从单个蛋白质中形成可逆或不可逆的粉样纤维的结构性理由
Lukas Frey1, Jiangtao Zhou2, Gea Cereghetti3,4
1Institute of Molecular Physical Science, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich, Switzerland.
Nature communications
|September 30, 2024
概括
不可逆转的粉样蛋白形成稳定的跨β结构,需要完整的蛋白质展开. 然而,可逆的粉样蛋白保留了一些原生结构,从而导致较不有序的聚合物.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 生物物理学的生物物理.
背景情况:
- 蛋白质错误折叠和聚合成粉样蛋白与疾病有关.
- 可逆性和不可逆性粉样蛋白之间的区别在分子层面上不太清楚.
- 粉样蛋白形成涉及交叉β动机,但存在结构变异.
研究的目的:
- 阐明可逆性和不可逆性粉样蛋白之间的原子层结构差异.
- 为了确定分子起源,区分可逆和不可逆的粉样蛋白形成.
- 为了研究蛋白质前体结构在粉样蛋白稳定性中的作用.
主要方法:
- 电子显微镜 (cryo-EM) 用于纤维的高分辨率结构确定.
- 固态核磁共振 (ssNMR) 谱学用于对可逆性粉样蛋白的分子洞察.
- 原子力显微镜 (AFM) 作为结构和生物物理分析的补充.
主要成果:
- 人类不可逆转的lyszyme粉样蛋白呈现出正规的交叉β片结构 (2.8 Å分辨率).
- 可逆性粉样蛋白显示出β片和螺旋结构的混合,保留了部分原生蛋白质构造.
- 不可逆转的蛋白色酶粉样蛋白也表现出正规的跨β折叠 (3.2 Å分辨率).
- 蛋白质前体的完全展开是不可逆转的粉样纤维素形成所必需的.
结论:
- 独特的折叠图案区分了来自同一蛋白质序列的可逆性和不可逆性粉样蛋白.
- 不可逆转的粉样蛋白形成需要完全转换原生蛋白质到跨β结构.
- 可逆性粉样蛋白保留了原始状态的"记忆",这有助于它们的结构和可逆性不那么有序.
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