:N-acetylgalactosamine-4-sulfatase

{{Infobox enzyme

| Name = N-acetylgalactosamine-4-sulfatase

| EC_number = 3.1.6.12

| CAS_number = 55354-43-3

| GO_code =

| image =

| width =

| caption =

}}

N-acetylgalactosamine-4-sulfatase (EC 3.1.6.12, chondroitinsulfatase, chondroitinase, arylsulfatase B, acetylgalactosamine 4-sulfatase, N-acetylgalactosamine 4-sulfate sulfohydrolase) is an enzyme with systematic name N-acetyl-D-galactosamine-4-sulfate 4-sulfohydrolase.{{cite journal | vauthors = Farooqui AA | title = The desulphation of hexosamine sulphates by arylsulphatase B | journal = Experientia | volume = 32 | issue = 10 | pages = 1242–4 | date = October 1976 | pmid = 976430 | doi = 10.1007/BF01953071 | s2cid = 26640171 }}{{cite journal | vauthors = Gorham SD, Cantz M | title = Arylsulphatase B, an exo-sulphatase for chondroitin 4-sulphate tetrasaccharide | journal = Hoppe-Seyler's Zeitschrift für Physiologische Chemie | volume = 359 | issue = 12 | pages = 1811–4 | date = December 1978 | pmid = 738706 | doi = 10.1515/bchm2.1978.359.2.1811 }}{{cite journal | vauthors = Tsuji M, Nakanishi Y, Habuchi H, Ishihara K, Suzuki S | title = The common identity of UDP-N-acetylgalactosamine 4-sulfatase, nitrocatechol sulfatase (arylsulfatase), and chondroitin 4-sulfatase | journal = Biochimica et Biophysica Acta | volume = 612 | issue = 2 | pages = 373–83 | date = April 1980 | pmid = 7370276 | doi = 10.1016/0005-2744(80)90120-5 }} It catalyses the following reaction:

: Hydrolysis of the 4-sulfate groups of the N-acetyl-D-galactosamine 4-sulfate units of chondroitin sulfate and dermatan sulfate.

It also acts on N-acetylglucosamine 4-sulfate.