The use of 4,4,4-trifluorothreonine to stabilize extended peptide structures and mimic β-strands

Pentapeptides having the sequence R-HN-Ala-Val-X-Val-Leu-OMe, where the central residue X is L-serine, L-threonine, (2S,3R)-L-CF₃-threonine and (2S,3S)-L-CF₃-threonine were prepared. The capacity of (2S,3S)- and (2S,3R)-CF₃-threonine analogues to stabilize an extended structure when introduced in the central position of pentapeptides is demonstrated by NMR conformational studies and molecular dynamics simulations. CF₃-threonine containing pentapeptides are more prone to mimic β-strands than their natural Ser and Thr pentapeptide analogues. The proof of concept that these fluorinated β-strand mimics are able to disrupt protein-protein interactions involving β-sheet structures is provided. The CF₃-threonine containing pentapeptides interact with the amyloid peptide Aβ_1-42 in order to reduce the protein-protein interactions mediating its aggregation process.