基于电喷雾质谱技术的羟基化多溴联苯醚与雌激素受体相互作用机理研究

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs), as a novel class of persistent organic pollutants, pose various toxicological effects upon organisms. Their health risk has increasingly attracted considerable concern. In particular, OH-PBDEs may interfere the normal binding between estrogen receptors and natural estrogens. However, the detailed interaction mechanism of OH-PBDEs with estrogen receptors are not fully investigated yet. In this study, a variety of state-of-the-art techniques, including electrospray ionization, multi-dimensional liquid chromatography coupled with tandem mass spectrometry, ion mobility mass spectrometry, hydrogen/deuterium exchange mass spectrometry, molecular simulation, etc., will be applied to explore the interaction between estrogen receptors and a series of diversely structured OH-PBDEs, ranging from hydroxylated monobromodiphenyl ether to hydroxylated octabromodiphenyl ether. Key binding information, including binding stoichiometry, binding constants, and specific binding positions, will be investigated to reveal the structure-activity relationship. Possible conformational changes of estrogen receptors upon the binding of OH-PBDEs will also be characterized to provide scientific basis for the interaction mechanism between OH-PBDEs and estrogen receptors.

羟基化多溴联苯醚作为一类新型持久性有机污染物，对生物体具有多种毒性效应，其健康风险已日益引起人们的高度关注，特别是它可能影响雌激素受体正常结合天然激素而产生内分泌干扰效应。但目前对于羟基化多溴联苯醚与雌激素受体的相互作用机制及致毒机理尚缺乏深入系统的研究。本课题基于电喷雾电离技术，将综合运用多维液相色谱-串联质谱、离子淌度质谱、氢氘交换质谱、分子模拟等前沿技术手段，旨在研究掌握羟基化一溴联苯醚至羟基化八溴联苯醚等24种羟基化多溴联苯醚与雌激素受体非共价相互作用的化学计量学、结合常数、特异性作用位点等关键结合信息，以确定羟基化多溴联苯醚的雌激素效应与其化学结构的构效关系，并表征羟基化多溴联苯醚与雌激素受体结合所诱导的雌激素受体的空间构象变化，从而为全面阐释羟基化多溴联苯醚与雌激素受体的相互作用机理提供科学依据。

羟基化多溴联苯醚对生物体具有多种毒性效应，可造成雌激素转运和代谢紊乱，并可引起神经毒性、细胞毒性和内分泌干扰效应。本研究采用电喷雾质谱法，对具有不同溴原子数目及不同取代位点和不同羟基位点的24种羟基化多溴联苯醚与雌激素受体蛋白的非共价相互作用进行了系统研究。结果表明，2种羟基化七溴联苯醚（6-OH-BDE-180和4-OH-BDE-187）和1种羟基化八溴联苯醚（4’-OH-BDE-201）与雌激素受体蛋白形成了化学计量比分别1:1和1:2的非共价复合物，并对它们的解离常数进行了计算。本研究的实验结果表明，羟基化多溴联苯醚与雌激素受体蛋白具有一定的结合能力，可能干扰雌激素与受体蛋白的正常结合，影响其正常生理功能。进一步采用离子淌度质谱技术，对雌激素受体蛋白结合羟基化多溴联苯醚前后的构象变化进行了研究，推测羟基化多溴联苯醚在与雌激素受体蛋白结合时，可能诱导其构象发生某种变化，使其有利于与羟基化多溴联苯醚的非共价结合。