Self-Assembled Protein-Based Biomaterials with Tailorable Physical Properties

Soft biomaterials are used in a variety of applications such as scaffolds for cell growth and coatings for implants or transplants. We aim to create a protein hydrogel that will self-assemble upon the mixing of two different protein constructs. This is accomplished using Streptavidin, a protein that tetramerizes, and SpyTag-SpyCatcher, a protein-peptide that spontaneously forms covalent bonds, as the crosslinking mechanisms. Further, using protein building blocks whose viscoelastic properties are known from single-molecule force spectroscopy (SMFS), we aim to create a hydrogel whose physical properties are tailorable by altering the building blocks incorporated in the constructs. This thesis focuses on using an atomic force microscope for force spectroscopy and imaging to analyze the formation of networks upon mixing various protein constructs. We find that small scale networks form using both Streptavidin and SpyTag-SpyCatcher as crosslinkers and that SpyCatcher can be used to detect molecular crosslinking and polyprotein polarization through SMFS.