The First Water-Soluble 310-Helical Peptides

Two water-soluble 310-helical peptides are synthesized and fully characterized for the first time. The sequence of these terminally blocked heptamers comprises two residues of the Cα-trisubstituted α-amino acid 2-amino-3-[1-(1,4,7-triazacyclononyl)]propanoic acid and five residues of a Cα-tetrasubstituted α-amino acid (either α-aminoisobutyric acid or isovaline). Using CD and NMR techniques we were able to show that both heptapeptides are well structured in water, and that the type of conformation adopted is indeed the ternary 310-helix.