ENZYMIC SYNTHESIS OF STEROID SULFATES XVI. SPECIFICITY AND REGULATION OF HUMAN ADRENAL HYDROXYSTEROID SULFOTRANSFERASE

Article abstract of DOI:10.1016/0039-128X(83)90023-5

Pure hydroxysteroid sulfotransferase (EG 2.8.2.2) of human adrenal glands possesses a wide substrate specificity towards steroids.This wide specificity has now been found to extend to simple alcohols; normal aliphatic alcohols from C3 onwards acting as substrates with C9 showing the highest rate.Increased rate was accompanied by a decrease in Km.In marked contrast to the sulfurylation of steroids such as dehydroepiandrosterone, which exhibit wave-like kinetics, the kinetics with simple alcohols were of the normal Michaelis-Menten type.By means of enzyme antibody and enzyme stability studies evidence was provided that one and the same enzyme was responsible for sulfurylation of hydroxyls on the 3- and 17-positions of steroids and simple alcohols.The data lend support to previous evidence that the enzyme controls the secretion of dehydroepiandrosterone sulfate via steroid-specific binding sites, enabling self-regulation in response to ACTH action.