A drug that is used to treat acute lymphoblastic leukemia (ALL) and is being studied in the treatment of some other types of cancer. It is an enzyme taken from the bacterium Escherichia coli (E. coli). It breaks down the amino acid asparagine and may block the growth of tumor cells that need asparagine to grow.

A hydrolase enzyme that converts L-asparagine and water to L-aspartate and NH3. EC 3.5.1.1.

An enzyme isolated from the bacterium Escherichia coli or the bacterium Erwinia carotovora with antileukemic activity. Asparaginase hydrolyzes L-asparagine to L-aspartic acid and ammonia in leukemic cells, resulting in the depletion of asparagine, inhibition of protein synthesis, cell cycle arrest in the G1 phase, and apoptosis in susceptible leukemic cell populations. Asparagine is critical to protein synthesis in leukemic cells; some leukemic cells cannot synthesize this amino acid de novo due to the absent or deficient expression of the enzyme asparagine synthase. The E. carotovora-derived form of asparaginase is typically reserved for cases of asparaginase hypersensitivity.