Trp-Trp Cross-Linking: A Structure–Reactivity Relationship in the Formation and Design of Hyperstable Peptide β‑Hairpin and α‑Helix Scaffolds

Using model peptide β-hairpin scaffolds, the facile formation of a remarkably stable covalently cross-linked modification is reported in the tryptophan side chain, which confers hyperstability to the scaffold and displays a unique structure–reactivity relationship. This strategy is also validated to obtain a thermostable α-helix. Such imposition of conformational constraints can have versatile applications in peptide-based drug discovery, and this strategy may improve peptide bioavailability