First crystallographic signature of the highly ordered supramolecular helical assemblage from a tripeptide containing a non-coded amino acid

The model tripeptide Boc-Leu(1)-Aib(2)-Phe(3)-OMe 1 containing a non-coded amino acid residue (Aib: α-amino isobutyric acid) forms a supramolecular helical assemblage via non-covalent interactions in single crystals. The SEM image of the peptide 1 in the solid state shows the ribbon like fibrillar morphology, a characteristic feature of highly ordered aggregated fibrils like amyloid fibrils.