High activity and stability of immobilized enzymes have been constant pursuits and critical challenges for decades. Herein, Cytochrome c (peroxidase, Cyt c) and its corresponding enzyme mimic (Pd nanoparticles) were combined and successfully embedded into a zeolitic imidazolate framework-8 (ZIF-8) to enhance the enzymatic catalytic performance using a biomimetic mineralization approach. Owing to allosteric effects of Cyt c-Pd complexes, the as-synthesized Cyt c-Pd@ZIF-8 composites exhibit an increased turnover number (approximately 2.4-fold for kcat) and an enhanced catalytic efficiency (approximately 2.3-fold for kcat/KM) compared to free Cyt c; also the shielding effect of ZIF-8 endows enzyme with improved resistance against harsh conditions (e.g. high temperatures and organic solvents). The strategy, which integrates enzyme with its enzyme mimic derived from transition metal nanoparticles to enhance enzymatic catalytic performances, may provide a versatile and facile technique for designing highly efficient and multi-functional bio-catalysts.
Keywords: Cytochrome c; Enzyme immobilization; Pd nanoparticles; Zeolitic imidazolate framework.
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