Role of single disulfide linkages in the folding and activity of scyllatoxin-based BH3 domain mimetics.

Anti-apoptotic Bcl-2 proteins are implicated in pathogenic cell survival and have attracted considerable interest as therapeutic targets. We recently developed a class of synthetic peptide based on scyllatoxin (ScTx) designed to mimic the helical BH3 interaction domain of the pro-apoptotic Bcl-2 protein Bax. In this communication, the contribution of single disulfides in the folding and function of ScTx-Bax peptides was investigated. We synthesized five ScTx-Bax variants, each presenting a different combination of native disulfide linkage and evaluated their ability to directly bind Bcl-2 in vitro. It was determined that the position of the disulfide linkage had significant implications on the structure and function of ScTx-Bax peptides. This study underscores the importance of structural dynamics in BH3:Bcl-2 interactions and further validates ScTx-based ligands as potential modulators of anti-apoptotic Bcl-2 function. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.