Cation Binding by the Rat‐Incisor‐Dentine Phosphoprotein

Nuclear magnetic resonance and electron paramagnetic resonance spectroscopy have been used to quantify metal binding to the phosphoprotein extractable from demineralized rat incisor dentine. Paramagnetic cation probes enable identification of the metal binding sites. Cations are able to diffuse across the protein surface while forming a relatively long-lived metal-phosphoprotein complex. The ability of the protein to sequester surface-mobile Ca(II) is discussed in terms of its ability to act as a possible nucleation site for the initial localization of Ca(II) within the dentine matrix.