化皮带的结构特征是电子显微镜,原子力显微镜和固态核磁共振
Kent R Thurber1, Wai-Ming Yau1, Robert Tycko1
1Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States.
The journal of physical chemistry. B
|February 13, 2024
概括
由阿尔茨海默病相关的粉样蛋白-β片段形成的粉样蛋白丝带具有交叉β结构. 它们的生长方向与键对齐,厚度取决于β片宽度和可变宽度取决于堆叠的β片.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 神经科学是一个神经科学.
背景情况:
- 多可以自组装成具有跨β结构的粉样纤维.
- 粉样体碎片可以形成带状组件,具有不同的形态.
- 与阿尔茨海默病相关的粉样β (Aβ) 参与纤维细胞的形成.
研究的目的:
- 研究由Aβ14-23和Aβ11-25形成的粉样带的详细结构.
- 阐明分子结构和带形态学之间的关系.
主要方法:
- 固态核磁共振 (ssNMR) 用于β-sheet注册和结合.
- 暗场传输电子显微镜 (TEM) 用于每面积质量测定.
- 原子力显微镜 (AFM) 用于带厚度测量.
- 低温电子显微镜 (cryoEM) 用于β-片间距分析.
主要成果:
- ssNMR数据显示了具有特定分子间键注册表的反平行β片.
- 飞行机组确认了约5nm的一致带厚度.
- 低温EM显示了Aβ14-23丝带内β-片的周期间隔.
- 每面积质量值是从TEM数据中得出的.
结论:
- 粉样带的生长沿着β-链之间的分子间键的方向发生.
- 带的厚度与单个β片的宽度相对应.
- 变量带宽的结果是 β-sheet 堆叠重复距离的倍数.
- 这种交叉β架构可能在粉样带中很常见.
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