Abstract
The α and β isomers of spiro-3-oxiranyl-5α-androstan-17β-ol were tested as possible inhibitors of Δ5-3-ketosteroid isomerase of Pseudomonas testosteroni. The β-oxirane causes a first-order irreversible inactivation of the enzyme and shows saturation kinetics (KI, 17 μM). Protection against inactivation is exhibited by 19-nortestosterone, a competitive inhibitor of the isomerase. Although the α-oxirane was found to be a good reversible inhibitor (Ki, 21 μM), prolonged incubation with it failed to produce any inactivation of the isomerase. The results obtained are consistent with the presence of a nucleophilic group situated near the 3-keto group of the substrate in the enzyme-steroid complex.
Original language | English (US) |
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Pages (from-to) | 783-790 |
Number of pages | 8 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 91 |
Issue number | 3 |
DOIs | |
State | Published - Dec 14 1979 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology