Fusarium sp. L-asparaginases: purification, characterization, and potential assessment as an antileukemic chemotherapeutic agent.

Asparaginases important role in the treatment of leukemia. It is part of chemotherapy in the treatment of leukemia in the last three decades. L-Asparaginase is isolated from Fusarium sp. isolated from soil and purified using ammonium sulfate precipitation and Sephadex G 100. Characterization of the crude enzyme revealed it is a metalloprotease inhibited by EDTA. Hg, Cd, and Pb also inhibited the enzyme. Mg, Zn, and Ca activated L-asparaginase. Furthermore, kinetic studies of purified enzyme were carried out. V and K were 0.031 M and 454 U/mL, respectively. The optimum temperature was 30 °C and the optimum pH was 7. Concerning substrate specificity, gelatin and casein in addition to L-asparagine were tested. The enzyme was found to be nonspecific that could hydrolyze all tested substrates at different rates. The maximum enzyme activity was recorded in the case of L-asparagine, followed by casein and gelatin, respectively. The molecular weight of L-asparaginase was 22.5 kDa. The antileukemic cytotoxicity assay of the enzyme against RAW2674 leukemic cell lines by MTT viability test was estimated. The enzyme exhibited antileukemic activity with IC of 50.1 UmL. The current work presents additional information regarding the purification and characterization of the enzyme produced by Fusarium sp. and its evaluation as a potential antileukemic chemotherapeutic agent.