PURIFICATION OF TESTOSTERONE 5-ALPHA-REDUCTASE FROM HUMAN PROSTATE BYA 4-STEP CHROMATOGRAPHIC PROCEDURE

Nuclear membrane bound testosterone 5 alpha-reductase solubilized in a ctive form from human prostatic tissue by 0.5% n-octyl beta-D-glucopyr anoside was purified by a four-step chromatographic procedure includin g DEAE-Trisacryl ion exchange, hydroxylapatite adsorption, testosteron e-Sepharose affinity and Sepharose 4B gel filtration. A purification o f approximately 30-fold was achieved judging from the increase in the specific enzymatic activity. We have purified the acinic pH-optimum 5 alpha-reductase type 2 isoenzyme. The apparent molecular weight of the purified enzyme was estimated as 42,000 by SDS-PAGE. At the same time we isolated a 38 kDa protein characterized by a real affinity for tes tosterone and by a possible association to the 5 alpha-reductase enzym e.