– Aspartoacylase 3, also known as ACY3, N-acyl-aromatic-L-amino acid amidohydrolase (carboxylate-forming), Acylase III, Aminoacylase-3, Aspartoacylase-2, Aspartoacylase-2, HCV core-binding protein 1 and ASPA2, is a member of the Aspartoacylase subfamily. ACY3 plays an important role in deacetylating mercapturic acids in kidney proximal tubules and acts on N-acetyl-aromatic amino acids.ACY3 is located in the cytoplasm of S2 and S3 proximal tubules and the apical domain of S1 proximal tubules. ACY3 protein is also expressed at low levels in stomach, testis, heart, brain, lung and liver, and may function as an HCV (Hepatitis C virus) core binding protein.