Supramolecular assembly of β-cyclodextrin-modified gold nanoparticles and Cu, Zn-superoxide dismutase on catalase

A bienzymatic supramolecular nanoassembly containing catalase and Cu, Zn-superoxide dismutase is reported. Catalase was hydrophobically modified with 1-adamantanecarboxylic acid and then immobilized on β-cyclodextrin-coated gold nanospheres via supramolecular associations. The bienzymatic nanocatalyst was further prepared by co-immobilization of β-cyclodextrin-modified superoxide dismutase. Supramolecularly immobilized catalase and superoxide dismutase retained 73 and 35%, respectively, of their initial specific activity. The range of optimum pH for catalase was increased from 7.0–7.5 to 6.5–7.5, and the thermal stability improved by 7 °C after co-immobilization. Superoxide dismutase was 90-fold more resistant to inactivation by 100 mM H2O2 after bienzymatic immobilization with catalase on metal nanoparticles.