Structural Studies of Alzheimer's beta-Amyloid Fibrils

阿尔茨海默病 β-淀粉样原纤维的结构研究

• 批准号: 9148762
• 负责人: ROBERT TYCKO
• 金额: $ 46.36万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 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/9148762
• 关键词: Alzheimer' s Disease; Amyloid; Amyloid Fibrils; Amyloid beta-Protein; Area; Autopsy; Brain; Categories; Collaborations; Data; Data Analyses; Electron Microscopy; Genetic Polymorphism; Goals; Growth; Label; Lead; London; Manuscripts; Molecular; Molecular Structure; Nuclear; Patients; Process; Protocols documentation; Publishing; Recording of previous events; Reporting; Staging; Structure; Tissue Sample; Universities; Work; Writing; amyloid formation; base; beta pleated sheet; brain tissue; cerebral atrophy; cold temperature; college; neurotoxicity; neutrophil; physical chemical interaction; research study; self assembly; solid state nuclear magnetic resonance

Progress in FY2015 has been in the following areas: (1) AMYLOID FIBRIL STRUCTURES DERIVED FROM BRAIN TISSUE: In collaboration with Prof. John Collinge of University College London, we have obtained solid state NMR and electron microscopy data for fibrils derived from 36 brain tissue samples from autopsies of AD patients in four categories (typical long history, posterior cortical atrophy, short duration, nondemented). Using our published amyloid extraction and seeding protocols, isotopically labeled fibrils were prepared using both 40-residue and 42-residue beta-amyloid peptides. The solid state NMR data suggest that most AD patients develop the same predominant 40-residue fibril structure in their brains, but that short duration patients can develop different and more heterogeneous structures. Results for 42-residue fibrils indicate no clear correlation between patient category and molecular structure. We have explored various approaches to data analysis, and are now in the process of writing a manuscript to report these results. (2) SOLID STATE NMR STUDIES OF THE BETA-AMYLOID ASSEMBLY PROCESS: We have used solid state NMR to examine the progression of conformational changes and changes in supramolecular organization as the beta-amyloid peptide goes from a monomeric state to an oligomeric state to a protofibrillar state and finally to a true amyloid fibril state. These experiments are enabled by the low-temperature dynamic nuclear polarization apparatus developed in our lab. We find that the principal conformational features (two separate beta-strand segments) are present even at the earliest stages of self-assembly, but that the degree of conformational order increases monotonically. Moreover, the in-register parallel beta-sheet structure does not appear until the final amyloid fibril state. This work has been published in J. Am. Chem. Soc.

2015财年在以下方面取得了进展： (1)来源于脑组织的淀粉样纤维结构：我们与伦敦大学学院的John Colinger教授合作，从AD患者尸检的四个类别(典型的长病史、皮质后萎缩、持续时间短、非痴呆)的36个脑组织样本中获得了固态核磁共振和电子显微镜的纤维数据。使用我们发表的淀粉样蛋白提取和播种方案，用40-残基和42-残基的β-淀粉样多肽制备了同位素标记的纤维。固态核磁共振数据表明，大多数AD患者在他们的大脑中发展了相同的40个残基的纤维结构，但短期患者可以发展不同的和更不同的结构。对42-残基纤维的结果表明，患者类别和分子结构之间没有明显的相关性。我们已经探索了各种数据分析方法，目前正在撰写报告这些结果的手稿。 (2)β-淀粉样蛋白组装过程的固体核磁共振研究：我们使用固体核磁共振研究了当β-淀粉样多肽从单体状态到寡聚态再到原纤维状态，最后到真正的淀粉样原纤维状态时，构象变化和超分子组织的变化。这些实验是由我们实验室研制的低温动态核极化装置实现的。我们发现，即使在自组装的最早阶段，主要的构象特征(两个单独的β-链段)也存在，但构象有序度单调增加。此外，寄存器中的平行β-折叠结构直到最终的淀粉样原纤维状态才出现。这项研究发表在《J.Am》杂志上。化学。SoC。