Amelogenin Degradation by an Enzyme Having Acidic pH Optimum and the Presence of Acidic Zones in Developing Bovine Enamel

Abstract

Protein content in immature enamel decreases dramatically during development. Disappearance of high-molecular weight proteins and relative increase in low molecular weight fractions are observed at the later stage of the development. This fact suggests degradation of matrix components during the process of enamel development and maturation. We purified and characterized an enzyme responsible for amelogenin degradation in developing enamel. Interestingly, the optimum pH of the enzyme was found to be in acidic pH, approximately at 6. This result suggested importance of acidic conditions in degradation process of the amelogenin matrix during enamel maturation. The authors attempted to stain developing teeth with pH indicators and found the presence of alternating acidic and neutral zones in developing enamel.