Protein engineering of a viral cage for constrained nanomaterials synthesis

Cage architectures based on the cowpea chlorotic mottle virus were used to achieve a synthetic mimic of the iron storage protein ferritin. The electrostatic nature of the inner protein surface could be changed by up to 3240 units of charge, while still maintaining a stable cage structure. The spatial isolation within the protein cage prevented bulk aggregation of the mineral particles and resulted in a stable, mono-disperse colloid.