(186c) Properties of Self-Assembled Peptide Fibers

Micron-sized peptide fibers can be formed from the multi-scale assembly of combinations of peptides.  The peptides required are a short, hydrophobic “template” and a longer, alpha-helix “adder”.  Nanometer-sized cross-beta fibrils assemble and then helically wind around each other to build the large fiber.  The helical pitch is determined by the inter-fibril interaction energy and defines the modulus of the fiber.  Modulus can then be controlled by choice of peptides and relative concentration.  The fibers resemble silk and keratin in morphology and modulus can vary from a fraction of a GPa to several GPa.  The peptide systems described are obtained from economical, abundant plant sources and show a unique way to easily build high performance biomaterials that rival more expensive, harder to obtain materials.