RAD16II β-Sheet Filaments onto Titanium Dioxide:  Dynamics and Adsorption Properties

The adsorption and dynamics of a β-sheet filament made of RAD16II self-assembled peptides onto the TiO₂ rutile (110) surface in aqueous solution have been studied through classical molecular dynamics simulations. Different arrangements of the filament on the surface have been considered and analyzed in order to identify preferential binding modes. The simulations results suggest that RAD16II filaments can strongly adsorb onto titanium dioxide surfaces through direct and indirect interactions of their charged side chains with both titanium and oxygen atoms of the these interfaces, in agreement with experimental data. The strength of adsorption, which is strictly connected with the number and type of peptide−surface contacts, governs the filament mobility. However, side chain interactions have little influence on the flexibility of the supramolecular aggregate. Indeed, the integrity of the filament is maintained by backbone hydrogen-bonding interactions, which are preserved during the whole simulation time.