A chemically-controlled supramolecular protein polymer formed by a myoglobin-based self-assembly system

Artificial self-assembling systems comprised of proteins have the potential not only for mimicking naturally occurring protein clusters but also for creating functionalized supramolecular polymers. Here we report a new type of a supramolecular protein polymer which utilizes the original character and reactivity of the monomer protein. Myoglobin, an oxygen storage hemoprotein, was chosen as the monomer unit and was provided with an externally-attached heme on the protein surface which drives the formation of the fibrous supramolecular assembly through successive interprotein interactions between the external heme and the protein matrix. This assembly governed by myoglobin characteristics shows chemically-responsive stability and can be converted into extremely large protein clusters via cross-linking. Interestingly, the assembly retains the oxygen storage function. Our present system can be used for construction of smart nanobiomaterials using various hemoproteins.