Degenerative and Dementing Diseases of Aging

描述(申请人提供)：在这份由四个科学项目和四个核心组成的申请中，我们建议继续我们的研究，重点是由人类Pron疾病引起的神经变性，其中最常见的是散发性(S)CJD。Prion似乎只由PrPSc分子组成，PrPSc分子是由一种鲜为人知的过程从PrPc前体衍生而来的。这里描述的研究旨在定义PrPSc的结构，表征小分子与PrPc和PrPSc的相互作用，并剖析控制不同人类PrPc菌株繁殖的分子事件。在项目1中，我们建议研究多金属氧酸盐(POMS)与PrPSc的相互作用。POM磷钨酸盐阴离子[PW12O40](PTA)与PrPSc特异结合，但不与PrP结合。POMS是一大类具有刚性多面体结构的无机金属氧化物团簇，在大小、形状和电荷密度方面都有很大的变化。在项目2中，我们建议对导致遗传性Prion病的55个残基的MoPrP(89-143，P101L)肽、已知可形成淀粉样纤维的20mer wt PrP(106-126)肽以及在野生型动物中具有传染性的纯化截短PrP(PrP 27-30)和全长PrPSc进行纤维衍射研究。在项目3中，我们建议研究引起sCJD的普里子。这些研究之所以可能，是因为我们最敏感的表达人/鼠嵌合型PrP的TG小鼠系在接种sCJD普恩病毒后约80天内死亡。在这些转基因小鼠身上相对快速地进行人类普恩病毒的生物检测，使得测量整个大脑以及从死亡的sCJD患者身上收集的外周器官和体液中的普恩病毒的滴度变得切实可行。我们还建议建立sCJD和变异型(V)CJD的豚鼠模型。在项目4中，我们计划发现与人PrPC结合并稳定的新配体。我们还计划确定这些配体是否抑制HuPrPc向HuPrPSc的转化。使用虚拟筛选方法，大型有机分子文库将与HuPrPc的已知结构对接。得分高的化合物将接受生物物理结合测试，控制抗淀粉样蛋白抑制剂容易出现的非特异性抑制。所有拟议研究的最终目标都是为了开发治愈人类普恩疾病的疗法，定义在人类普恩形成过程中具有特征的分子事件。

DESCRIPTION (provided by applicant): In this application comprising four scientific projects and four-cores, we propose to continue our studies focused on neurodegeneration caused by human prion diseases, the most common of which is sporadic (s) CJD. Prions seem to be composed solely of PrPSc molecules, which are derived from a precursor PrPc by a poorly understood process. The studies described here are aimed at defining the structure of PrPSc, characterizing the interactions of small molecules with both PrPc and PrPSc and dissecting the molecular events governing the propagation of different human prion strains. In Project 1, we propose to study the interactions of polyoxometalates (POMs) with PrPSc. The POM phosphotungstate anion [PW12O40] (PTA) binds specifically to PrPSc, but not to PrP. POMs are a large class of inorganic metal oxide clusters with rigid polyhedral structures displaying substantial variations in size, shape, and charge density. In Project 2, we propose to carry out fiber diffraction studies of the 55-residue MoPrP(89-143,P101L) peptide that causes inherited prion disease, a 20 mer wt PrP(106-126) peptide known to form amyloid fibrils as well as purified truncated (PrP 27-30) and full-length PrPSc, both of which are infectious in wild-type animals. In Project 3, we propose to study the prions causing sCJD. These studies are possible because our most sensitive Tg mouse line expressing chimeric human/mouse PrP succumbs to disease in ~80 days after inoculation with sCJD prions. Relatively rapid bioassays of human prions in these Tg mice make it practical to measure the titers of prions throughout brain as well as in peripheral organs and body fluids collected from dead sCJD patients. We also propose to develop guinea pig models of sCJD and variant (v) CJD. In Project 4, we propose to discover new ligands that bind to and stabilize human PrPc. We also plan to determine whether such ligands inhibit the conversion of HuPrPc into HuPrPSc. Using a virtual screening approach, large libraries of organic molecules will be docked against the known structure of HuPrPc. High-scoring compounds will be tested for binding biophysically, controlling for non-specific inhibition to which anti-amyloid inhibitors are prone. The ultimate goal of all the proposed studies is to define the molecular events that feature in the formation of human prions in order to develop therapeutics that cure the human prion diseases.