Mechanics of amelogenin TRAP protein in the proximity of hydroxyapatite mineral is altered by interfacial water

Abstract

Enamel is a composite bioceramic that covers teeth. Here, based on molecular dynamic (MD) simulation, we seek a better understanding of the interactions between the enamel matrix proteins with hydroxyapatite (HAP) crystal surfaces. These interactions occur during enamel formation and are responsible for controlling the formation of high aspect ratio carbonated hydroxyapatite nanocrystallites, whereas, in mature enamel, they are implicated to alter the mechanical properties of mature enamel to yield a tough composite that resists fracture during chewing. We choose an archetypal matrix protein known as tyrosine-rich amelogenin peptide (TRAP), which is retained among the HAP crystallites of mature enamel. Our findings provide molecular details to the emerging blueprint needed to engineer a biologically inspired enamel restorative material.