Solid-Phase Synthesis of Aza-Lysine Peptide Analogue of Trypsin Substrate

Lysine residues play critical roles in biological processes, such as protein post-translational modifications, enzymatic cleavage, and cell penetration. Constrained Lys residues may thus serve as tools for studying the structural requirements for such phenomenon. Azapeptides contain semicarbazide residues that may favor turn geometry, enhance molecular recognition and prevent protease degradation [1]. We have developed general methods for inserting aza-lysine residues and various side chain derivatives anywhere within a peptide sequence (Figure 1) [2-4].