L-asparagine amidohydrolase (Escherichia coli) (L-asparaginase (EcA or EcAII))

L-asparagine amidohydrolase (Escherichia coli), commonly referred to as L-asparaginase or EcAII, is a homotetrameric enzyme of approximately 140 kDa composed of four identical subunits, each with about 330 amino acids[1][2]. It catalyzes the hydrolysis of the amino acid L-asparagine to L-aspartic acid and ammonia, playing a critical clinical role in the treatment of acute lymphoblastic leukemia by depleting plasma asparagine, which leukemic cells cannot synthesize independently[4][6]. Its structure is well-characterized, with two active sites formed by specific residues from each dimer interface, and its function is highly dependent on the active site's rigid and flexible loop regions[1][2]. L-asparaginase from E. coli is widely used as a first-line treatment in leukemia therapy and has additional applications in the food industry to reduce acrylamide formation[1]. Its use is limited by immunogenicity and toxicity, prompting development of less immunogenic or modified forms for improved safety profiles[4][6].

Other names

E. coli L-asparaginaseL-asparaginase II (E. coli)Asparaginase type II (E. coli)EcAIIASNase (generic, but often used)

Catalyzes the conversion of L-asparagine to L-aspartic acid and ammonia, depleting asparagine essential for leukemic cell survival[4][6]. Induces apoptosis in cells dependent on extracellular L-asparagine by inhibiting protein synthesis[4].