Research Article
Priscila Lamb Wink, Heique Mar
Abstract
L-Asparaginase II from Erwinia carotovora may represent an important alternative therapy in the treatment of acute childhood lymphoblastic leukaemia, despite its promising lower glutaminase activity than Escherichia coli and Erwinia chrysanthemi L-asparaginases II, currently used in treatment of this disease. Here we describe cloning, expression, purification and determination of steady-state kinetic parameters for E. carotovora L-asparaginase II: with (AspSP) and without the signal peptide (AspMP). AspMP was purified to homogeneity by a single-step protocol with 91% yield, and AspSP by a two-step protocol with 28% yield. In addition, both enzymes presented similar high specific activities: 208.1 and 237.6 U mg-1, respectively. The Km and kcat values showed that AspMP has lower glutaminase activity than AspSP. Moreover AspMP is produced by a simpler purification protocol, and at higher yield. This process can be amenable to large scale production and be of interest to researchers and biopharmaceutical companies