α-Helical Motif as Inhibitors of Toxic Amyloid-β Oligomer Generation via Highly Specific Recognition of Amyloid Surface

• Published in: iScience Vol. 17; pp. 87 - 100
• Main Authors: Jiang, Yixiang, Jiang, Xuehan, Shi, Xiaodong, Yang, Fadeng, Cao, Yang, Qin, Xuan, Hou, Zhanfeng, Xie, Mingsheng, Liu, Na, Fang, Qi, Yin, Feng, Han, Wei, Li, Zigang
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 26.07.2019; Elsevier
• Subjects: Biochemistry; Bioorganic Chemistry; Computational Chemistry; Biochemistry; Bioorganic Chemistry; Computational Chemistry
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2019.06.022

Amyloid fibril surfaces can convert soluble proteins into toxic oligomers and are attractive targets for intervention of protein aggregation diseases. Thus far, molecules identified with inhibitory activity are either large proteins or flat cyclic compounds lacking in specificity. The main design difficulty is flatness of amyloid surfaces and the lack of knowledge on binding interfaces. Here, we demonstrate, for the first time, a rational design of alpha-helical peptide inhibitors targeting the amyloid-beta 40 (Aβ40) fibril surfaces, based on our in silico finding that a helical fragment of Aβ40 interacts in a unique way with side-chain arrays on the fibril surface. We strengthen the fragment's binding capability through mutations and helicity enhancement with our Terminal Aspartic acid strategy. The resulting inhibitor shows micromolar affinity for the fibril surface, effectively impedes the surface-mediated oligomerization of Aβ40, and mitigates its cytotoxicity. This work opens up an avenue to designing aggregation modulators for amyloid diseases. [Display omitted] •Demonstrating that alpha-helical motif specifically recognizes Aβ amyloid surface•In silico structure-based design of peptides as PPI blockers•Disrupting Aβ-fibril interaction to prevent toxic oligomer formation Bioorganic Chemistry; Computational Chemistry; Biochemistry