Supramolecular DNA/Amino Acids-based Oxidase-mimetic Nanocatalyst Exhibiting Drug Degradation Capability

Abstract

Developing efficient and environmental benign approach for the remediation of antibiotic pollutants has become paramount research imperative, since the extensive use of antibiotics has raised serious concerns due to their potential to induce antibiotic resistance and disrupt ecological balance. In this work, we report the self-assembly of fluorenylmethyloxycarbonyl-lysine (Fmoc-K) aggregates with natural calf thymus DNA (CT-DNA) and Cu2+ to construct catalyst that possesses copper-dependent active sites, mirroring the catalytic function of laccase, an oxidase known for its ability to degrade phenolic antibiotics. Structural characterizations, including circular dichroism, fluorescence spectra, transmission electron microscopy (TEM) and electrons paramagnetic resonance (EPR), indicate the association of Fmoc-K to DNA components, facilitating the coordination of Cu2+ to both. Kinetic studies revealed that the Fmoc-K/CT-DNA/Cu²⁺ complex exhibited over 13-fold higher catalytic efficiency than either CT-DNA/Cu²⁺ or Fmoc-K/Cu²⁺ alone. Notably, CT-DNA not only serves as a structural scaffold but also promotes the access of the antibiotic substrates (including doxorubicin and tetracycline) to the copper center due to its binding affinity for these antibiotics, thereby facilitating efficient oxidative degradation. This work offers a promising strategy for constructing high-performance, environmentally responsive metalloenzyme mimics for pollutant remediation.