Covalent Immobilization of recombinant Lepidium draba peroxidase on zinc metal-organic framework using glutaraldehyde

Lepidium draba peroxidase (LDP) belonging to the class III plant peroxidases that its amino acid sequence shows over 90% similarity with horseradish peroxidase (HRP).

In this study, after expression and purification of LDP, its immobilization conditions were optimized on the Zinc metal-organic framework (Zn-MOF) using glutaraldehyde as a cross-linking agent for firm binding. Then physicochemical properties, kinetic parameters and stability of the immobilized enzyme were compared with the free one.

The best conditions for enzyme immobilization with 67% yield were optimized at concentration of 0.02 g of Zn-MOF, 0.75mg/ml and 1.2 dM of glutaraldehyde, after 3h incubation. The results showed that the specific activity of the immobilized enzyme increased more than doubled that of free enzyme and its Km was reduced by 49% compared to the free one for TMB substrate. Also its kinetic stability reduced against pH and temperature in compared to the free enzyme.