INHIBITION AND MECHANISM OF AMYLOID BETA-AGGREGATION

β淀粉样蛋白聚集的抑制及其机制

• 批准号: 6509819
• 负责人: MICHAEL Gerard ZAGORSKI
• 金额: $ 22.35万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-01 至 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6509819
• 关键词: aging; amyloid proteins; amyloidosis; apolipoprotein E; biophysics; carbon; chemical aggregate; chemical association; conformation; cytotoxicity; inhibitor /antagonist; molecular dynamics; molecular pathology; neurofibrillary tangles; nitrogen; nuclear magnetic resonance spectroscopy; protein structure function; stable isotope; water solution

Description (From the applicant's abstract): The neuropathological hallmarks of Alzheimer's disease (AD) are the abundance of intraneuronal neurofibrillary tangles and the extracellular deposition of the Abeta peptide as amyloid plaques. Extensive genetic and cell viability studies support a key role for the Abeta peptide in AD neurodegeneration. The Abeta pathologic effects are related to the formation of insoluble aggregates dominated by beta-sheet structures. Biochemical studies suggest that the longer, 42-residue Abeta (1-42) is more pathogenic than the shorter, 40-residue Abeta (1-40), due to its greater in vitro tendency to aggregate and precipitate as amyloid. Nonetheless, a molecular basis for the greater pathogenicity of the Abeta (1-42) has yet to be determined. Our laboratory is one of the few research groups that has successfully applied high-resolution NMR methods to study the structure and aggregational properties of the Abeta peptides. The NMR approach is extremely powerful for studying proteins, in that it can detect site-specific aspects of the structures and dynamics in solution at the atomic level. Using NMR, we have discovered differences between the monomeric forms of the Abeta (1-40) and Abeta (1-42) in water solution at pH 7.2, in which the Abeta (1-42) displayed multiple NH peaks for Val36, Gly37, Gly38, and Val39, a region previously implicated to contain a cis peptide bond that could be important for initiating beta-amyloidosis. Our NMR results may account for the greater beta-aggregation of the Abeta (1-42), and we hypothesize that the monomeric Abeta (1-42) adopts a unique structure not present for monomeric Abeta (1-40). This application contains three well-coupled, specific aims. The first aim will be to explore the effects of D-Asp, D-Ser and iso-Asp on the structure and beta-aggregation rates of the Abeta (1-42). We hypothesize that these permutations alter the structure in a manner to create a seed" that nucleates beta-amyloidosis. Aim 2 will examine the dynamics of the Abeta association in aqueous solution using 15N and 13C NMR relaxation studies. We will carefully compare the site-specific association of the Abeta (1-40) and Abeta (1-42), and determine if cis-trans isomerization occurs at the Gly37-Gly38 peptide bond for monomeric Abeta (1-42). To locate putative inhibitor bindings sites or surfaces, Aim 3 will conduct NMR binding studies with macromolecules (such as ApoE and ApoJ) and presumed amyloid inhibitors with monomeric Abeta (1-40) and Abeta (1-42). This information has potential for additives and drug candidates to interfere with the beta-aggregation process and provide detailed structural information about the biding mode of amyloid inhibitors. With these data, a more rational approach to the design of less toxic and more effective inhibitors of beta-amyloidosis will be explored by collaboration with scientists in the medical school.

描述（摘自申请人的摘要）：神经病理学的标志 阿尔茨海默氏病（AD）是丰富的神经内神经纤维 Abeta肽作为淀粉样蛋白的缠结和细胞外沉积 斑块。广泛的遗传和细胞生存力研究支持 AD神经变性中的Abeta肽。 ABETA病理影响是 与以beta表统治的不溶性聚集体的形成有关 结构。生化研究表明，较长的42个沉重的Abeta （1-42）由于其较短的40二余Abeta（1-40）而更具致病性 更大的体外趋势是聚集和沉淀为淀粉样蛋白的趋势。尽管如此， ABETA较高致病性的分子基础（1-42）尚未 可以确定。 我们的实验室是成功应用的少数研究小组之一 研究结构和聚集特性的高分辨率NMR方法 Abeta肽的NMR方法非常有力地学习 蛋白质，它可以检测结构的特定地点方面 原子水平的溶液中的动力学。使用NMR，我们发现了 Abeta（1-40）的单体形式和Abeta（1-42）之间的差异 pH 7.2的水溶液，其中Abeta（1-42）显示了多个NH峰 对于Val36，Gly37，Gly38和Val39，一个以前牵涉到包含A的区域 顺式肽键可能对引发β-淀粉样变性很重要。我们的 NMR结果可能是ABETA（1-42）的更大β-聚集 我们假设单体Abeta（1-42）采用了独特的结构 单体Abeta不存在（1-40）。 该应用程序包含三个耦合良好的特定目的。第一个目标 要探索D-ASP，D-SER和ISO-ASP对结构的影响 ABETA的β-聚集率（1-42）。我们假设这些 置换以某种方式改变结构，以创建成核的种子 β-淀粉样变性。 AIM 2将检查Abeta协会的动态 使用15N和13C NMR松弛研究的水溶液。我们会谨慎 比较Abeta（1-40）和Abeta（1-42）的特定地点关联，以及 确定是否在Gly37-Gly38肽键处发生顺式传播异构化 单体ABETA（1-42）。找到推定的抑制剂结合位点或 表面，AIM 3将对大分子进行NMR结合研究（例如 APOE和APOJ）和假定具有单体Abeta（1-40）的淀粉样蛋白抑制剂和 Abeta（1-42）。此信息具有添加剂和候选药物的潜力 干扰β-聚集过程并提供详细的结构 有关淀粉样蛋白抑制剂的借助模式的信息。使用这些数据， 更合理的方法来设计毒性较小，更有效 β-淀粉样变性的抑制剂将通过与 医学院的科学家。