The supramolecular organization and the conformational properties of the elastin-related octapeptide ALGGGALG, and its polymer, are studied by electron microscopy and molecular dynamics simulations. Our results evidence the complex nature of the single molecule and its aggregates, both from the structural and the dynamic points of view, indicating that a low-level complex behaviour exists in the building blocks of the elastin molecule. In particular a remarkable molecular mobility is observed around a central hinge zone. This confirms the role of the phase transition fractal-to-Euclidean in the framework of the well-known entropic mechanism of elastin elasticity.