Hydroxysteroid dehydrogenases and

Figure 2 Effect of enzyme immobilization on luminescent image spatial resolution evaluated using coupled enzymatic reactions on nylon net as a model system, (a) Immobilized 3a-hydroxysteroid dehydrogenase (b) immobilized 3a-hydroxysteroid dehydrogenase and FMN-NADH oxidoreductase (c) immobilized 3a-hydroxysteroid dehydrogenase, FMN-NADH oxidoreductase, and bacterial luciferase. (From Ref. 47. Copyright John Wiley Sons Ltd. Reproduced with permission.)...

Figure 2.2 Secretion of bile acids and biliary components. Bile acids (BA) cross the hepatocyte bound to 3a-hydroxysteroid dehydrogenase and are exported into the canaliculus by the bile-salt export protein (BSEP). Phosphatidylcholine (PC) from the inner leaflet of the apical membrane is flipped to the outer layer and interacts with bile acids secreted by BSEP. BA, PC, together with cholesterol from the membrane form mixed micelles that are not toxic to epithelial membranes of the biliary tree. Aquaporins (AQP) secrete water into bile.

Draper, N., Stewart, P. M. (2005) 11 f>-Hydroxysteroid dehydrogenase and the pre-receptor regulation of corticosteroid hormone action. J Endocrinol 186, 251-271. 

Krozowski Z. 11 (3-hydroxysteroid dehydrogenase and the short chain alcohol dehydrogenase (SCAD) superfamily. Mol Cell Endocrinol 84 1992 C25-C31. 

Kawasaki T, Maeda M, Tsuji A (1983) Immobilized -hydroxysteroid dehydrogenase and dansyl hydrazine as a pre-labeling reagent for high-performance liquid chromatography with fluorescence detection of bile acids. J Chromatogr 272 261-268... 

Rani K, Garg P, Pundir CS (2004) Measurement ofbileacidin serum and bile with arylamine-glass-bound -hydroxysteroid dehydrogenase and diaphorase. Anal Biochem 332 32-37... 

Trilostane blocks the synthetic path earlier (3p-hydroxysteroid dehydrogenase) and thus also inhibits aldosterone synthesis. 

II A5-3p-Hydroxysteroid dehydrogenase and A5-ketosteroid isom erase in 21-Hydroxylase IV Up-Hydroxylase... 

Wang, Y. and W. Ge. Cloning of zebrafish ovarian carbonyl reductase-like 20 beta-hydroxysteroid dehydrogenase and characterization of its spatial and temporal expression. Gen. Comp. Endocrinol. 127 209-216, 2002. 

C8. CavaUero, C., and Magrini, U., Histochemical studies on 3(S-hydroxysteroid-dehydrogenase and other enzymes in foetal steroid-secreting structures. Excerpta Med. Intern. Cmgr. Ser. Ill, 63-64 (1966). 

White PC, Mune T, Agarwal AK. 11 (3-Hydroxysteroid dehydrogenase and the syndrome of apparent mineralocorticoid excess. Endocr Rev 1997 18 135-156. 

Activation of the LH receptor results in an increase of intracellular cyclic adenosine monophosphate (cAMP) levels via activation of a G protein and adenylate cyclase. In the presence of elevated concentrations of cAMP, cholesterol esterase activation occurs. This enzyme catalyzes the cleavage of cholesterol esters to free cholesterol, v/hich is then converted in mitochondria to pregnenolone as described previously. The formation of progesterone from pregnenolone is catalyzed by 5-ene-3p-hydroxysteroid dehydrogenase and 3-oxosteroid-4,5-isomerase (steps c and d in Fig. 46.3). 

Testosterone is an intermediate in the biosynthesis of oestradiol. The conversion, which involves three successive hydroxylations and the loss of a methyl group, is catalysed by the enzyme aromatase. Aromatase has three catalytic activities 19-hydroxylase, 19-hydroxysteroid dehydrogenase and... 

Baker, M.E. (1995) Biochem. J., 309, 1029-1030, Enoyl-acyl-carrier-protein reductase and Mycobacterium tuberculosis InhA do not conserve the Tyr-Xaa-Xaa-Xaa-Lys motif in mammalian llp-and 1 P-hydroxysteroid dehydrogenases and Ehosoplula alcohol dehydrogenase. 

Four inborn errors of corticosteroid metabolism have been described deficiencies in hydroxysteroid dehydrogenase, and in 12-, 21-, or 11-hydroxylase [89, 90]. 

The next major step in the transformation of cholesterol to cholic acid is the conversion of the 5-choles-tene-3j8, 7a-diol into 7a-hydroxy-4-cholestene-3-one. Such conversion may occur through at least two different pathways. In the first, the substrate (5-choles-tene-3j8, 7a-diol) is sequentially attacked by a microsomal 3j8-hydroxysteroid dehydrogenase and then... 

Sato T et al (1999) Minoxidil increases 17 beta-hydroxysteroid dehydrogenase and 5 alpha-reductase activity of cultured human dermal papilla cells Irom balding scalp. J Dermatol Sci 19(2) 123-125... 

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