ACP2 also known as Lysosomal acid phosphatase isoform 1. ACP2 is composed of two subunits, alpha and beta, and is chemically and genetically distinct from red cell acid phosphatase. it is a member of a family of distinct isoenzymes which hydrolyze orthophosphoric monoesters to alcohol and phosphate. Acid phosphatase deficiency is caused by mutations in the ACP2 (beta subunit) and ACP3 (alpha subunit) genes. Recombinant human ACP2, fused to His-tag at N-terminus, was expressed in E.coli.