L-
asparaginase from bacteria has been used in treatment of
acute lymphoblastic leukemia. The aim of this study was to purify and characterize L-
asparaginase from Phaseolus vulgaris seeds instead of microbial sources. L-
asparaginase was purified to apparent homogeneity. The
enzyme has molecular mass of 79 kDa. The purified
asparaginase had very low activity toward a number of
asparagine and
glutamine analogues. L-
asparaginase was free from
glutaminase activity. Kinetic parameters, Km and Vmax of purified
enzyme, were found to be 6.72 mM and 0.16 μM, respectively. The
enzyme had optimum pH at 8.0. The
enzyme showed high stability at alkaline pH (pH 7.5-9.0) when incubated for up to 24 h. L-
asparaginase had the same temperature optimum and thermal stability at 37°C. K(+) was able to greatly enhance the activity of
asparaginase by 150% compared with other metals tested. In conclusion, L-
asparaginase showed no
glutaminase activity and good stability over a wide range of physiological conditions, and thus it could be used as a potential candidate for treatment of
acute lymphoblastic leukemia.