1986 Volume 34 Issue 9 Pages 3803-3811
An active peptide which stimulates dentinal fluid transport (DFT) through the dentinal tubules in the molar teeth of rats was isolated by aqueous extraction, isoelectric precipitation, ultrafiltration, gel filtration, cation exchange chromatography, a peptide mapping procedure and gel filtration from rat parotid glands. The minimum effective dose of the purified DFT-stimulating peptide was 1 μg per kg of body weight in the bioassay for DFT-stimulating activity, as indicated by the migration of a fluorescent dye through the dentinal tubules in the molar teeth of rats.The complete amino acid sequence of DFT-stimulating peptide was determined by dansyl-Edman degradation, manual Edman degradation, carboxypeptidase digestion and tryptic peptide analysis. The final sequence was Gl^^1y-Val-Ile-Ala-Trp-Glu-Leu-Gln-His-A^^(10)sn-Glu-Pro-Gly-Arg-Lys-Asp-Ser-Thr-Ala G^^(20)ly. The rat DFT-stimulating peptide thus consisted of a total of 20 amino acid residues and the calculated molecular weight was 2165.