Elimination of branching in beta-hairpin self-assembling peptides

Nanoscale fibril self-assembly in (VK)4VDPPT (KV)4-NH2 peptides is initiated by intramolecular peptide folding into a beta-hairpin conformation. Once folded, the peptides undergo intermolecular bilayer formation due to hydrophobic collapse of hydrocarbon valine side chains, all located on one face of respective folded beta-hairpins. Subsequent intermolecular hydrogen bonding between folded hairpins leads to fibril formation. A physically crosslinked network structure is formed due to fibrillar entanglement and defects in hydrophobic collapse that nucleate branching points. We attempt to design ``lock and key'' specificity in the hydrophobic faces of the folded beta-hairpins so that only 1-d fibril formation can occur without any branching. The success of the new peptide designs to rid the system of branching and characteristics of the networks afforded by new peptide sequences and blends thereof will be discussed by various characterization techniques such as Rheological Characterization, Circular Dichroism (CD), Transmission Electron Microscopy (TEM) and Small Angle Neutron Scattering (SANS). ~