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

Abstract

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 cytochrome c (Cyt c) into dimethylimidazole-copper (Cu(Im) 2 ) by biomimetic mineralization, and constructed a bioinorganic hybrid material, termed Cyt c@Cu(Im) 2 . Encapsulated Cyt c in Cu(Im) 2 with a nanosheet structure exhibited significantly improved catalytic efficiency, enzymatic activity and kinetic performance. The catalytic efficiency (k cat /K m ) for Cyt c@Cu(Im) 2 was~20-fold higher compared to that of free Cyt c. 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-Cyt c@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.

Metal–Organic Frameworks as a Versatile Materials Platform for Unlocking New Potentials in Biocatalysis

“…Other than stability improvement, some research groups recently reported the biomimetic mineralization technique was also conducive to recycling performance and catalytic efficiency, bringing this technique one step closer to real applications in industry catalysis. [ 74–76 ] However, the inherited small pores of most MOFs may impede the diffusion of HRP substrates and could compromise the catalytic activity of HRP. To solve this problem, recently, Ge and co‐workers reported a method to encapsulate HRP in MOFs with engineered structural defects to enhance catalytic activity through microfluidic gradient mixing synthesis (Figure 3b).…”