A "soluble" form of sterol sulphate sulphohydrolase from cell nuclei of human placenta tissue--examinations with oestrone sulphate as substrate.
DN-ase digestion of the nuclear envelope-chromatin complex of the cell nuclei preparations from human placenta, released a soluble form of sterolsulphohydrolase. The enzyme revealed three pH optima, at 4.0, 6.2 and 7.4. The Km value was 4.16 +/- 1.44 x 10(-5) M. The molecular mass determined by gel filtration on Bio-gel A 15 m was 406 kDa. The enzyme is sensitive to -SH group reacting reagents such as cysteine, p-chloromercuribenzoate and iodoacetamide. Oxidized and reduced forms of NAD, FAD, dithiothreitol and glutathione moderately inhibited enzyme activity. Ascorbic acid (reduced and oxidized) exerted slight activation. The enzyme was insensitive to phosphate ions.
Mikoøaj Kopernik University, Biochemistry Department, Toruń, Poland.
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J
Gniot-Szulzycka
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Drywa
D001192:Arylsulfatases / Q000378:metabolism*; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000201:enzymology*; D003851:Deoxyribonucleases / Q000378:metabolism; D004970:Estrone / Q000031:analogs & derivatives* / Q000378:metabolism; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010920:Placenta / Q000201:enzymology* / Q000648:ultrastructure; D011247:Pregnancy; D012995:Solubility; D043266:Steryl-Sulfatase; D013379:Substrate Specificity
D004970:Estrone; D003851:Deoxyribonucleases; D001192:Arylsulfatases; D043266:Steryl-Sulfatase; C017296:estrone sulfate