Department of Biology and Chemistry, Paul Scherrer Institute, 5232, Villigen, Switzerland.
Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
Q Rev Biophys. 2020 Nov 5;53:e12. doi: 10.1017/S0033583520000086.
In neurodegenerative diseases, a wide range of amyloid proteins or peptides such as amyloid-beta and α-synuclein fail to keep native functional conformations, followed by misfolding and self-assembling into a diverse array of aggregates. The aggregates further exert toxicity leading to the dysfunction, degeneration and loss of cells in the affected organs. Due to the disordered structure of the amyloid proteins, endogenous molecules, such as lipids, are prone to interact with amyloid proteins at a low concentration and influence amyloid cytotoxicity. The heterogeneity of amyloid proteinscomplicates the understanding of the amyloid cytotoxicity when relying only on conventional bulk and ensemble techniques. As complementary tools, single-molecule techniques (SMTs) provide novel insights into the different subpopulations of a heterogeneous amyloid mixture as well as the cytotoxicity, in particular as involved in lipid membranes. This review focuses on the recent advances of a series of SMTs, including single-molecule fluorescence imaging, single-molecule force spectroscopy and single-nanopore electrical recording, for the understanding of the amyloid molecular mechanism. The working principles, benefits and limitations of each technique are discussed and compared in amyloid protein related studies.. We also discuss why SMTs show great potential and are worthy of further investigation with feasibility studies as diagnostic tools of neurodegenerative diseases and which limitations are to be addressed.
在神经退行性疾病中，广泛的淀粉样蛋白或肽，如淀粉样蛋白-β和α-突触核蛋白，无法保持其天然的功能构象，随后发生错误折叠并自行组装成各种聚集体。这些聚集体进一步发挥毒性，导致受影响器官的细胞功能障碍、退化和丧失。由于淀粉样蛋白的结构无序，内源性分子（如脂质）容易在低浓度下与淀粉样蛋白相互作用，并影响淀粉样蛋白的细胞毒性。淀粉样蛋白的异质性使得仅依赖常规的整体和组合技术来理解淀粉样蛋白细胞毒性变得复杂。作为补充工具，单分子技术（SMT）为了解异质淀粉样蛋白混合物的不同亚群以及细胞毒性（特别是涉及脂质膜时）提供了新的见解。本综述重点介绍了一系列 SMT 的最新进展，包括单分子荧光成像、单分子力谱和单纳米孔电记录，用于理解淀粉样蛋白的分子机制。讨论并比较了每种技术的工作原理、优点和局限性，并在与淀粉样蛋白相关的研究中进行了讨论。我们还讨论了为什么 SMT 显示出巨大的潜力，值得进一步研究，以及可行性研究作为神经退行性疾病的诊断工具，以及需要解决哪些局限性。
