5β-Reductase
5β-Reductase, or Δ4-3-oxosteroid 5β-reductase is an enzyme with systematic name 5β-cholestan-3-one:NADP+ 4,5-oxidoreductase. This enzyme catalyses the following chemical reaction
The human enzyme efficiently acts on progesterone, 17α-hydroxyprogesterone, androstenedione, and testosterone to 5β-reduced metabolites. It can also act on aldosterone, corticosterone and cortisol, to some extent.
