New assay method for pinpointing structural features in amyloid oligomer formation

总结 该项目的目标是为生物医学研究提供一项重要的新技术， 特别是对于研究与阿尔茨海默病进展相关的蛋白质的研究人员 疾病（AD）。开发 AD 疗法的大部分努力，其中大部分都已取得进展 靶向 Aβ 原纤维失败了。现在越来越多的证据表明寡聚形式 Aβ 是聚集过程中形成的中间体，可能是造成这种情况的罪魁祸首。 疾病进展。然而，为了设计针对有毒寡聚物种的疗法 或其他改变的蛋白质形式，我们首先需要这些物种的结构信息。在这里，我们 提出一种新的结构方法来表征易聚集的寡聚中间体 系统，并测试与 AD 相关的特定淀粉样肽的新方法。这个 工作将开发一种新的结构分析，协同结合本地和全球 基于结构质谱的方法。羟基自由基溶剂可及性法 揭示了作为构象函数发生的局部残基特异性结构变化 变化或复杂的形成，而本地质谱方法揭示了全局 有关低聚物尺寸和化学计量的结构信息。这些方法将应用于 研究 AD 家族形式中的淀粉样肽以确定寡聚状态 这些肽与野生型不同。新的检测方法还将用于表征 淀粉样肽和 p3 肽之间的相互作用，p3 肽的丰度是淀粉样蛋白肽的两倍 研究更深入的 Aβ，纤维化速度比 Ab 快，但可以减轻 Ab 毒性。最后，我们将联系 这些中间结构形式具有毒性。这些结果将具有巨大的治疗作用 AD 的价值，并将为未来难以研究的结构研究奠定基础 由聚集或错误折叠引起的多种疾病的中间形式 蛋白质。

Summary The goal of this project is to provide a significant new technology for biomedical research, particularly for researchers studying proteins associated with the progression of Alzheimer's Disease (AD). The majority of efforts to develop therapeutics for AD, most of which have targeted Aβ fibrils, have failed. A growing body of evidence now suggests that oligomeric forms of Aβ, which are intermediates that form during the aggregation process, may be the culprits in disease progression. However, in order to design therapeutics targeting toxic oligomeric species or other altered protein forms, we first require structural information on those species. Here, we propose a new structural method to characterize oligomeric intermediates in aggregation-prone systems, and to test the new methodology on specific amyloid peptides implicated in AD. This work will develop a new structural assay which synergistically combines local and global structural mass spectrometry-based methods. The hydroxyl radical solvent accessibility method reveals local residue-specific structural changes that occur as a function of conformational changes or complex formation, while the native mass spectrometry method reveals global structural information on oligomer size and stoichiometry. These methods will be applied to the study of the amyloid peptides in the familial forms of AD to determine how the oligomeric states of these peptides differ from the wildtype. The new assay will also be used to characterize the interaction between amyloid peptides and the p3 peptide, which is twice as abundant as the more well-studied Aβ, fibrilzes faster than Ab, but can mitigate Ab toxicity. Finally, we will relate these intermediate structural forms to toxicity. These results will be of immense therapeutic value for AD, and will lay the groundwork for future structural investigations of difficult-to-study intermediate forms in a wide range of diseases caused by the aggregation or misfolding of proteins.