Description
In enzymology, a 3alpha-hydroxysteroid dehydrogenase (B-specific) (EC 1.1.1.50) is an enzyme that catalyzes the chemical reaction: androsterone + NAD(P)+ ↔ 5alpha-androstane-3,17-dione + NAD(P)H + H+. The 3 substRates of this enzyme are androsterone, NAD+, and NADP+, whereas its 4 products are 5alpha-androstane-3,17-dione, NADH, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor, more specifically it is part of the group of hydroxysteroid dehydrogenases.
Abbr
3α-HSD, Recombinant (B. choshinensis)
Appearance
White lyophilizate
Enzyme Commission Number
EC 1.1.1.50
Activity
> 30 U/mg lyophilizate
Molecular Weight
ca. 41 kDa
Michaelis Constant
2.4 x 10^-5 M (androsterone) 3.0 x 10^-6 M (NAD)
Structure
2 subunits of 25 kDa (SDS-PAGE)
Unit Definition
One unit (U) is defined as the amount of enzyme which produces 1 μmol of NADH per min at 25°C and pH 8.9.
Optimum temperature
50–60°C
Thermal stability
below 45°C
Stability
stable at 37°C for at least four weeks
Synonyms
hydroxyprostaglandin dehydrogenase; 3α-hydroxysteroid oxidoreductase; sterognost 3α; 3α-hydroxysteroid dehydrogenase (B-specific); 3α-hydroxysteroid 3-dehydrogenase (B-specific); 3α-hydroxysteroid:NAD(P)+ 3-oxidoreductase (B-specific); EC 1.1.1.50