Adewoye Anjola, Ezeigbo Ephraim, Vo Quan H, Legleiter Justin
The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States.
Department of Biochemistry and Molecular Biology, University of Nevada, 1664 N. Virginia Street, Reno, Nevada 89557, United States.
Biochemistry. 2025 Aug 19;64(16):3610-3622. doi: 10.1021/acs.biochem.5c00290. Epub 2025 Aug 6.
Several peptides derived from the SARS-CoV-2 spike protein (S-protein) are amyloidogenic, suggesting a potential role in COVID-19 disease-associated pathogenesis. Many disease-related amyloids form a variety of intermediate oligomeric aggregates and directly damage lipid membranes. Gain of toxic function is commonly observed for oligomeric and fibrillar aggregates of amyloid peptides. Therefore, the ability of four S-protein-derived peptides (s192, s258, s601, and s1166) to form oligomers and fibrils was investigated. Additionally, their ability to bind and damage lipid membranes was also determined. Using ThT assays, time points before and after fibril nucleation were chosen for each peptide to explore aggregate morphologies. At early time points, each peptide formed oligomers with unique morphological characteristics. Fibril morphologies of each peptide varied as well, with s601 and s1166 forming two distinct fibril morphologies that coexisted. When supported total brain lipid extract (TBLE) bilayers were exposed to S-protein-derived peptides and tracked via AFM, only s192 progressively bound to and damaged the membrane. Oligomers of s1166 formed on TBLE bilayers but did not visibly disrupt the bilayer. Both the s258 and s601 minimally (if at all) interacted with the bilayers. No fibrils were observed on the bilayers from any of the peptides. The addition of Ca to the assay reduced the ability of all peptides to bind to TBLE bilayers. As oligomer toxicity and membrane damage are common features of amyloid-based diseases, these results open the possibility that similar molecular mechanisms associated with the endoproteolysis of the SARS-CoV-2 S-protein may contribute to COVID-19.
几种源自严重急性呼吸综合征冠状病毒2（SARS-CoV-2）刺突蛋白（S蛋白）的肽具有淀粉样变性，这表明其在与冠状病毒病（COVID-19）相关的发病机制中可能发挥作用。许多与疾病相关的淀粉样蛋白会形成多种中间寡聚聚集体，并直接损伤脂质膜。淀粉样肽的寡聚体和纤维状聚集体通常具有毒性功能。因此，研究了四种源自S蛋白的肽（s192、s258、s601和s1166）形成寡聚体和纤维的能力。此外，还测定了它们结合和损伤脂质膜的能力。使用硫黄素T（ThT）分析，为每种肽选择纤维成核前后的时间点，以探索聚集体形态。在早期时间点，每种肽都形成了具有独特形态特征的寡聚体。每种肽的纤维形态也各不相同，s601和s1166形成了两种共存的不同纤维形态。当将支持的全脑脂质提取物（TBLE）双层膜暴露于源自S蛋白的肽并通过原子力显微镜（AFM）进行跟踪时，只有s192逐渐结合并损伤膜。s1166的寡聚体在TBLE双层膜上形成，但没有明显破坏双层膜。s258和s601与双层膜的相互作用最小（如果有的话）。在任何肽的双层膜上均未观察到纤维。在分析中添加钙降低了所有肽与TBLE双层膜结合的能力。由于寡聚体毒性和膜损伤是淀粉样蛋白相关疾病的共同特征，这些结果表明，与SARS-CoV-2 S蛋白内切蛋白水解相关的类似分子机制可能导致COVID-19。
