Fig. 2. The influences of peptide configurations in the presence of dhAA residues and common synthetic methods to generate Dha/Dhb residues in peptide chemistry. (A) The normal 3.010-helix in proteins (top) and the unusual 2.05-helix when peptidyl foldamers contain contiguous Dha residues (bottom). (B) The conformational changes of Z- and E-isomers when ΔβAla-containing peptides are treated with UV irradiation. (C) A common synthetic method in peptide chemistry to provide a Dha/Z-Dhb residue via an overall anti-elimination pathway. (D) A common synthetic method in peptide chemistry to provide an E-Dhb residue via an overall syn-elimination pathway.
