20α-hydroxysteroid dehydrogenase activity a function of human placental 17β-hydroxysteroid dehydrogenase

Purdy, Robert H.; Halla, Märta; Little, Brian

doi:10.1016/0926-6569(64)90087-2

Cited by 20 publications

(7 citation statements)

References 6 publications

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“…The second aim of these investigations was to test the hypothesis that 170-estradiol dehydrogenase and 20a-hydroxysteroid dehydrogenase activities in human term placental cytosol represent bifunctional enzyme activity on one protein. This hypothesis was first stated by Purdy et al (1964) and is supported by our observations that these activities copurify (Strickler & Tobias, 1980) and are identically inactivated by the affinity alkylating steroid 16a-bromoacetoxyprogesterone (Strickler et al, 1981). In these studies, both the 170-estradiol dehydrogenase and 20a-hydroxysteroid dehydrogenase activities were simultaneously and identically inactivated by several concentrations of FSA in buffers of different pH.…”

Section: Discussionsupporting

confidence: 73%

Affinity labeling of human placental 17.beta.-estradiol dehydrogenase and 20.alpha.-hydroxysteroid dehydrogenase with 5'-[p-(fluorosulfonyl)benzoyl]adenosine

Tobias¹,

Strickler²

1981

Biochemistry

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Two pyridine nucleotide linked oxidoreductase activities, 17 beta-estradiol dehydrogenase and 20 alpha-hydroxysteroid dehydrogenase, which were copurified from human placental cytosol as a homogeneous enzyme preparation, may represent dual activity by one enzyme. The affinity labeling nucleotide analogue 5'-[p-(fluorosulfonyl)benzoyl]adenosine, which binds at the cofactor site as a competitive inhibitor of NADH (ki = 1.7 mM), simultaneously and identically inactivated both the 17 beta and 20 alpha activities in a time-dependent and irreversible manner following pseudo-first-order kinetics. NADH and NAD+ markedly protected both activities from inactivation, and the substrate steroids, estrone, estradiol, progesterone, and 20 alpha-hydroxy-4-pregnen-3-one, conferred similar protection, though less than cofactor, against simultaneous loss of both activities. Stoichiometric studies indicated that 2 mol of affinity labeling nucleotide were bound per mol of completely inactivated enzyme dimer. The coincident and identical loss of both activities under all experimental conditions is further evidence that 17 beta-estradiol dehydrogenase and 20 alpha-hydrosteroid dehydrogenase in human placental cytosol represent bifunctional, stereospecific, oxidoreductase activity at one active site on a single protein.

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Section: Discussionsupporting

confidence: 73%

Affinity labeling of human placental 17.beta.-estradiol dehydrogenase and 20.alpha.-hydroxysteroid dehydrogenase with 5'-[p-(fluorosulfonyl)benzoyl]adenosine

Tobias¹,

Strickler²

1981

Biochemistry

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“…This is not to say that estradiol 17/3dehydrogenase will not catalyze 20a-oxidoreduction of progesterone. Indeed, the work of both Strickler (Strickler et al, 1991) and Purdy (Purdy et al, 1964) clearly demonstrates that the enzyme performs that catalysis. What is indicated, however, is that there are other enzyme(s) capable of effecting 20a-oxidoreduction of steroids.…”

Section: Discussionmentioning

confidence: 99%

Molecular cloning of testicular 20.alpha.-hydroxysteroid dehydrogenase: Identity with aldose reductase

Warren¹,

Murdock²,

Ma³

et al. 1993

Biochemistry

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Complementary DNA (cDNA) clones encoding bovine testicular 20 alpha-hydroxysteroid dehydrogenase (20 alpha-HSD) have been isolated from a bovine testicular lambda gt11 library using polyclonal antibodies against 20 alpha-HSD and DNA probe hybridization. Nucleotide sequencing of three independently isolated clones was used to establish a composite cDNA sequence that encodes the enzyme. It contains a coding sequence of 921 nucleotides, a stop codon, and a 264-nucleotide 3'-noncoding segment which allowed deduction of the amino acid sequence of the enzyme. A computer homology search of the 20 alpha-HSD cDNA performed against the GenBank DNA sequence database revealed it to be identical with bovine lens aldose reductase (alditol:NADPH oxidoreductase; EC 1.1.1.21), and a literature search reveals the deduced amino acid sequence to be identical with that reported for the bovine enzyme. Sequences obtained from the N-terminus of purified testicular 20 alpha-HSD and from random peptides obtained by treatment with endopeptidase Lys-C are all identical with regions of the deduced amino acid sequence of 20 alpha-HSD and/or the published sequence of aldose reductase. Further, the enzyme purified to homogeneity by following activity with 17-hydroxyprogesterone as a substrate was shown to reduce glucose, glyceraldehyde, and benzaldehyde (all classic aldose reductase substrates). Finally, 17-hydroxyprogesterone inhibited the reduction of benzaldehyde and glyceraldehyde. Because aldose reductase has been implicated in the etiology of diabetic complications, acceptance of steroid substrates may offer new implications for therapy.

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“…It is therefore of interest that 20a-hydroxypregn-4-en-3-one was formed from progesterone and pregnenolone by isolated granulosa cells in the present study, regardless of whether the ovaries contained corpora lutea or not. The combined occurrence of 20a-hydroxysteroid dehydrogenase and of a high 17/5-hydroxysteroid dehydrogenase activity has further interest in view of the findings of Purdy, Halla & Little (1964) that highly purified preparations of a soluble 17/5-hydroxysteroid dehydrogenase from human placenta tissue possess low 20a-hydroxysteroid dehydrogenase activity. Recently Davenport & Mallette (1966) reported both 20aand 17/5-hydroxysteroid dehydrogenase activities in the soluble fraction of rabbit ovarian homogenate.…”

Section: Lars Bjersing and Hans Carstensenmentioning

confidence: 99%

Biosynthesis of Steroids by Granulosa Cells of the Porcine Ovary in Vitro

Bjersing¹,

Carstensen²

1967

Reproduction

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Incubation of granulosa cell aggregates from porcine ovarian follicles with progesterone-4-1 4C, 17\g=a\-hydroxyprogesterone-4\x=req-\ 14C, pregnenolone-7\g=a\-3H, testosterone-4-1 4C and androstene-3,17dione-4-14C showed that they contained efficient 3\g=b\-hydroxysteroid dehydrogenase, 20\g=a\-hydroxysteroiddehydrogenase and 17\g=b\-hydroxysteroid dehydrogenase enzyme activities. There were also some aromatizing and probably some 21-hydroxylating enzyme activities. The granulosa cells were particularly low in 17\g=a\-hydroxylase and sidechain cleaving enzyme activities although some activity was demonstrated.

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20α-hydroxysteroid dehydrogenase activity a function of human placental 17β-hydroxysteroid dehydrogenase

Cited by 20 publications

References 6 publications

Affinity labeling of human placental 17.beta.-estradiol dehydrogenase and 20.alpha.-hydroxysteroid dehydrogenase with 5'-[p-(fluorosulfonyl)benzoyl]adenosine

Affinity labeling of human placental 17.beta.-estradiol dehydrogenase and 20.alpha.-hydroxysteroid dehydrogenase with 5'-[p-(fluorosulfonyl)benzoyl]adenosine

Molecular cloning of testicular 20.alpha.-hydroxysteroid dehydrogenase: Identity with aldose reductase

Biosynthesis of Steroids by Granulosa Cells of the Porcine Ovary in Vitro

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