Aspartoacylase is a hydrolase enzyme (EC 3.5.1.15, aminoacylase II, N-acetylaspartate amidohydrolase, acetyl-aspartic deaminase, acylase II, ASPA) that in humans is encoded by the ASPA gene. ASPA is responsible for catalyzing the deacylation of N-acetyl-l-aspartate (N-acetylaspartate) into aspartate and acetate. It is a zinc-dependent hydrolase that promotes the deprotonation of water to use as a nucleophile in a mechanism analogous to many other zinc-dependent hydrolases. It is most commonly found in the brain, where it controls the levels of N-actetyl-l-aspartate. Mutations that result in loss of aspartoacylase activity are associated with Canavan disease, a rare autosomal recessive neurodegenerative disorder.