Add time:08/24/2019         Source:sciencedirect.com

Several studies have shown that the native 7α-hydroxy-dehydroepiandrosterone (7α-hydroxy-DHEA) is a substrate for the human 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which converts the 7α- into the 7β-epimer through an oxido-reduction process. Research on the 11β-HSD1 has investigated its function and structure through using native glucocorticoid substrates and known inhibitors. Other steroid substrates are also of interest. Among testosterone metabolites, 5α-androstane-3β,17β-diol (Adiol) is a substrate for the cytochrome P450 7B1 which produces 5α-androstane-3β,7α,17β-triol (7α-Adiol). This steroid may be a substrate for the 11β-HSD1. We used recombinant yeast-expressed 11β-HSD1 with NADP(H)-regenerating systems for examining the products obtained after incubation with 7α-Adiol, 7β-Adiol or 7-oxo-Adiol. Oxidative conditions for the 11β-HSD1 provided no trace of 7-oxo-Adiol but the inter-conversion of 7α- and 7β-hydroxy-Adiol with Vmax/KM (pmol min−1 μg−1/μM) values of 2 and 0.5, respectively. This state was maintained under reductive conditions. The use of a 7-oxo-Adiol substrate under reductive conditions led to the production of both 7α- and 7β-hydroxy-Adiol with Vmax/KM values of 3.43 and 0.22, respectively. These findings support the hypothesis that the oxido-reductase and epimerase activities of 11β-HSD1 depend on the positioning of the steroid substrates within the active site and may provide insight into its fine structure and mechanism of action.

We also recommend Trading Suppliers and Manufacturers of (7α,17β)-3-Methoxy-7-Methyl-estra-1,3,5(10)-trien-17-ol (cas 15506-01-1). Pls Click Website Link as below: cas 15506-01-1 suppliers