Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
Anal Chem. 2013 Feb 19;85(4):2049-55. doi: 10.1021/ac303181q. Epub 2013 Jan 29.
A number of human protein misfolding disorders, including Alzheimer's disease (AD), are closely related to the accumulation of β-sheet-rich amyloid fibrils or aggregates. Neuronal toxicity in AD has been linked to the interactions of amyloid-β (Aβ) with metals, especially Zn(2+), Cu(2+), and Fe(3+), which leads to the production of reactive oxygen species. Nucleation-dependent Aβ aggregation, or "seeding", is thought to propagate fibril formation. In this surface plasmon resonance imaging (SPRi) study, we have shown that the fibril seeds formed with the incubation of Aβ in the presence of metals are better at promoting monomer elongation compared to Aβ alone or in the presence of a well-described polyphenol, (-)-epigallocatechin-3-gallate (EGCG). This is a novel attempt to simultaneously monitor the effects of multiple modulators on fibril elongation using a single chip. EGCG was shown in transmission electron microscopy (TEM) and thioflavin T (ThT) studies to promote the formation of off-pathway, highly stable unstructured oligomers, supporting the SPRi results. These findings suggest that SPRi provides a promising platform as a screening tool for small molecules that can affect the aggregation pathways in neurodegenerative diseases.
许多人类蛋白质错误折叠疾病，包括阿尔茨海默病（AD），与β-折叠丰富的淀粉样纤维或聚集体的积累密切相关。AD 中的神经元毒性与淀粉样-β（Aβ）与金属，特别是 Zn(2+)、Cu(2+)和 Fe(3+)的相互作用有关，这导致活性氧的产生。依赖于成核的 Aβ聚集或“接种”被认为可以传播纤维形成。在这项表面等离子体共振成像（SPRi）研究中，我们已经表明，与单独的 Aβ或在描述良好的多酚（(-)-表没食子儿茶素没食子酸酯（EGCG））存在下孵育 Aβ 形成的纤维种子更能促进单体伸长。这是一种使用单个芯片同时监测多种调节剂对纤维伸长影响的新尝试。在透射电子显微镜（TEM）和硫黄素 T（ThT）研究中，EGCG 被证明能促进形成偏离途径的、高度稳定的无结构低聚物，这支持了 SPRi 的结果。这些发现表明，SPRi 为小分子提供了一个有前途的筛选工具平台，这些小分子可以影响神经退行性疾病中的聚集途径。
