Pulsed hydrogen-deuterium exchange mass spectrometry probes conformational changes in amyloid beta (Aβ) peptide aggregation
Pulsed hydrogen-deuterium exchange mass spectrometry probes conformational changes in amyloid beta (Aβ) peptide aggregation
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DOI：
10.1073/pnas.1309175110
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发表时间：
2013-09-03
影响因子：
11.1
通讯作者：
Gross, Michael L.
中科院分区：
文献类型：
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作者：
Zhang, Ying;Rempel, Don L.;Gross, Michael L.
由于所得可溶性聚集体存在巨大的异质性，探索淀粉样β (Aβ) 肽聚集的构象变化具有挑战性。为了研究溶液中这些聚集体的形成，我们设计了一种基于 MS 的生物物理方法，并将其应用于 A beta(42) 肽（被认为是阿尔茨海默病的致病因子）的可溶性聚集体的形成。该方法结合了脉冲氢-氘交换和质谱分析。正如之前通过荧光方法观察到的，组合方法为具有滞后期的自催化聚集提供了证据。与这些方法不同，脉冲氢-氘交换不需要修饰的 A beta(42)（例如，用荧光团标记）。此外，该方法揭示了 A beta(42) 的中心区域首先聚集，然后是 C 和 N 末端。我们还发现可溶性物质聚集的滞后阶段受到温度和 Cu2+ 离子的影响。这种 MS 方法具有足够的结构分辨率，可以在生理相关环境中询问 A beta 聚集。该平台通常可用于研究其他淀粉样蛋白形成蛋白和神经毒性可溶性肽聚集体的聚集。
Probing the conformational changes of amyloid beta (A beta) peptide aggregation is challenging owing to the vast heterogeneity of the resulting soluble aggregates. To investigate the formation of these aggregates in solution, we designed an MS-based biophysical approach and applied it to the formation of soluble aggregates of the A beta(42) peptide, the proposed causative agent in Alzheimer's disease. The approach incorporates pulsed hydrogen-deuterium exchange coupled with MS analysis. The combined approach provides evidence for a self-catalyzed aggregation with a lag phase, as observed previously by fluorescence methods. Unlike those approaches, pulsed hydrogen-deuterium exchange does not require modified A beta(42) (e. g., labeling with a fluorophore). Furthermore, the approach reveals that the center region of A beta(42) is first to aggregate, followed by the C and N termini. We also found that the lag phase in the aggregation of soluble species is affected by temperature and Cu2+ ions. This MS approach has sufficient structural resolution to allow interrogation of A beta aggregation in physiologically relevant environments. This platform should be generally useful for investigating the aggregation of other amyloid-forming proteins and neurotoxic soluble peptide aggregates.