The ACY3 gene encodes Aminoacylase, a hydrolase enzyme responsible for removing the acyl group from acylated aromatic amino acids such as N-acetyl-L-histidine, N-acetyl-L-tyrosine, N-acetyl-L-phenylalanine, and S-benzyl-N-acetyl-L-cysteine. Of these, ACY3 has the highest affinity for the substrate S-benzyl-N-acetyl-L-cysteine.
The ACY3 enzyme exists as a mixture of catalytically active homodimers and homotetramers. Studies have found the enzyme to interact with the hepatitis C virus core protein; it is thus involved in the viral process and the xenobiotic metabolic process.