Formation of nanostructure by self-assembly of an elastin peptide

Elastin and elastin-related peptides have great potential in the biomaterial field, because of their peculiar mechanical properties and spontaneous self-assembling behavior. Depending on their sequences and under appropriate experimental conditions, they are able to self-assemble in different fiber morphologies, including amyloid-like fibers. Temperature-triggered self-assembly of a small elastin peptide shows a novel complex aggregation mechanism as revealed by different microscopy techniques. The conformations of the peptide have been investigated in solution and in the aggregated state by different spectroscopic techniques (CD, NMR, FT-IR) and revealed that the conformations adopted by the peptides in water in the prefibrillar state correspond to those populated by other elastin peptides, mainly polyproline II helix (PPII) and random coil. Conversely, the aggregated state shows evidence for antiparallel cross-β structures. Our molecular studies highlight the important role of PPII conformation on the prefibrillar state, putting forward the hypothesis that aggregation takes place through addition of the monomer in the PPII conformation with preformed β-sheet aggregates and/or through direct interaction of PPII helices.