Physical Biochemistry and Biology of Amyloid Beta-Protein

描述（由申请人提供）：阿尔茨海默病（AD）是一种老年人的毁灭性疾病。两种淀粉样蛋白形成蛋白与AD相关，淀粉样蛋白？蛋白质（A？）和tau。最近的证据支持一个假说，“淀粉样级联假说”，假定A？寡聚体是AD中的种子神经致病剂。本提案的总体目标是了解A？的结构生物学，及其片段，并建立正式的结构-活性关系。从长远来看，我们试图获得一个原子分辨率的结构确定的近端神经毒素形成的A？，并且在这样做的过程中，第一次能够开发出改善疾病的AD治疗方法。一个多学科的战略，采用互补的实验和计算方法，将采用。这一战略已被成功地使用在过去，提供了新的见解A？系统三个具体的目标，提出了系统和逻辑的进展，从体外生物物理研究的A？及其寡聚体组装体（Aim 1），体外和体内研究选定的此类组装体的生物活性（Aim 2），确定选定的组装体对神经元中差异基因表达的影响（Aim 3）。总之，这些研究将为后续的治疗性化合物开发和人体临床试验提供理论和实验基础。目标1。为了确定结构动态的A？和tau组装。a.用扫描Tyr突变来阐明A？低聚反应B.为了确定分子内转向形成的动力学及其对A？组装件. C.为了确定一级结构的变化对生物相关的和理论上重要的A的构象和组装动力学的影响？缩氨酸目标二。为了确定生物效应的A？组件. a.确定A？在培养的神经元细胞系和原代神经元上组装。B.为了确定A？果蝇眼睛发育，运动和寿命的组件。目标3：识别和验证AD相关基因的生物信息学方法，认为A？组装结构、神经元类型和神经元衰老。

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a devastating disease of the aged. Two amyloid-forming proteins are associated with AD, the amyloid ?-protein (A?) and tau. Recent evidence supports an hypothesis, the "amyloid cascade hypothesis," that posits that A? oligomers are the seminal neuropathogenetic agents in AD. The overall goal of this proposal is to understand the structural biology of A?, and fragments thereof, and to establish formal structure-activity relationships. In the long run, we seek to obtain an atomic-resolution determination of the structure of the proximate neurotoxins formed by A?, and in doing so, enable the development, for the first time, of disease-modifying AD treatments. A multidisciplinary strategy, employing complementary experimental and computational approaches, will be employed. This strategy has been used very successfully in the past, providing novel insights into the A? system. Three specific aims are proposed that systematically and logically progress from in vitro biophysical studies of A? and its oligomeric assemblies (Aim 1), to in vitro and in vivo studies of the biological activity of selected such assemblies (Aim 2), to determination of the effects of selected assemblies on differential gene expression in neurons (Aim 3). Taken together, these studies will provide the theoretical and experimental foundation for subsequent therapeutic compound development and clinical testing in humans. Aim 1. To determine the structural dynamics of A? and tau assembly. a. To use scanning Tyr mutagenesis to elucidate mechanisms of A? oligomerization. b. To determine the dynamics of intramolecular turn formation and its effects on A? assembly. c. To determine the effects of primary structure changes on the conformations and assembly dynamics of biologically relevant and theoretically important A? peptides. Aim 2. To determine the biological effects of A? assemblies. a. To determine the cytotoxic effects of A? assemblies on cultured neuronal cell lines and primary neurons. b. To determine the effects of A? assemblies on Drosophila eye development, locomotion, and longevity. Aim 3. To identify and validate AD-relevant genes using a bioinformatics approach that considers A? assembly structure, neuron type, and neuron senescence.