Purification and properties of arylsulfatase C from human placenta

Arylsulfatase C (ASC) was purified about 1,000-fold from human placenta. The major steps in the procedure included chromatography on Con A-Sepharose and Bio-Gel A-1.5 m. The purified enzyme was homogeneous by sodium dodecylsulfate/polyacrylamide gel electrophoresis. The native enzyme has an apparent molecular weight of 238,000 resulting from three identical subunits of 78,000 daltons. The purified enzyme hydrolyzes the artificial substrate p-nitrophenyl sulfate (NPS), and the two natural substrates estronesulfate (ES) and dehydroepiandrosterone sulfate (DHEAS), the ratio of these three activities being constant throughout the purification. ES and DHEAS are powerful competitive inhibitors of the enzymatic hydrolysis of NPS. ASC, ESase and DHEASase activities show the same thermal stability. These results strongly suggest that a single enzyme is responsible for the hydrolysis of the two natural and the artificial substrates.