Studies on polypeptides. XXIX. Synthesis of the N-terminal tetradecapeptide sequence of ribonuclease A, incorporating beta-(3-pyridyl)-L-alanine at position 12.

A description is given of the synthesis by fragment condensation of 12-(3-Pyd) Ala S-peptide (1--14), the 1--14 peptide sequence of ribonuclease A in which the histidine-12 residue is replaced by beta-(3-pyridyl)-L-alanine. The peptide binds strongly and stoichiometrically to S-protein; the resulting complex is enzymatically inactive.