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种重要的新技术， 特别是对于研究与阿尔茨海默氏症进展相关的蛋白质的研究人员来说， 疾病（AD）。开发AD治疗药物的大多数努力，其中大部分已经 靶向Aβ原纤维，已经失败。越来越多的证据表明， Aβ是聚集过程中形成的中间体，可能是 疾病进展。然而，为了设计靶向毒性寡聚物种类的治疗剂， 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。这里我们 提出了一种新的结构方法来表征聚合倾向中的低聚中间体 系统，并测试新的方法对特定的淀粉样肽牵连在AD。这 工作将开发一种新的结构分析，协同结合当地和全球 基于结构质谱的方法。羟基自由基溶剂可及性法 揭示了作为构象的函数发生的局部残留物特异性结构变化 变化或复杂的形成，而本地质谱法揭示了全球 关于低聚物尺寸和化学计量的结构信息。这些方法将应用于 研究家族性AD中的淀粉样肽，以确定寡聚体状态 与野生型不同。新的检测方法也将用于表征 淀粉样蛋白肽和p3肽之间的相互作用，其丰度是淀粉样蛋白肽的两倍。 更充分研究的Aβ，原纤化比Ab更快，但可以减轻Ab毒性。最后，我们将 这些中间结构形式的毒性。这些结果将是巨大的治疗 价值，并将奠定基础，为今后的结构调查，难以研究 中间形式在广泛的疾病引起的聚集或错误折叠的 proteins.

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.