Solid state NMR of prion peptides

朊病毒肽的固态核磁共振

• 批准号: 6578746
• 负责人: DAVID E WEMMER
• 金额: $ 28.58万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6578746
• 关键词: bioimaging /biomedical imaging; chemical aggregate; chemical models; conformation; nuclear magnetic resonance spectroscopy; prions; protein structure function; stable isotope; structural biology

The focal point of the efforts for the next years will be to apply solid state NMR to peptides from the prion protein to biologically active aggregate states. We will begin with the "beta" form of the mouse 89-143 peptide containing the P101L mutation, which has been found to stimulate disease in transgenic mice. The inactive helical and coil states of the same peptide will be used for comparison to help identify conformational differences that may relate to the activity. We will also investigate the internal deletion peptide sPrP61, which is myrstylated at the C-terminal residue to mimic the GPI anchor. This peptide also forms ordered aggregates, but unlike the P101L peptide becomes protease resistant, analogous to PrPSc. We will try to generate magnetically ordered samples of fibrils of the peptides (analogous to what has been done for fiber diffraction), which would provide more structural information than available in unordered "powder" samples. We will also explore block- labeled peptides (full labeling for a contiguous set of amino acids) for local structure analysis. We will finish ongoing calibrations for using chemical shielding for determination of phi and psi angles and analyze the extent to which x1 affects analysis and/or can be independently determined. If methods for preparing PrPSc in vitro become available we will prepare specifically labeled samples to compare with the peptide models that have been studied.

未来几年的工作重点是将固态核磁共振应用于从朊病毒蛋白到生物活性聚集态的肽。我们将从含有 P101L 突变的小鼠 89-143 肽的“β”形式开始，该突变已被发现会刺激转基因小鼠患病。相同肽的非活性螺旋和卷曲状态将用于比较，以帮助识别可能与活性相关的构象差异。我们还将研究内部缺失肽 sPrP61，它在 C 端残基处被十四烷基化以模拟 GPI 锚。该肽也形成有序聚集体，但与 P101L 肽不同，它具有蛋白酶抗性，类似于 PrPSc。我们将尝试生成肽原纤维的磁性有序样品（类似于纤维衍射所做的），这将提供比无序“粉末”样品更多的结构信息。我们还将探索用于局部结构分析的块标记肽（对一组连续的氨基酸进行完全标记）。我们将完成使用化学屏蔽来确定 phi 和 psi 角度的持续校准，并分析 x1 影响分析和/或可以独立确定的程度。如果体外制备 PrPSc 的方法可用，我们将制备专门标记的样品，以与已研究的肽模型进行比较。