Atomistic picture of the self-assembly dynamics of phenylalanine tripeptide into nanofibres: hierarchical mechanism and the role of on-pathway water dynamics

Dynamics of assembly processes is a poorly understood area of the broad field of spontaneous molecular self-assembly. In this paper, we present an all-atom molecular dynamics simulation study on the mechanism of spontaneous self-assembly of an aqueous mixture of uncapped phenylalanine tripeptides into nanofibres. The mechanism was found to be hierarchical in nature and complex combinations of intermolecular interactions played out over multiple timescales. The final outcome of the assembly could not be explained solely on the basis of solute-solute interactions, suggesting an active role of the solvent. The on-pathway slow dynamics of interfacial water molecules attached to the transient molecular clusters appeared to play a crucial role in the possible kinetic control that leads to nanofibres as the dominant end-product of the assembly.