多光谱法研究啶虫脒与牛血清白蛋白的相互作用  

Study on Interaction Between Acetamiprid and Bovine Serum Albumin by Multispectral Analysis

作　　者：李嘉兴 李坤 刘世杰 曾浩宇 杨娟[1] Li Jiaxing;Li Kun;Liu Shijie;Zeng Haoyu;Yang Juan(School of Ecology and Environment,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学生态与环境学院,昆明650224

出　　处：《生态毒理学报》2024年第1期207-222,共16页Asian Journal of Ecotoxicology

基　　金：云南省应用基础研究计划面上项目(202101AT070046);国家自然科学基金资助项目(22166033);云南省科技厅重点研发计划项目(202203AC100001);云南省农业联合面上项目(202101BD070001-112)。

摘　　要：啶虫脒(acetamiprid,ACE)是一种广泛使用的新烟碱类杀虫剂,其在环境介质中的残留积累,对哺乳动物产生神经毒性作用,成为一种备受关注的环境污染物。为清晰认识啶虫咪在生物体中的作用过程,本研究利用荧光、紫外可见光(UV-vis)、圆二色光谱法及分子对接技术,探究了ACE和牛血清白蛋白(bovine serum albumin,BSA)的相互作用机制。结果表明:在不同温度下,BSA和ACE的荧光猝灭机制主要为静态猝灭,能够形成基态复合物,且存在至少1个结合位点;热力学研究表明,二者结合过程中的吉布斯自由能(ΔG)为负值,说明ACE与BSA的结合是一个自发过程;焓(ΔH)和熵(ΔS)为负值,表明ACE与BSA相互作用的驱动力是氢键或范德华力;通过荧光光谱法和UV-vis光谱法算出结合距离小于7 nm,表明ACE与BSA之间能发生非辐射能量转移;同步荧光光谱显示ACE对BSA的构象产生影响,主要是对其中酪氨酸残基的影响更为显著;圆二色光谱结果显示ACE使BSA的构象发生一定变化,增加了α-螺旋结构的稳定性和蛋白整体的有序性,使蛋白质的微环境比其天然状态更具疏水性。综上所述,ACE与BSA在环境介质和生物体中能够自发结合,形成稳定的基态复合物,且结合后会影响BSA的结构。本研究为探究ACE在生物体中的致毒过程提供了基础数据。Acetamiprid(ACE),a prevalently used neonicotinoid insecticide,has been identified as a notable environmental contaminant due to its neurotoxic accumulation in ecological systems,impacting mammalian health.This research delves into the intricate interaction mechanisms between ACE and bovine serum albumin(BSA),employing a suite of multispectral methodologies,including fluorescence,ultraviolet-visible(UV-vis)spectroscopy,and circular dichroism.The study unveils that the interaction between BSA and ACE,across varying temperature ranges,is predominantly characterized by static fluorescence quenching.This mechanism facilitates the formation of a ground state complex,featuring at least one specific binding site.Thermodynamic analysis reveals a spontaneous nature of the ACE-BSA interaction,as evidenced by negative Gibbs free energy(ΔG).Furthermore,the interaction is thermodynamically driven by hydrogen bonding or van der Waals forces,inferred from the negative values of enthalpy(ΔH)and entropy(ΔS).The binding proximity,determined to be less than 7 nm through fluorescence and UV-vis spectroscopic measurements,suggests a potential non-radiative energy transfer between ACE and BSA.Notably,synchronous fluorescence spectroscopy indicates a significant conformational impact of ACE on BSA,with a pronounced effect on the tyrosine residues.Circular dichroism spectroscopy results corroborate these findings,revealing ACE-induced alterations in BSA’s conformation,notably enhancing the stability of theα-helix structure and the overall protein organization,thus rendering the protein’s microenvironment more hydrophobic compared to its native state.Collectively,these findings demonstrate the spontaneous and stable complex formation between ACE and BSA in environmental and biological matrices,with consequential structural modifications to BSA.This study lays the groundwork for further exploration into ACE’s toxicological mechanisms within biological systems.

关 键 词：啶虫脒 牛血清白蛋白 神经毒性 荧光光谱法 UV-vis光谱法 圆二色光谱法 

分 类 号：X171.5[环境科学与工程—环境科学]