Scaffolded multiple cyclic peptide libraries for protein mimics by native chemical ligation

The accessibility to collections, libraries and arrays of cyclic peptides is increasingly important since cyclic peptides may provide better mimics of the loop-like structures ubiquitously present in and - especially - on the surface of proteins. The next important step is the preparation of libraries of ensembles of scaffolded cyclic peptides, which upon screening may lead to promising protein mimics. Here we describe the synthesis of a tri-cysteine containing scaffold as well as the simultaneous native chemical ligation of three cyclic peptides thereby affording a clean library of multiple cyclic peptides on this scaffold, representing potential mimics of gp120. Members of this collection of protein mimics showed a decent inhibition of the gp120-CD4 interaction.