Probing Conformational Dynamics of Tau Protein by Hydrogen/Deuterium Exchange Mass Spectrometry
Probing Conformational Dynamics of Tau Protein by Hydrogen/Deuterium Exchange Mass Spectrometry
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DOI：
10.1007/s13361-017-1815-8
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发表时间：
2018-01-01
影响因子：
3.2
通讯作者：
Chen, Guodong
中科院分区：
文献类型：
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作者：
Huang, Richard Y. -C.;Iacob, Roxana E.;Chen, Guodong
微管相关蛋白tau的纤维化已被认为是阿尔茨海默病、进行性核上性麻痹和其他tau病神经系统的标志性病理之一。在纤化过程中，tau的构象转变，特别是tau单体到可溶性聚集体再到纤维，目前还不清楚。在这里，我们报告了氢/氢交换质谱仪结合其他生化方法的使用，包括硫代黄素S荧光测量、酶联免疫吸附试验(ELISA)和Western blotting，以了解肝素诱导的tau的纤化。包括抗tau抗体表位映射实验在内的HDX-MS研究提供了tau全长构象动力学的分子水平细节，以及其在形成可溶性聚集体时的区域溶剂可及性。结果表明，在聚集过程中，全长tau的微管结合重复区域(MTBR)中的R3区是稳定的，N和C末端区域在可溶性聚集体和纤维中都暴露在溶剂中。这些发现也说明了正交分析方法在表征蛋白质高阶结构方面的实用价值。
Fibrillization of the microtubule-associated protein tau has been recognized as one of the signature pathologies of the nervous system in Alzheimer's disease, progressive supranuclear palsy, and other tauopathies. The conformational transition of tau in the fibrillization process, tau monomer to soluble aggregates to fibrils in particular, remains unclear. Here we report on the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) in combination with other biochemical approaches, including Thioflavin S fluorescence measurements, enzyme-linked immunosorbent assay (ELISA), and Western blotting to understand the heparin-induced tau's fibrillization. HDX-MS studies including anti-tau antibody epitope mapping experiments provided molecular level details of the full-length tau's conformational dynamics and its regional solvent accessibility upon soluble aggregates formation. The results demonstrate that R3 region in the full-length tau's microtubule binding repeat region (MTBR) is stabilized in the aggregation process, leaving both N and C terminal regions to be solvent exposed in the soluble aggregates and fibrils. The findings also illustrate the practical utility of orthogonal analytical methodologies for the characterization of protein higher order structure.