The variation of amyloid β peptide (Aβ) concentration and Aβ aggregation are closely associated with the etiology of Alzheimer’s diseases (AD). The interaction of Aβ with the monosialoganglioside-rich neuronal cell membrane has been suggested to influence Aβ aggregation. Therefore, studies on the mechanism of Aβ and sialic acids (SA) interaction would greatly contribute to better understanding the pathogenesis of AD. Herein, we report a novel approach for Aβ–SA interaction analysis and highly sensitive Aβ detection by mimicing the cell surface presentation of SA clusters through engineering of SA-modified peptide nanofiber (SANF). The SANF displayed well-ordered 1D nanostructure with high density of SA on surface. Using FAM-labeled Aβ fragments of Aβ1–16, Aβ16–23, and Aβ24–40, the interaction between Aβ and SA was evaluated by the fluorescence titration experiments. It was found that the order of the SA-binding affinity was Aβ1–16 > Aβ24–40 > Aβ16–23. Importantly, the presence of full-length Aβ1–40 monomer triggered a significant fluorescence enhancement due to the multivalent binding of Aβ1–40 to the nanofiber. This fluorescent turn-on response showed high selectivity and sensitivity for Aβ1–40 detection and the method was further used for Aβ aggregation process monitoring and inhibitor screening. The results suggest the proposed strategy is promising to serve as a tool for mechanism study and the early diagnosis of Alzheimer’s disease.
淀粉样β肽(Aβ)浓度的变化和Aβ的聚集与阿尔茨海默病(AD)的病因密切相关。Aβ 与富含单
唾液酸神经元细胞膜的相互作用被认为会影响 Aβ 的聚集。因此,研究Aβ与
硅铝酸(
SA)相互作用的机制将大大有助于更好地理解AD的发病机制。在此,我们报告了一种新的方法,即通过
SA修饰肽纳米纤维(
SANF)的工程设计模拟
SA团簇在细胞表面的呈现,来分析Aβ-
SA相互作用并进行高灵敏度的Aβ检测。这种
SANF 显示出表面高密度
SA 的有序一维纳米结构。利用 FAM 标记的 Aβ 片段 Aβ1-16、Aβ16-23 和 Aβ24-40,通过荧光滴定实验评估了 Aβ 与
SA 之间的相互作用。结果发现,Aβ与
SA的结合亲和力顺序为:Aβ1-16 > Aβ24-40 > Aβ16-23。重要的是,由于 Aβ1-40 与纳米纤维的多价结合,全长 Aβ1-40 单体的存在引发了显著的荧光增强。这种荧光开启响应显示了 Aβ1-40 检测的高选择性和高灵敏度,该方法被进一步用于 Aβ 聚集过程监测和
抑制剂筛选。结果表明,所提出的策略有望成为阿尔茨海默病机制研究和早期诊断的工具。