Study on synthesis of rare ginsenoside Rh2 by one-step purification and immobilization of glycosyltransferase from magnetic Ni-based MOF

To solve the problem that free glycosyltransferase is difficult to isolate and reuse in ginsenoside Rh2 catalysis and synthesis. In this study, we developed a magnetic nickel-based metal-organic framework (MOF) material (Fe3O4/PDA@MOF) to enable the separation of recombinant glycosyl transferase (UGT) directly from crude enzyme solutions, while simultaneously immobilizing it by utilizing the specific adsorption of Ni2+ ions to His-tag. Our investigations demonstrated that the Fe3O4/PDA@MOF@UGT was successfully prepared, which not only maintained enzyme activity, but was reused by low-cost magnetic separation and exhibited enhanced enzyme loading and stability. Following thorough research and optimization, the immobilized enzyme achieved a rare ginsenoside Rh2 concentration of 69.68 µg/mL under optimal conditions, with an initial activity of 61.99 % after six cycles. This cost-effective, efficient, and sustainable biocomposite holds significant promise for industrial applications in enzyme purification and catalytic synthesis of ginsenoside.