3β-Hydroxysteroid dehydrogenase/Δ5-4 isomerase (3β-HSD) (EC 1.1.1.145) is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone (DHEA) in the adrenal gland. It is the only enzyme in the adrenal pathway of corticosteroid synthesis that is not a member of the cytochrome P450 family.[1] It is also present in other steroid-producing tissues, including the ovary, testis and placenta. In humans, there are two 3β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes.
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Quick Facts hydroxy-Δ-5-steroid dehydrogenase,3β- and steroid Δ-isomerase 1, Identifiers ...
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3β-HSD is also known as delta Δ5-4-isomerase, which catalyzes the oxidative conversion of Δ5-3β-hydroxysteroids to the Δ4-3-keto configuration and is, therefore, essential for the biosynthesis of all classes of hormonal steroids, namely progesterone, glucocorticoids, mineralocorticoids, androgens, and estrogens.[2]
The 3β-HSD complex is responsible for the conversion of:
3β-HSD belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group with NAD+ or NADP+ as acceptor. This enzyme participates in C21-steroid hormone metabolism and androgen and estrogen metabolism.
3β-HSD catalysis|catalyzes the chemical reaction:
- a 3β-hydroxy-Δ5-steroid + NAD+ ⇌ a 3-oxo-Δ5-steroid + NADH + H+
Thus, the two substrates of this enzyme are 3β-hydroxy-Δ5-steroid and NAD+, whereas its three products are 3-oxo-Δ5-steroid, NADH, and H+.
Humans express two 3β-HSD isozymes, HSD3B1 (type I) and HSD3B2 (type II).[3] The type I isoenzyme is expressed in placenta and peripheral tissues, whereas the type II 3β-HSD isoenzyme is expressed in the adrenal gland, ovary, and testis.
The systematic name of this enzyme class is 3β-hydroxy-Δ5-steroid:NAD+ 3-oxidoreductase. Other names in common use include:
- progesterone reductase
- Δ5-3β-hydroxysteroid dehydrogenase
- 3β-hydroxy-5-ene steroid dehydrogenase
- 3β-hydroxy steroid dehydrogenase/isomerase
- 3β-hydroxy-Δ5-C27-steroid dehydrogenase/isomerase
- 3β-hydroxy-Δ5-C27-steroid oxidoreductase
- 3β-hydroxy-5-ene-steroid oxidoreductase
- steroid-Δ5-3β-ol dehydrogenase
- 3β-HSDH
- 5-ene-3β-hydroxysteroid dehydrogenase
- 3β-hydroxy-5-ene-steroid dehydrogenase
Cravioto MD, Ulloa-Aguirre A, Bermudez JA, Herrera J, Lisker R, Mendez JP, Perez-Palacios G (August 1986). "A new inherited variant of the 3 beta-hydroxysteroid dehydrogenase-isomerase deficiency syndrome: evidence for the existence of two isoenzymes". J. Clin. Endocrinol. Metab. 63 (2): 360–7. doi:10.1210/jcem-63-2-360. PMID 3088022. Cooke GM (April 1996). "Differential effects of trilostane and cyanoketone on the 3 beta-hydroxysteroid dehydrogenase-isomerase reactions in androgen and 16-androstene biosynthetic pathways in the pig testis". J. Steroid Biochem. Mol. Biol. 58 (1): 95–101. doi:10.1016/0960-0760(96)00002-7. PMID 8809191. S2CID 23048546. Rhéaume E, Simard J, Morel Y, Mebarki F, Zachmann M, Forest MG, New MI, Labrie F (July 1992). "Congenital adrenal hyperplasia due to point mutations in the type II 3 beta-hydroxysteroid dehydrogenase gene". Nat. Genet. 1 (4): 239–45. doi:10.1038/ng0792-239. PMID 1363812. S2CID 26468595.
- Cheatum SG, Watten JC (1966). "Purification and properties of 3-beta-hydroxysteroid dehydrogenase and delta-5-3-ketosteroid isomerase from bovine corpora lutea". Biochim. Biophys. Acta. 122 (1): 1–13. doi:10.1016/0926-6593(66)90086-5. PMID 4226148.
- Koritz SB (1964). "The conversion of prepnenolone to progesterone by small particle from rat adrenal". Biochemistry. 3 (8): 1098–1102. doi:10.1021/bi00896a015. PMID 14220672.
- Neville AM, Orr JC, Engel LL (1968). "Delta5-3beta-Hydroxy steroid dehydrogenase activities of bovine adrenal cortex". Biochem. J. 107: 20.