Biomimetic self-assembly of tetrapeptides into fibrillar networks and organogels

The self-assembly features of a family of tetrapeptides with a silk-inspired structure are presented. An exhaustive study of the influence of the terminal alkyl chain length in this process is undertaken. Scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD), FTIR spectroscopy, and circular dichroism were used for structural analysis. These compounds, as in the natural model, self-assemble into antiparallel beta-sheet structures that further organize to form fibrillar aggregates. Furthermore, some of them are capable of forming a crowded network that entraps the solvent leading to physical gels with different microscopic morphologies. A model for the assembly process is proposed. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).