Human Placental Steryl-Sulfatase. Enzyme Purification, Production of Antisera, and Immunoblotting Reactions with Normal and Sulfatase-Deficient Placentas

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Abstract
The steryl-sulfatase of normal human placental microsomes was solublilized and enriched about 350-fold. Chromatography on Sepharose 6B of the purified enzyme preparation revealed a single protein peak which eluted according to an apparent molecular mass of 270 .+-. 30 kDa: when electrophorized on sodium dodecyl sulfate polyacrylamide gel the sulfatase migrated according to a molecular mass of 64 .+-. 4 kDa. Estrogensulfatase activity was co-purified with the steryl-sulfatase activity; obviously, both activities belong to the same enzyme species. The purified sulfatase was injected into three rabbits. Antisera produced by the rabbits yielded a single sharp immunoprecipitation line in Ouchterlony double diffusion experiments when tested with the isolated sulfatase or with a solubilized microsomal fraction of normal placentas. The activity of sulfatase preparations incubated with antiserum was precipitated by addition of polyethylene glycol followed by centrifugation; none of the antibodies reacting with the sulfatase therefore appeared to interfere with its enzymatic activity. Using these antisera, steryl-sulfatase protein could be detected by immunoblotting analysis in solubilized microsomal fractions of normal placentas but not in solubilized microsomal fractions of three steryl-sulfatase activity-deficient placentas. This finding argues in favour of human placental steryl-sulfatase deficiency being due to extremely diminished or absent enzyme protein in the placenta.