Intermediate States of Aggregation-Prone Polypeptides

易聚集多肽的中间状态

• 批准号: 7568877
• 负责人: DARYL K EGGERS
• 金额: $ 13.07万
• 依托单位: SAN JOSE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7568877
• 关键词: Accounting; Alzheimer' s Disease; Amides; Amyloid; Biomedical Research; Calorimetry; Characteristics; Circular Dichroism Spectroscopy; Condition; Disease; Encapsulated; Environment; Equilibrium; Event; Free Energy; Gel; Glass; Goals; Higher Order Chromatin Structure; Huntington Disease; Hydration status; Laboratories; Lead; Link; Measurement; Modeling; Molecular Conformation; Monitor; Muramidase; Numbers; Parkinson Disease; Peptide Fragments; Phase; Preclinical Drug Evaluation; Prions; Prohibit; Protein Conformation; Proteins; Research; Silicon Dioxide; Solubility; Solutions; Solvents; Superoxide Dismutase; Techniques; Testing; Therapeutic Intervention; Thermodynamics; Variant; Vertebral column; Water; Yeasts; alpha synuclein; aqueous; density; human disease; intermolecular interaction; polypeptide; protein aggregation; protein folding; protein misfolding; solute

In the past decade, protein folding has gained wider recognition and acceptance as an important field of biomedical research due, in part, to the growing number of examples of protein misfolding that have been linked to human diseases. In most cases, the misfolding event results in the formation of intermolecular aggregates and higher-ordered structures, often leading to the characteristic plaques known as amyloid. One aim of this research is to monitor the changes in protein conformation that precede aggregation in a unique environment where intermolecular interactions are prohibited. This will be achieved by encapsulating aggregation-prone polypeptides in the pores of a silica glass matrix by the sol-gel technique. Once encapsulated, solvent conditions will be altered to mimic those conditions that favor aggregation in solution. Circular dichroism spectroscopy will be used to detect intermediate states that differ in conformation from both the native and aggregated states of each protein and to screen for drug candidates or solutes that destabilize the intermediate conformation. Lysozyme, alpha-synuclein, a peptide fragment from the yeast prion Sup35, and a disease-associated variant of CuZn-superoxide dismutase will be among the first polypeptides studied by this approach. A second major aim of this research is to determine whether unfavorable backbone hydration serves as a dominant force in aggregation of misfolded proteins. This goal involves the testing of a new thermodynamic framework, developed by this laboratory, that accounts for the participation of bulk water in aqueous equilibria. A combination of density measurements and calorimetry techniques will be used to calculate the free energy of the bulk aqueous phase in the presence of specific solutes. Calorimetry studies will be followed by solubility measurements of model amide-containing compounds to elucidate the magnitude of backbone solvation energetics in protein folding and aggregation. This project aims to further our understanding of factors that promote protein aggregation. This research could lead to new strategies for therapeutic intervention of diseases caused by misfolding of proteins, including Alzheimer's, Parkinson's, and Huntington's diseases.

在过去的十年里，蛋白质折叠作为一个重要的领域得到了广泛的认可和接受 生物医学研究部分归因于越来越多的蛋白质错误折叠的例子 与人类疾病有关。在大多数情况下，错误折叠事件导致分子间的形成 聚集体和更高有序的结构，通常导致被称为淀粉样蛋白的特征斑块。一 这项研究的目的是监测在凝聚之前蛋白质构象的变化 禁止分子间相互作用的环境。这将通过封装 用溶胶-凝胶法在二氧化硅玻璃基质的孔隙中聚集的多肽。一次 封装的溶剂条件将被改变，以模拟那些有利于在溶液中聚集的条件。 圆二色谱将用于检测构象不同的中间态 每种蛋白质的天然状态和聚集状态，并筛选候选药物或 破坏中间构象的稳定性。溶菌酶，α-突触核蛋白，酵母中的一种多肽片段 Prion Sup35和一种与疾病相关的CuZn-超氧化物歧化酶变体将是第一批 用这种方法研究的多肽。 这项研究的第二个主要目的是确定不利的脊椎水化是否可以作为 错误折叠的蛋白质聚集的主导力量。这一目标包括测试一种新的热力学 由该实验室开发的框架，该框架解释了散装水在水溶液中的参与 均衡。密度测量和量热技术的组合将被用来计算 在特定溶质存在的情况下，主体水相的自由能。量热研究将会是 然后是模型含酰胺化合物的溶解度测量，以阐明 蛋白质折叠和聚集中的主链溶剂化能量学。 这个项目旨在加深我们对促进蛋白质聚集的因素的理解。这项研究 可能为蛋白质错误折叠引起的疾病的治疗干预带来新的策略， 包括阿尔茨海默氏症、帕金森氏症和亨廷顿氏症。