出典:Wikipedia
出典:『Wikipedia』 (2011/08/03 06:43 UTC 版)
3-β-HSD (or 3-β-hydroxysteroid dehydrogenase/Δ-5-4 isomerase) is an enzyme that catalyses the synthesis of progesterone from pregnenolone, 17-hydroxyprogesterone from 17-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone 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. In humans, there are two 3-β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes, respectively.