Elucidating the biophysical and biological properties of the p3 fragment in Alzheimer's Disease

项目摘要 阿尔茨海默病是美国第六大死亡原因，影响10%的65岁以上老年人。 尽管有无数针对β-淀粉样蛋白的产生和清除的阿尔茨海默病疗法， （Aβ）肽，有效的治疗方法尚未确定。目前，普遍接受的淀粉样蛋白模型， 疾病只寻求了解Aβ -的两种主要亚型的特性，它们具有40或42个氨基酸。 然而，从阿尔茨海默氏症患者的脑中分离的斑块含有多种Aβ肽和其他蛋白质。 proteins.这项研究的长期目标是阐明Aβ及其受体的作用机制。 这些变异共同促成了阿尔茨海默病的病理学。Aβ的C端片段p3具有 自发现以来，尽管科学研究很少， 证据来支持这一点。我建议合成和表征的聚集和机制的毒性 p3以阐明其在淀粉样纤维形成中的作用。我的假设是p3片段形成淀粉样纤维 能够对充分研究的40和42长度Aβ的寡聚化产生剧烈变化。当前 淀粉样蛋白模型可以通过了解所有Aβ肽的集体贡献而得到显著改善 通过它们的动力学相互作用。目的我将提供关于p3如何聚集成淀粉样纤维以及如何形成淀粉样纤维的见解。 通过使用动力学测定、抗体和光诱导交联，该途径偏离Aβ。目的2 将通过共孵育为淀粉样肽聚集成纤维创造一个更异质的模型 以及用p3和Aβ的接种测定。目标3将提供我们对p3如何发挥其作用的理解的进展。 对细胞的毒性以及该途径与Aβ的不同。p3毒性的机制将与 各种双正交细胞摄取方法和凋亡测定。完成列出的目标将阐明 P3在淀粉样蛋白斑形成和细胞毒性的动力学中所起的作用。通过提供关键的见解， p3的聚集特性和生物学活性，拟开展的工作将阐明p3如何与Aβ相互作用。 最终，我希望这些结果能够修改和完善目前公认的淀粉样蛋白模型， 更全面地了解阿尔茨海默病的病理学。

PROJECT SUMMARY Alzheimer’s Disease is the 6th leading cause of death in the U.S, affecting 10% of seniors over the age of 65. Despite the myriad Alzheimer’s Disease therapeutics targeting the production and clearance of the β-Amyloid (Aβ) peptide, an effective cure is yet to be identified. The current, commonly accepted amyloid model of this disease only seeks to understand the properties of two predominant isoforms of Aβ - with 40 or 42 amino acids. However, plaques isolated from the brains of Alzheimer’s patients contain a variety of Aβ peptides and other proteins. The long-term objective of the proposed research is to elucidate the mechanisms by which Aβ and its variants contribute collectively to the pathology of Alzheimer’s Disease. A C-terminal fragment of Aβ, p3, has been described as soluble and void of amyloidogenic properties since its discovery, despite minimal scientific evidence to support this. I propose to synthesize and characterize the aggregation and mechanism of toxicity of p3 to elucidate its role in amyloid fibril formation. My hypothesis is that the p3 fragment forms amyloid fibrils capable of imparting drastic changes on the oligomerization of the well-studied 40 and 42 length Aβ. The current amyloid model can be significantly improved by understanding the collective contribution of all Aβ peptides through their kinetic interactions. Aim I will provide insights on how p3 aggregates into amyloid fibrils and how that pathway deviates from Aβ with the use of kinetic assays, antibodies and photo-induced crosslinking. Aim 2 will create a more heterogenous model for the aggregation of amyloid peptides into fibrils through coincubation and seeding assays with p3 and Aβ. Aim 3 will provide advances in our understanding of how p3 exerts its toxicity on cells and how that pathway differs from that of Aβ. The mechanism of p3 toxicity will be explored with various biorthogonal cellular uptake methods and apoptosis assays. Completing the listed aims will elucidate the role that p3 plays in the kinetics of amyloid plaque formation and cell toxicity. By providing key insights into the aggregation properties and biological activity of p3, the proposed work will clarify how p3 interacts with Aβ. Ultimately, I expect the results to modify and refine the currently accepted amyloid model, providing a more comprehensive understanding of the pathology of Alzheimer’s Disease.