Exhibits arylsulfatase activity and highly specific endoglucosamine-6-sulfatase activity. It can remove sulfate from the C-6 position of glucosamine within specific subregions of intact heparin. Binds 1 Ca(2+) ion per subunit. Optimum pH is 7.0-8.0. Also localized on the cell surface. Expressed at highest levels in the ovary, skeletal muscle, stomach, brain, uterus, heart, kidney and placenta. 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. May be due to a competing acceptor splice site. Belongs to the sulfatase family.