Rapid Detection of Aβ Aggregation and Inhibition by Dual Functions of Gold Nanoplasmic Particles: Catalytic Activator and Optical Reporter
Rapid Detection of Aβ Aggregation and Inhibition by Dual Functions of Gold Nanoplasmic Particles: Catalytic Activator and Optical Reporter
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DOI：
10.1021/nn402310c
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发表时间：
2013-07-01
期刊：
影响因子：
17.1
通讯作者：
Lee, Luke P.
中科院分区：
文献类型：
--
作者：
Choi, Inhee;Lee, Luke P.
阿尔茨海默病 (AD) 的主要病理特征之一是淀粉样蛋白 -β (Aβ) 聚集及其细胞外积累。然而，目前的体外 Aβ 聚集测定需要耗时且费力的步骤，这延迟了药物发现和理解 Aβ 诱导神经毒性机制的过程。在这里，我们提出了一种快速检测方法，通过金纳米等离子体颗粒（GNP）的双重功能：（1）催化激活剂和（2）光学报告基因，在优化的酸性扰动条件下研究 Aβ 聚集和抑制。由于 GNP 作为快速催化 A β 聚集的有效成核位点和跟踪 A β 聚集的比色光学报告基因的作用，我们在不到 1 分钟的时间内通过肉眼完成了快速聚集测定。我们的检测方法基于未结合（未修饰）GNP 的自发聚类以及聚集促进条件下的聚集 A beta 网络。作为概念验证演示，我们采用酸性扰动，允许 GNP 和 A β 肽通过表面电荷调节快速协同组装。在 pH 2 至 3 左右的优化酸性扰动条件下，我们表征了生理相关 Aβ 浓度水平（从 100 μM 至 10 nM）下聚集的浓度依赖性比色响应。我们还通过使用众所周知的结合试剂（例如抗体和血清白蛋白）演示了基于 GNP/酸性条件的 Aβ 聚集快速抑制测定。所提出的方法可以成为筛选 AD 药物以及研究蛋白质聚集的分子生物物理学的强大替代方法，并进一步扩展到探索其他蛋白质构象疾病，例如神经退行性疾病。
One of the primary pathological hallmarks of Alzheimer's diseases (AD) is amyloid-beta (A beta) aggregation and its extracellular accumulation. However, current in vitro A beta aggregation assays require time-consuming and labor-intensive steps, which delay the process of drug discovery and understanding the mechanism of A beta induced neurotoxicity. Here, we propose a rapid detection method for studying A beta aggregation and inhibition under an optimized acidic perturbation condition by dual functions of gold nanoplasmonic particles (GNPs): (1) catalytic activator and (2) optical reporter. Because of roles of GNPs as effective nucleation sites for fast-catalyzing A beta aggregation and colorimetric optical reporters for tracking A beta aggregation, we accomplished the fast aggregation assay in less than 1 min by the naked eyes. Our detection method is based on spontaneous clustering of unconjugated (unmodified) GNPs along with the aggregated A beta network under an aggregation-promoting condition. As a proof-of-concept demonstration, we employed the acidic perturbation permitting rapid cooperative assemblies of GNPs and A beta peptides via their surface charge modulation. Under the optimized acidic perturbation condition around pH 2 to 3, we characterized the concentration-dependent colorimetric responses for aggregation at physiologically relevant A beta concentration levels (from 100 mu M to 10 nM). We also demonstrated the GNP/acidic condition-based rapid inhibition assay of A beta aggregation by using well-known binding reagents such as antibody and serum albumin. The proposed methodology can be a powerful alternative method for screening drugs for AD as well as studying molecular biophysics of protein aggregations, and further extended to explore other protein conformational diseases such as neurodegenerative disease.