Synthesis of analogs of the N-terminal eicosapeptide sequence of ribonuclease A. Part XVI. Synthesis and guanidination of (Orn10, Leu11)-and (Orn10, Lys11)-S-peptide.

For a better understanding of the role played by glut amine 11 either in the catalytic function of ribonuclease A or in the S-peptide/S-protein association process the following S-peptide analogs have been synthesized: [Orn10,Leu11]- and [Orn10, Lys11]- S peptide. The S-protein activating ability of the two synthetic S-peptide analogs was tested, before and after guanidination, by exploring their capacity to generate ribonuclease activity, against RNA as substrate, when recombined with S-protein.