Characteristics of Penicillin G Acylase Immobilized onto Iron Oxide Nanoparticles

Penicillin G acylase was immobilized onto iron oxide nanoparticles coated with polyethyleneimine and then cross linked with glutaraldehyde solution. The FTIR spectrum of immobilized enzyme showed peak at 1648cm-1 which can be attributed to the C=N bonds of Schiff’s base linkage formed between glutaraldehyde and amino group of penicillin G acylase. By considering the FTIR spectrum of nano particle coated with polyethyleneimine, adsorption of penicillin G acylase has taken place and then glutaraldehyde cross linked enzyme onto activated support. Catalytic properties of nano penicillin G acylase were improved upon immobilization as compared to its free counterpart. The optimal pH and temperature were determined to be 7.0, 10.0, 50 and 75ºC for free and immobilized penicillin G acylase, respectively. Thermal stabilities of both nano and free penicillin G acylase were studied .The Km value of immobilized nanozyme was calculated from Lineweaver Burck plot to be 0.23 μM while that of free penicillin G acylase was 0.28μM. In this way nano penicillin G acylase with improved catalytic properties was developed as compared to its soluble counterpart.