Structural and mechanistic studies of amyloids related to Alzheimer's disease and Parkinson's disease using engineered binding proteins

阿尔茨海默病（Alzheimer ' s disease， AD）发病的关键步骤是阿尔茨海默病（Alzheimer ' s disease， AD）中淀粉样斑块形成的寡聚化和聚集。因此，针对ß的产生、聚集和清除的抗淀粉样蛋白方法是目前开发AD治疗方法的重点。本提案的目标是通过提供对亚ß寡聚化，纤维形成和分解的分子方面的见解来支持这些方法。建议的研究项目利用了一种工程结合蛋白（附着体），它能够稳定单体asb。首先，将利用a ß特异的粘附体(i)在试管中通过核磁共振光谱和（ii）在AD的苍蝇模型中研究a ß的单体与疾病相关的寡聚体和纤维状态之间的平衡和转变。其次，将特别有毒的asas（1- 42）和asas的北极变体的附着体复合物的NMR结构与先前确定的asas（1-40）的复合物结构进行比较，以确定肽的构象偏好的潜在差异。第三，与帕金森病相关的淀粉样蛋白a-synuclein与a-synuclein特异性粘附体的相互作用将在生物物理和结构上进行表征。与a ß特异性粘附体的潜在相似性将阐明淀粉样蛋白的共性，并可能为淀粉样蛋白疾病提供一种通用的治疗方法。

The oligomerization and aggregation of the Alzheimer Aß peptide (Aß) resulting in amyloid plaque formation has been implicated as a key step in Alzheimer s disease (AD) pathogenesis. Consequently, anti-amyloid approaches, which target the production, aggregation and clearance of Aß, constitute the focus of current efforts to develop AD therapeutics. The goal of the present proposal is to support such approaches by providing insight into the molecular aspects of Aß oligomerization, fibril formation, and disaggregation. The suggested research project takes advantage of an engineered binding protein (affibody) which is capable of stabilizing monomeric Aß. First, the Aß-specific affibody will be employed to investigate the equilibria and transitions between the monomeric and the disease-related oligomeric and fibrillar states of Aß (i) in the test tube by NMR spectroscopy, and (ii) in a fly model of AD. Second, the NMR structures of the affibody complexes of the particularly toxic Aß(1- 42) and arctic variants of Aß will be compared with the previously determined complex structure of Aß(1-40) in order to identify potential differences in the conformational preferences of the peptides. Third, the interaction of the protein a-synuclein, which forms amyloid linked to Parkinson s disease, with an a-synucleinspecific affibody will be characterized biophysically and structurally. Potential similarities with the Aß-specific affibody would elucidate commonalities of amyloidogenic proteins and might suggest a general therapeutic approach towards amyloid diseases.