Elucidating molecular structure of mammalian prions

描述（由申请人提供）：朊病毒蛋白（PrP）是一系列疾病的基础，没有既定的治疗方法，对人类和经济造成毁灭性后果。虽然在了解朊病毒感染因子的生化性质方面取得了重大进展，但缺乏朊病毒蛋白（PrPSc）聚集的疾病相关形式的详细结构信息是该领域进展的主要障碍。在当前的应用中，我们建议使用最先进的技术来阐明有序的、与疾病相关的朊病毒蛋白聚集体的结构，包括固态核磁共振方法，并辅以每长度质量和每长度体积测量。这三个具体目标集中在阐明三种均质但构象不同形式的有序PrP聚集体的分子结构，这些聚集体是在明确的条件下使用高纯度的全长重组PrP在体外制备的。它们分别包括具有高感染性滴度的PrPSc和两种具有有限感染性或无法检测到感染性的PrP淀粉样原纤维。当该项目的目标完成后，目前的研究将确定区分自繁殖有序PrP聚集体的感染性和非感染性状态的结构特征，并确定朊病毒感染性的分子决定因素。最终，从这项研究中获得的见解将有助于开发针对朊病毒疾病的有效治疗方法，并更好地了解朊病毒复制的机制。此外，这些研究将为理解与其他神经退行性疾病相关的非朊病毒蛋白异常构象的朊病毒样复制机制奠定基础。

DESCRIPTION (provided by applicant): Prion protein (PrP) underlies a spectrum of diseases with no established treatment and devastating human and economic consequences. While substantial progress has been made in understanding the biochemical nature of the prion infectious agent, the lack of detailed structural information about the aggregated, disease-related forms of the prion protein (PrPSc) is a major barrier to progress in the field. In the current application, we propose to elucidate the structures of ordered, disease-related prion protein aggregates using state-of-the-art techniques including solid-state NMR methods supplemented with mass-per-length and volume-per-length measurements. The three specific aims are focused on elucidating the molecular structures of three homogeneous but conformationally distinct forms of the ordered PrP aggregates prepared in vitro using highly pure full-length recombinant PrP under well-defined conditions. They include PrPSc with a high infectivity titer and two types of PrP amyloid fibrils with limited infectivity or no detectible infectivity, respectively. When the goals of this project are accomplished, the current study will identify structural features that distinguish infectious and non- infectious states of self-propagating ordered PrP aggregates and define molecular determinants of prion infectivity. Ultimately, insight gained from this research will aid in the efforts to develop effective therapeutics for prion diseases and a better understanding of the mechanisms of prion replication. Furthermore, these studies will lay the ground work for understanding the mechanisms responsible for prion-like replication of abnormal conformation of non-prion proteins associated with other neurodegenerative diseases.