Amino acid sequences of glycopeptides obtained from basic proline-rich glycoprotein of human parotid saliva.

A proline-rich glycoprotein, in which proline, glutamic acid, and glycine represent about 80 per cent of the total residues, was obtained from human parotid saliva. The amino acid sequences of glycopeptides obtained from digests of the glycoprotein with clostripain were determined to be Pro-Gly-Lys-Pro-Glu-Gly-Pro-Pro-Pro-Gln-Gly-Gly-Asn(CHO)-Gln-Ser-Gln-Gly-Pro- Pro-Pro-Arg and Pro-Pro-Gln-Gly-Gly-Asn(CHO)-Gln-Ser-Gln-Gly-Pro-Pro-Pro-His-Pro-Gly-Lys-Pro -Glu-Arg. The structural relationship between the glycopeptides and the known salivary peptide is discussed.