Enzymatic dehydrogenation of steroids by beta-hydroxysteroid dehydrogenase in a two-phase system

The catalytic activity of β-hydroxysteroid dehydrogenase on 3β- or 17β-hydroxysteroids was studied when the reaction was carried out in a two-phase system where the enzyme and the cofactor were in the water phase and the substrate was predominantly in the organic phase.With some organic solvents the enzyme displayed its activity over a long period. Large amounts of steroids could be transformed in small volumes, using low enzyme concentrations.The kinetics of the reaction in the two-phase system as a function of substrate, enzyme concentrations, and pH as well as the equilibrium position were examined.