Following the Aggregation of Human Prion Protein on Heparin Functionalized Gold Surface in Real Time
Following the Aggregation of Human Prion Protein on Heparin Functionalized Gold Surface in Real Time
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DOI：
10.1021/acsabm.2c00779
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发表时间：
2022-10-13
影响因子：
4.7
通讯作者：
Xu，Bingqian
中科院分区：
文献类型：
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作者：
Zhang，Tong;Pan，Yangang;Xu，Bingqian
朊病毒蛋白（PrP）的聚集在朊病毒疾病的发展中起着关键作用，并且被认为是具有非常高的动力学屏障的自催化过程。深入研究的重点是通过改变金、云母和脂质双层等固体表面上 PrP 溶液的 pH 值来克服极其非生理的体外条件下的动力学障碍。重要的是，硫酸化糖胺聚糖 (GAG)，包括肝素，被发现与 PrP 错误折叠和聚集有关，表明 GAG 在 PrP 聚集过程中具有催化作用。然而，GAG 在 PrP 聚集中的确切作用和细节尚不清楚，需要仔细研究。在这里，我们通过单分子原子力显微镜（AFM）结合同步形貌和识别（TREC）成像和单分子力谱（SMFS）原位实时监测整个聚集过程的原子尺度细节，研究了肝素功能化金表面上的PrP聚集过程。我们观察了全长人重组PrP（23-231）在肝素修饰金表面上聚集的整个聚集过程，从寡聚物的形成，到原纤维和短纤维的组装，再到细长成熟纤维的形成。研究发现肝素可通过促进早期成核阶段低聚物的形成来促进 PrP 聚集。
The aggregation of the prion protein (PrP) plays a key role in the development of prion diseases and is believed to be an autocatalytic process with a very high kinetic barrier. Intensive studies have focused on overcoming the kinetic barriers under extremely nonphysiological in vitro conditions by altering the pH of PrP solution on solid surfaces, such as gold, mica, and a lipid bilayer. Importantly, sulfated glycosaminoglycans (GAGs), including heparin, were found to be associated with PrP misfolding and aggregation, suggesting GAGs have catalytic roles in PrP aggregation processes. However, the exact role and details of GAGs in the PrP aggregation are not clear and need a thorough perusal. Here, we investigate the PrP aggregation process on a heparin functionalized gold surface by in situ, real-time monitoring of the atomic scale details of the whole aggregation process by single molecule atomic force microscopy (AFM), combining simultaneous topographic and recognition (TREC) imaging and single molecule force spectroscopy (SMFS). We observed the whole aggregation process for full-length human recombinant PrP (23–231) aggregation on the heparin modified gold surface, from the formation of oligomers, to the assembly of protofibrils and short fibers, and the formation of elongated mature fibers. Heparin is found to promote the PrP aggregation by facilitating the formation of oligomers during the early nucleation stage.