Structural studies of amyloid beta globulomers with EPR spectroscopy

项目总结/摘要 阿尔茨海默病是一种致命的神经退行性疾病，是痴呆症的主要病因。的主要风险 老年痴呆症的主要因素是年龄。老年痴呆症的患病率急剧增加， 65岁以上的人，85岁以上的人达到近50%。因此，老年痴呆症 疾病对医疗保健系统构成了巨大的挑战，也是长寿的主要障碍。 广泛的科学研究已经确定了可溶性Aβ聚集体，统称为“寡聚体”， 导致突触功能障碍和神经元死亡的主要神经毒素。详细的结构知识 这些Aβ寡聚体将揭示神经毒性的基础，并促进药物开发， 老年痴呆症不幸的是，这方面的进展非常缓慢。本课题 拟表征由Aβ蛋白的42个残基同种型形成的Aβ球聚体的结构。我们 初步研究表明，利用电子顺磁共振（EPR）光谱，我们能够 解析结构异质性并揭示Aβ寡聚体的反平行结构。该项目将 在这些初步研究的基础上，进一步处理四个具体目标。首先，我们将详细研究 在所有42个残基位置使用自旋标记迁移率分析的Aβ42球聚体的二级结构。第二、 我们将使用分子内距离测量来表征三级结构。三是 通过分子间距离分析表征四级结构。第四，我们将使用蛋白质 结构预测程序Rosetta对Aβ42球聚体的结构进行建模，并交叉验证顶部 使用诱变方法的模型。阿尔茨海默氏症研究领域一直缺乏准确的 Aβ寡聚体的结构模型。该项目的成功将填补这一空白，并提供前所未有的见解 Aβ42寡聚体的结构。对这些低聚物的结构知识将极大地促进 在理解和治疗阿尔茨海默病和其他淀粉样蛋白相关的人类疾病方面的总体努力， 包括帕金森氏症、亨廷顿氏症和2型糖尿病。

Project Summary/Abstract Alzheimer’s disease, the major cause of dementia, is a fatal neurodegenerative disorder. The primary risk factor for Alzheimer’s disease is age. The prevalence of Alzheimer’s disease increases dramatically when people reach 65 years or older, reaching nearly 50% for people of >85 years old. Therefore, Alzheimer’s disease poses an enormous challenge to the healthcare system, and is a major obstacle for longevity. Extensive scientific research has identified soluble Aβ aggregates, collectively termed “oligomers”, as the primary neurotoxins that cause synapse dysfunction and neuronal death. Detailed structural knowledge on these Aβ oligomers would shed light on the basis of neurotoxicity and facilitate drug development to cure Alzheimer’s disease. Unfortunately, the progress on this front has been painfully slow. In this project, we propose to characterize the structure of Aβ globulomers formed by the 42-residue isoform of Aβ protein. Our preliminary studies have shown that, with electron paramagnetic resonance (EPR) spectroscopy, we were able to resolve structural heterogeneity and reveal the antiparallel architecture in Aβ oligomers. This project will build upon these preliminary studies and further tackle four specific aims. First, we will study the detailed secondary structure of Aβ42 globulomers using spin label mobility analysis at all 42 residue positions. Second, we will characterize the tertiary structure using intra-molecular distance measurements. Third, we will characterize the quaternary structure through inter-molecular distance analysis. Fourth, we will use protein structure prediction program Rosetta to model the structure of Aβ42 globulomers and cross-validate the top models using mutagenesis approaches. The field of Alzheimer’s research has suffered from a lack of accurate structural models of Aβ oligomers. Success in this project will fill this gap and provide unprecedented insights into the structures of Aβ42 oligomers. The structural knowledge on these oligomers will greatly facilitate the overall effort in understanding and treating Alzheimer’s disease and other amyloid-involved human diseases, including Parkinson’s, Huntington’s, and type 2 diabetes.