Molecular Mechanisms of Prion and Amyloid Propagation

Pron病是一组可传播的神经退行性疾病，包括克雅氏病 人类的疾病和Gerstmann-Straussler-Scheinker(GSS)病，绵羊和牛的瘙痒病 牛的海绵状脑病(“疯牛病”)和宫颈的慢性衰竭性疾病。最多的 这些疾病的耐人寻味的方面是传染性病毒病原体的性质，据信是一种 错误折叠的蛋白质聚集体，具有淀粉样蛋白的特征。然而，这些传染性的结构 蛋白质颗粒在很大程度上仍不为人所知。该项目的总体目标是获得高分辨率 对Pron传播机制的结构洞察以及Pron菌株和 传播性障碍。为此，我们使用了一个由C末端产生的淀粉样纤维模型 截短的Prion蛋白PrP23-144，一种与GSS样病的Y145停止表型相关的变体。 这个模型的一个独特的优点是，它可以在原子水平上进行详细的结构表征 通过固体核磁共振波谱和其他生物物理技术。三 提出了相关的具体目标。第一个目标是确定高分辨率的结构 几种不同品系的小鼠和叙利亚仓鼠PrP23-144淀粉样纤维的固体核磁共振研究。在……里面 结合我们已经确定的人PrP23-144淀粉样蛋白的高分辨结构， 这些数据将被用来深入了解PrP淀粉样蛋白种子特异性的结构基础，在 传播性障碍的体外替代物。在第二个目标中，我们将使用PrP23-144淀粉样蛋白模型 阐明鲜为人知的Pron株系转换现象以及株系机制 选择。最后，第三个目标寻求确定与PrP相关的淀粉样蛋白的高分辨率结构 具有明显的GSS疾病表型。后一种洞察是至关重要的，因为没有信息 目前关于GSS相关PrP淀粉样蛋白的结构或两者之间的关系是可用的 特殊的结构特征和疾病表型。

Prion diseases are a group of transmissible neurodegenerative disorders that include Creutzfeldt-Jakob disease and Gerstmann-Straussler-Scheinker (GSS) disease in humans, scrapie in sheep, bovine spongiform encephalopathy (“mad cow disease”) in cattle and chronic wasting disease in cervids. The most intriguing aspect of these disorders is the nature of the infectious prion pathogen that is believed to be a misfolded protein aggregate with characteristics of an amyloid. However, the structure of these infectious protein particles remains largely unknown. The overall objective of this project is to gain high-resolution structural insight into the mechanism of prion propagation as well as the phenomena of prion strains and transmissibility barriers. To this end, we use a model of amyloid fibrils generated from the C-terminally truncated prion protein PrP23-144, a variant associated with the Y145Stop phenotype of a GSS-like disease. A unique advantage of this model is that it is amenable to detailed structural characterization at atomic level by solid-state nuclear magnetic resonance (NMR) spectroscopy and other biophysical techniques. Three interrelated specific aims are proposed. The first aim is to determine the high-resolution structures for several different strains of mouse and Syrian hamster PrP23-144 amyloid fibrils using solid-state NMR. In combination with the high-resolution structure of human PrP23-144 amyloid already determined by us, these data will be used to gain insight into the structural basis of PrP amyloid seeding specificities, an in vitro surrogate of transmissibility barriers. In the second aim, we will use the PrP23-144 amyloid model to elucidate the poorly understood phenomenon of prion strain switching as well as the mechanism of strain selection. Finally, the third aim seeks to determine high-resolution structures of PrP amyloids associated with distinct phenotypes of GSS disease. The latter insight is of fundamental importance, as no information is at present available regarding the structures of GSS-associated PrP amyloids or the relationship between specific structural features and disease phenotype.