Abstract
The conformational control of molecular architectures bearing functional groups in a defined spatial arrangement is of great interest for the development of tools that can be used in a range of fundamental and applied systems including material and biomedical science. Peptides offer great functional diversity and remarkably attractive routes of synthesis, but they do not allow molecular shape control to access such scaffolds.We have developed a straightforward strategy for converting peptide sequences into γ-lactam-containing oligomers and showed the propensity of these molecules to adopt a ribbon-like secondary structure [1]. The periodic distribution of the functional groups on either side of the ribbon plane is simply encoded by the peptide sequence. They exhibit higher cellular uptake and protease resistance than well-established cell-penetrating peptides (CPPs) such as penetratin and can vectorise bioactive molecules [2].We have currently applied this strategy starting from α/β-peptides yielding heterogeneous backbones alternating α-amino-γ-lactams (Agl) and β-amino acids. Such oligomers adopt an original 12-helix with an elliptical cross section, stabilised by a zigzag hydrogen bond network. Interestingly, they show unexpected solubility in water despite the exclusive presence of highly hydrophobic side chains (e.g. Phe, Trp, Ile side chains). The origin of this remarkable solubility in aqueous media is still under investigation.References1. Martin V. et al (2015). Angew. Chem. Int. Ed., 54, 13,966–13,970.2. Vezenkov L. et al (2017). ChemBioChem, 18, 2110–2114.