The association of basic proline-rich peptides in human parotid gland secretions with caries experience.

摘要

We have examined the relationship between low molecular weight salivary peptides and dental cavity (caries) experience. Samples of parotid saliva were collected from 9 caries-free (CF) and 9 caries-susceptible (CS) mature individuals (>50 yr.). Ethanol soluble materials were fractionated on columns of BioGel P-2 and further examined by cation exchange HPLC. Each sample was resolved into nineteen peptides that are most likely the proteolytic cleavage products of the basic-proline rich proteins IB-4, IB-5, IB-7, IB-8b and PB. Quantitation of peptide levels indicated that there are five peptides more abundant in saliva obtained from CS individuals, and six peptides as well as an intact putative precursor protein IB-7 more abundant in saliva obtained from CF individuals (P 0.05). Examination of the sequences suggests that the peptides may be generated by cleavages due to Trypsin-like, as well as Prolyl- and Glutamyl-like endopeptidases.; The cysteine protease inhibitors, cystatins, may also affect the caries process by modulating the re-mineralization of tooth enamel due to their calcium binding properties. To examine their associations to caries we determined the levels of cystatin isoforms S and SN in mixed saliva using indirect ELISA. CF individuals had statistically higher levels of the two isoforms (P 0.01).; Our data suggests evidence that individuals with differing history of caries experience process basic proline-rich salivary proteins differently.