Koh Moonjee, Lee Hwiin, Lee Youmin, Lee Minyung
J Nanosci Nanotechnol. 2014 Nov;14(11):8386-9. doi: 10.1166/jnn.2014.9923.
Amyloid-β (Aβ) oligomers are nanosized bio-assemblies that cause Alzheimer's disease. Characterizing early-stage Aβ aggregates becomes an important issue because it is a prerequisite in exploring small molecule inhibitors that bind to Aβ oligomers. Of special interest are efficient screening systems that characterize the Aβ oligomer size with respect to the aging time. In this work, highly sensitive fluorescence techniques and atomic force microscopy (AFM) were employed to investigate the size determination of Aβ and screening of small molecule inhibitors. A solvatochromic dye, 1-anilinonaphthalene-8-sulfonic acid (ANS), was used as an extrinsic fluorophore to monitor the growth mechanism of the Aβ aggregates. Then, the time-resolved fluorescence anisotropy method was employed to estimate the hydrodynamic size of Aβ oligomers. Finally, AFM was used to characterize the Aβ oligomer size in the absence and presence of potential inhibitors. We present that the combination of such three experimental techniques is an excellent way to detect the early stage of Aβ aggregation and to screen small molecule inhibitors.
淀粉样β蛋白（Aβ）寡聚体是导致阿尔茨海默病的纳米级生物聚集体。表征早期Aβ聚集体成为一个重要问题，因为这是探索与Aβ寡聚体结合的小分子抑制剂的先决条件。特别令人感兴趣的是能够根据老化时间表征Aβ寡聚体大小的高效筛选系统。在这项工作中，采用高灵敏度荧光技术和原子力显微镜（AFM）来研究Aβ的大小测定和小分子抑制剂的筛选。一种溶剂化显色染料，1-苯胺基萘-8-磺酸（ANS），被用作外在荧光团来监测Aβ聚集体的生长机制。然后，采用时间分辨荧光各向异性方法来估计Aβ寡聚体的流体动力学大小。最后，利用AFM在存在和不存在潜在抑制剂的情况下表征Aβ寡聚体大小。我们提出，这三种实验技术的结合是检测Aβ聚集早期阶段和筛选小分子抑制剂的极佳方法。
