L-asparaginase is an anti-tumor enzyme used for the treatment of Acute Lymphoblastic Leukemia (ALL), a disease caused by expansion of lymphoid blasts in bone marrow and blood. L-asparaginase is produced by a variety of sources like bacteria, fungus, yeast and plants. S. nigrum is one potent source of L-asparaginase with enzyme activity of 52 IU/ml. To increase the stability and shelf-life of L-asparaginase, it was immobilized on different nanoparticles like magnetic, ZnO, starch and alginate. The synthesized nanoparticles were characterized using UV-visible spectroscopy, Fluorescence spectroscopy and Scanning Electron Microscopy (SEM). It was found that λmax of magnetic nanoparticles was 380 nm, ZnO nanoparticles was 360 nm and for starch and alginate nanoparticles it was 280 nm and 400 nm respectively. FTIR spectra showed different vibrational and stretching bonds involved during formation of nanoparticles. The size of magnetic nanoparticles was 25 nm and for ZnO nanoparticles was 300 nm after immobilization of L-asparaginase. The immobilization of L-asparaginase on starch and alginate nanoparticles was not found to be efficient. Magnetic nanoparticles were further characterized kinetically. The Km and Vmax for L-asparaginase loaded magnetic nanoparticles was 7.11 mM and 100 μM/min respectively. The optimum pH was 8.0 and temperature was 50 ℃. The metal ions have both inhibitory and enhancing effect on Lasparaginase activity chelators mostly enhanced the activity. Therefore, L-asparaginase immobilized on magnetic nanoparticles could be further used in applications like drug delivery.
