Control of peptide secondary structure on star shape polypeptides tethered to polyhedral oligomeric silsesquioxane nanoparticle through click chemistry

New macromolecular self-assembling building blocks, star polypeptide-b-polyhedral oligomeric silsesquioxane (POSS) copolymers, were synthesized from octa-azido functionalized POSS (OVBN3-POSS) with alkyne-poly(γ-benzyl-l-glutamate) (alkyne-PBLG) via a click reaction. The incorporation of POSS units at the core of PBLG moieties plays an important role, allowing intramolecular hydrogen bonding between the POSS and PBLG units to enhance the α-helical conformations in the solid state based on Fourier Transform Infrared spectroscopy (FTIR), solid state nuclear magnetic resonance (NMR), and wide-angle X-ray diffraction (WAXD) analyses.