Toroidal nanostructures from self-assembly of block copolypeptides based on poly(L -arginine) and β-sheet peptide

We demonstrate here that rationally designed block copolypeptides based on poly(L-arginine) and β-sheet peptides can form toroidal nanostructures. In aqueous solution, we found that 1D nanoribbons roll up and connect in an end-to-end fashion under charge-balanced conditions, resulting in the formation of barrel-like toroidal nanostructures. Toroidal diameter was highly uniform (10 nm), indicating that there is a preferred geometrical packing requirement for toroid formation. Our results demonstrate that, when suitably designed, β-sheet nanostructures can be manipulated to form more complex 2D nanostructures. This finding offers new opportunities not only for the fabrication of more sophisticated peptide-based nanobiomaterials, but also for understanding and inhibiting protein misfolding diseases. Block copolypeptides based on poly(L-arginine) and β-sheet peptide, can form toroidal nanostructures in aqueous solution by rolling-up of 1D nanoribbon and end-to-end connection of the nanoribbon under charge balanced condition. This finding offer new opportunity not only for fabricating more sophisticated peptide-based nanobiomaterials, but for understanding protein misfolding mechanism also.