Developmental Changes in the PH of Enamel Fluid and Its Effects On Matrix-Resident Proteinases

The objectives of this study were to measure pH in developing enamel at progressively older (more mature) stages of amelogenesis in vivo, and then to formulate synthetic enamel fluid mixtures that approximated these pH values for in vitro studies. The ultimate goal was to characterize the molecular weights of proteinases visualized by enzymograms incubated in synthetic enamel fluid using gelatin and casein as substrates. For most experiments. the proteinases were extracted en masse from small freeze-dried enamel strips directly into a non-reducing sample preparation buffer. In some experiments, we pre-treated the enamel strips with acetic acid to determine if this common method for demineralization and protein extraction caused any changes in the activity levels of the enamel proteinases. In other experiments, we first soaked enamel strips in synthetic enamel fluid to determine solubility of the proteinases within an aqueous phase. The results indicated that the pH of developing enamel remained fairly con...