Elucidating the mechanism of amyloid-beta's pathological aggregation

阐明β淀粉样蛋白病理聚集机制

• 批准号: 8591174
• 负责人: Pieter Ernst Smith
• 金额: $ 4.72万
• 依托单位: WEIZMANN INSTITUTE OF SCIENCE
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8591174
• 关键词: Affect; Alzheimer' s Disease; Amyloid beta-Protein; Amyloid fibers; Autopsy; Behavior; Biological; Biological Models; Brain; Caregivers; Cell Culture Techniques; Cell Nucleus; Chemicals; Clinical; Data Set; Deposition; Detection; Development; Diffusion; Dimensions; Disease; Elderly; Employee Strikes; Environment; Equilibrium; Etiology; Evolution; Frequencies; Goals; Health; Homo; Human; In Vitro; Investigation; Laboratories; Life; Measurement; Measures; Medical; Methodology; Methods; Minority; Modification; Molecular; NMR Spectroscopy; Nature; Neurodegenerative Disorders; Nuclear; Onset of illness; Oocytes; Pathology; Patients; Peptides; Phenotype; Play; Process; Productivity; Property; Public Health; Quality of life; Radial; Relaxation; Role; Sampling; Scanning; Scheme; Severities; Signal Transduction; Site; Solutions; Speed; Staging; Structure; Symptoms; System; TOCSY; Techniques; Time; Transgenic Organisms; United States; Variant; Xenopus laevis; Xenopus oocyte; abeta accumulation; age related; aggregation pathway; aqueous; cognitive function; conformer; cytotoxicity; extracellular; in vivo; innovation; insight; interest; molecular size; monomer; mouse model; polymerization; research study; spectroscopic imaging; tool

DESCRIPTION (provided by applicant): Alzheimer's disease (AD), the most common neurodegenerative disorder, is an age-dependent disorder resulting in progressive loss of cognitive function. It affects more than 4 million people in the United States and is therefore a highly relevant factor in the elderly's quality of life. The symptoms of the disease strongly correlate with the presence of transiently formed and soluble aggregates of amyloid-beta (Aβ) in the brains of AD patients. Because of the relevance Alzheimer's to public health, there is substantial interest in understanding the molecular mechanism of AD and treating the disease. Nevertheless, the short-lived nature of the Aβ soluble intermediates formed during the course of its pathological aggregation presents a formidable challenge to the traditional techniques used for the investigation of biological molecules. Although progress has been made in studying these molecules, by making slight chemical modifications that increase their stability, for example, it is not known whether the molecular behavior observed in these studies is completely relevant to the behavior of Aβ in humans. In the Frydman lab techniques have been developed that allow the fast characterization of features of biological molecules relevant to thei behavior (structure and dynamics). We propose to use these techniques, a suite of ultrafast NMR experiments, to investigate the structure and dynamics of Aβ as it undergoes aggregation. Ultrafast TOCSY and STD-TOCSY experiments will be used to probe the interaction between Aβ monomers and oligomers during the aggregation process. The diffusive dynamics of the system will be probed by ultrafast DOSY experiments, which separates resonances according to the hydrodynamic radii associated with the chemical sites to which they belong. Further functional insights will also be gained from site-resolved longitudinal relaxation measurements, which reveal the mobility of molecular fragments-and hence their degree of polymerization. This proposal aims to uncover detailed structural information about Aβ's folded monomeric state, which is believed to play a crucial role in the formation of a nucleus for Aβ's aggregation. In aqueous solution, folded conformers of Aβ undergo conformational exchange with its random coil state. Using the innovative selective dynamic recoupling (SDR) technique that I have developed, the chemical shifts of folded Aβ conformers will be revealed, which can be used to probe their structures. The in vivo behavior of Aβ in a cellular environment is believed to play a significant role in its pathology. I plan to uncover detailed information on the intracellular behavior of Aβ by performing NMR experiments in living Xenopus laevis oocytes.

描述（由申请人提供）：阿尔茨海默病（AD）是最常见的神经退行性疾病，是一种导致认知功能进行性丧失的年龄依赖性疾病。它影响了美国400多万人，因此是老年人生活质量的一个高度相关因素。该疾病的症状与AD患者脑中淀粉样蛋白-β（Aβ）的瞬时形成和可溶性聚集体的存在密切相关。由于阿尔茨海默病与公共卫生的相关性，人们对理解AD的分子机制和治疗该疾病有很大的兴趣。然而，在其病理性聚集过程中形成的Aβ可溶性中间体的短暂性质对用于研究生物分子的传统技术提出了严峻的挑战。虽然在研究这些分子方面取得了进展，例如通过进行轻微的化学修饰来增加其稳定性，但尚不清楚这些研究中观察到的分子行为是否与人类中Aβ的行为完全相关。在Frydman实验室中，已经开发出允许快速表征与其行为（结构和动力学）相关的生物分子特征的技术。我们建议使用这些技术，一套超快NMR实验，研究Aβ的结构和动力学，因为它经历聚集。超快TOCSY和STD-TOCSY实验将用于探测聚集过程中Aβ单体和寡聚体之间的相互作用。该系统的扩散动力学将通过超快DOSY实验来探测，该实验根据与它们所属的化学位点相关的流体动力学半径来分离共振。进一步的功能性见解也将获得从现场解决纵向弛豫测量，这揭示了分子片段的流动性，因此他们的聚合度。该提案旨在揭示有关Aβ折叠单体状态的详细结构信息，这被认为在Aβ聚集的核形成中起着至关重要的作用。 在水溶液中，Aβ的折叠构象与其无规卷曲状态发生构象交换。使用创新的选择性动态再耦合（SDR）技术，我已经开发，折叠Aβ构象的化学位移将被揭示，这可以用来探测它们的结构。认为Aβ在细胞环境中的体内行为在其病理学中起重要作用。我计划通过在非洲爪蟾卵母细胞中进行核磁共振实验来揭示Aβ细胞内行为的详细信息。