  Above a critical concentration a wide variety of peptides and proteins
self-assemble into amyloid fibrils which entangle to form percolating networks
called hydrogels. Such hydrogels have important applications as biomaterials
and in nanotechnology, but their applicability often depends on their
mechanical properties for which we currently have no predictive capability.
Here we use a peptide model to simulate the formation of amyloid fibril
networks, and couple these to elastic network theory to determine their
mechanical properties. The simulations reveal that the time-dependence of
morphological quantities characterizing the network length scales can be
collapsed onto master curves by using a time scaling function that depends on
the interaction parameter between the peptides. The same scaling function is
used to unveil a universal, non-monotonic dependence of the shear modulus with
time. The obtained insight into the structure-function relationship between the
peptide building blocks, network morphology and network mechanical properties
can aid experimentalists to design amyloid fibril networks with tailored
mechanical properties.
