Magnetic-propelled Fe3O4–chitosan carriers enhance l-asparaginase catalytic activity: a promising strategy for enzyme immobilization

Abstract

Magnetic-propelled carriers comprising magnetic Fe₃O₄–chitosan nanoparticles were immobilized with L-asparaginase (L-ASNase). The enzyme displayed enhanced catalytic activity in a weak magnetic field, and thermal and pH stabilities. The conjugated L-ASNase presented higher thermostability and wider range of pH stability in comparison with those of free L-ASNase. Moreover, the reusability of conjugated L-ASNase significantly improved after immobilization and it retained 60.5% of its initial activity after undergoing 16 cycles. The conjugated L-ASNase maintained more than 50% and 48% initial activity after 4 weeks of storage at 4 °C and room temperature, respectively. Furthermore, we reveal that the activity of conjugated L-ASNase onto magnetic Fe₃O₄–chitosan particles increased by about 3-fold in the weak magnetic field at certain frequencies and flux density compared with that of free L-ASNase. Considering these excellent attributes, the magnetic-propelled mechanism in the transporting and activation of L-ASNase can be used by enhancing the catalytic activity, stability, and efficiency in vital implications for medicinal biotechnology.