茶多酚功能化柱芳烃超分子自组装体的构建及其对β-淀粉样蛋白纤维化的抑制作用

Alzheimer disease (AD) is a kind of disease that seriously affects human health. The misfolding of the beta-amyloid protein (Aβ) could result in the fibrillation, which is considered to be directly correlated to AD. Therefore, inhibition of the fibrillation of Aβ is considered to be one of the useful herapeutic methods for AD. It has been indicated that macrocyclic supramolecules (e.g. cucurbituril) and tea polyphenol both have the ability of inhibiting the formation of beta-amyloid protein fibrillation. Comparing with the typical macrocyclic supramolecules, pillararene has some merits. Furthermore, pillararene has the potential to form supramolecular self-assemblies, which may easily enter into cell. However, the inhibition ability of the fibrillation by pillararene or pillararene-based self-assembly has not been reported. In our preparatory experiment, we successfully synthesized pilla[5]rarene and found that the Aβ(1-40) fibrillation inhibition ability of pilla[5]rarene was appropriately 500 folds higher than that of cucur[7]bituril. Therefore, in the present project, we will propose to synthesize the tea polyphenol (EGCG)-functionalized amphipathic pilla[5]rarene (EGCG-AP5) and prepare EGCG-AP5 self-assembly, then investigate the inhibition ability of the fibrillation by EGCG-AP5 self-assembly using Aβ(1-40) and Aβ(1-42) as model amyloid proteins. Furthermore, we will reveal the inhibition mechanism of fibrillation by EGCG-AP5 self-assembly by using the results of host-guest molecular docking. The constructed self-assembly is expected to play double roles of EGCG and pillararene in inhibiting fibrillation of beta-amyloid protein by EGCG-AP5. The results will provide new thoughts and theoretical foundation for the research and development of efficient fibrillation inhibitor. Furthermore, the results may also provide helpful insights into prevention and treatment of AD, which may broaden the applications of pillararene in the biological field.

阿尔兹海默症（AD）是一种严重危害人类健康的疾病。大脑中β-淀粉样蛋白（Aβ）的错误折叠而致的纤维化与AD直接相关，因而抑制Aβ纤维化是治疗AD的一种方法。研究表明葫芦脲等大环超分子以及茶多酚均具有抑制Aβ纤维化的能力。与传统的大环超分子相比，柱芳烃彰显了许多性能上的优点，而且它可以在水溶液中形成自组装体有利于进入细胞。然而，柱芳烃及其自组装体对Aβ纤维化抑制的研究还未见报道。我们前期成功合成柱[5]芳烃，并发现其对Aβ纤维化的抑制能力是葫芦脲7的约500倍。为此，本项目拟合成茶多酚功能化的两亲性柱[5]芳烃并制备其自组装体，研究其在体外和细胞内对Aβ纤维化的抑制作用，考察茶多酚和柱芳烃对蛋白纤维化的双重抑制作用。同时，结合主客体分子模拟研究，揭示自组装体对蛋白纤维化的抑制机理。研究结果为Aβ纤维化高效抑制剂的研发提供理论依据，为AD药物的研发提供新思路。同时可拓宽柱芳烃在生物领域的应用。

阿尔兹海默症（AD）是一种严重危害人类健康的疾病，而抑制Aβ纤维化是治疗AD的一种方法。与传统的大环超分子相比，柱芳烃彰显了许多性能上的优点，而且它可以在水溶液中形成自组装体有利于进入细胞。然而，柱芳烃及其自组装体对Aβ纤维化抑制的研究还未见报道。本项目合成茶多酚功能化的两亲性柱[5]芳烃并制备其自组装体，研究其对Aβ纤维化的抑制作用，考察茶多酚和柱芳烃对蛋白纤维化的双重抑制作用。同时，结合主客体分子模拟研究，揭示自组装体对蛋白纤维化的抑制机理。在实际实验过程中，茶多酚功能化的氨基化柱[5]芳烃对Aβ纤维化抑制的效果并不理想，因此本项目重点开展柱[5]芳烃(AP5)对Aβ纤维化的抑制作用及其机理的研究。项目研究结果为：1）首先用分子模拟的方法阐明了柱[5]芳烃与Aβ的结合方式，模拟计算发现，静电相互作用是AP5 与Aβ40 结合形成复合物的主要驱动因素，其次为范德华力，阐明了氨基化柱[5]芳烃对Aβ肽纤维化的抑制机理；2）硫化素T荧光染料结合法测定纤维化的结果表明：氨基化柱[5]芳烃对Aβ肽纤维化有较为明显的抑制效果；3）透射电镜的原子力显微镜的研究结果表明：氨基化柱[5]芳烃的加入显著降低了Aβ肽的纤维化，以上研究结果为Aβ纤维化高效抑制剂的研发提供理论依据，为AD药物的研发提供新思路；4）在开展本研究的过程中，除了柱芳烃在抑制Aβ肽纤维化的功能之外，本课题组也把超分子识别也引入到光电化学传感器中，为其在传感方面的应用开辟了新领域，也取得了一系列可喜的研究进展，拓宽柱芳烃在生物领域的应用。值得一提的是，在新冠疫情爆发期间，本课题根据前期大环超分子对亚甲基蓝等电信号分子的有效识别和富集，开发了世界上首台新冠病毒核酸的电化学传感器，体现了学科之间的交叉和融合。项目实施期间，发表了论文16篇，其中SCI论文15篇，中文核心期刊1篇，获得授权专利10项。