Reaction: 5α-cholestan-3-one + NADP+ = cholest-4-en-3-one + NADPH + H+
Other name(s): testosterone Δ4-5α-reductase; steroid 5α-reductase; 3-oxosteroid Δ4-dehydrogenase; 5α-reductase; steroid 5α-hydrogenase; 3-oxosteroid 5α-reductase; testosterone Δ4-hydrogenase; 4-ene-3-oxosteroid 5α-reductase; reduced nicotinamide adenine dinucleotide phosphate:Δ4-3-ketosteroid 5α-oxidoreductase; 4-ene-5α-reductase; Δ4-3-ketosteroid 5α-oxidoreductase; cholest-4-en-3-one 5α-reductase; testosterone 5α-reductase
Systematic name: 3-oxo-5α-steroid:NADP+ Δ4-oxidoreductase
Links to other databases: BRENDA, EXPASY, KEGG, CAS registry number: 37255-34-8
References:
1. Shefer, S., Hauser, S. and Mosbach, E.H. Studies on the biosynthesis of 5α-cholestan-3β-ol. I. Cholestenone 5α-reductase of rat liver. J. Biol. Chem. 241 (1966) 946-952. [PMID: 5907469]