Statistically optimized preparation of catalase immobilized magnetic nanoparticles

Background / Aim: Immobilization of enzymes over magnetic nanoparticles (MNPs) of Fe3O4 can make this preparation easily recoverable (with applied external magnetic field). Materials and Methods: Catalase enzyme was... [ view full abstract ]

Background / Aim: Immobilization of enzymes over magnetic nanoparticles (MNPs) of Fe3O4 can make this preparation easily recoverable (with applied external magnetic field).
Materials and Methods: Catalase enzyme was immobilized over MNPs (C-G-A-MNPs) via 3-aminopropyl triethoxy silane (APTES) functionalization (A-MNPs) and glutaraldehyde activation over A-MNPs (G-A-MNPs) using statistical method for optimization i.e. response surface method (RSM) for optimization important variables.
Results: Results obtained by experiment designed by RSM showed correlation coefficient 0.99, 0.97 and 0.98 (between actual and predicted value) was obtained with respect to catalase activity, protein loading and specific activity. Maximum catalase activity (32.1 ± 1.1 U mg-1 MNPs) and specific activity (97.7 ± 3.4 U mg-1 of loaded protein) was achieved with 64 mM of APTES, 10.97 µL of glutaraldehyde, 14.50 mg mL-1 of catalase enzyme, 67 min of time and 22.6 ºC of temperature. The stability studies showed the good retention of activity of C-G-A-MNPs (81.65±7.65 %) after 144 h at 4 oC in comparison to 7.87±2.15 % of free enzyme under similar conditions while there was retention of 64.34±8.15 % activity after 20 cycles.
Discussion: RSM is a method supported the multi-variable non-linear model, it's helpful in evaluation and perceiving the interactions of the varied parameters influencing the method. This variable approach showed advantage in terms of reductions within the range of experiments, improved applied math interpretation and reduced time necessities.
Conclusion: The enzyme immobilized preparation prepared by statistically optimization was found to be suitable and effective for reuse in its different applications.
Key words: Magnetic nanoparticles, response surface methodology, enzyme immobilization, surface functionalization, central composite design, characterization, recyclability, stability