In recent years, metal-organic frameworks (MOFs) have received much attention for a variety of applications due, in part, to their highly customizable supramolecular architecture. Typically, MOFs are composed of metal-coordinating organic ligands (struts) and metal ions/clusters (nodes). Following the construction principles of MOFs, we have rationally designed the first example of a ternary protein-based metal-organic framework. Surface exposed metal binding sites were engineered at the C<sub>3</sub> symmetric pores of ferritin, an octahedral iron storage protein. These designed metal coordination sites exhibit a nearly perfect tetrahedral geometry after binding zinc. The outward facing open coordination site on each zinc ion is poised for the binding of an organic ligand. In the presence of certain ditopic metal-binding ligands, the zinc-bound ferritin nodes self-assemble into an ordered crystalline framework held together by the organic struts. The symmetry of these protein-based MOFs is dictated both by the metal coordination sites on the surface of ferritin and the symmetry of the organic bridging ligands. This work highlights an exciting new direction for the rational design of protein-based supramolecular crystalline frameworks.

Protein-based metal-organic frameworks

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.