The Dynamics of Low and High Aspect Ratio Protein Building Blocks in Hierarchical Protein Assemblies

Hierarchical assemblies of protein are ubiquitous in living systems including collagen fibres in bone, and actin filaments in cell cytoskeletons. Our aim is to understand the underlying design principles of hierarchical protein networks, utilising folded protein-based hydrogels, a newly emerged biomaterial consisting of crosslinked folded proteins, as a controllable model system. To achieve this aim, we use a cross-length scale approach including: bulk rheology, small-angle scattering, and computational modelling. Through this approach we have gained insight into the translation of nanoscale protein thermodynamic stability to bulk network architecture and mechanics. However, this approach has not been able to probe how the protein dynamics translates to network properties. We propose to use polarised QENS as a method to directly probe the dynamics of both the protein domains within networks and the solvent confined by protein network. Furthermore, by utilising low and high aspect ratio protein constructs we will investigate how known network structure alterations affect the protein and confined solvent dynamics. This proposal will allow us to gain an insight into how the nanoscale dynamics translates to bulk properties and simultaneously how bulk properties affect the nanoscale dynamics. Such a cross-length understanding of dynamics will reveal novel biomaterial engineering routes for specific applications such as controlled drug release or responsive cell scaffolds.