Dynamic Combinatorial Enrichment of Polyconformational D-/L-Peptide Dimers

D-/L-Peptides such as gramicidinA (gA) adopt unique dimeric beta-helical structures of different topologies. To overcome their conformational promiscuity and enrich individual components, a dynamic combinatorial approach assisted by thiol tags was developed. This method led to identification of the preferential formation of antiparallel dimers under a broad range of conditions, which was independent of peptide side-chain polarity. Exclusive formation of an antiparallel cyclic dimer was achieved in the presence of cesium ions.