17-n-n-diethylcarbamoyl-4-methyl-4-azaandrostane-3-one has been researched along with 5-androstene-3-17-dione* in 1 studies
1 other study(ies) available for 17-n-n-diethylcarbamoyl-4-methyl-4-azaandrostane-3-one and 5-androstene-3-17-dione
| Article | Year |
|---|---|
Differential inhibition of dehydrogenase and 5-ene----4-ene isomerase activities of purified 3 beta-hydroxysteroid dehydrogenase. Evidence for two distinct sites.
The success in synthesis of [3H]5-androstene-3,17-dione, the intermediate product in the transformation of DHEA to 4-androstenedione by 3 beta-hydroxysteroid dehydrogenase/5-ene----4-ene isomerase (3 beta-HSD) offers the opportunity to determine whether or not the two activities reside in one active site or in two closely related active sites. The finding that N,N-dimethyl-4-methyl-3-oxo-4-aza-5 alpha-androstane-17 beta-carboxamide (4-MA) inhibits competitively and specifically the dehydrogenase activity whereas a non-competitive inhibition type with a Ki value 1000 fold higher was observed for the isomerase activity, indicated that dehydrogenase and isomerase activities belong to separate sites. Using 5 alpha-dihydro-testosterone and 5 alpha-androstane-3 beta, 17 beta-diol, exclusive substrates for dehydrogenase activity, it was shown that dehydrogenase is reversible and strongly inhibited by 4-MA and that thus the irreversible step in the transformation of DHEA to 4-androstenedione is due to the isomerase activity. Topics: 3-Hydroxysteroid Dehydrogenases; Androstenedione; Azasteroids; Binding Sites; Dehydroepiandrosterone; Dihydrotestosterone; Humans; In Vitro Techniques; Kinetics | 1991 |