[Steroid-transforming enzymes from microorganisms. XII. Induction characteristics of the 4-en-3-oxosteroid: (acceptor)-1-en-oxidoreductase in Nocardia opaca].

17 alpha-Methyltestosterone and the corresponding 1(2)-dehydrocompound (Dianabol) are efficient inducers of the 4-en-3-oxosteroid: (acceptor)-1-en-oxidoreductase from Nocardia opaca. After a lag period of 4 hours the enzyme activity increases rapidly. During the induction the steroids are completely metabolized causing a drastical drop of specific enzyme activity. Using a fixed induction time the optimal steroid concentration and the temperature characteristic were found out. The influence of the concentration of the steroid water suspension on the induction effect is discussed to be dependent on the velocity of the dissolving of the steroid particles. Chloramphenicol and streptomycin are powerful inhibitors of the induction process.