Silk-inspired low-molecular-weight organogelator.

A minimal sequence from natural silks, the tetrapeptide GAGA, has been used as inspiration for the design of a new organogelator. Gels were obtained in several organic solvents, and their microscopic aspects were studied by transmission and cryo-scanning electron microscopies (TEM and cryo-SEM). FT-IR spectroscopy, circular dichroism, and wide-angle X-ray diffraction were used to study the self-assembly features of this molecule, and evidence of an antiparallel beta-sheet organization was obtained. Remarkably, the precise secondary structure uniqueness found in Nature was successfully transferred into a small synthetic analogue that self-assembles driven only by noncovalent interactions.