Argininosuccinate lyase (ASL)

Argininosuccinate lyase is a cytosolic enzyme that catalyzes the reversible cleavage of argininosuccinate to produce arginine and fumarate, a critical step in the urea cycle and arginine biosynthesis[1][3][8][9]. The enzyme functions as a homotetramer, with each monomer contributing to the formation of active sites necessary for catalysis[1][2]. Deficiency or mutations in the *ASL* gene disrupt the urea cycle, leading to toxic ammonia buildup, neurological damage, and the genetic disorder argininosuccinic aciduria[3][5][7]. Argininosuccinate lyase also influences nitric oxide synthesis by supporting arginine availability, making it relevant to vascular biology[3]. Management of ASL deficiency primarily involves dietary control, ammonia-scavenging drugs, and L-arginine supplementation[3].

Other names

ASLArgininosuccinaseArginosuccinaseARLY_HUMANArgininosuccinate lyase (EC 4.3.2.1)

L-arginine supplementation provides the downstream product that is deficient in ASL deficiency, bypassing the metabolic block caused by reduced enzyme activity.