Tunable 1D supramolecular architectures constructed via solution and chemical assembly of model coiled coil peptides

Coiled coils present a diverse toolbox for constructing robust biomaterials. Computational design of coiled coil forming peptides further enables their use as designer ‘molecular Legos’ to construct new materials with tunable nanostructure. We employ computationally designed coiled coil peptides that form stable antiparallel homotetramers to build novel supramolecular architectures. Specifically, by end-functionalizing peptides with complimentary ‘click’ reactive groups, coiled coils were covalently linked to form 1D chains of desired length and flexibility: a short linker between them yielded rigid rods while a long linker yielded flexible fibers. Small angle neutron scattering was used to characterize their nanostructure under different solution conditions. Polarized optical microscopy of concentrated 100 nm long rigid rods showed formation of liquid crystal phases. Interestingly, the phase behavior depended on salt concentration, rod length and the design of peptides used to construct them. This has given us valuable insight into the physics of their macroscopic assembly and is further informing future designs of more complex coiled-coil based nanomaterials.