A preorganized β-amino acid bearing a guanidinium side chain and its use in cell-penetrating peptides†
Abstract
A cyclic β-amino acid (APCGu) bearing a side-chain guanidinium group has been developed. The APCGu residue was incorporated into an α/β-peptide based on the Tat(47–57) fragment, leading to an oligomer with substantial helicity in methanol that enters HeLa cells much more readily than does the corresponding Tat α-peptide.