Self-assembling Protein Materials for Metal Nanoparticle Templation

• Main Author: Hume, Jasmin
• Format: Dissertation
• Language: English
• Subjects: biochemistry; chemistry; materials science
• ISBN: 1321892896; 9781321892895

The fabrication of de novo proteins able to self-assemble on the nano- to meso- length scales is critical in the development of protein-based biomaterials in nanotechnology and medicine. Proteins that template and stabilize nanoparticles can serve as agents in biodetection and imaging, as well as serving in applications in catalysis and biosensing. Here we report the design and characterization of protein-engineered coiled-coils that not only assemble into microfibers but also can bind hydrophobic small molecules and template inorganic nanoparticles. Under ambient conditions proteins form fibers with nanoscale structure possessing large aspect ratios formed by bundles of alpha-helical homopentameric assemblies, which further assemble into mesoscale fibers in the presence of curcumin through aggregation. The same protein materials have been used to template gold nanoparticles (AuNPs) and iron oxide nanoparticles (MNPs) in situ, leading to very distinct assemblies and properties that are largely dependent upon the protein secondary structure. Genetic engineering, as well as protein engineering techniques such as enzymatic site-specific cleavage, unnatural amino acid incorporation, and covalent binding of orthogonal peptides have been employed in this work to fully manipulate and control physical properties of self-assembling protein materials and direct the templation of metal nanoparticles thereupon.