Biomimetic Mineralization of Cytochrome c Improves the Catalytic Efficiency and Confers a Functional Multi-Enzyme Composite

The encapsulated enzyme system by metal-organic frameworks (MOFs) exhibits great potential in biofuel cells, pharmaceuticals, and biocatalysis. However, the catalytic efficiency and the enzymatic activity are severely hampered due to enzyme leaching and deficiency of storage stability. In this study, we immobilized cytochromec(Cytc) into dimethylimidazole-copper (Cu(Im)2) by biomimetic mineralization, and constructed a bioinorganic hybrid material, termed Cytc@Cu(Im)2. Encapsulated Cytcin Cu(Im)2with a nanosheet structure exhibited significantly improved catalytic efficiency, enzymatic activity and kinetic performance. The catalytic efficiency (kcat/Km) for Cytc@Cu(Im)2was ~20-fold higher compared to that of free Cytc. Moreover, the increased activity was not affected by long-term storage. Based on this system, we further constructed a multi-enzyme composite with glucose-oxidase (GOx), termed GOx-Cytc@Cu(Im)2, which exhibited greatly improved enzymatic activity, stability, and excellent selectivity for the detection of low concentrations of glucose. This strategy may provide new insights into the design of enzymes with high activity and stability, as well as the construction of multi-enzyme systems.Keywords:enzymatic immobilization;biomimetic mineralization;multi-enzyme;bioinorganic hybrid material;biosensors