Displays arylsulfatase activity at acidic pH towards the artificial substrate p-nitrocatechol sulfate (PubMed:25135642). 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. 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. Highly expressed in the spleen, kidney, liver, brain, and testis (at protein level). N-glycosylated with both high mannose and complex type sugars. 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). 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. Mice accumulate heparan sulfate in visceral organs and the central nervous system and develop neuronal cell death and behavioral deficits (PubMed:22689975). This accumulated heparan sulfate exhibits unique non-reducing end structures with terminal N-sulfoglucosamine-3-O-sulfate residues (PubMed:22689975). Belongs to the sulfatase family.