Sublethal doses of neonicotinoid imidacloprid can interact with honey bee chemosensory protein 1 (CSP1) and inhibit its function
Sublethal doses of neonicotinoid imidacloprid can interact with honey bee chemosensory protein 1 (CSP1) and inhibit its function
复制标题
亚致死剂量的新烟碱类吡虫啉可与蜜蜂化学感应蛋白 1 (CSP1) 相互作用并抑制其功能
DOI：
10.1016/j.bbrc.2017.03.051
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发表时间：
2017-04-29
影响因子：
3.1
通讯作者：
Hu, Fuliang
中科院分区：
文献类型：
--
作者：
Li, Hongliang;Tan, Jing;Hu, Fuliang
作为一种常用的新烟碱类杀虫剂，吡虫啉即使在亚致死剂量下也能损害蜜蜂的趋化行为，但其物理化学机制尚未进一步揭示。本文利用多重荧光光谱、热力学方法和分子对接技术研究了吡虫啉与亚洲蜜蜂重组CSP1蛋白的相互作用及其功能抑制作用。结果表明，吡虫啉对CSP1的荧光强度(em=332 nm)有明显的动态猝灭作用。在猝灭过程中，DELTA H>；0，As>；0，表明吡虫啉与CSP1的作用力主要是疏水相互作用。同步荧光显示，CSP1的荧光主要来源于色氨酸，且随着吡虫啉浓度的增加，色氨酸的疏水性降低。分子对接预测了结合过程的最佳姿势和氨基酸组成。圆二色谱(CD)表明，吡虫啉使CSP1的α-螺旋减少，并导致CSP1肽链的延长。在吡虫啉浓度为0.28~2.53 ng/蜂时，CSP_1与花香紫罗兰酮的结合被近50%的表观结合常数(K-A)抑制；在亚致死剂量水平下，当吡虫啉3.75 ng/蜂时，抑制率接近95%。本研究初步揭示了亚致死剂量的新烟碱仍能相互作用并抑制蜜蜂趋化系统生理功能的分子物理化学机制。(C)2017 Elsevier Inc.保留所有权利。
As a frequently used neonicotinoid insecticide, imidacloprid can impair the chemoreceptive behavior of honey bees even at sublethal doses, while the physiochemical mechanism has not been further revealed. Here, multiple fluorescence spectra, thermodynamic method, and molecular docking were used to study the interaction and the functional inhibition of imidacloprid to the recombinant CSP1 protein in Asian honey bee, Apis cerana. The results showed that the fluorescence intensity (lambda(em) = 332 nm) of CSP1 could be significantly quenched by imidacloprid in a dynamic mode. During the quenching process, Delta H > 0, AS > 0, indicating that the acting forces of imidacloprid with CSP1 are mainly hydrophobic interactions. Synchronous fluorescence showed that the fluorescence of CSP1 was mainly derived from tryptophan, and the hydrophobicity of tryptophan decreased with the increase of imidacloprid concentration. Molecular docking predicted the optimal pose and the amino acid composition of the binding process. Circular dichroism (CD) spectra showed that imidacloprid reduced the alpha-helix of CSP1 and caused the extension of the CSP1 peptide chain. In addition, the binding of CSP1 to floral scent l-ionone was inhibited by nearly 50% of the apparent association constant (K-A) in the presence of 0.28-2.53 ng/bee of imidacloprid, and the inhibition rate of nearly 95% at 3.75 ng/bee of imidacloprid at sublethal dose level. This study initially revealed the molecular physiochemical mechanism that sublethal doses of neonicotinoid still interact and inhibit the physiological function of the honey bees' chemoreceptive system. (C) 2017 Elsevier Inc. All rights reserved.