Conformational study of the salivary proline-rich polypeptides.

The conformational study of three proline-rich polypeptides of human whole saliva, with known primary structures, was performed by CD and 1H-n.m.r. spectra measurements. All these polypeptides contained more than four consecutive prolyl residues in their amino acid sequences. The occurrence of the poly-L-proline form II conformation in their structures was demonstrated with two of these polypeptides. The continuous prolyl residues in the third was suggested to take the same structure as the others.