Hydroxyapatite Growth On Amelogenin-Amelotin Recombinamers

Strategies to improve hydroxyapatite mineralization for enamel repair are essential for tissue regeneration. Amelogenin and amelotin (AMTN) are enamel matrix proteins playing critical roles in enamel formation. Amelogenin acts as a scaffold for hydroxyapatite, while AMTN (specifically its 'SSEEL' domain) is necessary for proper enamel mineralization. The functional relationship between recombinant AMTN and amelogenin, and their combined ability to guide uniaxial hydroxyapatite growth in vitro has been investigated recently. However, incorporation of the active domain of AMTN within recombinant amelogenins has not been studied yet. Here we describe the synthesis of modified amelogenin by inserting, internally and at its C-terminus, the mineralizing AMTN-derived motif SSEEL. C-terminus modified amelogenin promoted hydroxyapatite formation, whereas internal incorporation of the motif initially resulted in amorphous calcium phosphate formation. Here we show that modified amelogenin with the mineralizing AMTN-motif SSEEL can promote hydroxyapatite growth. These results give new insights for mineralized tissue regeneration using recombinamer proteins.