Endowing a ferritin-like cage protein with high affinity and selectivity for certain inorganic materials

The assembly of inorganic matter directed protein cages from the engineered L chains of hose ferritin was studied. Ferritin is a cage-shaped protein with a nanometer-sized interior space in which a variety of inorganic nanoparticles including oxidized Fe,[2] oxidized Co,[3] can be mineralized. The reconstituted ferritin like cage proteins retained the capacity to mineralize iron and showed the ability of the parental aptamers for selective binding against certain inorganic materials. The L chain also tolerated addition of NHBP-1, a 12 amino acid aptamer of carbon nanomaterial, at its N terminal, and reconstituted a cage protein that retained the ability both to mineralize Fe and bind to the surface of SWNH aggregates. The interior space of cage proteins can serve as a reservoir for a variety of inorganic materials and could be used to assemble a wide variety of novel inorganic composite materials on the nanoscale.