.90 ± 41.78 μM/min。EstGS 1是一种耐盐酯酶，在5.1 M NaCl中保持稳定。基于分子对接和突变分析，催化三联体S74-D181-H212和另外三个底物结合残基I108、S159和G75是EstGS 1酶活性的关键。20 U的EstGS 1可在4 h内水解61和40 mg/L的溴氰菊酯和λ-氯氟氰菊酯。本工作首次报道了一种拟除虫菊酯类农药水解酶，其特征在于嗜盐放线菌。
The long-term and excessive use of pyrethroid pesticides poses substantial health risks and ecosystem concerns. Several bacteria and fungi have been reported that could degrade pyrethroids. The ester-bond hydrolysis using hydrolases is the initial regulatory metabolic reaction of pyrethroids. However, the thoroughly biochemical characterization of hydrolases involved in this process is limited. Here, a novel carboxylesterase, designated as EstGS1 that could hydrolyze pyrethroid pesticides was characterized. EstGS1 showed low sequence identity (<27.03%) compared to other reported pyrethroid hydrolases and belonged to the hydroxynitrile lyase family that preferred short short-chain acyl esters (C2 to C8). EstGS1 displayed the maximal activity of 213.38 U/mg at 60 °C and pH 8.5 usingpNPC2 as substrate, withKmandVmaxwere 2.21 ± 0.72 mM and 212.90 ± 41.78 µM/min, respectively. EstGS1 is a halotolerant esterase and remains stable in 5.1 M NaCl. Based on molecular docking and mutational analysis, the catalytic triad of S74-D181-H212and three other substrate-binding residues I108, S159, and G75are critical for the enzymatic activity of EstGS1. Additionally, 61 and 40 mg/L of deltamethrin and λ-cyhalothrin were hydrolyzed by 20 U of EstGS1 in 4 h. This work presents the first report on a pyrethroid pesticide hydrolase characterized from a halophilic actinobacteria.