| 1 | Author
| HildegardM. Aria, W. Arneck, H. Anns, Ulrich Seitz | Requires cookie* | | Title
| 3 ß-Hydroxysteroid Oxidoreductase in Suspension Cultures of Digitalis lanata EH RH  | | | Abstract
| A 3 ß-hydroxysteroid oxidoreductase was isolated and characterized in the m icrosomes o f Digitalis lanata cell cultures. The enzyme catalyzes the conversion o f 5a-pregnane-3,20-dione to 5a-pregnan-3 ß-ol-20-one and requires N A D (P)H 2. The enzyme was found to have a pH optimum o f 8.0. The reaction had an optimum incubation temperature o f 25 °C with linear reduction for the first 4 h, reaching maximum enzyme activity after 7 h. Substrate kinetics for 5a-pregnane-3,20-dione and N A D P H 2 resulted in apparent A^-values o f 1 8 .5 -2 0 (iM for 5a-pregnane-3,20-dione and 5 0 -1 2 0 |iM for the co-substrate N A D P H ,. In order to localize 3 ß-hydroxysteroid oxidoreductase differential centrifugation as well as linear sucrose density gradient centrifugation were performed. The results obtained lead to the conclusion that 3 ß-hydroxysteroid oxidoreductase is not associated with a single cell compartment, but con sists o f a major soluble part and a markedly smaller part o f endoplasmic reticulum-associated activity. | | |
Reference
| Z. Naturforsch. 45c, 963 (1990); received July 16. 1990 | | |
Published
| 1990 | | |
Keywords
| Cell Cultures, Digitalis lanata, 3 ß-Hydroxysteroid Oxidoreductase, Steroids | | |
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| default:Reihe_C/45/ZNC-1990-45c-0963.pdf | | | Identifier
| ZNC-1990-45c-0963 | | | Volume
| 45 | |
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