The invention relates to novel 3-hydroxysteroid dehydrogenase mutants, to the sequences which code for these enzyme mutants, to processes for the preparation of the enzyme mutants and to their use in enzymatic conversions of cholic acid compounds, in particular in the preparation of ursodeoxycholic acid (UDCA); subject-matter of the invention is also novel processes for the synthesis of UDCA using enzyme mutants; and the preparation of UDCA using recombinant, multiply modified microorganisms.

Chimeric polypeptides comprising a dihydrotestosterone (DHT) reductase moiety, such as 3 alpha-hydroxysteroid dehydrogenase (3α-HSD), fused to a signal peptide moiety, polynucleotides encoding same, and compositions comprising at least one microorganism cell capable of secreting the chimeric polypeptide, are provided. Further provided are methods and kits for treating, preventing or ameliorating androgen-dependent disorders, including but not limited to androgenic alopecia.

The invention provides novel 3α-hydroxysteroid dehydrogenase mutants, sequences that code for these enzyme mutants, methods for producing the enzyme mutants, and the use thereof in enzymatic reactions of cholic acid compounds, and in particular in the production of ursodeoxycholic acid (UDCA). The invention further provides processes for the synthesis of UDCA using the enzyme mutants and the production of UDCA using recombinant microorganisms that have been subjected to multiple modifications.

The invention provides novel 3-hydroxysteroid dehydrogenase mutants, sequences that code for these enzyme mutants, methods for producing the enzyme mutants, and o the use thereof in enzymatic reactions of cholic acid compounds, and in particular in the production of ursodeoxycholic acid (UDCA). The invention further provides processes for the synthesis of UDCA using the enzyme mutants and the production of UDCA using recombinant microorganisms that have been subjected to multiple modifications.

Chimeric polypeptides comprising a dihydrotestosterone (DHT) reductase moiety, such as 3 alpha-hydroxysteroid dehydrogenase (3-HSD), fused to a signal peptide moiety, polynucleotides encoding same, and compositions comprising at least one microorganism cell capable of secreting the chimeric polypeptide, are provided. Further provided are methods and kits for treating, preventing or ameliorating androgen-dependent disorders, including but not limited to androgenic alopecia.