Construction of multiple enzyme metal-organic frameworks biocatalyst via DNA scaffold: A promising strategy for enzyme encapsulation

The encapsulated enzyme system by metal-organic frameworks exhibited great potential in pharmaceuticals, enzyme fuel cells, and biocatalysis. However, the enzymatic activity and overall catalytic efficiency are severely hampered due to their enzyme leaching and causal enzyme location. Herein, for the first time, horseradish peroxidase (HRP) and glucose oxidase (GOx) used as model enzymes were cross-linked by rationally designed DNA scaffold network, and the multienzyme system has been successfully encapsulated into zeolite imidazolate framework-8 (ZIF-8). The prepared encapsulation multienzyme can efficiently suppress enzyme leaching from the MOFs skeleton, and the leaching amount was more than 10-times lower than the traditional MOFs encapsulation strategy. The well-tailored proximity and colocalization of cascade enzymes by the DNA scaffold network obviously improved the overall catalytic efficiency, enzymatic activity, and kinetic performance. The K-m and k(cat)/K-m for encapsulation multienzyme was 13.8 mM and 3.47 s(-1) mM(-1), which was 0.27-fold lower and 9.9-fold higher than those of free enzymes, respectively, indicating a better substrate affinity. Furthermore, the multienzyme system exhibited excellent stability and reusability compared with free enzymes and control groups, which could preserve 95% initial activity at 50 degrees C after 75 min incubation and more than 87% of the original activity after 14 cycles. Finally, the immobilized multienzyme exhibited enhanced performance to detect low concentration of glucose (0.4 mu M) with excellent selectivity. The outcome indicated that the encapsulated multienzyme could be extended for broad practical applications in biotechnology, biocatalysis, and biomedical engineering.