Amelogenin Nanospheres Supra-Molecular Assembly and the Preferential Orientation of Apatite Crystals

Dental enamel is a bio-ceramic formed through a cascade of intra and extra-cellular events among which protein self-assembly is a critical step. Amelogenin selfassembly into nanospheres has been proposed as a key factor in controlling the oriented and elongated growth of enamel crystals. This manuscript is a short review of our recent in vitro study on the process of amelogenin selfassembly into higher order structures. We report characterization of birefringent micro-ribbons formed by the supramolecular assembly of amelogenin nanospheres (10-25nm) through nano-chains of >100nm in length. Mineralization of the micro-ribbons resulted in the formation of remarkably ordered apatite crystals oriented with their c-axes parallel to the long ribbon axes. The strong tendency of amelogenin to form nanospheres which self-assemble into linear structures provides a new insight into the function of amelogenin as a template for the oriented growth of crystals during enamel biomineraization.