Enhanced catalytic activity and reusability of sucrose phosphorylase@magnetic nanoparticles by surface-coating amorphous ZIF-67

Sucrose phosphorylase (SPase) is a highly efficient glycosyltransferase which has a wide range of substrate specificity and excellent application prospects in the cosmetics, food, and medicine fields. The application of free SPase is limited due to its high cost, poor stability and poor reusability. Immobilization of enzymes can solve these problems. In this study, SPase was firstly immobilized by magnetic nanoparticles (MNPs) and surface-coating amorphous ZIF-67 for enhancing catalytical activity and reusability. ZIF-67@SPase@MNPs with MNPs core and ZIF-67 shell was characterized by TEM, SEM, XRD, FT-IR and VSM. Compared with free SPase, the catalytic activity of ZIF-67@SPase@MNPs increased by 30 %. Coated with amorphous ZIF-67, the immobilized enzyme retained 70 % relative activity after 12 cycles and 80 % relative activity after 15 days of storage. In addition, ZIF-67@SPase@MNPs had strong magnetic properties and the saturation magnetization was 52.07 emu/g. Surface-coating amorphous ZIF-67 on SPase@MNPs is a promising method for immobilizing enzymes, which can improve catalytic activity and reusability, therefore showing great application potential in biocatalysts and product separation. It has a good application prospect in the production of high viscosity glycosides.