Experimental Insights into Conformational Ensembles of Assembled β-Sheet Peptides

Abstract

Deciphering the conformations and interactions of peptides in their assemblies offers a basis for guiding the rational design of peptide-assembled materials. Here we report the use of scanning tunneling microscopy (STM), a single-molecule imaging method with a submolecular resolution, to distinguish 18 types of coexisting conformational substates of the β-strand of the 8-37 segment of human islet amyloid polypeptide (hIAPP 8-37). We analyzed the pairwise peptide− peptide interactions in the hIAPP 8-37 assembly and found 82 interconformation interactions within a free energy difference of 3.40 k B T. Besides hIAPP 8-37, this STM method validates the existence of multiple conformations of other β-sheet peptide assemblies, including mutated hIAPP 8-37 and amyloid-β 42. Overall, the results reported in this work provide single-molecule experimental insights into the conformational ensemble and interpeptide interactions in the β-sheet peptide assembly.

Silk Fibroin-Based Triboelectric Nanogenerators for Energy Harvesting and Biomedical Applications

“…SF is renowned for its exceptional mechanical properties stemming from its intricate hierarchical structure. At the nanoscale, SF molecules organize into β-sheet microcrystals embedded within an amorphous matrix, imparting outstanding tensile strength and flexibility. , This layered arrangement enables SF to withstand mechanical stress and deformation, making it an ideal choice for constructing robust TENGs. Additionally, the toughness of SF ensures the longevity and reliability of TENG devices even under dynamic operating conditions .…”