Intermediate States of Aggregation-Prone Polypeptides

易聚集多肽的中间状态

• 批准号: 7753183
• 负责人: DARYL K EGGERS
• 金额: $ 18.68万
• 依托单位: SAN JOSE STATE UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7753183
• 关键词: Accounting; Alzheimer' s Disease; Amides; Amyloid; Biomedical Research; Calorimetry; Characteristics; Circular Dichroism Spectroscopy; 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; Parkinson Disease; Peptide Fragments; Phase; Protein Conformation; Proteins; Research; Silicon Dioxide; Solubility; Solutions; Solvents; Superoxide Dismutase; Techniques; Testing; Therapeutic Intervention; Thermodynamics; Universities; Variant; Vertebral column; Water; alpha synuclein; aqueous; density; drug candidate; human disease; intermolecular interaction; polypeptide; programs; protein aggregation; protein folding; protein misfolding; solute; sup35; yeast prion

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.

在过去的十年中，蛋白质折叠作为一个重要领域获得了更广泛的认可和接受。 生物医学研究的部分原因是蛋白质错误折叠的例子越来越多 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形成 聚集体和高阶结构，通常会导致称为淀粉样蛋白的特征性斑块。一 这项研究的目的是监测以独特的方式聚集之前蛋白质构象的变化 禁止分子间相互作用的环境。这将通过封装来实现 通过溶胶-凝胶技术在二氧化硅玻璃基质的孔中易于聚集的多肽。一次 封装后，溶剂条件将被改变以模拟有利于溶液中聚集的条件。 圆二色光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，并筛选候选药物或溶质 使中间构象不稳定。溶菌酶，α-突触核蛋白，来自酵母的肽片段 朊病毒 Sup35 和与疾病相关的 CuZn 超氧化物歧化酶变体将是首批研究对象之一 通过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主链水合作用是否可以作为 错误折叠蛋白质聚集的主导力量。这个目标涉及测试新的热力学 该实验室开发的框架解释了散装水在水体中的参与 平衡。将使用密度测量和量热技术的组合来计算 特定溶质存在下主体水相的自由能。量热研究将 随后测量模型含酰胺化合物的溶解度，以阐明溶解度的大小 蛋白质折叠和聚集中的主链溶剂化能量学。 该项目旨在进一步了解促进蛋白质聚集的因素。这项研究 可能会导致治疗干预由蛋白质错误折叠引起的疾病的新策略， 包括阿尔茨海默病、帕金森病和亨廷顿病。