Polyaniline nanofiber as a novel immobilization matrix for the anti-leukemia enzyme l-asparaginase

In this study, polyaniline nanofibers are used as a novel immobilization support and evaluated using l-asparaginase as a model protein enzyme for precise investigation of the immobilized state of enzymes as well as its functional activity on polyaniline nanofiber surfaces at different concentrations. The supported enzyme has been characterized by XPS, XRD, TEM and FTIR, and the effect of polymer nanofiber conformations on the enzymatic activity is discussed in detail. Immobilized l-asparaginase showed greater stability towards decomposition/denaturation at different temperatures and pH conditions compared to the free enzyme. The calculated Km values are 1.809 and 3.705 mM L−1 for immobilized l-asparaginase, respectively, which are 2.05-fold lower in magnitude in comparison with the value obtained for free l-asparaginase; the Vmax values for immobilized and free l-asparaginase are 90.57 and 48.04 μM min−1 mg−1 respectively.