A research paper written by Kaori Furukawa (Graduate School of Biomedical Sciences) et al was selected as a front cover picture of Organic & Biomolecular Chemistry.

Kaori Furukawa (Supervisors: Associate Prof. Makoto Oba; Prof. Masakazu Tanaka in Institute of Biomedical Sciences) et al developed a novel methodology to change peptide secondary structures from a helical to random structure in response to the acidic conditions.
α,α-Disubstituted α-amino acids (dAAs) are promising tools for the design of foldamers, which are any polymers with a strong tendency to adopt a specific compact conformation. Peptides with cyclic dAAs preferentially adopt a helical structure. In contrast, peptides composed of acyclic dAAs with two bulky substituents form an extended planar conformation. In the current study, we developed dAAs with a cyclic acetal-side chain. The introduction of cyclic dAAs into peptides contributed to the stabilization of peptide secondary structures as a helix. Meanwhile, an acidic treatment of peptides resulted in a marked conformational change to a random structure probably due to the synergistic effects of structural changes (from cyclic to acyclic), hydrophilic changes (from an acetal to a diol), and the production of hydrogen-bond donors. The methodology developed in the current study will be applied to a variety of functional peptides and is expected for applications in peptide-based drug discovery.

Tittle
Low pH-triggering changes in peptide secondary structures

Paper: http://pubs.rsc.org/en/content/articlelanding/2017/ob/c7ob01374d    

Front cover: http://pubs.rsc.org/en/content/articlepdf/2017/ob/c7ob90130e?page=search    

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