Proteome of Human Acquired Enamel Pellicle on Deciduous Teeth

Understanding the composition and structure of the Acquired Enamel Pellicle (AEP) has been a major goal in oral biology. Our lab has conducted studies using mass spectrometry and proteomics on the composition of AEP formed on permanent enamel. Our exhaustive exploration has provided a comprehensive identification of more than 100 proteins from AEP formed on permanent enamel. AEP formed on deciduous enamel has not been subjected to the same biochemical characterization scrutiny as those of permanent enamel, despite the fact that deciduous enamel is structurally different than permanent enamel. We hypothesized that the AEP proteome formed on deciduous enamel may also be composed of unique proteins, some of which may not be common to AEP proteome of permanent enamel.Objective: The aim of this project is to investigate the proteome of human acquired enamel pellicle on deciduous teeth. Method: Deciduous human teeth were incubated with 300ug of saliva at 22°C for 2 h. After the pellicle-formation period, tooth specimens were removed and rinsed under distilled water for 10 seconds to remove residual saliva. The in vitro AEP material formed on deciduous enamel was harvested with 3% citric acid and sonication for 5 minutes. AEP proteins were trypisinized and subjected to mass spectrometry analysis. Result: At least 132 proteins were found based on the identification of two or more different peptides from the same parent protein. The theoretical pI of these AEP proteins fell mostly with the acidic range indicating that they exhibit negative charges at neutral pH.Conclusion: This is the first study to provide a comprehensive investigation of AEP on deciduous enamel. The MS approaches used open new avenues for the characterization of AEP components facilitating structural and functional in vivo studies.