An enzyme isolated from the bacterium Escherichia coli or the bacterium Erwinia carotovora. Asparagine is critical to protein synthesis in leukemic cells, which cannot synthesize this amino acid due to the absence of the enzyme asparagine synthase. Asparaginase hydrolyzes L-asparagine to L-aspartic acid and ammonia, thereby depleting leukemic cells of asparagine and blocking protein synthesis and tumor cell proliferation, especially in the G1 phase of the cell cycle. This agent also induces apoptosis in tumor cells. The E. carotovora-derived form of asparaginase is typically reserved for cases of hypersensitivity. (NCI04) Drug name confusion