Published as part of the Cluster Recent Advances in Protein and Peptide Synthesis
Abstract
Cyclic peptides are attracting attention of medicinal chemists due to their increased
stability in biological milieu as well as improved target binding affinities. Our
laboratory has recently reported a powerful cyclization strategy that takes advantage
of the spontaneous and reversible conjugation of lysine and a designed amino acid
AB3 to give iminoboronates. Herein we report that Dap, a short chain homologue of
lysine, displays significantly higher propensity to form iminoboronates and consequently
improves the efficiency of peptide cyclization. Importantly, the preferential conjugation
of AB3 to Dap allows a facile synthesis of cyclic peptides with free lysine residues.
Key words
peptide cyclization - reversible - iminoboronate - 2-APBA - Dap - pH
