title: Effect of some agents on the activity of cell-free progesterone 11 alpha-hydroxylase and 11 beta-hydroxylase from Aspergillus niger 12Y.
abstract: The effect of some agents on the activity of cell-free progesterone 11 alpha-hydroxylase and 11 beta-hydroxylase from Aspergillus niger 12Y was studied. Calcium chloride, sodium chloride, magnesium sulphate, copper sulphate, and EDTA inhibited 11 alpha-hydroxylase and 11 beta-hydroxylase, while mercuric chloride inhibited only 11 alpha-hydroxylase. Inhibition of both the enzymes was also brought about by iodine, p-chloromercuribenzoate, iodoacetic acid, maleic acid, and cystine as well as potassium ferricyanide for 11 alpha-hydroxylase. Reduced glutathione and cysteine-HCl brought about activation of 11 alpha-hydroxylase and 11 beta-hydroxylase. The probability of the presence of reactive sulfhydryl groups in the active sites of both enzymes was discussed. Urea inhibited both fungal progesterone hydroxylases, probably due to enzyme protein denaturation.
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D002474:Cell-Free System; D002729:Chloromercuribenzoates / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006900:Hydroxylation; D008278:Magnesium Sulfate / Q000494:pharmacology; D011374:Progesterone / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology; D013250:Steroid Hydroxylases / Q000378:metabolism*; D014508:Urea / Q000494:pharmacology
chemical_list: D002729:Chloromercuribenzoates; D012965:Sodium Chloride; D011374:Progesterone; D008278:Magnesium Sulfate; D014508:Urea; D004492:Edetic Acid; D013250:Steroid Hydroxylases