Hydroxy steroid dehydrogenase

Trichloroethylene 1.9 OS-phosphate buffer pH 7 (2/1) 20 /S-Hydroxy steroid dehydrogenase... 

Figure 6d shows the modeled a helix F interface in pig 17 P-hydroxy steroid dehydrogenase type 4. Leucine-169 is 2.9 A from glycine-173. Leucine-174 is 4.3 A from alanine-162 and 3.3 A from alanine-166. There also is a hydrogen bond between serine-165 and serine-175, which are 3 A apart. 

Enzyme defect Mevalonate kinase 3/ -Hydroxy-steroid dehydrogenase 3/M Iydroxy-sterol 8- 7-isomerase 3/I-Hydroxysterol 14-reductase 3/1-1 Iydroxysterol A5-dcsaturasc 3/ -Hydroxysterol 24-reductase 3/l-Hydroxysterol 7-reductase... 

Some of the effects of glucocorticoids can be attributed to their binding to aldosterone receptors (AR). Indeed, ARs bind aldosterone and cortisol with similar affinity. A mineralocorticoid effect of cortisol is avoided in some tissues by expression of 11 B-hydroxy steroid dehydrogenase type 2, the enzyme responsible for biotransformation to its 11-keto derivative (cortisone), which has minimal affinity for aldosterone receptors. 

Trilostane is a 3 B-17 hydroxy steroid dehydrogenase inhibitor that interferes with the synthesis of adrenal and gonadal hormones and is comparable to aminoglutethimide. Its side effects are predominantly gastrointestinal adverse effects occur in about 50% of patients with both agents. There is no cross-resistance or crossover of side effects between these compounds. 

M (decreased testicular protein, 3 beta-hydroxy steroid dehydrogenase and serum testosterone)... 

Fig. 6. Biosynthetic pathways for corticosteroids. (TT) indicates position of hydroxylation HSD, hydroxy-steroid dehydrogenase.

A single 3/8-hydroxy-steroid dehydrogenase A5-3-oxo-steroid isomerase complex is present in human adrenal301 but a similar complex isolated from rat mitochondria was thought to be a redistribution artefact.302 The dimeric form of the A5-3-oxo-steroid isomerase from Pseudomonas species has a molecular weight of 26 800 dalton and is unusually stable to dissociation on dilution 303 it may be the catalytically active species. The enzyme from a bacterial source is irreversibly inhibited by an acetylenic analogue of the natural substrate.304... 

Figure 23-5 Outline of the biosynthesis of steroid hor-"TOnes. 3fi-HSD, 3/S-hydroxy-steroid dehydrogenase/J " Mmerase 17fi-HSD, 17/S-hy-dioxysteroid dehydrogenase.

Hydroxy-steroid dehydrogenases co-immobilized on Sepharose 4B with NADH FMN oxidoreductase and luciferase provide light-emission assays for picomole levels of androsterone or testosterone.145... 

B28. Bongiovanni, A. M., The adrenogenital syndrome with deficiency of 3/3-hydroxy-steroid dehydrogenase. J. Clin. Invest. 41, 2086-2092 (1962). 

Another anti-cancer mechanism of isoflavones may involve inhibition of key enzymes of estrogen metabolism, such as 3 p-hydroxy steroid dehydrogenase, 17P-hydroxysteroid dehydrogenase, 5a-reductase and aromatase, as a consequence of which the level of active steroid hormones is affected [81, 106, 107],... 

Fig. 44.22. Biosynthesis of the adrenocorticoids from cholesterol. The enzymes involved are (a) side chain cleavage, b) 17a-hydroxylase, (c) 5-ene-3p-hydroxy-steroid dehydrogenase, (cf) 3-oxosteroid-4,5-isomerase, (e) 21-hydroxylase, (f) 11 p-hydroxylase, and (g)...

Hundertmark, S., A. Dill, H. Buhler, et al. 2002. llbeta-Hydroxy-steroid dehydrogenase type 1 A new regulator of fetal lung maturation. Horm. Metab. Res. 34(10) 537-544. 

Stewart, P.M., A.M. Wallace, R. Valentino, et al. 1987. Mineralocorticoid activity of liquorice 11-beta-hydroxy steroid dehydrogenase deficiency comes of age. Lancet 2(8563) 821-824. 

Oppermann, U.C., Filling, C., Bemdt, K.D., Persson, B., Benach, J., Ladenstein, R. Jornvall, H. (1997) Biochmistry 36, 34-40. Active site directed mutagenesis of 3 beta/17 beta-hydroxy-steroid dehydrogenase establishes differential effects on short-chain dehydrogenase/reductase reactions. 

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