The main objective of this project will be to evaluate the proteomic profile of the acquired pellicle after rinsing solutions with peptides of statherin. This incorporation may favor the ability of the acquired enamel pellicle (AEP) to protect against erosion. In preliminary experiments of our group, statherin was recently identified as a resistant protein against removal for HCl, at both pH 1 and pH 2, even in short-term formed PAE. In addition, statherin is reduced by 35% in SAP in patients with dental erosion. This is a protein of 43 amino acid residues. It is a primary sequence protein similar to osteopontin and casein, with calcium binding capability. Its negative charge density and helical conformation in the N-terminal region are important for interaction with hydroxyapatite (Raj et al., 1992), which has been confirmed in experiments involving solid state nuclear magnetic resonance (Naganagowda et al., 1998). In addition, an in vitro study reported that at least 15 N-terminal residues (StN15) or more in staterin-derived peptides are required to reduce enamel demineralization (Shah et al., 2011). Thus, it would be interesting to know how this peptide will be incorporated into the acquired pellicle, and if the presence of this additive, will significantly alter its proteomic profile, especially in a short-term film formation, since in previous studies the statherin were a precursor protein, even in short term pellicle formation. The present study, the collections will be performed in 4 consecutive days (for each type of treatment). Each day, the volunteers (n = 9) will undergo dental prophylaxis with pumice, after prophylaxis, a mouthwash with 10 ml of phosphate buffer solution with the peptide StN15 (concentration of 1.88x10-5 M determined) will be performed. in previously unpublished studies by our research group, whose in vitro study found that this concentration was most effective in protecting against initial erosion by hydrochloric acid) or with StN15 Peptide-free phosphate buffer (DpSpSEEKFLRRIGRFG). The acquired pellicle will be formed naturally on the enamel over a period of 3 minutes. Next, the film will be removed with a 3% citric acid moistened filter paper.After protein extraction, they will be subjected to reverse phase liquid chromatography linked to a mass spectrometer (nLC-ESI-MS / MS). Marker free proteomic quantification will be done using the software (PLGS).
News published in Agência FAPESP Newsletter about the scholarship: