Amino acid-based tweezers: The role of turn-like conformation in the binding of copper(II)

► Small molecular amino acid-based tweezers are synthesized and characterized. ► They form complexes of 1:1 stoichiometry with Cu(II). ► LCu2 + species are predominant at wide pH range, including physiological. ► Stability constants are comparable with those of peptides with His in sequence. ► The importance of turn-like conformation for the Cu(II) binding is confirmed.