National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China.
Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520, USA.
Molecules. 2021 Feb 11;26(4):948. doi: 10.3390/molecules26040948.
The misfolding and aggregation of polypeptide chains into β-sheet-rich amyloid fibrils is associated with a wide range of neurodegenerative diseases. Growing evidence indicates that the oligomeric intermediates populated in the early stages of amyloid formation rather than the mature fibrils are responsible for the cytotoxicity and pathology and are potentially therapeutic targets. However, due to the low-populated, transient, and heterogeneous nature of amyloid oligomers, they are hard to characterize by conventional bulk methods. The development of single molecule approaches provides a powerful toolkit for investigating these oligomeric intermediates as well as the complex process of amyloid aggregation at molecular resolution. In this review, we present an overview of recent progress in characterizing the oligomerization of amyloid proteins by single molecule fluorescence techniques, including single-molecule Förster resonance energy transfer (smFRET), fluorescence correlation spectroscopy (FCS), single-molecule photobleaching and super-resolution optical imaging. We discuss how these techniques have been applied to investigate the different aspects of amyloid oligomers and facilitate understanding of the mechanism of amyloid aggregation.
多肽链错误折叠和聚集形成β-折叠丰富的淀粉样纤维与广泛的神经退行性疾病有关。越来越多的证据表明，在淀粉样形成的早期阶段存在的寡聚中间体，而不是成熟的纤维，负责细胞毒性和病理学，并且可能是治疗靶点。然而，由于淀粉样寡聚体的低 populate、瞬态和异质性，它们很难用传统的批量方法来表征。单分子方法的发展为研究这些寡聚中间体以及淀粉样聚集的复杂过程提供了一个强大的工具包，在分子分辨率上。在这篇综述中，我们介绍了通过单分子荧光技术表征淀粉样蛋白寡聚化的最新进展，包括单分子荧光共振能量转移(smFRET)、荧光相关光谱(FCS)、单分子光漂白和超分辨率光学成像。我们讨论了这些技术如何被应用于研究淀粉样寡聚体的不同方面，并促进对淀粉样聚集机制的理解。
