Controlling protein assembly on mineral surface with designed interfaces

Abstract

Proteins that interface with inorganic crystals have critical functions in biology. For example, biomineralization proteins form hard tissues such as bone, abalone shell, and sponge spicules, and mineral binding proteins in iron-reducing bacteria transfer electrons to their environment. While the atomistic details of natural protein-mineral interfaces remain largely unknown, inspiration for design can be gleaned from ice-binding proteins that display arrays of amino-acid side-chains spaced in regular intervals that geometrically match the ice lattice surface. Collaborators and I hypothesized that a similar lattice-matching approach could be used to design interactions between proteins and minerals. Using designed-helical repeat proteins engineered to adsorb and assemble on the mica (001) surface, we demonstrated this approach can control protein assembly on the surface of an inorganic crystal.