Arylsulfatase A

Arylsulfatase A (ARSA) is also known as Cerebroside-sulfatase, is a lysosomal enzyme, which belongs to the sulfatase family. ARSA can be cleaved into the following 2 chains: Arylsulfatase A component B and Arylsulfatase A component C. ARSA is homodimer at neutral pH and is homooctamer at acidic pH. ARSA exists both as a single chain of 58 kDa (component A) or as a chain of 50 kDa (component B) linked by disulfide bond(s) to a 7 kDa chain (component C). Arylsulfatase A binds 1 calcium ion per subunit. The catalytic activity of ARSA is ¡°A cerebroside 3-sulfate + H2O = a cerebroside + sulfate¡±, and is inhibited by phosphate. The phosphate forms a covalent bond with the active site 3-oxoalanine.