Observation of glycine zipper and unanticipated occurrence of ambidextrous helices in the crystal structure of a chiral undecapeptide

Background  

The de novo design of peptides and proteins has recently surfaced as an approach for investigating protein structure and function. This approach vitally tests our knowledge of protein folding and function, while also laying the groundwork for the fabrication of proteins with properties not precedented in nature. The success of these studies relies heavily on the ability to design relatively short peptides that can espouse stable secondary structures. To this end, substitution with α, β-dehydroamino acids, especially α, β-dehydrophenylalanine (ΔPhe) comes in use for spawning well-defined structural motifs. Introduction of ΔPhe induces β-bends in small and 3₁₀-helices in longer peptide sequences.