The in vitro enzymic hydroxylation of steroid hormones. 1. Factors influencing the enzymic 11β-hydroxylation of 11-deoxycorticosterone

Abstract

The in vitro 11 beta-hydroxylation of 11-deoxycorticosterone (DOC) by ox-adrenocortical mitochondria was investigated. The reaction was shown to require concurrent oxidative phosphorylation, for which added citric acid cycle intermediates are oxidizable substrates. Fumarate is not specifically required and the reaction will proceed in the absence of added Mg ions. The prepn. of cell fractions containing steroid 11 beta-hydroxylating enzymes is discussed. Cofactor requirements are discussed in relation to energy-producing and steroid-hydroxylating reactions. Attention was drawn to the way in which certain steroids may influence their own hydroxylation by their effect on oxidative reactions of the citric acid cycle.