Controlling the formation of peptide films: fully developed helical peptides are required to obtain a homogeneous coating over a large area

The influence of conformational dynamics on the self-assembly process of a novel, conformationally constrained, analogue of the natural, antimicrobial peptide trichogin GA IV was analysed by spectroscopic methods, microscopy imaging at nanometric resolution, and molecular dynamics simulations. The formation of peptide films at the air/water interface and their deposition on a graphite or a mica substrate were investigated. Combining experimental evidence with molecular dynamics simulation, we demonstrate that only the fully-developed helical structure of the analogue promotes formation of ordered aggregates nucleating the growth of micrometric rods, that give rise to homogeneous coating over wide regions of the hydrophilic mica. This work proves the influence of helix flexibility on peptide self-organization and orientation on surfaces, key steps in the design of bio-inspired organic/inorganic hybrid materials.