{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,22]],"date-time":"2026-09-22T04:48:01Z","timestamp":1790052481062,"version":"4.0.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1994,1,1]]},"abstract":"<jats:p>Tetrahymena pyriformis was found to exhibit high NADPH-dependent 20-oxosteroid reductase activity that converted 17 alpha-hydroxyprogesterone into 17 alpha,20 alpha-dihydroxypregn-4-en-3-one. The enzyme was purified 400-fold from the cytosolic fraction. The purified enzyme with a specific activity of 6.4 mumol\/min per mg of protein had an isoelectric point of 4.9 and M(r) of 68,000, and was composed of two subunits of equal size. The N-terminal sequence was determined to be LAKTVPLNDGTNFPIFGG. The enzyme reduced pregnanes and pregnanes possessing a 17 alpha-hydroxy group to a greater extent than those without the hydroxy group, and oxidized 20 alpha-hydroxy groups of the steroids in the presence of NADP+. The Km values for 17 alpha-hydroxyprogesterone and 17 alpha-hydroxypregnenolone were 2.9 and 3.4 microM respectively. Although the enzyme was inactive towards androgens and oestrogens with 3- or 17-oxo groups, it reduced several nonsteroidal carbonyl compounds and oxidized trans-benzene dihydrodiol. The enzyme activity was inhibited by synthetic oestrogens, barbiturates, aldose reductase inhibitors and quercitrin. Thus, this enzyme is a novel form of 20 alpha-hydroxysteroid dehydrogenase (EC 1.1.1.149) which structurally and functionally differs from the mammalian and bacterial enzymes.<\/jats:p>","DOI":"10.1042\/bj2970195","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:36:00Z","timestamp":1439242560000},"page":"195-200","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Purification and characterization of a novel dimeric 20 <i>\u03b1<\/i>-hydroxysteroid dehydrogenase from <i>Tetrahymena pyriformis<\/i>"],"prefix":"10.1042","volume":"297","author":[{"given":"A","family":"Inazu","sequence":"first","affiliation":[{"name":"Biochemistry Laboratory, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Sato","sequence":"additional","affiliation":[{"name":"Biochemistry Laboratory, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T","family":"Nakayama","sequence":"additional","affiliation":[{"name":"Biochemistry Laboratory, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y","family":"Deyashiki","sequence":"additional","affiliation":[{"name":"Biochemistry Laboratory, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A","family":"Hara","sequence":"additional","affiliation":[{"name":"Biochemistry Laboratory, Gifu Pharmaceutical University, Mitahora-higashi, Gifu 502, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y","family":"Nozawa","sequence":"additional","affiliation":[{"name":"Deparment of Biochemistry, Gifu University School of Medicine, Tsukasamachi-40, Gifu 500, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/297\/1\/195\/612531\/bj2970195.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/297\/1\/195\/612531\/bj2970195.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T20:12:52Z","timestamp":1637698372000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/297\/1\/195\/30089\/Purification-and-characterization-of-a-novel"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,1,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1994,1,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2970195","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,1,1]]}}}