Steroidogenic enzyme

Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis.^[2]^[3]^[4]^[5] They are responsible for the biosynthesis of the steroid hormones, including sex steroids (androgens, estrogens, and progestogens) and corticosteroids (glucocorticoids and mineralocorticoids), as well as neurosteroids, from cholesterol.^[3]^[4]^[5] Steroidogenic enzymes are most highly expressed in classical steroidogenic tissues, such as the testis, ovary, and adrenal cortex, but are also present in other tissues in the body.^[3]^[4]^[5]

List of steroidogenic enzymes

Steroid desmolases
- Cholesterol side-chain cleavage enzyme (20,22-desmolase) – steroid synthesis
- 17,20-Lyase (17,20-desmolase) – androgen synthesis
Steroid hydroxylases
- 11β-Hydroxylase – corticosteroid synthesis
- 17α-Hydroxylase – androgen and glucocorticoid synthesis
- 18-Hydroxylase (aldosterone synthase) – mineralocorticoid synthesis
- 21-Hydroxylase – corticosteroid synthesis
- Cytochrome P450 (CYP1, 2, 3) – estrogen metabolism
Hydroxysteroid dehydrogenases (and ketosteroid reductases)
- 3α-Hydroxysteroid dehydrogenase – androgen, progestogen, and neurosteroid synthesis and metabolism
- 3β-Hydroxysteroid dehydrogenase/Δ^5-4-isomerase (1, 2) – androgen, progestogen, and neurosteroid synthesis
- 11β-Hydroxysteroid dehydrogenase (1, 2) – corticosteroid synthesis and metabolism
- 17β-Hydroxysteroid dehydrogenase (1–15) – androgen, estrogen, and progestogen synthesis and metabolism
- 20α-Hydroxysteroid dehydrogenase – progestogen synthesis and metabolism
- 20β-Hydroxysteroid dehydrogenase – progestogen synthesis and metabolism

Steroid reductases
- 5α-Reductase (1, 2, 3) – androgen and neurosteroid synthesis, progestogen metabolism
- 5β-Reductase – androgen and progestogen metabolism, neurosteroid synthesis
Conjugation (and deconjugation)
- Glucuronosyltransferase (UGT2Bs) – steroid metabolism^[6]
- Glucuronidase (β-glucuronidase) – steroid synthesis^[7]
- Steroid sulfotransferase (SULT1A1, 1E1, 2A1, 2B1a, 2B1b) – steroid metabolism, neurosteroid synthesis^[8]
- Steroid sulfatase – steroid synthesis, neurosteroid metabolism^[8]
Others
- Aromatase (estrogen synthetase) – estrogen synthesis