Human 3 beta-hydroxysteroid dehydrogenase/delta 5----4isomerase from placenta: expression in nonsteroidogenic cells of a protein that catalyzes the dehydrogenation/isomerization of C21 and C19 steroids.

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Lorence MC, Murry BA, Trant JM, Mason JI

Endocrinology. 1990 May;126(5):2493-8.

PubMed ID

2139411 [ View in PubMed

]

Abstract

The isolation, cloning, and expression of a cDNA insert complementary to mRNA encoding human 3 beta-hydroxysteroid dehydrogenase/delta 5----4isomerase is reported. The insert contains an open reading frame encoding a protein of 372 amino acids, the initial 29 amino acids corresponding to the N-terminal sequence identified from the purified human placental microsomal enzyme. The cDNA was inserted into a modified pCMV vector and expressed in COS-1 monkey kidney tumor cells. The expressed protein was similar in size to human placental microsomal 3 beta-hydroxysteroid dehydrogenase/delta 5----4isomerase, as detected by immunoblot analysis, and catalyzed the conversion of 17 alpha-hydroxypregnenolone to 17 alpha-hydroxyprogesterone, pregnenolone to progesterone, and dehydroepiandrosterone to androstenedione. Transfected COS cell homogenates, supplemented with NAD+, very efficiently oxidized 5 alpha-androstan-3 beta,17 beta-diol to 5 alpha-dihydrotestosterone and, upon addition of NADH, reduced 5 alpha-dihydrotestosterone to 5 alpha-androstan-3 beta,17 beta-diol. Thus, the dehydrogenation/isomerization steps of steroid biosynthesis can be catalyzed by a single polypeptide chain, which can metabolize all of the major physiological substrates.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Prasterone	3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 1	Protein	Humans	Unknown	Substrate	Details

Polypeptides

Name	UniProt ID
3 beta-hydroxysteroid dehydrogenase/Delta 5-->4-isomerase type 1	P14060	Details