Peptidocalixarenes in molecular recognition

Calix[4] arenes have been extensively studied for their ability to act as synthetic receptors for metal ions and small molecules and, more recently, for use as enzyme mimics and molecular capsules. While the literature on substituted calixarenes is extensive, calixarenes that are substituted with amino acids and peptides-i.e., peptidocalixarenes-have received relatively little attention. The use of peptidocalixarenes as hosts is attractive because of the chirality and range of functional groups provided by amino acids. Calixarenes containing amino acids at the upper rim, at the lower rim or incorporated into the macrocycle have been prepared and many of these molecules have been investigated for their molecular recognition properties. Peptidocalixarenes have been demonstrated to bind small, organic molecules and metals, with high selectivity in some cases. In particular, stereoselectivity has been observed for the interaction of peptidocalixarenes with chiral molecules. Peptidocalixarenes that bind to proteins and disrupt protein-protein interactions have also been reported. This review describes the work that has been reported to date on the synthesis and properties of peptidocalixarenes. These recent and exciting results in calixarene chemistry lay the foundation for future developments in the application of peptidocalixarenes to significant research problems in molecular recognition chemistry.