[71] Steroid-Transforming Enzymes

Affinity chromatography on adsorbents containing steroidal substrate analogs covalently linked to agarose promises to be an extremely valuable technique both for the purification of steroid-transforming enzymes, and for studies on their mechanism. When Pseudomonas testosteroni is grown on media containing certain steroids, crude extracts of lyophilized or sonically disrupted cells are a rich source of various induced steroid transforming enzymes. The isolation from these mixtures of discrete catalytic proteins, in purified form and uncontaminated by each other, has been a challenging task. The availability of such purified enzymes would greatly augment their suitability for the microanalysis and determination of steric configuration of steroids. Affinity techniques have indicated that the fl-enzymes do not bind strongly to steroids in the absence of NAD⁺, thus suggesting that these oxidations may involve an obligatory ordered addition in which the binding of NAD⁺ precedes that of the steroidal substrate.