Electric Field Effect on Inhibiting the Co-fibrillation of Amyloid Peptides by Modulating the Aggregation Pathway

With the revelation of the close link between Alzheimer's disease (AD) and type II diabetes (T2D) and the possible assembly of multiple amyloid peptides therein, it is critical to understand and regulate the co-fibrillation pathway between related amyloid peptides. Here, we show experimentally and theoretically that electric field (EF) inhibited hybrid amyloid fibrillation of β-amyloid peptide (Aβ) and human islet amyloid peptide (hIAPP) by modulating the hetero-aggregation pathway. Experimental results confirm that the β-sheet secondary structure of amyloid peptides would be disrupted under small static EF and accompanied by transforming fibril aggregates into amorphous particles in vitro. Molecular dynamics simulations further demonstrate that even with the transformation of the secondary structure from β-sheet to random coil, the strong interaction between Aβ and hIAPP peptides would remain largely unaffected under the small static EF, leading to the formation of amorphous nanoparticles observed in the experiments. This inhibitory effect of EF on the co-fibrillation of multiple amyloid peptides might contribute to reducing the mutual deterioration of different degenerative diseases and show great potential for the noninvasive treatment of amyloid-related diseases.