Beta sheet forming peptides functionalization with biologically active motifs may alter their self-assembling propensity

Synthetic polymers and bioinspired fibrous materials have a significant impact in medicine in the recent years. The design and fabrication of new bio-materials has a great influence in several scientific and medical communities. The potential benefits to basic science include: understanding of biomolecular self-assembly in water; predicting natural biomolecular assembly from sequence information alone and at least increasing confidence to designing new natural and biomaterials. The "designing rules" of self-assembly are becoming available but not yet completely understood. RADA 16-1 undergoes molecular self-assembly into double layered β-sheet structures that spontaneously form nanofibers upon exposure to solutions at neutral pH [1]. RADA16-I functionalization with biological active motifs may influence the self-assembling tendency of new functionalized peptides. This explorative study attempts to give different tools to characterize this group of synthetic peptides. Three different functionalized peptides, showing different hydrophobicity profile and local charge, have been analyzed by micro-Raman spectroscopy and Atomic Force Microscopy (AFM). Farther more computational experiments using molecular dynamic (MD) simulations confirm the experimental findings and indicate themselves as good tools to predict the behaviour of these peptides in aqueous solution.