EDTA-mimicking amino acid–metal ion coordination for multifunctional packings

Abstract

The coordination of biomolecules and metal ions plays vital roles in diverse metabolic activities. Yet, understanding their interaction mechanisms and developing potential applications are severely impeded due to the complexity of the coordinates and a lesser extent of integration. Mimicking this bio-coordination using minimalistic strategies and assembly into functional superstructures remains highly challenging. Here, we develop a bio-chelator using an amino acid, γ-carboxyglutamic acid (Gla), to complex with metal ions in a manner similar to EDTA. We revealed that the coordination induced co-crystallization by the uncommon “ladder, antiparallel” and “step, head–tail” interactions. Especially, the ringent system and the extensive interactions retained the functionalities of the metal ions, showing significant catalytic behavior with a maximal initial catalytic velocity of 5.08 × 10⁻⁵ mM s⁻¹ and a catalytic efficiency of 0.37 M⁻¹ s⁻¹, 23 and ∼19 fold higher than that of laccase, respectively. Furthermore, the bio-coordinated assemblies showed high piezoelectric properties with open-circuit voltage and short-circuit current of up to 1.5 V and ∼140 nA, respectively. These findings demonstrate that metabolic small molecules can be developed as EDTA-mimicking bio-chelators to coordinate with metal ions for various applications.