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) |
|---|---|
| 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 |
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ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology
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An active-site-directed irreversible inhibitor of Δ5-3-ketosteroid isomerase. / Pollack, Ralph M.; Kayser, Robert H.; Bevins, Charles L.
In: Biochemical and Biophysical Research Communications, Vol. 91, No. 3, 14.12.1979, p. 783-790.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An active-site-directed irreversible inhibitor of Δ5-3-ketosteroid isomerase
AU - Pollack, Ralph M.
AU - Kayser, Robert H.
AU - Bevins, Charles L
PY - 1979/12/14
Y1 - 1979/12/14
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0018638113&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0018638113&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(79)91948-X
DO - 10.1016/0006-291X(79)91948-X
M3 - Article
C2 - 526282
AN - SCOPUS:0018638113
VL - 91
SP - 783
EP - 790
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -