Purification and characterization of L-asparaginase from erwinia carotovora

ABSTRACT

An L-asparaginase from Erwinia carotovora was successively purified by ammonium sulfate precipitation, DEAE-cellulose and Sephacryl S-200 columns. The specific activity of the L-asparaginase was increased approximately 55-fold, from 15.5 to 852 U/mg proteins. SDS-PAGE showed that the purified L-asparaginase was homogeneous and the molecular weight was about 115 kDa. The isoelectric point [pI] of the enzyme was about 5.9. Characterization of the enzyme exhibited optimum pH and temperature of 8.4 and 40°C, respectively. The purified enzyme is able to prolong its thermal stability up to 50°C. A Lineweaver-Burk analysis showed a K[m] value of 0.154 mM and V[max] of 41.67 U. The purified enzyme was rich in glycine, alanine, glutamic acid and aspartic acid