Mass spectrometric analyses of peptides and proteins in human gingival crevicular fluid

Gingival crevicular fluid (GCF) is a pathophysiological fluid that flows into the oral cavity. Human GCF was collected using sterile glass microcapillary tubes from inflamed periodontal sites in patients who had a history of periodontal disease and were in the maintenance phase of treatment. Samples from individual sites were analyzed using MS techniques both before and following HPLC. GCF samples were also pooled and subjected to SDS-PAGE, in-gel digestion and MS analyses using both MALDI-TOF/TOF MS and nanoLC-ESI-MS/MS. MS spectra were used to search human protein sequence databases for protein identification. With these approaches, 33 peptides and 66 proteins were positively identified in human GCF. All of the peptides discovered in this study are reported in GCF here for the first time. Forty-three of the identified proteins, such as actin and the actin binding proteins profilin, cofilin and gelsolin, have not been reported in GCF before.