Synthesis of water-soluble boronic acid functional magnetic nanoparticles and their use in L-asparaginase immobilization

L-asparaginase is an enzyme-drug used in the treatment of Acute Lymphoblastic Leukemia (ALL) and some lymphomas. L-asparaginase, which is used in these treatments, has some side effects resulting from its isolation from bacteria and limiting its use. To prevent this situation, L-asparaginases are available in PEG-conjugated form. However, various magnetic nanocarrier systems are being developed to make L-asparaginase more biocompatible, to ensure that it reaches the desired region more effectively, and to examine its kinetic properties. The aim of this study is to synthesize boron-derived magnetic nanoparticles to immobilize L-asparaginase and to examine the kinetic properties of the immobilized enzyme. For this purpose, magnetic iron oxide nanoparticles were synthesized and modified with boronic acid to be used as carrier matrix. All materials obtained within the scope of the study were characterized structurally and morphologically. In addition, the optimum parameters (pH, temperature), thermal stability, storage stability, reusability and kinetic parameters of the immobilized enzyme were investigated and compared with the free enzyme. Moreover, the activity of the immobilized enzyme under weak magnetic field was investigated. The optimum pH and temperature of the free enzyme were found to be 8.5 and 45 °C, respectively, while it was found to be 7.5 and 40 °C for the immobilized enzyme. Moreover, even after 10 cycles of use, the immobilized enzyme retained 54% of its initial activity. In kinetic studies, Km values for free enzyme and for immobilized enzyme were found to be 10.376±0.5 and 7.06±2.99 mM, respectively, and Vmax was found to be 138.88±2.64 and 121.95±1.070 µmol/min, respectively. In addition, when a magnetic field of 10 Hz and a magnetic flux of 20 mT were applied, it was observed that the activity increased approximately 3,2 and 4,3 times, respectively. As a result, functional boron-derived magnetic nanocarriers with high water solubility were prepared for use in L-asparaginase immobilization, L-asparaginase enzyme was immobilized and the activity of the immobilized enzyme was increased in a weak magnetic field. Keywords: Boronic acid, L-asparaginase, Enzyme Immobilization, Nanocarriers, Magnetic nanoparticle