Helical-ribbon formation by a beta-amino acid modified amyloid beta-peptide fragment.

An addition to the family: The introduction of beta-amino acid residues into a modified amyloid beta peptide fragment resulted in well-defined helical nanoribbons (see cryo-TEM image) comprising beta strands mainly oriented perpendicular to the ribbon axis. The nanoribbons order into a flow-aligning nematic phase at higher concentration. The beta-strand nanoribbon structure is an addition to the known set of secondary structures adopted by beta-peptides.