Purification, Characterization and Comparison between Two New L-asparaginases from PG03 and PG04.

Background: L-asparaginase has been used as a chemotherapeutic agent in treatment of lymphoblastic leukemia. In the present investigation, sp. PG03 and sp. PG04 were studied.

Methods: L- asparaginases were produced using different culture media and were purified using ion exchange chromatography.

Results: Maximum productivity was obtained when asparagine was used as the nitrogen source at pH 7 and 48 h after cultivation. New intracellular L-asparaginases showed an apparent molecular weight of 25 kDa and 30 kDa by SDS-PAGE respectively. These enzymes were active in a wide pH range (3-9) with maximum activity at pH 6 for PG03 and pH 7 for PG04 L-asparaginase. PG03 enzyme was optimally active at 37 ˚C and PG04 maximum activity was observed at 40˚C. Kinetic parameters and of both enzymes were studied using L-asparagine as the substrate. Thermal inactivation studies of PG03 and PG04 L-asparaginase exhibited t of 69.3 min and 34.6 min in 37 ˚C respectively. Also T and ∆G of inactivation were measured for both enzymes.

Conclusion: The results revealed that both enzymes had appropriate characteristics and thus could be a potential candidate for medical applications.