Showing papers on "Hydroxysteroid dehydrogenase published in 1992"
TL;DR: The nucleotide sequence of the two highly homologous genes encoding 3β–HSD isoenzymes in three classic 3β-HSD deficient patients belonging to two apparently unrelated pedigrees is described, providing the first elucidation of the molecular basis of this disorder.
Abstract: Classical 3β–hydroxysteroid dehydrogenase /Δ5–Δ4–isomerase (3β–HSD) deficiency is an autosomal recessive form of congenital adrenal hyperplasia characterized by a severe impairment of steroid biosynthesis in both the adrenals and the gonads We describe the nucleotide sequence of the two highly homologous genes encoding 3β–HSD isoenzymes in three classic 3β–HSD deficient patients belonging to two apparently unrelated pedigrees No mutation was detected in the type I 3β–HSD gene, which is mainly expressed in the placenta and peripheral tissues Both nonsense and frameshift mutations, however, were found in the type II 3β–HSD gene, which is the predominant 3β–HSD gene expressed in the adrenals and gonads, thus providing the first elucidation of the molecular basis of this disorder
213 citations
TL;DR: The present data suggest the existence of two 17β-HSDs, which efficiently catalyzes the interconversion of estrone and estradiol while dehydroepiandrosterone and 5-androstene-3β,17β-diol are interconverted at a lower rate.
66 citations
TL;DR: Two monomeric dihydrodiol dehydrogenases with pI values of 5.4 and 7.6 were co-purified with androsterone dehydrogenase activity to homogeneity from human liver.
Abstract: Two monomeric dihydrodiol dehydrogenases with pI values of 5.4 and 7.6 were co-purified with androsterone dehydrogenase activity to homogeneity from human liver. The two enzymes differed from each other on peptide mapping and in their heat-stabilities; with respect to the latter the dihydrodiol dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase activities of the respective enzymes were similarly inactivated. The pI 5.4 enzyme was equally active towards trans- and cis-benzene dihydrodiols, and towards (S)- and (R)-forms of indan-1-ol and 1,2,3,4-tetrahydronaphth-1-ol and oxidized the 3 alpha-hydroxy group of C19-, C21- and C24-steroids, whereas the pI 7.6 enzyme showed high specificity for trans-benzene dihydrodiol, (S)-forms of the alicyclic alcohols and C19- and C21-steroids. Although the two enzymes reduced various xenobiotic carbonyl compounds and the 3-oxo group of C19- and C21-steroids, and were A-specific in the hydrogen transfer from NADPH, only the pI 5.4 enzyme showed reductase activity towards 7 alpha-hydroxy-5 beta-cholestan-3-one and dehydrolithocholic acid. The affinity of the two enzymes for the steroidal substrates was higher than that for the xenobiotic substrates. The two enzymes also showed different susceptibilities to the inhibition by anti-inflammatory drugs and bile acids. Whereas the pI-5.4 enzyme was highly sensitive to anti-inflammatory steroids, showing mixed-type inhibitions with respect to indan-1-ol and androsterone, the pI 7.6 enzyme was inhibited more potently by non-steroidal anti-inflammatory drugs and bile acids than by the steroidal drugs, and the inhibitions were all competitive. These structural and functional differences suggest that the two enzymes are 3 alpha-hydroxysteroid dehydrogenase isoenzymes.
57 citations
TL;DR: The results suggest the presence of limited regions especially sensitive to proteolysis and the possibility of some association between the enzyme active site and the sensitive site(s).
Abstract: Prokaryotic 3 alpha/20 beta-hydroxysteroid dehydrogenase exhibits one segment sensitive to proteolysis with Glu-C protease and trypsin (cleaving after Glu192 and Arg196, respectively). Cleavage is associated with dehydrogenase inactivation; the presence of NADH offers almost complete protection and substrate (cortisone) gives some protection. Distantly related insect alcohol dehydrogenase is more resistant to proteolysis, but cleavage in a corresponding segment is detectable with Asp-N protease (cleaving before Asp198), while a second site (at Glu243) is sensitive to cleavage with both Glu-C and Asp-N proteases. Combined, the results suggest the presence of limited regions especially sensitive to proteolysis and the possibility of some association between the enzyme active site and the sensitive site(s). Modification of the hydroxysteroid dehydrogenase with tetranitromethane is paralleled by enzyme inactivation. With a 10-fold excess of reagent, labeling corresponds to 1.2 nmol Tyr/nmol protein chain and is recovered largely in Tyr152, with lesser amounts in Tyr251. Tetranitromethane also rapidly inhibits the other two dehydrogenases, but they contain Cys residues, preventing direct correlation with Tyr modification. Together, the proteolysis and chemical modifications highlight three segments of short-chain dehydrogenase subunits, one mid-chain, containing Tyr152 of the steroid dehydrogenase (similar numbers in the other enzymes), strictly conserved and apparently close to the enzyme active site, the other around position 195, sensitive to proteolysis and affected by coenzyme binding, while the third is close to the C-terminus.
52 citations
TL;DR: Streptomyces hydrogenans 3α, 20β-hydroxysteroid dehydrogenase reduces the C20 ketone on glucocorticoids and progestins is inhibited by glycyrrhizic acid and carbenoxolone, indicating that these compounds are binding at or close to the catalytic site.
26 citations
TL;DR: Based on the molecular weights and the co‐substrate specificities microsomal mouse liver MPON reductase and Pseudomonas 3α‐HSD seem to be members of the short‐chain alcohol dehydrogenase family.
25 citations
TL;DR: In this paper, two representatives of different fungal taxonomic classes were tested for constitutive 17β-hydroxysteroid dehydrogenase (HSDH) activity and the results were positive in all cases.
Abstract: Two representatives of each of different fungal taxonomic classes were tested for constitutive 17β-hydroxysteroid dehydrogenase (HSDH) activity and the results were positive in all cases. The enzyme was found to be regioselective for C17 of the steroid ring and 20β-HSDH activity was only detected in Trichoderma viride. In most cases the oxidative pathway is favoured over the reductive pathway. The possible role of this enzyme in fungi is discussed.
20 citations
TL;DR: The present data demonstrate the multifunctional enzymatic activities associated with a recombinant oxidoreductase enzyme, in addition to its well known 3β-HSD activity, this enzyme possesses the ability to catalyze DHT into A-dione thus potentially controlling the level of the active androgen DHT in classical steroidogenic as well as peripheral intracrine tissues.
Abstract: Transient expression in nonsteroidogenic mammalian cells of the rat wild type I and type II 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase (3β- HSD) cDNAs shows that the encoded proteins, in addition to being able to catalyze the oxidation and isomerization of Δ5-3β-hydroxysteroid precursors into the corresponding Δ4-3-ketosteroids, interconvert 5α- dihydrotestosterone (DHT) and 5α-androstane-3β,17β-diol (3β-diol). When homogenate from cells transfected with a plasmid vector containing type I 3β-HSD is incubated in the presence of DHT using NAD+ as cofactor, a somewhat unexpected metabolite is formed, namely 5α-androstanedione (A- dione), thus indicating an intrinsic androgenic 17β-hydroxysteroid dehydrogenase (17β-HSD) activity of this 3β-HSD isoform. Although the relative Vmax of 17β-HSD activity is 14.9-fold lower than that of 3β-HSD activity, the Km value for the 17β-HSD activity of type I 3β-HSD is 7.97 μM, a value which is in the same range as the conversion of DHT into 3β- diol which shows a Km value of 4.02 μM. Interestingly, this 17β-HSD activity is highly predominant in unbroken cells in culture, thus supporting the physiological relevance of this 'secondary' activity. Such 17β-HSD activity is inhibited by the classical substrates of 3β-HSD, namely pregnenolone (PREG), dehydroepiandrosterone (DHEA), Δ5-androstene-3β,17β- diol (Δ5-diol), 5α-androstane-3β,17β-diol (3β-diol) and DHT, with IC50 values of 2.7, 1.0, 3.2, 6.2, and 6.3 μM, respectively. Although dual enzymatic activities have been previously reported for purified preparations of other steroidogenic enzymes, the present data demonstrate the multifunctional enzymatic activities associated with a recombinant oxidoreductase enzyme. In addition to its well known 3β-HSD activity, this enzyme possesses the ability to catalyze DHT into A-dione thus potentially controlling the level of the active androgen DHT in classical steroidogenic as well as peripheral intracrine tissues.
18 citations
TL;DR: It is reported here that neonatal pig testis is rich in 3α/β- and 20β-hydroxysteroid dehydrogenase activities, both of which fall to low levels (measured as specific activity) at 60 days, and proposed that the neonatal testis possesses the bifunctional enzyme which is replaced by a second enzyme at maturity.
15 citations
01 Jan 1992
TL;DR: Three enzyme forms of carbonyl reductase were purified from chicken liver with using 4-benzoylpyridine as a substrate and the results suggest that CR1 is a hydroxysteroid dehydrogenase, and CR2 and CR3 are similar to each other and to the kidney enzymes.
Abstract: Three enzyme forms (CR1, CR2 and CR3) of carbonyl reductase were purified from chicken liver with using 4-benzoylpyridine as a substrate. CR1 was a dimeric enzyme composed of two identical 25-kD subunits. CR2 and CR3 were monomeric enzymes whose molecular weights were both 32 kD. CR1 exhibited 17 beta-hydroxysteroid dehydrogenase activity as well as carbonyl reductase activity in the presence of both NADP(H) and NAD(H). CR2 and CR3 had similar properties with regard to substrate specificity and inhibitor sensitivity. They could exhibit the activity only with NADPH and had no hydroxysteroid dehydrogenase activity. CR2 and CR3 cross-reacted with anti-chicken kidney carbonyl reductase antibody, though CR1 did not. The results suggest that CR1 is a hydroxysteroid dehydrogenase, and CR2 and CR3 are similar to each other and to the kidney enzymes.
13 citations
TL;DR: The albumin present in breast tumor cytosol may be a contributing factor to the observed stimulation of reductive E2DH activity in cultured MCF-7 breast cancer cells.
Patent•
02 Jun 1992TL;DR: In this article, 1-(4'-nitrophenyl)-2-propen-1-ol and 2-proben-2-ol were shown to be highly selective non-steroidal suicide substrates for rat liver 3 alpha -hydroxysteroid dehydrogenase.
Abstract: Compounds, such as 1-(4'-nitrophenyl)-2-propen-1-ol, are disclosed which are highly selective non-steroidal suicide substrates for rat liver 3 alpha -hydroxysteroid dehydrogenase.
30 Jun 1992
TL;DR: The initial velocity and product inhibition studies indicated that the enzyme reaction sequence is ordered with NADP+ binding to the free enzyme and NADPH being the last product to be released.
TL;DR: Studies of Michaelis constants of 20-alpha-HSD indicate that this monoclonal antibody increases the Km for 20- alpha-dihydroprogesterone and decreases the Vmax.
TL;DR: It is suggested that delayed involution of the fetal adrenal cortex was the cause of the abnormal test results in these two patients, which demonstrated a normal response of precursor adrenal steroids to ACTH stimulation.
Abstract: We report two infants who had elevated blood levels of the Δ adrenal steroids 17-hydroxypregnenolone and DHEA suggestive of congenital adrenal hyperplasia due to non-salt-losing 3/3-hydroxysteroid dehydrogenase deficiency. One of the infants was a male with perineal hypospadias and the other a female with an increased level of 17-hydroxyprogesterone on a neonatal screen for congenital adrenal hyperplasia. Retesting some months later demonstrated a normal response of precursor adrenal steroids to ACTH stimulation. We suggest that delayed involution of the fetal adrenal cortex was the cause of the abnormal test results in these two patients.