Self-Assembly of Binary Peptide System in the Solid State Induced by the Presence of Environmental Water -An Unusual Case of Ex-Vivo Peptides Cooperation

Abstract

During the solid-state self-assembly of the binary peptide system, the preferred crystallographic forms are selectively altered relative to the individual components, indicating mutual influence between the peptides. Even when both peptides occupy separate domains but remain in close contact, they exhibit cooperative behaviour. Such cooperation, mediated by water transfer between phases, leads to highly ordered hydrated crystals with distinct morphologies. This phenomenon is demonstrated using a physical mixture of the Pro–Val–Pro–Val and Val–Pro–Val–Pro tetrapep tides. Detailed analysis of high-resolution solid-state NMR and single-crystal X-ray diffraction data provides evidence for these unexpected structure–property relationships.