Iminoboronate-Mediated Peptide Cyclization with Lysine HomologuesThe financial support of this project is provided by the National Institutes of Health via grant GM102735
Received: 13 April 2017
Accepted after revision: 28 May 2017
05 July 2017 (eFirst)
Published as part of the Cluster Recent Advances in Protein and Peptide Synthesis
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.