Turn residues in beta-hairpin peptides as points for covalent modification.

Beta-turns are important sites for protein-protein and protein-peptide interactions, but little research has explored synthetic modifications of turn residue side-chains in a beta-hairpin peptide. To this end, beta-hairpin peptides were synthesized containing the type I' turn sequence Val-Asn-Gly-Lys with modifications at Asn and Lys. We found that these variations impose a small penalty, demonstrating that beta-turns are capable of displaying a range of functionality, which may be exploited for biomolecular recognition and medicinal applications. [structure: see text]