Helical intermediate formation and its role in amyloids of an amphibian antimicrobial peptide
Anup Kumar Prasad, Lisandra L. Martin, Ajay S. Panwar
Abstract
-helices transitioned into α-helices, thereby imparting partial helical conformations to the peptides. In the initial stages of aggregation, U3.5 peptides with amphipathic, partial helices were driven closer by hydrophobic interactions to form small clusters of helical intermediates. These helices imparted stability to the helical intermediates, which promoted the growth of clusters by further addition of peptides. This led to an increase in the local peptide concentration, which enabled stronger peptide-peptide interactions and triggered a β-sheet transition in these aggregates. Thus, this study emphasized that the helical intermediates may be crucial to the evolution of β-sheet-rich amyloid structures.