Studies on an extract of rat testicular microsomal fraction that catalyses the transformation of progesterone into 17-hydroxyprogesterone and androgens.
The supernatant obtained by centrifugation of Triton N-101-treated freeze-dried rat testicular microsomal fraction at 105000g(av.) for 2h transformed progesterone into testosterone via 17-hydroxypregn-4-ene-3,20-dione and androst-4-ene-3,17-dione. Hydroxylation at C-17 of 3beta-hydroxypregn-5-en-20-one and deoxycorticosterone was not observed. Non-haem iron protein, cytochrome P-450 and material with NADPH dehydrogenase activity were precipitated by 40% saturation of the supernatant with ammonium sulphate; however, it was not possible to establish the participation of these substances in the 17alpha-hydroxylase and side-chain-cleavage activities also present in the precipitate. The results of gel-filtration chromatography indicated that the Triton N-101 extract consisted primarily of a suspension of small particles of microsomes and that the progesterone 17-hydroxylase and the 17-hydroxypregn-4-ene-3,20-dione side-chain-cleavage enzyme were not in true solution.
D000728:Androgens / Q000096:biosynthesis*; D000731:Androstanes / Q000378:metabolism; D000818:Animals; D002845:Chromatography; D003580:Cytochromes / Q000032:analysis; D005612:Freeze Drying; D006908:Hydroxyprogesterones / Q000096:biosynthesis*; D066298:In Vitro Techniques; D007501:Iron / Q000032:analysis; D007659:Ketones / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000201:enzymology*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D010088:Oxidoreductases / Q000032:analysis; D011374:Progesterone / Q000378:metabolism*; D011506:Proteins / Q000032:analysis; D051381:Rats; D013501:Surface-Active Agents; D013737:Testis / Q000201:enzymology*; D013739:Testosterone / Q000096:biosynthesis; D014461:Ultracentrifugation
D000728:Androgens; D000731:Androstanes; D003580:Cytochromes; D006908:Hydroxyprogesterones; D007659:Ketones; D011506:Proteins; D013501:Surface-Active Agents; D013739:Testosterone; D011374:Progesterone; D007501:Iron; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases