Displays arylsulfatase activity at acidic pH towards artificial substrates, such as p-nitrocatechol sulfate and also, but with a lower activity towards p-nitrophenyl sulfate and 4-methylumbelliferyl sulfate (PubMed:18283100, PubMed:29300381). Catalyzes the hydrolysis of the 3-sulfate groups of the N-sulfo-D-glucosamine 3-O-sulfate units of heparin (PubMed:22689975). an aryl sulfate + H2O = a phenol + H(+) + sulfate Hydrolysis of the 3-sulfate groups of the N-sulfo-D-glucosamine 3-O-sulfate units of heparin. Binds 1 Ca(2+) ion per subunit. Inhibited by phosphate. The phosphate forms a covalent bond with the active site 3-oxoalanine. Optimum pH is 5.4. Most efficient at 45-50 degrees Celsius. The 63-kDa precursor protein localizes to pre-lysosomal compartments and tightly associates with organelle membranes, most likely the endoplasmic reticulum. In contrast, proteolytically processed fragments of 34-, 18- and 10-kDa are found in lysosomal fractions and lose their membrane association. Widely expressed, with very low expression in brain, lung, heart and skeletal muscle. N-glycosylated (PubMed:18283100). N-glycosylated with both high mannose and complex type sugars (By similarity). The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity. The 63-kDa precursor undergoes proteolytic processing in two steps, yielding two fragments in the first step (apparent molecular masses of 44 and 18 kDa) (PubMed:25135642). In the second step, the 44-kDa fragment is processed further to the 34- and 10-kDa chains. The 10-kDa chain is a cleavage product of the 44-kDa fragment but linked to the 18-kDa chain through a disulfide bridge (PubMed:25135642). The disease is caused by variants affecting the gene represented in this entry. Belongs to the sulfatase family. Extended N-terminus.