title: Solubilization and partial purification of steroid sulfatase of human placenta.
abstract: Steroid sulfatase of human placenta has been solubilized by treatment of the microsomal fraction with an amphoteric surface active agent, Miranol H2M and ultrasound. Criteria of solubility include non-sedimentation of the activity following centrifugation at 160,000 x g, its retention on Sepharose 6B and a single peak of activity after polyacrylamide gel electrophoresis. Enzyme activity was located in the same gel fractions for the two substrates tested; cholesterol sulfate and dehydroisoandrosterone sulfate. The addition of dithiothreitol was found necessary to maintain the stability of the enzyme indicating the presence of sulfhydryl groups in the molecule. A molecular weight of approximately 330,000 has been estimated from the elution volume of the enzyme system on a column of Sepharose 6B. It is believed that this protein represents a sulfatase enzyme complex composed of subunits with different specificities. From kinetic studies, a Km of 6.2 x 10(-5)M for the cleavage of dehydroisoandrosterone sulfate and a Km of 2 x 10(-6)M for the cleavage of cholesterol sulfate have been calculated.
mesh_terms: D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008970:Molecular Weight; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D012995:Solubility; D013256:Steroids / Q000378:metabolism; D013429:Sulfatases / Q000302:isolation & purification*; D013501:Surface-Active Agents
chemical_list: D013256:Steroids; D013501:Surface-Active Agents; D013429:Sulfatases