Novel 7beta-Hydroxysteroid Dehydrogenases and Their Use

Abstract

The invention relates to novel 7β-hydroxysteroid dehydrogenases which are obtainable from bacteria of the genus Collinsella, especially of the strain Collinsella aerofaciens, to the sequences encoding said enzymes, to methods for producing said enzymes and to their use in the enzymatic conversion of cholic acid compounds, and especially in the production of ursodeoxycholic acid (UDCS). The invention also relates to novel methods for the synthesis UDCS.

Description

RELATED APPLICATION DATA[0001]This application is a continuation of U.S. application Ser. No. 13 / 512,166, filed Oct. 23, 2013, which is the U.S. national phase, pursuant to 35 U.S.C. §371, of PCT international application Ser. No. PCT / EP2010 / 068576, filed Nov. 30, 2010, designating the United States and published in German on Jun. 3, 2011 as publication WO 2011 / 064404 A1, which claims priority to European Application Serial Nos. EP 09177544.5, filed Nov. 30, 2009, and EP 10008837.6, filed Aug. 25, 2010. The entire contents of the aforementioned patent applications are incorporated herein by this reference.[0002]The invention relates to novel 7β-hydroxysteroid dehydrogenases obtainable from bacteria of the genus Collinsella, in particular of the strain Collinsella aerofaciens, the sequences coding for these enzymes, methods for the production of the enzymes and the use thereof in enzymatic conversions of cholic acid compounds, and in particular in the production of ursodesoxycholic a...

AI Technical Summary

Benefits of technology

The patent is about a new method for making a chemical called UDCA, which is important for the production of other drugs. This method involves using an enzyme called 7β-HSDH, which is found in bacteria, to convert a compound called cholic acid into UDCA. The method has the advantage of being highly efficient, selective, and producing no byproducts. Overall, this patent provides a way to produce UDCA on a large scale using a recombinant enzyme system.

Problems solved by technology

A serious disadvantage inter alia is as follows: since the chemical oxidation is not selective, the carboxy group and the 3α and 7α-hydroxy group must be protected by esterification.

Disadvantages in this method are that because of the equilibrium position of the catalyzed reaction a complete conversion is not possible, and that for the first step of the conversion two different enzymes must be used, which increases the process cost.

A disadvantage in the cofactor regeneration used there is that the coproduct formed can only be removed from the reaction mixture with great difficulty, so that the reaction equilibrium cannot be favorably influenced, which results in incomplete conversion of the educt.

However, a disadvantage in this method is the use of a 7β-HSDH from the pathogenic microorganism Clostridium absonum, and the need preparatively to purify the enzyme from the bacterial extract which additionally possesses undesired 7α-HSDH activity.

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