Sang Jason C, Lee Ji-Eun, Dear Alexander J, De Suman, Meisl Georg, Thackray Alana M, Bujdoso Raymond, Knowles Tuomas P J, Klenerman David
Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge , CB2 1EW , UK . Email:
Department of Veterinary Medicine , University of Cambridge , Madingley Road , Cambridge , CB3 0ES , UK.
Chem Sci. 2019 Mar 25;10(17):4588-4597. doi: 10.1039/c8sc05627g. eCollection 2019 May 7.
The aggregation of the prion protein (PrP) plays a key role in the development of prion diseases. In the past decade, a similar process has been associated with other proteins, such as Aβ, tau, and α-synuclein, which participate in other neurodegenerative diseases. It is increasingly recognized that the small oligomeric species of aggregates can play an important role in the development of prion diseases. However, determining the nature of the oligomers formed during the aggregation process has been experimentally difficult due to the lack of suitable methods capable of the detection and characterization of the low level of oligomers that may form. To address this problem, we have utilized single-aggregate methods to study the early events associated with aggregation of recombinant murine PrP to approach the bona fide process . PrP aggregation resulted in the formation of thioflavin T (ThT)-inactive and ThT-active species of oligomers. The ThT-active oligomers undergo conversion from a Proteinase K (PK)-sensitive to PK-resistant conformer, from which mature fibrils can eventually emerge. Overall, our results show that single-aggregate methods can provide structural and mechanistic insights into PrP aggregation, identify the potential species that mediates cytotoxicity, and reveal that a range of distinct oligomeric species with different properties is formed during prion protein aggregation.
朊病毒蛋白（PrP）的聚集在朊病毒疾病的发展中起关键作用。在过去十年中，类似的过程已与其他蛋白质相关联，如Aβ、tau和α-突触核蛋白，它们参与其他神经退行性疾病。人们越来越认识到，聚集体的小寡聚体物种在朊病毒疾病的发展中可发挥重要作用。然而，由于缺乏能够检测和表征可能形成的低水平寡聚体的合适方法，确定聚集过程中形成的寡聚体的性质在实验上一直很困难。为了解决这个问题，我们利用单聚集体方法来研究与重组小鼠PrP聚集相关的早期事件，以接近真实过程。PrP聚集导致形成硫黄素T（ThT）无活性和ThT活性的寡聚体物种。ThT活性寡聚体经历从蛋白酶K（PK）敏感构象到PK抗性构象的转变，最终可从中出现成熟的纤维。总体而言，我们的结果表明，单聚集体方法可以提供关于PrP聚集的结构和机制见解，识别介导细胞毒性的潜在物种，并揭示在朊病毒蛋白聚集过程中形成了一系列具有不同性质的独特寡聚体物种。
