Physical Biochemistry and Biology of Amyloid Beta-Protein

描述（由申请人提供）：阿尔茨海默病（AD）是一种严重危害老年人的疾病。两种淀粉样蛋白形成蛋白与AD有关，淀粉样蛋白？-蛋白（A?）和tau蛋白。最近的证据支持一种假说，即“淀粉样蛋白级联假说”，该假说认为A？寡聚物是阿尔茨海默病的种子神经致病因子。本提案的总体目标是了解A？，以及其中的片段，并建立正式的构效关系。从长远来看，我们寻求获得一个原子分辨率的结构，确定由A？这样一来，就可以首次开发出改变疾病的阿尔茨海默病治疗方法。将采用多学科策略，采用互补的实验和计算方法。这一策略在过去使用得非常成功，为A？系统。提出了三个具体目标，从体外生物物理研究的系统和逻辑进展？及其寡聚物组装（目标1），体外和体内研究选定的此类组装物的生物活性（目标2），确定选定的组装物对神经元中差异基因表达的影响（目标3）。综上所述，这些研究将为后续治疗性化合物的开发和人体临床试验提供理论和实验基础。目的1。来确定A？和tau组装。a.利用扫描Tyr诱变技术阐明a ？寡聚化。b.确定分子内转弯形成的动力学及其对A？组装。c.确定初级结构变化对生物相关和理论上重要的A？肽。目标2。为了确定A？程序集。a.确定a ？在培养的神经细胞系和原代神经元上组装。b.确定A？果蝇眼睛的发育、运动和寿命。目标3。使用生物信息学方法识别和验证ad相关基因，考虑a ？装配结构、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. PUBLIC HEALTH RELEVANCE: An estimated 5.3 million suffer from Alzheimer's disease (AD) now in the United States. This number is expected to triple before 2050. If this occurs, AD will bankrupt the country, and other countries around the world. The work proposed seeks to determine the proximate neurotoxic agents in AD, and the genes that make neurons susceptible to these agents. Without this information, therapeutic agents to treat, cure, or prevent AD cannot be developed.