Abstract:

Metalloproteins comprise an estimated one third of the proteome and play crucial catalytic, electron-transfer, structural, and storage roles. The protein environment surrounding metal cofactors is instrumental to catalysis, dictating the flow of substrates, products, and electrons to and from active sites. Here, we leverage artificial metalloproteins to uncover structure-function relationships and determine which features in the protein environment are most essential in engineering function. This dissertation discusses the design of artificial blue copper proteins in streptavidin which adopt unusual coordination geometries. The local environment can be modulated to direct binding to an endogenous cysteine residue, and to engineer a distorted “red copper” site capable of imposing post-translational modifications on the protein scaffold. Additionally, we use artificial systems to explore the assembly of dinuclear iron sites and the engineering of copper systems for the oxidation of organic substrates. These studies enhance our understanding of the role confinement in a protein host in dictating the reactivity at metal centers.