[A study of parotid salivary proteins from caries-free and caries-active people by high performance liquid chromatography].

In this study, we isolated and analysed parotid salivary proteins of different individuals with different caries-susceptibility. Protein fractions isolated were identified by biochemical methods. The results showed that six proteins were isolated from parotid saliva by HIC (hydrophobic interaction chromatography). Four proteins were found in all hydrophobic interaction chromatography. Three of them were identified as different polymorphic forms of proline-rich proteins (PRPS) and the other as alpha-amylase. Comparing chromatography of fifteen healthy caries-free adults with ten caries-active adults, we found that there was no difference in salivary protein composition. Three different phenotypes of PRPS had different relations with caries-susceptibility and relative ratios of the three PRPS were different between two groups. It suggested that abnormal proportions of salivary proteins may be another important determinant in caries-susceptibility.