Atomistic insights into the structure of heptapeptide nanofibers

Artificial amyloid-like nanofibers formed from short peptides are emerging as new supramolecular structures for catalysis and advanced materials. In this work, we analyze, by means of computational approaches, the preferred atomistic fibrillar architectures that result from the self-assembly of polar NY7, NF7, SY7, SF7, and GY7 peptides into steric zippers formed by two beta-sheets (describing an individual steric zipper) and by four beta-sheets. For all heptapeptides, except GY7, parallel beta-sheet organizations with polar residues packed at the steric zipper appear to be the preferred assemblies for the two beta-sheets system due to the formation of a strong network of hydrogen bonds. For GY7, however, an antiparallel organization with glycine at the steric zipper is the most stable one. The preferred architecture is mostly conserved when enlarging our model from two to four beta-sheets. The present work shows that the relative stability of different architectures results from a delicate balance between peptide composition, side chain hydrophobicity, and non-covalent interactions at the interface and provides the basis for a rational design of new improved artificial prion-inspired materials.

Automated summary

This study analyzes the preferred atomistic fibrillar structures formed from short peptides self-assembled into artificial amyloid-like nanofibers. It identifies parallel beta-sheet organizations with polar residues as the preferred assembly due to the formation of strong hydrogen bond networks. The research provides a basis for the rational design of new improved artificial prion-inspired materials.