Clostridium sardiniense 7alpha-hydroxy steroid dehydrogenase mutant R194A

Abstract

The invention relates to hydroxy steroid dehydrogenase, in particular to a clostridium sardiniense 7alpha-hydroxy steroid dehydrogenase mutant R194A. The amino acid sequence of the mutant is shown in SEQ ID NO:2, and the mutant is prepared by changing the 194 amino acid of 7alpha-hydroxy steroid dehydrogenase with the amino acid sequence of SEQ ID NO:1 into Ala from Arg. The catalytic efficiency of the mutant for substrates NADP+ and TCDCA is 3.34 times that of a wild type. The mutant R194A has great application potential in the industrial production process of biologically converting CDCA / TCDCA to obtain UDCA / TUDCA.

Description

technical field [0001] The invention relates to hydroxysteroid dehydrogenase, in particular to a mutant R194A of Clostridium sardinia 7α-hydroxysteroid dehydrogenase. Background technique [0002] The asymmetric reduction of carbonyl groups has always been one of the hotspots in chemical reaction research. Although the current chemical methods have achieved certain results, they often have disadvantages such as limited types and numbers of catalysts, low stereoselectivity, expensive auxiliary reagents, and difficult recovery. The enzymatic reaction not only has high efficiency, chemoselectivity, regioselectivity but also high stereoselectivity. The enzymatic reaction mediated by hydroxysteroid dehydrogenase (Hydroxysteroid dehydrogenase, HSDH) has relatively strict stereoselectivity and "relaxed" substrate specificity. For example, as early as the early 1980s, scientists have begun to use 7α-, 7β-HSDH produced by microorganisms to combine epimerization with chenodeoxycholi...

AI Technical Summary

Problems solved by technology

Although the current chemical methods have achieved certain results, there are often disadvantages in chemical methods such as limited types and numbers of catalysts, low stereoselectivity, expensive auxiliary reagents, and difficult recovery.

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