Fractionation and Characterization of Basic Proline-Rich Peptides of Human Parotid Saliva and the Amino Acid Sequence of Proline-Rich Peptide P-E

Basic proline-rich peptides of human parotid saliva were fractionated and characterized. The amino acid sequence of one of the purified peptides, P-E, was determined to be SPPGKPQGP P 10 PQGGNQPQG P 20 PPPPGKPQG P 30 PPQGGNRPQ G 40 PPPPGKPQG P 50 PPQGDKSRS P 60 R. The results demonstrate the repetitiveness of the partial sequence within the molecule and the occurrence of structures common to those of other salivary poly-peptides such as P-C and Protein C.