Pharmazell Gmbh

Christina Kantzow

Werner Hummel

Daniel Bakonyi

Dirk Weuster-Botz

Arno Aigner

Michael Braun

Boqiao Sun

Sven Bresch

In various aspects and embodiments, the invention provides a nucleic acid molecule comprising a nucleotide sequence encoding a 7β-hydroxysteroid dehydrogenase (7β-HSDH) mutant that catalyzes at least the stereospecific enzymatic reduction of a 7-ketosteroid to the corresponding 7-hydroxysteroid, wherein the mutant has, compared to the wildtype 7β-HSDH of SEQ ID NO:2, a decreased substrate inhibition and/or an altered cofactor usage, and the mutant has, in comparison with the wildtype 7β-HSDH of SEQ ID NO:2, 1 to 15 amino acid additions, substitutions, deletions and/or inversions in the sequence motif VMVGRRE corresponding to positions 36 to 42 of SEQ ID NO:2.

7β-hydroxysteroid dehydrogenase mutants and process for the preparation of ursodeoxycholic acid

The invention relates to novel 7&#xdf;-hydroxysteroid dehydrogenase mutants, to the sequences which encode these enzyme mutants, to processes for the preparation of the enzyme mutants and to their use in enzymatic reactions of cholic acid compounds, in particular in the preparation of ursodeoxycholic acid (UDCS). The invention also relates to novel processes for the synthesis of UDCS using the enzyme mutants; and to the preparation of UDCS using recombinant, multiply-modified microorganisms.

7Beta-hydroxysteroid dehydrogenase mutants and process for the preparation of ursodeoxycholic acid

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Munich, Germany

Christina Kantzow